Protective effects of ginger (Zingiber officinale Roscoe) against cadmium chloride-induced oxidative stress in the blood of rats

Cadmium is a heavy metal of wide occupational and environmental contamination. In recent years, however, cadmium has been implicated in the pathogenesis of several clinical disorders. Generation of oxidative stress is one of the plausible mechanisms for cadmium-induced diseases. The aim of the study was to investigate the effect of ginger on oxidative stress in rats exposed to cadmium (Cd) of a dose (10 mg/kg b.w.). Ginger was administered orally (500 mg/kg b.w.). After 26 days, significant increases in methemoglobin% (metHb%), carboxyhemoglobin% (HbCO%), glutathione peroxidase (GPx) activity, malondialdehyde (MDA) concentration and hemolysis%  were observed in cadmium exposed rats compared to control group (P < 0.05), while glutathione-S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) showed insignificant changes. Cadmium treatment of rats caused a significant decrease in oxyhemoglobin% (HbO2%) and total blood hemoglobin (Hb) concentration (P < 0.05). Ginger treatment of cadmium exposed rats significantly lowered metHb% (P < 0.05), while significantly increased HbO2% (P < 0.05) and total Hb concentration (P < 0.01), compared to cadmium alone group. Also ginger treatment significantly increased GPx and G6PD activities of cadmium exposed rats compared to cadmium alone group (P < 0.05). The treatment of Cd-exposed animals with ginger lowered MDA concentration and hemolysis% by 20% and 17%, respectively. From these findings it can be concluded that ginger is a strong antioxidant plant that protects the blood of rats against the adverse harmful effects of cadmium chloride exposure as well as cadmium chloride-induced oxidative stress.   Key words: Cadmium, ginger, oxidative stress, erythrocytes, hemolysis, hemoglobin derivatives, rats.