Crocin alleviates coronary atherosclerosis via inhibiting lipid synthesis and inducing M2 macrophage polarization.

Atherosclerosis is a chronic inflammatory disease arising from an imbalance in lipid levels and the accumulation of cholesterol-laden macrophages in the artery wall. Crocin is an active ingredient of Crocus sativus L. This study established a rat coronary atherosclerosis model induced by vitamin D3 (VD3), to explore the effect of Crocin on lipid metabolism, macrophage polarization and the activity of inflammatory proteins. The results revealed that Crocin decreased blood lipid levels by decreasing the levels of endothelin (ET), total cholesterol (TC), triglyceridelow (TG) and low-density lipoprotein cholesterol (LDL-c), elevating the level of high-density lipoprotein cholesterin (HDL-c). Crocin also inhibited lipogenesis by suppressing the expression of lipogenesis-related proteins and elevating lipid catabolism-related proteins. Moreover, Crocin effectively alleviated inflammation by suppressing the expression of pro-inflammatory cytokines and increasing levels of anti-inflammatory cytokines. We further found that Crocin promoted macrophage polarization to the M2 phenotype by reducing M1 markers (CD40 and CD11c) and elevating M2 markers (CD68 and CD206). Finally, Crocin strongly inhibited the expression of NF-κB p65 and its translocation into the nucleus. Crocin partially counteracted nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 expression and the nuclei accumulation caused by NF-κB p65 overexpression. Taken together, our research indicated that Crocin inhibited lipogenesis and alleviated the inflammation in a VD3-induced rat coronary atherosclerosis model by promoting M2 macrophage polarization and maybe by inhibiting NF-κB p65 nuclear translocation. This study implicates Crocin as a potential therapeutic strategy for coronary atherosclerosis.