Anticonvulsant effects of bis-1,4-dihydropyridines and the probable role of L-type calcium channels suggested by docking simulations

The influx/efflux of calcium (Ca²⁺) ions through channels in cellular membranes plays a pivotal role in many physiological and physiopathological processes. Among these are those involved in the physiopathology of epileptic seizures. Hence, the control of permeability of ions through these channels is considered a strategy for the development of anticonvulsant drugs. According to the previous reports, dihydropyridine derivatives have proven to be Ca²⁺ channel blockers and have anticonvulsive properties, presumably by means of their action on L-type Ca²⁺ channels (LCCs). The aim of the present study was to determine the anticonvulsant effects of four bis-1,4-dihydropyridines (bis-DHPs) in male CF1 mice (25-30 g bw) using two experimental models: maximal electroshock (MES, which induces convulsions with an alternating current of 60 Hz) and pentylenetetrazole administration (PTZ, 90 mg/kg administered i.p.). Additionally, the binding mode was explored with a docking study on a 3-D model of an LCC. The four bis-DHPs herein tested showed a protective effect in relation to the number of convulsions induced by MES, the recovery time after a convulsion, and the duration of the tonic phase. However, only bis-DHPs 01-03 reduced the duration of the clonic phase, and these compounds also produced a significant protective effect against the convulsions induced by PTZ administration. This effect may be related to the interaction of bis-DHPs with a cluster of aromatic residues (Tyr1152, Tyr1463, and Phe1159) involved in blocking calcium flow, as suggested by docking studies.