A comparative study of the antioxidant properties of two different species of Ocimum of southern Africa on alcohol-induced oxidative stress.

The present study investigates the protective effect of methanol extract of Ocimum gratissimum (MOEG) and Ocimum canum (MOEC) from Southern Africa on the oxidative stress induced by alcohol consumption. Male Wistar rats weighing 200-250 g were divided into six groups of six rats each as follows: the normal control group was administered distilled water, the ethanol control was administered ethanol (5 g/kg), and experimental groups EX1 and EX3 were fed ethanol (5 g/kg) plus MOEG and MEOC (100 mg/kg), respectively. Two other experimental groups, EX2 and EX4, were administered MEOG and MEOC (100 mg/kg), respectively, for 30 days. At the end of the experiment, rats were sacrificed, and blood was collected to assay thiobarbituric acid-reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and vitamins E and C. Results indicated a significant reduction in the levels of TBARS, ALT, and AST and a significant increase in the levels of GSH and vitamins E and C. The level of vitamin E is greater with MOEG treatment, whereas the vitamin C level goes up with MOEC treatment. A marked improvement occurred in the activities of CAT and SOD in groups EX1 and EX3 compared to the levels with group EC. Thus the results indicated a significant protection by these extracts against ethanol-induced hepatotoxicity (P <or= .05). Again the groups that were treated with extracts only (EX2 and EX4) showed low levels of TBARS, ALT, and AST, which clearly indicates the extract had no toxic effects on hepatocytes. Comparison of results for these two Ocimum species showed no significant difference except in the levels of vitamins E and C with two treatments. Thus there is a possibility that O. canum might be participating through vitamin C and O. gratissimum through vitamin E.