虾青素对肝纤维化大鼠的保护作用及机制研究*

目的 研究虾青素抑制肝纤维化作用是否与影响TGF-β1/Smad/ERK通路有关。方法 将50只大鼠随机分为正常组、模型组、秋水仙碱组（0.1 mg·kg^-1）、虾青素Ⅰ组（2 mg·kg^-1）和虾青素Ⅱ组（4 mg·kg^-1）,每组10只。采用皮下注射CCl₄法制备肝纤维化大鼠模型。在造模成功后,给予正常组和模型组动物生理盐水、而在药物干预组则分别给予秋水仙碱和虾青素灌胃,连续给药6 w。分别采用免疫组化法和Western blot法检测肝组织Ⅰ型胶原、Smad2、转化生长因子-β1（TGF-β1）和p-ERK蛋白表达,采用RT-PCR法检测肝组织CollagenⅠ、Smad2、TGF-β1 和p-ERK mRNA水平。结果 正常组、虾青素Ⅰ组和虾青素Ⅱ组肝组织Ⅰ型胶原蛋白分别为（0.4±0.1）、（1.4±0.3）和（1.2±0.3）,均显著低于模型组【（1.7±0.4）,P<0.05】,Smad2分别为（0.5±0.1）、（1.3±0.4）和（0.8±0.4）,显著低于模型组【（1.6±0.3）,P<0.05】,TGF-β1蛋白分别为（0.5±0.1）、（1.4±0.4）和（1.2±0.3）,显著低于模型组【（1.7±0.4）,P<0.05】,p-ERK蛋白分别为（0.4±0.1）、（1.3±0.4）和（0.9±0.3）,显著低于模型组【（1.6±0.5）,P<0.05】;正常组、虾青素Ⅰ组和虾青素Ⅱ肝组织Ⅰ型胶原 mRNA水平分别为（1.0±0.1）、（2.0±0.4）和（1.8±0.5）,均显著低于模型组【（2.4±0.4）,P<0.05】,Smad2 mRNA水平分别为（1.0±0.1）、（2.0±0.5）和（1.8±0.4）,显著低于模型组【（2.5±0.6）,P<0.05】,TGF-β1 mRNA水平分别为（1.0±0.1）、（2.1±0.4）和（1.6±0.3）,均显著低于模型组【（2.5±0.5）,P<0.05】,p-ERK mRNA水平分别为（1.1±0.1）、（2.1±0.4）和（1.8±0.3）,均明显低于模型组【（2.6±0.5）,P<0.05】。结论 虾青素可抑制肝纤维化进展,其机制可能与调控TGF-β1/Smad/ERK通路表达有关。

Inhibition of TGF-β1/Smad/ERK passway by astaxanthin in rats with CCl4-induced liver fibrosis

Objective To investigate the protective effect of astaxanthin on hepatic fibrosis and the mechanism by which the TGF-β1/Smad/ERK pathway involved. Methods 50 male SD rats were randomly divided into control,model,colchicine （0.1 mg·kg^-1）,astaxanthin group I （2 mg·kg^-1） and astaxanthin groupⅡ（4 mg·kg^-1）-intervened groups with 10 rats in each group. A rat model of hepatic fibrosis was established by subcutaneous injection of carbon tetrachloride. At 10th week of modeling,rats in each group were respectively given intragastric administration of colchicines or astaxanthin except in control and model with normal salt,for 6 weeks. The expression of type I collagen,Smad2,transforming growth factor-β1（TGF-β1） and p-ERK protein in liver tissues was detected by immunohistochemistry and Western blot,and the collagen I,Smad2,TGF- beta 1 and p-ERK mRNA in liver tissues was detected by RT-PCR. Results The collagen I protein in the liver tissues of control,astaxanthin group I and astaxanthin group II were （0.4±0.1）,（1.4±0.3） and （1.2±0.3）,respectively,significantly lower than [（1.7±0.4）,P<0.05] in the model,Smad2 protein was（0.5±0.1）,（1.3±0.4） and（0.8±0.4）,much lower than [（1.6±0.3）,P<0.05] in the model,TGF-β1 protein was（0.5±0.1）,（1.4±0.4） and （1.4±0.4）,significantly lower than[（1.7±0.4）,P<0.05] in the model,and the p-ERK protein was（0.4 ± 0.1）,（1.3±0.4） and（0.9±0.3）,respectively,also significantly lower than[（1.6±0.5）,P<0.05] in the model;the hepatic collagen I mRNA levels in the control,astaxanthin group I and astaxanthin group II were （1.0±0.1）,（2.0±0.4） and （1.8±0.5）,significantly lower than[（2.4±0.4）,P<0.05] in the model,the Smad2 mRNA were（1.0 ± 0.1）,（2.0±0.5） and （1.8±0.4）,significantly lower than[（2.5±0.6）,P<0.05] in the model,the TGF-β1 mRNA were（1.0±0.1）,（2.1±0.4） and （1.6±0.3）,much lower than [（2.5±0.5）,P<0.05] in the model,and the p-ERK mRNA levels were （1.1±0.1）,（2.1±0.4） and（1.8±0.3）,respectively,also significantly lower than[（2.6±0.5）,P<0.05] in the model. Conclusion Astaxanthin can inhibit the progression of hepatic fibrosis,which might be related to the down-regulation of TGF-β1/Smad/ERK pathway activation.