和厚朴酚通过抑制缺血性心脏病的免疫炎症反应减轻心肌损伤

Honokiol attenuates myocardial injury by inhibiting immuno-inflammatory response in ischaemic heart disease

目的研究和厚朴酚通过抑制缺血性心脏病(IHD)的免疫炎症反应减轻心肌损伤的机制。方法60只SPF级雄性小鼠,取20只作为假手术组,剩余小鼠行IHD造模,造模成功后采用随机数字表法分为模型组、和厚朴酚组,每组20只小鼠。和厚朴酚组腹腔注射0.2 mg/kg和厚朴酚,假手术组、模型组给予等量等容积0.9%氯化钠溶液。采用心电图检测心功能[左心室舒张末期压(LVEDP)、左心室收缩压(LVSP)、左室内压力最大上升与下降速率(LV±dp/dt_(max))];流式细胞仪检测血Th17/Treg淋巴细胞数量,计算Th17/Treg比值;酶联免疫吸附法检测白细胞介素-1β(IL-1β)、IL-6、肿瘤坏死因子-α(TNF-α)水平;免疫组织化学染色法观察心肌组织病理形态,显微镜下观察心肌细胞计数,末端脱氧核糖核酸转移酶介导的d-UTP缺口末端标记(TUNEL)法检测心肌细胞凋亡率。结果与假手术组比较,模型组、和厚朴酚组LVSP、LV±dp/dt_(max)均下降,LVEDP上升(P<0.05);与模型组比较,和厚朴酚组LVSP、LV±dp/dt_(max)增加,LVEDP下降(P<0.05)。与假手术组比较,模型组、和厚朴酚组Th17/Treg上升(P<0.05);与模型组比较,和厚朴酚组Th17/Treg下降(P<0.05)。与假手术组比较,模型组、和厚朴酚组IL-1β、IL-6、TNF-α水平上升(P<0.05);与模型组比较,和厚朴酚组IL-1β、IL-6、TNF-α水平下降(P<0.05)。与假手术组比较,模型组、和厚朴酚组心肌细胞排列较为紊乱,心肌坏死与结构损伤严重,炎症细胞大量浸润;与模型组比较,和厚朴酚组心肌损伤得到缓解。与假手术组比较,模型组、和厚朴酚组心肌细胞凋亡率均上升(P<0.05);与模型组比较,和厚朴酚组心肌细胞凋亡率下降(P<0.05)。结论和厚朴酚可通过抑制免疫炎症反应以提高IHD小鼠心功能并减轻心肌损伤。

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/dt_(max)),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/dt_(max) and an increase in LVEDP(P<0.05).Compared with model group,LVSP and LV±dp/dt_(max) 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.