The Protective Effect Of Astragalus Polysaccharide On Umbilical Vein Endothelial Cells Injured By Hypoxia And Reoxygenation

Objective:Ischemic heart disease is one of the most common diseases with the highest morbidity and mortality?Timely restoration of blood flow to the ischemic myocardium(reperfusion)became the standard treatment for these patients?Reperfusion was rapidly demonstrated to limit infarct size,improve long-term myocardial function,change the healing pattern of the infarcted zone,and more importantly,reduce mortality?Many experimental and clinical evidence demonstrate that reperfusion induces additional damage to the myocardium,known as reperfusion injury,Which clinical symptoms include myocardial stunning,arrhythmia,and the phenomenon of "no-reflow" in the myocardial microvascular?The occurrence of"no-reflow" in cardiac microvessels is closely related to endothelial dysfunction?Therefore,it is of great significance to protect endothelial cells against myocardial ischemia-reperfusion injury?According to traditional Chinese medicine theory,the occurrence of "no-reflow" phenomenon of myocardial ischemia-reperfusion injury is closely related to qi deficiency and blood stasis?The deficiency of heart Qi is also an important cause of blood stasis,and benifiting qi for activating blood circulation method is the main method for treating MIRI in traditional Chinese medicine?Astragalus is a traditional Chinese herbal medicine for invigorating qi.?Astragalus polysaccharides are one of the main components of Astragalus membranaceus,Studies have shown that astragalus polysaccharides can protect endothelial cell by antioxidant.anti-inflammatory?maintain the normal mitochondrial structure?In this experiment,umbilical vein endothelial cells were used as target cells to investigate the effects of astragalus polysaccharides on endothelial cell oxidative stress and mitochondria induced by Hypoxia/Reoxygenation injury?Endothelial dysfunction plays an important role in the initiation and development stages of myocardial ischemia To probe into the effect of astragalus polysaccharides(APS)on the content of ROS?MDA,the structure of mitochondria,the expression of Drpl,the ratio of LDH leaked from the human umbilical vein endothelial cells exposed to hypoxia-reoxygenation injury?Methods:Human umbilical vein endothelial cells cultured to 5 generation were divided into normal control group,model group,model+ APS 25?g.ml-1 group,positive drug group?The model and the drug-treated groups were replaced with modified ischemia-mimetic solution after the cell adherence and cultured 4h in a hypoxia incubator(5%CO2,94%N2,1%O2),Then replaced with complete medium and placed in a normal incubator(5%C02,95%O2)for 16hS?the model and each drug-treated group were added with corresponding concentrations of drugs when the cells exposed to hypoxia and reoxygenation,the control group is always cultured under normal conditions for 24 hS?MTT assay was used to evaluate the cell viabilities?To observe the effect of APS on content of reactive oxygen species(ROS),malondialdehyde(MDA),the ratio of lactate dehydrogenase(LDH)leaked from cells,and mitochondrial membrane potential(JC-1),mitochondria structure,,the expression of Drpl in HUVEC exposed to hypoxia/reperfusion?Results:Compared with the normal control group,the contents of ROS,MDA,the expression of Drpl and the ratio of LDH leaked from cells in the model group was significantly higher than those in the normal control group(P<0.05),and the mitochondrial membrane potential was lower than that in the normal control group(P<0.05)),Indicating that ischemia-reperfusion induced the occurrence of oxidative stress by free radicals?increased production of lipid peroxidation products and mitochondria fission?The contents of ROS,MDA,the expression of Drpl and ratio of LDH leaked from cells in model+APS 25 ?g ml-1APS group and positive-drug group were significantly lower than those in model group(P<0.05),and the mitochondrial membrane potential was higher than that in model group(P<0.05),indicating that astragalus polysaccharides can reduce ROS,MDA,LDH production and increase mitochondrial membrane potential?inhibit the mitochondria fission in Huvec exposed to hypoxia/reoxygenation injury?Conclusion:Astragalus polysaccharides can protect hypoxia/reoxygenation injury of human umbilical vein endothelial cells?The mechanism may be related to the inhibition of APS on the production of free radicals and lipid peroxidation products?maintain the normal mitochondria structure in vascular endothelial cells and the reduction of oxidative stress?...