积雪草苷通过抑制炎症和纤维化减弱平阳霉素诱导的肺间充质纤维化（英文）

Asiaticoside attenuates bleomycin-induced interstitial pulmonary fibrosis

目的研究积雪草苷对平阳霉素诱导的大鼠肺间充质纤维化的治疗效果及其潜在机制。方法雄性SD大鼠分为正常对照组、模型组和治疗组;模型组和治疗组均给予平阳霉素诱导肺间充质纤维化;治疗组给予积雪草苷灌胃处理。HE染色和Masson染色用于分析肺组织的病理变化;化学方法检测肺组织匀浆中羟脯氨酸含量;酶联免疫吸附法检测大鼠血清中γ干扰素(IFN-γ),白细胞素介素4(IL-4)和肿瘤坏死因子α(TNF-α)的含量;免疫组化检测转化生长因子β_1(TGF-β_1)和腺苷A2受体(A2AR)在肺组织中的表达;Western蛋白印迹法检测TGF-β_1和A2AR蛋白表达。结果在实验的第7天、第14天和第28天,模型组的肺组织炎症评分显著高于对照组(P<0.01),而积雪草苷组的肺组织炎症较模型组减轻(P<0.01,P<0.05);与正常对照组相比,模型组的肺纤维化评分显著高于对照组(P<0.01),而积雪草苷组的肺纤维化程度较模型组得到改善(P<0.05);在实验的第14天和第28天,模型组大鼠肺组织的羟脯氨酸含量[1.85±0.10,(2.48±0.18)mg·g^(-1)]较正常对照组[0.79±0.07,(0.84±0.08)mg·g^(-1)]升高(P<0.01),但在积雪草苷组羟脯氨酸含量[1.32±0.131,(1.71±0.13)mg·g^(-1)]较模型组降低(P<0.05);积雪草苷组IL-4,TNF-α的含量低于模型组(P<0.05),而模型组IL-4和TNF-α的含量高于正常对照组(P<0.01,P<0.05);积雪草苷组TGF-β_1蛋白表达较模型组降低(P<0.05),A2AR蛋白表达较模型组升高,而模型组TGF-β_1的蛋白表达较正常对照组升高(P<0.05),A2AR蛋白表达较正常对照组降低(P<0.05)。结论积雪草苷通过降低IL-4,TNF-α和TGF-β_1的表达,提高A2AR的表达水平来抑制肺组织炎症和基质累积,改善平阳霉素诱导的间充质性肺纤维化。

OBJECTIVE To study the therapeutic effect and the underlying mechanism of asiaticoside on bleomycin-induced rat interstitial pulmonary fibrosis（IPF）.METHODS Male Sprague-Dawley（SD） rats were divided into normal control group,bleomycin 5 mg·kg^（-1） model group and asiaticoside50 mg·kg^（-1） group.The model and asiaticoside group were administrated with bleomycin 5 mg·kg^（-1） to induce IPF,while the asiaticoside group was administrated with asiaticoside 50 mg·kg^（-1） by gastric perfusion.Hematein eosin（HE） and Masson staining were carried out to analyze the histopathological changes in the lung.Lung homogenates were used to examine hydroxyproline（HYP） content,and serum samples were used to measure the concentration of interferon-γ（IFN-γ）,interleukin-4（IL-4） and tumor necrosis factor-α（TNF-α）.In addition,immunohistochemical methods were used to locate lung transforming growth factor-β_1（TGF-β_1） and adenosine 2A receptor（A2AR） expression,and Western blotting was used to examine the expression levels of TGF-β_1 and A2 AR.RESULTS On the 7th,14 th and 28 th days,the scores of pulmonary inflammation were higher in model group than in control group（P〈0.01）,and the asiaticoside group showed mitigated alveolitis（P〈0.01,P〈0.05） compared with model group.Compared with control group,the scores of pulmonary fibrosis in model group were elevated（P〈0.01）,and the asiaticoside group showed reduced pulmonary fibrosis（P〈0.05）.On the14 th and 28 th days,HYP content in the model group[1.85±0.10,（2.48±0.18）mg·g^（-1）]was higher than in the control group[0.79±0.07,（0.84±0.08）mg·g^（-1）]（P〈0.01）,but HYP content in the asiaticoside group[1.32±0.131,（1.71±0.13）mg·g^（-1）]was lower than in the model group（P〈0.05）.IL-4 and TNF-αin the asiaticoside group were lower than in model group（P〈0.05）,but were higher in the model group than in the control group（P〈0.01,P〈0.05）.The expression level of TGF-β_1 protein in the asiaticoside group was lower than in the model group（P〈0.05）,but was higher in the model group than in the control group（P〈0.05）.The expression level of A2 AR protein in the asiaticoside group was higher than in the model group（P〈0.05）,but was lower in the model group than in the control group（P〈0.05）.CONCLUSION Asiaticoside can mitigate bleomycin-induced IPF by inhibiting the expression of IL-4,TNF-α and TGF-β_1,and raising the level of A2 AR.