Antiulcer principle from Zingiber montanum

Abstract

Ethnopharmacological relevance: Rhizome of Zingiber montanum has been extensively used as a folk medicine to ameliorate peptic ulcer at northern part of Bangladesh.

Aim of the study: To identify the antiulcer principle of the MeOH extract of the rhizome of Zingiber montanum by an ex vivo bioassay guided chromatographic separation and purification, and structure elucidation of the purified compound by spectroscopic methods.

Materials and methods: Dried powder of Zingiber montanum rhizomes was extracted with MeOH. The antiulcer activity of the crude extract and its chromatographic fractions were evaluated by the inhibition of 1N HCl induced gastric lesions in Swiss albino mice. The pure compound was purified from the active fraction by crystallization with hexanes. Structure of the pure compound was elucidated by spectroscopic methods. The antiulcer activity of the pure compound was evaluated by the inhibition of 1N HCl, 95% ethanol and indomethacin induced gastric lesions in mice.

Results: The MeOH extract of Zingiber montanum showed 61.97% and 83.10% inhibition of the 1N HCl induced gastric lesions at doses of 200mg/kg and 400mg/kg, respectively, in mice. Chromatographic separation on silica gel of the extract was yielded seven fractions and the fraction 2 was found to have most potent antiulcer activity in mice. This fraction showed 77.46% inhibition of the 1N HCl induced gastric lesions at a dose of 40mg/kg in mice. Crystallization of the fraction yielded 1 (zerumbone, 180mg). It showed statistically 45.77% and 92.25% inhibition of 1N HCl induced gastric lesions in mice at doses of 20mg/kg and 40mg/kg, respectively. It also showed 29.07% and 45.35% inhibition of 95% ethanol induced gastric mucosal damage, and 64.76% and 72.38% inhibition of indomethacin induced gastric lesions in mice at doses of 20mg/kg and 40mg/kg, respectively.

Conclusion: Zerumbone (1) showed potent cytoprotective effect against necrotizing agent (HCl) and non-steroidal anti-inflammatory drug (indomethacin) induced gastric ulceration. It also exhibited moderate cytoprotective effect against noxious agent (EtOH) induced gastric lesions. It can be considered as a promising new antiulcer natural drug lead.