AimThe aim of this study was to investigate the relation of traditional Chinese drug Dan Hong, C-reactive protein (CRP) and matrix metalloproteinase-1 (MMP-1).MethodsHuman THP-1 cells were induced to differentiated into macrophages with phorbol-12 myristate 13-acetate (PMA).Enzyme-linked immunosorbent assay (ELISA) was used to determine the macrophages secretes MMP-1 in peak time.Thereafter, cells were divided into three groups: control group, CRP group, Dan Hong injection group, ELISA was applied to test the MMP-1 concentration in the cell supernatant of three groups, and then MMP-1 mRNA expression at different time was tested by reverse transcription polymerase chain reaction (RT-PCR) in CRP group.At last, the protein concentration and mRNA expression of MMP-1 were analyzed.ResultsTHP-1 cell induction into macrophages was observed under the microscope, the peak of MMP-1 secretion was in 24-hour.Compared with the control group, protein and mRNA expression of MMP-1 in CRP group was up-regulated gradually with 5 mg/L, 10 mg/L, 25 mg/L, 50 mg/L CRP.The result exposed that MMP-1 level was markedly elevated in a concentration dependent fashion (p<0.05).Compared with the control group, MMP-1 ex-pression in Dan Hong injection group was lower than the control group.MMP-1 expression in Dan Hong injection group was down-regulated segmentally and dependently with 200 mL/L, 400 mL/L, 800 mL/L, 1 600 mL/L, 3 200 mL/L Dan Hong injection, but MMP-1 expression by Dan Hong injection intervention has no significance whether with CRP (50 mg/L) or not (p>0.05).ConclusionsCRP promotes the expression of MMP-1 in THP-1 derived macrophages.Dan Hong can attenuate the MMP-1 secretion in interval, and there was no difference with or without CRP.