The Protective Effect Of Ellagic Acid On Lipotoxic Myocardial Injury And Its Correlation With AMPK Pathway

Objective:In this study,palmitic acid(PA)was used to stimulate H9c2cardiomyocytes to establish a model of lipotoxic myocardialinjury.After intervention with ellagic acid(EA),the protective effect of EA on lipotoxic myocardial injury and its relationship with AMPK/m TORC1/p70S6K signaling pathway were investigated,to provide a theoretical basis for EA in the treatment of lipotoxic myocardial injury.Methods:1.H9c2 establishment of a model of myocardial lipotoxic injury:differentconcentrations of PA(0,0.1,0.2,0.4,0.8 mmol·L^-1)were given to stimulate H9c2cardiomyocytes for24 h;respectively at different time points(0,12,24,48 h),give PA 0.2 mmol·L^-1stimulate cardiomyocytes,assessment of cell viability using MTT methods,to screen out the effective concentration and time,determine the appropriate conditions for establishinga H9c2 cardiomyocytelipotoxicitymodel.DCFH-DA probe,MDA kit and SOD kit,were used to detect oxidative stress level,detectionof apoptosis by TUNEL staining,the expression of AMPK/m TORC1/p70S6K pathway related protein and apoptosis pathway related protein was detected by western blot method.2.Objective to investigate the protective effect of EA on high-fat injured cardiomyocytes:PA 0.2 mmol·L^-1was selected to stimulate cardiomyocytes for 24 h.After EA pretreatment,cell viability was evaluated by MTT assay,oxidative stress level was detected by DCFH-DA probe,MDA kit and SOD kit,apoptosis was detected by TUNEL staining,and AMPK/m TORC1/p70S6K pathway related proteins and apoptosis pathway related proteins were detected by Western blot.Results:Part 1Study on the lipotoxic effect of PA on H9c2 cardiomyocytesWith the increase of PA concentration and stimulation time,the cell viability gradually decreased,showing a concentration and time-dependent trend.Compared with Control group,when PA 0.2 mmol·L^-1stimulated cardiomyocytes for 24 h,the activity of cardiomyocytes began to decrease significantly(P<0.05).Compared with the Control group,the level of oxidative stress and the rate of apoptosis were significantly increased in PA 0.2mmol·L^-1group.Compared with Control group,the expression of p-AMPK was significantly decreased in the 0.2 mmol·L^-1PA group,and the expression of p-m TORC1 and p-p70S6K was significantly increased,the expression of Bax and Cleaved caspase-3 increased significantly,while the expression of Bcl-2 decreased significantly(P<0.05).Part 2Protective effect of EA on myocardial cells injured by HyperlipidemiaWhen PA 0.2mmol·L^-1wasgiven to cardiomyocytes,the viability of cardiomyocytes was significantly inhibited.However,after pretreated with different concentrations of EA,the cell viability gradually increased in a concentration dependent manner.Compared with PA 0.2 mmol·L^-1group,after pretreatment with EA20?mol·L^-1,the viability of cardiomyocytes was significantly increased,the level ofoxidative stress was significantly decreased,the apoptosis rate was significantly decreased,the expression of p-AMPK protein was significantly increased,and the expression of p-m TORC1 and p-p70S6K was significantly decreased(P<0.05),but the total protein expression was not significantly changed;The expressions of Bax and Cleaved caspase-3 were significantly decreased,while the expression of Bcl-2was significantly increased(P<0.05).Conclusion:EA has a protective effect on high-fat injured cardiomyocytes,and its specific mechanism may be related to the activation of AMPK/m TORC1/p70S6K signaling pathway,so as to improve cardiac function.