目的 探讨白芍总苷对1-甲基-4-苯基-1,2,3,6-四氢吡啶（1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine，MPTP）致帕金森病小鼠的保护机制。方法 采用60%乙醇热回流法提取白芍总苷，高效液相色谱法测定白芍总苷化学成分。60只小鼠随机分为对照组、模型组、美多芭（100 mg/kg）组和白芍总苷（total glucosides of paeony，TGP）低、中、高剂量（0.75、1.50、3.00 g/kg）组，各给药组ig给药（20 mL/kg），对照组、模型组ig等体积双蒸水（double-distilled water，ddH₂O），1次/d，连续15 d，自第8天起，对照组ip生理盐水，其他各组小鼠每天ip MPTP（30 mg/kg）。第15天ip MPTP 1 h后，检测小鼠的自主活动、滚轴能力及悬挂能力；免疫组织化学法检测各组小鼠黑质多巴胺能神经元的损伤情况，同时检测脑组织中单胺氧化酶-B（monoamine oxidase-B，MAO-B）活性水平、神经递质多巴胺（dopamine，DA）及其代谢产物3,4-二羟基苯乙酸（3,4-Dihydroxyphenylacetic acid，DOPAC）、高香草酸（homovanillic acid，HVA）；蛋白免疫印迹法检测多巴胺转运体（dopamine Transporter，DAT）、酪氨酸羟化酶（tyrosine Hydroxylase，TH）、脑源性神经营养因子（brain-derived neurotrophic factor，BDNF）、磷酸化环磷腺苷反应元件结合蛋白（phosphorylated cAMP-response element-binding protein，p-CREB）、环磷腺苷效应元件结合蛋白（cAMP-response element binding protein，CREB）、B淋巴细胞瘤-2基因（B-cell lymphoma-2，Bcl-2）、Bcl-2相关X蛋白（Bcl-2 associated X Protein，Bax）、裂解型半胱氨酸天冬氨酸蛋白酶-3（cleaved cystein-asparate protease-3，cleaved Caspase-3）蛋白表达水平。结果 MPTP诱导的帕金森病小鼠模型自发站立次数显著减少、悬挂能力和滚轴能力显著降低，显著降低黑质致密部TH阳性神经元数量；经高剂量白芍总苷处理后能显著增加小鼠的自发站立次数，提高滚轴能力（P＜0.05）；显著增加TH阳性神经元数量（P＜0.01），提高小鼠脑内的DA、HVA含量和DAT、TH、BDNF蛋白表达水平及p-CREB/CREB、Bcl-2/Bax的值（P＜0.01），抑制小鼠脑内MAO-B、DOPAC、cleaved Caspase-3的表达（P＜0.01）。结论 白芍总苷高剂量组对MPTP诱导的小鼠损伤帕金森模型具有显著的保护作用，其作用机制可能与白芍总苷能够抑制MAO-B活性，提高DA及DAT、TH蛋白表达和激活CREB/BDNF及Bc1-2/Bax通路有关。

Objective To explore the protective mechanism of total glucosides in Paeoniae Radix Alba (TGP) against MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine)in mice with Parkinson's disease. Methods The TGP was extracted by 60% ethanol reflux method, and the chemical constituents of TGP were determined by high-performance liquid chromatography (HPLC). Sixty mice were randomly divided into control group, model group, madopar (100 mg/kg) group, and low-, medium-, and high-dose (0.75, 1.50, 3.00 g/kg) TGP groups. Each treatment group received intragastric (ig) administration (20 mL/kg), while the control and model groups received an equivalent volume of double-distilled water (ddH₂O) via ig administration, once daily for 15 consecutive days. From the 8th day onward, the control group was intraperitoneally (ip) injected with normal saline, while the other groups received MPTP (30 mg/kg·d⁻¹) via ip injection. On the 15th day, one hour after the final MPTP injection, spontaneous activity, rotarod performance, and hanging ability were assessed. Immunohistochemistry was used to evaluate dopaminergic neuron damage in the substantia nigra. In addition, monoamine oxidase-B (MAO-B) activity, dopamine (DA), and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), were measured in brain tissue. Western blotting was employed to determine the protein expression levels of dopamine transporter (DAT), tyrosine hydroxylase (TH), brain-derived neurotrophic factor (BDNF), phosphorylated cAMP-response element-binding protein (p-CREB), CREB, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), and Cleaved cystein-asparate protease-3 (Cleaved Caspase-3). Results MPTP-induced Parkinson’s disease model mice exhibited a significant reduction in the number of spontaneous standing events, as well as a marked decline in hanging ability and rotarod performance. Furthermore, a significant decrease in the number of TH-positive neurons in the substantia nigra pars compacta was observed. High-dose TGP treatment significantly increased the number of spontaneous standing events and improved rotarod performance (P < 0.05). Additionally, TGP administration markedly increased the number of TH-positive neurons (P < 0.01) and elevated DA and HVA levels in the brain. TGP treatment also upregulated the expression levels of DAT, TH, and BDNF proteins and increased p-CREB/CREB and Bcl-2/Bax ratios (P < 0.01). Conversely, it significantly inhibited the expression of MAO-B, DOPAC, and cleaved caspase-3 in the brain (P < 0.01). Conclusion High-dose TGP exerts significant neuroprotective effects in MPTP-induced Parkinson’s disease model mice. The underlying mechanism may be associated with the inhibition of MAO-B activity, the elevation of DA levels, the upregulation of DAT and TH protein expression, and the activation of the CREB/BDNF and Bcl-2/Bax signaling pathways.

R285.5

吉林省自然科学基金资助项目（20210101031JC）;吉林省自然科学基金资助项目（20240402045GH）