Yuan Jun-Hui, Pan Feng, Chen Jie, Chen Cai-Er, Xie Deng-Pan, Jiang Xing-Zhu, Guo Su-Juan, Zhou Jun
Department of Neonatology, Wenling Maternal and Child Health Hospital, Wenling, Zhejiang, China.
Taizhou University Medical School, Taizhou, Zhejiang, China.
J Pharm Pharmacol. 2017 Jul;69(7):896-906. doi: 10.1111/jphp.12681. Epub 2017 May 2.
This study was designed to assess the effects of plumbagin on isoflurane-induced neurotoxicity.
Neonatal Sprague Dawley rat pups were treated with plumbagin (50, 100 or 150 mg/kg body weight, orally) from postnatal day 2. The pups on postnatal day 7 were subjected to isoflurane (0.75%) exposure for 6 h. Neuronal apoptosis in the hippocampal tissues was detected by TUNEL assay and FluroJade B staining following isoflurane exposure. Protein expressions were analysed by immunoblotting. RT-PCR was performed to assess mRNA levels of brain-derived neurotrophic factor (BDNF) and TrkB.
We observed reduced apoptosis in hippocampal CA1, CA3 and dentate gyrus regions along with severely reduced pro-apoptotic factors (Bad, Bax and cleaved caspase-3) expression and raised levels of Bcl-2, Bcl-xL, survivin, xIAP and cIAPs (cell survival proteins) in plumbagin supplemented rats. Decrease in the levels of JNK, phospho-JNK, c-Jun and phospho-c-Jun with enhanced ERK1/2 levels was observed on plumbagin pretreatment. Down-regulated PI3K/Akt signalling following isoflurane was activated by plumbagin as evidenced by raised PI3K/Akt pathway proteins - mTORc1, Akt, phospho-Akt, GSK-3β, phospho-GSK-3β, PTEN and NF-κBp65 in the hippocampal tissues as detected by Western blotting. The mRNA levels were enhanced on plumbagin supplementation.
Plumbagin exerted its neuroprotective effects by effectively suppressing isoflurane-induced neuronal apoptosis via regulating BDNF-TrkB-PI3/Akt and ERK/JNK signalling.
本研究旨在评估白花丹醌对异氟烷诱导的神经毒性的影响。
从出生后第2天起，对新生的斯普拉格-道利大鼠幼崽口服白花丹醌（50、100或150毫克/千克体重）。出生后第7天的幼崽接受6小时的异氟烷（0.75%）暴露。异氟烷暴露后，通过TUNEL法和荧光金B染色检测海马组织中的神经元凋亡。通过免疫印迹分析蛋白质表达。进行RT-PCR以评估脑源性神经营养因子（BDNF）和TrkB的mRNA水平。
我们观察到，在补充白花丹醌的大鼠中，海马CA1、CA3和齿状回区域的凋亡减少，同时促凋亡因子（Bad、Bax和裂解的半胱天冬酶-3）的表达严重降低，而细胞存活蛋白Bcl-2、Bcl-xL、survivin、xIAP和cIAPs的水平升高。白花丹醌预处理后，观察到JNK、磷酸化JNK、c-Jun和磷酸化c-Jun水平降低，ERK1/2水平升高。如通过蛋白质印迹法检测到的，海马组织中PI3K/Akt途径蛋白——mTORc1、Akt、磷酸化Akt、GSK-3β、磷酸化GSK-3β、PTEN和NF-κBp65升高，证明白花丹醌激活了异氟烷后下调的PI3K/Akt信号传导。补充白花丹醌后，mRNA水平升高。
白花丹醌通过调节BDNF-TrkB-PI3/Akt和ERK/JNK信号传导，有效抑制异氟烷诱导的神经元凋亡，从而发挥其神经保护作用。
