Neuroprotective effects of novel cholinesterase inhibitors derived from rasagiline as potential anti-Alzheimer drugs

TV3326, (N-propargyl-(3R)-aminoindan-5-yl-ethyl,methyl carbamate) was prepared in order to combine the neuroprotective effects of rasagiline, a selective inhibitor of monoamine oxidase (MAO)-B with the cholinesterase (ChE) inhibitory activity of rivastigmine as a potential treatment for Alzheimer's disease. The study reported here examined the neuropotective effects of TV3326 against various insults in vitro and in vivo. TV3326 caused a dose related (10-500 μM) reduction in death induced in NGF differentiated rat pheochromocytoma (PC12) cells by 3-4 hour exposure to oxygen-glucose deprivation. A single sc injection of TV3326 given five minutes after closed head injury in mice significantly reduced the cerebral edema, and accelerated the recovery of motor function and spatial memory several days later. Unilateral icy injection of streptozotocin (STZ) 1.5 mg in rats, caused specific damage to myelinated neurones in the fornix and corpus callosum accompanied by microgliosis. Three bilateral injections of STZ, 0.25 mg each, caused more widespread damage, and a marked impairment in spatial memory. Chronic oral treatment with TV3326 (75 μmols/kg) reduced the neuronal damage and microgliosis and almost completely prevented the memory impairment. The neuroprotective effect in PC12 cells may be due to a combination of ChE inhibition and antiapoptotic activity. The latter does not result from ChE inhibition. It is associated with the presence of the propargyl group, since it occurs with other propargylamines that do not inhibit MAO, but not with drugs that inhibit only ChE.