Weikangling capsules combined with omeprazole ameliorates ethanol-induced chronic gastritis by regulating gut microbiota and EGF-EGFR-ERK pathway

Weikangling capsules (WKLCs) have been widely used in the treatment of chronic gastritis. Whether used alone or combined with omeprazole (OME), it shows a significant effect. However, the mechanisms haven't been established. The study aimed to explore the mechanisms of WKLCs and its combination with OME on chronic gastritis.The components of WKLCs and EA (the ethyl acetate extraction extracted from WKLCs) fraction were analyzed. Then chronic gastritis model rats were induced by 56 % ethanol and treated with OME, low dose of WKLCs (WKL), high dose of WKLCs (WKH), WKLCs combined with OME (WO), and EA fraction (EA) to evaluate the mechanisms of WKLCs, drug combination and EA fraction.A total of 22 components of WKLCs were quantified, among them 18 were enriched in EA fraction. WKLCs alleviated the morphology and inflammation of gastric mucosa and downregulated the levels of inflammatory factors (IL-1β, TNF-α, IL-6) and epidermal growth factor (EGF) in serum by inhibiting the EGF-EGFR-ERK pathway, regulating gut microbiota composition and SCFAs contents in feces. WKLCs plus OME was better than OME. EA fraction improved digestive function by increasing pepsin activity and decreasing gastrointestinal hormones (GAS and VIP) compared with WKLCs.This study elucidated that the effect of WKLCs and its combination with OME in the treatment of chronic gastritis was attributed to regulating the composition of the gut microbiota and inhibiting the EGF-EGFR-ERK pathway. The EA fraction is an inseparable effective substance of WKLCs. This study provides scientific evidence for clinical application.