摘要: AIM:A decoction of Elephantopus scaber(Asteraceae) root is used to treat liver disorders in Indian and Chinese traditional medicine.The study was designed to examine the dose response effects of E.scaber methanolic extract on rats exposed to N-nitrosodiethylamine(NDEA) induced hepatotoxicity(0.02% NDEA in water five days per week,per oral) in preventive and curative models.METHODS:In preventive groups,NDEA was administered for six weeks.Daily doses of E.scaber methanolic extract(200 and 100 mgkg-1) started one week before the onset of NDEA intoxication and continued for six weeks.In curative animals,NDEA was administered for six weeks followed by treatment with the methanolic n-hexane extract of E.scaber(200 and 100 mgkg-1) for ten days.RESULTS:E.scaber extract treatment significantly(P0.05) reduced the levels of AST,ALT,and MDA in both experimental groups.The extract also enhanced the antioxidant enzyme and protein levels in rats intoxicated with NDEA.Treatment with the extract dose dependently protected the liver from NDEA-induced hepatotoxicity with normal hepatocytes and uniform sinusoids,but in some areas showed degenerating hepatic cells in both treatment groups.CONCLUSION:E.scaber methanolic extract dose dependently prevented and reversed the hepatotoxicity induced by NDEA in both experimental models.