Gastroprotective and antioxidant activities of Phyllanthus amarus extracts on absolute ethanol- induced ulcer in albino rats

Abstract

This study was designed to evaluate the gastroprotective and antioxidant effects of aqueous and acetone extracts of Phyllanthus amarus leaves in albino rats. P. amarus extracts (500 and 1000 mg/Kg) as well as cimetidine (100 mg/Kg) was administered orally once a day for two weeks before challenge with absolute ethanol (1 ml/ 200 g body wt). Pretreatment with P. amarus aqueous extract (500 mg/Kg) and cimetidine inhibited the ulceration damage of absolute ethanol by 59.3 and 41.2% and decreased the serum alanine aminotransferase (ALT) by 35%, 24% and aspartate aminotransferase (AST) by 7 and 6% respectively. The acetone extract (1000 mg/Kg) also significantly increased (P < 0.01) the absolute ethanol mediated decrease in the activities of gastric mucosal catalase (CAT), superoxide dismutase (SOD) and glutathione-s-transferase (GST) by 53, 8 and 33% respectively. Cimetidine respectively caused 52, 14 and 38% significant (P< 0.01) increase on the absolute ethanol-induced decrease in the activities of CAT, SOD and GST. Furthermore, P. amarus aqueous extract (500 mg/Kg) and cimetidine were noted to increase the activities of liver CAT by 18 and 20%, SOD by 25 and 19% and GST by 122 and 54% respectively. However, the liver thiobarbituric acid reacting substances (TBARS) values of all the groups pretreated with P. amarus extracts and cimetidine were not significantly different (P < 0.05) from the ethanol group. In this study, P. amarus extracts appears to act as an in vivo natural antioxidant and an effective gastroprotective agent that is as effective as cimetidine. P. amarus may also offer protection against toxic effects of alcohol to the liver. Key words: Phyllanthus amarus; Gastroprotective activity; Antioxidant activity; Thiobarbituric acid reacting substances (TBARS); acute toxicity.