大车前苷作用于脂多糖诱导的小鼠脓毒症心肌损伤实验研究

Experimental study of plantamajoside in myocardial injury mice with sepsis induced by lipopolysaccharide

目的探讨大车前苷在小鼠脓毒症心肌损伤中的作用。方法选取8~10周龄的雄性C57/BL6小鼠40只,根据处理方式不同将小鼠随机分为4组:生理盐水+生理盐水组、生理盐水+大车前苷组、脂多糖+生理盐水组、脂多糖+大车前苷组,每组10只。脂多糖+生理盐水组与脂多糖+大车前苷组小鼠接受单次腹腔注射脂多糖(10 mg/kg),以构建小鼠脓毒症模型;生理盐水+生理盐水组与生理盐水+大车前苷组小鼠接受同等体积生理盐水腹腔注射。生理盐水+大车前苷组与脂多糖+大车前苷组小鼠给予连续5 d的大车前苷50 mg/(kg·d)灌胃干预,生理盐水+生理盐水组与脂多糖+生理盐水组进行同等体积生理盐水灌胃。实验第1天,先给予小鼠连续5 d大车前苷50 mg/(kg·d)或生理盐水灌胃,第5天给予小鼠单次腹腔注射脂多糖(10 mg/kg)或者等体积生理盐水,饲养12 h后检测心功能并取材。采用实时荧光定量聚合酶链反应检测超氧化物歧化酶2(SOD-2)、谷胱甘肽过氧化物酶-1(GPX-1)和过氧化氢酶(CAT)和相关炎症因子[白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、单核细胞趋化蛋白-1(MCP-1)和白细胞介素-4(IL-4)]的mRNA水平。用检测试剂盒检测丙二醛(MDA)、4-羟基壬烯醛(4-HNE)、GPX-1、TNF-α和MCP-1以及Caspase-3的水平;检测血液中心肌肌钙蛋白I(cTnI)、乳酸脱氢酶(LDH)水平;用TUNEL染色检测心肌细胞凋亡水平。结果与生理盐水+生理盐水组小鼠相比,脂多糖+生理盐水组小鼠的心率、左室射血分数以及左室短轴缩短率降低,心肌损伤标志物cTnI、LDH水平升高,差异有统计学意义(P<0.05);大车前苷可恢复小鼠的心率、左室射血分数、左室短轴缩短率,以及降低心肌损伤标志物cTnI和LDH的水平,提高小鼠生存率(P<0.05)。与脂多糖+生理盐水组小鼠相比,脂多糖+大车前苷组小鼠心脏中MDA、4-HNE的水平降低,差异有统计学意义(P<0.05)。大车前苷可降低小鼠心脏中炎症因子表达、Caspase-3的活性、细胞凋亡水平(P<0.05)。结论大车前苷可以减轻脂多糖诱导的小鼠心肌细胞损伤,改善其心功能。

Objective To investigate the role of plantamajoside in sepsis-related cardiac injury in mice.Methods Forty male C57/BL6 mice aged 8 to 10 weeks were selected and randomly divided into 4 groups according to different treatment methods:normal saline+normal saline group,normal saline+plantamajoside group,lipopolysaccharide+normal saline group,lipopolysaccharide+plantamajoside group,with 10 mice in each group.Mice in lipopolysaccharide+normal saline group and lipopolysaccharide+plantamajoside group received single intraperitoneal injection of lipopolysaccharide(10 mg/kg)to construct a mouse sepsis model;mice in the normal saline+normal saline group and the normal saline+plantamajoside group received intraperitoneal injection of the same volume of normal saline.The mice in the normal saline+plantamajoside group and the lipopolysaccharide+plantamajoside group were given 50 mg/(kg·d)plantamajoside by gavage intervention for consecutive 5 days,and the mice in the normal saline+normal saline group and the lipopolysaccharide+normal saline group were given gavage with the same volume of normal saline.On the first day of the experiment,the mice were given 50 mg/(kg·d)or normal saline intragastric administration for 5 consecutive days.On the fifth day,mice were given a single intraperitoneal injection of lipopolysaccharide(10 mg/kg)or equal volume of normal saline.After feeding for 12 h,cardiac function was detected and samples were collected.Superoxide dismutase 2(SOD-2),glutathione peroxidase-1(GPX-1),catalase(CAT)and related inflammatory factors[interleukin-1β(IL-1β),interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1)and interleukin-4(IL-4)]mRNA levels were determined by real-time quantitative fluorescence polymerase chain reaction.The levels of malondialdehyde(MDA),4-hydroxynonenal(4-HNE),GPX-1,TNF-α,MCP-1 and Caspase-3 were determined by the test kit;the serum levels of cardiac troponin I(cTnI)and lactate dehydrogenase(LDH)were detected;the myocardial cell apoptosis was detected by TUNEL staining.Results Compared with normal saline+normal saline group,the heart rate,left ventricular ejection fraction and left ventricular short axis shortening rate of mice in lipopolysaccharide+normal saline group were significantly decreased,and the myocardial injury markers including cTnI and LDH were significantly increased(P<0.05).Plantamajoside could restore the heart rate,left ventricular ejection fraction,left ventricular short axis shortening rate,reduce the levels of myocardial injury markers including cTnI and LDH,and improve the survival rate of mice(P<0.05).Compared with the lipopolysaccharide+normal saline group,the levels of MDA and 4-HNE in the heart of mice in lipopolysaccharide+plantamajoside group were significantly decreased(P<0.05).Plantamajoside could decrease the expression of inflammatory factors,the activity of Caspase-3 and the level of apoptosis in the heart of mice(P<0.05).Conclusion Plantamajoside can alleviate myocardial cell damage induced by lipopolysaccharide and improve cardiac function in mice.