目的 探討白芍總苷對(duì)1-甲基-4-苯基-1,2,3,6-四氫吡啶（1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine，MPTP）致帕金森病小鼠的保護(hù)機(jī)制。方法 采用60%乙醇熱回流法提取白芍總苷，高效液相色譜法測(cè)定白芍總苷化學(xué)成分。60只小鼠隨機(jī)分為對(duì)照組、模型組、美多芭（100 mg/kg）組和白芍總苷（total glucosides of paeony，TGP）低、中、高劑量（0.75、1.50、3.00 g/kg）組，各給藥組ig給藥（20 mL/kg），對(duì)照組、模型組ig等體積雙蒸水（double-distilled water，ddH₂O），1次/d，連續(xù)15 d，自第8天起，對(duì)照組ip生理鹽水，其他各組小鼠每天ip MPTP（30 mg/kg）。第15天ip MPTP 1 h后，檢測(cè)小鼠的自主活動(dòng)、滾軸能力及懸掛能力；免疫組織化學(xué)法檢測(cè)各組小鼠黑質(zhì)多巴胺能神經(jīng)元的損傷情況，同時(shí)檢測(cè)腦組織中單胺氧化酶-B（monoamine oxidase-B，MAO-B）活性水平、神經(jīng)遞質(zhì)多巴胺（dopamine，DA）及其代謝產(chǎn)物3,4-二羥基苯乙酸（3,4-Dihydroxyphenylacetic acid，DOPAC）、高香草酸（homovanillic acid，HVA）；蛋白免疫印跡法檢測(cè)多巴胺轉(zhuǎn)運(yùn)體（dopamine Transporter，DAT）、酪氨酸羥化酶（tyrosine Hydroxylase，TH）、腦源性神經(jīng)營(yíng)養(yǎng)因子（brain-derived neurotrophic factor，BDNF）、磷酸化環(huán)磷腺苷反應(yīng)元件結(jié)合蛋白（phosphorylated cAMP-response element-binding protein，p-CREB）、環(huán)磷腺苷效應(yīng)元件結(jié)合蛋白（cAMP-response element binding protein，CREB）、B淋巴細(xì)胞瘤-2基因（B-cell lymphoma-2，Bcl-2）、Bcl-2相關(guān)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）蛋白表達(dá)水平。結(jié)果 MPTP誘導(dǎo)的帕金森病小鼠模型自發(fā)站立次數(shù)顯著減少、懸掛能力和滾軸能力顯著降低，顯著降低黑質(zhì)致密部TH陽(yáng)性神經(jīng)元數(shù)量；經(jīng)高劑量白芍總苷處理后能顯著增加小鼠的自發(fā)站立次數(shù)，提高滾軸能力（P＜0.05）；顯著增加TH陽(yáng)性神經(jīng)元數(shù)量（P＜0.01），提高小鼠腦內(nèi)的DA、HVA含量和DAT、TH、BDNF蛋白表達(dá)水平及p-CREB/CREB、Bcl-2/Bax的值（P＜0.01），抑制小鼠腦內(nèi)MAO-B、DOPAC、cleaved Caspase-3的表達(dá)（P＜0.01）。結(jié)論 白芍總苷高劑量組對(duì)MPTP誘導(dǎo)的小鼠損傷帕金森模型具有顯著的保護(hù)作用，其作用機(jī)制可能與白芍總苷能夠抑制MAO-B活性，提高DA及DAT、TH蛋白表達(dá)和激活CREB/BDNF及Bc1-2/Bax通路有關(guān)。

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

吉林省自然科學(xué)基金資助項(xiàng)目（20210101031JC）;吉林省自然科學(xué)基金資助項(xiàng)目（20240402045GH）