Department of Pharmacology, College of Pharmacy, Ningxia Medical University, 1160 Shengli Street, Yinchuan, 750004, China.
Pharmacy Department of Yulin First Hospital, Shaanxi, China.
Cell Mol Neurobiol. 2018 Mar;38(2):529-540. doi: 10.1007/s10571-017-0501-5. Epub 2017 May 9.
Oxysophocarpine (OSC), an alkaloid isolated from Sophora flavescens Ait, has been traditionally used as a medicinal agent based on the observed pharmacological effects. In this study, the direct effect of OSC against neuronal injuries induced by oxygen and glucose deprivation (OGD) in neonatal rat primary-cultured hippocampal neurons and its mechanisms were investigated. Cultured hippocampal neurons, which were exposed to OGD for 2 h followed by a 24 h reoxygenation, were used as an in vitro model of ischemia and reperfusion. 2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were used to confirm neural damage and to further evaluate the protective effects of OSC. The concentration of intracellular-free calcium [Ca] and mitochondrial membrane potential (MMP) were measured to determine the intracellular mechanisms and to further estimate the degree of neuronal damage. Changes in expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, p-ERK1/2, p-JNK1/2, and p-p38 MAPK were also observed in the in vitro model. It was shown that OSC (0.8, 2, or 5 µmol/L) significantly attenuated the increased absorbance of MTT, and the release of LDH manifests the neuronal damage by the OGD/R. Meanwhile, the pretreatment of the neurons during the reoxygenation period with OSC significantly increased MMP; it also inhibited [Ca] the elevation in a dose-dependent manner. Furthermore, the pretreatment with OSC (0.8, 2, or 5 µmol/L) significantly down-regulated expressions of IL-1β, TNF-α, p-ERK1/2, p-JNK1/2, and p-p38 MAPK in neonatal rat primary-cultured hippocampal neurons induced by OGD/R injury. In conclusion, OSC displays a protective effect on OGD-injured hippocampal neurons by attenuating expression of inflammatory factors via down-regulated the MAPK signaling pathway.
氧化槐果碱 (OSC) 是从苦参中分离出来的一种生物碱，基于观察到的药理作用，它一直被传统用作药物。在这项研究中，研究了 OSC 对新生大鼠原代培养海马神经元缺氧和葡萄糖剥夺 (OGD) 诱导的神经元损伤的直接作用及其机制。用氧葡萄糖剥夺 2 小时，再复氧 24 小时的培养海马神经元作为缺血再灌注的体外模型。使用 2-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐 (MTT) 测定法和乳酸脱氢酶 (LDH) 测定法来确认神经损伤，并进一步评估 OSC 的保护作用。测量细胞内游离钙 [Ca] 和线粒体膜电位 (MMP) 的浓度以确定细胞内机制，并进一步估计神经元损伤的程度。还观察了 TNF-α（肿瘤坏死因子-α）、白细胞介素 (IL)-1β、p-ERK1/2、p-JNK1/2 和 p-p38 MAPK 在体外模型中的表达变化。结果表明，OSC（0.8、2 或 5µmol/L）可显著减轻 OGD/R 引起的 MTT 吸光度增加和 LDH 释放，表明神经元损伤。同时，OSC 在复氧期间对神经元的预处理可显著增加 MMP；它还以剂量依赖的方式抑制 [Ca] 的升高。此外，OSC（0.8、2 或 5µmol/L）预处理可显著下调 OGD/R 损伤新生大鼠原代培养海马神经元中 IL-1β、TNF-α、p-ERK1/2、p-JNK1/2 和 p-p38 MAPK 的表达。综上所述，OSC 通过下调 MAPK 信号通路，降低炎症因子的表达，对 OGD 损伤的海马神经元发挥保护作用。
