Effects of quercetin on proliferation of human endothelial progenitor cells

Objective To investigate the possible mechanism of the injury induced by oxygen free radical to endothelial progenitor cells(EPCs),and the protective effects of quercetin(Que) on EPCs.Methods Separated EPCs from the human umbilical cord blood,and induced the cells to differentiate.The cells then were randomly assigned into 3 groups:the control group、H2O2 group(H2O2 500μmol/L to model oxidative stress injury on EPCs)、Que group(Que 60μmol/L,90μmol/L,120μmol/L+H2O2 500μmol/L to culture).WST-1 assay was used to observe the proliferation of EPCs in 24 and 48 hours' time in the culture process.Results Que at 60～90μmol/L could stimulate EPCs proliferation,while Que at 120μmol/L represented quite the opposite compared with the control group(P0.05).The inhibition on EPCs was more obvious in 24 hours's time compared with the 24 hours'(P0.05).The proliferation ability of EPCs was dramatically reduced in H2O2 group compared with the control group,which had apparent statistical significance(P0.01).Pretreating with Que at 60～120μmol/L,the proliferation ability of EPCs induced by H2O2 had been improved dramatically,and it was time-dependent and dose-dependent in the experiment range,which had obvious statistical significance compared with H2O2 group(P0.01).Conclusion Oxidative stress impairs the proliferation ability of EPCs,while Que can improve it dramatically.