Fenchone alleviates 7-ketocholesterol-induced oxiapoptophagy through activation of KLF4-PPARγ-Arg1-mediated M2...

7-ketocholesterol (7KCh), a cytotoxic oxysterol enriched in atherosclerotic plaques, provokes macrophage dysfunction through oxiapoptophagy, a linked process of oxidative stress, apoptosis and autophagy culminating in pro-inflammatory M1 polarization. Targeting this process could mitigate oxysterol-driven vascular inflammation. In this study, murine IC-21 macrophages were induced with 7KCh and co-exposed to fenchone, a bicyclic monoterpene with known anti-inflammatory properties. Cellular oxidative stress, apoptosis and autophagy were assessed by spectrofluorometric and cytometric assays. Expression of key mediators (iNOS, COX2, HO1, Casp3, Bcl2, LC3B, PARP1, Arg1, KLF4 and PPARγ) was quantified by RT-qPCR and western blotting. Molecular docking was used to identify interactions of fenchone with KLF4 and PPARγ. The results showed that 7KCh significantly increased ROS and NO production, disrupted mitochondrial membrane potential and induced apoptosis and autophagy in macrophages. Fenchone co-treatment counteracted these effects, restoring redox balance and membrane integrity. Molecular analyses revealed downregulation of iNOS, COX2, Casp3 and PARP1, alongside upregulation of HO1, Arg1, KLF4 and PPARγ. Docking analysis confirmed strong binding of fenchone to KLF4 and PPARγ, suggesting transcriptional regulation of macrophage polarization via the KLF4-PPARγ-Arg1 axis. These findings suggest that fenchone mitigates 7KCh-induced oxiapoptophagy and reprograms macrophages toward an anti-inflammatory M2 phenotype through modulation of KLF4/PPARγ signalling, positioning fenchone as a potential immunomodulatory candidate for combating oxysterol-mediated vascular inflammation.