姜黄素对大鼠肺间质纤维化影响的机制研究

Research of the mechanism of curcuma on pulmonary fibrosis induced by bleomycin in rats

目的 研究姜黄素对大鼠肺间质纤维化的治疗作用及其可能机制.方法 健康雄性SD大鼠80只,随机分为对照组、模型组、泼尼松组和姜黄素组,每组20只.除正常对照组外,其余各组大鼠气管内一次性注入博来霉素诱导肺纤维化.造模后第15天起,姜黄素组和泼尼松组分别给予姜黄素（300 mg/kg）和泼尼松（5 mg/kg）每日灌胃一次,其余两组每日给予1%羧甲基纤维素钠（10 ml/kg）灌胃一次.各组动物分别于造模后第21、28、42及56天随机处死5只,取肺组织行HE、Masson染色评价肺组织病理变化,消化法测定肺组织羟脯氨酸（HYP）含量,免疫组化法测定肺组织转化生长因子β1（TGF-β1）、血小板源性生长因子（PDGF）的表达.结果 姜黄素组肺纤维化程度,肺组织HYP含量在第42和56天显著低于同期模型组[42 d：1.28±0.61 vs 2.28±0.39,P〈0.01;（1.73±0.22）mg/g vs（2.50±0.37）mg/g,P〈0.01;56 d：1.00±0.59 vs 1.73±0.36,P〈0.05;（1.57±0.36）mg/g vs（2.20±0.42）mg/g,P〈0.01],第42天姜黄素组HYP含量显著低于同期泼尼松组（P〈0.05）,肺组织TGF-β1、PDGF蛋白表达于造模后第28、42及56天显著低于模型组（28d：TGF-β1：3642.05±839.31 vs 5067.35±738.39,P〈0.05;PDGF：2957.55±739.16 vs 4457.75±568.39,P〈0.05;42 d：TGF-β1：2689.73±529.22 vs 4089.50±619.37,P〈0.01;PDGF：2834.46±567.16 vs 3239.52±628.26,P〈0.01;56 d：TGF-β1：1968.57±408.36 vs 2968.20±498.42,P〈0.01;PDGF：1083.36±381.35 vs 2019.40±412.36,P〈0.01）,第42、56天显著低于泼尼松组（42 d,TGF-β1：3529.07±981.35,PDGF：2618.34±813.34;56 d,TGF-β1：2530.83±439.37,PDGF：1738.35±536.62,P均〈0.05）,其中第56天时与对照组比较差异无统计学意义（P〉0.05）.结论 在博来霉素诱导的大鼠肺纤维化形成阶段应用姜黄素于预能有效减轻肺纤维化程度,可能机制为姜黄素抑制了TGF-β1、PDGF蛋白在肺组织的表达.

Objective To observe the possible mechanism and inhibitory effects of curcumin on pulmonary fibrosis induced bleomycin in rats at the fibrosing stage. Methods 80 male Sprague-Dawley rats were random divided into 4 groups （20 rats in each group）. Rats in the fibrosis model group, the prednisone group and the curcumin group were induced by instilled bleomycin through tracheal, rats in the control group with same volume normal saline. Since the 15th day after bleomycin administration, the curcumin group and prednisone group were given curcumin （300 mg/kg） or prednisone （5mg/kg） per day by intragastric administration, respectively. The normal control group and the model group were given 1% sodium carboxymethyl cellulose （ 10ml/kg）. Six rats of each group were random sacrificed on the 21st, 28th, 42nd and 56th days after bleomycin administration. The histological changes of the pulmonary were evaluated by H. E and Masson dyeing. The expressions of transforming growth factor-β1 （TGF-β1）, platelet-derived growth factor （PDGF） and hydroxyproline in the tissue of pulmonary were assessed by immunohistochemistry and digestion method. Results Pulmonary fibrosis and hydroxyproline level in the curcumin group were obviously reduced as compared with the model group on the 42nd and 56th day[42 d：1. 28 ±0. 61 vs 2. 28 ±0. 39,P 〈0. 01 ;（1.73 ±0. 22）mg/g vs （2.50 ±0. 37） mg/g, P 〈0.01;56 d：1.00 ±0.59 vs 1.73 ±0.36, P〈 0. 05; （ 1.57 ± 0. 36） mg/g vs （2. 20 ± 0. 42） mg/g, P 〈 0. 01 ], and it was also lower than that in prednisone group on the 42nd day（ P 〈 0. 05 ）. The expression of TGF-β1 and PDGF in the curcumin group were obviously lower than that in the model group on the 28th, 42nd and 56th day[28 d：TGF-β1 ：3642. 05 ±839. 31 vs 5067. 35 ±738. 39, P 〈0. 05 ;PDGF：2957. 55 ±739. 16 vs 4457. 75 ±568. 39, P 〈0. 05;42 d： TGF-β1： 2689. 73 ± 529.22 vs 4089. 50 ± 619. 37, P 〈 0. 01; PDGF： 2834. 46 ± 567. 16 vs 3239. 52 ±628. 26, P 〈0. 01 ;56 d：TGF-β1： 1968.57 ±408. 36 vs 2968.20 ±498.42, P 〈0. 01 ;PDGF： 1083.36 ±381.35 vs 2019. 40 ±412. 36, P 〈0. 01 ], which was lower than that in prednisone group on the 42nd and 56th day （42 d,TGF-β1 ：3529. 07 ±981.35,PDGF：2618. 34 ±813. 34;56 d,TGF-β1 ：2530. 83 ±439. 37,PDGF： 1738. 35 ±536. 62, Pall 〈0. 05 ） , and it had no obvious difference compared with control group on the 56th day （ P 〉 0. 05 ）. Conclusion Curcumin could alleviate bleomycin-induced pulmonary fibrosis in rats at the fibrosing stage by inhibiting the expressions of TGF-β1 and PDGF.