Amomum cardamomum L. ethyl acetate fraction protects against carbon tetrachloride-induced liver injury via an antioxidant mechanism in rats

BACKGROUND Medicinal herb-derived drug development has become important in the relief of liver pathology. Amomun cardamomum is traditionally used therapeutically in Korea to treat various human ailments including dyspepsia, hiccupping, and vomiting. We investigated to assess the protective effect of A. cardamomum on carbon tetrachloride (CCl4)-induced liver damage through antioxidant activity in hepatic tissues of Sprague-Dawley rats. METHODS Antioxidant properties of different fractions from A. cardamomum from ethanol extracts were evaluated by an in vitro free radical scavenging systems. The protective effect of the ethyl acetate fraction from A. cardamomum (EAAC) against CCl4-induced cytotoxicity was determined by a cell viability assay using HepG2 hepatocarcinoma cells. In vivo study, the influence of EAAC concentrations of 100 and 200 mg/kg following CCl4-induced hepatic injury was assessed. Serum levels of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and alkaline phosphatase (ALP) were determined, as was lipid peroxidation (malondialdehyde, MDA). Effect of EAAC on liver detoxification enzymes including superoxide dismutase (SOD), total glutathione (GSH), and glutathione S-transferase (GST) activity was measured in rat liver homogenates. Liver cytochrome P450 (CYP2E1) expression level was determined by quantification of mRNA. RESULTS Phytochemical analysis of A. cardamomum indicated that EAAC was enriched in total polyphenol and total flavonoid. Most of the tannins were confined to the hexane fraction. Hepatoprotective properties of EAAC were evident, with significantly reduced serum levels of GOT, GPT, and ALP compared with the control group. Improved hepatic antioxidant status was evident by increased SOD, GSH, and GST enzymes in rat liver tissue. Liver lipid peroxidation induced by CCl4 was apparent by increased intracellular MDA level. EAAC suppressed lipid peroxidation as evidenced by the significant decrease in MDA production. Expression of CYP2E1 was also significantly decreased at the higher concentration of EAAC, indicating the hepatoprotective efficacy of EAAC on acute liver damage. CONCLUSION These results indicated that EAAC has a significant hepatoprotective activity on CCl4-induced acute hepatic injury in rats, which might be derived from its antioxidant properties and CYP2E1 downregulation.