Gastric protective effect of Alpinia officinarum flavonoids: mediating TLR4/NF-κB and TRPV1 signalling pathways and gastric mucosal healing

CONTEXT: Our previous studies have found that total flavonoid of Alpinia officinarum Hance (Zingiberaceae) (F.AOH) had protective effects on gastric ulcer (GU). OBJECTIVE: To investigate the protective mechanism of F.AOH on acetic acid-induced chronic GUs in rats and ethanol-induced GES-1 cells damage. MATERIALS AND METHODS: In vivo: Gastric damage was induced in SD rats by administering acetic acid after oral treatment with F-AOH at 54, 27 and 13.5 mg/kg (2 weeks of continuous gavage). After a comprehensive evaluation of rats’ serum and gastric tissue-related indicators, gene transcriptome sequencing, qPCR and Western blotting were used to investigate the mechanism further. In vivo: GES-1 cells were incubated with F-AOH (8, 4 and 2 μg/mL) for 16 h and treated with 7% ethanol for 4 h. Transwell and flow cytometry were employed to detect migration and apoptosis of cells. RESULTS: F.AOH effectively reduced the area of GUs in rats (from 11.2 ± 1.89 to 2.19 ± 0.95), reversing ethanol-induced cells apoptosis (from 23 ± 1.3 to 8.11 ± 0.93%). It also inhibited the expression of endothelin-1 (ET-1) and iNOS proteins, decreasing the levels of TNF-α IL-6 in serum, improving oxidative stress levels and increasing the expression of Bcl-2/Bax dimer genes. In addition, 4005 differentially expressed genes between the acetic acid model and the drug groups. Through experimental verification, F.AOH can inhibit the activation of TLR4/NF-κB signalling pathway and TRPV1 receptor. CONCLUSIONS: F.AOH, as an effective gastric protective plant component, had potential therapeutic value in anti-inflammatory pain and antioxidative stress gastrointestinal diseases.