Suppression of oxidative stress by grape seed supplementation in rats

Polyphenol-rich grape seeds have a beneficial effect on human health. The present study was performed to investigate the effects of grape seeds on antioxidant activities in rats. Male Sprague-Dawley rats were randomly divided into a control diet group (C), a high-fat diet group (HF), a 5% grape seed-supplemented control diet group (G), and a 5% grape seed-supplemented high-fat diet group (HG). Dietary supplementation with grape seeds reduced serum concentrations of lipid peroxides compared with those in the C and HF groups. The hepatic level of lipid peroxides decreased significantly in the grape seed groups compared with that in the C and HF groups. Superoxide dismutase activity in the G group increased significantly compared with that in the C group. Catalase activity tended to be higher by feeding grape seeds. The grape seed diet increased glutathione peroxidase activity in the C group. Glutathione-S-transferase activity increased significantly in the G group compared with that in the C group. Hepatic content of total glutathione increased significantly in the HG group but decreased significantly in the HF group. The ratio of reduced glutathione and oxidized glutathione increased by feeding the grape seed diet. Total vitamin A concentration was significantly higher in HG group than in other groups. Liver tocopherol content of the G and HG groups was significantly higher than that of the control groups. These results suggest that dietary supplementation with grape seeds is beneficial for suppressing lipid peroxidation in high fat-fed rats

Hypoglycaemic and Hypolipidaemic Effects of Withania somnifera Root and Leaf Extracts on Alloxan-Induced Diabetic Rats

Withania somnifera is an important medicinal plant, which is used in traditional medicine to cure many diseases. Flavonoids were determined in the extracts of W. somnifera root (WSREt) and leaf (WSLEt). The amounts of total flavonoids found in WSREt and WSLEt were 530 and 520 mg/100 g dry weight (DW), respectively. Hypoglycaemic and hypolipidaemic effects of WSREt and WSLEt were also investigated in alloxan-induced diabetic rats. WSREt and WSLEt and the standard drug glibenclamide were orally administered daily to diabetic rats for eight weeks. After the treatment period, urine sugar, blood glucose, haemoglobin (Hb), glycosylated haemoglobin (HbA1C), liver glycogen, serum and tissues lipids, serum and tissues proteins, liver glucose-6-phosphatase (G6P) and serum enzymes like aspartate transaminase (AST), alanine transaminase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) levels were determined. The levels of urine sugar, blood glucose, HbA1C, G6P, AST, ALT, ACP, ALP, serum lipids except high density lipoprotein-bound cholesterol (HDL-c) and tissues like liver, kidney and heart lipids were significantly (p < 0.05) increased, however Hb, total protein, albumin, albumin:globulin (A:G) ratio, tissues protein and glycogen were significantly (p < 0.05) decreased in alloxan-induced diabetic rats. Treatment of the diabetic rats with WSREt, WSLEt and glibenclamide restored the changes of the above parameters to their normal level after eight weeks of treatment, indicating that WSREt and WSLEt possess hypoglycaemic and hypolipidaemic activities in alloxan-induced diabetes mellitus (DM) rats

Les polyphénols bioactifs de l'aubépine (Cratoegus monogyna jacq.) et du sarrasin (Fagopyrum esculentum moench.) (obtention in vivo et in vitro)

Les polyphenols, specialement les flavanols et les flavonoides, sont deja connus comme antioxydants, diminuant notamment l'incidence de diverses pathologies cardiovasculaires dont l'atherosclerose. Deux plantes, l'une d'interet therapeutique, l'aubepine, l'autre d'interet alimentaire, le sarrasin, sont etudiees en tant que sources de phenols bioactifs. L'analyse phenolique qualitative et quantitative des differentes sources est completee par l'etude pharmacologique de leurs effets antioxydants, comparativement a des substances etalons dont certaines hors commerce (proanthocyanidines dimeres b 2 et b 5) qui ont ete isolees par gel filtration et identifiees par rmn. Les teneurs en polyphenols des colonies tissulaires d'aubepine ont ete augmentees par des modifications du milieu de culture et nous avons pu montrer que les anthocyanes sont des marqueurs visibles de la synthese d'autres phenols, specialement des flavanols et des flavonoides. L'application de ce milieu aux suspensions cellulaires induit une production en phenols totaux et en flavanols de 10 a 20 fois superieure a celle des colonies, faisant de ce materiel une source potentielle pour la production en masse et l'obtention de phenols a valeur ajoutee. Parmi les tissus d'aubepine testes, les fleurs et sommites fleuries montrent les meilleurs inhibitions de l'auto-oxydation des ldl humaines, qui semblent essentiellement liees aux teneurs en derives comme les flavanols (dont la proanthocyanidine dimere b 2 qui a presente une grande activite) et en flavonoides souvent moins actifs (hyperoside). Le sarrasin, tres etudie pour son contenu en rutine, montre des activites antioxydantes interessantes bien qu'inferieures a celles des fleurs d'aubepine, mais differant selon la variete et la partie de la graine etudiee.LILLE1-BU (590092102) / SudocSudocFranceF

Antimicrobial activity of extracts from Tamarindus indica L. leaves

Tamarindus indica L. leaves are reported worldwide as antibacterial and antifungal agents; however, this observation is not completely accurate in the case of Cuba. In this article, decoctions from fresh and sun dried leaves, as well as fluid extracts prepared with 30 and 70% ethanol-water and the pure essential oil from tamarind leaves were microbiologically tested against Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomona aeruginosa and Candida albicans. Aqueous and fluid extracts were previously characterized by spectrophotometric determination of their total phenols and flavonoids, while the essential oil was chemically evaluated by gas chromatography/mass spectroscopy (GC/MS). Experimental data suggest phenols as active compounds against B. subtilis cultures, but not against other microorganisms. On the other hand, the essential oil exhibited a good antimicrobial spectrum when pure, but its relative low concentrations in common folk preparations do not allow for any good activity in these extracts