洋甘菊提取物对脂多糖诱导的小鼠急性肺损伤的机制研究

Mechanism of Matricaria chamomile L. extract on lipopolysaccharide induced acute lung injury

中文关键词:  洋甘菊提取物  脂多糖  急性肺损伤  肺保护作用

英文关键词:Matricarla chamomilla L. extract  lipopolysaccharide  acute lung injury  protective effect

中文摘要:

      目的 研究洋甘菊提取物对脂多糖(lipopolysaccharide, LPS)诱导小鼠急性肺损伤(acute lung injury, ALI)的保护作用, 并探索洋甘菊提取物减轻ALI的作用机制。方法 本研究将48只雄性SPF级昆明小鼠随机分为6组, 分别是空白组、模型组、阳性对照组、洋甘菊提取物低剂量、中剂量、高剂量组, 每组8只。各组小鼠连续灌胃给药7 d, 阳性对照组腹腔注射给药地塞米松(dexamethasone, DEX) 5 mg/kg; 洋甘菊提取物低、中、高剂量组分别灌胃85、170和340 mg/(kg·d)洋甘菊提取物。除空白组由气管向肺内滴注生理盐水外, 其余各组均由气管向肺内滴注LPS的方式建立ALI模型。检测小鼠肺泡灌洗液(bronchoalveolar lavage fluid, BALF)中细胞因子肿瘤坏死因子α (tumor necrosis factor-α, TNF-α)、白细胞介素-6 (interleukin 6, IL-6)和白细胞介素-1β (interleukin 1β, IL-1β)、并对BALF沉淀物进行吉姆萨染色及白细胞计数; 摘眼球取血, 检测血清中丙二醛(malondialdehyde, MDA)和超氧化物歧化酶(superoxide dismutase, SOD)的含量; 取右肺下叶组织, 观察病理形态; 检测小鼠肺组织中Toll样受体4 (Toll-like receptor 4, TLR4)、髓样分化因子(recombinant myeloid differentiation factor 88, MyD88)、核因子κB (nuclear factor-kappa B, NF-κB)等表达水平。结果 与空白组相比, LPS模型组小鼠BALF中TNF-α、IL-6、IL-1β、白细胞计数和血清中MDA含量显著升高(P<0.05), 血清中SOD显著降低(P<0.05)。HE染色可见, 肺间质炎症浸润严重, 肺组织结构破坏和形态不正常, 肺组织的TLR4、MyD88、NF-κBp65表达水平升高(P<0.05)。与LPS模型相比, 各给药组小鼠BALF中的TNF-α、白细胞计数和血清中MDA含量显著降低(P<0.05), 血清中SOD显著升高(P<0.05), HE染色可见, 小鼠肺组织炎性细胞浸润减少, 肺泡腔较清晰, 肺组织形态较完整, 肺组织的TLR4、MyD88、NF-κBp65表达水平降低(P<0.05)。结论 洋甘菊提取物可以缓解LPS所诱导的肺部炎症反应与氧化应激的过度激活, 从而减轻小鼠ALI, 其中170 mg/(kg·d)剂量作用较好, 洋甘菊提取物可能通过调节TLR4/MyD88/NF-κB信号通路发挥作用。

英文摘要:

      Objective To investigate the protective effects of Matricarla chamomilla L. extract on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and explore the mechanism by which Matricarla chamomilla L. extract alleviates ALI. Methods Forty-eight male SPF Kunming mice were randomly divided into control group, LPS group, dexamethasone (DEX) group, and low, middle and high doses of Matricarla chamomilla L. extract groups. The mice in each group were first continuously administered by gastric gavage for 7 days, and dexamethasone was administered intraperitoneally in the dexamethasone group 5 mg/kg. Matricarla chamomilla L. extract was administered 85, 170 and 340 mg/(kg·d) for gastric lavage in the low, medium and high dose groups, respectively. Mice of all groups, except those of control group, were induced into ALI mouse model by intratracheal instillation of LPS. Subsequently, the mice were subjected to the determination of their levels of the inflammatory factors tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β) in bronchoalveolar lavage fluid (BALF) and perform Giemsa staining and white blood cell count on the BALF sediment. The content and activities of malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were detected. Lung tissue was taken and the pathological morphology of the inferior lobes of the right lung was observed. The expression levels of Toll-like receptor 4 (TLR4), recombinant myeloid differentiation factor 88 (MyD88), nuclear factor-kappa B (NF-κB) in lung tissue were detected. Results Compared with the blank group, the alveolar lavage fluid of LPS model group mice TNF-α, IL-6, IL-1β, White blood cell count and serum MDA content significantly increased (P<0.05), serum SOD significantly decreased (P<0.05), HE staining showed severe interstitial inflammation infiltration in the lungs, structural damage and abnormal morphology of lung tissue, protein expression levels of TLR4, MyD88, NF-κBp65 in lung tissue of mices increased (P<0.05). Compared with the LPS model, the levels in mice of each treatment group TNF-α, white blood cell count, and serum MDA contents were significantly reduced (P<0.05), while serum SOD content was significantly increased (P<0.05). HE staining showed a decrease in inflammatory cell infiltration in mouse lung tissue, clearer alveolar spaces, more complete lung tissue morphology, and protein expression levels of TLR4, MyD88 and NF-κBp65 in lung tissue of mice decreased (P<0.05). Conclusion Matricarla chamomilla L. extract can alleviate LPS induced pulmonary inflammation and overactivation of oxidative stress, thereby alleviating ALI in mice. Among them, a dose of 170 mg/(kg·d) has a better effect, and pathway such as TLR4/MyD88/NF-κB.