Harpagide Increases microRNA-140-5p Expression to inhibit Oxidised Low-Density Lipoprotein-Caused Human Umbilical Vascular Endothelial Cell Damage

To investigate the influence of harpagide isolated from Scrophularia ningpoensis Hemsl. on human umbilical vascular endothelial cells damage induced by oxidized low-density lipoprotein and its possible mechanism. Human umbilical vascular endothelial cells were cultured in vitro. Different doses (20, 40, 80 μmol/l) of harpagide were applied to treat human umbilical vascular endothelial cells induced by oxidized low-density lipoprotein, human umbilical vascular endothelial cells overexpressing microRNA-140-5p were induced by oxidized low-density lipoprotein, and 80 μg/ml harpagide was applied to treat oxidized low-density lipoprotein induced human umbilical vascular endothelial cells with microRNA-140-5p downregulation. Enzyme-linked immunosorbent assay kits were used to detect malondialdehyde content as well as superoxide dismutase and glutathione peroxidase activities. Flow cytometry and Western blot were utilized to investigate cell apoptosis. Ribonucleic acid expression was analyzed by real-time quantitative reverse transcription polymerase chain reaction. Different doses of harpagide (20, 40, 80 μmol/l) reduced the malondialdehyde content and the rate of apoptosis in oxidized low-density lipoprotein-stimulated human umbilical vascular endothelial cells (p<0.05), while elevated superoxide dismutase as well as glutathione peroxidase activities (p<0.05). MicroRNA-140- 5p overexpression reduced the malondialdehyde content and apoptosis in oxidized low-density lipoproteinstimulated human umbilical vascular endothelial cells while elevated superoxide dismutase as well as glutathione peroxidase activities (p<0.05). Harpagide promoted microRNA-140-5p expression in human umbilical vascular endothelial cells after oxidized low-density lipoprotein stimulation (p<0.05). MicroRNA- 140-5p knockdown reversed the inhibitory effect of harpagide in human umbilical vascular endothelial cells (p<0.05). Harpagide up-regulates microRNA-140-5p to inhibit the oxidative stress and apoptosis of oxidized low-density lipoprotein-induced human umbilical vascular endothelial cells.