Enhancement of nitrite on heme-induced oxidative reactions: A potential toxicological implication

► NO2- acted as a reducing agent to remove ferryl heme. ► NO2- exerted pro-oxidant effect on heme-H2O2-induced protein oxidation at lower concentrations. ► NO2- enhanced heme-H2O2-induced loss of HepG2 cell viability dose-dependently. ► NO2- efficiently enhanced the peroxidase activity and oxidative degradation of heme.