Honokiol attenuates myocardial injury by inhibiting immuno-inflammatory response in ischaemic heart disease / 免疫学杂志

ABSTRACT

This study was performed to explore the mechanism of myocardial injury attenuation by honokiol via the inhibition of immuno-inflammatory response in ischaemic heart disease(IHD).Twenty of 60 specific-pathogen-free(SPF)male mice were set as sham-operated group,and the remaining mice were subjected to IHD modeling.After model establishment,mice were classified into model group and honokiol group using a random number table method,with 20 mice in each group.Honokiol group was injected intraperitoneally with 0.2 mg/kg of honokiol,and the sham-operated group and model group were given equal volume of 0.9%sodium chloride solution.Cardiac function parameters,including left ventricular end-diastolic pressure(LVEDP),left ventricular systolic pressure(LVSP),maximum rate of left ventricular pressure rise/decline(LV±dp/dtmax),were measured using electrocardiography.Flow cytometry was used to detect the number of Th17/Treg lymphocytes in blood and calculate the Th17/Treg ratio.The levels of IL-1β,IL-6 and TNF-α were detected by enzyme-linked immunosorbent assay.The pathological morphology of myocardium was observed by immunohistochemical staining,the count of myocardial cells was observed under microscope,and the apoptosis rate of myocardial cells was detected by terminal deoxyribonucleotide transferase-mediated dUTP nick end labelling(TUNEL).Compared with sham-operated group,model group and honokiol group demonstrated a reduction in LVSP and LV±dp/dtmax and an increase in LVEDP(P<0.05).Compared with model group,LVSP and LV±dp/dtmax increased and LVEDP decreased in honokiol group(P<0.05).As for Th17/Treg ratio,model group demonstrated the highest level,followed by honokiol group,and sham-operated group showed the lowest level,with statistical difference(all P<0.05).An increase in serum levels of IL-1β,IL-6 and TNF-α were observed in model group and honokiol group when compared to sham-operated group(P<0.05).Levels of IL-1β,IL-6 and TNF-α in serum showed a reduction in honokiol group when compared to model group(P<0.05).The pathological changes including disordered myocardial cell arrangement,severe myocardial necrosis and structural damage,and massive infiltration of inflammatory cells were found in model group and honokiol group,while those changes were alleviated in honokiol group when compared to model group(P<0.05).The cell apoptosis rate showed an increase in model group and honokiol group when compared to sham-operated group(P<0.05),while the cell apoptosis rate was decreased in honokiol group when compared to model group(P<0.05).In conclusion,honokiol pretreatment can improve cardiac function and diminish myocardial injury in IHD.