二氢杨梅素对H2O2诱导人脐静脉内皮细胞氧化损伤的影响

目的 ：研究二氢杨梅素（DMY）对过氧化氢（H2O2）诱导的人脐静脉内皮细胞（HUVECs）损伤的影响并探讨其作用机制。方法：用不同浓度DMY（5μg·mL-1，20μg·mL-1，80μg·mL-1）预处理保护HUVECs 12 h，再用0.5 mmol·L-1 H2O2干预12 h，用MTT法检测细胞活力；用Hoechst33258进行细胞核染色；并取上清液检测超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量；用流式细胞仪分别测活性氧（ROS）和细胞内钙离子含量。结果：DMY能明显提高H2O2（0.5 mmol·L-1）损伤后HUVECs存活率（P＜0.05），增加上清液SOD活性，降低MDA含量，减少细胞内ROS表达，下调细胞内钙离子浓度，其中DMY 5μg·mL-1时效果最明显。结论：DMY对H2O2诱导内皮细胞损伤具有保护作用，其机制与清除细胞内ROS，抑制细胞内钙离子介导的细胞凋亡相关，浓度以DMY 5μg·mL-1时效果最明显。

Effect of dihydromyricetin against H2O2 induced injury in human umbilical vein endothelial cell

Objective: To investigate the effects of pretreatment with DMY on H2O2 induced damage in human umbilical vein endothelial cell (HUVECs) and to explore the related mechanism. Methods: Groups were set as below: normal control group, H2O2 group, groups for low, medium and high dosage of dihydromyricetin (DMY) respectively.Different concentrations of DMY (5μg·mL-1, 20μg·mL-1, 80μg·mL-1) precultured HUVECs for 12 hours,then 0.5 mmol·L-1 H2O2 was used to invervene for 12 hours, using MTT to detect cell viability, Hoechst33258 for apoptotic nuclear staining, the supernatant was taken to determine SOD activity and MDA content. Flow cytometry was used to determine intracellular reactive oxygen species (ROS) and calcium levels. Results: DMY could significantly protect H2O2 (0.5 mmol·L-1) after H2O2-induced injury in HUVECs (P<0.05). We found SOD activity in the supernatant of increased while MDA content and intracellular ROS expression including calcium concentration all decreased of which results became obvious when in 5μg·mL-1 solution of DMY. Conclusion: DMY can reduce intracellular ROS expression through intracellular Ca2+ pathway, DMY concentration of 5μg·mL-1 has the most obvious effect.