Effect Of Paeoniflorin On Vascular Endothelial Cell Injury By Oxidized Low-density Lipoprotein In Vitro And Its Mechanism

Objective: To investigate the protective effect of paeoniflorin（PF）on injury of HCAECinduced by ox-LDL through the detection of a variety of indicators. To study the effects of PF inatherosclerosis and the possible mechanism of its antiatherosclerosis．Methods:①the effect of different concentrations of ox-LDL on HCAEC: we treatedHCAECs with different concentrations of ox-LDL(25μg/ml,50μg/ml,100μg/ml and200μg/ml) andobserved the injury of cells by MTT assay and staining of Hoechst33342/PI.②HCAECs wereincubated with different concentrations of PF（50μg/ml,100μg/ml and200μg/ml）for24h and theviability of cells was detected by MTT assay. HCAECs were incubated with different concentrations ofPF（50μg/ml,100μg/ml and200μg/ml）and100μg/ml ox-LDL. The protective effect of differentconcentrations of PF on the injury of HCAEC were checked, the viability of cell was detected by MTTassay；The cell apoptosis rate was investigated by staining with Hoechst33342/PI under Fluorescencemicroscopy；SOD activity, LDH activity and MDA content were assayed by respective kits. ROS andNO content were assayed by fluorescent probes. The expression of ICAM-l mRNA and VCAM-1mRNA were measured by RT-PCR．Results: Ox-LDL could increase the apoptosis rate of HCAEC and decrease the viabilitycompared with the control group(P<0.01). These effects induced by ox-LDL were significantly inhibitedby PF. PF can decrease the extent of HCAEC damaged by ox-LDL；PF can diminish the level of MDAand LDH but increase the level of SOD produced by the injury of HCAEC；PF can both increase thecontent of NO and decrease the content of ROS. Higher level of ICAM-1and VCAM-1mRNAexpression induced by ox-LDL was detected by RT-PCR compared with the control group(P<0.01)．After treatment with PF, The expression of ICAM-1and VCAM-1mRNA wasreduced(P<0.01)．Conclusions:(1) ox-LDL could induce the injury of endothelial cells.(2) PF could decrease the injury of endothelial cells induced by ox-LDL.(3) PF could inhibit the expressions of ICAM-1and VCAM-1mRNA induced by ox-LDL.That may be one of the mechanisms of antiatherosclerotic effect of PF.(4) PF can both decrease the ROS level and increase the NO level. PF may protect theendothelial cells and decelerate the progression of atherosclerosis.