Possible Interaction: Dehydroascorbic Acid and Glutathione

“These results show that the rate of DHA reduction depends not only on the level of reduced glutathione , but also on the rate of NADPH production, contradicting the conclusions of some previous studies.”

“In both cell types, DHA reduction lowered glutathione ( GSH ) concentrations and was inhibited by prior depletion of GSH with diethyl maleate, buthionine sulfoximine, and phenylarsine oxide.”

“Reduction of DHA , either when added to the cells or when generated in response to ferricyanide, caused significant decreases in intracellular GSH concentrations.”

“Reduction of dehydroascorbic acid DHA ) required GSH and was both direct and enzyme dependent.”

“The two-electron-oxidized form of ascorbic acid, dehydroascorbic acid (DHA) was rapidly taken up by erythrocytes and reduced to ascorbate, which reached intracellular concentrations as high as 2 mM. In the absence of D-glucose, DHA caused dose-dependent decreases in erythrocyte GSH , NADPH, and NADH concentrations.”

“ Glutathione was capable of reducing dehydroascorbic acid by a direct chemical reaction, but only when present in a greater than 10-fold stoichiometric excess over dehydroascorbic acid.”

“It was previously reported by Bhattacharya, Robson and Stewart3 that dehydroascorbic acid causes a precipitous but temporary fall in the reduced glutathione content of rat liver.”

“Their results suggested that the fall in reduced glutathione was not due to oxidation but due to a complex formation between the sulphydryl group of glutathione and dehydroascorbic acid.”

“Intracellular DHA induced a rapid and dramatic decrease in reduced glutathione that was immediately followed by a spontaneous recovery.”

“In turn, GSH levels were inversely correlated with uric acid (r=−0.451) and DHAA levels (r=−0.460).”

“Moreover, DHA not only reversed the decrease in the glutathione (GSH) levels, but also significantly enhanced it by stimulating the pentose phosphate pathway (PPP) 15 hr after H2O2 exposure.”