Improvement effects of myricetin against myocardial ischemia/reperfusion injury in rats

WANG Bo; LI De-fang; HAN Ji-chun; ZHENG Qiu-sheng

Abstract：Objective:To evaluate the cardioprotective effects of myricetin (YMS) on ischemia/repertusion (I/R) injury using an isolated Langendorff rat heart model and study the possible mechanism of YMS against I/R injury.Methods:Using the Langendorff modeling method,the experiment was divided into normal group,model group,YMS group and YMS + GW9662 (PPARγ selective blocker) group.The left ventricular developed pressure (LVDP),coronary flow (CF) and the maximum up/down rate of the left ventricular pressure (dp/dtmax) were documented as the indices of myocardial function by a physiological recorder.Myocardial infarct size was macroscopically estimated using 2,3,5-triphenyltetrazolium chloride (TTC) staining.The levels of inteleukin-6 (IL-6),C-reactive protein (CRP) and tumor necrosis factor-α (TNF-αt) were measured by ELISA.The proteins levels of peroxisome proliferators-activated receptor gamma (PPARγ) and nuclear factor-k-gene binding (NF-κB)were measured by Western blot.Results:Pretreatment with YMS improved the maximum up/down rate of the left ventricular pressure (dp/dtmax),raised the LVDP,improved CF,reduced the amount of CRP,IL-6 and TNF-α,upregulated PPARγ expression,and downregulated NF-κB expression.However,the effects of YMS were reversible by co-treatment with PPAR-γ inhibitors (GW9662).Conclusion:I/R injury in rat hearts can be prevented by pretreating with YMS which modulates PPARγ activation-dependent NF-κB signaling pathways.