Senkyunolide I Inhibits mtDNA-cGAS-STING Signaling in Macrophages via Targeting VDAC1 Oligomerization to Attenuate Ulcerative Colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with limited therapeutic options. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, activated by cytosolic mitochondrial DNA (mtDNA), has been increasingly implicated in UC. Through proteomics and artificial intelligence modeling, this study identified for the first time that senkyunolide I (SEI), a primary bioactive phthalide from Ligusticum striatum DC. (L. striatum), inhibits experimental colitis via the cGAS-STING pathway, with mechanistic validation performed in both intestinal tissues and cultured macrophages. Mutagenesis, activity-based protein profiling, and micro-scale thermophoresis reveal that SEI directly binds voltage-dependent anion channel 1 (VDAC1) at residue K12 to inhibit its stress-induced oligomerization. This blockade prevents mtDNA release into the cytosol, thereby suppressing the cGAS-STING cascade and subsequent M1 macrophage polarization, as well as downstream NLRP3 inflammasome activation, pyroptosis, and ferroptosis in macrophages and colon tissues. Overexpression of VDAC1-WT and VDAC1-K12A in mice confirms this mechanism. Clinically, VDAC1 expression in UC patients positively correlates with cGAS-STING activation and disease severity. Collectively, SEI alleviates colitis by targeting VDAC1 oligomerization to inhibit the cGAS-STING pathway in macrophages, establishing the VDAC1-cGAS-STING axis as a promising therapeutic strategy for UC.