Evaluation of the antioxidant activity of Marjoram plant (Origanium Majorana L.) in CCl 4-intoxicated rats.

Aim: This work was performed to evaluate the antioxidant activity and hepatoprotective effect of methanolic extract of Marjoram plant (Origanium Majorana L.) in CCl4- intoxicated rats. Materials and Methods: A total of 25 mature albino rats (Sprague Dawley) from both sexes, weighting from140 to 170 g were used. The animals were randomly divided into 5 groups each of 5 animals. These groups were used to investigate the in vivo hepatoprotective and antioxidant effects of the tested plant extract when given orally in two doses (375 and 750 mg/kg b.wt.). The first group was kept as normal healthy control. The other four groups were given CCl4 (1 ml/kg b.wt. s.c) for five days. One of these was used as a CCl4-intoxicated non treated control. Group III and IV were given the methanol extract of Origanium majorana plant orally at doses of 375 and 750 mg/kg b.wt. per day, for two months. Group V was used as a standard group and received silymarin orally at a dose of 100 mg/kg b.w. for two months. The antioxidant activity of methanol extract of Origanium majorana plant was studied in rats liver homogenate after the prolonged oral administration (2 months) via determination of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) enzyme activity. The in vitro antioxidant activity was compared to DPPH and measured spectrophotometrically. The activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) in the different groups was evaluated as well as the histopathological examination of the liver. Results: Oral administration of Origanium majorana plant increased the antioxidant enzymes and significantly (P < 0.05) decreased liver enzyme levels when given in repeated doses. Conclusion: Thus methanolic extract of Origanium majorana possesses a significant antioxidant activity.