Protective effects of quercetin against oxidative stress induced by sodium fluoride intoxication in rat erythrocytes were evaluated. Rats were divided into five groups consisting of 10 in each for this experiment. The animals of group I received water and standard diet to serve as control group, the animals of groups II and III were treated with quercetin (10 and 20 mg kg−1 body weight), administrated intraperitoneally for 7 days followed by sodium fluoride (600 ppm) in drinking water for the next 7 days. The animals of group IV were treated with vitamin C (10 mg kg−1) intraperitoneally for 7 days followed by sodium fluoride treatment for next 7 days serving as positive control group. The animals of group V were treated only with sodium fluoride (600 ppm) for the same time and were used as control group. Blood sample were collected via retro-orbital puncture. The antioxidant enzymes, superoxide dismutase, and catalase, as well as the levels of reduced glutathione and lipid peroxidation end products were measured in erythrocytes. There was a significant increase in lipid peroxidation along with a decrease in superoxide dismutase activity in the erythrocytes of sodium fluoride-treated animals. Quercetin treatment prior to fluoride administration normalized the levels of all parameters measured in the rat erythrocytes.
