Protective effects of total flavonoids from Alpinia officinarum rhizoma against ethanol-induced gastric ulcer in vivo and in vitro

CONTEXT: Alpinia officinarum Hance (Zingiberaceae) is traditionally used to treat inflammation, pain, colds and digestive diseases. OBJECTIVE: To investigate the potential protective mechanism of total flavonoids from the rhizomes of A. officinarum (F-AOH) in ethanol-induced acute gastric in vivo and in vitro. MATERIALS AND METHODS: In vivo: Gastric damage was induced in BALB/c mice by administering ethanol (10 mL/kg) after oral treatment with F-AOH at 126.8, 63.4 and 31.7 mg/kg or ranitidine (Ran) at 100 mg/kg (1 week of continuous gavage). In vitro: Gastric mucosal epithelial cells (GES-1) were incubated with F-AOH (8, 4 and 2 μg/mL) for 16 h and treated with 7% ethanol for 4 h. The extent of gastric damage was assessed histopathologically, and the expression of NF-κB, COX-2, TNF-α, iNOS and IL-1β was quantified by Western blot analysis. In addition, proinflammatory mediators and concentrations of motilin (MTL) and gastrin (GAS) were measured by ELISA test. RESULTS: F-AOH effectively reduced the ulcer index (from 23.4 ± 4.28 to 8.32 ± 1.5) and reduced release of inflammatory mediators (IL-1β, IL-6, TNF-α and PGE2), increased the content of nitric oxide and improved GAS and MTL secretion. The 50% inhibitory concentration (IC(50)) of F-AOH on cell damage was 17 μg/mL. F-AOH increased ethanol-induced cell survival (from 47 to 85%) and inhibited the expression of NF-κB, COX-2, TNF-α, IL-1β and iNOS proteins. CONCLUSIONS: F-AOH inhibits ethanol-induced gastric mucosal damage, provides a theoretical basis for galangal in the treatment of other causes of GU, and promotes the application of galanga in the treatment of GU.