Anisodamine hydrobromide ameliorates acute lung injury via inhibiting pyroptosis in murine sepsis model

Sepsis can have severe implications on lung function, leading to acute lung injury (ALI), a major contributor to sepsis-related mortality. Anisodamine hydrobromide (Ani HBr), a bioactive constituent derived from the root of Scopolia tangutica Maxim, a plant endemic to China, has demonstrated efficacy in treating septic shock. We aim to explore whether Ani HBr can alleviate sepsis-triggered ALI and elucidate the fundamental mechanisms involved.

The protective effects of Ani HBr were assessed in two models: in vitro, lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and in vivo, cecal ligation puncture (CLP)-induced sepsis. To measure the cell viability of RAW264.7 cells after Ani HBr treatment, we used the CCK-8 assay. We quantified the levels of pro-inflammatory cytokines expression using ELISA. We also measured the expression of pyrotosis indicators by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence.

Our study demonstrates that Ani HBr can alleviate pulmonary edema, bleeding, and excessive inflammation induced by CLP. Additionally, it exhibits protective effects against cytotoxicity induced by LPS in RAW264.7 macrophage cells. Furthermore, Ani HBr downregulates the mRNA and protein levels of NLRP3, Caspase-1, GSDMD, IL-18, and IL-1β in both animal models and cell cultures, thereby inhibiting pyroptosis in a similar mechanism to AC-YVAD-CMK (AYC)'s blockade of Caspase-1. Moreover, Ani HBr suppresses the production and release of proinflammatory cytokines.

These findings suggest that Ani HBr could serve as a protective agent against sepsis-induced ALI by suppressing pyroptosis.