Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
Department of Pharmacology, Manipal College of Pharmaceutical Sciences, MAHE, Manipal, Karnataka, 576104, India.
Inflammopharmacology. 2021 Feb;29(1):137-151. doi: 10.1007/s10787-020-00782-8. Epub 2021 Jan 1.
The initial precipitating injury such as SE progresses to chronic epilepsy through multiple epileptogenic processes. Early epileptogenic events are generally characterized by neuroinflammation, neurodegeneration and abnormal neurogenesis in the hippocampus. Metformin has exhibited anti-inflammatory and neuroprotective properties in numerous studies. The current study attempts to investigate the effect of metformin on seizure-induced inflammation and neuronal degeneration, and the involvement of the mTOR pathway. Status epilepticus (SE) was induced in male Wistar rats with systemic administration of Lithium (127 mg/kg) and Pilocarpine (30 mg/kg). In test rats, Metformin 100 mg/kg or 200 mg/kg was administered orally for 7 days, followed by SE induction. Results indicate that metformin did not alter the SE profile significantly which was evident by the behavioural scoring and electroencephalogram (EEG) recordings. However, metformin 200 mg/kg attenuated the SE-induced glial activation (p < 0.01), up regulated mRNA levels of proinflammatory cytokines (p < 0.001) and chemokines (p < 0.001) and enhanced BBB permeability (p < 0.05). In addition, metformin ameliorated the insult-induced region-specific neuronal damage (p < 0.01) and restored the hippocampal neuronal density. Metformin significantly inhibited phosphorylated S6 ribosomal protein (phospho-S6rp) (p < 0.05), thus demonstrating that the beneficial effects might be partly mediated by the mTOR pathway. The study thus reiterates that mTOR signalling is one of the mechanisms involved in inflammation and neurodegeneration in early epileptogenesis following SE.
最初的诱发损伤,如 SE,通过多种致痫过程进展为慢性癫痫。早期致痫事件通常以海马区的神经炎症、神经退行性变和异常神经发生为特征。二甲双胍在许多研究中表现出抗炎和神经保护作用。本研究试图探讨二甲双胍对癫痫诱导的炎症和神经元变性的作用,以及 mTOR 通路的参与。通过全身给予锂(127mg/kg)和毛果芸香碱(30mg/kg)在雄性 Wistar 大鼠中诱导癫痫持续状态(SE)。在测试大鼠中,给予二甲双胍 100mg/kg 或 200mg/kg 口服 7 天,然后诱导 SE。结果表明,二甲双胍并未显著改变 SE 谱,这从行为评分和脑电图(EEG)记录中可以明显看出。然而,二甲双胍 200mg/kg 减轻了 SE 诱导的神经胶质激活(p<0.01),上调了促炎细胞因子(p<0.001)和趋化因子(p<0.001)的 mRNA 水平,并增强了 BBB 通透性(p<0.05)。此外,二甲双胍改善了损伤诱导的特定区域神经元损伤(p<0.01)并恢复了海马神经元密度。二甲双胍显著抑制磷酸化 S6 核糖体蛋白(磷酸化 S6rp)(p<0.05),表明其有益作用可能部分通过 mTOR 通路介导。因此,该研究再次强调,mTOR 信号通路是 SE 后早期癫痫发生中炎症和神经退行性变的机制之一。