Ainsliaea fragrans Champ. alleviates endometritis by modulating the STING-TBK1-IRF3 and NLRP3 inflammasome signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ainsliaea fragrans Champ. (AFC) is a traditional Chinese medicine used for gynecological inflammations. However, its specific effects and molecular mechanisms in treating endometritis remain unclear. AIM OF THE STUDY: The primary objective of this work was to assess the protective effects of AFC in a murine model of LPS-induced endometritis and to decode the signaling pathways involved. MATERIALS AND METHODS: Mice with LPS-induced endometritis were given AFC (0.5, 1, 2 g/kg) or dexamethasone to assess its protective effects. Uterine pathological changes, inflammatory cytokine levels, and immune cell infiltration were assessed. Complementary transcriptomic and proteomic analyses were performed to identify key pathways, followed by in vitro validation in THP-1 cell using mitochondrial function assays, immunofluorescence, Western blotting, and co-immunoprecipitation. RESULTS: AFC significantly alleviated LPS-induced uterine swelling, diminished the levels of IL-1β and TNF-α, ameliorated histopathological damage, and decreased neutrophil and macrophage infiltration. Integrative omics analysis identified the cytosolic DNA-sensing and NOD-like receptor signaling pathways as core mechanisms. The anti-inflammatory mechanism of AFC involved multifaceted regulation of the STING-TBK1-IRF3 signaling and NLRP3 inflammasome pathways. On one hand, AFC maintained mitochondrial homeostasis by upregulating membrane potential, attenuating ROS overproduction, and blocking mtDNA escape into the cytosol, which in turn inactivated the STING-TBK1-IRF3 cascade. On the other hand, AFC reduced NLRP3 and cleaved Caspase-1 abundance, abrogated their interaction, and thus impeded NLRP3 inflammasome complex formation. CONCLUSION: AFC alleviates LPS-induced endometritis through the STING-TBK1-IRF3 signaling pathway and the NLRP3 inflammasome signaling pathway, representing a promising candidate drug with early-interventional or preventive potential.