A critical review of evidence for preclinical differences between rasagiline and selegiline

A neoteric annotation on the advances in combination therapy for Parkinson's disease: nanocarrier-based combination approach and future anticipation. Part I: exploring theoretical insights and pharmacological advances

INTRODUCTION

Parkinson's disease (PD) is a neurological condition defined by a substantial reduction in dopamine-containing cells in the substantia nigra. Levodopa (L-Dopa) is considered the gold standard in treatment. Recent research has clearly shown that resistance to existing therapies can develop. Moreover, the involvement of multiple pathways in the nigrostriatal dopaminergic neuronal loss suggests that modifying the treatment strategy could effectively reduce this degeneration.

AREAS COVERED

This review summarizes the key concerns with treating PD patients and the combinations, aimed at effectively managing PD. Part I focuses on the clinical diagnosis at every stage of the disease as well as the pharmacological treatment strategies that are applied throughout its course. It methodically elucidates the potency of multifactorial interventions in attenuating the disease trajectory, substantiating the rationale for co-administration of dual or multiple therapeutic agents. Significant emphasis is laid on evidence-based pharmacological combinations for PD management.

EXPERT OPINION

By utilizing multiple drugs in a combination fashion, this approach can leverage the additive or synergistic effects of these agents, amplify the spectrum of treatment, and curtail the risk of side effects by reducing the dose of each drug, demonstrating significantly greater efficacy.

Supported metals on porous solids as heterogeneous catalysts for the synthesis of propargylamines

This perspective summarizes recent developments in the synthesis of propargylamines using porous solids (zeolites, MOFs and carbon) as supports/catalysts.

Influence of energy deficiency on the subcellular processes of Substantia Nigra Pars Compacta cell for understanding Parkinsonian neurodegeneration

Parkinson's disease (PD) is the second most prominent neurodegenerative disease around the world. Although it is known that PD is caused by the loss of dopaminergic cells in substantia nigra pars compacta (SNc), the decisive cause of this inexorable cell loss is not clearly elucidated. We hypothesize that "Energy deficiency at a sub-cellular/cellular/systems level can be a common underlying cause for SNc cell loss in PD." Here, we propose a comprehensive computational model of SNc cell, which helps us to understand the pathophysiology of neurodegeneration at the subcellular level in PD. The aim of the study is to see how deficits in the supply of energy substrates (glucose and oxygen) lead to a deficit in adenosine triphosphate (ATP). The study also aims to show that deficits in ATP are the common factor underlying the molecular-level pathological changes, including alpha-synuclein aggregation, reactive oxygen species formation, calcium elevation, and dopamine dysfunction. The model suggests that hypoglycemia plays a more crucial role in leading to ATP deficits than hypoxia. We believe that the proposed model provides an integrated modeling framework to understand the neurodegenerative processes underlying PD.

Rasagiline, a suicide inhibitor of monoamine oxidases, binds reversibly to α-synuclein

Rasagiline (N-propargyl-1-R-aminoindan) and selegiline (1-deprenyl) are MAO-B inhibitors which are used in the treatment of Parkinson's disease. The binding of rasagiline, selegiline, and their metabolites including 1-aminoindan, 2-aminoindan, and methamphetamine to α-synuclein was investigated by nanopore analysis and isothermal titration calorimetry. Blockade current histograms of α-synuclein alone give a peak at -86 pA which is due to translocation of the protein through the pore. In the presence of rasagiline and R-1-aminoindan, this peak shifts to about -80 pA. In the presence of selegiline and R-methamphetamine, the number of events at -86 pA is reduced and there is a higher proportion of bumping events at about -25 pA which are due to a more compact conformation. Rasagiline can also bind to sites in both the N- and C-terminal regions of α-synuclein. The binding constants of rasagiline and selegiline were estimated by isothermal titration calorimetry to be about 5 × 10(5) and <10(4) M(-1), respectively. A model is presented in which both rasagiline and R-1-aminoindan bind to α-synuclein, forming a loop structure which is less likely to aggregate or form fibrils. In contrast, selegiline binds and forms a more compact structure similar to that formed by methamphetamine.

Rasagiline: a review of its use in the treatment of idiopathic Parkinson's disease

Rasagiline (Azilect(®)) is an oral, second-generation, selective, irreversible monoamine oxidase-B (MAO-B) inhibitor approved in the US for the treatment of Parkinson's disease. In randomized, controlled trials, oral rasagiline 1 mg once daily was superior to placebo in the symptomatic treatment of early Parkinson's disease, both as monotherapy or as an adjunct to dopamine agonists. Comparisons of early-start and delayed-start treatment suggested a disease-modifying effect for rasagiline, but the results were equivocal. Rasagiline 0.5 or 1 mg/day was also superior to placebo as adjunctive therapy to levodopa in Parkinson's disease patients with motor fluctuations. Rasagiline was generally well tolerated in clinical trials, displaying a placebo-like tolerability profile in several studies. Cost-utility studies predicted that rasagiline, either as monotherapy or adjunctive therapy, would be a cost-effective treatment option. Therefore, oral rasagiline is a valuable therapeutic option for use in all stages of Parkinson's disease.