山柰酚对慢性阻塞性肺疾病大鼠气道炎症反应的影响

Effects of kaempferol on airway inflammation in rats with chronic obstructive pulmonary disease

目的研究山柰酚改善慢性阻塞性肺疾病(COPD)大鼠气道炎症反应的作用机制。方法将24只雄性SD大鼠随机分为对照组、模型组(暴露于二手烟环境中,为期36周)和实验组(暴露于二手烟环境第7天起灌胃给予20 mg·kg^(-1)山柰酚),每组8只。用小动物肺功能检测系统测量肺功能;根据体质量与肺质量计算肺指数,以组织学观察肺组织炎症浸润和纤维化变化,以酶联免疫吸附试验(ELISA)法检测肺泡灌洗液中白细胞介素-1(IL-1)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的表达,以试剂盒检测超氧化物歧化酶(SOD)和丙二醛(MDA)表达,用蛋白质印迹法检测肺组织Toll样受体4(TLR4)和核因子-κB(NF-κB)p65蛋白表达水平。结果对照组、模型组和实验组的最大呼气流量分别为(19.48±1.61)、(15.86±1.00)和(18.07±0.83)mL·s^(-1),Valsalva动作分别为(231.22±10.26)、(244.94±9.32)和(225.71±3.80)mL·min^(-1),肺顺应性分别为(0.53±0.08)、(0.29±0.02)和(0.48±0.03)mL·cm^(-1)H_(2)O,总气道阻力分别为(0.19±0.12)、(0.21±0.01)和(0.20±0.01)cmH_(2)O·mL^(-1)·s^(-1),跑步经济性为(0.19±0.01)、(0.26±0.03)和(0.21±0.01)mL·s^(-1),肺质量分别为(2.76±0.10)、(2.94±0.18)和(2.29±0.26)g,体质量分别为(375.13±23.55)、(243.00±26.75)和(325.38±23.80)g,肺指数为0.74±0.02、1.22±0.09和0.70±0.05,肺泡灌洗液(BALF)中的炎性因子IL-1分别为(32.39±3.37)、(161.88±9.02)和(66.44±6.81)pg·mL^(-1),IL-6分别为(75.07±8.87)、(129.58±13.29)和(99.94±9.92)pg·mL^(-1),TNF-α分别为(441.76±9.92)、(814.47±122.02)和(656.70±70.06)pg·mL^(-1),MDA分别为(135.73±6.20)、(179.05±15.18)和(149.40±13.83)nmol·mL^(-1),SOD分别为(4258.55±384.12)、(1232.24±237.08)和(2134.33±197.99)U·mL^(-1),肺组织中TLR4蛋白表达水平为0.98±0.02、1.55±0.04和1.34±0.02,NF-κB p65蛋白表达水平为0.98±0.02、1.61±0.03、1.09±0.03。以上指标,模型组与对照组相比较,实验组与模型组相比较,在统计学上差异均有统计学意义(均P<0.05)。结论山柰酚通过抑制TLR4/NF-κB信号通路改善COPD大鼠气道炎症反应引起的肺损伤。

Objective To explore the mechanism of kaempferol in improving airway inflammation in chronic obstructive pulmonary disease(COPD)rats.Methods Twenty-for male SD rats were randomly divided into control group,model group(exposed to second-hand sm ok e for 36 weeks)and experimental group(intragastric administration of 20 mg·kg^(-1)kaempferol from the 7th day of exposure to secondhand smoke).Pulmonary function was measured by small animal pulmonary function test system,lung index was calculated by body weight and lung weight,inflammatory infiltration and fibrosis changes in lung tissue were observed histologically,the expression of interleukin-1(IL-1),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in bronchoalveolar lavage fluid was detected by enzyme linked immunosorbent assay(ELISA);the expression of superoxide dismutase(SOD)and malondialdehyde(MDA)was detected by the detection kit;and the protein expression of Toll-like receptor 4(TLR4)and nuclear factor-κB(NF-κB)p65 in lung tissue was detected by Western blotting.Results The peak expiratory flow in the control group,model group and experimental group were(19.48±1.61),(15.86±1.00)and(18.07±0.83)mL·s^(-1);valsalva maneuver were(231.22±10.26),(244.94±9.32)and(225.71±3.80)mL·min^(-1);lung compliance were(0.53±0.08),(0.29±0.02)and(0.48±0.03)mL·cm^(-1) H_(2)O;total airway resistance were(0.19±0.12),(0.21±0.01)and(0.20±0.01)cmH_(2)O·mL^(-1);running economy were(0.19±0.01),(0.26±0.03)and(0.21±0.01)mL·s^(-1);lung weight were(2.76±0.10),(2.94±0.18)and(2.29±0.26)g;body weight were(375.13±23.55),(243.00±26.75)and(325.38±23.80)g;lung index were 0.74±0.02,1.22±0.09 and 0.70±0.05;the expression levels of cytokines IL^(-1)in bronchoalveolar lavage fluid(BALF)were(32.39±3.37),(161.88±9.02)and(66.44±6.81)pg·mL^(-1);IL-6 were(75.07±8.87),(129.58±13.29)and(99.94±9.92)pg·mL^(-1);TNF-αwere(441.76±9.92),(814.47±122.02)and(656.70±70.06)pg·mL^(-1);MDA expression were(135.73±6.20),(179.05±15.18)and(149.40±13.83)nmol·mL^(-1);SOD expression were(4258.55±384.12),(1232.24±237.08)and(2134.33±197.99)U·mL^(-1);TLR4 protein expression level in lung tissue were 0.98±0.02,1.55±0.04,1.34±0.02;NF-κB p65 protein expression level were 0.98±0.02,1.61±0.03,1.09±0.03;the above indicators,control group compared with model group,experimental compared with and model group,the differences were all statistically significant(all P<0.05).Conclusion Kaempferol ameliorates lung injury induced by airway inflammation in COPD rats by inhibiting TLR4/NF-κB signaling pathway.