Effects of pH Alteration on the Free Radical Scavenging Ability and Other Antioxidant Properties of Reduced Glutathione

Reduced glutathione (GSH), an endogenous antioxidant ubiquitously distributed in the physiological system has been widely reported to exhibit potent antioxidant properties in vivo and in vitro. However, information regarding the effects of altered pH on its widely reported antioxidant properties still remains scanty in the literature. Hence, the present study is geared towards unraveling the effect of altered pH on the antioxidant properties of GSH in vitro. This was done by measuring the effects of pH (4.4, 5.4, 6.4, 7.4, 8.4 and 9.4) on some antioxidant parameters including free radical scavenging properties against 2, 2 - diphenyl-1-picryl hydrazyl radicals (DPPH), ferric reducing properties, Fe2+- chelating properties and inhibition of both deoxyribose degradation and lipid peroxidation. Results indicated that in all antioxidant indices determined, pH alteration did not have any significant effect on the antioxidant activity of GSH in vitro. From the foregoing, it is obvious that GSH is a potential antioxidant that could be exploited for the management of pH implicated pathological conditions such as acidosis and alkalosis.