Antioxidative effects of whey protein on peroxide-induced cytotoxicity.

Myoblastic toxicity is a major adverse effect caused by reactive oxygen species (ROS) when exercising heavily. Although protection or alleviation of ROS toxicity can be achieved by administration of antioxidant vitamins such as vitamin E and vitamin C, their protective effect remains controversial. Thus, alternative natural antioxidants may be potential candidates for foods for athletes. In this research, we investigated the antioxidative effect of whey protein against hydrogen peroxide (H(2)O(2)) toxicity using C(2)C(12) myoblasts. Whey protein pre-incubation prevented the decrease in cell viability after H(2)O(2) treatment. The production of 8-hydroxydeoxyguanosine associated with DNA oxidative damage was also inhibited by the whey protein pre-incubation. Endogenous antioxidant defense, such as glutathione, catalase, and superoxide dismutase activity, was also modulated by the antioxidant. At the same time, enhanced mRNA expression levels of heme oxygenase-1 and NADPH quinone oxidoreductase-1 were observed in cells pre-incubated with whey protein before H(2)O(2) abuse. These findings suggest that whey protein improved the antioxidant capacity against acute oxidative stress through multiple pathways and this protein may serve as an alternative source of antioxidants for prevention of athletic injuries caused by ROS.