Hepatic endogenous defense potential of propolis after mercury intoxication

Exposure to mercuric chloride(HgCl2;5 mg kg–1 body weight;i.p.)induced oxidative stress in mice and substantially increased lipid peroxidation(LPO)and oxidized glutathione(GSSG)levels,decreased the level of reduced glu-tathione(GSH)and various antioxidant enzymes in liver and also increased the activities of liver marker enzymes in serum.Therapy with propolis extract,a resinous wax-like beehive product(200 mg kg–1 orally,after mercury administration),for 3 days inhibited LPO and the formation of GSSG and increased the level of GSH in the liver.Release of serum transaminases,alkaline phosphatase,lactate dehydrogenase and-glutamyl transpeptidase were significantly restored after propolis treatment.The activities of antioxidant enzymes,that is,superoxide dismutase,catalase,glutathione-S-transferase and glucose-6-phosphate dehydrogenase,were also concomitantly restored towards normal levels after propolis administration.These observations clearly demonstrate that propolis treatment augments antioxidant defense against mercury-induced toxicity and provide evidence that propolis has therapeutic potential as a hepatoprotective agent.