Rasagiline in Parkinson's disease: A review based on meta-analysis of clinical data

Ser9p-GSK3β Modulation Contributes to the Protective Effects of Vitamin C in Neuroinflammation

BACKGROUND

The prolonged activation of microglia and excessive production of pro-inflammatory cytokines can lead to chronic neuroinflammation, which is an important pathological feature of Parkinson's disease (PD). We have previously reported the protective effect of Vitamin C (Vit C) on a mouse model of PD. However, its effect on microglial functions in neuroinflammation remains to be clarified. Glycogen synthase kinase 3β (GSK3β) is a serine/threonine kinase having a role in driving inflammatory responses, making GSK3β inhibitors a promising target for anti-inflammatory research.

METHODS

In this study, we investigated the possible involvement of GSK3β in Vit C neuroprotective effects by using a well-known 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of PD and a cellular model of neuroinflammation, represented by Lipopolysaccharide (LPS)-activated BV-2 microglial cells.

RESULTS

We demonstrated the ability of Vit C to decrease the expression of different mediators involved in the inflammatory responses, such as TLR4, p-IKBα, and the phosphorylated forms of p38 and AKT. In addition, we demonstrated for the first time that Vit C promotes the GSK3β inhibition by stimulating its phosphorylation at Ser9.

CONCLUSION

This study evidenced that Vit C exerts an anti-inflammatory function in microglia, promoting the upregulation of the M2 phenotype through the activation of the Wnt/β-catenin signaling pathway.

A Systematic Review and Meta-Analysis of the Efficacy and Safety of Rasagiline or Pramipexole in the Treatment of Early Parkinson's Disease

Background

Rasagiline or pramipexole monotherapy has been suggested for the management of early Parkinson's disease (PD). The aim of this research was to systematically review the clinical efficacy and safety of rasagiline or pramipexole in early PD (defined as disease duration ≤5 years and Hoehn and Yahr stage of ≤3).

Methods

Randomized controlled trials (RCTs) of rasagiline or pramipexole for early PD published up to September 2021 were retrieved. Outcomes of interest included changes in the Unified Parkinson's Disease Rating Scale (UPDRS) Parts II and III and the incidence of adverse events. Standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (CI) were calculated, and heterogeneity was measured with the I2 test.

Results

Nine rasagiline and eleven pramipexole RCTs were included. One post hoc analysis of one rasagiline study was included. Five studies for each drug were included in meta-analyses of the UPDRS scores. The rasagiline meta-analysis focused on patients receiving 1 mg/day. Rasagiline and pramipexole significantly improved UPDRS Part II and III scores when compared to placebo. Significant heterogeneity among the studies was present (I2 > 70%). Neither rasagiline nor pramipexole increased the relative risk for any adverse events, serious adverse events, or adverse events leading to withdrawal when compared with placebo.

Conclusion

Applying a Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach to summarize the evidence, we found moderate confidence in the body of evidence for the efficacy of rasagiline or pramipexole in early PD, suggesting further well-designed, multicenter comparative RCTs remain needed.

Liposome-Derived Nanosystems for the Treatment of Behavioral and Neurodegenerative Diseases: The Promise of Niosomes, Transfersomes, and Ethosomes for Increased Brain Drug Bioavailability

Psychiatric and neurodegenerative disorders are amongst the most prevalent and debilitating diseases, but current treatments either have low success rates, greatly due to the low permeability of the blood-brain barrier, and/or are connected to severe side effects. Hence, new strategies are extremely important, and here is where liposome-derived nanosystems come in. Niosomes, transfersomes, and ethosomes are nanometric vesicular structures that allow drug encapsulation, protecting them from degradation, and increasing their solubility, permeability, brain targeting, and bioavailability. This review highlighted the great potential of these nanosystems for the treatment of Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, anxiety, and depression. Studies regarding the encapsulation of synthetic and natural-derived molecules in these systems, for intravenous, oral, transdermal, or intranasal administration, have led to an increased brain bioavailability when compared to conventional pharmaceutical forms. Moreover, the developed formulations proved to have neuroprotective, anti-inflammatory, and antioxidant effects, including brain neurotransmitter level restoration and brain oxidative status improvement, and improved locomotor activity or enhancement of recognition and working memories in animal models. Hence, albeit being relatively new technologies, niosomes, transfersomes, and ethosomes have already proven to increase the brain bioavailability of psychoactive drugs, leading to increased effectiveness and decreased side effects, showing promise as future therapeutics.

Safety and Effectiveness of Rasagiline in Chinese Patients with Parkinson's Disease: A Prospective, Multicenter, Non-interventional Post-marketing Study

INTRODUCTION

Rasagiline is indicated for treating idiopathic Parkinson's disease (PD) as monotherapy and adjunct therapy to levodopa in patients.

OBJECTIVES

To assess the post-marketing safety and tolerability of rasagiline in Chinese PD patients, as well as its effectiveness in improving motor symptoms.

METHODS

This prospective, non-interventional, multicenter, cohort study included PD patients administered rasagiline monotherapy or adjunct therapy to levodopa. The primary outcome was the incidence of adverse drug reactions (ADRs) according to MedDRA^® (version 22.0), and the secondary outcomes were the Parkinson's Disease Unified Rating Scale (UPDRS) part III, Clinical Global Impression-Severity (CGI-S), and Clinical Global Impression-Global-Improvement (CGI-I), assessed at Weeks 4, 12, and 24.

RESULTS

In total, 734 patients, 95 in the monotherapy subgroup and 639 in the adjunct therapy subgroup, were included in the safety population. The incidence rates of all ADRs were comparable between the monotherapy (15.8%) and adjunct therapy (13.6%) subgroups. The most common ADRs by system organ class were nervous system disorders (5.6%), gastrointestinal disorders (3.3%), psychiatric disorders (1.8%), vascular disorders (1.2%), and general disorders and administration site conditions (1.1%). Five (0.7%) participants experienced 5 serious ADRs. Improvements in UPDRS part III, CGI-S and CGI-I at Weeks 4, 12 and 24 from baseline were observed.

CONCLUSIONS

Safety data in this study indicated no extra safety concerns. Rasagiline is generally safe and well tolerated in Chinese PD patients. The safety profile and tolerability were in line with the established safety profile. Moreover, rasagiline reduced the severity of PD motor symptoms, confirming findings by previous clinical trials.

Neuroprotective Effects of Some Nutraceuticals against Manganese-Induced Parkinson's Disease in Rats: Possible Modulatory Effects on TLR4/NLRP3/NF-κB, GSK-3β, Nrf2/HO-1, and Apoptotic Pathways

Parkinson's disease (PD) is a progressive neurodegenerative disorder affecting the substantia nigra where functions controlling body movement take place. Manganese (Mn) overexposure is linked to a neurologic syndrome resembling PD. Sesamol, thymol, wheat grass (WG), and coenzyme Q10 (CoQ10) are potent antioxidants, anti-inflammatory, and anti-apoptotic nutraceuticals. We investigated the potential protective effects of these nutraceuticals alone or in combinations against MnCl₂-induced PD in rats. Seven groups of adult male Sprague Dawley rats were categorized as follows: group (I) was the control, while groups 2-7 received MnCl₂ either alone (Group II) or in conjunction with oral doses of sesamol (Group III), thymol (Group IV), CoQ10 (Group V), WG (Group VI), or their combination (Group VII). All rats were subjected to four behavioral tests (open-field, swimming, Y-maze, and catalepsy tests). Biochemical changes in brain levels of monoamines, ACHE, BDNF, GSK-3β, GABA/glutamate, as well as oxidative stress, and apoptotic and neuroinflammatory biomarkers were evaluated, together with histopathological examinations of different brain regions. Mn increased catalepsy scores, while decreasing neuromuscular co-ordination, and locomotor and exploratory activity. It also impaired vigilance, spatial memory, and decision making. Most behavioral impairments induced by Mn were improved by sesamol, thymol, WG, or CoQ10, with prominent effect by sesamol and thymol. Notably, the combination group showed more pronounced improvements, which were confirmed by biochemical, molecular, as well as histopathological findings. Sesamol or thymol showed better protection against neuronal degeneration and some behavioral impairments induced by Mn than WG or CoQ10, partly via interplay between Nrf2/HO-1, TLR4/NLRP3/NF-κB, GSK-3β and Bax/Bcl2 pathways.

Overall Efficacy and Safety of Safinamide in Parkinson's Disease: A Systematic Review and a Meta-analysis

BACKGROUND AND OBJECTIVE: Safinamide is a novel anti-parkinsonian drug with possible anti-dyskinetic properties. Parkinson's disease (PD) is a complex disease. The objective of this systematic review and meta-analysis is to evaluate the efficacy and safety of safinamide administration compared to placebo in PD patients on multiple outcomes.

METHODS

PubMed, EMBASE, Cochrane CENTRAL, LILACS, and trial databases were searched up to 23 December 2020 for randomized controlled studies (RCTs) comparing safinamide to placebo, alone or as add-on therapy in PD. Data were extracted from literature and regulatory agencies. Primary outcomes were ON-time without troublesome dyskinesia, OFF-time, and Unified Parkinson's Disease Rating Scale (UPDRS) section III (UPDRS-III). Secondary outcomes included any dyskinesia rating scale (DRS), ON-time with troublesome dyskinesia, UPDRS-II, and Parkinson's Disease Questionnaire 39 (PDQ-39). In order to estimate mean difference (MD) and odds ratios with 95% confidence intervals (CI), generic inverse variance and Mantel-Haenszel methods were used for continuous and dichotomous variables, respectively. Analyses were performed grouping by PD with (PDwMF) or without (PDwoMF) motor fluctuations, safinamide dose, and concomitant dopaminergic treatment. Summary of findings with GRADE were performed.

RESULTS

Six studies with a total of 2792 participants were identified. In PDwMF patients, safinamide 100 mg as add-on to levodopa (L-dopa) significantly increased ON-time without troublesome dyskinesia (MD = 0.95 h; 95% CI from 0.41 to 1.49), reduced OFF-time (MD = - 1.06 h; 95% CI from - 1.60 to - 0.51), and improved UPDRS-III (MD = - 2.77; 95% CI from - 4.27 to - 1.28) with moderate quality of evidence. Similar results were observed for the 50 mg dose. However, the quality of evidence was moderate only for ON-time without troublesome dyskinesia, whereas for OFF-time and UPDRS-III was low. In PDwoMF patients taking a single dopamine agonist, safinamide 100 mg resulted in little to no clinically significant improvement in UPDRS-III (MD = - 1.84; 95% CI from - 3.19 to - 0.49), with moderate quality of evidence. Conversely, in PDwoMF patients, the 200 mg and 50 mg doses showed nonsignificant improvement in UPDRS-III, with very low and moderate quality of evidence, respectively. In PDwMF patients taking safinamide 100 mg or 50 mg, nonsignificant differences were observed for ON-time with troublesome dyskinesia and DRS, with high and low quality of evidence, respectively. In the same patients, UPDRS-II was significantly improved at the 100 mg and 50 mg dose, with high and moderate quality of evidence. In PDwoMF, UPDRS-II showed a little yet significant difference only at 100 mg, with low quality of evidence. PDQ-39 resulted significantly improved only with the 100 mg dose in PDwMF, with low quality of evidence.

CONCLUSION

Overall, safinamide is effective in PDwMF patients taking L-dopa both at 100 and 50 mg daily. Evidence for efficacy in early PD is limited. Further trials are needed to better evaluate the anti-dyskinetic properties of safinamide.

Rasagiline monotherapy in early Parkinson's disease: A phase 3, randomized study in Japan

BACKGROUND

Rasagiline is a monoamine oxidase type-B inhibitor in development in Japan for Parkinson's disease (PD). The objective of this Phase 3, randomized, double-blind study was to evaluate the efficacy and safety of rasagiline in Japanese patients with early PD (NCT02337725).

METHODS

Patients were 30-79 years old with a diagnosis of PD within 5 years. Following a two-week placebo run-in period, patients were randomized 1:1 to receive rasagiline (1 mg/day) or placebo for up to 26 weeks. The primary endpoint was change from baseline in the MDS-UPDRS Part II + III total score (TS). Secondary endpoints included the MDS-UPDRS Parts II + III, III, II, and I TS and safety.

RESULTS

In total, 118 patients were randomized to rasagiline and 126 to placebo. Patient characteristics at baseline were similar in both groups. The change from baseline in the MDS-UPDRS Part II + III TS was significantly greater in the rasagiline vs. placebo group (rasagiline-placebo: -6.39, 95% CI: -8.530, -4.250; P < 0.0001). The mean changes from baseline in the MDS-UPDRS Part II + III, Part III and Part II TS were lower at treatment visits between weeks 6 and 26 in the rasagiline vs. placebo groups. The overall incidence of treatment-emergent adverse events (TEAEs) was 62.4% and 52.4% in the rasagiline and placebo groups, respectively; most frequent TEAE was nasopharyngitis (15.4% and 15.1%).

CONCLUSION

Treatment with oral rasagiline 1 mg/day was effective and well-tolerated in Japanese patients with early PD, with a significantly greater improvement in the MDS-UPDRS Part II + III TS vs. placebo, and a similar safety profile.

Efficacy of rasagiline for the treatment of Parkinson's disease: an updated meta-analysis

OBJECTIVE

Rasagiline is a second-generation potent selective inhibitor of monoamine oxidase-B. The aim of the study was to analyze the effectiveness of rasagiline in treatment of Parkinson's disease (PD), both as monotherapy and combination therapy.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 9 March 2016 using the keywords: Rasagiline, Azilect, Parkinson's disease. Randomized controlled trials of patients with PD who were randomized to treatment with rasagiline or placebo were included. Outcomes were unified Parkinson's disease rating scale (UPDRS) and the three subscales.

RESULTS

Ten studies fulfilled the inclusion criteria and 2709 patients were evaluated. The overall analysis revealed a significant improvement in change of total UPDRS scores in 1 mg/day and 2 mg/day rasagiline groups compared to placebo. Significant improvement in Part I (Mentation) of UPDRS scores was observed in 1 mg/day, but not in 2 mg/day rasagiline treatment group. Part II (ADL) and Part III (Motor) subscales significantly improved with both doses of rasagiline. Both monotherapy and combination therapy significantly improved total UPDRS scores.

CONCLUSIONS

Our results confirm the efficacy of rasagiline in PD. Further studies are required to establish the optimal dose of rasagiline, as well as to determine its effectiveness in different combination therapy protocols. KEY MESSAGES Rasagiline treatment was associated with significant improvement of UPDRS scores and the scores of the subscales. Both monotherapy and combination therapy significantly improved total UPDRS scores. Effect of rasagiline on total UPDRS scores was not dose-dependent.

Light-Up Probes Based on Fluorogens with Aggregation-Induced Emission Characteristics for Monoamine Oxidase-A Activity Study in Solution and in Living Cells

Fluorogens with aggregation-induced emission (AIEgens) have emerged as a powerful and versatile platform for the development of novel biosensors. In this study, a series of water-soluble fluorescent probes based on tetraphenylethylene (TPE) were designed and synthesized for the detection of monoamine oxidases (MAOs) based on specific interactions between the probes and the proteins. Among the six probes developed, t-TPEM displays a significant fluorescence increase upon introduction of MAOs. Of particular significance is that the fluorescence of t-TPEM in the presence of MAO-A is 21-fold higher than other proteins including MAO-B. Lineweaver-Burk plots reveal that t-TPEM acts as an uncompetitive inhibitor of MAO-A with Ki = 17.1 μM, which confirms its good binding affinity toward MAO-A. Furthermore, a cell imaging experiment reveals that t-TPEM is able to selectively monitor the activity of MAO-A which is localized in mitochondria of MCF-7 cells.

Identification and genotoxicity evaluation of two carbamate impurities in rasagiline

During the synthesis of a second-generation monoamine oxidase-B inhibitor rasagiline, two unknown impurities (impurity A and impurity B) were detected and isolated by preparative liquid chromatography.

Impact of Pharmacotherapy on Quality of Life in Patients with Parkinson's Disease

Quality of life (QoL) is a patient-reported outcome frequently included in Parkinson's disease (PD) clinical trials as a secondary or tertiary endpoint. However, QoL is an important variable that reflects the impact of disease and treatment from the patients' perspective. In a chronic, neurodegenerative disease such as PD, with a wide range of complex symptoms, QoL provides valuable and comprehensive information on the patients' health status. This narrative review aims to evaluate the effect of specific PD treatments currently in use on patients' QoL measured with the Parkinson's Disease Questionnaire, 39-item (PDQ-39) or 8-item (PDQ-8) version. A quantification of this effect is provided by calculation of the relative change and effect size. These two parameters allow an intuitive standardized approach to the importance of change based on its magnitude. Some high-quality studies (Level I) were found for levodopa (immediate- or extended-release formulations), levodopa with added-on catechol-O-methyltransferase (COMT) inhibitors, levodopa/carbidopa gel for intestinal infusion, some dopamine agonists (ropinirole, cabergoline, pergolide), and the monoamine oxidase B (MAO-B) inhibitor safinamide. As a whole, these studies found a beneficial effect of variable magnitude, weak to moderate, on patients' QoL. Studies with a lower level of evidence or not providing enough data to estimate relative change and effect size, including those for the apomorphine subcutaneous pump, also reported improvement of QoL, but the evidence was insufficient to confirm the effect. More high-quality studies focused on QoL are needed to determine the real impact of PD drug treatments for this important outcome.

A multi-center screening trial of rasagiline in patients with amyotrophic lateral sclerosis: Possible mitochondrial biomarker target engagement

Rasagiline, a monoamine oxidase B inhibitor, slowed disease progression in the SOD1 mouse, and in a case series of patients with amyotrophic lateral sclerosis (ALS). Here we determine whether rasagiline is safe and effective in ALS compared to historical placebo controls, and whether it alters mitochondrial biomarkers. We performed a prospective open-label, multicenter screening trial of 36 ALS patients treated with 2 mg oral rasagiline daily for 12 months. Outcomes included the slope of deterioration of the revised ALS Functional Rating Scale (ALSFRS-R), adverse event monitoring, time to treatment failure, and exploratory biomarkers. Participants experienced no serious drug-related adverse events, and the most common adverse event was nausea (11.1%). Rasagiline did not improve the rate of decline in the ALSFRS-R; however, differences in symptom duration compared to historical placebo controls differentially affected ALSFRS-R slope estimates. Rasagiline changed biomarkers over 12 months, such that the mitochondrial membrane potential increased (JC-1 red/green fluorescent ratio 1.92, p = 0.0001) and apoptosis markers decreased (Bcl-2/Bax ratio 0.24, p < 0.0001). In conclusion, engagement of exploratory biomarkers and questions about comparability of baseline characteristics lead us to recommend a further placebo-controlled trial.

Glycogen synthase kinase-3 beta (GSK-3β) signaling: Implications for Parkinson's disease

Glycogen synthase kinase 3 (GSK-3) dysregulation plays an important role in the pathogenesis of numerous disorders, affecting the central nervous system (CNS) encompassing both neuroinflammation and neurodegenerative diseases. Several lines of evidence have illustrated a key role of the GSK-3 and its cellular and molecular signaling cascades in the control of neuroinflammation. Glycogen synthase kinase 3 beta (GSK-3β), one of the GSK-3 isomers, plays a major role in neuronal apoptosis and its inhibition decreases expression of alpha-Synuclein (α-Synuclein), which make this kinase an attractive therapeutic target for neurodegenerative disorders. Parkinson's disease (PD) is a chronic neurodegenerative movement disorder characterized by the progressive and massive loss of dopaminergic neurons by neuronal apoptosis in the substantia nigra pars compacta and depletion of dopamine in the striatum, which lead to pathological and clinical abnormalities. Thus, understanding the role of GSK-3β in PD will enhance our knowledge of the basic mechanisms underlying the pathogenesis of this disorder and facilitate the identification of new therapeutic avenues. In recent years, GSK-3β has been shown to play essential roles in modulating a variety of cellular functions, which have prompted efforts to develop GSK-3β inhibitors as therapeutics. In this review, we summarize GSK-3 signaling pathways and its association with neuroinflammation. Moreover, we highlight the interaction between GSK-3β and several cellular processes involved in the pathogenesis of PD, including the accumulation of α-Synuclein aggregates, oxidative stress and mitochondrial dysfunction. Finally, we discuss about GSK-3β inhibitors as a potential therapeutic strategy in PD.

Eryptosis as a marker of Parkinson's disease

A major trend in recent Parkinson's disease (PD) research is the investigation of biological markers that could help in identifying at-risk individuals or to track disease progression and response to therapies. Central to this is the knowledge that inflammation is a known hallmark of PD and of many other degenerative diseases. In the current work, we focus on inflammatory signalling in PD, using a systems approach that allows us to look at the disease in a more holistic way. We discuss cyclooxygenases, prostaglandins, thromboxanes and also iron in PD. These particular signalling molecules are involved in PD pathophysiology, but are also very important in an aberrant coagulation/hematology system. We present and discuss a hypothesis regarding the possible interaction of these aberrant signalling molecules implicated in PD, and suggest that these molecules may affect the erythrocytes of PD patients. This would be observable as changes in the morphology of the RBCs and of PD patients relative to healthy controls. We then show that the RBCs of PD patients are indeed rather dramatically deranged in their morphology, exhibiting eryptosis (a kind of programmed cell death). This morphological indicator may have useful diagnostic and prognostic significance.

Mavoglurant as a treatment for Parkinson's disease

INTRODUCTION

A major unresolved issue in the Parkinson's disease (PD) treatment is the development of l-DOPA-induced dyskinesias (LIDs) as a side effect of chronic L-DOPA administration. Currently, LIDs are managed in part by reducing the L-DOPA dose or by the administration of amantadine. However, this treatment is only partially effective. A potential strategy, currently under investigation, is the coadministration of metabotropic glutamate receptor 5 (mGluR5) negative allosteric modulators (NAMs) and L-DOPA; a treatment that results in the improvement of dyskinesia symptoms and that permits reductions in l-DOPA dosage frequency.

AREAS COVERED

The authors examine the role of mGluR5 in the pathophysiology of PD and the potential use of mGluR5 NAM as an adjuvant therapy together with a primary treatment with L-DOPA. Specifically, the authors look at the mavoglurant therapy and the evidence presented through preclinical and clinical trials.

EXPERT OPINION

Interaction between mGluR5 NAM and L-DOPA is an area of interest in PD research as concomitant treatment results in the improvement of LID symptoms in humans, thus enhancing the patient's quality of life. However, few months ago, Novartis decided to discontinue clinical trials of mavoglurant for the treatment of LID, due to the lack of efficacy demonstrated in trials NCT01385592 and NCT01491529, although no safety concerns were involved in this decision. Nevertheless, the potential application of mGluR5 antagonists as neuroprotective agents must be considered and further studies are warranted to better investigate their potential.

Comparison of the antileukaemic activity of 5 aza-2-deoxycytidine and arabinofuranosyl-cytosine in rats with myelocytic leukaemia

Using a Brown Norway rat leukaemia model (BNML), which is a realistic model of human myelocytic leukaemia, we compared the antileukaemic activity, influence on cell cycle kinetics and effect on normal haematopoiesis of 5 aza-2-deoxycytidine (aza-dC) and arabinofuranosyl-cytosine (ara-C). The antileukaemic activity was evaluated by means of a survival study. For aza-dC a dose-response relationship was demonstrated for doses up to 50 mg kg-1 (3 times q 12 h); a higher dose resulted in only a slight increase in median survival time (MST). For ara-C a weak dose-response relationship was observed. At the maximum dose of aza-dC and ara-C tested, aza-dC induced a 10-day longer survival time than ara-C, which means 2 logs more of leukaemic cell kill for aza-dC. By means of flow cytometric analysis and a 3HTdR uptake study it was shown that aza-dC does not influence the cell cycle kinetics in the first 24 h after exposure, in contrast to ara-C which caused the characteristic G1/S blockage and synchronization. The influence of aza-dC and ara-C on normal haematopoiesis was evaluated with the CFU-S assay. The dose-response curve for CFU-S did not show a significant difference in stem cell cytotoxicity between aza-dC and ara-C. In the BNML model aza-dC is a much more effective antileukaemic agent than ara-C, while the toxic effect on normal haematopoiesis is comparable to that of ara-C.