In this study,we examined the protective effects of Danshen both on endothelial progenitor cells(EPCs) in patients with hypercholesterolemia and on in-vitro EPCs of healthy volunteers.In the clinical study,we randomly divided 24 subjects with hypercholesterolemia into two groups(the control group and the Danshen-treated group).At the end of two weeks of treatment,the EPC cellular functions of both groups were tested.The results indicated that,compared to the control group,EPCs in the Danshen-treated group showed significantly better cellular functions,which was manifested in the cloning number,the proliferation capacity,the number of EPC adhesions,and cell migration.In the subsequent in-vitro experiments,EPCs were treated with vehicle,oxidized low-density lipoprotein(Ox-LDL,100 μg/ml),or Ox-LDL(100 μg/ml) plus different concentrations of Danshen(Danshensu 2,10,or 50 μg/ml,respectively) for 24 h.The results showed that Danshen treatments can prevent the detrimental effects of Ox-LDL on EPC cellular functions measured by proliferation capacity(0.24±0.08,0.37±0.11,0.30±0.04 vs.0.13±0.02,P<0.05,P<0.01,and P<0.01,respectively),and adhesion ability(63.00±11.60,70.00±10.80,85.50±11.41 vs.40.50±6.85,all P<0.01).Compared to the group treated with Ox-LDL alone,Danshen treatment significantly decreased the lipid peroxidation end product malondialdehyde(MDA) [(4.34±0.54),(3.98±0.47),(3.46±0.31) vs.(5.57±0.64) nmol/ml,all P<0.01],increased the production of superoxide dismutase(SOD) [(29.74±0.71),(31.09±0.83),(30.41±0.65) vs.(14.76±3.99) U/ml,all P<0.01],and lowered the expression of interleukin-6(IL-6) [(24.62±7.69),(27.04±3.14),(33.38±18.86) vs.(230.67±33.53) pg/ml,all P<0.01] and tumor necrosis factor-α(TNF-α) [(41.72±6.10),(17.02±6.82),(3.73±2.26) vs.(228.71±41.53) pg/ml,all P<0.01] in Ox-LDL treated EPCs.These results suggest that Danshen may exert a protective effect through its antioxidant and anti-inflammatory features. In this study, we examined the protective effects of Danshen both on endothelial progenitor cells (EPCs) in patients with hypercholesterolemia and on in-vitro EPCs of healthy volunteers. In the clinical study, we randomly divided 24 subjects with hypercholesterolemia into two groups (the control group and the Danshen-treated group). At the end of two weeks of treatment, the EPC cellular functions of both groups were tested. The results indicated that, compared to the control group, EPCs in the Danshen-treated groups showed significantly better cellular functions, which was manifested in the cloning number, the proliferation capacity, the number of EPC adhesions, and cell migration. in subsequent in-vitro experiments, EPCs were treated with vehicle, oxidized low-density lipoprotein μg / ml) or Ox-LDL (100 μg / ml) plus different concentrations of Danshen (Danshensu 2, 10, or 50 μg / ml, respectively) for 24 h. The results showed that Danshen treatments can prevent the detrimental effects of Ox-LDL on EPC cellular functions measured by proliferation capacity (0.24 ± 0.08,0.37 ± 0.11,0.30 ± 0.04 vs0.13 ± 0.02, P <0.05, P <0.01, and P <0.01, respectively) and adhesion ability (63.00 ± 11.60, 70.00 ± 10.80,85.50 ± 11.41 vs.40.50 ± 6.85, all P <0.01) .Compared to the group treated with Ox-LDL alone, Danshen treatment significantly decreased the lipid peroxidation end product malondialdehyde (MDA) [(4.34 ± 0.54), The production of superoxide dismutase (SOD) [(29.74 ± 0.71), (31.09 ± 0.83), P <0.01] was significantly higher than that of the control group (3.98 ± 0.47, (30.41 ± 0.65) vs. (14.76 ± 3.99) U / ml, all P <0.01], and lowered the expression of interleukin-6 (IL-6) [(24.62 ± 7.69), (27.04 ± 3.14), (33.38 ± 18.86 vs. 230.67 ± 33.53 pg / ml, all P <0.01] and tumor necrosis factor-α (TNF-α) [(41.72 ± 6.10), (17.02 ± 6.82), (3.73 ± 2.26 vs. (228.71 ± 41.53) pg / ml, all P <0.01] in Ox-LDL treated EPCs. These results suggest that Danshen may exert a protective effect through its antioxidant and anti-inflammatory features.