摘要Objective:To observe the effect of extracts from Radix Ginseng,Radix Notoginseng and Rhizoma Chuanxiong (EXT) on delaying vascular smooth muscle cells (VSMCs) aging in aged rats.Methods:VSMCs were obtained by the modified tissue explants technique and were shown to be positive for smooth muscle α-actin (SM-α-actin) by immunohistochemistry staining.VSMCs obtained from the young rats were served as the young control group; VSMCs obtained from the old rats were treated with no drug (the old group),with low dose extracts (20 mg/L,the EXT low-concentration group) and high dose extracts (40 mg/L,the EXT highconcentration group),and with Probucal (10-6 mol/L,the Probucal group) as a positive control.All groups were cultured for 24 h in the medium with 10％ serum for 24 h followed by another 24 h in the serum-free medium.At the end of the 48-h culture,the following analyses were performed including determination of senescenceassociated β -galactosidase (SA β -Gal) activity,flow cytometry analysis of cell cycle,real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) analyses of p16,Cyctin D1,cyclin-dependent Iinase 4 (CDK4)and retinoblastoma (Rb) mRNA expression,and Westem blotting analyses of p16,cyclin D1,CDK4 and phosphoretinoblastoma (pRb) protein expressions.Results:(1) In comparison to the younger rats,VSMCs from aged rats had significantly more SAβ-Gal positive cells (P＜0.01) and more cells in S phase (P＜0.05).VSMCs from the all treated groups showed a significant decrease in both SA β-Gal positive cells (P＜0.05) and S phase (P＜0.05) compared to the old rats.(2) Compared with the young group,VSMCs in the old group had a significant decrease in p16 and Rb mRNA expression and a significant increase in Cyclin D1 and CDK4 mRNA expression.Compared with the old group,VSMCs in the treated groups had a significant increase in p16 and Rb mRNA expression and a significant decrease in Cyclin D1 and CDK4 mRNA expression (P＜0.05).(3) Compared with the young group,VSMCs in the old group had a significant decrease in p16 protein expression and a significant increase in Cyclin D1,CDK4 and pRb protein expressions (P＜0.05).Compared with the old group,VSMCs in the treated groups had a significant increase in p16 protein expression and a significant decrease in cyclinD1,CDK4 and pRb protein expressions (P＜0.05).Conclusions:VSMCs obtained from old rats showed typical signs of cellular senescence and vascular aging.EXT had an effect on delaying senescence of VSMCs in vitro by altering the p16-cyclinD/CDK-Rb pathway.