Atherosclerosis (AS) is the pathological basis of multiple cardiovascular diseases. The pathogenesis of AS is closely related to the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). Nuciferine, an aporphine alkaloid from lotus leaf, has various pharmacological activities. However, the effect and mechanism of nuciferine on regulating proliferation and migration of VSMCs against AS is still unclear.To elucidate the pharmacological effect and molecular mechanism of nuciferine on AS in ApoE(-/-) mice fed with High-Fat-Diet (HFD).HFD-fed ApoE(-/-) mice and 3% fetal bovine serum (FBS) induced mouse aortic vascular smooth muscle cells (MOVAS) were used to investigate the protective effect and mechanism of nuciferine on AS.Oil red O staining was used to detect the atherosclerotic lesions. Western blotting and immunofluorescence were used to determine calmodulin 4 (Calm4) expression and localization. CCK-8 assay, transwell and wound-healing assays were used to measure the migration and proliferation of MOVAS cells.Nuciferine at 40 mg/kg significantly ameliorated the aortic lesion and vascular plaque in AS model, which was equal to the effect of the positive control drug (atorvastatin). In addition, nuciferine attenuated the migration and proliferation of VSMCs in vivo and in vitro. Importantly, nuciferine down-regulated the increase of Calm4 induced by HFD-fed in ApoE(-/-) mice or 3% FBS induced MOVAS cells. However, the inhibitory effect of nuciferine on the migration and proliferation of MOVAS cells was blocked when Calm4 was overexpressed. Furthermore, we found that nuciferine suppressed MMP12 and PI3K/Akt signaling pathway via Calm4.Our results illustrated that Calm4 promoted the proliferation and motility of MOVAS by activating MMP12/Akt signaling pathway in AS. Nuciferine has a significant anti-atherogenic effect by regulating the proliferation and migration of VSMCs through the Calm4/MMP12/AKT signaling pathway. Thus, Calm4 could potentially be a new target for AS therapy, and nuciferine could be a potential drug against AS.Copyright © 2022. Published by Elsevier GmbH.