Dissertations / Theses on the topic 'Vitamin C – Physiological effect'

The aim of this study was to examine whether vitamins E (200 IU) and C (1 g) in combination would influence exercise-induced lipid peroxidation to a greater extent than vitamin E (400 IU) alone. A placebo-controlled study was carried out on 7 collegiate cyclists who were supplemented with 1) vitamin C (1 g); 2) vitamins E (200 IU) and C (1 g); and vitamin E (400 IU) during 3 treatments, each 3 weeks in duration. The serum concentrations of hematocrit and MDA, one marker of lipid peroxidation, were measured immediately before, immediately after, and 24 hours after each exercise bout. After the vitamin C treatment, MDA serum concentration of the athletes (n=7) increased 85% above the baseline values of the placebo values, the vitamin E/C treatment showed a 29% increase, and the vitamin E treatment showed a 39% decrease. Pre- to post-exercise serum MDA levels increased 64% in the placebo group, a 29% increase in the vitamin C treatment group, a 23.2% increase in the vitamins E/C treatment group, and a 46.9% increase in the vitamin E treatment group. It is concluded that exercise-induced lipid peroxidation is more greatly influenced post-exercise by a combination of vitamins E (200 IU) and C (1 g), than by either vitamin C (1 g) alone, or vitamin E (400 IU) alone.
Department of Family and Consumer Sciences

Male weanling inbred, mice were inoculated with fibrosarcoma cells (hindquarter) originally produced by 2-methylcholanthrene. Before inoculation, mice were randomly divided into three groups of 24 and one of 12 (control). After a one week acclimation period, each group was fed a diet containing either suboptimal vitamin B-6, 0.5 mg/kg diet; adequate, 7.0 mg/kg diet; or excess, 100 mg/kg diet. Controls were fed the adequate vitamin. B-6 diet. Twenty-four hours after tumor cell inoculation, a series of sodium selenite injections (0.5 μg/.10 mL) were given to half of each treatment group and all controls. Mice were sacrificed two wk after tumor inoculation. Tumors were excised and weighed. Selenium-treated mice had significantly smaller tumors as compared to untreated mice regardless of vitamin B-6 treatment. The smallest tumors were found in the selenium-treated group maintained on adequate B-6, while the largest tumors were developed by mice on the excess B-6 diet without selenium treatments. All groups had similar blood selenium levels as measured by gas chromatography. Tumor selenium levels, analyzed by atomic absorption, were significantly higher for untreated groups than selenium-treated groups (larger tumor size). The excess and adequate vitamin B-6 selenium-treated groups had significantly lower tumor selenium levels than the adequate vitamin B-6 untreated group. Plasma pyridoxal phosphate (concentrations) determined radiometrically and tumor vitamin B-6 levels determined microbiologically, related directly to dietary treatments. Sodium selenite injections and adequate vitamin B-6 diets reduced the size of fibrosarcomas in BALB/c inbred mice.
Master of Science

Thesis (PhD) -- Macquarie University, Division of Environmental and Life Sciences, Dept. of Chemistry and Biomolecular Sciences, 2007.
Bibliography: leaves 295-322.
Generation of peroxide groups in proteins exposed to a wide variety of reactive oxygen species (ROS) requires an initial formation of protein carbon-centred or peroxyl free radicals, which can be reduced to hydroperoxides. Both protein radicals and protein hydroperoxides are capable of oxidizing important biomolecules and thus initiate biological damage. In this study, we investigated the inhibition of protein hydroperoxide formation by ascorbate and GSH in gamma-irradiated HL-60 cells.--We used HL-60 cells as a model for general protection of living organisms by ascorbate (Asc) and glutathione (GSH) from the deleterious effects of protein hydroperoxides generated by radicals produced by gamma radiation. Measurement by HPLC indicated that incubation of HL-60 cells with Asc in the presence of ascorbate oxidase resulted in the accumulation of intracellular Asc. The intracellular Asc levels were lowered by irradiation, demonstrating intracellular consumption of Asc by the radiation-generated radicals. Exposure of HL-60 cells to increasing gamma irradiation doses resulted in increasing accumulation of protein peroxides in the cells. This was measured by the FOX assay. A significant decrease in intracellular protein hydroperoxides was noted when the cells were treated with ascorbic acid before irradiation. A dose-dependent protective effect of Asc was observed. Asc loading also provided strong protection from radiation-generated protein hydroperoxides independently of the composition of the external medium, showing that only the radicals formed within the cells were effective in oxidizing the cell proteins. Similarly, protein peroxidation was inhibited in cells with enhanced levels of GSH and increased when the intracellular GSH concentration was reduced. These findings indicate that ascorbate and GSH are important antioxidants in protecting cells from oxidative stress associated with the generation of protein hydroperoxide.
Mode of access: World Wide Web.
xxix, 322 leaves ill

Thesis (MSc) -- Stellenbosch University, 1990.
ENGLISH ABSTRACT: The main aim of this workpiece was to establish the physiological parameters against which a vitamin Bu deficiency could be measured. A comparison between the hematological values of healthy patients and those suffering from pernicious anemia due to vitamin Bu deficiency was done. A specific case of pernicious anemia was used in the comparison of abnormal values to the values of normal healthy patients. The comparison consisted of blood analyses with the help of specified instruments, photomicrographs of bone marrow and blood smears and statistical data. A Coulter Counter Model ZF was used for the hematological analyses of blood, a radio-isotope assay for serum vitamin B u was done and photomicrographs were taken with a NIKON Microflex camera with photomicrographic attachments. The importance of vitamin Bu has been shown in this workpiece. With the use of techniques and certain instruments, the effects of a shortage of vitamin Bu has been shown. Analyses of the blood from normal ,healthy patients was compared to that of patients suffering from pernicious anemia. It was demonstrated that pernicious anemia is characterized by a low erythrocyte count, hematocrit (Het), hemoglobin (Hb) and vitamin Bu levels together with a higher mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV). In severe cases of pernicious anemia these levels are extremely high or low as the case may be. Together with these values, the investigation of pernicious anemic blood and bone marrow smears revealed abnormally large erythrocyte precursors and fewer leucocytes than normal. Abnormally shaped cells, called macrocytes, were seen which was due to the disruption in deoxyribonucleic acid (DNA) synthesis caused by the vitamin Bu deficiency. This study produced a set of hematological reference values. The comparative study between healthy and pernicious anemic patients demonstrated a significant drop in serum vitamin B12 values during pernicious anemia. The hematological effect was illustrated by the Coulter Counter blood analysis results and the microscopic examination revealed the presence of megaloblastic erythrocytes, oval erythrocytes, pear-shaped poikilocytes and polymorphonuclear neutropbils with hypersegmented nuclei in blood smears I during vitamin B12 deficiency. This dianoses can be supported by the presence of megaloblasts and metamyelocytes in pernicious anemic bone marrow.
AFRIKAANSE OPSOMMING: Die hoof doel van hierdie werkstuk was om fisiologiese grense te bepaal waarteen 'n vitamien B12 tekort gemeet kan word. 'n Vergelyking tussen die hematologiese waardes van gesonde persone en die van pasiente met pernisieuse anemie wat ontstaan het as gevolg van 'n vitamien B12 tekort was uitgevoer. Die waardes verkry vanaf 'n spesifieke geval van pernisieuse anemie. was vergelyk met waardes vanaf normale gesonde persone. Hierdie vergelyking het bestaan uit bloed analises, fotomikrograwe van bloed en beenmurg smere en statistiese data. Die hematologiese bloed analises was met behulp van 'n Coulter Teller model ZF uitgevoer. 'n Radio-isotoop bepaling vir serum vitamien B12 was gedoen en fotomikrograwe was met 'n NIKON Microflex kamera geneem. Die belang van 'n vitamien B12 tekort was in hierdie werkstuk gedemonstreer. Die effek van hierdie tekort is deur die gebruik van sekere instrumente en tegnieke aangedui en die resultate hiervan is vergelyk tussen gesonde persone en pasiente met 'n vitamien B12 tekort. Hierdie studie het bevestig dat pernisieuse anemie gekenmerk word deur verlaagde eritrosiet, hematokrit (Het), hemoglobien (Hb) en vitamien B12 vlakke tesame met verhoogde gemene korpuskulere hemoglobien (GKH) en gemene korpuskulere volume (GKV) vlakke. Gedurende ernstige gevalle van pernisieuse anemie kan hierdie waardes uitermatig hoog of laag wees. Benewens hierdie waardes het die ondersoek van bloed en beenmurg gedurende vitamien B12 tekort, abnormale groot eritrosiet voorgangers en 'n verminderde hoeveelheid leukosiete getoon. Abnormale sel vorms was ook sigbaar a.g.v. die onderbreking in DNA sintese wat deur 'n vitamien B12 tekort veroorsaak word. Pernisieuse anemie word verkry wanneer daar 'n vitamien B12 en/of folaat tekort in die dieet is of wanneer hierdie vitamiene nie geabsorbeer kan word nie. Die teenwoordigheid van makrosiete, ovaal eritrosiete, peervormige poikilosiete en polimorfonuklere neutrofiele met hipergesegmenteerde keme in bloedsmere dui op 'n megaloblastiese anemie. Hierdie diagnose kan ondersteun word deur die aanwesigheid van megaloblaste en reuse metamielosiete in die beenmurg. Die bepaling van vitamien B12 en folaat vlakke in die bloed kan as addisionele bewysstukke vir 'n volledige diagnose dien. Gedurende hierdie studie is daar 'n stel hematologiese verwysingswaardes vasgestel. Die vergelykende studie tussen gesonde persone en pasiente met pernisieuse anemie het getoon dat daar 'n beduidende verlaging in serum vitamien B12 waardes gedurende pernisieuse anemie is. Die hematologiese effek was ook duidelik waameembaar in die Coulter teller se bloed analiese en mikroskopiese ondersoeke het die · teenwoordigheid van makrosiete, ovaal eritrosiete, peervormige poikilosiete en polimorfenuklere neutrofiele met hipersegmenteerde keme in bloedsmere aangedui. Hierdie diagnose kan ondersteun word deur die aanwesigheid van megaloblaste en reuse metamielosiete in die beenmurg.
This study was financially aided by a bursary from the CSIR.

Ultraviolet (UV) radiation damages both eukaryotic and prokaryotic cells by causing the formation of free radicals which damage cell membranes and DNA. Antioxidant vitamins have been shown to protect cells from UV-induced damage by scavenging free radicals. The protection of skin and its normal flora is necessary for the health of individuals in resisting diseases caused by microorganisms and delaying the long-term damage caused by UV radiation.This research investigated the effects of the antioxidants vitamin A and ascorbic acid, as well as UV-irradiation on both prokaryotic (Staphylococcus epidermidis) cells and eukaryotic (human fibroblast skin) cells. This information is important in determining the effects of vitamin treatment on skin and its normal flora.Results indicate that ascorbic acid is rapidly (within six hours) degraded after being dissolved in water or medium. Treatment of cells with ascorbic acid must take into account this rapid degradation. S.epidermidis cells were protected from UV-induced damage by treatment with ascorbic acid but were more sensitive to UV-irradiation when treated with vitamin A. Human fibroblast cells treated with ascorbic acid did not exhibit morphological changes when compared to untreated cells.
Department of Biology

Levels and turnover of vitamin E ($\alpha$-T) were studied in guinea pigs placed for three weeks on a diet containing a scorbutic level of vitamin C and either a low level (LE group) or a high level (HE group) of hexadeuterium-labelled vitamin E (d$\sb6$-RRR-$\alpha$-T acetate). The levels of vitamin C in the ten tissues analyzed declined very rapidly at rates that were the same in both the LE and HE groups, indicating that the level of dietary vitamin E had no effect upon tissue vitamin C levels. On the vitamin C deficient diet, the total $\alpha$-T (d$\sb0$- + d$\sb6$-$\alpha$-T) declined significantly over 21 days in the HE group in two tissues with high P-450 enzyme activity and in one tissue with a high partial pressure of oxygen, whereas on a vitamin C-sufficient diet with the same concentration of vitamin E the levels of total $\alpha$-T remained steady in the same tissues. In the LE "scorbutic" group, the total $\alpha$-T declined only in heart and kidney, whereas in the vitamin C-sufficient LE group there was a decline of total $\alpha$-T in all tissues analyzed except brain. The results show that in guinea pigs, at least, vitamin C is indispensable for proper uptake of vitamin E from the gut and absorption into tissues. Changes of vitamin E levels also were studied in six anatomical regions of the brain of rats subjected to controlled ischemia/reperfusion. Analysis showed that ischemia/reperfusion caused statistically significant losses of vitamin E in all regions, except the pons-medulla, and the extent of loss correlated well with the previously determined deterioration of the blood-brain barrier in the corresponding regions. (Abstract shortened by UMI.)

This thesis examines the effect of combined vitamin E succinate and Asc supplementation on the in vitro growth of a non-malignant monkey kidney (LLCMK) and a malignant melanoma (BL6) cell line, with nutritional concentration ranges of 5-20µg/ml and 25-50µg/ml respectively. Vitamin E and C are thought to interact synergistically to inhibit tumour cell growth by virtue of their antioxidant properties, whereby they quench free radicals and terminate lipid peroxidation. Furthermore vitamin E and C are thought to modulate the biosynthetic pathways in arachidonic acid metabolism at a number of different points. This may also offer a means of regulating tumour cell growth. It is well documented that vitamin E and C are distributed in the lipid and aqueous phases in the cell respectively. However, the cells need to obtain the vitamins from the environment in which they are found in order to exert a growth inhibitory effect. Supplementation of combined vitamin E succinate and Asc on BL6 and LLCMK cells resulted in a significant increase in LLCMK cell growth, and a significant decrease in cell growth was observed in BL6 cells. Vitamin E succinate in its esterified form cannot function as an antioxidant and requires the cleavage of the succinate to become an active antioxidant. The metabolism of vitamin E succinate to form free vitamin E in LLCMK and BL6 cells resulted in the cleavage of the succinate group from the vitamin E molecule in BL6 cells only, thus suggesting that an esterase may be present in BL6 cells. This would allow for a synergistic interaction between the two vitamins. The arachidonic acid cascade generates a family of bioactive lipids that modulate diverse physiological and pathological responses including tumour growth and promotion. The enzyme prostaglandin endoperoxide synthase (PGHS) or cyclooxygenase (Cox) is the key enzyme in the biosynthetic pathway leading to the formation of prostaglandins. Two enzyme isoforms of Cox have been identified, Cox 1 and Cox 2. Supplementation with vitamin E succinate and Asc at a combination 20:25µg/ml respectively resulted in a trend of increasing Cox activity over 12 hours suggesting that vitamin E and Asc have a stimulatory effect on Cox activity in BL6 cells. The inhibitors of Cox 2, dexamethasone, showed a decreasing trend in Cox activity at the 20:25µg/ml combination, while cycloheximide showed an initial stimulatory effect and then a gradual decrease in Cox activity. The elimination of the Cox activity by dexamethasone suggests that transcriptional regulation may be occurring in BL6 cells. We examined by Northern blot analysis whether combined supplementation of vitamin E succinate and Asc caused an elevation of Cox 2 RNA expression in BL6 cells. An inducible effect of Cox 2 was observed after 2 hours of supplementation with a combination of vitamin E succinate and Asc in BL6 cells, however the results are inconclusive and further studies are required to substantiate this finding.

The purpose of this study was to examine collegiate female swimmers' attitudes toward gender and coaching. The study also examined the coaching styles of male and females coaches and determined whether a difference between styles existed. A purposeful sample of 250 female swimmers from the Mid-American Conference (MAC) during the 2001-2002 swimming season participated in the study. Swimmers were required to have been coached by both female and male coaches in order to be eligible to participate. Addressing the purpose of this study, participants were asked to complete a 30-item questionnaire developed by the researcher. Frequency counts revealed that 23 of the 57 participants preferred a male coach to a female coach. Only two individuals reported their preference for a female with 32 participants citing no gender preference. Two sections, including 14 questions for each gender on the Gender Preference Instrument, assessed coaching style. Independent t -tests were calculated on each question (p < .05). Eight significant gender differences were observed on coaching styles, with the participating athletes scoring the male coach higher on all of the eight categories.
School of Physical Education

[Truncated abstract. Please see the pdf format for the complete text.] Interest in the role of peroxynitrite in the pathogenesis of atherosclerosis has increased due to many in vitro studies which have demonstrated its potent oxidising and nitrating capability and immunohistochemical staining studies which demonstrate nitration of tyrosine in vivo. It is frequently suggested that the production of nitric oxide and superoxide at sites of inflammation implicates peroxynitrite as the major damaging reactive nitrogen species in vivo. Evidence for a role for peroxynitrite is often demonstrated by measurement of 3-nitrotyrosine yet even this cannot distinguish peroxynitrite from other nitrating species. Clearly, however, if peroxynitrite is important in atherogenesis, then identification of mechanisms for its detoxification could provide a means of preventing such effects. Therefore, this Thesis has sought to determine whether phenolic compounds of dietary origin can be preferentially nitrated by reactive nitrogen species thereby protecting endogenous structures, such as low density lipoproteins, from atherogenic modifications. This Thesis focuses upon phenolic acids as they have received relatively less attention than other classes of phenolic compounds, such as flavonoids, yet they are quite abundant in socially important beverages such as red wine. In order to complete the required analyses, the development of methods to detect phenolic acids and their nitration products together with 3-nitrotyrosine, dityrosine and 5-nitro-γ-tocopherol was necessary. The initial in vitro experiments described herein sought to determine the products of reaction of peroxynitrite with phenolic acids of the 4-hydroxy and 3,4-dihydroxy type and then to examine whether these products could account for a protective effect upon tyrosine, lipids and endogenous anti-oxidants, if any was observed, when isolated LDL was treated with SIN-1, which releases peroxynitrite through the simultaneous generation of nitric oxide and superoxide. A concurrent minor focus was to examine the relationship between structure and activity of these phenolic acids under various regimes of oxidative insult. These experiments indicate that, at least in this in vitro model, oxidation is a dominant mechanism over nitration. Peroxynitrite was shown to nitrate coumaric acid in moderate yields but exclusive oxidation of caffeic acid appeared to occur. Although a potential role for γ-tocopherol as an anti-nitration agent was inferred, all types of chemical treatment of LDL in the presence of phenolic acids yielded oxidation as the primary end point. In fact, nitration of tyrosine was not detected and nitration of coumaric acid was at the limit of detection. Since nitration of tyrosine is generally regarded as important in many disease states, a more physiological nitrating mechanism involving artificially stimulated neutrophils was used. This system demonstrated that although physiologically relevant reactive nitrogen species can result in nitration of phenolic compounds, in a complex system including biological structures (LDL) and phenolic compounds, oxidation but not nitration of all species appears to occur. As a consequence of the results above, an examination of carotid plaque was undertaken to determine to what extent nitration occurred relative to oxidation in atherosclerotic tissue. These studies applied methods developed herein to detect 3-nitrotyrosine and dityrosine in complex biological matrices as markers of nitration and oxidation respectively. The data obtained demonstrated that nitration was a minor modification of protein (0.01%) compared to oxidation (0.3%) even in a highly diseased tissue such as carotid artery plaque. A secondary study examining plasma revealed that dityrosine, which has been implicated in irreversible albumin aggregation in chronic renal failure and more recently in heart disease, is elevated in chronic renal failure subjects compared to well matched controls. A separate examination of plasma from healthy subjects revealed that in both the fasting and post prandial state 3-nitrotyrosine could not be detected and, in fact, interfering species could be problematic in the GC-MS analysis of 3-nitrotyrosine. The lack of nitration of any substrate observed in vitro using reactive nitrogen species generated in the aqueous phase, the relative lack of nitration of tyrosine in plaque proteins and the lipophilicity of nitric oxide, the precursor of all reactive nitrogen species, suggested that nitration could be more closely associated with lipid structures. The known ability of γ-tocopherol to form 5-nitro-γ-tocopherol was used to probe this concept. The 5-nitro-γ-tocopherol content of lipid extracts obtained from carotid artery plaques was very high (30%). This indicated that nitration is predominantly a lipid phase phenomenon and that nitrating species are present in much greater abundance than oxidising species in vivo.

To examine the effects of fat composition and supplemental vitamin E (Vit E) and selenium (Se) on in vivo lipid peroxidation, diet-induced hypercholesterolemia, and glutathione (GSH) metabolism, male Syrian hamsters were fed for three weeks butter fat (BF-) or fish oil- (FO-)based diets supplemented with Vit E and/or Se. The effect of supplemental Vit E and Se on tissue lipid peroxidation (LPO), glutathione peroxidase (GSH-Px) activity and GSH concentrations differed between heart and liver and also was affected by dietary fat. The reduced glutathione/oxidized glutathione (GSH/GSSG) ratio was more consistently associated with tissue lipid peroxidation than was tissue Vit E content. Plasma lipids were lowered with supplemental Se and Vit E. Se supplementation, however, exerted a more potent hypolipidemic effect than Vit E. A pro-oxidative action of Se in hearts of FO-fed hamsters was noted, which was inhibited by supplemental Vit E. Hence, the combination of Vit E and Se may offer the most benefit against diet-induced oxidative stress and hyperlipidemia.

Thesis (B. Sc.(Hons.))--University of Adelaide, Dept. of Physiology, 1997.
Spine title: Effect of vitamin C on chromosome damage, apoptosis and necrosis. Includes bibliographical references (leaves 30-34).

Findings were that caregivers considered all items on the Information Needs and Patient Care Needs subscales to be important but most of the unmet needs were from the Patient Care subscale. The needs less satisfied in relation to importance were (a) ways to improve patient appearance, (b) activities that will make patient feel purposeful, (c) information on how to give medications, (d) ways to reassure patient, (e) ways of coping with patient's diagnosis, (f) ways to dress patient comfortably, (g) ways to deal with patient's decreased energy, and (h) importance of not leaving patient alone.The implications for nursing are to assess and anticipate the needs of the caregiver of the stroke survivor so that his or her needs can be met. Preparing caregivers for their new role by meeting their needs will help the nurse met the primary goal of helping the patient.
School of Physical Education

This purpose of this study was to determine the effects of vitamin E and/or resistance exercise on insulin resistance and glucose uptake. Nine subjects, who were currently active but not strength training, were assigned to either the vitamin E or placebo group based on their prescreening measurements. Subjects underwent a 3-week vitamin E washout period before testing. At baseline testing subjects were given a 75-gram glucose load and blood was drawn every 15-minutes for 2-hours to analyze insulin and glucose response. Another oral glucose tolerance test (OGTT) was performed 45minutes after a 50-minute full body progressive resistance training session to determine insulin and glucose response to exercise. Subjects ingested either the placebo (3 capsules of olive oil) or 1200 IU vitamin E (3 capsules) for 9-weeks. After 3-weeks of supplementation the subjects returned for another exercising OGTT. After this session the subjects began a 6-week progressive resistance exercise program, in which they performed another OGTT after the last session. Both groups showed a significant increase in strength gains pre and post resistance training. The statistical analysis failed to demonstrate any differences between groups in insulin or glucose response in any of the four OGTT trials, but there were multiple trends present. Combining vitamin E supplementation with resistance training increased insulin sensitivity and the disposal of glucose. Both groups also had significant strength gains from pre to post study. Future research is needed for verification of these trends.
School of Physical Education

Background: Inverse associations have been reported between homocysteine concentrations and poor cognitive performance in several cross-sectional studies of healthy elderly subjects. Folate supplementation with or without vitamins B-12 and B-6 is an effective means of lowering homocysteine concentrations. Mood disturbances, from mild mood changes to clinical depression, are common in older populations. Several studies have shown that depressed people have lower levels of folate and vitamin B-12 and higher levels of homocysteine than non-depressed people. Improvement of mood has been reported in depressed people following supplementation with folic acid. Clinical trials are required to determine if lowering homocysteine concentration with vitamins improves cognitive function and/or mood in healthy elderly participants. Objective: The primary aim of this research project was to carry-out a 2 year randomised, double-blind, placebo-controlled trial to determine if a supplement containing folate (1mg L-Mefolinic acid), vitamin B-12 (500(mu)g) and vitamin B-6 (10mg) improves scores or prevents decline on tests of cognition in a group of healthy older people ([greater than or equal to]̲ 65 years) with a plasma homocysteine concentration [greater than or equal to]̲13 (mu)mol/L. A second aim of this study was to determine if homocysteine lowering vitamins improved scores on tests of mood in this group. Methods: Four hundred and sixty-five individuals, aged 65 and over, were recruited from Dunedin and surrounds, and asked to attend a screening clinic and provide a fasting blood sample. Two-hundred and seventy-six volunteers with a plasma homocysteine concentration [greater than or equal to]13(mu)mol/L were randomised to take either a combination of 1mg L-Mefolinic acid, 500(mu)g vitamin B-12 and 10mg vitamin B-6 or placebo for 2 years. A battery of cognitive tests and indices of mood was administered at baseline, one year, and two years. A fasting blood sample was collected at baseline and every six months thereafter. Results: From baseline to 6 months of the intervention, homocysteine concentrations decreased by 37.5%, from 16.7 to 10.5 (mu)mol/L in the vitamin supplemented group and then plateaued. In the vitamin supplemented group there was a 181% increase in red blood cell folate concentration from a mean of 977 to 2752 nmol/L, and a 90.1% increase in plasma vitamin B-12 (from a mean 283 to 538 (mu)mol/L) over the study period of two years. In the vitamin supplemented group there was a trend to poorer performance on almost all tests of cognition compared to placebo group. The vitamin group was 8% slower on Part B of the Reitan Trail Making Test, a test of speeded attention, mental tracking, visual search and mental flexibility (p=0.009). The vitamin group scored significantly lower on tests of short-term recall, Weschler Paragraphs (p=0.03) after 2 years, and the Rey Auditory Verbal Learning Test ((p=0.04) after one year, than the placebo group. There was no difference in mood score by treatment in this largely non-depressed group. Conclusion: These results suggest a detrimental effect of high dose homocysteine lowering vitamin supplements on cognitive function in healthy older people. These results need to be confirmed in other randomised controlled trials.

Falls in the older population have devastating consequences on the psychological and physiological health of the individual. Due to the complexity of interacting factors associated with ageing, pathology and falling episodes, determination of a primary cause or set of causes has been difficult to establish. Deficits in components of neuromuscular control have been widely studied with the coordinated interaction of sensory and motor system components being presented as a fundamental factor in the reduction of falling episodes. A causal relationship between deficits in vitamin D status and falling episodes has also been suggested. Furthermore, a relationship between poor vitamin D status, falling episodes and poor neuromuscular performance has been reported. The aims of the current study were designed to advance understanding in three aspects of the problem of falls prevention. Firstly an examination of the reliability of testing procedures commonly used in assessment of falls risk was undertaken. The Physiological Profile Assessment (PPA) testing procedure was selected as a commonly used tool and the reliability of its various components (sensory, motor and balance) was undertaken as an independent assessment of this approach to assessing falls propensity. Secondly, a case control study of fallers and non fallers was undertaken in which the neuromuscular tests evaluated in the reliability study were used to assess differences in neuromuscular control. The influence of vitamin D status on these measures was also considered. Thirdly, a 12-month randomised controlled trial of vitamin D/calcium supplementation or placebo/calcium was undertaken to identify the effect on falls outcome and individual measures of neuromuscular control.

[Truncated abstract] Vitamin E is comprised of a family of tocopherols (TOH) and tocotrienols. The most studied of these is [alpha]-tocopherol ([alpha]-TOH), as this form is retained within the body and any deficiency of vitamin E is corrected with this supplement. [alpha]-TOH is a lipid-soluble antioxidant required for the preservation of cell membranes and potentially acts as a defense against oxidative stress. Individuals who have a primary vitamin E deficiency such as low birth weight infants, secondary vitamin E deficiency due to fat malabsorption such as in abetalipoproteinaemia, or a genetic defect in TOH transport require supplementation. There is debate as to whether vitamin E supplementation in other patient groups is required. Vitamin E supplementation has been recommended for persons with FHBL, a rare disorder of lipoprotein metabolism that leads to low serum [alpha]-TOH and decreased LDL cholesterol and apolipoprotein B concentrations. We examined the effect of truncated apoB variants on vitamin E metabolism and oxidative stress in persons with heterozygous FHBL. We used HPLC with electrochemical detection to measure [alpha]- and [gamma]-TOH in serum, erythrocytes, and platelets, and GC-MS to measure urinary F2-isoprostanes and TOH metabolites as markers of oxidative stress and TOH intake, respectively. Erythrocyte [alpha]-TOH was decreased, but we observed no differences in lipid-adjusted serum TOHs, erythrocyte [gamma]-TOH, platelet [alpha]- or [gamma]-TOH, urinary F2-isoprostanes, or TOH metabolites. Taken together, our findings do not support the recommendation that persons with heterozygous FHBL should receive vitamin E supplementation. ... Sesame lignans are natural components of sesame seed oil and there is evidence that these lignans can inhibit CYP450 enzymes, in particular, those responsible for vitamin E metabolism. We hypothesised that sesame seed ingestion would increase serum [gamma]-TOH, lower plasma lipids and inhibit platelet function in human subjects with at least one cardiovascular risk factor. We used HPLC with electrochemical detection to measure [alpha]- and -TOH in serum and GC-MS to measure F2-isoprostanes and TOH metabolites as markers of oxidative stress and TOH intake, respectively. We used high-sensitive C-reactive protein as a measure of systemic inflammation. Platelet function was assessed using the PFA-100 platelet aggregation assay. Although serum [gamma]-TOH increased by 17%, we observed no effect on lipid metabolism, markers of inflammation, oxidative stress or platelet function following treatment with ~25 g/day sesame seeds for five weeks. Our findings challenge the hypothesis that sesame seed ingestion provides beneficial cardiovascular effects. In summary, we have studied the metabolism and transport of both [alpha]- and [gamma]-TOH in humans to evaluate the requirements for supplementation and the effects of vitamin E on platelet function and CYP3A4 activity. Specialised techniques using HPLC were developed to measure serum and cellular TOH concentrations both in supplemented and un-supplemented individuals. We also used GCMS to provide a sensitive, accurate assessment of TOH metabolites and midazolam pharmacokinetics in humans after vitamin E supplementation. We have examined the role vitamin E has on important biochemical endpoints, with emphasis on the implications for TOH supplementation in subjects at risk of CVD.

Exercise-induced muscle soreness and damage have been investigated for almost a century, and yet it appears that there is little that can be done to avoid these consequences of over-exertion, except train on a regular basis. It is likely that freeradicals are involved at a number of stages in the muscle damage process, and therefore the provision of appropriate antioxidants may theoretically offer some protection. One such antioxidant is vitamin C, although the literature available in support of this notion is scarce. The aim of these studies, therefore, was to assess whether different nutritional interventions using vitamin C would offer any benefit to exercise-induced muscle damage and soreness. In the past, investigators have often used exercise protocols designed to maximise the extent of injury. The studies reported in this thesis, however, used an exercise protocol (Loughborough Intermittent Shuttle Test: LIST) based on the multiple-sprint sports (e.g. football). Participation in such sports is very high, although frequently on an irregular basis, and therefore exercise of this nature may have the capacity to cause muscle damage and soreness. The LIST provided a suitable exercise model, and in different studies led to increases in soreness, markers of muscle damage, lipid peroxidation, and inflammation. It also led to poorer muscle function up to 72 h after exercise in some muscle groups. Short-term supplementation with vitamin C 2 hours before exercise successfully increased plasma and cellular concentrations, although failed to have any beneficial outcomes in terms of muscle damage or soreness. Supplementation in the hours and days (up to three days) after exercise also produced no beneficial effects, and it may be that supplementation occurred at an inappropriate time. Prolonged supplementation with vitamin C proved more promising (14 days), and was associated with reduced plasma concentrations of interleukin-6 and malondialdehyde. Furthermore, there were modest benefits to certain' aspects of muscle soreness and function, although these were not always statistically significant. However, tliere was no effect on circulating markers of muscle damage (creatine kinase and myoglobin). These findings suggest that the regular ingestion of vitamin C may be associated with some favourable changes following damaging exercise. However, the consumption of large amounts of vitamin C immediately before or after exercise offer no appreciable benefits, despite large changes in plasma concentrations of this vitamin.

Hemorrhagic Enteritis (HE) vaccine is perhaps the most commonly used vaccine in the turkey industry. Although it provides protection against clinical disease, the vaccine is still thought to produce transient immunosuppression. In the field, HE still remains a significant concern for turkey producers. Research conducted over the years has shown that management stressors such as movement of turkeys from brooding to finishing environments and the timing of these stressors may influence the short-term response to vaccination. Strategic stress application may be of benefit in the optimization of protective responses and the development of vaccination protocols without detrimental effects on performance. Ascorbic acid may also have important implications on social stress and may play a role in immunity and response to HE vaccination in turkeys. Trials were conducted to examine the interrelationship among social stress, nutrition (vitamin C), immunity and their influence on response to hemorrhagic enteritis virus (HEV) vaccination. Stress is unavoidable, however if it is managed properly, it can be beneficial. In this dissertation, it was first demonstrated that stress in the form of social disruption can have negative physiological and immunological effects on turkey poults and that these effects can be alleviated with the addition of 300mg/kg vitamin C to the diet. Secondly, it was also demonstrated that when stress is applied on the day of vaccination, response to HEV vaccination can be improved. Thirdly, vitamin C supplementation at 300mg/kg can improve responses to HEV vaccination. However, it was concluded that vitamin C supplementation during periods of simultaneous stress application and vaccination does not provide benefit to response to vaccination.
Ph. D.

Controlled release systems aim at achieving a predictable and reproducible drug release over a desired time period. These systems allow reduced dosing frequency, constant drug levels in the blood, increased patient compliance and decreased adverse effects. In a recent study, Chitosan beads, containing N-trimethyl Chitosan chloride, have shown a potential in the delivery of rifampicin. However, because of inadequate amounts of rifampicin released over 24 hours, incorporation of other pharmaceutical excipients to increase the swelling behaviour of the beads to improve drug release, was considered in this study. Chitosan beads were prepared through ionotropic gelation with tripolyphosphate (TPP) as a crosslinking agent. To increase the porosity if the Chitosan beads Explotab®, Ac-Di-Sol® and vitamin C were added individually to Chitosan solutions at concentrations of 0.1, 0.25 and 0.5 % w/v before adding the mixture to the TPP solution. Swelling and morphology studies were used in the evaluation of the different formulations. The swelling and morphology results were then used to select a set of combination and concentrations of two excipients sand then prepare and characterise beads containing two combinations. The combination formulations and formulations containing single excipients were then loaded with rifampicin. Pure chitosan beads exhibited a higher drug loading capacity (67.49 %) compared to the lowest loading capacity of 41.61 % exhibited by chitosan beads containing a combination of Explotab®, Ac-Di-Sol®.For all the other formulations the drug loading capacity ranged within 48 and 63 %. These formulations were used for dissolution studies over a period of 6 hours at pH 5.60 and 7.40. The dissolution results showed that no chitosan has dissolved at both pH values. A significant amount of rifampicin was, however, released from the beads, especially at pH 7.40. chitosan beads containing vitamin C also exhibited high rifampicin release (48.34 ± 1.00) %) at pH 5.60 compared to the other formulations and this makes vitamin C a potential excipient for enhanced drug release over a wide pH range (both acidic and alkalinic). However, further studies are necessary to optimise the preparation method to minimise drug loss during loading and to improve the drug loading capacity of the beads.
Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2005.

In controlled release applications a drug is molecularly dispersed in a polymer phase. In the presence of a thermodynamically compatible solvent, swelling occurs and the polymer releases its content to the surrounding medium. The rate of the drug release can be controlled by interfering with the swelling rate of the beads or by influencing diffusion through the viscosity of the polymer. Beads that contain chitosan were prepared through the ionotropic gelation method where tripolyphosphate (TPP) was used as the crosslinking agent. Beads that consisted of 3% w/v isoniazid (lNH) and 5% w/v chitosan were prepared in a 5% w/v TPP solution (pH 8.7) as the primary beads. To improve the drug loading of chitosan isoniazid beads (ClB) the TPP concentration, pH of the TPP solution and the INH concentrations were altered for maximum drug loading. To increase the porosity of the beads of chitosan beads Explotab® (EXPL), Ac-Di-Sol® (ADS) and Vitamin C (VC) were added individually to chitosan solutions at concentrations of 0.1, 0.25 and 0.5% w/v before adding the mixture to the TPP solution. Morphology, swelling and drug loading studies were used to evaluate the different formulations. After these excipients were added individually they were also added in combinations of two excipients respectively and characterised. From the results of the drug loading studies the beads that contained only chitosan and isoniazid showed a percentage drug loading of (43.92%) which is the best of all the beads that were analyzed. The multi excipient combination of Ac-Di-Sol® and Explotab® showed the best swelling capability at both pH levels. Dissolution studies were conducted on all the formu lations over a period of 6 hours (360 minutes) at pH 5.6 and pH 7.4. From the dissolution results it were clear that no chitosan dissolved at both pH values. The dissolution of single pharmaceutical excipient (SPE) and multi pharmaceutical excipient (MPE) formulations can be arranged in the following order: VC/ADS < VC < ADS/EXPL < ADS < VC/EXPL < CIB < EXPL. Explotab® is a potential excipient for enhanced drug release over a wide pH range.
Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2007.

Most of the load-bearing demand placed on the human body is transduced by skeletal tissue, and the capacity of the skeleton to articulate in various opposing directions is essential for body movement and locomotion. Consequently, cartilage and bone defects due to trauma, disease, and developmental abnormalities result in disabling pain and immobility for millions of people worldwide. A novel way of promoting cartilage and bone regeneration is through the incorporation of either primary cells or multipotent progenitor cells in a three-dimensional (3D) biomaterial scaffold, and/or the addition of exogenous growth and differentiation factors. The first part of this study reports a protocol for using freshly isolated mature chondrocytes seeded in a 3D hydrogel biomaterial scaffold, developed to explore mechanotransduction of engineered cartilage constructs cultured in a designed bioreactor. The bioreactor was designed to allow the application of physiological mechanical forces (compression and fluid flow), as well as a non-invasive/non-destructive method for analyzing regenerating tissue in real time through ultrasound transducers and a computerized monitoring system. In the second part of this study, an engineered immortalized osteoprecursor cell line, designated OPC1 (osteoblastic precursor cell line 1), was used as a culture model system for exploring the effects of exogenous growth and differentiation factors, mainly vitamin D, on early bone development. OPC1 was previously designed to provide a consistent reproducible culture system for direct comparisons of engineered bone constructs, evaluating bone development and cell/biomaterial interactions, and for investigating putative bone differentiating factors. One of the objectives of this research effort was to explore tissue development and regeneration by culturing OPC1 in the presence of vitamin D metabolites vitaD3 and 1,25OH2D3, while assaying the concomitant biological response. Results indicate that OPC1 is capable of metabolizing the parental metabolite vitaD3, and thus 25OHD3, to the active vitamin D form 1,25OH2D3. The metabolism of vita3 resulted in an anti-proliferative and pro-differentiative influence on OPC-1. These results support the hypothesis that extra-endocrine synthesis of 1,25OH2D3 functions in a tissue specific manner to regulate growth and differentiation, in addition to the classic calcimic actions of the vitamin D endocrine pathway. Understanding the influence of vitamin D on bone development will have significant implications on healthy aging, including the susceptibility to skeletal disorders involved in development and aging, such as osteoarthritis (OA) and osteoporosis.

Contents: Chitosan -- Controlled drug delivery -- Indomethacin -- Inotropic gelation -- Tripolyphosphate (TPP) -- Explotab® -- Ac-Di-Sol® -- Vitamin C
Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2007.

Dietary nitrite intake has been implicated in numerous gastrointestinal cancers in humans due to the formation of a group of carcinogens called N-nitroso compounds. The need to estimate their intake is vital in establishing at risk population and to monitor and perhaps one day manage their dietary intake. This is the first study to estimate nitrate and nitrite in selected vegetables, cured and fresh meat in Australian food supply using ion-paired reversed-phased HPLC. Nitrite content in meat products analysed ranged from 0 to 83.9 mg/kg in medallion beef and Frankfurt, respectively; nitrate content ranged from 18.7 mg/kg in minced beef to 142.5 mg/kg in salami. The nitrite content was below the maximum limit set by the Food Standards Australia and New Zealand. Nitrate content in selected vegetables ranged from 123 to 4850 mg/kg in Iceberg lettuce and English spinach, respectively; only minimal nitrite at 20 mg/kg was present in Gai choy, which was most likely due to bacterial contamination during storage. Based on the food consumption pattern of Australians, the dietary nitrite and nitrate intake from bacon were 1.51 and 3.42 mg per capita per day, which was below the Adequate Daily Intake set by the European Union Scientific Committee for food in 1995. Taking into considerations of oral nitrate reduction to nitrite and the endogenous nitrate formation, the upper extreme of dietary nitrite and nitrate intake in Australians were 44 and 2.4 times over the ADI, respectively. However, this does not take into effect of other dietary promoters and inhibitors. Eighteen healthy human volunteers were put on a low nitrate, nitrite and antioxidant diet for three days during which they were fed one serving of cured meat with and without 500 mg of vitamin C. Using GC-MS, N-nitrosodimethylamine was not detected in the urine before or after vitamin C supplementation, suggested that a diet low on nitrate and nitrite cannot produce NDMA and thus may reduce the risk of developing gastrointestinal cancers. Different extraction methods and combination of herbs and spices were demonstrated in vitro to show inhibition against B. cereus, Escherichia coli, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus. In addition, autoclaved turmeric powder at 0.3 % (w/v), hot water extracted turmeric with ginger at 0.5 % and rosemary at 1.0 % showed growth inhibition against Clostridium sporogenes, which was used as a surrogate for Clostridium botulinum. The use of these combinations of herbs and spices may replace or at least reduce the use of nitrite as a preservative in cured meat products to prevent botulism and reduce dietary nitrite intake.

TRPV channels play a role in both mammalian insulin signaling, with TRPV1 expression in pancreatic beta-cells, and in C. elegans insulin-like signaling through expression of OSM-9, OCR-1, and OCR-2 in stress response pathways. In response to a glucose-supplemented diet, C. elegans are know to have sensitivity to anoxic stress, exhibit chemotaxis attraction, and display reduced egg-laying rate. Transcriptome analysis reveals that glucose stimulates nervous system activity with increased transcript levels of genes regulating neurotransmitters. Ciliated sensory neurons are needed for a reduced egg-laying phenotype on a glucose-supplemented diet. Egg-laying rate is not affected when worms graze on glucose-supplemented Delta-PTS OP50 E. coli, which is defective in glucose uptake. This suggests a possible sensory neuron obstruction by exopolysaccharides produced by standard OP50 E. coli on glucose, eliciting a starvation response from the worm and causing reduced egg-laying rate. Glucose chemotaxis is affected in specific TRPV subunit allele mutants: ocr-2(vs29) and osm-9(yz6), serotonin receptor mutants: ser-1(ok345) and mod-1(ok103), and G-alpha protein mutant: gpa-10(pk362). TRPV deletion mutants had no effect on glucose chemotaxis, alluding to the modality role pf TRPV alleles in specific sensory neurons. The role of serotonin in a reduced egg-laying rate with glucose remains unclear.

[EN] Persimmon (Diospyros kaki L.) 'Rojo Brillante' is an astringent variety characterised by good growing conditions, excellent colour, size, sensory characteristics and good nutritional properties. In the last decade, its production has grown substantially in Spain given the application of high levels of CO2 to remove astringency while firmness is preserved. This technology has also increased its potential as a fresh-cut commodity. However, physical damage during processing result in degradation of the colour and firmness of the product and a higher susceptibility to microbial spoilage that significantly reduces the fruit's shelf life. The objective of the present thesis was to develop optimum procedures for processing and marketing 'Rojo Brillante' persimmon into a fresh-cut product with the maximum shelf life and best physicochemical, nutritional, sensory and microbiological quality. Firstly, the objective was to evaluate the effect of the maturity stage (MS) at harvest, storage time at 15 ºC before processing, and the application of different antioxidant treatments on enzymatic browning, sensory and nutritional quality of fresh-cut 'Rojo Brillante' persimmon during storage at 5 ºC. Concentrations of 10 g L-1 ascorbic acid (AA) or 10 g L-1 citric acid (CA) controlled tissue browning and maintained the visual quality of fresh-cut persimmon above the limit of marketability for 6-8 storage days at 5 ºC, depending on the MS. However, these acidic solutions reduced fruit firmness as compared to control samples. Further studies showed that the combination of these antioxidants with 10 g L-1 CaCl2 maintained firmness of the persimmon slices within the same range as the control samples. In another work, the application of 1-methylcyclopropene (1-MCP) allowed to process fruits after 45 days of storage at 1 ºC with commercial firmness and the antioxidant solution (10 g L-1 CA + 10 g L-1 CaCl2) extended the limit of marketability up to 9 days of storage at 5 ºC. Different controlled atmosphere conditions in combination with AA or CA dips were also evaluated as a first step to select optimum O2 and CO2 concentrations for modified atmosphere packaging (MAP) of fresh-cut 'Rojo Brillante' persimmons. Overall, the combination of antioxidant dips and a controlled atmosphere composed of 5 kPa O2 (balance N2) was proved to be the most effective combination to control enzymatic browning. This atmosphere maintained the visual quality of persimmon slices within the limit of marketability during 7- 9 days at 5 ºC. On the contrary, high CO2 concentrations (10 or 20 kPa) induced darkening in some tissue areas, associated with a flesh disorder known as 'internal flesh browning'. Later studies confirmed the beneficial effect of an active MAP in 5 kPa O2 compared to passive MAP to improve the visual quality of fresh-cut 'Rojo Brillante' persimmon, showing a synergic effect with the antioxidant dip (10 g L-1 CA + 10 g L-1 CaCl2). Antioxidant edible coatings were prepared from whey protein isolate (WPI), soy protein isolate (SPI), hydroxylpropyl methylcellulose (HPMC) and apple pectin as the polymeric matrix. All edible coatings were amended with the antioxidant combination selected (10 g L-1 CA + 10 g L-1 CaCl2). All the edible coatings tested proved effective to control enzymatic browning of persimmon slices. However, the samples treated with the HPMC- and pectin- based coatings were scored with a better visual quality that the rest of the treatments. In general, free radical scavenging activity and total carotenoid content increased in late-season persimmons; whereas, processing (cutting and storage at 5 ºC), antioxidant dips, controlled atmosphere storage or edible coatings had no clear effect on nutritional quality (vitamin C, free radical scavenging activity, total phenolic content, and carotenoids) of fresh-cut persimmons.
[ES] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' es un cultivar astringente que presenta unas propiedades organolépticas y nutricionales excelentes. En la última década, su cultivo en el área mediterránea de España se ha incrementado de manera exponencial con el desarrollo de la tecnología que permite eliminar la astringencia, manteniendo la firmeza del mismo. Esta nueva forma de presentación, aporta numerosas ventajas, entre la que se incluye la posibilidad de ser comercializado como fruta fresca cortada. Sin embargo, el éxito comercial del producto está limitado por el pardeamiento enzimático, la pérdida de firmeza y al crecimiento microbiano. En este contexto, el objetivo de la Tesis ha sido el desarrollo de caqui 'Rojo Brillante' fresco cortado mediante un enfoque que integra el estudio de las características del producto en el momento del procesado y de distintas tecnologías que mantengan la calidad físico-química, sensorial, nutricional y microbiológica del producto durante un periodo que permita su comercialización. En primer lugar, se evaluó el efecto del estado de madurez (MS) en el momento de recolección, el tiempo de almacenamiento a 15 ºC antes del procesado y la aplicación de diferentes antioxidantes en el pardeamiento enzimático y la calidad sensorial y nutricional del caqui 'Rojo Brillante' cortado y almacenado a 5 ºC. La aplicación de 10 g L-1 de ácido ascórbico (AA) ó 10 g L-1 ácido cítrico (CA) controló el pardeamiento enzimático y mantuvo la calidad visual del caqui por encima del límite de comercialización entre 6 y 8 días de almacenamiento a 5 ºC, dependiendo del MS. Sin embrago, la aplicación de estos antioxidantes redujo de manera significativa la firmeza del fruto respecto al control. La combinación de estos antioxidantes con 10 g L-1 de CaCl2 permitió mantener la firmeza en el mismo rango que las muestras control. En un trabajo posterior, la aplicación de 1-metilciclopropeno (1-MCP) permitió procesar caqui almacenado 45 días a 1 ºC con una buena firmeza comercial y el tratamiento antioxidante (10 g L-1 CA + 10 g L-1 CaCl2) consiguió alcanzar un límite de comercialización del producto de 9 días a 5 ºC. La evaluación de distintas atmósferas controladas en combinación con tratamientos antioxidantes (AA o CA), como paso previo al envasado en atmósfera modificada (MAP) del caqui, mostró como más efectiva en el control del pardeamiento enzimático la atmósfera compuesta por 5 kPa O2 (balance N2). Esta atmósfera mantuvo la calidad visual del caqui cortado dentro del límite de comercialización durante 7-9 días a 5 ºC. Por el contrario, la aplicación de altas concentraciones de CO2 (10 ó 20 kPa) dio lugar a un pardeamiento en ciertas zonas de la pulpa que se conoce como 'internal flesh browning'. Estudios posteriores confirmaron el efecto beneficioso del envasado de caqui cortado y tratado con solución antioxidante (CA-CaCl2) en una MAP activa de 5 kPa O2 en la calidad visual del fruto frente a la aplicación de una MAP pasiva. El desarrollo de recubrimientos comestibles con capacidad antioxidante se realizó mediante la incorporación de antioxidantes (10 g L-1 CA + 10 g L-1 CaCl2) a formulaciones a base de proteína de suero lácteo (WPI), proteína de soja (SPI), hidroxipropilmetilcelulosa (HPMC) y pectina. Todos los recubrimientos fueron efectivos controlando el pardeamiento enzimático del caqui cortado, siendo las muestras recubiertas con HPMC y pectina las mejor evaluadas visualmente. En general, el procesado, la aplicación de antioxidantes, el envasado en atmósferas controladas y los distintos recubrimientos comestibles estudiados, si bien no mostraron un efecto claro en los parámetros de calidad nutricional evaluados, no tuvieron un efecto negativo en los mismos. Por otra parte, los frutos cosechados a final de campaña tuvieron mayor actividad antioxidante y contenido en carotenoides.
[CAT] El caqui persimmon (Diospyros kaki L.) 'Rojo Brillante' és un cultiu astringent que presenta unes propietats organolèptiques i nutricionals excel¿lents. En la última dècada, el seu cultiu en l'àrea mediterrània d'Espanya s'ha incrementat de manera exponencial amb el desenvolupament de la tecnologia que permet eliminar l'astringència, mantenint la fermesa del mateix. Esta nova forma de presentació, aporta un gran nombre d'avantatges, entre els quals s'inclou la possibilitat de comercialitzar-lo com fruita fresca processada. No obstant, l'èxit comercial del producte està limitat per pardetjament enzimàtic, la pèrdua de fermesa i el creixement microbià. L'objectiu de la Tesis ha estat en el desenvolupament de caqui 'Rojo Brillante' tallat en fresc mitjançant un enfocament que integra l'estudi de les característiques del producte en el moment del processat i de diferents tecnologies en el manteniment de la qualitat físico-química, sensorial, nutricional i microbiològica del producte durant un període que permeta la seua comercialització. En primer lloc, es va avaluar l'efecte de l'estat de maduresa (MS) en el moment de recol¿lecció, el temps d'emmagatzemament a 15ºC abans del processat i l'aplicació de diferents tractaments antioxidants en el pardetjament enzimàtic i la qualitat sensorial i nutricional del caqui 'Rojo Brillante' tallat i emmagatzemat a 5 ºC. L'aplicació de 10 g L-1 d'àcid ascòrbic (AA) o 10 g L-1 d'àcid cítric (CA) va controlar el pardetjament enzimàtic i va mantenir la qualitat visual del caqui per damunt del límit de comercialització entre 6-8 dies d'emmagatzemament a 5 ºC, depenent del MS. No obstant, l'aplicació d'antioxidants va reduir de manera significativa la fermesa del fruit comparat amb el control. La combinació d'aquestos antioxidants amb 10 g L-1 de CaCl2 va permetre mantenir la fermesa en el mateix rang que les mostres control. En un treball posterior, l'aplicació de 1-metilciclopropeno (1-MCP) va permetre processar caqui emmagatzemat 45 dies a 1 ºC amb una bona fermesa comercial i a més, el tractament antioxidant (10 g L-1 CA + 10 g L-1 CaCl2) va aconseguir un límit de comercialització del producte tallat de 9 dies a 5 ºC. L'avaluació de diferents atmosferes controlades en combinació amb tractaments antioxidants (AA o CA), com a pas previ a l'envasament en atmosfera modificada (MAP) del caqui 'Rojo Brillante, va mostrar com a més efectiva en el control del pardetjament enzimàtic l'atmosfera composta per 5 kPa O2 (balanç N2). Aquesta atmosfera va mantenir la qualitat visual del caqui tallat dins del límit de comercialització durant 7-9 dies a 5 ºC. Per contra, l'aplicació d'altes concentracions de CO2 (10 ó 20 kPa) va donar lloc a un pardetjament en certes zones de la polpa, el qual és conegut com 'internal flesh browning'. Estudis posteriors van confirmar l'efecte beneficiós de l'envasament de caqui tallat i tractat amb solució antioxidant (CA-CaCl2) en una MAP activa de 5 kPa O2 millorant la qualitat visual de la fruita front a l'aplicació de una MAP passiva. El desenvolupament de recobriments comestibles amb capacitat antioxidant es va realitzar mitjançant la incorporació d'antioxidants (CA-CaCl2) en formulacions a base de proteïna de sèrum làctic (WPI), proteïna de soia (SPI), hidroxipropilmetilcel-lulosa (HPMC) i pectina. Tots els recobriments van ser efectius controlant el pardetjament enzimàtic del caqui tallat. No obstant, les mostres recobertes amb HPMC i pectina van ser millor avaluades visualment que la resta de tractaments. En general, el processat, l'aplicació d'antioxidants, l'envasament en atmosferes controlades i els distints recobriments comestibles estudiats, si bé no van mostrar un efecte clar en els paràmetres de la qualitat nutricional avaluats, no van tindre un efecte negatiu en els mateixos. Per altra banda, els fruits recol¿lectats a final de temporada van tenir major activitat antioxidant i contingut en
Sanchís Soler, E. (2016). Effect of processing on the physicochemical, sensory, nutritional and microbiological quality of fresh-cut 'Rojo Brillante' persimmon [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62588
TESIS

During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and ��-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-�� (TNF-��), and interleukin-1�� (IL-1��) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and ��-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-��, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1�� concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 ��g/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions.
Graduation date: 2003

Oxidative stress is the major driving force behind the aging process and many age-related diseases. However, direct experimental evidence of whether antioxidants, such as ascorbate (AA) and lipoic acid (LA) can slow the progression of aging process and/or reduce risks of developing degenerative disease is largely absent. This suggests a better understanding of the precise mechanism of how dietary micronutrient affect parameters of involved in cellular redox balance and aging are warranted. In this dissertation, young and old rats were used as our model to understand potential pro-oxidant events that contribute to increases in oxidative stress in various tissues and how antioxidants such as ascorbate and lipoic acid influence these events. Our major findings are that the age-related impairment of mitochondria and increased deposition of iron contribute significantly to heighten levels of oxidative stress, as evidenced by the resultant increases in the rates of oxidant appearance and in the levels of oxidative damage to DNA, lipids and proteins. We find that AA and LA strongly protected against transition metal-ion dependent increases in oxidative stress. AA effectively inhibited transition metal-mediated lipide peroxidation in human plasma. LA in its reduced form effectively binds iron and copper in a redox inactive manner and reversed chronically elevated levels of iron in the brain without removing enzyme bound transition metal ions. LA also significantly attenuated the age-related increase in oxidative stress associated with mitochondrial decay in the heart, as evidenced by the improvements in AA levels and glutathione redox status. The declines in tissue GSH levels in aged rats were strongly associated with the diminished γ-GCL activity (in parallel with decreased expression of the catalytic and modulatory subunits), and lowered Nrf2 expression and binding to ARE sequence in rat liver. Remarkably, all these events were effectively reversed by the administration of LA, modulating the parameters to return to the observed in young animals. The implications of this work open new avenues not only for further understanding of the aging process but also for possible strategies in its modulation by the micronutrients.
Graduation date: 2004

The primary goal of my studies was to elucidate the mechanisms for the well-recognized interaction between two nutrients, vitamins E and K. The outcomes from my studies assess mechanisms for adverse effects of vitamin E and provide novel information on mechanisms for vitamin K homeostasis. These findings will provide information relevant for assessing optimal intakes of vitamins E and K. This dissertation presents studies aimed at evaluating three different mechanisms by which vitamin K status could be decreased by increases in whole body vitamin E concentrations in rats supplemented with vitamin E by subcutaneous injections (100 mg α-tocopherol (α-T)/ kg body weight per day), the model system developed in the Traber lab. The tested mechanisms by which vitamin E leads to reduced vitamin K status were: 1) increasing vitamin K metabolism, 2) decreasing menaquinone-4 (MK-4) synthesis from dietary phylloquinone (PK) and 3) potentiating vitamin K excretion through xenobiotic pathways. Two approaches were undertaken to evaluate the hypothesis that vitamin E increases vitamin K metabolism. In Aim 1.1, the in vitro omega-hydroxylation of vitamin K by human cytochrome P450 CYP4F2 (expressed in insect microsomes) was tested because CYP4F2 is considered the limiting step in the catabolism of both vitamins. Chapter 2 shows that CYP4F2 more rapidly hydroxylated vitamin K compared with vitamin E. Moreover, vitamin E did not stimulate vitamin K metabolism in vitro. Thus, it is unlikely vitamin E stimulates vitamin K metabolism in vivo by direct interaction with the CYP4F2 enzyme-substrate complex. In Aim 1.2, the in vivo urinary and biliary excretion of vitamin K metabolites was investigated. Chapter 3 shows that α-T-injected rats significantly increased urinary excretion of vitamin E catabolites, but no increases in urinary vitamin K catabolites were found. Chapter 4 shows that α-T-injected rats increased biliary excretion of 5C-aglycone, a major vitamin K catabolite shared by MK-4 and PK. However, the overall in vivo excretion of vitamin K catabolites was not changed when urinary excretion was also taken into account. Aim 2 evaluated the hypothesis that α-T interferes with the conversion of PK to MK-4 because α-T and PK have similar side-chains. In Aim 2.1, conversion of PK or MN to MK-4 was tested in vivo. Rats were fed semi-purified diets containing equimolar concentrations of either PK or MN for 10 days, then α-T injections were undertaken. Chapter 3 shows that extra-hepatic tissues from α-T injected rats contained significantly lower MK-4 concentrations irrespective of whether the rats were fed PK or MN. These findings show that if vitamin E is interfering with the metabolic mechanism of MK-4 synthesis, then it is not specific to the cleavage of PK's side chain. In Aim 2.2, conversion of deuterium-labeled PK (d₄-PK) to d₄-MK-4 was used to evaluate the extra-hepatic tissue uptake of d₄-PK in α-T-injected rats. Rats were fed semi-purified diets containing equimolar concentrations of d₄-PK similar to my previous study for 10 days then α-T injections were undertaken for 7 days. Chapter 5 shows that total (labeled and unlabeled) vitamin K concentrations decreased in extra-hepatic tissues from α-T injected rats fed d₄-PK. Both d₄-MK-4 and d₄-PK concentrations decreased, suggesting that MK-4 concentrations were dependent upon those of d₄-PK. These findings suggest that PK, and not MN, is the primary substrate for MK-4 synthesis in extra-hepatic tissues. Moreover, both d₄-MK-4 and d₄-PK decreased in α-T-injected rats demonstrating that vitamin E's untoward effect on vitamin K status is likely a mechanism that is shared by both vitamin K forms and not specific to MK-4 synthesis. Recycling of vitamin K from the epoxide was not examined in this study and interference with the recycling mechanism for either PK or MK-4 in α-T injected rats has not been examined. Vitamin E metabolism is greatly increased in α-T-injected rats by increasing various xenobiotic pathways. Thus, vitamin K status was hypothesized to decrease in α-T-injected rats as a result of the up-regulation of these pathways. As shown in Aim 1, urinary vitamin K metabolite excretion was not increased in α-T-injected rats. In Aim 3.1, the biliary excretion of vitamins E and K were examined to evaluate whether the increased expression in biliary transporters, such as MDR1, led to increased vitamin K and E excretion via the bile. Chapter 4 shows that α-T increased in bile over the week of vitamin E injections and α-CEHC was the major vitamin E form excreted in bile. Although biliary PK secretion was unchanged and biliary MK-4 was undetectable, increased excretion of a major catabolite of both PK and MK-4, 5C-aglycone, was observed. In Aim, 3.2, the gene expression of enzymes and transporters in liver and extra-hepatic tissues as mechanisms involved in regulating their concentrations in these tissues was assessed. In Chapters 3 and 5, increased expression of biliary transporters were observed, one of which is known to bind the vitamin K intermediate MN as its substrate. It is possible other vitamin K catabolites, in addition to 5C-and 7C-aglycone, may have been excreted that were unaccounted for, e.g. MN or vitamin K epoxide metabolites. In summary, my studies have shown vitamin K status is decreased in α-T-injected rats because PK and MK-4 concentrations are decreased in many extra-hepatic tissues. Although metabolism of vitamin K was not stimulated in response to α-T injections, increased excretion of a vitamin K catabolite was measured in the bile; however it may not account for all of the vitamin K loss observed in tissues. Alternatively, transport of PK and MN to extra-hepatic tissues or MK-4 recycling may have been inhibited in response to vitamin E. Further studies are needed to distinguish between these mechanisms.
Graduation date: 2013

碩士
國立成功大學
化學系
88
In this study, we have employed gel filtration chromatograph，fluorescence spectroscopy，SDS-PAGE electrophoresis and the measurement of glutathione content of lens and the assay of α-crystallin chaperone-like function to investigate the effect of 5% ascorbate on galactosemic rat lenses. It was found that both the flurorescence intensities of 1-anilino-8-naphthalene sulphonate(ANS)/α-crystallin and of tryptophan residues of α-crystallin increased with the increase of galacosemic time with or without the influence of 5% ascorbate，indicating 5% ascorbate in not able to prevent the structural changes of α-crystallin during galactosemic period. The chaperone-like activity of α-crystallin from galactosemic lens with or without the effect of ascorbate showed the same activity toward dithiothretol induced insulin B-chain aggregation. The measurement of lens glutathione content showed that the amount dropped rapidly for the first week for both experimental and control groups，from about 10ug/mg to 1ug/mg；however the glutathione content of experimental group was maintained at average about 0.9ug/mg after first week，whereas it dropped gradually for the control group. This indicates thatascorbate has the effect to prevent the oxidation of glutathione after first week in galactosemic time. The gel filtration and SDS-PAGE electrophoresis analyses showed that (i). the amounts of bH-andg-crystallin descreased gradually，whereas the amount of α-crystallin almost did not change for both experimental and control group；(ii) the band of 32 kDa disappeared after 3 weeks for the control group，whereas it was still observed for the experimental group after 3 weeks. Based on this study，It is concluded that 5% ascorbate does shows the ability to prevent the oxidation of glutathione after first week，however it shows no effect to prevent the formation of cataract during galactosemic experiment. It is becoming interesting to characterize as to what percentage of ascorbate is enough to prevent the glutathione from oxidation and whether higher glutaione content is a factor of preventing the formation of cataract caused by galactose.

This study was designed to evaluate the effect of glucose on plasma pyridoxal 5'- phosphate (PLP) concentration. The objective was to determine whether there was a negative relationship between glucose ingestion and plasma PLP concentration and to evaluate the possible mechanism of decreased PLP after acute glucose ingestion. Seven healthy subjects (three males and four females) completed the oral glucose tolerance test (OGTT) on three separate occasions over a period of three weeks. Each week, subjects ingested the assigned solutions (a water solution with artificial sweetener equivalent to 25g glucose, a 25g glucose or a 75g glucose load) in a randomized order. Plasma PLP, pyridoxal (PL), 4-pyridoxic acid (4-PA), pyridoxine (PN), glucose, insulin, alkaline phosphatase (AP) activity and red blood cell PLP concentrations were measured at 0 (fasting) (TO), 1 (T1), 2 (T2) and 3 (T3) hours. The mean vitamin B-6 intake based on two 3-day dietary records was 1.57 ± 0.34 mg/day. All subjects had normal glucose tolerance. There were gender differences among the three solutions. Both the water solution and the 75g glucose load showed a significant decrease in the mean plasma PLP concentration was observed at T3 for males and at T2 for females (p<0.05). An overall mean decrease of 20% (9nmol/L) and 15% (7 nmol/L) was observed for males and females, respectively, after the 75g glucose load. The 25g glucose load resulted in a lower decrease in the mean plasma PLP concentration at each time point compared with the 75g glucose load, but no significant difference was found in the level of decrease between the two glucose loads. Both genders had a non-significant increase in the mean plasma PL and PN concentrations for the three solutions. Mean plasma 4-PA concentration was decreased at T1 with the three solutions. There was no significant change in the plasma AP activity at any time points after the three solutions. In addition, no significant increase in mean red blood cell PLP concentration was observed at all time points after the three solutions. This study found a negative relationship between glucose ingestion and plasma PLP concentration. However, it did not provide clear evidence for the hypothesized mechanism of the decreased plasma PLP concentration after acute glucose load. Further studies are required to determine the mechanism by which glucose decreases plasma PLP concentration.
Graduation date: 2000

Magister Scientiae (Medical Bioscience) - MSc(MBS)
Maternal smoking is known to cause serious health risks to the unborn child. Recent studies implicate nicotine as the causative factor. Maternal nicotine exposure during pregnancy and lactation interferes with foetal and neonatal lung growth and development,rendering the lung more susceptible to damage and diseases. Therefore, the aim of this study was to investigate: 1) the effect of maternal exposure to nicotine (1mg/kg BW/day) during all phases of lung development: 2) and vitamin C supplementation (0.5mg/kg BW/day) to prevent the adverse effects of maternal nicotine exposure on lung development in the offspring. This is based on studies in our laboratories which suggested that nicotine reduces the blood and tissue vitamin C content of the mother,thereby rendering the neonate more susceptible to oxidation damage. The chief motivation of this study was to establish whether an anti-oxidant, such as vitamin C, can be administered to smoking pregnant and lactating mothers in order to combat the deleterious effects of nicotine on the lung development of their offspring. It was found that although maternal nicotine exposure had no significant effect on the growth parameters of the offspring, it did have an effect on the development of the lung, compromising the ability of the lung to act as an organ of gaseous exchange. There was a decrease in the surface area available for gas exchange. The change occurred after the lung reached maturation and resembled microscopic emphysema. Vitamin C supplementation was unable to fully protect the neonatal lung against the adverse effects of maternal nicotine exposure; it however partially protected the neonatal lung against structural deterioration. Supplementation with vitamin C definitely offers possibilities as a prophylactic to combat the detrimental influence of maternal nicotine-exposure on foetal and postnatal lung development.

碩士
國立中興大學
食品暨應用生物科技學系所
99
Overall abstract: Lung cancer, a highly metastatic cancers and difficultly diagnosis in an early stage, is one of the most common cause of death for cancer patients death in worldwide. Metastasizing cells must first disseminate from the primary tumor, invade the surrounding tissue, intravasate and extravasate the circulatory system, arrest, initiate angiogenesis and colonize distant site. Therefore, development of novel therapeutic strategy for treatment lung cancer is important. Vitamin C in combination with vitamin K3 (vit CK3) has been shown to inhibit tumor growth and metastasis in vivo, but the mechanism of action is poorly understood. In the first part thesis of, C57BL/6 mice were implanted (s.c.) with Lewis lung carcinoma (LLC) for 9 days before injection (i.p.) with low- (100 mg vit C/kg + 1 mg vit K3/kg) and high- dose (1000 mg vit C/kg + 10 mg vit K3/kg) vit CK3 twice a week for additional 28 days. As expected, vit CK3 or cisplatin (6 mg /kg, as positive control) significantly and dose-dependently inhibited tumor growth and lung metastasis in LLC-bearing mice. Vit CK3 restored the body weight of tumor-bearing mice to the level of tumor-free mice. Vit CK3 significantly decreased activities of plasma metalloproteinase (MMP)-2, -9 and urokinase plasminogen activator (uPA). In lung tissues, Vit CK3 1) increased protein expression of tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, non-metastatic protein 23 homolog 1 (nm23-H1) and plasminogen activator inhibitor-1 (PAI-1); 2) reduced protein expression of MMP-2 and MMP-9; 3) inhibited the proliferating cell nuclear antigen (PCNA). These results demonstrate that vitamin CK3 inhibits primary tumor growth and exhibits anti-metastastic potential in vivo through attenuated tumor invasion and proliferation. Platiunm complexes have been shown to inhibit the tumor growth in animals and in human. Among these platinum complexs, cisplatin was the first found to be anti-cancer drugs, but produced strong nephrotoxicity. In the second part of this thesis, we further investigated the role of vit C on nephrotoxicity and oxdative damage caused by cisplatin and the additive effect of vit C in combination with cisplatin. Similarly, we used the same animal model from first part of thesis. Herein, C57BL/6 mice were implanted (s.c.) with Lewis lung carcinoma (LLC) for 9 days before injection (i.p.) with low (200 mg/kg), high-dose (1000 mg/kg) vitamin C in the present or absence of cisplatin (5 mg/kg) twice a week for additional 28 days. Results revealed that vitamin C or cisplatin alone significantly inhibited tumor growth, whereas the inhibitory effect of vitamin C in combination with cisplatin did not exhibit synergistic effect. In addition, we found that vitamin C in combination with cisplatin reduce the nephrotoxicity and oxidative damage caused by cisplatin, as evidenced by decreasing blood urea nitrogen (BUN) and creatinine in plasma and decreasing TBARS, carbonyls and GSH/GSSG ratio in liver and kidney tissues. In summary, we demonstrate that vitamin CK3 inhibits primary tumor growth and exhibits anti-metastastic potential in vivo in first part of thesis, and the results suggest that this effect is related to attenuation of tumor invasion and proliferation. Besides, in second part of this thesis, we demonstrate that vitamin C in combination with cisplatin inhibits primary tumor growth, and reduced the nephrotoxicity and oxidative damage caused by cisplatin in vivo. chapter 1: Vitamin C in combination with vitamin K3 (vit CK3) has been shown to inhibit tumor growth and lung metastasis in vivo, but the mechanism of action is poorly understood. Herein , C57BL/6 mice were implanted (s.c.) with Lewis lung carcinoma (LLC) for 9 d before injection (i.p.) with low- (100 mg vit C/kg + 1 mg vit K3/kg), high-dose (1000 mg vit C/kg + 10 mg vit K3/kg) vit CK3 twice a week for additional 28 days. As expected, vit CK3 or cisplatin (6 mg /kg, as positive control) significantly and dose-dependently inhibited tumor growth and lung metastasis in LLC-bearing mice. Vit CK3 restored the body weight of tumor-bearing mice to the level of tumor-free mice. Vit CK3 significantly decreased activities of plasma metalloproteinase (MMP)-2, -9 and urokinase plasminogen activator (uPA). In lung tissues, Vit CK3 1) increased protein expression of tissue inhibitor of metalloproteinase-1 (TIMP-1, TIMP-2), non-metastatic protein 23 homolog 1 (nm23-H1) and plasminogen activator inhibitor-1 (PAI-1); 2) reduced protein expression of MMP-2 and MMP-9; 3) inhibited the proliferating cell nuclear antigen (PCNA). These results demonstrate that vitamin CK3 inhibits primary tumor growth and exhibits anti-metastastic potential in vivo through attenuated tumor invasion and proliferation. chapter 2: Platiunm complexes have been shown to inhibit the tumor growth in animals and in human. Among these platinum complexs, cisplatin was the first found to be anti-cancer drugs, but produced strong nephrotoxicity. Vitamin C (vit C), an important water soluble vitamin and antioxidant, has been shown to protect cell membranes and DNA integrity against free radicals attack to avoid the progress of chronic disease, such as cardiovascular disease and cancer. However, little is known whether vit C enhanced the anticancer effect and reduces the nephrotoxicity and oxidative damage caused by cisplatin in tumor-xenografted mice. Herein, C57BL/6 mice were implanted (s.c.) with Lewis lung carcinoma (LLC) for 9 days before administration (i.p.) with low (200 mg/kg), high-dose (1000 mg/kg) vit C in the present or absence of cisplatin (5 mg/kg) twice a week for additional 28 days. Results reveal that vit C or cisplatin alone significantly inhibited tumor growth whereas vit C in combination with cisplatin did not exhibit synergistic effect. In addition, vit C ameliorated the nephrotoxicity and oxidative damage caused by cisplatin, as evidenced by decreased blood urea nitrogen (BUN) and creatinine in plasma and decreased TBARS, carbonyls and GSH/GSSG ratios in liver and kidney tissues. In summary, the present study demonstrates that vit C inhibits tumor growth and reduces the nephrotoxicity and oxidative damage in LLC-bearing mice induced by cisplatin.

Previous studies suggest that vitamin B-6 supplementation can alter fuel metabolism during exercise and plasma amino acid levels at rest. To examine the effect of vitamin B-6 supplementation on plasma fuel substrates and amino acid levels during exercise, five trained males (age: 29±7; V0₂ max: 54.7±6.2 ml/kg/min) performed two separate submaximal, endurance, exercise tests on a cycle ergometer. Subjects were exercised to exhaustion at 74.5±7.8% V0₂ max in a fasted condition on the seventh morning of two separate nine day controlled diet periods. The first exercise test (T1) occurred following a control or non-supplemented (NS) diet (i.e. 1.9 mg B-6/day), and the second exercise test (T2) occurred following a vitamin B-6 supplemented (S) diet (i.e. 1.9 mg B-6/day + 20 mg PN/day). Blood was drawn pre, during (i.e. 60 minutes into exercise), post, and post-60 minutes of exercise, and plasma was analyzed for glucose, lactic acid, glycerol, free fatty acids (FFA), and amino acids. Expired air was collected for three minutes at 10 minute intervals during both tests. Although not statistically different, there were observed trends for higher mean lactate levels and lower mean glycerol and FFA levels in T2 (S) compared to T1 (NS). Mean lactate, glycerol, and FFA concentrations all changed statistically significantly over time in both exercise tests. Mean plasma tyrosine levels were significantly lower (p = 0.007) at post-60 minutes of exercise and mean plasma methionine levels were significantly lower (p = 0.03) at post-exercise in T2 relative to T1. Of the 13 amino acids quantitated, only alanine and histidine concentrations changed significantly over time. Although not statistically significant, mean respiratory exchange (R) values tended to be higher in T2 compared to T1. Mean oxygen consumption values were significantly higher (p = 0.02) during the first 10 minutes of exercise and at multiple later time points showed a trend for being higher in T2 compared to T1. No statistically significant differences were observed in subjects' performance times to exhaustion between T1 (1:35:49; hr:min:sec) and T2 (1:31:56). These results indicate that vitamin B-6 supplementation can potentially alter fuel metabolism and plasma amino acid levels during exhaustive endurance exercise; however, not to such a degree that one's endurance capacity is affected.
Graduation date: 1995

Previous studies have found that smoking may have a negative effect on vitamin B-6 indices and have demonstrated a possible association between smoking and depressed plasma pyridoxal-5'-phosphate (PLP) concentration. Individuals with plasma PLP values below the adequate level of 30 nmoles/L might benefit from consumption of vitamin B-6 supplements, but no data are available on vitamin B-6 status in smokers consuming a controlled vitamin B-6 intake and receiving a vitamin B-6 supplement. The objectives of this research were to assess vitamin B-6 status in smokers as compared to non-smokers receiving a controlled diet and to evaluate the effect of an oral vitamin B-6 supplementation in these subjects. The vitamin B-6 (B-6) status of 5 (four males / one female) smokers (S) and 4 (three males / one female) non-smokers (NS) was assessed. A constant diet was fed for 20 days and provided 1.95 mg of B-6 or 1.65 mg of B-6 for males and females, respectively. For the last 10 days, an additional 2-mg of pyridoxine (PN) was given daily. Blood samples were collected on days 1.7, 11.14 and 21; and 24 hour urine samples were collected daily. Urinary 4-pyridoxic acid (4-PA) and total B-6 (UB6) excretion, plasma B-6 vitamers (PLP, PN, pyridoxal and 4-PA) and red blood cell PLP (RBC PLP) concentrations, as well as plasma alkaline phosphatase activity (APA) were determined. Mean plasma PLP, 4-PA, and RBC PLP concentrations were significantly lower (P [less than or equal to] 0.05) at all time points in S compared to NS. With a daily supplement of 2-mg vitamin B-6, the mean plasma PLP concentration of S increased 85.8% but was 48.5% lower than that of NS consuming 1.65-1.95 mg/d of B-6. Mean plasma pyridoxal concentrations were not different between S and NS before and after supplementation. Excretion of 4-PA was not significantly different between S and NS, but the mean values of 4-PA excretion were consistently greater in NS compared to that of S throughout the 20-day study. The percent of ingested B-6 excreted as 4-PA for the S and NS was 38 and 49 in the non-supplemented period, and 47 and 53 in the supplemented period, respectively, indicating that non-smokers excreted more 4-PA than smokers. However, the difference in 4-PA excretion between S and NS was not significantly different both before and after supplementation (P>0.05). In addition, there was no significant difference between S and NS for plasma PN concentration, AP, and UB6 excretion for both periods. Results suggested an adverse effect of smoking on B-6 metabolism, thus an increased requirement of vitamin B-6 in smokers. A 2-mg PN supplement was sufficient to bring the concentration of plasma PLP in smokers to the level suggested as adequate, but it didn't bring it to the level of non-smokers.
Graduation date: 1999

碩士
靜宜大學
食品營養研究所
94
Hyperglycemia-induced platelet activation may play an important role on thrombogenesis in diabetic complications. Therefore, the purpose of this study was to investigate the effect of vitamin C and vitamin E supplements on platelets hyperactivity. Forty type 2 DM patients were randomly assigned into four experimental groups in this double-blinded study. Treatment groups were placebo, vitamin C (500 mg/d), vitamin E (400 mg α-TA/d) and vitamin C+E, respectively. After 8 weeks’ supplement, plasma concentration of vitamin C, vitamin E, MDA and total antioxidant status (TAS) were determined, and markers of activated platelet (PAC-1, CD62P) were analyzed by flow cytometry. The results of this study showed that plasma concentration of vitamin C and vitamin E was increased significantly by vitamin supplements. Plasma TAS tended to be ameliorated by vitamin supplements, however, plasma MDA concentration was decreased significantly in C and C+E groups, when compared to placebo group. The expression of PAC-1 was decreased by vitamin E supplement, and CD62P expression was impaired in vitamin C group. In conclusion, vitamin C and vitamin E supplements may be beneficial for type 2 DM patients in the prevention of thrombotic complications.

The present study investigated whether vitamin E supplementation reduced oxidative stress in erythrocytes and improved vitamin E status in patients undergoing hemodialysis (HD). Plasma and erythrocyte α-tocopherol, plasma ascorbic acid, and iron status were determined in 11 regular HD patients prior to and post-dialysis, before and during oral supplementation of vitamin E, 400 IU daily for two months. HD patients were categorized into two groups according to their plasma ascorbic acid levels. We found that only the vitamin C sufficient group (>40 μM, Group I) had reliable measurements of erythrocyte α-tocopherol concentrations before vitamin E supplementation. In Group I prior to dialysis, erythrocyte α-tocopherol concentrations increased in response to vitamin E supplementation from 6.7 ± 0.7 μmol/L packed cells to 9.8 ± 0.6 (μmol/L packed cells (p<0.04). Moreover, there was a positive correlation (pGraduation date: 2003