Gotowa bibliografia na temat „Free radical scavanger”

Ethanolic extract of propolis (EEP) was tested as a protective agent against gamma irradiation in mice. The mice were exposed to 6 Gy gamma irradiation from a 60Co source, and were treated intraperitoneally with EEP, administered before and after their irradiation. While the non-treated mice expired within 12 weeks, the mice that received a series of EEP treatments survived the irradiation, and their leucocyte count as well as their spleens’ plaque-forming activity returned to normal. It is suggested that an antioxidant and a free radical scavanger in the EEP are responsible for the radiation protective effect of the extract of this natural product.

The cocoa seeds of the Gumbrih-Bali region are a natural commodity with great potential for development or processing by local communities. The purpose of this research is to provide information about the antioxidant potential contained in cocoa seeds. Testing the antioxidant capacity in this study uses the Uv-Vis spectrophotometry method at 517 nm wavelengths. Free radical scavanger is measured with control absorption and samples was analyzed with regression curve. The research results proved that the antioxidant (AAI) in the n-butanol fraction show result very strong ability of 4.64 compared to the 0.42 ethyl acetate fraction and 0.46 n-hexane fraction. These results prove that the potential chemical content of cocoa seeds is high in polar solvents (n-butanol fractions) such as flavonoid compounds. Furthermore, this research will be used as a basis for developing natural herbal ingredients such as cocoa which can be consumed in the community to prevent degenerative diseases.

Spices show potential health benefits as they possess antioxidant activity. The study was to determine the effect of cooking on the antioxidant activity of some selected spices. The total phenol content of five spices (Onion, Garlic, Ginger, Turmeric, and Basil) was determined at different heating periods (1h and 2 h) at 100⁰c. Although these dietary spice are resistant to thermal denaturation, interestingly, in the case of onion shows reduction in all the tested activities and others shows different variation in all the activity. Total antioxidant activity was measured, based on the reduction of Mo (VI) to Mo (v) by the extract and subsequent formation of green phosphate / Mo (v) complex at acid pH. The extracts were found to have different level of antioxidant properties at different heating time. Considering all the activities, turmeric has good activity amongst the five spice materials screened for their antioxidant properties. Lowest activity was found in onion. In addition to the antioxidant activity of these spices, the total phenolic compounds, flavonoids were measured in the extracts. A correlation between the antioxidant activity and total phenolic content was observed.

9041 Background: Cisplatin is one of the most frequently used chemotherapy agents. The main dose-limiting toxicity for its use is hearing-loss, present in 40–100% of patients. To date, no treatment has proven efficacy in preventing or reducing cisplatin acoustic damage. Fosfomycin, acting as a free-radical scavanger, has shown to reduce cisplatin-induced ototoxicity and nephrotoxicity in animal models, without affecting its antineoplastic activity. This trial evaluated the effect of fosfomycin in cisplatin-induced ototoxicity. Methods: 22 chemotherapy naive patients with normal audition, scheduled to receive cisplatin-based chemotherapy (cumulative dose =200mg/m2) were randomized to receive placebo (n=11) or 1g of IV fosfomycin concurrent with each cisplatin administration (2–4 cycles). Primary outcome was ototoxicity when comparing audiometric studies (low and high frequencies and otoaccustic emissions) at baseline and at completion of chemotherapy. With β=0.8 and a=0.05 the study was powered to detect differences =20 dB at any given frequency. Fisher's test, Wilcoxon and Mann-Whitney test were used. Results: Groups were balanced for baseline characteristics, cisplatin dose and response rates. No differences were found when comparing ototoxicity at low frequency ranges. When analyzing high frequencies and otoaccustic emissions, 9 patients (82%) in the placebo group developed ototoxicity vs 4 (36%) in the fosfomycin group (p=0.04). The degree of hearing-loss, evaluated by comparing percentage of change in each evaluated frequency, was significantly lower in patients receiving fosfomycin (p=0.04). Other chemotherapy toxicities were similar in both groups. Conclusions: In patients with audiometric integrity, the concurrent administration of fosfomycin with cisplatin significantly reduces ototoxicity. The degree of hearing-loss is lower in patients receiving fosfomycin than in those receiving placebo. The use of fosfomycin in combination with cisplatin is safe and does not interfere with its antineoplastic activity. To our knowledge this is the first clinical-trial that demonstrates prevention and reduction of cisplatin-induced hearing-loss. No significant financial relationships to disclose.

It is now known that astrocytes are not merely supporting cells but they also play an important role in neuronal funcions. Astrocytes tightly ensheat neuronal synapses and regulate the excitation of neurons by uptaking neurotransmitters; reglulate the cerebral blood flow, cerebral fluid volume and extracellular concentrations of ions. They also supply fuel in the form of lactate and provide free radical scavangers such as glutathione for active neurons. These facts indicate that impaired function of astrocytes may lead to neuronal dysfunction. After brain injury (stroke, trauma or tumors) astrocytes are swollen and release active molecules such as glutamate or free radicals resulting in neuronal dysfunction. Thus, investigation of the molecular mechanisms of astrocyte function may reveal novel targets for the development of therapeutic tools in neuronal diseases.

Currently, the consumption of broiler-chicken meat increases up to 3.7510 kg/cap/year. This condition is due to the increasing of population growth and food businesses which use chicken meat. On the other hand, the chicken meat contains of high fat, thus easily oxidized and resulted in free radicals and off- flavor. Chicken meat is widely used as meatball that is processed through the stage of meat-milling and boiling which triggers fat oxidation. Therefore, an antioxidant is needed to inhibit oxidation. Aloevera contains flavonoid compounds that could scavange free radicals. The objective of this research was to optimize the addition of aloe vera gel in the chicken meatball to obtain high antioxidant effect and acceptable product. Considering its high water content (> 98%), in this study aloe vera gel was added as an ice-substitution in the making of meatball. The meatballs were made by mixing of 250 g chicken meat with 125 g tapioca for each sample, seasoning (salt, pepper, garlic), and added ice with water/aloe vera gel ratio (g/g) of 100/0; 85/15; 70/30; 55/45 and 40/60. The doughs were molded in ball-shape then boiled at 90 oC for 10 minutes. The meatballs were subjected to analysis of moisture content, the ability to scavenge of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical or radical scavenging activity (RSA), acid, peroxide and thyobarbituric acid (TBA) number, physical properties including water holding capacity (WHC), cooking loss, and texture (softness, chewiness and deformation) as well as acceptability by hedonic test. The results showed that the highest acceptability and antioxidative activity of meatballs was obtained in meatball with the ratio of water/gel between 55/45- 40/60 (g/g). This aforementioned meatball had softer texture and likely chewiness. The percentage of the WHC and cooking loss were not significantly different, but it had high RSA and lowest value of acid, peroxide and TBA numbers. ABSTRAKSaat ini konsumsi daging ayam ras pedaging meningkat hingga mencapai 3,7510 kg/kap/tahun. Hal ini disebabkan antara lain oleh meningkatnya jumlah penduduk dan usaha di sektor pangan yang menggunakan daging ayam ras. Disisi lain, daging ayam ras mengandung lemak cukup tinggi, sehingga mudah teroksidasi menghasilkan radikal bebas dan penurunan flavor. Daging ayam ras banyak digunakan sebagai bakso yang diolah melalui proses penggilingan daging dan perebusan, sehingga dapat memicu terjadinya oksidasi lemak. Oleh sebab itu, diperlukan antioksidan untuk menghambat oksidasi. Aloe vera diketahui mengandung senyawa flavonoid yang dapat menangkal radikal bebas. Tujuan penelitian ini adalah melakukan optimasi penambahan gel lidah buaya pada pembuatan bakso daging ayam ras untuk menghasilkan bakso dengan efek antioksidatif tinggi dan disukai. Pada penelitian ini gel lidah buaya ditambahkan untuk mensubtitusi es batu yang digunakan pada pembuatan bakso, mengingat kandungan air gel tinggi (> 98%). Pembuatan bakso untuk setiap 250 g daging ayam ditambah 125 g tapioka, bumbu (garam, merica, bubuk bawang putih) dan es batu yang dibuat dengan variasi rasio air/gel lidah buaya (g/g): 100/0; 85/15; 70/30; 55/45 dan 40/60. Bahan dicampur menjadi adonan dan dibuat bola-bakso, selanjutnya direbus pada suhu 90 oC selama 10 menit. Analisis yang dilakukan adalah kadar air, kemampuan menangkap radikal DPPH, angka asam, peroksida dan TBA (thyobarbituric acid); sifat fisik: water holding capacity (WHC), cooking loss, tekstur (kelunakan, kekenyalan dan deformasi) dan akseptabilitas bakso ditentukan secara inderawi dengan Hedonic Test. Hasil penelitian menunjukkan bahwa bakso dengan akseptabilitas dan aktivitas antioksidasi tinggi dibuat dengan es batu dengan rasio air/gel lidah buaya 55/45-40/60 (g/g). Bakso tersebut lebih lunak dan kekenyalannya disukai. Persentase WHC dan cooking loss tidak berbeda nyata, nilai RSA tinggi, sedangkan angka asam, peroksida dan TBA paling rendah.

This study investigates the antioxidant properties of aqueous extracts of Murraya koenigii (curry leaf), Aegle marmelos (bael) and Laurus nobilis (bay leaf) using in vitro assays. The plants have been traditionally used in Indian medicinal systems for the treatment of various metabolic disorders. Aqueous extracts from the leaves of Murraya koenigii, fruit pulp of Aegle marmelos and leaves of Laurus nobilis were prepared. The total phenolic content and total flavanoid content was also determined in these aqueous extracts. They were tested for their ability to scavange free radicals by DPPH assay, ABTS assay and FRAP assay which are elevated during various metabolic disorders. The results suggest that all the three plants exhibited significant antioxidant activities. But strongest antioxidant properties were exhibited by Murraya koenigii leaf extract followed by the pulp of Aegle marmelos and lowest antioxidant activity was exhibited by Laurus nobilis extract, supporting their use in traditional medicine and potential development into therapeutic agents. So, this research suggested that these medicinal plants possess a significant antioxidant potential and are important source of natural antioxidants and can be effectively used in treating oxidative stress disorders. As a result, the study's significant findings demonstrate that it is a step towards evidence-based phytomedicine.

In line with the increase in cassava production and the development of nutrient-rich cassava in order to support national food diversification and biofortification programs, the selection of selected varieties of cassava varieties, which are superior in nutrients especially rich in beta carotene is very necessary. Beta carotene is an important source of antioxidants to scavange free radicals and is a provitamin A precusor to form vitamin A. The development of superior cassava riching in beta carotene can be done through the mutation approach with gamma irradiation. The observation of changes in morphological characters and levels of beta carotene from irradiated cassava need to be done to get the superior beta carotene cassava clone candidates, which could be developed in the future. This experiment was conducted at the Biotechnology Research Center, LIPI. The sample used in this study originated from in vitro shoots from several Ubi Kuning clones resulting from 10 Gy radiation, which were then transferred to the field. Observations of morphological characters and levels of beta carotene of Ubi Kuning were carried out in the third generation, which was harvested at the age of 10 months. The morphological analysis of irradiated Ubi Kuning showed that there was a difference in the intensity of tuber color between some of irradiated Ubi Kuning clones compared to the control. The determination of beta carotene levels based on the standard beta carotene curve found that the highest content of beta carotene was found in the UK Rad 3.4 clone with beta carotene content of 0.252 μg / mL compared to the control (0.219 μg / mL). The lowest beta carotene content was obtained in UK Rad 3.3 (0.048 μg / mL), followed by UK Rad 3.2 (0.221 μg / mL) and UK Rad 4.1 (0.120 μg / mL). This shows that the irradiated Ubi Kuning at dosage of 10 Gy caused variations in the intensity of tuber colors and the content of beta carotene from the cassava.Keywords: Ubi Kuning, beta carotene, Gamma light irradiation