Qi Huoxue The Human Vascular Smooth Muscle Cell Proliferation

BackgroundSince the birth of percutaneous transluminal coronary angioplasty (PTCA), the percutaneous coronary intervention (PCI) has been playing an increasingly important role in the therapy for coronary heart disease. Nevertheless, the appearance of restenosis in the operation-expanded coronary artery occurs in some patients, to whom the restenosis has brought great economical and psychological burden. The major components in the mechanisms of restenosis (RS) post PTCA mainly include vascular elastic recoil, thrombus formation in the injured sites, excessive neointimal proliferation and negative vascular remodeling. And the excessive proliferation of vascular smooth muscle cell (VSMC), which is chiefly due to the secretion of growth factor and cytokines, contribute most to the neointimal proliferation. Therefore, studies of inhibiting VSMC proliferation have become a focus recently. Researchers have conducted a large number of studies on drug-eluting stent (DES), aiming at reducing the incidence of restenosis post PTCA. And they are also making effort on exploring novel stent to minimize the possibility of restenosis. The currently wide application of DES and new technologies is gradually showing a promising prospect for the tough situation, whereas not an omnipotent tactic for all restenosis. Moreover, problems such as high expenses, future therapeutic effects and safety await testification via clinical trials. Recent clinical and experimental studies show an excellent efficacy on inhibiting VSMC proliferation; therefore it is worthwhile to put research focus on the economic, safe Chinese herbs. The public consensus at present on diagnosing RS post PCI is involved in "chest stuffiness and pains".ObjectivesUnder the guidance of the Traditional Chinese Medicine (TCM) therapy, we perceive that the RS patients is featured the dual characteristics of "history of chest stuffiness and pains" and consumption of Qi and blood due to "exterior catheter mechanical contusion". That the "Qi deficiency and blood stagnation" goes through the onset and pathological evolution of RS process induces us to deduce that the therapeutic principle-—"supplementing Qi and activating blood circulation"—weighs very much in prevention and treatment of RS. According to the respective understanding of TCM and western medicine on the mechanisms of RS, we refined 3 Chinese herbs, reported as functioning in inhibiting proliferations of VSMC and artery tunica intima after endothelium denudation, increasing coronary blood flow, with the effect of "supplementing Qi and activating blood circulation", to form a simple compound prescription—Yiqi Huoxue(YQHX) prescription, observing the in vitro effects of it and its functionally divided prescriptions (Yiqi prescription, Huoxue prescription) on human VSMC proliferation, so as to explore how YQHX prescription effects human VSMC.MethodsHuman VSMC was cultured with serum pharmacology, growing status observed with MTT method, cell cycle distribution determined with flow cytometry (FCM), through all of which the effects of YQHX prescription and its functional divided prescriptions medicated serum on human VSMC proliferation and cell cycle were observed. All data were analyzed with one-way ANOVA (analysis of variance) and Mest.Results(1)On MTT: Huangqi Group, Huoxue Group and YQHX Group showed obvious lower OD value than that of Control Group, with extremely significant differences (P<0.01); and, the same significance was observed in comparisons among groups except Control Group: the lower OD value of Huoxue Group than other 2 medicated groups (P<0.01).(2)On FCM: Proportion of cells in G₀/G₁ stage was much greater in the 3 medicated groups than in Control Group (P<0.01); the number of cells in G₂/M stage was showed obvious increased only in YQHX Group (P<0.05), whereas with an apparent decrease in cells in S stage. Comparisons among the medicated groups demonstrated a highest proportion of G₀/G₁ stage cells and a smallest ratio of S stage cells in Huoxue Group, with extremely significant differences statistically (P<0.01).ConclusionsYQHX prescription and its functionally divided prescriptions (Yiqi prescription and Huoxue prescription) medicated serum function in inhibiting proliferation of human VSMC and DNA synthesis to cease the cell growth at G₀/G₁ stage. Moreover, the among-group comparisons within medicated groups suggest that the best inhibitive effect on VSMC proliferation belongs to Huoxue prescription.