Protection of oxidative hemolysis by demethyldiisoeugenol in normal and β-thalassemic red blood cells

The purpose of this study was to evaluate the ability of demethyldiisoeugenol to protect normal and β-thalassemic human red blood cells (RBCs) against oxidative damage in vitro. Oxidative hemolysis and lipid peroxidation of normal and β-thalassemic human RBCs induced by aqueous peroxyl radical were suppressed by demethyldiisoeugenol in a concentration- dependent manner. The formation of proteins with high molecular weight and concomitant decrease of the low-molecular-weight proteins of RBCs challenge with aqueous peroxyl radical were inhibited by demethyldiisoeugenol. It also prevented the shortening of the Russell's viper venom (RVV)-clotting time mediated by prelytic radical-treated RBCs. In contrast, demethyldiisoeugenol inhibited oxidative hemolysis but not those metHb and ferrylHb formations caused by hydrogen peroxide (H₂O₂) in normal RBCs. Furthermore, demethyldiisoeugenol did not prevent the consumption of the cytosolic antioxidant, glutathione (GSH), in radical-treated RBCs. It also did not cause of a loss of sulfhydryl group during incubation with GSH. However, the diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of demethyldiisoeugenol was dramatically increased in the presence of GSH. These results imply that demethyldiisoeugenol can regenerate from its oxidized form to its active reduced form in the presence of GSH. It may be useful in diminishing oxidative damage to pathological RBCs.