Abstract: OBJECTIVE: To investigate the effect of ethanol extracts of Muxiang(Radix Aucklandiae)(RA) on gastric ulcers in rats and explore the potential mechanisms.METHODS: A model was established by ethanol(0.75 m L/kg). According to body weight, rats were pretreated with RA extracts(2.5 or 5 g/kg). The rats were administered 95% ethanol orally after 1 h. The effects of ethanol were evaluated by measuring the gastric secretion volume, p H, pepsin activity, and ulcer area. Histological analysis and immunohistochemistry were also conducted. Furthermore, the effect of the ethanol extract of RA on transiting activity of the gastrointestinal tract was observed in mice.RESULTS: Intragastric administration of RA extracts protected the gastric mucosa from ethanol-induced gastric ulcers, while reducing submucosal edema and preventing hemorrhagic damage.Moreover, the extracts increased the production of gastric mucus, upregulated Bcl-2, and downregulated Bax expression. Importantly, pretreated rats exhibited no significant change in the gastric secretion volume, gastric juice acidity, or pepsin. Furthermore, pretreatment prominently(P < 0.05) enhanced propulsive movement of the gastrointestinal tract in normal mice and mice with gastrointestinal motility disorders.CONCLUSION: Ethanol extracts of RA ameliorated gastric lesions in the gastric ulcer rat model. The mechanisms of action were related to improvement of gastrointestinal dynamics, maintenance of mucus integrity, and inhibition of apoptosis by downregulating proapoptotic Bax protein and upregulating anti-apoptotic Bcl-2 protein.

Key words: Stomach ulcer, Gastric mucosa, Apoptosis, Genes,Bcl-2, Gastrointestinal dynamics, Muxiang(Radix Aucklandiae)