Effect Of Salvianolate On Radiation Damage To Vascular Endothelial Cells

Objectives:To observe the effect of salvianolate on proliferation, production of superoxide dismutase(SOD) and malonic aldehyde(MDA), and apoptosis induced by ionizing radiation in human umbilical vein endothelial cells (HUVECS), and to investigate the potential mechanisms involved.Methods:1. HUVECS-ECV304 were cultured in vitro.2. According to the requirement of the experiment, ECV304 cells were grown in either flasks or plates. Two days later when these cells reached the logarithmic growth phase, new culture medium containing salvianolate(at 0, 0.5, and 1.0mg/l) were used to incubate the cells. ECV304 cells were divided into 3 groups: control, salvianolate at 0.5 mg/l and 1.0mg/l concentrations respectively.3. Every group of cells was irradiated with a single dose of either 8Gy or 16Gy 6MV-X ray. Following irradiation,cells were maintained in growth medium for 24 hours.4. Proliferation of ECV304 cells was assessed by 3-(4,5-dimethylthiazol- 2-yl)- 2-5- diphenyl-tetrazolium bromide(MTT) assay before irradiation and 24 hours later. The activity of SOD and the contents of MDA were assessed by chemical colorimetry assay. The rates of apoptosis were detected by flow cytometry.Results:1. After ECV304 cells were irradiated with a single dose of either 8Gy or 16Gy 6MV-X ray, celluar proliferation was inhibited. Compared with 8Gy 6MV-X ray, in the control groups, the inhibition ratio of 16Gy increased significantly(P<0.0001), and MDA concentration in the supernatant increased significantly as well(P<0.001). While the activity of SOD decreased significantly(P<0.0001), the rates of apoptosis also increased significantly (P<0.001).2. Compared with the control groups,salvianolate(at 0.5 and 1.0mg/l) could significantly decrease the inhibition ratio(P<0.0001) induced by irradiation and the contents of MDA(P<0.001) in the supernatant. It can significantly increase the activity of SOD(P<0.0001) while decreasing the rates of celluar apoptosis(P<0.001). Furthermore, the effect is related to the concentration of salvianolate.Conclusions:1. Ionizing radiation can injure HUVECS, inhibit cell proliferation, reduce the activity of SOD, increase the contents of MDA, and induce their apoptosis. Ionizing radiation may cause injury to endothelial cells via inhibition of cell proliferation, activation of oxidative stress and apoptosis.2. Salvianolate can significantly decrease the inhibition ratio of endothelial cells, increase the activity of SOD, decrease the contents of MDA, and reduce celluar apoptosis induced by irradiation. These may help explain the protective effects salvianolate shows on vascular endothelial cells damaged by ionizing radiation.