AimTo investigate the effect of nuciferine on scavenger receptor class B type Ⅰ(SR-BⅠ) expression and foam formation in human THP-1 derived macrophage induced by oxidized low density lipoprotein (ox-LDL), and probe the possible mechanism of nuciferine in anti-atherosclerosis.Methods After the establishment of monocyte lines THP-l -derived foam cell, these foam cells were treated with nuciferine at different concentrations（0, 25, 50, 100 mg/L）for 24 h.The effect of nuciferine on foam cell was observed by oil red O staining; the levels of SR-BⅠ mRNA and protein were measured by RT-PCR and Western Blot, respectively.ResultsCompared with control group, lipid droplets was increased while mRNA (1.00±0.00, 0.53±0.04, 0.30±0.04, 0.18±0.03）and protein（1.00±0.00, 0.62±0.10, 0.39±0.08, 0.22±0.05）expression of SR-BⅠ were downregulated in ox-LDL groups in a dose-dependent manner (p<0.01); after the intervention of nuciferine, lipid droplets was decreased while mRNA (0.32±0.02, 1.07±0.02, 1.28±0.03, 1.49±0.03）and protein（0.28±0.03, 1.06±0.02, 1.32±0.03, 1.41±0.02） expression of SR-BⅠ were upregulated in a dose-dependent manner (p<0.01).ConclusionNuciferine upregulates SR-BⅠ expression in THP-1 derived macrophages, lessen the degree of foam formation.We probe that this may be the possible mechanism of nuciferine in anti-atherosclerosis.