目的 观察荆芥Schizonepeta tenuifolia挥发油对慢性温和不可预知应激（chronic unpredictable mild stress，CUMS）模型小鼠抑郁样行为的干预作用，探究其调控NOD样受体热蛋白结构域相关蛋白3（NOD-like receptor pyrin domain containing 3，NLRP3）炎症小体/细胞焦亡从而抑制神经炎症的作用机制。方法 雄性ICR小鼠制备CUMS抑郁样模型，依据糖水偏好率将造模成功的小鼠随机分为模型组、氟西汀（10 mg/kg）组和荆芥挥发油高、低剂量（100、50 mg/kg）组，同时设置对照组。给予药物干预5周后，进行小鼠糖水偏好实验、强迫游泳实验、悬尾实验与飞溅实验。行为学测试结束后，取血并分离血清，取海马组织。ELISA法测定血清中白细胞介素-1β（interleukin-1β，IL-1β）和肿瘤坏死因子-α（tumor necrosis factor-α，TNF-α）水平；尼氏染色法检测海马CA3区神经元尼氏小体平均吸光度值；免疫荧光法检测海马CA3区NLRP3、活化的半胱氨酸天冬氨酸蛋白酶-1（cleaved cystein-asparate protease-1，cleaved Caspase-1）、IL-1β及小胶质细胞离子钙结合适配器分子-1（ionized calcium binding adapter molecule-1，Iba-1）表达；Western blotting检测海马组织NLRP3炎症小体及焦亡通路相关蛋白表达。结果 与模型组比较，荆芥挥发油能明显提高小鼠糖水偏好率（P<0.01），显著缩短小鼠强迫游泳与悬尾实验中的不动时间（P<0.01、0.001），明显延长飞溅实验中的小鼠梳洗时间（P<0.05），表现出抗抑郁样行为作用。荆芥挥发油显著降低小鼠血清中IL-1β水平（P<0.05、0.01），增加海马CA3区神经元尼氏小体数目（P<0.05、0.01），减弱海马CA3区cleaved Caspase-1、IL-1β及Iba-1的平均荧光强度（P<0.05、0.01、0.001），并显著下调海马组织NLRP3、凋亡相关斑点样蛋白（apoptosis-associated speck-like protein containing a CARD，ASC）、Caspase-1、cleaved Caspase-1、IL-1β、pro IL-1β、gasdermin-D（GSDMD）、N-GSDMD及Iba-1的蛋白表达（P<0.05、0.01、0.001）。结论 荆芥挥发油能改善CUMS模型小鼠的抑郁样行为，具有抗抑郁作用，其作用机制与抑制NLRP3炎症小体激活及细胞焦亡、抑制小胶质细胞活化，从而减轻神经炎症反应与神经元损伤有关。

Objective To observe the intervention effect of essential oil from Schizonepeta tenuifolia on depression-like behavior in chronic unpredictable mild stress (CUMS) model mice, and investigate its mechanism of regulating NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome and pyroptosis signaling pathway to inhibit neuroinflammation. Methods CUMS depression-like model was established in male ICR mice. According to the preference rate of sugar water, the successful modeling mice were randomly divided into model group, fluoxetine (10 mg/kg) group and essential oil from S. tenuifolia high-, low-dose (100, 50 mg/kg) groups, and the control group was set at the same time. After five weeks of drug intervention, the sugar water preference test, forced swimming test, tail suspension test and splash test were carried out in mice. After the behavioral test, blood was taken and serum was separated, and hippocampus tissue was taken. Levels of interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) in serum were measured by ELISA. Nissl staining was used to detect the average optical density of Nissl body in hippocampal CA3 neurons. The expressions of NLRP3, cleaved cystein-asparate protease-1 (cleaved Caspase-1), IL-1β and ionized calcium binding adapter molecule-1 (Iba-1) in hippocampus CA3 were detected by immunofluorescence. Western blotting was used to detect the expressions of NLRP3 inflammasome and pyroptosis signaling pathway related proteins in hippocampus. Results Compared with model group, essential oil from S. tenuifolia significantly improved the preference rate of sugar water in mice (P < 0.01), significantly shortened the immobility time in forced swimming and tail suspension tests (P < 0.01, 0.001), and significantly prolonged the grooming time in splash tests (P < 0.05), showing the antidepressant-like behavior. The essential oil from S. tenuifolia significantly decreased the level of IL-1β in serum of mice (P < 0.05, 0.01), increased the number of Nissl body in hippocampal CA3 area (P < 0.05, 0.01), weakened the average fluorescence intensity of cleaved Caspase-1, IL-1β and Iba-1 in hippocampal CA3 area (P < 0.05, 0.01, 0.001), downregulated NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, cleaved Caspase-1, IL-1β, pro IL-1β, gasdermin-D (GSDMD), N-GSDMD and Iba-1 protein expressions in hippocampus (P < 0.05, 0.01, 0.001). Conclusion The essential oil from S. tenuifolia can improve the depression-like behavior of CUMS model mice, and has antidepressant effect. Its mechanism is related to inhibiting the activation of inflammasome of NLRP3 and pyroptosis, and inhibiting the activation of microglia, thus reducing the neuroinflammatory reaction and neuronal injury.

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西南特色中药资源国家重点实验室开放研究基金项目（2020XSGG002）；国家自然科学基金资助项目（82074094）