Academic literature on the topic 'Antidiabetic evaluation'

The purpose of this review is to summarize the available antidiabetic medicinal plants in the Kingdom of Saudi Arabia with its phytoconstituents and toxicological findings supporting by the latest literature. Required data about medicinal plants having antidiabetic activities and growing in the Kingdom of Saudi Arabia were searched/collected from the online databases including Wiley, Google, PubMed, Google Scholar, ScienceDirect, and Scopus. Keywords used in search are in vivo antidiabetic activities, flora of Saudi Arabia, active ingredients, toxicological evaluations, and medicinal plants. A total of 50 plant species belonging to 27 families were found in the flora of Saudi Arabia. Dominant family was found Lamiaceae with 5 species (highest) followed by Moraceae with 4 species. β-Amyrin, β-sitosterol, stigmasterol, oleanolic acid, ursolic acid, rutin, chlorogenic acid, quercetin, and kaempferol are the very common bioactive constituents of these selected plant species. This paper has presented a list of antidiabetic plants used in the treatment of diabetes mellitus. Bioactive antidiabetic phytoconstituents which showed that these plants have hypoglycemic effects and highly recommended for further pharmacological purposes and to isolate/identify antidiabetes mellitus (anti-DM) active agents also need to investigate the side effects of active ingredients.

The present study aimed to formulate, develop, and evaluate a herbal tea granule preparation composed of Hibiscus rosa-sinensis (Java), Zingiber officinale (Ginger), Elettaria cardamomum (Cardamon), and Stevia rebaudiana (Stevia), targeting potential antidiabetic effects. Each of these herbs has been traditionally recognized for its antidiabetic properties, and their combination was hypothesized to exert enhanced synergistic effects. A total of nine formulation, differing in the properties of herbal components. Hibiscus rosa-sinensis has also been widely used in herbal teas and beverages. Several studies conducted using animal models have evaluated the antidiabetic and antioxidant potential of the Hibiscus flower petals and leaves. The optimized formulation was subjected to comprehensive evaluation, including phytochemical profiling, antioxidant assays, antidiabetic and organoleptic analysis (taste, color, aroma, and overall acceptability) and assessment of physical parameters (moisture content, bulk density, and particle size). 

This research aims to create and assess polyherbal anti-diabetic capsules using medicinal plants with anti-diabetic properties. The formulation process involves carefully choosing botanical extracts with antidiabetic properties, verifying their bioactive compounds, and blending them to form a polyherbal blend with maximum antidiabetic potential while ensuring safety.Micro Crystalline Cellulose is used in encapsulating a polyherbal mix for stability, release, and patient convenience. Capsule dosage form is recommended for improved treatment adherence. Efficiency is assessed through in vitro studies on enzymes involved in glucose metabolism and their inhibitory effect.The results of this study offer a viable natural option for managing diabetes by providing important insights into the composition of polyherbal antidiabetic capsules. Several botanical extracts with complimentary modes of action have the potential to be combined, offering a comprehensive strategy to address the complex nature of diabetes mellitus. Nevertheless, more clinical studies including diabetes patients are necessary to confirm the long-term advantages, safety, and effectiveness of the capsules. The creation of polyherbal antidiabetic capsules may present novel approaches to the management of diabetes, enhancing glycaemic control and elevating the standard of living for those with the condition.

Antimicrobial peptides, as an important member of the innate immune system, have various biological activities in addition to antimicrobial activity. There are some AMPs with antidiabetic activity, especially those isolated from amphibians. These peptides can induce insulin release via different mechanisms based on peptide type. In this review study, we collected all reported AMPs with antidiabetic activity. We also analyze the sequence and structure of these peptides for evaluation of sequence and structure effect on their antidiabetic activity. Based on this review, the biggest peptide family with antidiabetic activity is temporins with nine antidiabetic peptides. Frogs are the most abundant source of antidiabetic peptides. Bioinformatics analysis showed that an increase of positive net charge and a decrease of hydrophobicity can improve the insulinotropic effect of peptides. Peptides with higher positive net charge and Boman index showed higher activity. Based on this review article, AMPs with antidiabetic activity, especially those isolated from amphibians, can be used as novel antidiabetic drug for type 2 diabetes disease. So, amphibians are potential sources for active peptides which merit further evaluation as novel insulin secretagogues. However, strategy for the increase of stability and positive activity as well as the decrease of negative side effects must be considered.

Lilium nepalense, a temperate medicinal plant, is used as a diuretic, antipyretic, tonic, flavoring agent, and heart pain treatment. This research aimed to evaluate the in vitro antioxidant and antidiabetic activities of the methanol, dichloromethane (DCM), and hexane fractions, and in vivo cytotoxic activities of the crude extracts of the bulb. The antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, antidiabetic activity by α-glucosidase inhibitory assay, and cytotoxic activity in terms of LC50 (median lethality concentration) by Brine shrimp assay. The DCM fraction showed the strongest antioxidant activity (IC50=134.99±9.75 µg/mL) and highest antidiabetic activity (IC50=182.01±20.50 µg/mL) than other fractions. Similarly, the DCM fraction had the highest total phenolic contents (243.97±33.78 mg of gallic acid equivalent per gram dry weight) and highest flavonoid contents (7.68±0.85 mg of quercetin equivalent per gram dry weight) than other fractions. Moreover, the crude extract of the bulb was not found to be cytotoxic to the Brine shrimp nauplii (LC50=3.83 mg/mL). It is the first report to date describing the antioxidant, antidiabetic, and cytotoxic properties of L. nepalense. This study concludes that the DCM fraction of the bulb could be used as an antioxidant and antidiabetic agent for therapeutic purposes; however, further identification and characterization of bioactive compounds responsible for the antioxidant, antidiabetic, and cytotoxicity is required for further validation.

Infection with the protozoan parasite Trypanosoma cruzi causes human Chagas disease. Benznidazole (BNZ) and nifurtimox are the current drugs for the treatment; however, they induce severe adverse side effects in patients; therefore, there is a need to improve the treatment effectiveness and efficiency of these drugs for its safer use. Background/Objective: Glyburide, glipizide, and gliquidone, hypoglycemic drugs for diabetes treatment, were previously predicted to bind to dihydrofolate reductase-thymidylate synthase from T. cruzi by in silico docking analysis; they also showed antiproliferative effects against T. cruzi epimastigotes, the stage of the insect vector. In the present study, the potential parasiticidal effect of these antidiabetic drugs was tested in monotherapy and bi-therapy with BNZ in human cells in vitro and in animals. Methods: Evaluation was performed in (a) a model of in vitro infection of T. cruzi trypomastigotes using human fibroblasts as host cells and (b) in mice infected with T. cruzi. Results: The antidiabetic drugs in monotherapy showed antiparasitic effects in preventing infection progression (trypomastigotes release), with an IC50 of 8.4–14.3 µM in comparison to that of BNZ (0.26 µM) in vitro. However, in bi-therapy, the presence of just 0.5 or 1 µM of the antidiabetics decreased the BNZ IC50 by 5–10 times to 0.03–0.05 µM. Remarkably, the antidiabetic drugs in monotherapy decreased the infection in mice by 40–60% in a similar extent to BNZ (80%). In addition, the combination of BNZ plus antidiabetics perturbed the antioxidant metabolites in epimastigotes. Conclusions: These results identified antidiabetics as potential drugs in combination therapy with BNZ to treat T. cruzi infection.

ABSTRACT Nanotechnology is emerging as a promising approach in the development of novel therapeutic strategies. Nanoparticles, due to their unique physicochemical properties and small size, have the potential to improve the delivery of therapeutic agents, enhance their bioavailability, and increase their efficacy. Among various types of nanoparticles, strontium nanoparticles have gained attention due to their potential antidiabetic activity and cytotoxic effects against cancer cells. Mimosa pudica, also known as “Sensitive Plant” or “Touch-Me-Not,” is a medicinal plant known for its diverse pharmacological activities, including antidiabetic and anticancer properties. Recent research has focused on the synthesis of strontium nanoparticles by using Mimosa pudica as a green and sustainable approach. These nanoparticles have shown promising results in terms of their antidiabetic activity and cytotoxic effects against cancer cells. Thus, in this study, the antidiabetic effect was studied using the alpha-amylase inhibitor assay, and the cytotoxic effect was studied using the brine shrimp lethality assay. In these assays, increasing concentration of Mimosa pudica-mediated strontium nanoparticles exhibited increasing antidiabetic and cytotoxic effects, which was similar to the standard used, which is acarbose. Hence, this can be used as a novel antidiabetic and cytotoxic agent in the future.

Syzygium cordatum is a medicinal plant indigenous to South Africa and Mozambique, commonly used to treat stomach aches, diabetes, respiratory problems and tuberculosis. In spite of the folklore use, adequate scientific data to credit its widespread traditional use is lacking. The objectives of this study were: to evaluate and validate scientifically the successful therapeutic claims by traditional medicine practitioners that Syzygium cordatum is effective in treating diarrhoea and diabetes<br>to determine the effects of the plant extract on gastrointestinal transit of a charcoal meal in mice<br>to determine the effects on castor oilinduced intestinal fluid accumulation<br>to determine the safety profile of the plant by carrying out acute toxicology study and to carry out preliminary screening of the active compounds present in the plant using standard phytochemical analytical procedures. The aqueous leaf extract of Syzygium cordatum (3.125 -50mg/kg, p.o) significantly reduced the faecal output caused by castor oil (0.7ml). All the doses used, reduced faecal output from 100% produced by castor oil to between 40 and 61%. S.cordatum (6.25 &ndash<br>50mg/kg, p.o) significantly and in a dose dependent manner, delayed the onset of castor oil-induced diarrhoea.

Fármacos pouco solúveis em água são um dos maiores desafios encontrados em formulação de comprimidos, uma vez que, se não adequadamente formulados, podem apresentar problemas de dissolução e de biodisponibilidade. O presente trabalho teve como objetivo produzir comprimidos de glibenclamida 5 mg (hipoglicemiante oral pouco solúvel) utilizando diferentes processos visando a melhoria da dissolução do fármaco e comparar a liberação in vitro (perfil de dissolução) das formulações entre si, bem como em relação ao medicamento referência no Brasil, Daonil&#174;. Foram obtidas 19 formulações por compressão direta empregando dispersão sólida, complexação com ciclodextrina ou micronização do fármaco. Os comprimidos foram analisados quanto ao aspecto, peso médio, dureza, friabilidade, teor e eficiência de dissolução. Os resultados indicaram que, dentre os processos estudados, a utilização de complexos glibenclamida-&#946;-ciclodextrina e glibenclamida micronizada, promoveram uma melhora da dissolução do fármaco. O superdesintegrante Explocel&#174; promoveu significativa melhoria no perfil de dissolução em todas as formulações em que estava presente. A utilização do complexo glibenclamida-&#946;-ciclodextrina com o Explocel&#174; apresentou perfil de dissolução estatisticamente semelhante ao Daonil&#174;, além de atender aos demais requisitos físico-químicos.<br>Slightly soluble drugs are one of the largest challenges found in tablet formulation, once, if not appropriately formulated, they can present dissolution and bioavailability problems. The present work had as objective to produce 5 mg glibenclamide (practically insoluble hipoglicemic drug) tablets using different processes which aim at enhancing drug dissolution and to compare the in vitro release (dissolution profile) of these formulations with each other as well as with the reference medicine in Brazil, Daonil&#174;. 19 diferent formulations were obtained through direct compression using solid dispersion, cyclodextrin complexion or micronization of the drug. The tablets were also analyzed in relation to aspect, medium weight, hardness, friability, assay and dissolution eficiency. The results indicated that, among the studied processes, an enhancement of the dissolution rate of the drug have arisen from the use of the glibenclamide-&#946;-cyclodextrin complex and the micronized glibenclamide. The disintegrant Explocel&#174; promoted enhancement in the dissolution rate in all the formulations in which it was present. The use of the glibenclamide-&#946;-cyclodextrin complex with Explocel&#174; have presented the best dissolution profile, statistically similar to Daonil&#174;, besides accomplishing the other physico-chemical requirements.

Tese de doutoramento, Farmácia (Química Farmacêutica e Terapêutica), Universidade de Lisboa, Faculdade de Farmácia, 2011<br>Coreopsis tinctoria Nutt. is a small aromatic annual and widely distributed plant that belongs to the Asteraceae family. Its use in traditional medicine has been described as early as the XVII century in China, where its decoction has been used for diarrhoea. Other medicinal properties have been added by North American Indians and include treatment of internal pains, bleeding, to strengthen blood and as an emetic. In Portugal, an infusion of the flowering tops has been described to have antidiabetic proprieties, applied to diabetes type 2 treatment. There are some published phytochemical studies on the genus Coreopsis but the information on this species chemical composition, until recently, was scarce. Flavonoids of chalcone, aurone and flavanone structure have been described in C. tinctoria flowering tops although there was no available information on the chemical constitution of bioactive extracts. Flavonoids are polyphenols well known for their antioxidant and cytoprotective activity that have also been shown to act at several levels in the glucose metabolism, which may be of relevance in the prevention and treatment of diabetes and its complications. Thus the present study aimed to: i) search for new antidiabetic lead molecules able to reduce both glycemia and tissue damage; ii) chemically characterize the bioactive extracts, and; iii) study the antidiabetic profile of extracts and metabolites of C. tinctoria as this species lacked any kind of pharmacological and toxicological data. The aqueous extract of C. tinctoria flowering tops was prepared following the traditional recipe. Fractionation by chromatography followed, and three major compounds were isolated and identified by spectroscopic methodologies. Other thirteen phenolic compounds were identified by HPLC-DAD-MS/MS. Through this technique, reproducible methods for quantitative analysis of the main compounds in bioactive extracts were also developed. Further on, to evaluate whether C. tinctoria had a beneficial effect on diabetes some in vivo assays were performed. In order to test for acute antihyhyperglycemic activity, the aqueous extract was administered to normal (euglycemic) rats at different concentrations and blood glucose levels were monitored by an oral glucose tolerance test. None of concentrations tested have shown significant lowering blood glucose effect compared to control group. In order to understand other possible glucose lowering effects, a streptozotocininduced glucose-intolerant rat model was developed. C. tinctoria aqueous extract (500 mg/Kg) was then daily administrated during three weeks which resulted in significant recovery of glucose tolerance. The active extract was quantified in terms of its main compound, the chalcone marein. As means to determine whether flavonoids were the bioactive compounds, a flavonoid-rich AcOEt fraction (125 mg/Kg), with the same marein content as the bioactive aqueous extract, was prepared and administered to the glucose-intolerant model. Results indicated glucose tolerance regain after only two weeks of treatment, an effect that was maintained over the remaining experimental period. Moreover, lipase values normalized indicating re-establishment of pancreatic function. In addition, the oral treatment with either C. tinctoria aqueous extract or AcOEt fraction caused no hepatotoxicity. Regarding cytotoxicity, C. tinctoria extracts were tested in vitro, using a pancreatic mouse insulinoma cell line (MIN6). Cell viability tests were performed and no cytotoxic effects were observed at the concentrations tested (up to 3 mg/mL). Possible insulin-secretagogue action of the bioactive C. tinctoria extracts was evaluated in two ways: i) using MIN6 cells disposed as monolayers through static incubation method or; ii) in a more sensitive model, using MIN6 cells disposed in three dimensional structures (pseudoislets) using a perifusion technique. Both yielded data that seems to indicate that C. tinctoria extracts do not act increasing insulin secretion. C. tinctoria extracts and pure compounds (marein and flavanomarein), known to be good antioxidants, were then tested for their potential protective effects in MIN6 cells challenged with pro-oxidant tert-Butyl-Hydroperoxide (tBHP) or cytokines. Results indicate that C. tinctoria extracts and pure compounds are effective cytoprotectors, which seems to be due to inhibition of the apoptotic pathway, and not through a decrease on superoxide radical production. Overall, these results support the conclusion that phenolic compounds present in C. tinctoria flowering tops extracts promote recovery of pancreatic function and glucose intolerance possibly by an anti-apoptotic mechanism of injured pancreas, suggesting C. tinctoria traditional use in diabetes therapy<br>Coreopsis tinctoria Nutt. é uma pequena planta aromática anual, amplamente distribuída, pertencente à família das Asteraceas. Trata-se de uma planta cujo primeiro registo de utilização na medicina tradicional, data do século XVII na China, onde a sua decocção tem sido aplicada para a diarreia. Outras aplicações medicinais foram entretanto desenvolvidas por outros povos, nomeadamente, pelos Índios da América do Norte para o tratamento de dores, hemorragias, para fortalecimento do sangue e como um emético. Em Portugal, a infusão dos ápices florais de Coreopsis tinctoria, também conhecida como Estrelas-do-Egipto, foi descrita como tendo propriedades antidiabéticas, passível de ser aplicada no tratamento da diabetes do tipo dois. Existem já alguns estudos publicados na área da fitoquímica, aplicados ao género Coreopsis. No entanto, até muito recentemente, o conhecimento da composição química da espécie Coreopsis tinctoria era escasso. Flavonóides com estrutura do tipo chalcona, aurona e flavanona foram já descritos nos ápices florais desta espécie, apesar de não existir nenhuma informação sobre a constituição química de extractos bioactivos. Os flavonóides são compostos fenólicos bem conhecidos pela sua actividade antioxidante e citoprotectora, tendo também demonstrado efeitos a vários níveis no metabolismo da glucose, o que pode ser relevante na prevenção e tratamento da diabetes e das complicações macro e micro vasculares associadas a esta patologia. Tendo em conta todos estes factores, os principais objectivos deste projecto foram: i) a pesquisa de novas moléculas com potencial antidiabético capazes de reduzir tanto a glicémia como a danificação de tecidos, ii) caracterizar quimicamente os extractos bioactivos, e, iii) desenvolver um estudo do perfil antidiabético dos extractos e metabolitos presentes na Coreopsis tinctoria, na medida em que sobre esta espécie não havia até então, nenhum tipo de dados farmacológicos nem informação relativa à sua possível toxicidade. O extracto aquoso dos ápices florais da Coreopsis tinctoria foi preparado de acordo com a utilização tradicional em Portugal. Seguiu-se o fraccionamento cromatográfico, do qual se obtiveram três compostos maioritários, que foram isolados e identificados recorrendo a metodologias espectroscópicas. Outros treze compostos fenólicos foram identificados por HPLC-DAD-MS/MS. Através desta técnica, foram também desenvolvidos métodos para a análise quantitativa dos principais compostos presentes nos extractos bioactivos. No seguimento dos objectivos deste projecto, de forma a avaliar os potenciais efeitos benéficos da infusão (extracto aquoso) dos ápices florais da Coreopsis tinctoria na diabetes, procedeu-se ao estudo farmacológico, desenvolvendo alguns ensaios in vivo. Para testar a actividade antihiperglicémica aguda, administraram-se diferentes concentrações do extracto aquoso a ratos normais (euglicémicos) e, seguidamente, monitorizaram-se os níveis de glucose no sangue através do teste oral de tolerância à glucose. Nenhuma das concentrações testadas revelou um efeito significativo de diminuição dos valores de glucose no sangue comparando com o grupo controlo. Para compreender a possibilidade de outros efeitos estarem envolvidos na capacidade desta planta afectar os níveis de glucose no sangue, foi desenvolvido, em ratos Wistar, um modelo de intolerância à glucose (40 mg/Kg de estreptozotocina), na medida em que esta é característica numa situação de pré-diabetes e pode constituir por si só um risco no desenvolvimento de doenças cardiovasculares. O extracto aquoso (500 mg/Kg) foi então administrado diariamente e por sonda intragástrica durante três semanas a ratos Wistar intolerantes à glucose, tendo resultado na recuperação dos níveis de glicémia. O composto identificado como maioritário, a chalcona mareina, foi quantificado no extracto activo. Como forma de determinar se os flavonóides eram os compostos bioactivos no extracto aquoso, uma fracção de acetato de etilo, rica em flavonóides mas com igual conteúdo em mareina, foi preparada e administrada (125 mg/Kg) aos ratos Wistar intolerantes à glucose. Os resultados revelaram, logo ao fim de duas semanas de.tratamento, uma normalização das curvas de glicémia, efeito que se manteve até ao final do período experimental. Adicionalmente observou-se uma recuperação da função pancreática medida pelos níveis de lipase plasmática. É de salientar, que os animais tratados com ambos, extracto aquoso e fracção de Acetato de Etilo, não apresentaram sinais de hepatotoxicidade, após três semanas de tratamento. Relativamente à citotoxicidade, os referidos extractos foram testados in vitro usando uma linha celular pancreática derivada de insulinoma de murganho (MIN6). Testes de viabilidade celular foram efectuados não revelando efeitos de toxicidade nas concentrações testadas (até 3 mg/mL). Uma possível acção insulino-secretagoga dos extractos bioactivos da Coreopsis tinctoria foi investigada de duas formas: i) usando células MIN6 dispostas em monocamada, através de um método de incubação estática ou; ii) utilizando um modelo mais sensível, usando células MIN6 dispostas em estruturas tridimensionais, também designadas por “pseudo-ilhéus”, recorrendo a uma técnica de perfusão. Ambas aparentam indicar que os extractos bioactivos de Coreopsis tinctoria não estimulam a secreção insulínica. Os extractos da Coreopsis tinctoria assim como os seus constituintes maioritários, mareina e flavanomareina, conhecidos por apresentarem actividade antioxidante, foram testados com o objectivo de avaliar o seu potencial efeito protector em células MIN6 expostas ao pro-oxidante, terc-Butil-Hidroperóxido (tBHP,) ou a um conjunto de citocinas. Os resultados revelaram, que tanto os extractos da Coreopsis tinctoria, assim como a mareina e a flavanomareina são efectivamente protectores, o que parece ser devido a uma inibição da via apoptótica e não à diminuição da produção do radical superóxido. Em conclusão, estes resultados tendem a indicar, que os compostos fenólicos presentes nos extractos dos ápices florais da Coreopsis tinctoria, promovem a recuperação da função pancreática e consequentemente revertem a situação de intolerância à glucose possivelmente através de um mecanismo anti-apoptótico no tecido pancreático danificado, o que não contraria o uso tradicional da Coreopsis tinctoria na terapia da diabetes.<br>Fundação para a Ciência e a Tecnologia(FCT)

碩士<br>高雄醫學大學<br>臨床藥學研究所<br>98<br>Background: Several studies have suggested an association between specific antidiabetic medications and cancer morbidity. This study was aimed at the assessment of association between different antidiabetic medications and cancer risks by using Taiwan National Health Insurance claims database. Methods: We used the Longitudinal Health Insurance Database 2005 (LHID 2005) (1997-2007) to conduct a nested matched case-control study. Among the study population of type 2 diabetic patients, we identified 2,687 ptaients who had an incident malignancy. 5,369 controls were matched with the corresponding cases for age, sex, duration of follow-up and index year. Multiple logistic regression was used and ORs were estimated for assessing association between antidiabetic medications and cancer risks. Results: Dual therapy of metformin and Sulfonylureas was significant associated with higher cancer risks (adjusted OR 1.13, 95%CI 1.02-1.25). Among Sulfonylureas, glyburide (glibenclamide) treatment was associated with a significant higher cancer risks (adjusted OR 1.15, 95%CI 1.01-1.31). There was no significant association between treatment with meglitinides, insulin, thiazolidinediones, or acarbose and cancer risk. And long-term treatments also showed no significant association with cancer risk. Conclusion: The results of this study show that only Sulfonylureas has a trend to increase cancer risks whereas other antidiabetic medications do not. Dual therapy with metformin and Sulfonylureas shows significant higher cancer risk. And the duration of antidiabetic medication exposure didn’t show well association with cancer risks. Further studies are needed to confirm the results.

Tese de Doutoramento em Ciências - Área de Conhecimento em Biologia<br>Type 2 diabetes mellitus is a disease that is assuming epidemic proportions worldwide. The interest for the medicinal plants with antidiabetic properties has increased with the demand for new active compounds with minor side effects than the currently available drugs. In the present work, two species of the genus Salvia (S. fruticosa and S. officinalis) that enjoy of antidiabetic reputation were studied with regard to their mechanisms of action. In order to study the effects of S. fruticosa tea on plasma glucose and on the well known diabetes-induced expression of intestinal Na+/glucose-cotransporter (SGLT1), diabetes was induced with streptozotocin (STZ) in rats (chapter 2). We verified that, in diabetic rats, although sage tea treatment did not decrease blood glucose levels to near physiological values, it allowed their stabilisation, contrarily to its control group, where hyperglycaemia aggravated during the experiment. Sage tea treatment also reduced the induction of SGLT1 expression on the apical membrane of enterocytes by the diabetic condition. In healthy rats, S. fruticosa tea did not interfere neither with the expression of SGLT1, nor with the levels of blood glucose, indicating that it does not reveal hypoglycaemic properties and does not affect normal levels of SGLT1 expression. In a subsequent study using dietary manipulation of SGLT1 expression (chapter 3), we aimed to confirm in vivo the S. fruticosa tea effects on the SGLT1 glucose transporter, when mechanisms of induction of its expression are present. A low carbohydrate (LC) diet reduced the expression of rat glucose transporter. With the reintroduction of the diet rich in carbohydrates (HC diet), SGLT1 levels on the apical membrane (BBM) of enterocytes were re-established. When sage tea (instead of water) was given at the same time that HC diet was reintroduced, the recovery of SGLT1 levels on BBM was not fully achieved, indicating that S. fruticosa interferes with mechanism of increased expression of SGLT1. We also observed that rosmarinic acid (the most abundant phenolic compound of Salvia spp.) given as an aqueous solution (instead of water) attained the same results than sage tea, indicating that this seems to be the active principle in the extract. With this work we also aimed to understand the mechanism(s) that underlies the effect of S. fruticosa on SGLT1 expression. We found that the expression of protein kinase C (PKC) and of heat shock protein 70 (Hsp70) were affected by sage tea in a similar manner to the one obtained for SGLT1. These proteins have been reported to be involved in the translocation of SGLT1 to the plasma membrane, which aware for future studies on those signalling pathways in order to understand the molecular mechanisms. Taking into account that the previous observations on the expression of SGLT1 could indirectly result from a decrease in glucose available in the intestinal lumen induced by sage tea, due to inhibition of digestive enzymes, we further evaluated the effects of sage water extracts (teas), as well as some of their individual compounds on the activity of the digestive enzyme α-amylase (chapter 4). The different sage teas did not inhibited in vitro the α-amylase activity, which was only attained in some extent by the individual compound luteolin-7-glucoside (L7G). Therefore, the result of sage on the SGLT1 expression seems not to be due to secondary effects on the carbohydrate digestion. In chapter 4, we also studied some effects of L7G and ursolic acid (UA) in rats. Both sage compounds reduced postprandial glucose levels in the plasma, as well as improved the lipid profile of the animals. However, while L7G mechanisms of glycaemic control seem to involve a slight inhibition of carbohydrate digestion, UA seems to act on the stimulation of liver glycogen deposition. Both compounds showed beneficial effects on plasma cholesterol levels and (UA mainly) on lipoproteins, thus demonstrating potential for reducing the risk of cardiovascular complications. In the chapter 5, we performed some studies regarding the antidiabetic activities of S. officinalis tea. Previous results showed that S. officinalis tea treatment diminished fasting plasma glucose levels of non-diabetic mice, and did not produce effects on plasma glucose clearance mechanisms, which suggested effects on hepatic gluconeogenesis. Taking this into account, a study with STZ-diabetic and non-diabetic rats treated with S. officinalis tea was performed. Subsequently hepatocytes were isolated and their response to pancreatic hormones – insulin and glucagon – was studied. We verified that in hepatocytes isolated from non-diabetic rats, sage tea increased glucose consumption and decreased gluconeogenesis. S. officinalis essential oil increased hepatocyte insulin sensitivity and contributed to gluconeogenesis inhibition. Also in chapter 5 are results of a pilot trial with S. officinalis tea treatment during four weeks in human volunteers. Tea consumption was particularly beneficial on the control of lipid profile, as well as on their antioxidant defences, indicating beneficial properties namely on the prevention of cardiovascular diseases. We concluded with this work that the antidiabetic properties of S. fruticosa seem to be at the intestinal level, particularly on the reduction of the diet/diabetes-induced increases in SGLT1 expression. Both Hsp70 and PKC seem to be involved in this effect, and the active principle of this tea seems to be rosmarinic acid. On the other hand S. officinalis is more effective on the regulation of hepatic gluconeogenesis and on control of lipid profile. In both cases the drinking of sage teas can be considered safe.<br>Diabetes mellitus tipo 2 é uma doença que está a assumir proporções epidémicas a nível mundial. O interesse pelas plantas medicinais com propriedades antidiabéticas tem aumentado bem como a procura de novos compostos activos com efeitos secundários menores do que os dos fármacos actualmente utilizados. No presente trabalho foram estudadas duas espécies do género Salvia (S. fruticosa Mill. e S. officinalis L.) que gozam de reputação como antidiabéticas, no que respeita aos seus mecanismos de acção. Em primeiro lugar, com o intuito de estudar os efeitos do chá de S. fruticosa na glucose plasmática e no aumento característico da expressão do transportador de glucose (SGLT1) numa situação de diabetes, esta foi induzida com estreptozotocina em ratos (capítulo 2). Verificou-se que em ratos diabéticos, embora o tratamento com o chá não tivesse diminuído os valores da glucose no sangue para valores próximos dos fisiológicos, permitiu a sua estabilização, contrariamente ao respectivo grupo controlo, no qual a hiperglicémia se agravou ao longo do ensaio. O tratamento com chá também reduziu o característico aumento da expressão do transportador de glucose (SGLT1) ao nível da membrana apical (BBM) dos enterócitos, associado à situação de diabetes. Em ratos não-diabéticos o chá de S. fruticosa não interferiu com a expressão do SGLT1, nem com os níveis de glucose no sangue, indicando que este chá não revela propriedades hipoglicemiantes, nem altera valores basais de expressão do SGLT1. Num estudo posterior, de modo a confirmar in vivo os efeitos do chá de S. fruticosa sobre o SGLT1, recorreu-se à manipulação da dieta para a indução da expressão do SGLT1 (capítulo 3). Uma dieta pobre em hidratos de carbono (LC) reduziu a expressão dos transportadores de glucose dos ratos. Com a reintrodução da dieta rica em hidratos de carbono (HC) os níveis normais de SGLT1 foram retomados na BBM dos enterócitos. Contudo, quando administrado o chá de S. fruticosa aquando da reintrodução da dieta HC, a normalização dos níveis de SGLT1 na BBM foi bastante inibida, indicando uma vez mais que o chá interfere no mecanismo do aumento da expressão do SGLT1. Também se observou que o ácido rosmarínico (composto fenólico maioritário de espécies de Salvia) administrado em solução aquosa produziu efeitos semelhantes aos do chá, mas de uma forma mais significativa, indicando-o como um princípio activo do extracto. Com este trabalho procurou-se também perceber o(s) mecanismo(s) que estaria na base do efeito da S. fruticosa sobre o SGLT1. Verificou-se que a expressão da proteína cinase C (PKC) e da de choque térmico (Hsp70) foram afectadas de forma semelhante ao SGLT1. Uma vez que estas proteínas parecem estar envolvidas na translocação do SGLT1 para a membrana, mais estudos são necessários para compreender efeitos nessas vias de sinalização. Atendendo ao facto de os resultados obtidos sobre a expressão do SGLT1 poderem indirectamente resultar de uma diminuição da glucose no lúmen, induzida pelo chá devido à inibição de enzimas digestivas, avaliamos posteriormente os efeitos dos chás, bem como de alguns dos seus compostos individuais na actividade da enzima digestiva α-amilase (capítulo 4). Os diferentes chás de salva não inibiram in vitro a actividade da α-amilase, e apenas a luteolina-7-glicosídeo (L7G) o conseguiu em alguma extensão. Desta forma, o efeito do chá sobre a expressão do SGLT1 não parece ser devido a efeitos secundários sobre a digestão dos hidratos de carbono. No capítulo 4 também foram estudados alguns efeitos da L7G e do ácido ursólico (UA) em ratos. Ambos os compostos de salva diminuíram os níveis de glucose pós-prandial no plasma e melhoraram o perfil lipídico dos animais. Contudo, enquanto que os mecanismos de controlo da glicemia da L7G poderão envolver uma moderada inibição da digestão dos hidratos de carbono, o UA parece actuar na estimulação da deposição de glicogénio no fígado. Ambos os compostos tiveram efeitos benéficos sobre os níveis de colesterol no plasma, e o UA em particular sobre as lipoproteínas, mostrando assim potencial para reduzir o risco de complicações cardiovasculares. No capítulo 5 são apresentados estudos relativos à avaliação de actividades antidiabéticas do chá de S. officinalis. Resultados anteriores mostraram que o chá de S. officinalis diminuía os níveis de glucose plasmática em jejum de ratinhos não-diabéticos, não produzindo efeitos sobre os mecanismos de remoção da glucose plasmática, o que sugeriu efeitos sobre a gluconeogénese. Atendendo a estes resultados, foi realizado um estudo com ratos diabéticos e não-diabéticos tratados com chá de S. officinalis. Posteriormente foram isolados hepatócitos e estudada a sua resposta às hormonas insulina e glucagon. Em hepatócitos isolados de ratos não-diabéticos, o chá administrado in vivo aumentou o consumo de glucose in vitro e reduziu a gluconeogénese. O óleo essencial de S. officinalis aumentou a sensibilidade dos hepatócitos à insulina e contribuiu para a inibição da gluconeogénese. Ainda no capítulo 5 são apresentados resultados de um estudo piloto com voluntários humanos tratados com chá de S. officinalis. O chá apresentou sobretudo efeitos benéficos no controlo do perfil lipídico, bem como nas defesas antioxidantes, indicando propriedades benéficas em particular na prevenção de complicações cardiovasculares. Com este trabalho conclui-se que as propriedades antidiabéticas da S. fruticosa se situam sobretudo ao nível do intestino, em particular na redução da indução da expressão do SGLT1. Ambas as proteínas Hsp70 e PKC parecem estar envolvidas neste efeito e o princípio activo deste chá parece ser o ácido rosmarínico. Por outro lado, a S. officinalis é mais eficaz na regulação da gluconeogénese e no controlo do perfil lipídico. Em ambos os casos, a toma do chá de salva pode ser considerada segura.<br>Fundação para a Ciência e a Tecnologia (FCT) - POCI/AGR/62040/2004.

碩士<br>中國醫藥大學<br>營養學系碩士班<br>101<br>A novel approach for treatment of type 2 diabetes is the use of gut hormone glucagon-like peptide-1 (GLP-1), which possesses multi-functions such as the stimulation of insulin secretin and the blood glucose homeostasis. GLP-1 is a polypeptide that is rapidly inactivated by dipeptidyl peptidase IV (DPP-IV). DPP-IV is a postproline-cleaving enzyme with the specificity for removing X-proline or X-alanine dipeptides from the N-terminus of polypeptides. Therefore, the peptides with Pro or Ala as the penultimate amino acid residue of N-terminus would be efficient DPP-IV inhibitors to elongate the half life of endogenous GLP-1. It is well-known that gelatin is rich in Pro, Ala, Hyp, while that of warm-water fish skin has higher contents of the three amino acid residues than cold-water fish. The objective of this study is to utilize commercial proteases flavourzyme to hydrolyze gelatin extracted from halibut, tilapia and milkfish skin, and to produce the DPP-IV inhibitory peptides and determine their antidiabetic activity in animal in vivo experiments. The results were shown as follows: 1. The contents of Pro, Ala, Hyp from halibut, tilapia, milkfish skin gelatin were 32.18, 37.6, 38.55 mole/100 mole amino acid residues. The warm-water fish (tilapia and milkfish) skin gelatin showed higher contents of the three amino acid residues than the cold-water fish (halibut). 2. Halibut, tilapia and milkfish skin gelatins were hydrolyzed with Fla at various enzyme/substrate (E/S) ratio (1, 3, 5%) for 4 h. The DHs and DPP-IV inhibitory activity of the gelatin hydrolysates obtained by Fla hydrolysis increased with the increment of E/S ratio. When the hydrolysis process was done with the E/S ratio of 5% for 6 and 8 h, the both warm-water fish skin gelatin hydrolysates showed the greater DPP-IV inhibition rates of 45-48% as compared to the cold-water fish. The hydrolysates from both warm-water fish skin gelatin with E/S of 5% and 6-h hydrolysis were used for ultrafiltration. 3. The peptides within <1 kDa fraction from tilapia skin gelatin hydrolysates had the greatest DPP-IV inhibition rate of 51.91% as compared to those within the other two high-molecular-weight fractions (1-2.5 kDa and >2.5 kDa). The <1 kDa fraction was then used to evaluate its in vivo antidiabetic effect by the animal experiment, and the peptides in this fraction were comprised of Pro and Ala of 11.22, 16.39 mole/100 mole amino acid residues, respectively. 4. The oral administration with medial dose (750 mg/kg BW) of tilapia fish skin gelatin hydrolysate could significantly (p<0.05) decrease the plasma DPP-IV activity for 31.74%, and slightly but insignificantly (p>0.05) increase plasma GLP-1 for 35.4% in diabetic (DM) rats. Also, the hydrolysate effectively increased the plasma insulin concentration for 121% (p<0.05) as compared to DM rats and improve the blood glucose control. The tilapia fish skin gelatin hydrolysate is useful for the therapy or prevention of type 2 diabetes. Tilapia fish skin gelatin hydrolysate can be develop a new functional food and to increase the economic values of fish processing byproducts.

Pasireotide LAR (PAS) has a safety profile similar to first-generation somatostatin in analogues (SSA), except for a higher frequency of hyperglycaemia-related adverse events. However, consensus on the best management of PAS-induced hyperglycaemia in acromegalic patients has still to be defined. The current study aim at investigating the effects of long-term PAS treatment on glucose metabolism, besides GH and IGF-I control, by evaluating the clinical management of hyperglycemia adverse events in acromegalic patients followed in two Italian referral Centers, participating to the PAOLA study, a randomized, Phase III study assessing the efficacy and safety of PAS compared with patients with inadequately controlled acromegaly during first-generation SSA. Moreover, the role of metabolic parameters (weight, BMI, fasting glucose and HbA1c levels) and markers of disease activity (GH, IGF-I, duration of PAS treatment) were investigated as potential predictors of hyperglycemia development. A total of 31 patients (16 F/15 M, mean age 47.6 years) entered the present study, including 18 randomized to PAS (group 1), and 13 to continued treatment with octreotide LAR 30 mg or lanreotide Autogel 120 mg (group 2) for six months (core study). All patients in group 2 who remained uncontrolled at 6 months had the opportunity to switch to PAS in the extension phase. In all patients, fasting glucose and HbA1c were evaluated every 6 months, according to the study protocols. At baseline, pre-existing diabetes mellitus (DM) was found in five patients (27.7%) in group 1 and one (7.7%) in group 2 (p=0.34), whereas pre-existing prediabetes, defined as impaired glucose tolerance (IGT) or impaired fasting glucose (IFG), was seen in one patients (5.5%, IGT) in group 1 and in three patients (23.1%, 2 IGT, 1 IFG) in group 2 (p=0.34). Patients were treated with PAS for a mean time of 34 months (6-67 months). Hyperglycemia-related adverse events were reported in 15 patients (83.3%) in group 1, occurring after a mean time of 5 months (1-16 months). One patient required treatment discontinuation because of diabetes adverse event. Four out five patients with DM at baseline (80%) reported worsening of hyperglycemia during PAS treatment. One patient with IGT at baseline (100%) developed overt DM. Six (50%) and four (33.3%) patients with normal glucose tolerance (NGT) at baseline developed IFG and DM, respectively, during PAS treatment. In group 2, three (23%) patients reported hyperglycemia-related adverse events during the core phase (during first-generation SSA therapy), after a mean time of two months. Particularly, overt DM occurred in two patients (15.3%) with baseline NGT and in one patient (7.7%) with IGT at baseline. All cases were of mild severity, defined as grade 1. During the extension phase, nine patients (69.2%) reported hyperglycemia-related adverse events after a mean time of seven months (2-17 months) from the beginning of PAS treatment. One diabetic patient (33.3%) reported worsening hyperglycemia. Among patients with NGT at baseline, three (16.6%) developed pre-diabetes (2 IFG, 1 IGT), and two patients (15.3%) developed overt DM during PAS treatment. All cases reported in group 1 and 2 were of mild-to-moderate severity, defined as grade 2-3, and were judged to be related to PAS. The risk to develop hyperglycemia correlated neither with baseline BMI, weight, GH, IGF-I, glucose and HbA1c levels, or duration of PAS treatment (p=0.41). Similarly, glucose status did not significantly correlate with biochemical control at the last follow-up (p=0.66). At study entry, three patients (16.6%) in group 1 and one patient (7.7%) in group 2 were already treated with antidiabetic drugs. In group 1, starting of new antidiabetic treatment was required in eight patients (44.4 %) throughout the study, and metformin (MET) was the drug of choice in all these patients. Four (50%) out eight patients did not control glucose and HbA1c levels despite MET monotherapy, needing further therapies. In fact, MET was associated with DPP-4 inhibitor in one patient (25%), GLP-1 agonist in two patients (50%), and GLP-1 agonist and glargine insulin in one patient (25%) to control hyperglycemia. Two patients previously treated with antidiabetic drugs (1 patient with MET plus glargine insulin, and 1 patient with glargine insulin monotherapy) needed a dose adjustment to control hyperglycemia. In group 2, one patient (7.7%) started MET during the core phase. During the extension phase, starting of new antidiabetic treatment was required in seven patients (53.8%), and MET was the drug of choice in all these patients. Three (42.8%) out seven patients did not control glucose and HbA1c levels despite MET monotherapy, requiring further therapies. MET was associated with DPP-4 inhibitor in one patient (33.3%), GLP-1 agonist in two patients (33.3%), and GLP-1 agonist and detemir insulin in one patient (33.3%) to control hyperglycemia. The results of the present study confirm the known negative effect of PAS on glucose metabolism, however treatment intensification with DPP4 inhibitor and GLP-1 agonist resulted in good glycemic control in most patients. Further studies are needed to deeply evaluate the mechanism of PAS-induced hyperglycemia in acromegalyc patients, investigating the effect of PAS on insulin secretion and hepatic/peripheral insulin sensitivity.

The overall objective of this study was to evaluate the impact of cardiovascular safety concerns on the utilization of the thiazolidinediones (TZDs), pioglitazone and rosiglitazone, and other oral antidiabetic drugs. In May 2007, a meta-analysis was published that found a potential increased risk of myocardial infarction (MI) associated with TZDs, particularly with rosiglitazone. A two-year retrospective study of patients diagnosed with type 2 diabetes (ICD9 250.xx) using prescription and medical databases from the Scott & White Health System (SWHS) was conducted. Patients aged 18 or older who were continuously enrolled with SWHS from 2006 to 2008 and had high adherence (Medication Adherence Ratio ≥80%) for either pioglitazone or rosiglitazone during the pre-safety warning period (May 2006- April 2007) were included. Patients were followed through the post-safety warning period (May 2007 - October 2008) or occurrence of event (discontinuation of index TZD drug). Patients who discontinued their index TZD drug by April 2008 were identified if they had a prescription filled for a new oral antidiabetic drugs (OADs), and followed until October 2008 or occurrence of event (discontinuation of new OAD). Cox proportional hazards models were used to assess the rate of and time to discontinuation of index TZD and new OAD with adjustment of age, gender and Charlson Comorbidity Index (CCI). A total of 531 patients (58 percent male; mean age [SD] = 61 [9.1] years) were included in the final analysis, 255 and 276 patients in the rosiglitazone and pioglitazone groups, respectively. The rate of discontinuation for the pioglitazone and rosiglitazone groups began to separate within 90 days of the index event (meta-analysis published in May 2007). In the pioglitazone group, the rate of discontinuation was significantly lower than in the rosiglitazone group ( HR = 0.56; 95% CI = 0.47, 0.67). A total of 21 patients did not experience discontinuation of their index medication. Among patients receiving a new OAD after discontinuing their index TZD (N = 95 rosiglitazone and N = 33 pioglitazone patients), there was no statistical significant in the rate of discontinuing their new OAD between the rosiglitazone and pioglitazone groups (HR = 0.98; 95% CI = 0.61, 1.59). However, patients who received metformin/sulfonylurea combinations had a lower rate of discontinuation compared to patients who received sulfonylureas (HR = 0.38; 94% CI = 0.21, 0.66). The analysis showed the cardiovascular safety concern of TZDs had a significant impact on the utilization of oral antidiabetic drug utilization.<br>text

碩士<br>國立嘉義大學<br>食品科學暨生物藥學研究所<br>99<br>Diabetes mellitus (DM) is a metabolic disorder disease of insulin secretion. Chronic hyperglycemia may lead to numerous biological complications, such as hypertension and other cardiovascular diseases. The critical enzymes for the breakdown of complex carbohydrates are pancreatic α-amylase and intestinal α-glucosidase. The inhibition of both enzyme activities can delay postprandial hyperglycemia via decreasing meal-derived glucose absorption. Moreover, inhibition of hypertension-linked angiotensin converting enzyme (ACE) was targeted as a potential approach for modulation of DM-linked hypertension. The objective of this study was to evaluate the inhibitory effects of extracts from the edible mushroom Pleurotus citrinopileatus on α-amylase, α-glucosidase and ACE using in vitro models. Extracts of P. citrinopileatus were further fractioned to investigate the effects of the active components responsible for the regulation of blood sugar and blood pressure. The results showed that the antioxidative effect and inhibitory effects on α-amylase, α-glucosidase and ACE of the cold water extracts (PCC-24H) from P. citrinopileatus were significantly higher than those from hot water extracts (PCH-1H and PCH-2H). The antioxidative and inhibitory effects were also assayed after fractionation of cold water extract of P. citrinopileatus into different molecular weight fractions (PCC-&amp;lt;1 kDa, PCC-1-3.5 kDa, PCC-3.5-10 kDa and PCC-> 10 kDa) by ultrafiltration. The results showed that the antioxidative effect of PCC-&amp;lt;1 kDa, PCC-1-3.5 kDa, and PCC-3.5-10 kDa fractions was significantly higher than that of PCC->10 kDa fraction. The antioxidative activity was correlated well with phenolic contents. The inhibitory effects of PCC->10 kDa fraction on α-amylase, α-glucosidase, and ACE were significantly higher than those of the other three fractions. PCC->10 kDa exerted a higher inhibition on α-amylase than PCC-24H, which the inhibition of PCC-24H and PCC->10 kDa were 1/13.4 to 1/2.7 relative to that of acarbose. However, the inhibitory ability of PCC->10 kDa on α-glucosidase (IC50 = 0.5 mg/mL) was significantly higher than acarbose (IC50 = 1.7 mg/mL). Protein or total sugar content of extracts might response for the inhibition. Kinetic data revealed that PCC->10 kDa followed a non-competitive inhibiton on α-glucosidase activity. Cold water extract of P. citrinopileatus was precipitated with 100% ammonium sulfate or 75% ethanol to obtain protein (PCC-Pr)-rich or polysaccharide (PCC-Ps)-rich fractions, respectively. The regulation of blood sugar and blood pressure of PCC-Pr and PCC-Ps were assessed as the earlier in vitro methods. Since the antioxidative activity of PCC-Pr on α-amylase, α-glucosidase, and ACE were significantly higher than PCC-Ps, protein was considered to be the major inhibitory components. This is the first in vitro study to investigate extracts from P. citrinopileatus on the activities of antihyperglycemice and antihypertensive related enzymes. This study demonstrated that the correlation between protein content of the extract and the hypoglycemic and antihypertensive effects. In the future, further purification of the active ingredients for the application on the hypoglycemic and antihypertensive effects deserved studied.

Sulfonamides are appropriate ligands for the preparation of coordination compounds with biological activity, as they possess bactericidal, antiviral, antidiabetic, and diuretic properties and some sulfonamide compounds are under clinical evaluation for cancer treatment. Metal complexes provide highly versatile platforms for drug design. Considering the biological potential of the quinoline nucleus, but also of the sulfonamide scaffold (especially antimicrobial), as well as that of the quinoline- sulfonamide combination we have decided to combine the two pharmacophore fragments. And at last, the complexation with divalent metals - M2+ (M2+: Zn2+, Cu2+, Co2+ and Cd2+) will bring complementary biological activity given by the cation with the final goal of achieving improved biological activity and better pharmacokinetic properties. The synthesized molecules were characterized by HRMS and NMR spectroscopy. The compounds were preliminary screened for their antibacterial and antifungal activity and the obtained results are very promising.v