Objective: To study the effect of Aloe-emodin (AE), an active ingredient of Rhubarb, on the kinetics of proliferation of smooth muscular cells (SMCs) cultured in vitro after rabbit iliac arterial injury.
Methods: Forty-eight hours after de-endothelialization (balloon endothelial denudation), the iliac arteries of the Japanese white rabbits were isolated and the smooth muscle cells were cultured primarily. AE was added to culture medium containing 10% fetal calf serum (FCS). The cultures were pulse-labeled with 3H-TdR and TdR uptake into VSMC were measured and the cell cycle of the cultures were analyzed by using flow cytometer.
Results: Compared with control, when the concentration gradient ranged from 10(-1) to 10(-5) g/L, the amount (cpm, count per minute) of 3H-TdR uptake into SMCs has significant differences (P < 0.05) and 10(-1) and 10(-2) g/L AE showed strong inhibitory effects on TdR uptake into VSMC and the percentage of inhibition [% inhibition = (cpm without AE - cpm with AE)/cpm without AE x 100%] was more than 90%. AE displayed concentration dependent inhibitory effects. The percentage of cells in G0/G1 phase was increased, but the percentage of cells in S phase was decreased in AE group, the transition of SMC cycle phase from G0 to S was blocked.
Conclusions: AE is a strong inhibitor to the proliferation of SMCs and the pharmacological action of AE might reduce SMC proliferation in vivo and decrease intimal hyperplasia of restenosis.