Antisecretory and antiulcerative effects of ethyl acetate fraction of Nigella sativa (L.) Seed extract in rats
The present work was carried out to investigate the possible effects of ethyl acetate seed fraction of Nigella sativa on gastric ulcers and basal gastric secretions using the Non-Steroidal Anti-inflammatory Drug-induced (NSAID) model. Phytochemical screening according to Trease and Evans, 2002 and acute toxicity tests using the Lorke’s Method, 1983 were conducted. For the mucosal integrity study, ulcer and preventive indices were analysed, while volume of gastric juice, titratable acidity, acid output and pepsin concentration were assessed for basal gastric secretion parameters. Phytochemical screening revealed the presence of flavonoids, alkaloids, saponins, glucocinolates amongst others, while the acute toxicity studies revealed a median lethal dose above 5000mg/kg. The rats were grouped into 9 (n = 5), with the extract fraction administered at 50, 100 and 200mg/kg subcutaneously, followed by pyloric ligation with cimetidine used as the standard drug. Five rats received normal saline 1ml/kg/rat subcutaneously (S.C) as Negative Control, Five rats received indomethacin (20 mg/kg S.C), Ten rats for the study of the effect of two different doses of cimetidine 50 and 100 mg/kg S.C (5 rats for each dose). Ten rats for the study of effect of two different doses of cimetidine (50 mg and 100 mg/kg) S.C, given 30 minutes prior to indomethacin administration (5 rats for each dose). The three experimental doses of the extract at 50,100 and 200mg/kg showed a dosedependent decrease in both ulcer and preventive indices with the 200mg/kg dose at 0.6mm and 94% respectively. It also showed a significant (p<0.05) decrease in volume of gastric juice, titratable acidity, acid output and pepsin concentration in dose-dependent manner with the three experimental doses administered with the highest reduction at the 200mg/kg dose. The results obtained suggest that this fraction down-regulated all those parameters which might be attributed to the presence of the phytoconstituents present in this fraction, particularly the flavonoids. Therefore, the extract fraction of this plant possesses gastroprotective activity further explaining the folkloric use of this plant in the therapy of peptic ulcer disease.
Keywords: Antiulcerative, Antisecretory, Nigella sativa, Phytochemicals, Rats, Seed Extracts.