柚皮素对肺结核大鼠肺组织损伤的影响及其机制

Effect of naringenin on lung tissue damage in rats with pulmonary tuberculosis and its mechanism

目的探究柚皮素(NAR)对肺结核(PTB)大鼠肺组织损伤的影响及其机制。方法120只大鼠分为对照组(control)、模型组(PTB)、柚皮素低[25 mg/(kg·d)]、中[50 mg/(kg·d)]、高剂量[100 mg/(kg·d)]组和柚皮素高剂量+Colivelin[信号转导与转录激活因子3(STAT3)激活剂]组(NAR-H+Colivelin),每组20只。计算肺组织湿重/干重(W/D)比值;ELISA法检测干扰素-γ(IFN-γ)、白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)、白细胞介素-1β(IL-1β)、丙二醛(MDA)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)水平。苏木素-伊红(HE)染色观察肺组织病理变化;免疫组化检测α-平滑肌肌动蛋白(α-SMA)表达;Western blot检测IL-6和STAT3蛋白表达。结果与control组相比,PTB组肺组织损伤严重,肺泡结构紊乱、塌陷,有大量炎症细胞浸润,肺间质充血增厚;W/D比值、IL-6、IL-1β、TNF-α和IFN-γ、MDA水平及α-SMA、IL-6表达和STAT3磷酸化水平均增加(P<0.05),SOD和GSH-Px水平均降低(P<0.05)。与PTB组相比,NAR-L组、NAR-M组和NAR-H组大鼠肺组织损伤程度及炎症细胞浸润减轻;W/D比值、IL-6、IL-1β、TNF-α和IFN-γ、MDA水平及α-SMA、IL-6表达和STAT3磷酸化水平剂量依赖性降低(均P<0.05),SOD和GSH-Px水平剂量依赖性增加(均P<0.05)。Colivelin逆转了柚皮素对PTB大鼠肺组织损伤的保护作用(P<0.05)。结论柚皮素可能通过抑制IL-6/STAT3信号通路激活,改善肺结核大鼠肺组织损伤。

Objective To investigate the effect and mechanism of naringenin(NAR)on lung tissue damage in pulmonary tuberculosis(PTB)rats.Methods A total of 120 rats were randomized into control group,model group(PTB),low dose Naringenin group(NAR-L),medium dose Naringenin group(NAR-M),high dose Naringenin group(NAR-H),and high-dose Naringenin+Colivelin(STAT3 activator)group(NAR-H+Colivelin),with 20 in each group.After the establishment of PTB model,the rats in NAR-L,NAR-M and NAR-H groups were given 25,50 and 100 mg/(kg·d)NAR,respectively.The rats in NAR-H+Colivelin group were intraperitoneally given 100 mg/(kg·d)NAR and 1 mg/(kg·d)Colivelin.The intervention lasted 28 d.The ratio of wet to dry weight(W/D)of lung tissue was calculated.The levels of interferon-γ(IFN-γ),interleukin-6(IL-6),tumor necrosis factorα(TNF-α),interleukin-1β(IL-1β),malondialdehyde(MDA),superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)were detected by ELISA.The pathological changes of lung tissue were observed by hematoxylin-eosin(HE)staining.The expression ofα-smooth muscle actin(α-SMA)was detected by immunohistochemistry.The expressions of IL-6 and STAT3 proteins were detected by Western blot.Results Compared with control group,the lung tissue in PTB group was severely damaged,with disordered and collapsed alveolar structures,extensive infiltration of inflammatory cells,and thickening of the pulmonary interstitium.Compared with control group,W/D ratio,the levels of IL-6,IL-1β,TNF-α,IFN-γ,and MDA,the expressions ofα-SMA and IL-6,and the phosphorylation level of STAT3 were increased in PTB group(all P<0.05),while the levels of SOD and GSH-Px were decreased(all P<0.05).Compared with PTB group,the degree of lung tissue damage and inflammatory cell infiltration in NAR-L,NAR-M,and NAR-H groups were reduced.Compared with PTB group,W/D ratio,the levels of IL-6,IL-1β,TNF-α,IFN-γ,and MDA,the expressions ofα-SMA and IL-6,and the phosphorylation level of STAT3 were dose-dependently decreased in NAR-L,NAR-M,and NAR-H groups(P<0.05),while the levels of SOD and GSH-Px were increased in a dose-dependent manner(all P<0.05).Colivelin reversed the protective effect of naringenin against lung tissue injury in PTB rats(all P<0.05).Conclusion Naringenin may ameliorate the lung tissue injury in pulmonary tuberculosis rats by inhibiting IL-6/STAT3 signaling pathway.