Effect of buckwheat sprouts and groats on the antioxidant potential of blood and caecal parameters in rats.

The aim of this study was to investigate whether dietary buckwheat sprouts, cultivated without or with light exposure, exerted different effects on the lower gut, antioxidant status, and lipoprotein profile in rats. For 4 weeks, rats were given a diet containing 30 % expanded buckwheat seeds or 5 % buckwheat sprouts, cultivated with or without light exposure. Buckwheat sprouts that were cultivated under light and dark conditions, and expanded seeds, differed in the levels of total phenolic compounds and Trolox Equivalent Antioxidant Capacity values. All buckwheat products added to the diets decreased pH value and dry matter concentration in the caecal digesta compared with the control group. As compared to the control group, the addition of buckwheat products caused a higher glycolytic activity and the production of short-chain fatty acids in the caecum of the rats. There were no significant differences in the plasma concentrations of glucose, total cholesterol, nor triglycerides between the groups. The concentration of high-density lipoprotein (HDL)-cholesterol was significantly higher, and the atherogenic index of plasma was lower in rats administered buckwheat sprouts cultivated in the light, compared to the group fed sprouts cultivated in the dark. Total plasma antioxidant status, activity of glutathione peroxidase, and superoxide dismutase in whole blood were not affected by dietary treatment. Results of the experiment indicated enhanced benefits of dietary supplementation with buckwheat sprouts cultivated under light, especially in relation to the serum lipoprotein profile.

Extract of green tea leaves partially attenuates streptozotocin-induced changes in antioxidant status and gastrointestinal functioning in rats.

Rats with severe streptozotocin (STZ)-induced diabetes were subjected to dietary green tea extract supplementation at 2 doses (0.01% and 0.2%; GTL and GTH groups, respectively) to evaluate their effects on antioxidant, gastrointestinal, and renal parameters of experimental animals. The lower dietary supplementation reflects daily consumption of 3 cups of green tea for an average adult weighing 70 kg. Supplementation of a diet with green tea extract had no influence on elevated food intake, body weight loss, increased glucose concentration, or declined antioxidant capacity of water-soluble substances in plasma in the diabetic rats. In cases of intestinal maltase activity, attenuation of liver and kidney hypertrophy, triacylglycerol concentration, and aspartate aminotransferase activity in the serum, both dietary treatments normalized metabolic disorders caused by STZ injection to a similar extent. Unlike the GTL group, the GTH treatment significantly ameliorated development of diabetes-induced abnormal values for small intestinal saccharase and lactase activities, renal microalbuminuria, thiobarbituric acid-reactive substance content in kidney tissue, as well as total antioxidant status in the serum of rats. The GTH group was also characterized by higher antioxidant capacity of lipid-soluble substances in plasma and superoxide dismutase activity in the serum. Although the higher dose of green tea extract did not completely protect against STZ-induced hyperglycemia and oxidative stress in experimental rats, this study suggests that green tea extract ingested at high amounts may prove to be a useful therapeutic option in the reversal of diabetic dysfunction.