Berberine safeguards sepsis-triggered acute gastric damage and inhibits pyroptosis in gastric epithelial cells via suppressing the ubiquitination and degradation of Nrf2.

Abstract

Berberine (BBR), a widely recognized traditional Chinese medicine, has attracted considerable attention for its promising anti-inflammatory effects. The activation of nuclear factor erythroid 2-related factor 2 (Nrf2) effectively safeguards against organ damage stemming from sepsis-induced oxidative stress and inflammatory responses. This study examined the potential of BBR in alleviating sepsis-induced acute gastric injury, with a particular focus on elucidating whether its mechanism of action involves the activation of the Nrf2 signaling pathway. Following intraperitoneal injection of BBR, mice were subjected to the cecal ligation and puncture (CLP) method to induce sepsis. In vitro experiments involved pre-treating the normal gastric epithelial cells (GES-1) with BBR, followed by treatment with lipopolysaccharide (LPS). Functional assays were then performed to assess cell proliferation and apoptosis. To validate the role of Nrf2 in pyroptosis and inflammation, siRNA targeting Nrf2 (si-Nrf2) was transfected into LPS-treated GES-1 cells. Additionally, mice were administered the Nrf2 inhibitor ML385 to confirm the protective effects of BBR in vivo. BBR displayed a dose-dependent effect in mitigating gastric tissue damage, suppressing the release of inflammatory cytokines, and reducing the expression of NLRP3, ASC, and GSDMD-N. In vitro, BBR fostered GES-1 cell proliferation, hindered apoptosis, and suppressed the levels of TNF-α, IL-18, IL-1β, NLRP3, ASC, and GSDMD-N. Further analysis revealed that knocking down Nrf2 reversed BBR's inhibitory effect on pyroptosis in LPS-treated GES-1 cells. Through binding to Keap1, BBR efficiently prevented the ubiquitination and degradation of Nrf2, ultimately promoting its nuclear translocation. In vivo experiments confirmed that ML385 reversed the protective effect of BBR on pyroptosis and inflammation. Our research reveals that BBR interacts with Keap1 to activate the Keap1/Nrf2 signaling pathway in gastric epithelial cells, thereby suppressing pyroptosis and inflammation in sepsis-induced acute gastric injury.