中南药学

目的 基于粪菌移植以及体外实验探究木犀草素通过“肠-肺”轴调控肺部炎症的机制。方法 BALB/c小鼠连续2周行木犀草素灌胃（1次/d），末次给药1 h后鼻内滴注脂多糖（LPS）构建急性呼吸窘迫综合征（ARDS）模型，造模24 h后观察支气管肺泡灌洗液（BALF）中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、转化生长因子-β1(TGF-β1)蛋白及mRNA表达、小鼠肠道菌群及粪便丁酸含量的变化，通过体外实验观察木犀草素对LPS细胞毒性和氧化损伤的保护作用。通过混合广谱抗菌药物构建伪无菌小鼠模型，分别灌胃给予正常小鼠和木犀草素处理小鼠粪菌悬液2周（1次/d），末次给药1 h后鼻内滴注LPS构建ARDS模型，造模24 h后观察小鼠肠道菌群及粪便丁酸含量变化，BALF中IL-6、TNF-α、TGF-β1蛋白及mRNA表达，谷胱甘肽（GSH）、丙二醛（MDA）和超氧化物歧化酶（SOD）水平。结果 木犀草素可缓解LPS造成的小鼠肺部IL-6、TNF-α和TGF-β1异常升高，肠道菌群失衡及粪便丁酸含量下调，人结肠上皮NCM460细胞的细胞毒作用和氧化损伤。经过木犀草素处理小鼠粪菌移植可调控ARDS小鼠肠道中Muribaculaceae、Xylanibacter和Marvinbryantia属相对丰度，上调粪便丁酸含量，下调小鼠肺部IL-6、TNF-α和TGF-β1水平，上调GSH和SOD水平，下调MDA水平。结论 木犀草素可通过“肠-肺”轴调控肺部炎症，可能与保护肠道屏障功能和维持肠道菌群平衡有关。

Objective To determine the mechanism of luteolin regulating lung inflammation through the gut-lung axis based on fecal microbiota transplantation. Methods BALB/c mice were orally administered luteolin(once/day) for 2 weeks. The acute respiratory distress syndrome mice model was established 1 h after the last treatment by lipopolysaccharide(LPS) intranasal instillation. After 24 h, the level of interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), transforming growth factor-β1(TGF-β1) in bronchoalveolar lavage fluid(BALF), gut microbiota and butyric acid in feces was measured. The protective effect of luteolin on the cellur toxicity and oxidative damage from LPS was observed. The pseudo germ-free(PGF) mouse model with was constructed by mixing broadspectrum antibiotics. The PGF mice with luteolin treatment or normal mice were orally administered fecal microbiota suspension from for 2 weeks. Then the mice model was established by LPS intranasal instillation. After 24 h, the microbiota, the level of IL-6, TNF-α, and TGF-β1 in BALF, the level of glutathione(GSH), malondialdehyde(MDA), and superoxide dismutase(SOD), the mRNA expression of IL-6, TGF-β1, and TNF-α in the lung tissue, and the level of butyric acid in the feces were detected. Results The abnormally increased level of IL-6, TGF-β1 and TNF-α, and imbalance of gut microbiota and butyric acid in the feces were relieved, and the cytotoxicity and oxidative damage from LPS were suppressed in human colonic epithelium NCM460 cells by luteolin. After fecal microbiota transplantation with luteolin treatment, the relative abundance of Muribaculaceae, Xylanibacter and Marvinbryantia was regulated and butyric acid was upregulated in the feces, the level of IL-6, TGF-β1 and TNF-α was downregulated in BALF, mRNA expression of IL-6, TGF-β1 and TNF-α, and the level of MDA were downregulated, the level of GSH and SOD was upregulated in the lung tissue. Conclusion The mechanism of luteolin regulating pneumonia is related to gut-lung axis, intestines barrier protection and gut microbiota balance.