Paeonol, a major ingredient isolated from Moutan Cort, has various pharmacological effects. Our previous studies have shown that paeonol can exert antioxidant and anti-inflammatory therapeutic effects on ethanol-induced experimental gastric ulcer (GU). Therefore, in this study, we designed two GU models in rats induced by pyloric ligation (PL) and acetic acid and evaluated the protective effects of paeonol and gastroretention tablets of paeonol (GRT-Ps; 24, 48, and 96 mg/kg) on GU in rats and the effect of paeonol (48 mg/kg) on the intestinal flora. In vivo experiments showed that paeonol or GRT-Ps remarkably reduced gastric mucosal damage in a dose-dependent manner in the different types of models and improved the superoxide dismutase (SOD) activity and the malondialdehyde (MDA) content. And in fact, the sustained-release effect of GRT-Ps is more conducive to the improvement of GU compared with the rapid clearance of free drugs. In the PL-induced model, gastric secretion parameters, that is, pH and total acid, showed significant differences compared with the model group. In addition, paeonol treatment can improve the richness and diversity of the intestinal flora and increase the amount of beneficial bacteria, such as Lactobacillus. Paeonol and its stable sustained-release tablet GRT-Ps can promote ulcer healing by inhibiting oxidative stress and regulating the intestinal flora. This study can provide basis for the clinical treatment of GU with paeonol. Graphical Abstract.
Keywords: acetic acid; gastric ulcer; gastroretention tablets of paeonol; intestinal flora; paeonol; pyloric ligation.