A potential drug combination of omeprazole and patchouli alcohol significantly normalizes oxidative stress and inflammatory responses against gastric ulcer in ethanol-induced rat model

Omeprazole (OME) is a representative of proton pump inhibitors and widely used in anti-ulcer treatment. However, OME may cause some inevitable side effects and the long-term consequences of OME could increase the risk of diarrhea. Patchouli Alcohol (PA), the main extract of Pogostemonis Herba, have demonstrated benefits in treating gastric ulcer (GU) with low toxicity. The present study aimed to investigate the synergistically protective effects of OME and PA against ethanol-induced GU in rats to study the involvement of antioxidant and anti-inflammatory activities. Moreover, the anti-apoptosis, anti-oxidant and anti-inflammatory effects in H2O2-induced gastric epithelial cells (GES-1) and LPS-induced RAW264.7 cells were determined, as well as the modulation of signaling proteins. The results demonstrated that PA alone or combined with OME provided remarkable benefits by reducing ulcer areas, modulating oxidant stress and inflammatory factors and the therapeutic efficacy was showed to be dose-dependent, which were partly superior to that of high-dose OME only. Additionally, co-treated regimen could superiorly down-regulate cell apoptosis and regulate the levels of oxidant activities and inflammatory cytokines on H2O2-induced GES-1 cells and LPS-induced RAW264.7 cells, which involved with cleaved caspase 3, Bcl-2 and BAX protein expressions and MAPK pathway. We provided a new understanding that the combination of OME and PA possessed gastroprotective effects on modulating cell apoptosis, antioxidant stress and anti-inflammatory responses against GU. Therefore, PA was inferred to take a potential and critic role in gastric mucosa protection.