益气化瘀化痰方对肺纤维化大鼠的干预作用及其机制*

目的: 探讨益气化瘀化痰方对由博来霉素(BLM)诱导的大鼠肺纤维化的影响及其可能的机制。方法: 采用气管内一次性注射盐酸博来霉素5 mg/kg诱导制备肺纤维化大鼠模型。将60只SPF级SD大鼠随机分为正常对照组、模型对照组、阳性对照组、益气化瘀化痰方低浓度组(低浓度组)、益气化瘀化痰方中浓度组(中浓度组)和益气化瘀化痰方高浓度组(高浓度组),每组10只。各中药治疗组在造模4周后分别采用益气化瘀化痰方低、中、高浓度制剂(3.6 ml/(kg·d))灌胃,阳性对照组给予醋酸氢化可的松(3.6ml/(kg·d))灌胃,正常对照组和模型对照组给予同等体积的生理盐水(3.6 ml/(kg·d))灌胃,每日1次。12周后处死各组大鼠,取大鼠肺组织,称量肺质量并计算肺系数,HE染色观察组织形态学改变,Masson染色观察胶原纤维沉积情况;蛋白免疫印迹(Western blot)检测各组大鼠肺组织中转化生长因子-β1(TGF-β1)、锌指蛋白转录因子(Snail1)、E-钙黏蛋白(E-cadherin)、纤连蛋白(Fibronectin)等蛋白表达水平;实时荧光定量PCR(qRT-PCR)检测组织TGF-β1、Snail1、E-cadherin、Fibronectin等mRNA表达水平。结果: ①与模型组比较,各药物干预组肺系数均有降低(P＜0.05);②与空白组比较,模型组肺纤维化明显;各药物干预组与模型组比较,各治疗组肺间质胶原沉积减少,肺纤维化程度减轻;③治疗各组与模型组比较,各治疗组大鼠肺组织TGF-β1、Snail1、Fibronectin蛋白表达均明显减少(P＜0.05),E-cadherin蛋白表达明显升高(P＜0.05);④低、高浓度组与中浓度组比较,尤以中浓度组表达结果最显著(P＜0.05);⑤中药治疗各组与阳性组比较,表达结果优于阳性组(P＜0.05);mRNA表达与蛋白表达趋势一致。结论: 益气化瘀化痰方能显著治疗博来霉素所致的大鼠肺纤维化,其机理可能是通过下调TGF-β1调控TGF-β/Snail信号通路表达抑制大鼠的上皮细胞-间充质转化,而改善大鼠肺纤维化。

Effects of Yiqi Huayu Hutan decoction on pulmonary fibrosis in rats and its mechanism

Objective: To investigate the effects of Yiqi Huayu Hutan decoction on pulmonary fibrosis of rats which induced by bleomycin. Methods: The rat model of pulmonary fibrosis was induced by intratracheal injection of bleomycin hydrochloride (5 mg/kg). Sixty SD rats were randomly divided into the normal group (group N), the model group (group M), the positive control group (group Y), group of low concentration (group LC), group of medium concentration (group MC) and group of high concentration of Yiqi Huayu Hutan decoction (group HC). After 4 weeks, the experimental groups were treated with low concentration decoction, medium concentration decoction and high concentration decoction respectively, and the Y group was treated with hydrocortisone acetate, the Group N and group M were treated with saline by intragastric administration. Twelve weeks later, rats were killed and the pathomorphism of pulmonary tissues of each group was observed by HE staining and Masson staining. Further, the expressions of transforming growth factor-β1(TGF-β1), Snail1, E-cadherin and Fibronectin in pulmonary tissues of each group were detected by qTR-PCR and Western blot. Results: Compared with the model group, the collagen sediment in the interstitial was reduced in the experimental groups, especially in the group of medium concentration, which was observed by HE staining and Masson staining .Compared with the model group, the expressions of TGF-β1, Snail1 and Fibronectin protein in pulmonary tissues of the treatment groups were decreased in the experimental group, especially in the group of medium concentration, which were detected by qRT-PCR and Western blot. Conclusion: Yiqi Huayu Hutan decoction can significantly improve the pulmonary fibrosis which is induced by bleomycin, and the mechanism is related to the inhibition of the expression of TGF-β/Snail pathway of transcription TGF-β1.