Objective

Astragaloside IV (AS IV) is antioxidant and anti-inflammatory product, which is extracted from the Chinese herb Astragalus membranaceus. It is widely used in a variety of inflammatory diseases. The research was to explored the protective effects of AS IV against lung injury induced by particulate matter 2.5 (PM2.5) in vivo.

Subjects and methods

Thirty-five male Sprague-Dawley rats were randomly divided into five groups (n=7 per group). (1) Normal saline group (NS), (2) AS IV group (AS) (100 mg/kg), (3) PM2.5 group (PM2.5), (4) PM2.5 + AS IV group (ASL) (50 mg/kg), and (5) PM2.5 + AS IVgroup (ASH) (100 mg/kg). Rats were pre-treated with AS IV intraperitoneally (50 and 100 mg/kg/day) for three days. Then, PM2.5 (7.5 mg/kg) was given by intratracheal instillation to induce lung injury. Six hours after PM2.5 stimulation, the rats were euthanized. Bronchoalveolar lavage fluid (BALF) was collected for assay of cytokines. Lung tissue was collected for oxidative stress, histology, immunohistochemistry, transmission electron microscope, and western blot analyses.

Results

AS IV alleviated PM2.5-induced lung injury by decreasing lung dry-wet ratio, reducing the level of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) in BALF, and reduced oxidative stress response in lung tissue. Western blot results revealed that AS-IV regulated the expression of TLR4/MyD88/NF-κB pathway proteins in lung tissues.

Conclusion

AS IV mitigated PM2.5 induced lung injury by regulating the activity of TLR4/MyD88/NF-κB signalling pathway, reducing inflammatory and oxidative stress responses.

中文翻译：

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黄芪甲苷IV通过调节TLR4 / MyD88 /NF-κB信号通路减轻PM2.5诱导的大鼠肺损伤

目的

黄芪甲苷IV（AS IV）是抗氧化剂和消炎产品，是从中草药黄芪中提取的。它广泛用于各种炎症性疾病。该研究旨在探讨AS IV对体内由颗粒物2.5（PM2.5）引起的肺损伤的保护作用。

主题与方法

将35只雄性Sprague-Dawley大鼠随机分为五组（每组n = 7）。（1）生理盐水组（NS），（2）AS IV组（AS）（100 mg / kg），（3）PM2.5组（PM2.5），（4）PM2.5 + AS IV组（ ASL）（50 mg / kg）和（5）PM2.5 + AS IVgroup（ASH）（100 mg / kg）。大鼠腹膜内接受AS IV预处理（50和100 mg / kg /天）三天。然后，通过气管内滴注给予PM2.5（7.5 mg / kg）以引起肺损伤。PM2.5刺激后六小时，对大鼠实施安乐死。收集支气管肺泡灌洗液（BALF）进行细胞因子分析。收集肺组织用于氧化应激，组织学，免疫组织化学，透射电子显微镜和蛋白质印迹分析。

结果

AS IV通过降低肺干湿比，降低白介素6（IL-6），肿瘤坏死因子α（TNF-α）和C反应蛋白（CRP）的水平来减轻PM2.5诱导的肺损伤并降低肺组织的氧化应激反应。蛋白质印迹结果表明，AS-IV调节肺组织中TLR4 / MyD88 /NF-κB通路蛋白的表达。

结论

AS IV通过调节TLR4 / MyD88 /NF-κB信号通路的活性，减轻炎症和氧化应激反应，减轻了PM2.5诱导的肺损伤。