The Protective Effect Of Berberine Against Oxidized LDL Induced-injuries On Endothelium Cells

ObjectiveTo explore whether berberine has the protective effects on endothelial cells, and the possible mechanism.MethodsThe human umbilical vein endothelial cells (HUVECs) CRL1730 were resuscitated and cultured in DMEM medium with 15% newborn calf serum. The HUVECs were divided into five groups: control group, model group (which was treated with 300mg/L ox-LDL), pretreated with different concentrations of berberine (25,50,100μmol/L). The culture condition in control group and model group was DMEM medium with 15% newborn calf serum and without berberine, and the pretreated groups were DMEM medium with 15% newborn calf serum, containing different concentrations of berberine for 4 hours. And then, the culture condition in model group and pretreated groups were altered from the primary medium to DMEM medium which contain 300mg/L ox-LDL for 24 hours. The cells modality were observed under inverted phase contrast microscope. The cell viability rate were detected by MTT. The content of NO and ET-1 in cells culture medium were measured by nitrate reductase method and radio-immunity technique. The eNOS mRNA expression in cells were measured with RT-PCR. The levels of eNOS protein in cells were measured by western blotting.ResultsCompared with control group, HUVECs showed the characteristical of round shape, broaden intercellular boundary, had granular cytoplasm and round vaculation after treatment with ox-LDL. And cells viability was inhibited (P <0.01). The levels of eNOS mRNA and eNOS protein not only were obviously decreased, but also the contents of NO were reduced in HUVECs treated with ox-LDL (P<0.01). Simultaneously, the ET-1 levels in HUVECs treated with ox-LDL were obviously increased (P<0.01).Compared with model group, the characteristical of HUVECs was restored, or even showed normal shapes after pretreatment with berberine. And cell viability was increased (P<0.05). Furthermore, not only the levels of eNOS mRNA and eNOS protein, but also the contents of NO were obviously increased in HUVECs pretreated with berberine(P<0.01). Simultaneously, the ET-1 levels in in HUVECs treated with ox-LDL were obviously decreased (P<0.01).After pretreated with berberine, the cells viability firstly increased, then reduced gradually with the concentrations of berberine augmented gradually. Simultaneously, the changes of eNOSmRNA, eNOS protein and NO levels showed the characteristical of increase in HUVECs pretreated with low concentration of berberine, then decrease with high concentration of berberine(P<0.05).Furthermore, the levels of ET-1 showed firstly the increase, then the decrease characteristical with the gradually augmented concentrations of berberine(P< 0.05).Conclusions300mg/Lox-LDL can significantly inhibit and even kill the endothelial cells, and it can up-regulation the levels of ET-1, and it can down-regulation the levels of NO,eNOSmRNA and eNOS protein. Berberine can protect the endothelial cells against the ox-LDL-induced injuries. The mechanism of this protective effect may because berberine can inhibit the ox-LDL-induced eNOSmRNA,eNOS protein low expression. This results provid the foundation for the farther research and application of berberine in atherosclerosis'prevention and cure.