Protective role of β-patchoulene from Pogostemon cablin against indomethacin-induced gastric ulcer in rats: Involvement of anti-inflammation and angiogenesis

Abstract

Background: Non-steroidal anti-inflammatory drugs (NSAIDs) are most widely used as effective anti-inflammatory agents. However, their clinical application brings about inevasible gastrointestinal side effects. Pogostemon cablin is a traditional herbal medicine used for the treatment of gastrointestinal diseases in China. One of its representative components, the tricyclic triterpenoid β-patchoulone (β-PAE) has demonstrated great anti-inflammatory activity and gastroprotective effect against ethanol-induced gastric injury, but its protective effect against gastric ulcer induced by indomethacin is still unknown.

Purpose: To assess the protective effect of β-PAE against ulcer produced by indomethacin and reveal the underlying pharmacological mechanism.

Study design: We used an indomethacin-induced gastric ulcer model of rats in vivo.

Methods: Gastroprotective activity of β-PAE (10, 20, 40 mg/kg, i.g.) was estimated via indomethacin-induced gastric ulcer model in rats. Histopathological and histochemical assessment of ulcerated tissues were performed. Protein and mRNA expression were determined by Elisa, Western blotting and qRT-PCR.

Results: β-PAE could inhibit ulcer formation. Histopathological and histochemical assessment macroscopically demonstrated that β-PAE alleviates indomethacin-induced gastric ulceration in dose-dependent manner. After administration of β-PAE, elevated tumor necrosis factor -α level was significantly decreased and the phosphorylation of JNK and IκB was markedly inhibited. β-PAE suppressed the levels of E-selectin, P-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule and monocyte chemoattractant protein 1, as well as myeloperoxidase. Meanwhile, β-PAE increased cyclooxygenase enzyme activities (COX-1 and COX-2) to enhance the production of prostaglandin E₂. Proangiogenic protein, vascular endothelial growth factor and its receptor fms-like tyrosine kinase-1 mRNA expression were promoted while anti-angiogenic protein, endostatin-1 and its receptor ETAR mRNA expression were decreased.

Conclusion: β-PAE may provide gastroprotection in indomethacin-induced gastric ulcer in rats by reducing inflammatory response and improving angiogenesis.

Keywords: Antiulcer; Gastric ulcer; Indomethacin; Pogostemon cablin; β-patchoulene.