Effects of sheep/goat whey protein dietary supplementation on the redox status of rats

The purpose of the present study is to estimate the effects of sheep/goat whey protein dietary supplementation on the redox status of blood and tissues of rats. Twelve male Wistar rats were divided into the control group (standard commercial diet) and whey group [standard commercial diet + sheep/goat whey protein (1 g kg b.w/day)] (6 rats/group). The animals were maintainted on their respective diet for 28 days. At the end of the experimental period, reduced glutathione, catalase activity, total antioxidant capacity, thiobarbituric reactive substances, protein carbonyls and the decomposition rate of H2O2 were measured in blood and tissues of rats. According to the results, the rats fed with the sheep/goat whey protein exhibited improved antioxidant status and decreased free radical‑induced toxic effects on lipids and proteins. Specifically, in blood, GSH and CAT levels were significantly increased while TBARS and protein carbonyl levels were significantly decreased compared to the control group. Regarding the effects on tissues, it was observed that GSH levels were significantly increased in small intestine, quadriceps muscle, pancreas and lung tissue compared to the control group. The decomposition rate of H2O2 was significantly decreased in liver, brain and quadriceps muscle, but was significantly increased in spleen tissue compared to the control group. TBARS levels were significantly decreased in liver, brain, quadriceps muscle, pancreas, lung and spleen tissue compared to the control group. Finally, protein carbonyl levels were significantly decreased in brain, small intestine, kidney, pancreas and spleen tissue compared to the control group. Thus, the present findings show the beneficial effects of sheep/goat whey protein, a by‑product of cheese manufacturing, on the redox status in an in vivo model.