Objective Tongxinluo(TXL) is a traditional Chinese herbal medicine with multiple biological activity.Dendritic cells(DC),which are professional antigen-presenting cells,were recently detected in atherosclerotic plaques.It is assumed that DC plays a critical role in the immunological processes related to atherosclerosis.Thus,we investigated the effects of TXL on atherosclerosis by affecting the maturation of DC.Methods Human monocyte-derived DC were incubated with TXL(200 μg/ml) for 24 h,and were subsequently stimulated with oxidized-LDL(50 μg/ml)for another 48h to induce maturation.The immunophenotypic expressions(including CD1 a,CD40,CD86,HLA-DR) and the endocytosis function were analyzed by FACS,the cytokines secretions of culture supernatants(IL-12,IL-10 and TNFα) were measured with ELISA.Results Compared with ox-LDL group,TSPG pre-incubated DC exhibited a significantly lower expression of the maturation-associated markers CD40,CD86,HLA-DR,and CD1a.(the mean fluorescence intensity(MFI) were47.88 ±2.53 versus 80.41 ±4.28,10.27 ±3.75 versus 48.56 ± 13.79,20.58 ±1.73 versus 23.17 ±3.87,59.01 ±10.99 versus 98.84 ± 11.82.)increased endocytosic function(59.69 ± 5.39 versus 31.1 ± 1.75) and decreased cytokine secretionslL-10,TNF-α,IL-12(95.57 ± 16.47 versus 135.83 ± 16.71,58.32 ±12.37 versus 118.85 ± 18.04,42.53 ± 22.42 versus 100.17 ±27.81).Conclusion In the present study,we suggested that TXL could inhibit the maturation of dendritic cells induced by oxidized-LDL,thus maybe contribute to their beneficial effects in atherosclerosis.