Role Of Caspase 3 In Luteolin Protects Isolated Rat Heart Against Anoxia/reoxygenation Injury

Objective: The effect of luteolin on myocardiac hypoxia/reoxygenation(A/R)injury was investigated by establishing a rat heart ischemia-reperfusion injury model,and its mechanism of action was preliminary studied.Methods: 40 of 6-8 weeks healthy adult male SD rats were divided into five groups at random: Control group,Anoxia/reoxygenation(A/R)group,A/R+LU group,Luteolin low-dose intervention group,Luteolin high-dose intervention group,Luteolin and inhibitors intervention group.A Langendorff perfusion device was used to establish a rat heart A/R injury model,and luteolin was used for high and low doses and LY294002 intervention.Power Lab was used to collect the data of systolic blood pressure,heart rate and maximum rate of rise/fall of left ventricular pressure(dp/dtmax)isolated rat hearts.Triphenyltetrazolium chloride(TTC)was used to investigate infarct size of isolated rat hearts.Collection of perfusion fluid for detection of the concentration of lactate dehydrogenase(LDH)adn creatine kinase(CK).Western blotting was used to investigate the expression level of Bcl-2,caspase-3 and cytochrome c.Terminal dexynucleotidyl transferase(TdT)-mediated dUTP nick end labeling(TUNEL)was used to observe the level of apoptosis of myocardium.Results:1.Luteolin high and low doses can significantly inhibit the LDH activity in perfusate(p<0.05),in which the high dose group is more significant;luteolin high dose intervention can significantly inhibit the CK activity in perfusate(p<0.05);2.Compared with the A/R group,the heart rate,LVDP,and +dp/dt max were significantly increased(p<0.05)and-dp/dt max was significantly lower in the luteolin-treated rats hearts during reoxygenation(p<0.05);3.luteolin intervention can significantly reduce the A/R injury-induced myocardial infarct size(p <0.05 VS A / R group);4.Luteolin could significantly up-regulate the expression of PI3 K and p-Akt in heart tissue after A/R treatment(p<0.05 VS A/R group);5.Luteolin could significantly up-regulate the expression of caspase-3 protein in heart tissue after a/r up-regulation(p<0.05 VS A/R group),and significantly down-regulate cleaved caspase-3 protein expression(p<0.05 VS A/R group).In addition,luteolin intervention also significantly inhibited the caspase-3 protein activity(p<0.05 VS A/R group);6.PI3 K selective inhibitor LY294002 can significantly reduce the positive effect of luteolin(p<0.05).Conclusion: Luteolin has a protective effect on A/R injury in isolated rat heart,and the mechanism of inhibiting cardiomyocyte apoptosis includes PI3K/Akt/caspase 3 signaling pathway.