黄芩素通过抑制氧化应激与凋亡改善小鼠心肌重构的作用研究

Effects of Baicalein on Myocardial Remodeling in Mice by Inhibiting Oxidative stress and Apoptosis

目的 研究黄芩素(Bai)对异丙肾上腺素(ISO)导致小鼠心肌重构的保护作用,初步探讨Bai改善心肌损伤的作用机制。方法 雄性SPF级小鼠40只,随机分为对照组(Con组)、阳性对照组(Con+Bai组)、模型组(ISO组)、模型给药Bai组(ISO+Bai组),每组各10只。ISO造模结束后,Con+Bai组和ISO+Bai组腹腔注射Bai, Con组和ISO组腹腔注射等体积二甲亚砜(DMSO)。测定心脏质量比,苏木精-伊红/马松(HE/Masson)染色检测心肌损伤和心肌纤维化,心脏超声心动图测定左心室厚度及收缩功能。检测小鼠血清中心肌肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)、谷胱甘肽过氧化物酶(GSH-Px)活性和血清中丙二醛(MDA)的含量水平。Western blot检测炎症因子、凋亡蛋白、信号通路等相关蛋白的表达水平。结果 HE/Masson染色结果显示,Bai可抑制ISO诱导的心肌损伤和心肌纤维化;ISO组心脏质量、体积、LVPWd、IVSd明显增加、CK-MB、LDH、MDA、I型胶原纤维(Collagen I)、Smad2转录因子、半胱氨酸蛋白酶-3(caspase-3)、半胱氨酸蛋白酶-9(caspase-9)、Bcl-2关联X蛋白(Bax)、核因子-κB(NF-κB)、白介素-6(IL-6)、肿瘤坏死因子(TNF-α)蛋白表达水平高于Con组(P<0.05),B淋巴细胞瘤-2基因(Bcl-2)、超氧化物歧化酶(SOD1)、过氧化氢酶(CAT)、磷酸化蛋白激酶B(P-AKT1)、磷脂酰肌醇-3-激酶(PI3K)蛋白表达、GSH-Px活性低于Con组(P<0.05);ISO+Bai组心脏质量、体积、LVPWd、IVSd、CK-MB、LDH、MDA、BNP、alpha、p-Smad2、Collagen I、caspase-3、caspase-9、Bax蛋白表达、NF-κB(p65)、TNF-α、IL-6含量低于ISO组(P<0.05),Bcl-2、SOD1、CAT、P-AKT1、PI3K蛋白表达、GSH-Px活性高于ISO组(P<0.05)。结论 Bai对ISO导致的小鼠心肌重构具有抑制其氧化应激和减少细胞凋亡的作用,作用机制可能与激活PI3K/AKT1信号通路抗氧化应激有关,为Bai预防和治疗心肌重构提供新的思路和理论基础。

Objective To study the protective effect of Baicalein(Bai) on myocardial remodeling induced by isoproterenol(ISO) in mice, and to explore the mechanism of Bai improving myocardial injury.Methods Male SPF grade mice were randomly divided into control group(Con),positive control group(Con+Bai),model group(ISO) and model administration baicalein group(ISO+Bai),with 10 mice in each group.After ISO modeling, the Con+Bai group and ISO+Bai group were intraperitoneally injected with Baicalein, and Con group and ISO group were intraperitoneally injected with equal volume of dimethyl sulfoxide(DMSO).The Cardiac weight ratio was measured, myocardial injury and myocardial fibrosis were detected by HE/Masson staining, and left ventricular thickness and systolic function were measured by echocardiography.The activities of creatine kinase isozyme(CK-MB),lactate dehydrogenase(LDH),glutathione peroxidase(GSH-PX) and the content of malondialdehyde(MDA) in serum were measured.The expression levels of inflammatory factors, apoptotic proteins, signal pathways and other related proteins were detected by Western blot.Results The results showed that HE/Masson staining showed that Bai could inhibit myocardial injury and myocardial fibrosis induced by ISO.Heart mass, volume, LVPWd, and IVSd were significantly increased in the ISO group.CK-MB,LDH,MDA,collagen type I fibrils(Collagen I),Smad2 transcription factor, cysteine protease-3(caspase-3),cysteine protease-9(caspase-9),Bcl-2-associated X protein(Bax),nuclear factor-κB(NF-κB),interleukin-6(IL-6),tumor necrosis factor(TNF-α) protein expression levels were higher than those in the Con group(P<0.05).B lymphocytoma-2 gene(Bcl-2),superoxide dismutase(SOD1),catalase(CAT),phosphorylated protein kinase B(P-AKT1),phosphatidylinositol-3-kinase(PI3 K) protein expression, and GSH-Px activity were lower than those in the Con group(P<0.05).Heart mass, volume, LVPWd, IVSd, CK-MB,LDH,MDA,p-Smad2,Collagen I,caspase-3,caspase-9,Bax protein expression, NF-κB(p65),TNF-α,IL-6 content were significantly lower in the ISO+Bai group than those in the ISO group(P<0.05).Bcl-2,SOD1,CAT,P-AKT1,PI3 K protein expression, and GSH-Px activity were higher than those in the ISO group(P<0.05).Conclusion Bai can inhibit oxidative stress and reduce apoptosis in myocardial remodeling induced by ISO in mice.The mechanism of action may be related to the activation of PI3 K/AKT1 signaling pathway to resist oxidative stress, which provides new ideas and theoretical basis for the prevention and treatment of myocardial remodeling by Baicalein.