Gastric Ulcer Healing Activity against Acidified Ethanol-Induced Gastric Ulcer and Gastroprotective Mechanisms of Zingiber simaoense Rhizome Ethanol Extract in Rats

Background: Zingiber simaoense Y. Y. Qian (Zingiberaceae) rhizomes have been widely used to alleviate gastric disorders in Thai traditional medicine. Objectives: This study aimed to investigate the gastric ulcer healing activity of Z. simaoense rhizome ethanol extract (ZSE) against acidified ethanol-induced gastric ulcer and its possible gastroprotective mechanisms. Materials and Methods: The gastric ulcer healing activity of ZSE was evaluated using an acidified ethanol-induced gastric ulcer model in rats. The involvement of endogenous nitric oxide (NO) and sulfhydryl (SH) compounds in ZSE gastroprotection was also examined in addition to the determination of NO, malondialdehyde (MDA), and prostaglandin (PG) E-2 levels in rat gastric tissues as well as the determination of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic content in ZSE. Results: ZSE at the dose of 240 mg/kg/day significantly accelerated gastric ulcer healing when observed on days 4 and 8 following ulcer induction. Pretreatment with either N-G-nitro-L-arginine methyl ester or N-ethylmaleimide inhibited the gastroprotective activity of ZSE. Moreover, ZSE significantly increased NO and PGE(2) levels and decreased MDA levels in rat gastric tissues. DPPH radical scavenging activity and total phenolic compounds were also presented in ZSE. Conclusion: This study demonstrates the gastric ulcer healing activity of ZSE against acidified ethanol-induced gastric ulcer in rats. The possible gastroprotective mechanisms underlying the cytoprotective effect of ZSE might also involve gastric mucosal NO, SH compounds, and PGE(2) as well as its antioxidant activities.