骨碎补总黄酮调控ER-p38 MAPK信号通路改善东莨菪碱模型小鼠学习记忆功能障碍机制研究

Total flavonoids of Drynariae Rhizoma regulates ER-p38 MAPK signaling pathway to improve scopolamine-induced learning and memory impairments in model mice

研究骨碎补总黄酮对东莨菪碱模型小鼠学习记忆障碍的改善作用及机制。该研究将90只4月龄昆明(KM)小鼠随机分成6组,模型组与空白组灌胃生理盐水,给药组分别灌胃骨碎补总黄酮、抗脑衰胶囊、盐酸多奈哌齐以及骨碎补总黄酮加雌激素受体(ER)阻断剂,采用腹腔注射东莨菪碱的方法建立学习记忆功能障碍模型。水迷宫检测小鼠学习和记忆能力,免疫组织化学法检测小鼠海马内雌激素受体β(ERβ)表达,Western blot法检测海马中ERβ、磷酸化p38(p-p38)的表达和凋亡系统中B淋巴细胞瘤-2(Bcl-2)、Bcl-2关联死亡启动子(Bad)、半胱天冬氨酸蛋白酶-3(caspase-3)的蛋白含量,试剂盒检测海马中丙二醛(MDA)、超氧化物歧化酶(SOD)、一氧化氮(NO)蛋白含量。结果显示,与空白组比较,模型组潜伏期显著延长,穿越平台次数及靶象限停留时间显著降低,小鼠海马区中ERβ、Bcl-2含量及SOD酶活性显著减少,p-p38/p38、Bad、caspase-3、MDA及NO含量显著增加。与模型组比较,骨碎补总黄酮组可增加海马ERβ和SOD的表达,神经元促进凋亡蛋白表达显著减少、抑制凋亡蛋白表达增加,降低p-p38/p38、MDA及NO表达。ER阻断剂组可逆转骨碎补总黄酮在上述指标中的作用。说明骨碎补总黄酮能够明显改善东莨菪碱所致小鼠学习记忆障碍,其机制可能是通过雌激素受体-p38丝裂原激活的蛋白激酶(ERp38 MAPK)信号通路调节东莨菪碱模型小鼠的神经凋亡系统和氧化应激来实现的。

This study intended to explore the effect and mechanism of total flavonoids of Drynariae Rhizoma in improving scopolamine-induced learning and memory impairments in model mice.Ninety four-month-old Kunming(KM)mice were randomly divided into six groups.The ones in the model group and blank group were treated with intragastric administration of normal saline,while those in the medication groups separately received the total flavonoids of Drynariae Rhizoma,Kangnaoshuai Capsules,donepezil,as well as total flavonoids of Rhizoma Drynariae plus estrogen receptor(ER)blocker by gavage.The mouse model of learning and memory impairments was established via intraperitoneal injection of scopolamine.Following the measurement of mouse learning and memory abilities in Morris water maze test,the hippocampal ERβexpression was detected by immunohistochemistry,and the expression levels of ERβand phosphorylated p38(p-p38)in the hippocampus and B-cell lymphoma 2(Bcl-2),Bcl-2-associated death promoter(Bad),and cysteinyl aspartate-specific protease-3(caspase-3)in the apoptotic system were assayed by Western blot.The contents of malondialdehyde(MDA),superoxide dismutase(SOD),and nitric oxide(NO)in the hippocampus were then determined using corresponding kits.Compared with the control group,the model group exhibited significantly prolonged incubation period,reduced frequency of crossing the platform,shortened residence time in the target quadrant,lowered ERβ,Bcl-2 and SOD activity in the hippocampus,and increased p-p38/p38,Bad,caspase-3,MDA,and NO.Compared with the model group,the total flavonoids of Rhizoma Drynariae increased the expression of ERβand SOD in the hippocampus,down-regulated the expression of neuronal pro-apoptotic proteins,up-regulated the expression of anti-apoptotic proteins,and reduced p-p38/p38,MDA,and NO.The effects of total flavonoids of Drynariae Rhizoma on the above indexes were reversed by ER blocker.It has been proved that the total flavonoids of Drynariae Rhizoma obviously alleviate scopolamine-induced learning and memory impairments in mice,which may be achieved by regulating the neuronal apoptotic system and oxidative stress via the ER-p38 mitogen-activated protein kinase(ER-p38 MAPK)signaling pathway.