Antioxidant effects of heated garlic juice on cadmium-induced liver damage in rats as compared to ascorbic acid.

The antioxidant efficacy of heated garlic juice (HGJ) in liver was evaluated with that of ascorbic acid (AA) in rats exposed to acute dose of cadmium (4 mg kg(-1) bd. wt). The rats were either given HGJ (100 mg kg(-1) bd. wt) orally, daily for 4 weeks or AA (100 mg kg(-1) bd. wt) orally, daily for 4 weeks or both or cadmium (4 mg kg(-1) bd. wt) intraperitoneally for 3 days. Another group of rats was given cadmium (4 mg kg(-1) bd. wt) intraperitoneally for 3 days after pretreatment with either HGJ (100 mg kg(-1) bd. wt) or ascorbic acid (100 mg kg(-1) bd. wt) for 4 weeks and the liver excised. The results obtained show that AA and HGJ significantly reduced the level of liver malondialdehyde (MDA) induced by cadmium compared to control (p < 0.05) but AA tends to be more potent when compared with HGJ. The presence of either HGJ or AA also significantly reduced the levels of ROS in the presence of cadmium (Cd). The presence of either AA or HGJ pre-treatment produced significant increase in liver SOD and Catalase activities when compared with rats treated with Cd alone. There was no significant reduction in the activities of these enzymes in the presence of cadmium compared to control. Western blot shows that the expressions of Nrf2 and NQO1 in the liver were significantly increase by 3 and 1.7-fold respectively in the AA pretreated mice when compared with Cd. However no significant changes were seen in HGJ pretreated rats. The expression of HO-1 was not significantly increase in the AA pretreated rats. The results show that though both ascorbic acid and HGJ are efficient in preventing Cd-induced damage in the rat liver, ascorbic acid appeared to be a more powerful antioxidant than heated garlic juice in preventing cadmium-induced oxidative damage in liver and its action may be mediated in parts via Nrf2-keap1 pathway.