白藜芦醇苷对大鼠肺间质纤维化的防治作用

Effects of polydatin on bleomycin-induced pulmonary fibrosis in rats

目的:建立博来霉素(BLM)诱导的大鼠肺间质纤维化的动物模型,分别给予3种剂量的白藜芦醇苷(PD),观察PD对大鼠肺间质纤维化的防治作用并探讨其可能的作用机制。方法:192只3月龄健康SD大鼠,随机分为正常对照组(A组),肺纤维化模型组(B组),PD低剂量组(C组),PD中剂量组(D组),PD高剂量组(E组),地塞米松组(F组)。每组于第3,7,14,28天各随机处死8只。光镜下观察肺组织形态学变化;观察肺组织匀浆中羟脯氨酸(HyP)含量,PLA2活性及支气管肺泡灌洗液(BALF)中前列腺素E2(PGE2),白三烯C4(LTC4)和转化生长因子-β1(TGF-β1)含量变化。结果:第3,7,14,28天,模型组肺组织匀浆中PLA2活性,BALF中的PGE2,LTC4和TGF-β1含量均较正常组显著增高(P<0.01),肺组织HyP含量于第7天开始较正常对照组增高(P<0.05),第28天达最高峰;与模型组比较,3种剂量的PD(10,20,40 mg.kg-1.d-1)及地塞米松在各观察时间点均可降低肺组织匀浆中PLA2活性和HyP含量及BALF中的PGE2,LTC4和TGF-β1含量(P<0.05);PD组间比较差异有统计学意义(P<0.05),其中上述指标E组低于D组,D组低于C组;E组与地塞米松组差异无统计学意义;但上述观察指标仍高于正常组(P<0.01)。病理组织形态学提示,PD各组及地塞米松组肺泡炎及肺纤维化程度较轻。结论:PD具有抑制肺间质纤维化的作用,但不能完全阻止其进展过程。

Objective： To observe the effects of three different doses of polydatin（PD） on pulmonary interstitial fibrosis in rats induced by bleomycin.Method： One hundred and twenty-nine healthy Sprague-Dawley rats three months old,were randomly divided into six groups.Group A： normal control group;group B： model group treated with bleomycin（pretreatment with saline 1 mL·kg-1 intraperitoneally before bleomycin）;group C： PD 10 mg·kg-1（pretreatment with PD 10 mg·kg-1 intraperitoneally before bleomycin）;group D： PD 20 mg·kg-1（pretreatment with PD 20 mg·kg-1 intraperitoneally before bleomycin）;group E： PD 40 mg·kg-1（pretreatment with PD 40 mg·kg-1 intraperitoneally before bleomycin）,group F： dexamethason（DXM） treated group（pretreatment with saline 1 mL·kg-1 intraperitoneally before bleomycin and then with DXM 1 mg·kg-1·d-1）.At day 3,7,14,28 after injection of bleomycin,eight rats in each group were randomly chosen to be killed.The right lungs of dead rats were removed and appropriately processed for hematoxylin and eosin（HE） stain,histologically observed under light microscope.The hydroxyproline content and the PLA2 activity in pulmonary homogenate were measured with alkaline hydrolysis assay and acid modified microtitrimetic method.The levels of leukotriene C4（LTC4）,prostaglandin E2（PGE2）,transforming growth factor-β1（TGF-β1） in bronchoalveolar lavage fluid（BALF） were measured with enzyme-linked immunosorbent assay（ELISA）.Result： At day 3,7,14,28 after intratracheal instillation of bleomycin in rats of group B,the PLA2 activity in lung homogenate and the levels of its metabolic products PGE2,LTC4 as well as TGF-β1 in BALF increased significantly compared with those in group A（P0.01）.And lung hydroxyproline concentration began to grow up markedly at day 7 compared with those in group A（P0.05）,reaching its maximum at day 28.Compared with group B,three different doses of PD and DXM significantly reduced the activity of the PLA2 and hydroxyproline concentration in lung homogenate as well as the levels of PGE2,LTC4,TGF-β1 in BALF at various periods（P0.05）.There was statistically significant difference between three different doses of PD groups（P0.05）.And the group E（PD 40 mg·kg-1） was lower than group D（PD 20 mg·kg-1）,group D was lower than group C（PD 10 mg·kg-1）（respectively,P0.01）.Group E and DXM group were no significant difference.However,all these observation parameters were higher than the normal level（compared with group A,P0.01）.Histological studies revealed that it was showed less inflammation and a lower degree of fibrosis in the lungs treated with PD than bleomycin model group.Conclusion： PD has the protective effect on pulmonary interstitial fibrosis.However,it can′t completely block the process of pulmonary fibrosis.