The effect of two extracts of Parquetina nigrescens on mucosal antioxidants defense system in ethanol-induced ulcer in rats was studied. Activities of superoxide dismutase (SOD), catalase (CAT) and levels of reduced glutathione (GSH) were determined in the gastric mucosa and liver of normal and experimental groups of rats. The rats were pretreated with 500 and 1000 mg kg-1 of hexane and chloroform extracts of P. nigrescens, respectively dissolved in olive oil for a period of 14 days prior to ethanol induction. It was found that prior to ulcer induction, 14 days pretreatment with hexane and chloroform extract P. nigrescenes significantly reduced ethanol-induced gastric damage. The levels of GSH and activities of the antioxidants enzymes (SOD and CAT) were depressed significantly (p<0>P. nigrescens was found to exact a significant gastro protective and antiulcer effect partly by protecting against the ethanol-induced ulcerogenic effects in experimental rats and probably through the induction of antioxidant enzymes.