Jiang Qian, Li Run-Ping, Tang Ying, Wang Ye-Qing, Liu Chong, Guo Mei-Li
Department of Pharmacognosy, College of Pharmacy, Second Military Medical University, Shanghai, China.
Department of Diving Medicine, Faculty of Naval Medicine, Second Military Medical University, Shanghai, China.
CNS Neurosci Ther. 2015 Dec;21(12):943-52. doi: 10.1111/cns.12470. Epub 2015 Oct 28.
This study was designed to examine the neuroprotective effects of bakkenolide-IIIa, a major novel compound extracted from the rhizome of P. trichinous.
Transient focal cerebral damage model in rats and oxygen-glucose deprivation (OGD) in cultured hippocampal neurons were performed. The amount of apoptotic neurons was determined using TUNEL assay. The expressions of Bcl-2, Bax, Akt, ERK1/2, IKKβ, IκBα were measured using Western blot. The nuclear translocation and activation of NF-κB was measured using a fluorescence microscope and electrophoretic mobility shift assay (EMSA).
Bakkenolide-IIIa (4, 8, 16 mg/kg; i.g.) was administered immediately after reperfusion could reduce the brain infarct volume, and the neurological deficit, as well as a high dose of bakkenolide-IIIa, increases the 72 h survival rate in cerebrally damaged rats. In vitro data demonstrated that bakkenolide-IIIa could increase cell viability and decrease the amount of apoptotic cells in cultured primary hippocampal neurons exposed to OGD. Bakkenolide-IIIa also dose-dependently increased the ratio of Bcl-2 to Bax. These results indicated that inhibition of apoptosis partly mediated the neuroprotection of bakkenolide-IIIa. Furthermore, bakkenolide-IIIa inhibited the phosphorylation of Akt, ERK1/2, IKKβ, IκBα, and p65 in cultured hippocampal neurons exposed to OGD. Bakkenolide-IIIa not only inhibited the nuclear translocation of NF-κB in cultured neurons exposed to OGD, but also inhibited the activation of NF-κB in peri-infarct area in cerebrally damaged rats.
Collectively, our findings indicated that bakkenolide-IIIa protects against cerebral damage by inhibiting AKT and ERK1/2 activation and inactivated NF-κB signaling.
本研究旨在探讨从毛山药根茎中提取的一种主要新型化合物——蜂斗菜内酯-IIIa的神经保护作用。
建立大鼠短暂局灶性脑损伤模型以及培养海马神经元的氧糖剥夺（OGD）模型。采用TUNEL法测定凋亡神经元数量。运用蛋白质免疫印迹法检测Bcl-2、Bax、Akt、ERK1/2、IKKβ、IκBα的表达。使用荧光显微镜和电泳迁移率变动分析（EMSA）测定NF-κB的核转位和活化情况。
再灌注后立即给予蜂斗菜内酯-IIIa（4、8、16mg/kg；腹腔注射）可减少脑梗死体积和神经功能缺损，且高剂量的蜂斗菜内酯-IIIa可提高脑损伤大鼠72小时生存率。体外实验数据表明，蜂斗菜内酯-IIIa可提高暴露于OGD的原代培养海马神经元的细胞活力并减少凋亡细胞数量。蜂斗菜内酯-IIIa还呈剂量依赖性增加Bcl-2与Bax的比值。这些结果表明，抑制凋亡部分介导了蜂斗菜内酯-IIIa的神经保护作用。此外，蜂斗菜内酯-IIIa抑制了暴露于OGD的培养海马神经元中Akt、ERK1/2、IKKβ、IκBα和p65的磷酸化。蜂斗菜内酯-IIIa不仅抑制了暴露于OGD的培养神经元中NF-κB的核转位，还抑制了脑损伤大鼠梗死周边区域NF-κB的活化。
总体而言，我们的研究结果表明，蜂斗菜内酯-IIIa通过抑制AKT和ERK1/2活化以及使NF-κB信号失活来保护大脑免受损伤。
