Comparison between the Antioxidant Properties of Quercetin and Combined Vitamin E and Selenium to Ameliorate the Oxidative Stress Induced by Cadmium Toxicity

Quercetin is the most prevalent flavonoid; its bioactivities have a preventive role in helping protect cells against various damaging effects. Complex vitamin E and selenium help enhance the immune system and maintain brain and heart health, as well as keep normal cell division. Cadmium is a hazardous heavy metal that exists naturally, and both occupational and environmental exposure to cadmium were reported. The present study was undertaken to compare the efficiency of quercetin against combined vitamin E and selenium to ameliorate the oxidative stress induced by cadmium toxicity. Four groups of rats, 20 animals each, were used: control, cadmium, cadmium and vitamin E plus selenium, and cadmium and quercetin. The administration of cadmium, vitamin E, selenium, and quercetin was done through the oral route and there was a gap (10 h) between the administration of cadmium and receiving vitamin E and selenium or quercetin. Concerning the incidence rate of cadmium toxicity, all rats exposed to cadmium exhibited the effect of cadmium toxicity as evidenced by decreased haematological parameters and altered biochemical profile. Compared to decrements of the parameters recorded in cadmium-exposed rats, the haematological parameters estimated in animals exposed to cadmium and then given vitamin E and selenium or quercetin were relatively improved toward the control levels. Insignificant differences were recorded between cadmium-exposed animals that received vitamin E plus selenium or quercetin. The recorded parameters of the altered biochemical profile of cadmium-exposed animals were relatively brought back toward the control levels in rats exposed to cadmium and then given vitamin E and selenium or quercetin. Based on the encountered haematological parameters and biochemical profile, it was concluded that the ameliorating effect of quercetin compared to that of combined vitamin E and selenium on the cadmium-induced oxidative stress is comparable. Both quercetin and combined vitamin E and selenium as dietary supplements exhibited efficacy in ameliorating cadmium-induced oxidative stress and maintaining the endogenous antioxidant system.