Gu Mengdi, Pang Zheng
Innovative Institute of Chinese Medicine and Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China.
Innovative Institute of Chinese Medicine and Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China.
Phytomedicine. 2025 Jun;141:156663. doi: 10.1016/j.phymed.2025.156663. Epub 2025 Mar 19.
The opportunistic pathogen Pseudomonas aeruginosa primarily causes infections in immunocompromised individuals. Luteolin, a natural flavonoid, is widely present in plants, which exerts various pharmacological activities, including anti-inflammatory and antimicrobial activities.
This study aimed to explore the therapeutic efficacy of luteolin and the underlying molecular mechanisms in treating the P. aeruginosa-induced acute pneumonia.
Network pharmacology was utilized to identify the core targets of luteolin for treating acute P. aeruginosa pneumonia. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were performed to dissect the potential effects of luteolin and the involved signaling pathways. Surface plasmon resonance (SPR) assay and molecular docking were employed for studying the binding affinities of luteolin with the key targets. Furthermore, we applied a mouse model of bacterial pneumonia for assessing the therapeutic effects of luteolin in vivo, and an in vitro infection model for specifically investigating the effects of luteolin on macrophages as well as the underlying mechanisms upon P. aeruginosa infection.
Network pharmacology identified TNF, IL-6, EGFR and AKT1 as the key targets of luteolin for treating acute P. aeruginosa pneumonia. Moreover, as revealed by GO and KEGG enrichment analysis, EGFR, MAPK and PI3K/AKT pathways were the potential pathways regulated the P. aeruginosa-induced inflammatory response. According to the in vivo results, luteolin effectively mitigated the P. aeruginosa-induced acute lung injury through reducing the pulmonary permeability, neutrophil infiltration, proinflammatory cytokine production (IL-1β, IL-6, TNF and MIP-2) and bacterial burden in lung tissues, which led to increased survival rate of mice. Furthermore, the luteolin-treated mice had diminished EGFR, PI3K, AKT, IκBα, NF-κB p65, ERK, c-Jun and c-Fos phosphorylation, down-regulated M1 macrophage marker levels (iNOS, CD86 and IL-1β) but up-regulated M2 macrophage marker levels (Ym1, CD206 and Arg1) in lung tissues. Consistently, the luteolin-pretreated macrophages exhibited reduced phosphorylation of these regulatory proteins, diminished proinflammatory cytokine production, and down-regulated expression of M1 macrophage markers, but up-regulated expression of IL-10 and M2 macrophage markers.
luteolin effectively suppressed the inflammatory responses and M1 macrophage polarization through inhibiting EGFR/PI3K/AKT/NF-κB and EGFR/ERK/AP-1 signaling pathways in the treatment of acute P. aeruginosa pneumonia. This study suggests that luteolin could be a promising candidate for development as a therapeutic agent for acute bacterial pneumonia.
机会致病菌铜绿假单胞菌主要在免疫功能低下的个体中引起感染。木犀草素是一种天然黄酮类化合物，广泛存在于植物中，具有多种药理活性，包括抗炎和抗菌活性。
本研究旨在探讨木犀草素治疗铜绿假单胞菌诱导的急性肺炎的疗效及其潜在分子机制。
利用网络药理学确定木犀草素治疗急性铜绿假单胞菌肺炎的核心靶点。进行基因本体论（GO）和京都基因与基因组百科全书（KEGG）富集分析，以剖析木犀草素的潜在作用及涉及的信号通路。采用表面等离子体共振（SPR）分析和分子对接研究木犀草素与关键靶点的结合亲和力。此外，我们应用细菌性肺炎小鼠模型评估木犀草素在体内的治疗效果，并应用体外感染模型具体研究木犀草素对巨噬细胞的影响以及铜绿假单胞菌感染后的潜在机制。
网络药理学确定肿瘤坏死因子（TNF）、白细胞介素-6（IL-6）、表皮生长因子受体（EGFR）和蛋白激酶B1（AKT1）为木犀草素治疗急性铜绿假单胞菌肺炎的关键靶点。此外，GO和KEGG富集分析显示，EGFR、丝裂原活化蛋白激酶（MAPK）和磷脂酰肌醇-3激酶/蛋白激酶B（PI3K/AKT）信号通路是调节铜绿假单胞菌诱导的炎症反应的潜在信号通路。体内实验结果表明，木犀草素通过降低肺组织通透性、中性粒细胞浸润、促炎细胞因子产生（IL-1β、IL-6、TNF和巨噬细胞炎症蛋白-2（MIP-2））以及细菌载量，有效减轻了铜绿假单胞菌诱导的急性肺损伤，从而提高了小鼠的存活率。此外，木犀草素治疗的小鼠肺组织中EGFR、PI3K、AKT、IκBα、核因子κB p65（NF-κB p65）、细胞外信号调节激酶（ERK）、c-Jun和c-Fos的磷酸化水平降低，M1巨噬细胞标志物水平（诱导型一氧化氮合酶（iNOS）、CD86和IL-1β）下调，但M2巨噬细胞标志物水平（Ym1、CD206和精氨酸酶1（Arg1））上调。同样，木犀草素预处理的巨噬细胞这些调节蛋白的磷酸化水平降低，促炎细胞因子产生减少，M1巨噬细胞标志物表达下调，但白细胞介素-10（IL-10）和M2巨噬细胞标志物表达上调。
在治疗急性铜绿假单胞菌肺炎中，木犀草素通过抑制EGFR/PI3K/AKT/NF-κB和EGFR/ERK/活化蛋白-1（AP-1）信号通路有效抑制炎症反应和M1巨噬细胞极化。本研究表明，木犀草素有望开发成为急性细菌性肺炎的治疗药物。
