Parkinson's disease (PD) ranks second in the prevalence of neurodegenerative disorders after Alzheimer's disease among the elderly. The rapid increase in the number of PD patients urgently demands effective treatment .The natural product tetramethylpyrazine has been reported as both a free radical scavenger and anti-inflammatory agent. In this study, we designed a new tetramethylpyrazine derivative and tested it for neuroprotective effect in the experimental PD models. Pretreatment with TN-2 exhibited significant neuroprotective activity against 6-OHDA-induced PC12 cell apoptosis. Moreover, TN-2 could prevent 6-OHDA-induced dopaminergic (DA) neuron loss and behavior alternation in zebrafish. The subsequent mechanism study illustrated that TN-2 exhibit its neuroprotective effect via inhibiting neuroinflammation related pathways. TN-2 surpressed the over production of NO and up-regulation of iNOS through NF-kB modulation. Additionally, PKC/ PI3K/Akt pathway was also involved in the protective function of TN-2. The neuroprotective activity of TN-2 was further confirmed in the MPP+-induced SH-SY5Y human nuroblastoma cell model and MPTP-induced mouse model. TN-2 inhibited MPP+-induced apoptosis in SH-SY5Y cells by suppressing over-production of reactive oxygen species, blocking mitochondrial cytochrome c release, reducing caspase 3 cleavage and maintaining Bax/Bcl-2 ratio. Treatment with TN-2 also markedly protected loss of tyrosine hydroxylase (TH)-positive neurons in the MPTP-induced mouse PD model. TN-2 elevated the SOD and GSSH activity and avoided MDA-inducd damage in the substantia nigra par compacta (SNpc) in MPTP-lesioned mice brain. In summary, the present study provided solid scientific evidences from various in vitro and in vivo models to demonstrate the neuroprotective activity of TN-2. The results suggested that TN-2 exerted its effects via different pathways. It is indicated that TN-2 is a promising agent for the prevention and therapy of PD.

探討天然產物川芎嗪的衍生物TN-2在帕金森病實驗模型上的神經保護作用 及其機制。 帕金森病作為第二大神經退行性疾病，近年來蔓延迅速。目前的治療手段以 緩解症狀為主，並無有效防治藥物。天然產物川芎嗪經研究發現有抗炎與抗自由 基效果。本研究在川芎嗪結構基礎上設計合成了新的化合物TN-2。我們發現新化 合物TN-2在帕金森病實驗模型生表現出良好的神經保護效果。 首先，在6-羥基 多巴胺誘導的PC-12細胞損傷模型上，TN-2表現出良好的保護作用。進一步機理 研究顯示TN-2在PC12細胞上通過阻斷炎症相關的inos和NF-kB通路以及上調細胞 生存相關的PKC/Pi3k/Akt通路來實現保護效果。同時，在6-羥基多巴胺誘導的斑 馬魚多巴胺能神經元損傷模型中，TN-2同樣表現出良好的保護效果。在1-甲基-4- 苯基-1,2,3,6四氫吡啶（MPTP）誘導的SH-SY5Y細胞模型上，TN-2 通過清除自由 基，保護線粒體膜電位，阻斷線粒體凋亡通路等保護細胞。在MPTP誘導的小鼠 帕金森模型中， TN-2有效的抑制了MPTP對小鼠黑質紋狀體多巴胺能神經元的損 傷。 綜上，TN-2 可能成為一個有潛力的多靶點抗帕金森藥物。 關鍵字:川芎嗪；神經保護；神經退行性病；帕金森症；PC12細胞；SH-SY5Y细 胞；斑馬魚；6-羥基多巴胺；MPTP；一氧化氮；誘導型一氧化氮合酶；NF-kB； Akt；自由基；线粒体；凋亡