Neuroprotective function of R-(−)-1-(benzofuran-2-yl)-2-propylaminopentane, [ R-(−)-BPAP], against apoptosis induced by N-methyl( R)salsolinol, an endogenous dopaminergic neurotoxin, in human dopaminergic neuroblastoma SH-SY5Y cells

Abstract

R-(−)-1-(Benzofuran-2-yl)-2-propylaminopentane HCl [ R-(−)-BPAP] is one of “catecholaminergic and serotonergic enhancers“, which were proposed to improve symptoms through increase in impulse-evoked release of monoamine neurotransmitters for Parkinson's disease. It was reported that (−)-BPAP up-regulated the synthesis of neurotrophic factors in mouse astrocytes, suggesting the neuroprotective potency of (−)-BPAP. In this paper, the neuroprotective function of (−)-BPAP and the related compounds was examined against apoptosis induced by an endogenous neurotoxin, N-methyl( R)salsolinol [ NM( R)Sal], a possible pathogenic toxin in Parkinson's disease, in human dopaminergic neuroblastoma SH-SY5Y cells. The anti-apoptotic activity was confirmed with some of (−)-BPAP analogues, and the mechanism was found to be due to the direct stabilization of mitochondrial membrane potential and the induction of anti-apoptotic Bcl-2. The studies on structure-activity relationship demonstrated that the potency to stabilize the mitochondrial membrane potential depended on the absolute stereo-chemical structure of BPAP derivatives. The compounds with dextrorotation prevented the mitochondrial permeability transition, whereas those with levorotation did not. The presence of a propargyl or propyl group at the amino residue of R-(−)-1-(benzofuran-2-yl)-2-propylamine increased potency to stabilize the membrane potential and prevent apoptosis. R-FPFS-1169 and R-FPFS-1180 had more potent to induce Bcl-2 and prevent apoptosis than the corresponding S-enantiomers. These results are discussed with the possible application of BPAP derivatives as neuroprotective agents in Parkinson's disease and other neurodegenerative disorders.