The Protection Mechanisms Of Ginsenoside Rb1 On Human Umbilical Vein Endothelial Cells

Part I Inhibitory effect of ginsenoside Rb1 on busulfan-induced apoptosis in human endothelial cellsObjective To observe the busulfan-induced apoptosis in human endothelial cells and the effect of ginsenoside Rb1 on this type of apoptosis.Methods Human umbilical vein endothelial cells (HUVEC) were cultivated and divided into several groups randomly, which were administrated with busulfan at different concentrations for 12 or 24 hours to determine appropriate busulfan treatment dosage and duration. Then HUVEC were pre-incubated with ginsenoside Rb1 and subsequently exposed to busulfan. Apoptosis was detected by Flow Cytometry using Annexin-V assay.Results Busulfan at high concentration (120 mg/L) enhanced the ratio of the endothelial cells apoptosis. This apoptosis inducing effect was inhibited by ginsenoside Rb1, significantly distinctive in different dosage groups.Conclusion Busulfan at high concentration could initiate apoptosis in cultivated HUVEC, which could induce endothelium damage in hematopoietic stem cell transplantation. Ginsenoside Rb1 might protect endothelial cells by inhibiting busulfan-induce apoptosis.PartⅡEffect of ginsenoside Rb1 on busulfan-induced expression of plasminogen activator inhibitor-1,tissue factor and transforming growth factorβ-1 in human endothelial cellsObjective To investigate the busulfan-induced expression of plasminogen activator inhibitor-1(PAI-1),tissue factor(TF) and transforming growth factorβ-1(TGF-β1) in human endothelial cells and the effect of ginsenoside Rb1 on it, thus explore the protective mechanism of ginsenoside Rb1 on endothelial cells and determine appropriate Rb1 intervention dosage.Methods: HUVEC were cultivated and administrated with busulfan or ginsenoside Rb1. The endothelial PAI-1,TF and TGF-β1 mRNA expression and protein synthesis were detected by RT-PCR or real-time PCR and ELISA assay respectively.Results: HUVEC were divided into several groups randomly, which were administrated with busulfan at different concentrations for 24 hours to determine appropriate busulfan treatment dosage, and it was found that busulfan at 60 mg/L increased the PAI-1 and TGF-β1 mRNA expression obviously; then HUVEC were pre-incubated with ginsenoside Rb1 and subsequently exposed to busulfan, and it was found that the inducing effect of busulfan at 60 mg/L on endothelial PAI-1,TF and TGF-β1 mRNA expression and protein synthesis was inhibited by ginsenoside Rb1 at a certain concentration (80 [mg/L) significantly.Conclusion Busulfan may up-regulate the PAI-1 and TF expression in endothelial cells through TGF-β1-related signal transduction pathway which could enhance hypercoagulable and hypofibrinolytic state, thus induce hepatic veno-occlusive disease (HVOD) in hematopoietic stem cell transplantation (HSCT). Ginsenoside Rb1 shows a protective action on endothelial cells by inhibiting the overexpression of PAI-1 and TF. Ginsenoside Rb1 may provide beneficial effects on the prevention and treatment of HSCT-related complication HVOD.