Rasagiline combined with levodopa therapy versus levodopa monotherapy for patients with Parkinson's disease: a systematic review

BDNF/TrkB activators in Parkinson's disease: A new therapeutic strategy

Parkinson's disease (PD) is a neurodegenerative disorder of the brain and is manifested by motor and non-motor symptoms because of degenerative changes in dopaminergic neurons of the substantia nigra. PD neuropathology is associated with mitochondrial dysfunction, oxidative damage and apoptosis. Thus, the modulation of mitochondrial dysfunction, oxidative damage and apoptosis by growth factors could be a novel boulevard in the management of PD. Brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin receptor kinase type B (TrkB) are chiefly involved in PD neuropathology. BDNF promotes the survival of dopaminergic neurons in the substantia nigra and enhances the functional activity of striatal neurons. Deficiency of the TrkB receptor triggers degeneration of dopaminergic neurons and accumulation of α-Syn in the substantia nigra. As well, BDNF/TrkB signalling is reduced in the early phase of PD neuropathology. Targeting of BDNF/TrkB signalling by specific activators may attenuate PD neuropathology. Thus, this review aimed to discuss the potential role of BDNF/TrkB activators against PD. In conclusion, BDNF/TrkB signalling is decreased in PD and linked with disease severity and long-term complications. Activation of BDNF/TrkB by specific activators may attenuate PD neuropathology.

Promising biomarkers and therapeutic targets for the management of Parkinson's disease: recent advancements and contemporary research

Parkinson's disease (PD) is one of the progressive neurological diseases which affect around 10 million population worldwide. The clinical manifestation of motor symptoms in PD patients appears later when most dopaminergic neurons have degenerated. Thus, for better management of PD, the development of accurate biomarkers for the early prognosis of PD is imperative. The present work will discuss the potential biomarkers from various attributes covering biochemical, microRNA, and neuroimaging aspects (α-synuclein, DJ-1, UCH-L1, β-glucocerebrosidase, BDNF, etc.) for diagnosis, recent development in PD management, and major limitations with current and conventional anti-Parkinson therapy. This manuscript summarizes potential biomarkers and therapeutic targets, based on available preclinical and clinical evidence, for better management of PD.

Investigating the Targeting Power to Brain Tissues of Intranasal Rasagiline Mesylate-Loaded Transferosomal In Situ Gel for Efficient Treatment of Parkinson's Disease

Rasagiline mesylate (RSM) is a hydrophilic drug with poor oral bioavailability (36%) because of hepatic first-pass metabolism. The present study focuses on delivering RSM directly to the brain through its inclusion within transferosomal in situ gel administered through the intranasal (IN) route. Transferosomes were formed by the thin-film hydration method with the aid of Design-Expert^® software by varying the edge activator (EA) type in the absence or presence of cholesterol. By desirability calculations, the optimum formulation was composed of phosphatidylcholine and sodium deoxycholate as an EA (5:1% w/w) with no cholesterol. The optimum formulation was 198.63 ± 34.98 nm in size and displayed an entrapment efficiency of 95.73 ± 0.09%. Transmission electron microscopy revealed discrete and spherical vesicles. Optimized transferosomes were further incorporated into an in situ gel composed of 0.5% pectin, 15% Pluronic^® F-127, and 5% Pluronic^® F-68 and tested for the in vivo performance. The systemic as well as brain kinetics were assessed in rats by comparing the IN-administered in situ gel to the IV aqueous solution. The optimum in situ gel showed safety and biocompatibility on rats' nasal mucosa with enhanced brain bioavailability (131.17%). Drug targeting efficiency and direct transport percentage indices (304.53% and 67.16%, respectively) supported successful brain targeting offering direct nose-to-brain drug delivery.

Rasagiline as Adjunct to Levodopa for Treatment of Parkinson’s Disease: A Systematic Review and Meta-Analysis

Background

Rasagiline is a selective, irreversible monoamine oxidase type B inhibitor used as monotherapy in early Parkinson's disease and as an adjunct therapy to levodopa in Parkinson's disease with motor fluctuations.

Objectives

This meta-analysis aimed to provide updated evidence on the efficacy for motor and nonmotor symptoms and the safety of rasagiline/levodopa versus levodopa in patients with Parkinson's disease experiencing motor fluctuations.

Methods

A systematic literature search was conducted (January 18-19, 2021) using PubMed, Cochrane Library, EMBASE, Web of Science, and Google Scholar to identify randomized controlled trials comparing rasagiline/levodopa versus placebo/levodopa in patients with Parkinson's disease experiencing motor fluctuations. Outcomes included change in wearing-off time, Unified Parkinson's Disease Rating Scale (UPDRS)/Movement Disorder Society-UPDRS (MDS-UPDRS) II and III scores, treatment-emergent adverse events (TEAEs), and Parkinson's Disease Questionnaire (PDQ-39) summary index score. A random effect model was used to estimate the treatment effects.

Results

Six studies were included (1912 patients). Significant improvements in wearing-off time (standardized mean difference [SMD]: −0.50, 95% confidence interval [CI]: –0.92 to –0.09, p = 0.002), levodopa dosage (SMD: −0.18, 95% CI: −0.35 to –0.01, p = 0.041), UPDRS/MDS-UPDRS II (SMD: −0.39, 95% CI: −0.52 to –0.25, p < 0.0001), UPDRS/MDS-UPDRS III (SMD: −0.30, 95% CI: −0.44 to –0.16, p < 0.0001), and PDQ-39 summary index score (SMD: –0.21, 95% CI: –0.37 to –0.04, p = 0.013) were observed with rasagiline/levodopa versus placebo/levodopa. The incidence of TEAEs did not differ between treatments (risk ratio: 1.13, 95% CI: 0.98–1.30, p = 0.093).

Conclusions

This meta-analysis further indicated the superiority of rasagiline/levodopa in improving motor and nonmotor symptoms of Parkinson's disease, with a similar safety profile to that of levodopa in Parkinson's disease with motor fluctuations.

A critical appraisal of MAO-B inhibitors in the treatment of Parkinson's disease

Since the 1980s, the MAO-B inhibitors have gained considerable status in the therapy of the Parkinson's disease. In addition to the symptomatic effect in mono- and combination therapies, a neuroprotective effect has repeatedly been a matter of some discussion, which has unfortunately led to a good many misunderstandings. Due to potential interactions, selegiline has declined in significance in the field. For the MAO-B inhibitor safinamide, recently introduced to the market, an additional inhibition of pathological release of glutamate has been postulated. At present, rasagiline and selegiline are being administered in early therapy as well as in combination with levodopa. Safinamide has been approved only for combination therapy with levodopa when motor fluctuations have occurred. MAO-B inhibitors are a significant therapeutic option for Parkinson's disease, an option which is too often not appreciated properly.

Chinese herbal medicine treatment based on subgroup differentiation as adjunct therapy for Parkinson’s disease: study protocol of a pilot add-on, randomised, controlled, pragmatic clinical trial

Background

Parkinson’s disease (PD) is a prevalent and debilitating condition. Conventional medications cannot control all symptoms and may inflict adverse effects. A survey reported that Chinese herbal medicine (CHM) is frequently sought. Existing CHM trials were contradictory and often of poor quality due to lack of methodological rigor. A national clinical guideline was drafted in China with diagnostic criteria and treatment strategy of Chinese medicine (CM) patterns subgroups of PD. The suggested CHM were found to exhibit neuroprotective effect in in vitro and in vivo studies. This trial aims to preliminarily assess the effect of CHM prescribed based on pattern differentiation on PD symptoms and patients’ quality of life, and evaluate the feasibility of the trial design for a future large-scale trial.

Methods

This trial will be a pilot assessor- and data analyst blind, add-on, randomised, controlled, pragmatic clinical trial. 160 PD patients will be recruited and randomised into treatment or control groups in a 1:1 ratio. The trial will be conducted over 32 weeks. PD patients in the treatment group will be stratified into subgroups based on CM pattern and receive CHM accordingly in addition to conventional medication (ConM). The control group will receive ConM only. The primary outcome will be part II of the Movement Disorder Society Sponsored Revision of Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). Secondary outcomes will include part and total scores of MDS-UPDRS, domain and total scores of Non-motor symptom scale (NMSS). Adverse events will be monitored by monthly follow-ups and questionnaires. Mixed models will be used to analyse data by Jamovi and R.

Expected outcomes

The success of our trial will show that the pragmatic design with subgroup differentiation is feasible and can produce reliable results. It will also provide preliminary data of the effect of CHM on improving clinical outcomes and quality of PD patients. Data collected will be used to optimize study design of the future large-scale clinical study.

Ethical clearance

Ethical clearance of this study was given by the Research Ethics Committee of Hong Kong Baptist University (REC/20-21/0206).

Trial registration This trial is registered on ClinicalTrials.gov (NCT05001217, Date: 8/10/2021, https://clinicaltrials.gov/ct2/show/NCT05001217). Type of manuscript: clinical trial protocol (date: 3^rd November, 2021, version 1)

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00572-0.

Efficacy and safety of combination therapy with pramipexole and levodopa vs levodopa monotherapy in patients with Parkinson disease: A systematic review and meta-analysis

BACKGROUND

Pramipexole (P) or levodopa (L) treatment has been suggested as a therapeutic method for Parkinson disease (PD) in many clinical studies. Nonetheless, the combined effects of 2 drugs for PD patients are not completely understood.The aim of this research was to evaluate the clinical efficacy and safety of P plus L (P+L) combination therapy in the treatment of PD compared to that of L monotherapy, in order to confer a reference for clinical practice.

METHODS

Randomized controlled trials (RCTs) of P+L for PD published up to April, 2020 were retrieved. Standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (CI) were calculated and heterogeneity was measured with the I2 test. Sensitivity analysis was also carried out. The outcomes of interest were as follows: the efficacy, unified Parkinson disease rating scale (UPDRS) scores, Hamilton depression rating scale score or adverse events.

RESULTS

Twenty-four RCTs with 2171 participants were included. Clinical efficacy of P+L combination therapy was significantly better than L monotherapy (9 trials; OR 4.29, 95% CI 2.78 to 6.64, P < .00001). Compared with L monotherapy, the pooled effects of P+L combination therapy on UPDRS score were (22 trials; SMD -1.31, 95% CI -1.57 to -1.04, P < .00001) for motor UPDRS score, (16 trials; SMD -1.26, 95% CI -1.49 to -1.03, P < .00001) for activities of daily living UPDRS score, (12 trials; SMD -1.02, 95% CI -1.27 to -0.77, P < .00001) for mental UPDRS score, (10 trials; SMD -1.54, 95% CI -1.93 to -1.15, P < .00001) for complication UPDRS score. The Hamilton depression rating scale score showed significant decrease in the P+L combination therapy compared to L monotherapy (12 trials; SMD -1.56, 95% CI -1.90 to -1.22, P < .00001). In contrast to L monotherapy, P+L combination therapy reduced the number of any adverse events obviously in PD patients (16 trials; OR 0.36, 95% CI 0.27 to 0.50, P < .00001).

CONCLUSIONS

P+L combination therapy is superior to L monotherapy for improvement of clinical symptoms in PD patients. Moreover, the safety profile of P+L combination therapy is better than that of L monotherapy. Further well-designed, multicenter RCTs needed to identify these findings.

The role of pramipexole in the treatment of patients with depression and Parkinson's disease: A meta-analysis of randomized controlled trials

OBJECTIVE

The aim of this report was to evaluate the clinical efficacy and safety of pramipexole therapy for patients with depression and Parkinson's disease (dPD), in order to confer a reference for clinical practice.

METHODS

Randomized controlled trials (RCTs) of pramipexole for dPD published up to June 2020 were retrieved. Standardised mean difference (SMD), risk ratio (RR), and 95 % confidence interval (CI) were calculated. The outcomes included efficacy, Hamilton depression rating scale (HAMD) score, unified Parkinson's disease rating scale (UPDRS) scores, self-rating depression scale (SDS) score, self-rating anxiety scale (SAS) score or adverse events.

RESULTS

Eighteen RCTs with 1789 participants were included. Clinical efficacy in pramipexole treatment group was significantly better than control group (RR 1.26, 95 % CI 1.20-1.33, P < 0.00001). Compared with control group, the pooled effects of pramipexole therapy on depression were (SMD -1.90, 95 % CI -2.58 to -1.23, P < 0.00001) for HAMD score, (SMD -3.94, 95 % CI -4.73 to -3.15, P < 0.00001) for SDS score, pramipexole therapy also decreased SAS score markedly (P < 0.0001). Compared with control group, the pooled effects of pramipexole on motor UPDRS score and activities of daily living UPDRS score were statistically significant (P < 0.01). Furthermore, pramipexole therapy didn't increase the number of any adverse events in dPD patients (RR 0.72, 95 % CI 0.37-1.41, P = 0.34).

CONCLUSIONS

Pramipexole therapy can alleviate depressive symptoms and motor dysfunction in dPD patients, and there were no more side effects associated with drug intervention. These findings should be further validated by high-quality and well-designed RCTs.

Effects of atorvastatin on the insulin resistance in women of polycystic ovary syndrome: A systematic review and meta-analysis

BACKGROUND

Atorvastatin treatment has been suggested as a therapeutic method for women with polycystic ovary syndrome (PCOS) in many clinical studies. Nonetheless, the effects of atorvastatin on insulin resistance in PCOS patients still remain controversial.

OBJECTIVE

The aim of this report was to evaluate the effects of atorvastatin therapy on the insulin resistance in the treatment of PCOS compared to that of placebo, in order to confer a reference for clinical practice.

METHODS

Randomized controlled trials (RCTs) of atorvastatin for PCOS published up to August, 2020 were searched. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated, and heterogeneity was measured by the I2 test. Sensitivity analysis was also carried out. The outcomes of interest were as follows: fasting glucose concentration, fasting insulin level, homeostasis model assessment of insulin resistance (HOMA-IR) or body mass index (BMI) value.

RESULTS

Nine RCTs with 406 participants were included. The difference of fasting glucose concentration in PCOS patients between atorvastatin group and placebo group was not statistically significant (8 trials; SMD -0.06, 95% CI -0.31 to 0.20, P = .66). PCOS patients in atorvastatin group had lower fasting insulin level than those in placebo group (7 trials; SMD -1.84, 95% CI -3.06 to -0.62, P < .003). The homeostasis model assessment of insulin resistance (HOMA-IR) value showed significant decrease in the atorvastatin therapy compared to placebo (6 trials; SMD -4.12, 95% CI -6.00 to -2.23, P < .0001). In contrast to placebo, atorvastatin therapy did not decrease the BMI value significantly in PCOS patients (7 trials; SMD 0.12, 95% CI -0.07 to 0.31, P = .22).

CONCLUSIONS

Atorvastatin therapy can reduce insulin resistance in the treatment of patients with PCOS. In addition, further large-sample, multi-center RCTs are needed to identify these findings.

Comparison of pramipexole and levodopa/benserazide combination therapy versus levodopa/benserazide monotherapy in the treatment of Parkinson's disease: a systematic review and meta-analysis

The purpose of this research was to evaluate the clinical efficacy and safety of pramipexole plus levodopa/benserazide (P+LB) combination therapy in the treatment of Parkinson's disease (PD) compared to that of LB monotherapy, in order to confer a reference for clinical practice. Randomized controlled trials (RCTs) of P+LB for PD published up to April 2020 were retrieved. Heterogeneity and sensitivity analysis were executed. Twenty-nine RCTs with 3017 participants were included. Clinical efficacy of P+LB combination therapy was significantly better than LB monotherapy (RR 1.27, 95% CI 1.22 to 1.32, P<0.00001). Compared with LB monotherapy, the pooled effects of P+LB combination therapy on UPDRS score were (SMD -1.41, 95% CI -1.71 to -1.11, P<0.00001) for motor UPDRS score, (SMD -1.65, 95% CI -2.25 to -1.04, P<0.00001) for activities of daily living UPDRS score, (SMD -2.20, 95% CI -3.32 to -1.09, P=0.0001) for mental UPDRS score, and (SMD -1.60, 95% CI -2.06 to -1.15, P<0.00001) for complication UPDRS score. The HAMD score showed significant decrease in the P+LB combination therapy compared to LB monotherapy (SMD -1.32, 95% CI -1.80 to -0.84, P<0.00001). In contrast to LB monotherapy, P+LB combination therapy decreased the number of any adverse events obviously in PD patients (RR 0.53, 95% CI 0.45 to 0.63, P<0.00001). In conclusion, P+LB combination therapy is superior to LB monotherapy for improvement of clinical symptoms in PD patients. Moreover, the safety profile of P+LB combination therapy is better than that of LB monotherapy. Further well-designed, multi-center RCTs needed to identify these findings.

Identification of biomarkers associated with Parkinson's disease by gene expression profiling studies and bioinformatics analysis

Parkinson's disease (PD) is associated with a selective loss of the neurons in the midbrain area called the substantia nigra pars compacta and the loss of projecting nerve fibers in the striatum. Predominant pathological hallmarks of PD are the degeneration of discrete neuronal populations and progressive accumulation of α-synuclein-containing intracytoplasmic inclusions called Lewy bodies and dystrophic Lewy neuritis. There is currently no therapy to terminate or delay the neurodegenerative process as the exact mechanisms underlying the pathogenesis of PD require further investigation. The identification and validation of novel biomarkers for the diagnosis of PD is a great challenge using contemporary approaches and optimizing sampling handling as well as interpretation using bioinformatics analysis. In this review, recent evidences associated with multi-omic data-sets and molecular mechanisms underlying PD are examined. A combined mapping of several transcriptional evidences could establish a patient-specific signature for early diagnose of PD though eligible systems biology tools, which can also help develop effective drug-based therapeutic approaches.