The Study Of Naringin Inhibiting Homocysteine-induced Apoptosis Of Human Umbilical Vein Endothelial Cells

Objective Homocysteine(Hcy) has been identified as an independent risk factor for atherosclerosis. It may cause atherosclerosis through damage the function of vascular endothelium, promotion the formation of artery thrombus, promotion the proliferation of vascular smooth muscle, promotion the accumulation of platelet and influence lipid metabolism. But the mechanism is not very clear. Current study was investigated whether naringin(NG) inhibit homocysteine-induced apoptosis and atherosclerosis.Method The human umbilical vein endothelial cells(HUVEC) in logarithmic growth phase were used after subculturing in vitro. Different concentrations (1,3,5 mmol/L) of Hcy were added in HUVEC, and the optimal concentration and effective duration of Hcy induced HUVEC apoptosis were taken. Different concentrations of naringin with different duration were used to identify the drug concentration and duration of Hcy induced HUVEC apoptosis. Cell viability was checked by MTT assay. The cell morphology was observed by acridine orange and bromide staining. DNA ladder was detected by DNA gel electrophoresis and the apoptosis rate was assayed by flow cytometry. Result MTT results showed that 3mmol/L and 5mmol/L of Hcy in HUVEC can reduce cell viability to 48.57% (P<0.05) and 38.65% (P <0.05) compared with control, respectively. 5mmol/L Hcy with 300umol/l naringin caused the cell viability increased to 86.81% (P <0.05), 500umol/l naringin caused the cell viability reached to 91.67% (P<0.05) of control , a dose dependent relationship. Bromide and acridine orange staining showed that apoptotic cells were few in the control and naringin group, but in 5mmol/L Hcy treated for 48h group, more and more apoptosis cells have been seen in early stage.But the number of apoptotic cells decreased in the 500μmol/l naringin group. DNA agarose gel electrophoresis no obvious cell apoptosis ladder was observed after 24h but obvious after 48h in 3mmol/L and 5mmol/L Hcy treated cells. This showed that naringin might inhibit Hcy-induced HUVEC apoptosis to a certain extent. The flow cytometry showed that the cell apoptosis rate reached 35.92% in 5mmol/L Hcy treated group after 48h, with a significant statistical difference (P <0.05 ) compared to the control group (1.50%). And the cell apoptotic rate reduced to 2.72% in 5mmol/L Hcy with 500μmol/l naringin treated group after 48h ,with significant difference(P <0.05) compared to 5mmol/L Hcy group. Further confirmed naringin might inhibit the Hcy induced endothelial cell apoptosis.Conclusion Homocysteine has effect to induce HUVEC apoptosis. To some extent, naringin might inhibit the Hcy-induced apoptosis and atherosclerosis.