目的 研究白首乌乙醇提取物（ethanol extract of Cynanchum auriculatum，EECA）对干燥综合征（Sjögren’s syndrome，SS）小鼠模型颌下腺功能障碍的影响及其潜在机制。方法 采用LC-MS鉴定EECA的化学成分。用颌下腺自身抗原免疫C57BL/6小鼠，建立SS小鼠模型，设置对照组、模型组、硫酸羟氯喹（0.03 g/kg）组和EECA低、中、高剂量（0.4、0.8、1.6 g/kg）组，给予药物干预60 d。给药期间记录唾液分泌量和饮水量，采用流式细胞术检测各组小鼠脾脏中记忆B细胞数量和Th1/Th2细胞比例；采用苏木素-伊红（hematoxylin-eosin staining，HE）染色评估各组小鼠颌下腺组织病理变化；检测血清中细胞因子[白细胞介素-1β（interleukin-1β，IL-1β）、IL-17、肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）、γ干扰素（interferon-γ，IFN-γ）、IL-4]、免疫球蛋白[免疫球蛋白G（immunoglobulin G，IgG）、IgA、IgM]和抗血清淀粉样蛋白A（serum amyloid A，SSA）抗体、抗SSB抗体水平；采用免疫组化检测颌下腺组织水通道蛋白5（aquaporin 5，AQP5）的分布表达情况；采用Western blotting测定颌下腺组织中AQP5、p65、p-p65、抑制因子激酶α（inhibitor of kappa B kinase α，IKKα）和p-IKKα蛋白表达；采用qRT-PCR检测颌下腺组织中螺旋环螺旋结构域扩散激酶基因（Chuk）、核因子-κB二聚体基因（Rela）、AQP5 mRNA表达。结果 EECA能显著升高记忆B细胞数量（P＜0.01），调节Th1/Th2细胞比例，从而调控SS小鼠的异常免疫反应。EECA能显著降低SS小鼠血清中IL-1β、IL-17、TNF-α、IFN-γ、IL-4、IgG、IgA、IgM、抗SSA抗体、抗SSB抗体水平（P＜0.05、0.01、0.001），下调Chuk、Rela、AQP5 mRNA表达及下调核因子-κB（nuclear factor-κB，NF-κB）信号通路相关蛋白表达（P＜0.01、0.001），减轻颌下腺炎症反应，上调AQP5表达（P＜0.05、0.01、0.001），改善SS小鼠颌下腺分泌功能。结论 EECA对SS小鼠颌下腺功能的保护作用可能与抑制炎症反应、调节免疫稳态和促进AQP5表达有关。

Objective To study the effect and potential mechanism of ethanol extract of Cynanchum auriculatum (EECA) on submandibular gland dysfunction in Sjögren’s syndrome (SS) mice model. Methods LC-MS was used to identify the chemical components of EECA. C57BL/6 mice were immunized with submandibular gland autoantigen to establish an SS mouse model. Control group, model group, hydroxychloroquine sulfate (0.03 g/kg) group, EECA low-, medium-, and high-dose (0.4, 0.8, 1.6 g/kg) groups were set up, and drug intervention was given for 60 d. During the administration period, saliva secretion and water intake were recorded, and flow cytometry was used to detect the number of memory B cells and Th1/Th2 cell ratio in spleen of mice in each group; Hematoxylin-eosin (HE) staining was used to evaluate the pathological changes of submandibular gland tissues of mice in each group; The levels of cytokines [interleukin-1β (IL-1β), IL-17, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IL-4], immunoglobulins [immunoglobulin G (IgG), IgA, IgM], serum amyloid A (SSA) antibodies and anti SSB antibodies in serum were detected; Immunohistochemistry was used to detect the distribution and expression of aquaporin 5 (AQP5) in submandibular gland tissue; Western blotting was used to detect the protein expressions of AQP5, p65, p-p65, inhibitor of kappa B kinase α (IKKα), and p-IKKαin submandibular gland tissue; qRT-PCR was used to detect the mRNA expressions of Chuk, Rela and AQP5 in submandibular gland tissue. Results EECA could significantly increase the number of memory B cells (P < 0.01), regulate the Th1/Th2 cell ratio, and thus regulate the abnormal immune response in SS mice. EECA could significantly decrease the levels of IL-1β, IL-17, TNF-α, IFN-γ, IL-4, IgG, IgA, IgM, anti SSA and anti SSB antibodies in serum of SS mice (P < 0.05, 0.01, 0.001), down-regulate mRNA expressions of Chuk, Rela and AQP5 and nuclear factor-κB (NF-κB) signaling pathway related protein expressions (P < 0.01, 0.001), alleviate submandibular gland inflammation response, up-regulate AQP5 expression (P < 0.05, 0.01, 0.001), and improve submandibular gland secretion function in SS mice. Conclusion The protective effect of EECA on submandibular gland function in SS mice may be related to the inhibition of inflammatory response, regulation of immune homeostasis and promotion of AQP5 expression.

四川省科技厅应用基础研究项目（20YYJC0640）；成都中医药大学西南地区特色中药资源系统研究重点实验室开放研究基金（2020XSGG002）；四川固态酿造技术创新中心建设项目（2021ZYD0102）