云南松松塔对LPS诱导急性肺损伤大鼠炎症和氧化应激的影响

Effects of pinecone of Pinus yunnanensis on inflammation and oxidative stress of rats with LPS⁃induced acute lung injury

目的考察云南松松塔提取物对脂多糖(LPS)诱导大鼠急性肺损伤的保护作用及其可能的作用机制。方法SD大鼠随机分为6组,阳性组灌胃给予1.5 mg/kg地塞米松,云南松松塔提取物低、中、高剂量组分别灌胃给予50、100、200 mg/kg云南松松塔提取物,正常组、模型组灌胃给予等容量生理盐水,每天1次,连续4 d。末次给药后1 h,腹腔注射10 mg/kg LPS诱导大鼠急性肺损伤,4 h后处死大鼠取各脏器,计算脏器指数,ELISA测定肺泡灌洗液(BALF)中炎症因子、氧化因子水平,RT⁃PCR测定肺组织TLR4/NF⁃κB信号通路分子mRNA相对表达。结果与模型组比较,云南松松塔高剂量组大鼠肺脏炎症因子和氧化因子水平、脾脏指数、肝脏指数和肾脏指数均降低(P<0.05,P<0.01),胸腺指数升高(P<0.01),肺组织肺泡壁和支气管壁炎症细胞数量减少,水肿和充血情况减轻;BALF中炎症细胞因子TNF⁃α、IL⁃6、IL⁃1β、TGF⁃β水平降低(P<0.01),IL⁃10水平升高(P<0.01),SOD活力增加(P<0.01),MDA、NO水平降低(P<0.01);云南松松塔高、中剂量组大鼠肺组织中TLR4、NF⁃κB、TNF⁃α、IL⁃6、IL⁃1β相对mRNA表达降低(P<0.01)。结论云南松松塔提取物可能通过抑制TLR4/NF⁃κB信号通路减轻LPS诱导的大鼠急性肺损伤。

AIM To investigate the protective effects of pinecone of Pinus yunnanensis Franch.extract(PE)on rats with acute lung injury(ALI)induced by lipopolysaccharide(LPS)and its possible mechanism.METHODS SD rats were randomly divided into 6 groups,with positive group receiving gavage of 1.5 mg/kg dexamethasone,Pinus yunnanensis Franch.groups receiving low⁃dose,moderate⁃dose and high⁃dose PE gavage(50,100,200 mg/kg),and control group and model group receiving gavage of equal volumes of physiological saline,once daily for 4 consecutive days respectively.Rats induced into ALI models with intraperitoneal LPS injection(10 mg/kg)1 h after last administration and all other rats were sacrificed 4 h later.Upon procured organs,following procedures were conducted:determination of levels of inflammatory cytokines and oxidative factors in bronchoalveolar lavage fluid(BALF)by ELISA,identification of relative mRNA expression in TLR4/NF⁃κB signaling pathway by RT⁃PCR,and calculation of relevant indexes.RESULTS Compared with the model group,high⁃dose PE group showed significantly declined levels of inflammation and oxidative stress and indices of lung,spleen,liver and kidney and increased thymus index;apparently decreased inflammatory cells in alveolar wall and bronchial wall of lung tissue,significantly attenuated edema and congestion;notably reduced levels of inflammatory cytokines TNF⁃α,IL⁃6,IL⁃1β,TGF⁃βand oxidative factors MDA and NO;and markedly increased levels of IL⁃10 and activity of anti⁃oxidative factor SOD.Significant decrease of relative mRNA expressions of TLR4,NF⁃κB,TNF⁃α,IL-6,IL-1βin rats lung tissues was observed in the moderate⁃dose and high⁃dose PE groups.CONCLUSION Extract of pinecone of P.yunnanensis ameliorates LPS⁃induced ALI of rats through inhibiting TLR4/NF⁃κB signaling pathway.