Abstract

Objective Acute pancreatitis (AP) is a potentially life-threatening inflammatory disease with limited therapeutic options. Honokiol has shown beneficial effects in animal models of AP, its mechanisms involving mitochondrial activity remain poorly understood. This study investigated whether honokiol protects against AP by activating the mitochondrial deacetylase sirtuin 3 (SIRT3) and regulating oxidative phosphorylation (OXPHOS) function. Methods A mouse model of caerulein-induced AP was established to assess the temporal expression of SIRT3 and the effects of its pharmacological inhibition. The efficacy of honokiol was evaluated in vivo using a AP mouse model and in vitro using 266-6 cells and primary pancreatic acinar cells. Proteomic analysis was performed to identify SIRT3-regulated mitochondrial proteins and pathways. Protein–protein docking and immunoprecipitation were used to validate the interaction and acetylation of the respiratory complex subunits. Results SIRT3 expression was markedly reduced in AP, while its inhibition exacerbated disease severity, confirming a protective role. Honokiol treatment restored SIRT3 expression, alleviated inflammation and mitochondrial damage, and partially rescued OXPHOS protein expression. The proteomic profiling identified three candidate OXPHOS subunits—adenosine triphosphate synthase membrane subunit K, cytochrome c 1 (CYC1), and ubiquinol-cytochrome c reductase hinge protein—that were restored by honokiol treatment. The protein–protein docking analysis revealed strong binding affinity between SIRT3 and CYC1. The immunoprecipitation assay further confirmed that honokiol reduced the acetylation of CYC1, indicating that this effect is mediated by SIRT3 activity. Conclusion Honokiol activates SIRT3 and promotes deacetylation of the respiratory complex Ⅲ subunit CYC1, contributing to OXPHOS restoration and mitochondrial pro