Improvement effect of green tea on hepatic dysfunction, lipid peroxidation and antioxidant defence depletion induced by cadmium
We have evaluated the antioxidant effect of green tea on cadmium-induced hepatic dysfunction and stress oxidant in rats. Adult male Wistar rats were administered cadmium by injection with 20 μmoles/Kg bw/3 days for six months. Results revealed a significant (p < 0.05) liver dysfunction, lipid peroxidation and a decline in antioxidant enzymes activities in the liver of cadmium-treated rat compared to control. Compared to vehicle control, the activity of lactate dehydrogenase (LDH), gammaglytamyl transferase (GGT), acid phosphatase (PAC), phosphatase alkaline (PAL), as well as bilirubin and thiobarbituric acid-reactive substances (TBARs) rates were significantly (p < 0.05) increased. Moreover, antioxidants enzymes activities such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, were significantly (p < 0.05) decreased in the liver of cadmium-treated rats. The oral administration of five percent aqueous green tea extract along with cadmium treatment for six months caused a significant (p < 0.05) improvement in cadmium-induced toxicity by significantly decreasing (p < 0.05) the activities of enzymatic markers of liver dysfunction (LDH, GGT, PAC, PAL activities as well as bilirubin rate). Indeed, green tea extract significantly increased (p < 0.05) the enzymatic antioxidants activities (SOD, catalase, GPX) in of rats liver compared with those given cadmium alone. Thus, the oral administration of green tea along with cadmium significantly (p < 0.05) improves cadmium-induced liver dysfunction and stress oxidant in rats' liver.