金合欢素对哮喘幼年大鼠的改善作用及机制

Improvement effect of acacetin on juvenile asthma rats and its mechanism

目的基于沉默信息调节因子1(SIRT1)/AMP活化蛋白激酶(AMPK)信号通路探讨金合欢素对哮喘幼年大鼠的改善作用及机制。方法将幼年SD大鼠随机分为对照组、哮喘组、金合欢素组(13.33 mg/kg,灌胃)、SIRT抑制剂EX-527组(1 mg/kg,腹腔注射)、金合欢素+EX-527组(13.33 mg/kg金合欢素,灌胃+1 mg/kg EX-527,腹腔注射),每组12只(雌雄各半)。除对照组外,其余各组大鼠以腹腔注射卵清蛋白致敏+雾化吸入卵清蛋白增敏的方式复制哮喘模型。造模后,各药物组大鼠灌胃或(和)腹腔注射相应药液,每天1次,持续2周。末次给药后,检测其支气管肺泡灌洗液(BALF)中细胞总数、嗜酸性粒细胞数占比和白细胞介素5(IL-5)、IL-4、肿瘤坏死因子α(TNF-α)水平,观察肺组织病理形态学变化和杯状细胞异常增生情况,检测肺组织中丙二醛(MDA)、超氧化物歧化酶(SOD)水平,以及SIRT1、AMPK和过氧化物酶体增殖物激活受体γ共激活因子1α(PGC-1α)蛋白的表达情况。结果与对照组比较,哮喘组大鼠肺组织中有大量的炎症细胞浸润和明显的杯状细胞异常增生;BALF中细胞总数、嗜酸性粒细胞数占比和IL-5、IL-4、TNF-α水平,肺组织过碘酸希夫染色(PAS)评分,以及肺组织中MDA水平均显著升高(P<0.05);肺组织中SOD水平、SIRT1、PGC-1α蛋白的表达水平和AMPK蛋白的磷酸化水平均显著降低(P<0.05)。与哮喘组比较,金合欢素组大鼠肺组织的病理改变和杯状细胞异常增生均有所减轻,各定量指标均显著改善(P<0.05),而EX-527组大鼠肺组织的病理改变和杯状细胞异常增生均有所加重,各定量指标均显著恶化(P<0.05);联用EX-527可显著逆转金合欢素对哮喘幼年大鼠氧化应激及气道炎症的改善作用。结论金合欢素可抑制哮喘幼年大鼠的氧化应激和气道炎症,上述作用可能与激活SIRT1/AMPK信号通路有关。

OBJECTIVE To explore the improvement effect and mechanism of acacetin on juvenile asthma rats based on the silence information regulator 1(SIRT1)/AMP-activated protein kinase(AMPK)signaling pathway.METHODS Juvenile SD rats were randomly divided into control group,asthma group,acacetin group(13.33 mg/kg,gavage),SIRT inhibitor EX-527 group(1 mg/kg,intraperitoneal injection)and acacetin+EX-527 group(13.33 mg/kg acacetin,gavage+1 mg/kg EX-527,intraperitoneal injection),with 12 rats in each group(half male and half female).Except for the control group,the other groups were sensitized by intraperitoneal injection of ovalbumin and nebulized inhalation of ovalbumin to induce the asthma model.After modeling,rats in each drug group were orally administered or(and)intraperitoneally injected with the corresponding medication once a day for 2 weeks.After the last administration,the total number of cells,the proportion of eosinophils,and the levels of interleukin-5(IL-5),IL-4 and tumor necrosis factor-α(TNF-α)in the bronchoalveolar lavage fluid(BALF)were measured.The pathological changes and abnormal proliferation of goblet cells in lung tissue were observed,the levels of malondialdehyde(MDA)and superoxide dismutase(SOD)in lung tissue and the protein expressions of SIRT1,AMPK and peroxisome proliferator activated receptor-gamma co-activator factor-1α(PGC-1α)were detected.RESULTS Compared with control group,there was a large number of inflammatory cell infiltration and obvious goblet cell dysplasia in the lung tissue of rats in asthma group;the total number of cells in BALF,the proportion of eosinophils,the levels of IL-5,IL-4 and TNF-αin BALF,PAS score and MDA level in the lung tissue were significantly increased(P<0.05);the SOD level,protein expressions of SIRT1 and PGC-1αand protein phosphorylation level of AMPK in lung tissue were significantly decreased in asthma group(P<0.05).Compared with the asthma group,the pathological changes of lung tissue and goblet cell dysplasia of rats were reduced,and all quantitative indexes were significantly improved in acacetin group(P<0.05),while the pathological changes of lung tissue and goblet cell dysplasia of rats were increased,and all quantitative indexes were significantly worsened in EX-527 group(P<0.05).The combination of EX-527 could significantly reverse the effects of acacetin on oxidative stress and airway inflammation in juvenile asthma rats.CONCLUSIONS Acacetin can inhibit oxidative stress and airway inflammation in juvenile asthma rats,which may be related to the activation of the SIRT1/AMPK signaling pathway.