Study On The Protective Effect And Mechanism Of RLMTF On Huvec Following Oxidative Injury

Objectives: To study the protective effects and mechanisms of Rosa laevigataMichx total flavonoids (RLMTF) on human umbilical vascular endothelial cells(HUVEC) following oxidative damage.Methods:1. To construct the oxidative injury model, H2O2with differentconcentrations were used to treat HUVEC. The morphological changes in HUVEC ofeach groups were observed by the microscope, and the morphological changes inHUVEC of each group were observed employing inverted fluorescent microscopeafter Hoechst33258staining. The cell vitality was measured by MTT.2. Effect of theRLMTF on clearance of superoxide anion radical was assayed performing the methodof pyrogallol autoxidation, its hydroxyl free radical clearing capacity was determinedusing Fenton reaction with rutin and Vc as control.3. The cultured HUVEC wererandom divided into six groups:①control group,②H2O2oxidative damage group,③Vc pretreated group,④-⑥various dosages of RLMTF (0.12mg/mL,0.24mg/mLand0.48mg/mL respectively) pretreated groups. The SOD, CAT, GSH-Px activitieswere assayed in cell culture medium of each group. Western blotting was used todetect the expression of the anti-apoptosis protein Bcl-2and the pro-apoptosis proteinBax.Results:1. Contrast to the control, the cell vitality of600,800and1000μmol/LH2O2groups were decreased significantly (P＜0.01), but the200μmol/L and400μmol/L H2O2groups without significant diviation (P＞0.05).2. With the concentration increaseing from20to200μg, the scavenging capacities ofhydroxyl radical of RLMTF and Vc were increased gradually, while their clearanceactivities of superoxide anion showed the tendency of increasing firstly and reductionafterwards. The scavenging effect of hydroxyl radical of rutin existed the tend-ency of increasing firstly and reduction afterwards, while the clearance effect of su-peroxide anion was decreased gradually.3.①The cell vitalities in different RLMTF concentration groups were obviously raised than those of H2O2groups (P＜0.01).②Compared with H2O2oxidative injury group, the activities of SOD in0.24mg/mLand0.48mg/mL RLMTF groups were apparently increased (P＜0.01), while therewas no significant difference in0.12mg/mL RLMTF group. The activities of CAT inall RLMTF groups were significantlty higher than those of H2O2oxidative injurygroup (P＜0.05or P＜0.01). The activities of GSH-Px in all the RLMTF groups weremore significantly enhanced than those in H2O2oxidative injury group (P＜0.01).③The expression levels of Bcl-2in0.24mg/mL RLMTF group and0.48mg/mLRLMTF group except0.12mg/mL RLMTF group were significantlty higher thanthose of H2O2oxidative injury groups (P＜0.05), and the expression levels of Bax inall RLMTF groups were significantlty lower than those of H2O2oxidative injurygroups (P＜0.05or P＜0.01).Conclusions: RLMTF can protect HUVEC from oxidative injury induced by H2O2.The mechanisms were concerned with its fightting against free radicals, increasing theactivities of SOD, CAT, GSH-Px, up-regulating the expression of Bcl-2anddown-regulating the level of Bax.