In vitro effects of selected angiogenesis-promoting drugs on human Ea.hy926 endothelial cells treated with critical-stage dengue hemorrhagic fever serum

Endothelial dysfunction is the major pathophysiological effect in severe dengue infection. The effects of three angiogenesis-promoting drugs, Simvastatin, Phenytoin, and Ascorbic acid on endothelial dysfunction was assessed using the simulation model using Ea.hy.926 cells treating with severe dengue hemorrhagic fever serum. Sera of patients with dengue fever (DF, n=5), dengue hemorrhagic fever (DHF, n=5), and healthy controls (HC, n=5) were treated on Ea.hy926 endothelial cells and distances were measured after 3-hour incubation. DHF-treated cells showed a significant increase in average cell-cell distances compared to HC and DF, simulating endothelial destabilization caused during DHF condition (p<0.05). Significant reductions in cell-cell distances were observed in the cells treated with 0.01 µM and 1 µM Simvastatin along with DHF serum, compared to the cells treated only with DHF serum (p<0.05). Among these two conditions tested, 0.01 µM Simvastatin showed a significant reduction in the cell-cell distances (p<0.05) and a significant increase in cell sizes (p<0.05) in the presence of DHF serum. Ascorbic acid (40 µM, 80 µM) showed no significant effect towards the endothelial monolayer destabilization in the presence of DHF serum. Both concentrations of phenytoin (10 µM, 30 µM) showed a significant increase in the average cell-cell distances compared to cells treated with DHF (p<0.05). This preliminary study suggests that low-dose Simvastatin promotes endothelial membrane formation in the presence of DHF serum and the reduction in cell-to-cell distances may not due to cell proliferation but could mainly be due to the increase in the average cell size, a known effect of Simvastatin.