鱼腥草素钠对小鼠急性肺损伤的保护作用及其对肠道菌群的影响

Protective effects of sodium houttuyfonate on acute lung injury in mice and its impact on gut microbiota

关键词:  急性肺损伤  鱼腥草素钠  肠道菌群  炎症

Key words:  acute lung injury  sodium houttuyfonate  gut microbiota  inflammation

摘要:

[目的] 探讨鱼腥草素钠（SH）对脂多糖（LPS）诱导的急性肺损伤（ALI）小鼠肠道菌群的影响及其可能作用机制。[方法] 18只SPF 级雄性 BALB/c小鼠（6~8 周龄，体质量 18~22 g）随机分为对照组、模型组（LPS组）和SH组（LPS+SH），每组6只。对照组和LPS组灌胃生理盐水，SH组灌胃SH（100 mg/kg），每日1次，除对照组外，模型组和SH组连续给药7 d后气管内注射5 mg/kg LPS建立ALI模型。小鼠建模前后称质量，实验结束后测定肺湿质量/干质量（W/D）比，苏木精-伊红（HE）染色观察病理变化，酶联免疫吸附测定（ELISA）炎症因子水平，蛋白质免疫印迹测定JNK/p38信号通路蛋白水平，采用16S rRNA分析肠道菌群。[结果] SH能降低LPS诱导的ALI小鼠的W/D比值，改善肺组织病理损伤，抑制肺组织中髓过氧化物酶（MPO）活性、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）及白细胞介素-6（IL-6）的水平，抑制p-JNK和p-P38蛋白表达。SH显著改善ALI小鼠的肠道菌群α和β多样性，Firmicutes的相对丰度升高，而Proteobacteria的相对丰度降低，在属的水平上，模型组unidentified_Enterobacteriaceae、Bacteroides和Klebsiella的相对丰度增加，而 Ligilactobacillus、Lactobacillus 和 Akkermansia 的丰度降低，而在SH组观察到了相反的趋势。炎症指标及肺水肿与Proteobacteria、Klebsiella和g_unidentified_Enterobacteriaceae呈正相关，与Akkermansia、Lactobacillus和Ligilactobacillus呈负相关。[结论] SH在LPS诱导的ALI中具有保护作用，其潜在机制可能是通过抑制JNK/p38信号通路炎症反应，以及改善肠道菌群紊乱。

Abstract:

[Objective] To investigate the effects of sodium houttuyfonate（SH） on gut microbiota in a mouse model of lipopolysaccharide（LPS）-induced acute lung injury（ALI） and explore its potential mechanisms of action. [Methods] Eighteen male SPF-grade BALB/c mice（6~8 weeks old，weighing 18~22 g） were randomly divided into three groups：control，model（LPS），and SH（LPS+SH），with six mice in each group. The control and LPS groups received oral gavage of normal saline，while the SH group received SH（100 mg/kg） once daily. Except for the control group，the model and SH groups were intratracheally injected with 5 mg/kg LPS after 7 days of continuous treatment to establish the ALI model. Mice were weighed before and after modeling. At the end of the experiment，lung wet-to-dry（W/D） ratios were measured，histopathological changes were observed using hematoxylin and eosin（HE） staining，inflammatory cytokine levels were assessed by enzyme-linked immunosorbent assay（ELISA），protein expression levels in the JNK/p38 signaling pathway were determined by Western blot，and gut microbiota composition was analyzed using 16S rRNA sequencing. [Results] SH reduced the W/D ratio，improved histopathological damage in lung tissue，and inhibited myeloperoxidase（MPO） activity，tumor necrosis factor-α（TNF-α），interleukin-1β（IL-1β），and interleukin-6（IL-6） levels in lung tissue. It also suppressed the expression of p-JNK and p-p38 proteins. SH significantly enhanced the α and β diversity of gut microbiota in ALI mice. The relative abundance of Firmicutes increased，while that of Proteobacteria decreased. At the genus level，the model group exhibited higher relative abundances of unidentified_Enterobacteriaceae，Bacteroides and Klebsiella，and lower abundances of Ligilactobacillus，Lactobacillus and Akkermansia，whereas the opposite trend was observed in the SH group. Inflammatory markers and pulmonary edema positively correlated with Proteobacteria，Klebsiellaand g_unidentified_Enterobacteriaceae，and negatively correlated with Akkermansia，Lactobacillus and Ligilactobacillus. [Conclusion] SH exerts protective effects against LPS-induced ALI，potentially through inhibiting inflammatory responses mediated by the JNK/p38 signaling pathway and restoring gut microbiota balance.