JM-20, a novel benzodiazepine–dihydropyridine hybrid molecule, protects mitochondria and prevents ischemic insult-mediated neural cell death in vitro

Abstract

The ischemic stroke cascade is composed of several pathophysiological events, providing multiple targets for pharmacological intervention. JM-20 (3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-4,11-dihydro-1H-pyrido[2,3-b][1,5]benzodiazepine) is a novel hybrid molecule, in which a benzodiazepine portion is covalently linked to a dihydropyridine ring, forming a new chemical entity with potential multisite neuroprotective activity. In the present study, JM-20 prevented PC-12 cell death induced either by glutamate, hydrogen peroxide or KCN-mediated chemical hypoxia. This molecule also protected cerebellar granule neurons from glutamate or glutamate plus pentylenetetrazole-induced damage at very low micromolar concentrations. In rat liver mitochondria, JM-20, at low micromolar concentrations, prevented the Ca2+-induced mitochondrial permeability transition, as assessed by mitochondrial swelling, membrane potential dissipation and organelle release of the pro-apoptotic protein cytochrome c. JM-20 also inhibited the mitochondrial hydrolytic activity of F1F0-ATP synthase and Ca2+ influx. Therefore, JM-20 may be a multi-target neuroprotective agent, promoting reductions in neuronal excitotoxic injury and the protection of the mitochondria from Ca2+-induced impairment as well as the preservation of cellular energy balance.