Protective Effect of Nigella sativa Seeds Extract against Ethanol-Induced Gastric Ulcer in Rats: Possible Soluble Epoxide Hydrolase Inhibition

Abstract

Nigella sativa seeds methanolic extract was prepared by a simple maceration process. The extract was subjected to preliminary phytochemical screening and high-performance thin-layer chromatography for linoleic and linolenic acid and tested for in vitro soluble epoxide hydrolase inhibition activity. Then the extract (100, 150 and 200 mg/kg) was evaluated against ethanol-induced stomach ulcer in rats using 1-(1-propanoylpiperidin-4-yl)-3-(4-trifluoromethoxy)phenyl) urea (1 mg/kg) and omeprazole (20 mg/ kg) as reference standards. The plant extract contains flavonoids, alkaloids, proteins, free amino acids, tannins, flavonoids and linoleic acid. The in vitro soluble epoxide hydrolase inhibition test results reveal that Nigella sativa seeds methanolic extract inhibit human soluble epoxide hydrolase enzyme (half maximal inhibitory concentration=2.619 μg/ml). The Nigella sativa seeds methanolic extract reversed macroscopic and microscopic alteration and attenuated the levels of myeloperoxidase, tumour necrosis factor-alpha, interleukin-6, 5-hydroxyeicosatetraenoic acid in ulcer rats. These results were comparable with standard control. In conclusion, Nigella sativa seeds methanolic extract has a protective action against ethanolinduced ulcers in rats.