越桔原花青素对大鼠心肌纤维化作用的影响

目的探讨越桔原花青素(procyanidin from Vaccini-um,PC)对大鼠心肌纤维化作用的影响及其机制。方法体内实验以异丙肾上腺素(isoprenaline,Iso)5 mg.kg-1.d-1背部皮下注射,构建大鼠心肌纤维化模型,同时以灌胃方式给予PC 100、200、400 mg.kg-1.d-1,分光光度法检测左心室心肌组织中羟脯氨酸(hydroxyproline,Hyp)、丙二醛(ma-londialdehyde,MDA)含量和超氧化物歧化酶(superoxide dis-mutase,SOD)活性;电镜观察心肌超微结构变化。体外实验采用细胞培养技术以血管紧张素Ⅱ(angiotensinⅡ,AngⅡ)建立新生大鼠心肌成纤维细胞(cardiac fibroblast,CFb)增殖模型,给予25、50和100 mmol.L-1的PC干预。采用四唑盐(MTT)比色法测定细胞增殖;ELISA法测定Ⅰ、Ⅲ胶原及转化生长因子β1(TGF-β1)蛋白的含量。结果PC可剂量依赖性地降低心肌组织中Hyp、MDA含量、增强SOD活性,同Iso组比较差异有统计学意义(P<0.05或P<0.01),电镜结果显示:PC可缓解Iso所导致的心肌损伤。体外实验部分PC(25、50和100 mg.L-1)可抑制AngⅡ诱导的CFb增殖、胶原合成增加及TGF-β1蛋白含量增多,与AngⅡ组比较差异具有统计学意义(P<0.05或P<0.01)。结论PC可通过抗氧化作用,抑制CFb的增殖及胶原的合成,进而抑制大鼠心肌纤维化,对心肌具有一定的保护作用。

Effects of procyanidin from vaccinium on the myocardial fibrosis in rats

Aim To explore the effect of Procyanidin from Vaccinium(PC) on the myocardial fibrosis and its mechanism.Methods The model of myocardial fibrosis in rats was built by subcutaneous injection of isoprenaline(Iso) for 5 mg·kg-1·d-1 in vivo.Meanwhile,rats were treated with PC 100,200 and 400 mg·kg-1·d-1 by gastrointestinal administration.The contents of hydroxyproline(Hyp),malondialdehyde(MDA) and the activity of superoxide dismutase(SOD) in left ventricle were assayed with spectrophotometry respectively.Changes of myocardial ultrastructure were observed by electronic microscope.The cultured neonatal rat CFb was isolated by trypsin digestion method.The proliferation of CFb was induced by Angiotensin Ⅱ and assessed by thiazolyl blue(MTT) assay.PC was added in different dosage(25,50 and 100 mmol·L-1).Ⅰ,Ⅲ collagen quantification and TGF-β1 levels were determined by the ELISA.Results In vivo,compared with model group,the contents of hydroxyproline and malondialdehyde of left ventricle were significantly reduced and the activity of superoxide dismutasein left ventricle was markedly enhanced in PC three groups(P<0.05 or P<0.01).The results of electron microscope showed that PC could relieve myocardial damage induced by Iso.In vitro among the dose of 25,50,100 mg·L-1,PC prevented the proliferation of the CFb,decreased the quantification of Ⅰ、Ⅲ collagen and the expression of TGF-β1(P<0.05 or P<0.01).Conclusion PC can inhibit cardiac fibroblast proliferation and collagen synthesis through antioxidation,then inhibit myocardial fibrosis and protect myocardium in rats.