Effects Of Sanguis Draconis Flavones On Expression Of HMGB1/TLR4/NF-κB P65 Signaling Pathway In Rats With Myocardial Ischemia Reperfusion Injury

Objective:To observe the effects of Sanguis Draconis Flavones on myocardial tissue injury and the expression of HMGB1/TLR4/NF-κB p65 signaling pathway in myocardial ischemia reperfusion rats.Methods:Forty male SD rats were random Ly divided into normal group（Control group）,Sham group（Sham group）,ischemia/reperfusion group（I/R group）and I/R+Sanguis Draconis Flavones pretreatment group（I/R+SDF group）,10 rats in each group.The myocardial I/R model was established by ligation of left anterior descending branch of coronary artery in SD rats and occlusion of blood flow for 30min and reperfusion for 2h.Sham group:after thoracotomy,threading was performed under the left anterior descending branch of coronary artery without ligation.Control group,Sham group and I/R group:14 days before modeling,normal saline was given intragastric administration,once a day,and the volume of intragastric administration was 10m L·kg^-1.I/R+SDF group:14 days before modeling,18mg/m L SDF suspension was given intragastric administration once a day,and the volume of intragastric administration was the same as that of the other groups.After reperfusion,the blood and myocardium of abdominal aorta of rats were collected for the detection of related indicators.The concentration of creatine kinase isoenzyme（CK-MB）and lactate dehydrogenase（LDH）in serum were detected by appropriate reagents;hematoxylin-eosin（HE）staining was used to observe the pathological morphology of myocardial tissue;triphenyl tetrazolium Chlorid（TTC）staining was used to observe the size of myocardial infarction.The mRNA expression of HMGB1、TLR4 and NF-κB p65 were detected by quantitative real-time PCR（RT-PCR）.The protein expression of HMGB1、TLR4 and NF-κB p65 were detected by Westernblot.Results:（1）Compared with the Control group,there were no significant differences in serum CK-MB and LDH concentration and myocardial infarction area in Sham group（P>0.05）,and no significant changes in histopathology.Compared with Sham group,the concentration of serum CK-MB and LDH in I/R group were significantly increased（P<0.05）,the pathological morphology of myocardial tissue was significantly changed,and the area of myocardial infarction was significantly increased（P<0.05）.SDF pretreatment significantly reduced the concentration of CK-MB and LDH in serum of I/R rats（P<0.05）,reduced the area of myocardial infarction（P<0.05）,and alleviated histopathological injury of myocardial I/R rats.（2）Compared with the Control group,the mRNA and protein expressions of HMGB1,TLR4 and NF-κB p65 in Sham group had no significant changes（P>0.05）.Compared with Sham group,the mRNA and protein expressions of HMGB1、TLR4 and NF-κB p65 in I/R group were significantly up-regulated（P<0.05）,suggesting that myocardial I/R injury can activate HMGB1/TLR4/NF-κB p65 signaling pathway.Compared with the I/R group,the mRNA and protein expressions of HMGB1、TLR4 and NF-κB p65 in the I/R+SDF group were down-regulated（P<0.05）,suggesting that SDF may play a protective role in myocardial ischemia reperfusion injury by down-regulating the expression of HMGB1/TLR4/NF-κB p65signaling pathway.Conclusion:1.Pretreatment of Sanguis Draconis Flavones can reduce myocardial ischemia reperfusion injury and protect the heart of rats in vivo;2.Myocardial ischemia reperfusion injury can induce activation of HMGB1/TLR4/NF-κB p65 signaling pathway in myocardial tissue,and pretreatment of Sanguis Draconis Flavones may relieve myocardial I/R injury by inhibiting HMGB1/TLR4/NF-κB p65 signaling pathway.