The Effect Of Coixenolide On Inhibiting Aortic Vascular Smooth Muscle Cell Proliferation

Atherosclerosis (AS), the pathological foundation of many cardiovascular diseases, is one of the most important factors leading to cerebrovascular disease. Modern medical studies have proved that the main pathological feature of AS is the lipid deposition in the arterial wall, associated with the proliferation of vascular smooth muscle cells (VSMC) and fibrous stroma, resulting in the formation of atherosclerotic plaques after years of clinical course. Among them, the abnormal proliferation and migration of VSMC are not only the core pathological course of AS but also irreplacable link in the formation of atherosclerotic plaque and vascular restenosis. Therefore, effective control of the abnormal proliferation of VSMC is a crucial method for AS prevention.Coixenolide is one of the effective ingredients of Coix, with effects of anticancer, boost the immune system, regulating cell cycle and apoptosis, and is mostly used clinically in cancer treatment. Recent studies found that, through the mechanism of cell apoptosis, coixenolide can trigger death of many cancer cells. Hence, to inhibit the proliferation of VSMC through the characteristic of apoptosis induction by coixenolide will be a great help to AS prevention.Purpose:Using coixenolide to inhibit VSMC proliferation or induce VSMC apoptosis to attain the goal of AS prevention.Methods:Different concentrations of coixenolide diluents (0,5,10,20,40, 80, and 160μM) were added to human aortic vascular smooth muscle cells (HAVSMCs), incubated in 37℃incubator for 48 hours and observed under optical microscope to see the effect of coixenolide on HAVSMCs. Trypan blue assay was used to count the cell amount and conclude the relations between cell survival rate and coixenolide concentrations. At last, flow cytometry was used to examine the effect of coixenolide to cell cycle and apoptotic rate.Result:1. Coixenolide could actually affect HAVSMCs subsistence. Under the microscope, withered cells were observed, besides, nuclear appearance change, shrinkage, and condensed chromosome, were all characteristics of apoptosis.2. With higher coixenolide concentrations, the cell survival rate got lower. Cell viability was negatively correlated with the concentration. With coixenolide concentration of 10μM, the result showed significant difference in comparison to the control (P<0.05) and with concentrations higher than 20 ii M, the result showed highly significant difference to the control (P<0.01).3. The cell cycle analysis showed that as treating coixenolide, cell number decreased in Gl phase and increased in sub Gl phase. With higher concentrations of coixenolide, sub Gl phase cell number elevated, which means superior rate of apoptosis, suggested that coixenolide could induce cell apoptotic pathway instead of necrosis. Cell apoptosis rate was positively correlated with the concentration. With 10μM of concentration, the result showed significant difference (P<0.05) and with concentrations higher than 20μM, the result showed highly significant difference to the control (P<0.01).Conclusion:Coixenolide can indeed affect the survival rate of HAVSMCs and lead cells to death, probably through apoptosis. The research result showed that in addition to use in cancer, coixenolide could also be used in prevention to vascular sclerosis lesion development and provided further information and directions for Chinese medicine treatment of atherosclerosis prevention.