Promises of Novel Multi-target Neuroprotective and Neurorestorative Drugs for Parkinson's Disease

The cascade of neurotoxic events involved in neuronal degeneration suggests that it is naive to think mono-target drugs can induce disease modification by slowing the process of neurodegeneration in Parkinson's disease (PD). Employing the pharmacophore of rasagiline (N-propargyl-1-R-aminoindan), we have developed a series of novel multi-target neuroprotective drugs, including: (A) drugs [ladostigil, TV-3326 (N-propargyl-3R-aminoindan-5yl)-ethyl methylcarbamate)] with both cholinesterase-butyrylesterase (Ch-BuE) and brain-selective monamine oxidase-AB (MAO-AB) inhibitory activities and (B) iron chelator-radical scavenging drugs (M30) possessing brain-selective MAO-AB inhibitor activity and the neuroprotective-neurorescue propargylamine moiety of rasagiline. This was considered to be valid since brain MAO and iron increase in PD and aging, which could lead to oxidative stress-dependent neurodegeneration. The multi-target iron chelator, M30, has all the properties of ladostigil, but is not an acetylcholinesterase (CHE) inhibitor. However, M30 has both neuroprotective and neurorestorative activities for nigrostriatal dopamine neurons in post-lesion MPTP, lactacystin and 6-hydroxydopamine animal models of PD. The neurorestorative activity has been identified as being related to the ability of the drug to activate hypoxia-inducible factor (HIF) by inhibiting prolyl-4-hydroxylase. M30 regulates cell cycle arrest and induces the neurotrophins brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), erythropoietin (EPO), as well as glia-derived neurotrophic factor (GDNF). These unique multiple actions of M30 make it potentially useful as a disease modifying drug for the treatment of PD.