To Investigate The Mechanism Of Ginsenoside Rg1 In Improving Myocardial Infarction By Regulating Ferroptosis-Related Factor HMGB1

Background and Objective:Myocardial Infarction(MI)is the necrosis of myocardial cells caused by vascular ischemia and hypoxia,which has been considered as a serious public health problem worldwide.Previous studies have pointed to a potential link between MI and inflammatory responses.High Mobility Group Box 1(HMGB1),as one of the important regulators of inflammatory response,has been found to be regulated by ferroptosis.In addition,existing studies have shown that MI is closely related to ferroptosis.Factors extracted from traditional Chinese medicine are classic topics in the field of cardiovascular disease treatment.Among them,a wide range of studies have shown that Ginsenoside Rg1(Rg1)plays an important regulatory role in the process of MI and the inflammatory response after MI.However,the underlying mechanisms by which Rg1 alleviates MI and post-MI inflammatory responses are poorly understood.In this paper,the specific mechanism of Rg1 in MI is analyzed,which provides a solid evidence base for the clinical application of TCM extracted factors in cardiovascular diseases.Methods: This study was based on two types of models,animal model and cell model.First,C57BL/6 mice were randomly divided into Sham operation group(Sham group),MI group(MI group),Rg1 plus drug group(Rg1 group)and Rg1 treated MI group(Rg1+MI group).The MI mouse model was established by Left Anterior Descending coronary artery(LAD)ligation.After 3 weeks,echocardiography and TTC staining were used to detect myocardial infarction-related indicators.Secondly,primary cardiomyocytes isolated from neonatal rats were cultured in Anoxia/Reoxygenation(A/R)cell model.The optimal concentration of Rg1 was detected by CCK-8 test and divided into Con group,Rg1 group,A/R group,and Rg1+A/R treatment group.After the cell model was successfully established,the m RNA levels of inflammatory factors IL-6 and TNF-α were detected by real-time fluorescence quantitative PCR.For ferroptosis detection,the morphological changes of mitochondria in mouse cardiac tissues were observed by transmission electron microscopy(TEM).Western Blot analysis was used to detect the expression of GPX4,FSP1,CoQ10 and HMGB1 in the two models,and the ferrous ion level was measured by related kits.To enhance correlation validation,GSH was measured with the kit in the cell model,and ROS production was also assessed by DCFH-DA staining.Finally,the intervention of HMGB1 inhibitor Glycyrrhizic acid(GL)was used to study the specific molecular mechanism.On the basis of the original four cell models,GL group and GL+A/R group were added.Western Blot and real-time fluorescence quantitative PCR were used to detect the expression of HMGB1 and the ferroptosis-related molecules such as GPX4,FSP1,and CoQ10.Results:In the animal model,compared with the Sham group,the ejection fraction and fractional shortening of the MI group were significantly decreased,and the left ventricular end-diastolic and end-systolic diameters were increased,accompanied by increased m RNA levels of inflammatory factors such as IL-6 and TNF-α.In ferroptosis-related tests,there was more mitochondrial morphology destruction,and the levels of GPX4,FSP1,and CoQ10 were decreased,while the levels of ferrous ion and HMGB1 were increased.However,compared with MI group,Rg1+MI group reversed the above ferroptosis indicators,reduced myocardial infarct size,improved cardiac function,slightly improved mitochondrial morphology,and significantly decreased the expression of inflammatory factors.In the cell model,compared with the Con group,the m RNA levels of inflammation-related factors IL-6 and TNF-α and the expression of ferroptosis-related pro-inflammatory factor HMGB1 were increased in the A/R group,and the levels of GPX4,FSP1 and CoQ10 were decreased in the A/R group.The levels of GSH and Fe2+ were increased,and ROS accumulation was increased.Compared with the A/R group,the expression of inflammatory factors IL-6,TNF-α and HMGB1 in the Rg1+A/R group was also observed to be decreased,and the related ferroptosis index was also reversed.In the cell model,when GL group and GL+A/R group were added,the level of HMGB1 in GL group did not change significantly compared with Con group and Rg1 group,and the ferroptosis indicators such as GPX4,FSP1,CoQ10 also did not change significantly compared with Con group and Rg1 group.In addition,compared with other groups,the level of HMGB1 in GL+A/R group did not recover to the level of Con group,but the expression of HMGB1 in GL+A/R group was lower than that in A/R group,which was similar to that in Rg1+A/R group.The levels of GPX4,FSP1 and CoQ10 in GL+A/R group were similar to those in Rg1+A/R group,and the degree of ferroptosis was reduced compared with A/R group.Conclusions: Rg1 ameliorated myocardial injury and improved cardiac function in MI mice by inhibiting inflammatory response,which may be related to the ferroptosis level regulated by HMGB1.