Xu Haiyan, Wu Zhidan, Wang Pei, Gong Jili, Qiu Li, Gu Yueling, Zhan Li, Tian Fuyun, Gao Zhaobing
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.
Neurochem Res. 2025 Apr 19;50(3):147. doi: 10.1007/s11064-025-04396-w.
Epilepsy is a chronic neurological disorder characterized by recurrent seizures, approximately one-third of whom are resistant to current anti-seizure drugs (ASDs). Retigabine (RTG) is a potential treatment for treating drug-resistant epilepsy and KCNQ2-related developmental and epileptic encephalopathy (KCNQ2-DEE). However, its use is limited by side effects from high doses and long-term use. This study aims to evaluate the anticonvulsant efficacy of RTG in combination with (+)-borneol in mouse models of maximal electroshock seizure (MES) and 6-Hz (44-mA) seizure. The individual anti-seizure efficacy of RTG and (+)-borneol was evaluated in the MES and 6-Hz seizure models, then isobolographic analysis was conducted to assess their interactions. The plasma and brain concentrations of RTG were measured with and without (+)-borneol. Electrophysiological experiments using the patch-clamp technique investigated the interactions of (+)-borneol and RTG at the α1β3γ2L-GABAAR and KCNQ2 channels. Both RTG and (+)-borneol exhibited anticonvulsant activity in MES and 6-Hz seizure models. In the isobolographic analysis, the co-administration of RTG and (+)-borneol proved to be significantly more effective than predicted based on additive effects. The ED50mix was reduced by approximately 20 to 100-fold and 2 to 6-fold compared to the ED50add in the MES and 6-Hz models, respectively. The plasma and brain levels of RTG increased following co-administration with higher doses of (+)-borneol. Patch-clamp studies indicated that both RTG and (+)-borneol positively modulated α1β3γ2L-GABAAR currents and showed additive effects. However, (+)-borneol inhibited the KCNQ2 current at 100 µM and did not enhance RTG activation on KCNQ2 channels at this concentration. These results demonstrate that (+)-borneol enhances the antiseizure effects of RTG by both pharmacokinetic and pharmacodynamic interaction and this approach may be clinically effective for patients with intractable seizures or KCNQ2-DEE.
癫痫是一种慢性神经系统疾病，其特征为反复发作的癫痫，其中约三分之一对目前的抗癫痫药物（ASD）耐药。瑞替加滨（RTG）是治疗耐药性癫痫和KCNQ2相关发育性及癫痫性脑病（KCNQ2-DEE）的一种潜在疗法。然而，其使用受到高剂量和长期使用所产生副作用的限制。本研究旨在评估RTG与（+）-冰片联合用药在最大电休克惊厥（MES）和6赫兹（44毫安）惊厥小鼠模型中的抗惊厥疗效。在MES和6赫兹惊厥模型中评估了RTG和（+）-冰片各自的抗癫痫疗效，然后进行等效应线分析以评估它们之间的相互作用。测定了有无（+）-冰片情况下RTG的血浆和脑内浓度。使用膜片钳技术的电生理实验研究了（+）-冰片和RTG在α1β3γ2L-γ-氨基丁酸A型受体（GABAAR）和KCNQ2通道上的相互作用。RTG和（+）-冰片在MES和6赫兹惊厥模型中均表现出抗惊厥活性。在等效应线分析中，RTG与（+）-冰片联合给药被证明比基于相加效应所预测的显著更有效。与MES和6赫兹模型中的相加效应半数有效量（ED50add）相比，联合用药半数有效量（ED50mix）分别降低了约20至100倍和2至6倍。与较高剂量的（+）-冰片联合给药后，RTG的血浆和脑内水平升高。膜片钳研究表明，RTG和（+）-冰片均对α1β3γ2L-GABAAR电流产生正向调节作用并表现出相加效应。然而，（+）-冰片在100微摩尔浓度时抑制KCNQ2电流，且在此浓度下不增强RTG对KCNQ2通道的激活作用。这些结果表明，（+）-冰片通过药代动力学和药效学相互作用增强了RTG的抗癫痫作用，并且这种方法可能对难治性癫痫或KCNQ2-DEE患者具有临床疗效。
