Whey protein boosts the antioxidant profile of rats by enhancing the activities of crucial antioxidant enzymes in a tissue-specific manner.

Whey protein, a by-product of cheese industry, is harmful for the environment (i.e., surface and subterranean waters, soil) and, therefore, for humans due to its high polluting burden. Concomitantly, it has been reported that it is a mixture with potent antioxidant action since it is rich in cysteine residues, which are necessary for glutathione synthesis in vivo. On this basis, this study intended to examine the role of whey protein on the intensification of tissue antioxidant arsenal. To this end, a dose of sheep/goat whey protein equal to 1 g/kg of body weight/day dissolved in drinking water was administered to rats for 28 consecutive days. According to our findings, whey protein improved the antioxidant profile of liver, small intestine, lung and muscle whereas it did not affect the redox state of kidney. Our results were based on the alterations found in the protein expression of glutamate cysteine ligase, catalase and superoxide dismutase-1 measured in all tissues and the activity of glutathione S-transferase evaluated in muscle. Although tissue-specific, it is obvious that the action of whey protein is biologically beneficial and could serve as a biofunctional constituent for foods able to improve redox profile when administered against redox-related diseases.