In vitro and in vivo hepatoprotective effect of Vitex negundo leaves

To investigate the methanol extract of leaves of Vitex negundo (Verbeneaceae) for its hepatoprotective activity against CCl₄ induced toxicity in freshly isolated rat hepatocytes, HepG2 cells and animal models. Mature leaves of Vitex negundo were collected, authenticated and subjected to methanolic extraction. Freshly isolated rat hepatocytes were exposed to CCl₄ (1%) along with/without various concentrations of the methanolic extract of Vitex negundo (50-250μg/ml) and the levels of selected liver enzymes were measured. Hepatoprotective activity of the methanolic extract of Vitex negundo (50-250μg/ml) based on the protection of human liver derived HepG2 cells against CCl₄ induced damage was determined by MTT assay. Twenty four Wistar strain albino rats (180-200 g) of either sex were used for the in vivo investigations. Liver damage was induced by administration of 30 percent CCl₄ suspended in olive oil (1 ml/kg body weight, i.p). The animals were divided into four groups. Group I received the vehicle (Sodium CMC 0.3%). The second group received CCl₄ (1 ml/kg body weight, i.p). Group III received methanolic extract of Vitex negundo (200mg/kg body weight), and group IV received the standard drug Silymarin (250mg/kg body weight). The animals received these treatments by the oral route for a period of 7 days. On the seventh day except group I, all other groups received 30 percent CCl₄ suspended in olive oil (1 ml/kg body weight) intra-peritoneal. After 24 h of intoxication, on the 8th day, blood was collected; serum separated and various biochemical parameters were estimated. The antihepatotoxic effect of the methanolic extract was observed in freshly isolated rat hepatocytes at very low concentrations (50-250μg/ml) and was found to be superior to that of the standard used. A dose dependent increase in the percentage viability was observed when CCl₄ exposed HepG2 cells was treated with different concentrations of the methanolic extract of Vitex negundo. The highest percentage viability of HepG2 was observed at a concentration of 250μg/ml. Its in vivo hepatoprotective effect at 200 mg/kg body weight was comparable with that of the standard at 250mg/kg body weight. The methanolic extract was able to normalise the biochemical levels which were altered due to CCl₄ intoxication in freshly isolated rat hepatocytes and also in animal models.