MCL inhibits macrophage ferroptosis through the NRF2/HO-1/GPX4 axis to attenuate carotid atherosclerotic plaque formation

Background: Micheliolide (MCL) exhibits strong antioxidant and anti-inflammatory properties. Carotid atherosclerotic plaques are a key risk factor for ischemic stroke. This study investigates MCL's protective effects on carotid atherosclerosis and its mechanism.

Methods: In vitro, RAW264.7 macrophages were transformed into foam cells using ox-LDL. After treatment, oxidative stress, mitochondrial function, ferroptosis-related proteins, and NRF2 activation were assessed. MCL's anti-ferroptosis effect was tested with the Ferroptosis inhibitor Fer-1 and inducer Erastin. In vivo, a carotid atherosclerosis model in ApoE-/- mice was created using the silicone collar method. Mice were divided into normal, high-fat diet, MCL, and atorvastatin calcium control groups. Plaque area, Collagen content, blood lipids, inflammatory factors, and oxidative stress indicators were measured.

Results: In vitro experiments demonstrated that MCL intervention significantly inhibited lipid droplet formation, improved mitochondrial function, reduced oxidative stress, and upregulated the expression of HO-1 and GPX4, thereby mitigating ox-LDL-induced Ferroptosis in macrophages. The anti-ferroptosis effect of MCL was comparable to that of Fer-1 and effectively reversed Erastin-induced cell death. MCL facilitated NRF2 nuclear translocation, and the application of si-NRF2 markedly diminished the cytoprotective and antioxidant effects of MCL, confirming its dependence on NRF2. In vivo experiments indicated that MCL significantly reduced plaque area, increased Collagen fiber content, alleviated inflammation, and ameliorated lipid disorders, exhibiting effects akin to those of atorvastatin calcium.

Conclusion: MCL inhibits macrophage Ferroptosis through activation of the NRF2-HO-1-GPX4 pathway, providing a protective effect against atherosclerotic vessels. This effect is dependent on NRF2.