大黄酸对正常和氧化损伤内皮细胞的增殖和氧化保护作用

目的：观察大黄酸对正常和氧化损伤的人脐静脉血管内皮细胞(HUVEC)的影响。方法：建立H2O2氧化损伤模型，采用不同浓度的大黄酸对内皮细胞进行处理，检测内皮细胞乳酸脱氢酶(LDH)释放率、丙二醛(MDA)含量、一氧化氮(NO)含量、一氧化氮合酶(NOS)活力和超氧化物歧化酶(SOD) 活力及谷胱甘肽过氧化物酶(GSH-Px) 活力的变化；采用流式细胞术研究内皮细胞的凋亡情况，探讨大黄酸对内皮细胞的保护作用。结果：大黄酸浓度在16μmol/L以下时，对HUVEC的增殖无显著性影响；浓度在2μmol/L以上时，减轻HUVEC受到氧化损伤的程度，对氧化性损伤具有保护作用；同时降低了LDH释放率，下调了MDA含量，提高了NO含量和NOS、SOD、GSH-Px的酶活力，显著减少了细胞凋亡率。结论：HUVEC经2～16μmol/L大黄酸处理，可以有效减轻H2O2对其造成的氧化损伤，维持正常的生理形态。

Proliferative and Protective Effects of Rhein on Normal and Oxidatively Injured Endothelial Cells

Objective: To study the effect of rhein on the proliferation and oxidative damage of human umbilical vein endothelial cells (HUVEC). Methods: An oxidative injury model was established with H2O2. HUVECs were incubated with rhein at various concentrations and the availability of rhein for protecting endothelial cells was explored. The release rate of lactic acid dehydrogenase (LDH), the contents of malondialdehyde (MDA) and NO, and the activities of nitrogen oxide synthase (NOS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined. Flow cytometry was employed to investigate the apoptosis of HUVECs. Results: Rhein had no obvious effect on the proliferation of HUVECs when the concentration of rhein was less than 16 μmol/L. However, rhein at a concentration of more than 2 μmol/L could reveal significant protection against oxidative damage in HUVECs. The release rate of LDH and the content of MDA revealed an obvious decrease, whereas the content of NO and the activities of NOS, SOD and GSH-Px exhibited an obvious increase. The rates of apoptosis and necrosis were reduced significantly. Conclusion: Rhein can maintain the normal physiology of the cells and prevent the cells from H2O2-induced injury at a concentration of 2-16 μmol/L. It is particularly important for the prevention and treatment of atherosclerosis.