目的 探究返魂草Senecio cannabifolius Less.多糖对哮喘大鼠的治疗作用及机制。方法 60只SD大鼠随机分为对照组、模型组、地塞米松组和返魂草多糖高、中、低剂量（400、200、100 mg·kg^-1）组，采用10%卵清蛋白（OVA）联合氢氧化铝佐剂建立哮喘模型，对照组、模型组给予等体积蒸馏水，连续ig给药14 d。记录大鼠体质量变化情况；苏木精-伊红（HE）染色观察气管、肺组织病理情况；肺功能仪检测以0、3.125、6.250、12.500、25.000、50.000 g·L^-1氯化乙酰甲胆碱（Mch）雾化下大鼠的气道阻力最大值（Max Rrs）；对支气管肺泡灌洗液（BALF）中炎症细胞进行分类及计数； ELISA法检测大鼠血清白细胞介素4（IL-4）、γ干扰素（IFN-γ）、免疫球蛋白E（IgE）、C-反应蛋白（CRP）、白细胞介素2（IL-2）、肿瘤坏死因子-α（TNF-α）含量；流式细胞术检测大鼠脾脏辅助性T细胞1（Th1）/辅助性T细胞2（Th2）的平衡状态；¹²⁵IPCR（qRT-PCR）检测大鼠肺组织中磷脂酰肌醇3-激酶（PI3K）、蛋白激酶B（Akt）、核因子κB p65（NF-κB p65） mRNA表达水平； Western blotting法检测大鼠肺组织PI3K/Akt通路和NF-κB p65活化情况。结果 与模型组相比，返魂草多糖高剂量组大鼠从实验第15天体质量显著增加（P＜0.01）；气管、肺组织病理变化显著改善；在Mch浓度为0、3.125、12.500、25.000、50.000 g·L^-1时，Max Rrs显著降低（P＜0.05、0.01）； BALF中总细胞数、白细胞、中性粒细胞数和嗜酸性粒细胞数均显著下降（P＜0.05、0.01）；血清IL-4、IFN-γ、CRP、IL-2、TNF-α水平显著下降（P＜0.01）；脾脏Th1显著升高（P＜0.01），Th2显著降低（P＜0.01）；肺组织PI3K、Akt、NF-κB p65 mRNA显著降低（P＜0.05、0.01），肺组织p-PI3K/PI3K、p-Akt/Akt、p-NF-κB p65/NF-κB p65蛋白显著降低（P＜0.05、0.01）；且返魂草多糖作用均呈剂量相关性。结论 返魂草多糖能缓解哮喘大鼠气管、肺组织病理损伤，降低血清炎症因子含量，改善哮喘症状，其机制可能与通过抑制NF-κB磷酸化及其上游的PI3K/Akt信号通路，改善Th1/Th2平衡状态相关。

Objective To investigate the therapeutic effects and the mechanism of action of Senecio cannabifolius polysaccharides in asthmatic rats. Methods 60 SD rats were randomly divided into control group, model group, dexamethasone group, and high, medium and low dosage groups (400, 200 and 100 mg·kg^-1) of Senecio cannabifolius polysaccharides, and the asthma model was established by using 10% ovalbumin (OVA) combined with aluminium hydroxide adjuvant, and equal volume of distilled water was given to the control group and the model group for ig 14 consecutive days. The changes in body mass of rats were recorded; Hematoxylin-eosin (HE) staining was used to observe the histopathology of airways and lungs; The maximum airway resistance (Max Rrs) of rats under nebulization with acetylcholine chloride (Mch) at concentrations of 0, 3.125, 6.250, 12.500, 25.000, and 50.000 g·L^-1 was detected by the pulmonary function instrument; inflammatory cells in bronchoalveolar lavage fluid (BALF) were classified and counted; The contents of interleukin-4 (IL-4), interferon-γ (IFN-γ), immunoglobulin E (IgE), C-reactive protein (CRP), interleukin-2 (IL-2), and tumor necrosis factor-α (TNF-α) in rat serum were detected by ELISA; The balance state of helper T cell 1 (Th1)/helper T cell 2 (Th2) in rat spleen was detected by flow cytometry; The mRNA expression levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and nuclear factor κB p65 (NF-κB p65) in rat lung tissue were detected by real-time fluorescence quantitative PCR (qRT-PCR); and the activation of PI3K/Akt pathway and NF-κB p65 in rat lung tissue was detected by Western blotting. Results Compared with the model group, the high-dose group of Senecio cannabifolius polysaccharides significantly increased the body weight of rats from the 15th day of the experiment (P < 0.01); the pathological changes of trachea and lung tissues were significantly improved; when the concentration of Mch was 0, 3.125, 12.500, 25.000, and 50.000 g·L^-1, Max Rrs was significantly reduced (P < 0.05, 0.01); the total cell count, white blood cells, neutrophils, and eosinophils in BALF were significantly decreased (P < 0.05, 0.01); the levels of IL-4, IFN-γ, CRP, IL-2, and TNF-α in serum were significantly decreased (P < 0.01); Th1 in the spleen was significantly increased (P < 0.01), and Th2 was significantly decreased (P < 0.01); the mRNA levels of PI3K, Akt, and NF-κB p65 in lung tissue were significantly decreased (P < 0.05, 0.01), and the protein levels of p-PI3K/PI3K, p-Akt/Akt, and p-NF-κB p65/NF-κB p65 in lung tissue were significantly decreased (P < 0.05, 0.01); and the effects of Senecio cannabifolius polysaccharides were dose-dependent. Conclusion Senecio cannabifolius polysaccharides can alleviate the pathological damage of trachea and lung tissues, reduce serum inflammatory factors and improve asthma symptoms in asthmatic rats, and it may play an anti-asthmatic role by inhibiting the phosphorylation of NF-κB and its upstream PI3K/Akt signalling pathway and improving the balance of Th1/Th2 cells.

R285.5

吉林省科技厅发展计划项目（20240602036RC）