Hepatoprotective effects of aqueous leaf extract and crude isolates of Murraya koenigii against in vitro ethanol-induced hepatotoxicity model.

Medicinal plants constitute a principal health care resource corroborating their gradual acceptance by the global population. The ethno medicinal plant, Murraya koeniggi (Curry-leaf tree) as is native to India exhibits diverse biological activities. Unpublished data from our laboratory revealed hepatoprotective activity of its crude aqueous extract against ethanol-induced hepatotoxicity in experimental animals. Chronic ethanol consumption diminishes the cellular antioxidant levels through free radical induced injury causing hepatitis and cirrhosis with mortality in severe cases. This provided a rationale for studying its mechanistic approaches in terms of modulation of antioxidant defenses for probable hepatoprotective activity against ethanol-induced hepatotoxicity in vitro. Based on the inhibitory concentration (IC(50)) obtained from the cell viability assay, graded concentrations of 100 μg/ml and 500 μg/ml of aqueous extract (WE), isolated carbazole alkaloids (CA) and tannin (T) fraction were chosen to study the hepatoprotective activity against ethanol-induced hepatotoxicity using liver carcinoma cell lines (Hep G(2)). Their antioxidant activity with anti-lipid peroxidation potential (LPO), effects on protein content, liver metabolizing enzymes viz., glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and the morphology of the cells were studied as parameters of hepatoprotection. The tannins and the carbazole alkaloids from the aqueous extract exhibited excellent hepatoprotective activity with respect to the different parameters studied and maintained normal morphology even after ethanolic challenge to the cells as comparable to the protection offered by the standard drug L-ornithine L-aspartate (LOLA). The modulating effect of the aqueous extract and isolates on liver metabolizing enzymes, reduction in lipid peroxidation and decreased cellular damage were found to contribute to the hepatoprotective activity.