Quercetin Inhibits Excised Saphenous Vein Oxidative Damage And Inflammation Reaction

Objective:To explore the function of quercetin which protects the excised great saphenous vein from oxidative damage and inflammatory reaction induced by mechanical damage,then find out the cytokines which take part in the protecting progress.It provides the theoretical foundation for that quercetin being used to protect the excised great saphenous vein during CABG.Methods:The great saphenous veins were collected from 15 patients undergoing coronary artery by pass grafting?CABG?and cultured,which were divided into 2 groups for oxidative damage experiments?9 cases?and mechanical damage experiments?6cases?.The great saphenous vein from the same patient was divided into 3 parts,as 3groups,cut them with scissors for about 2-3 mm long ring vascular tissue.1.Collected the great saphenous veins from 3 patients which were residual during the CABG.Control group,H₂O₂ group were cultured in DMEM,H₂O₂+quercetin group was cultured in DMEM which contains 200umol/L quercetin,after 1h,treated the veins of H₂O₂ group and H₂O₂+quercetin group by100 umol/L H₂O₂.4h later,Recovered the culture supernatants,then detected the NO content by the nitric oxide?NO?kits.2.Collected the great saphenous veins from 6 patients which were residual during the CABG.Treated as 1,after 24h,treated by 100 umol/L H₂O₂.4h later,recovered the culture supernatants and vascular tissue,then detected the NO,SOD,MDA content by the relevant kits.3.Collected the great saphenous veins and cut them with scissors for about 2-3mm long ring vascular tissue and were cultured in DMEM.Shear the veins of wound group and wound+quercetin group using scissors to form a 2mm incised wound.Do nothing to control group.wound group were cultured in DMEM,and wound+quercetin group were cultured in 200 umol/L quercetin DMEM.24h later,collected the veins,detected the mRMA level of IL-6,TNF-?,CCL20,PCNA,VEGF by qRT-PCR.Then collected the veins for HE staining and PCNA and VEGF immunofluorescent staining.Results:1.In the oxidation experiments,hydrogen peroxide can cause oxidative damage,leading to NO generation increased?P<0.05?.There was no difference of statistics in NO production between the group pretreated by quercetin 1h and the H₂O₂ group?P<0.05?.2.After treated 24 h by quercetin,the production of NO,MDA in H₂O₂+ quercetin group were obvious lower than that of H₂O₂ group,and SOD was higher.?P<0.01?.3.In the mechanical damage experiment,the mRNA expressions of IL-6,TNF-?,PCNA were decreased compared with the wound group?P<0.05?,and CCL20 and VEGF showed no differences?P>0.05?.4.The HE results revealed that the vein intimal thickness in wound group were higher than the wound+quercetin group.In wound+quercetin group,the expression of PCNA decreased,VEGF didn't change compared with the wound group from the IF staining.Conclution1.Quercetin can inhibit the oxidative damage induced by hydrogen peroxidethe,and protect the veins by reducing the expressions of NO,MDA,and promoting the expression of SOD.2.Quercetin can protect the great saphenous vein by decreasing the expression of inflammatory cytokines such as TNF-?,IL-6,and suppressed the vein endothelial thickness by inhibiting cell proliferation.