New insights into pathogenesis of l-DOPA-induced dyskinesia

20-Week Intramuscular Toxicity Study of Rotigotine Behenate Extended-Release Microspheres for Injection via Intramuscular Injection in Cynomolgus Monkeys

Continuous dopaminergic stimulation (CDS) has become an important strategy for the development of drugs to treat Parkinson's disease(PD). Rotigotine behenate extended-release microspheres (RBEM) for injection represents a new treatment regime for CDS and is being applied for clinical trial. Our study in cynomolgus monkeys was a 20-week repeat dose toxicity investigation with RBEM at dosages of 90, 180, 360, with a 12-week recovery period. The results observed some irritations in the application site and surrounding tissues in Placebo microspheres and each dose of RBEM, was accompanied with increased white blood count and fibrinogen. RBEM-treated monkeys were additionally noted with a pharmacological action-related decrease in prolactin. These findings showed certain reversibility after the 12-week recovery phase. No clear sex difference was noted in the plasma exposure to rotigotine. The exposure generally increased in a dose-proportional manner. In summary, major toxicological effects are associated with the dopamine agonist-related properties of rotigotine, and the removal of foreign bodies caused by p oly(lactide-co-glycolide) (PLGA)and sodium carboxymethyl cellulose (SCMC), and the no-observed-adverse-effect-level (NOAEL) was 360 mg/kg.

Dynamic Regulation of DNA Methylation and Brain Functions

DNA cytosine methylation is a principal epigenetic mechanism underlying transcription during development and aging. Growing evidence suggests that DNA methylation plays a critical role in brain function, including neurogenesis, neuronal differentiation, synaptogenesis, learning, and memory. However, the mechanisms underlying aberrant DNA methylation in neurodegenerative diseases remain unclear. In this review, we provide an overview of the contribution of 5-methycytosine (5mC) and 5-hydroxylcytosine (5hmC) to brain development and aging, with a focus on the roles of dynamic 5mC and 5hmC changes in the pathogenesis of neurodegenerative diseases, particularly Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Identification of aberrant DNA methylation sites could provide potential candidates for epigenetic-based diagnostic and therapeutic strategies for neurodegenerative diseases.

Comparison of Botulinum neurotoxin efficiency in dystonia associated with Parkinson's disease and atypical parkinsonism: a retrospective study with a self-reported improvement scale

Botulinum neurotoxin (BoNT) is a useful therapeutic option to treat dystonic manifestations. Data on its efficiency on dystonia associated with Parkinson's disease (PD) or atypical parkinsonism (AP) are scarce and no comparison of the efficiency of BoNT has been performed between these diseases and between the different localizations of dystonia in these pathologies. We retrospectively collected from patients' medical records the result of 611 BoNT injections in 63 dystonic parkinsonian patients (44 PD and 19 AP) using a self-reported clinical improvement scale and duration of effect. Using these data, we modeled the degree of improvement and its duration after BoNT treatment with a linear mixed model. This allowed us to assess the influence of clinical parameters on the reported treatment efficiency. On a scale from 0 to 100, patients with PD and AP, respectively, report a mean improvement of 69% and 55% after BoNT injection and it is similar regarding the different localizations of dystonia. Duration of effect is, however, longer in PD compared to AP (P = 0.023). Patients' demographic and clinical characteristics had no effect on the degree of improvement or duration of effect. Overall, our results support the use of BoNT in the various dystonic phenomena associated with degenerative parkinsonian syndromes. Shorter delays between injection sessions should be considered in AP compared to PD.Trial registration: This study was registered on Clinicaltrial.gov (NCT04948684).

Phytocannabinoids and Cannabis-Based Products as Alternative Pharmacotherapy in Neurodegenerative Diseases: From Hypothesis to Clinical Practice

Historically, Cannabis is one of the first plants to be domesticated and used in medicine, though only in the last years the amount of Cannabis-based products or medicines has increased worldwide. Previous preclinical studies and few published clinical trials have demonstrated the efficacy and safety of Cannabis-based medicines in humans. Indeed, Cannabis-related medicines are used to treat multiple pathological conditions, including neurodegenerative disorders. In clinical practice, Cannabis products have already been introduced to treatment regimens of Alzheimer’s disease, Parkinson’s disease and Multiple Sclerosis’s patients, and the mechanisms of action behind the reported improvement in the clinical outcome and disease progression are associated with their anti-inflammatory, immunosuppressive, antioxidant, and neuroprotective properties, due to the modulation of the endocannabinoid system. In this review, we describe the role played by the endocannabinoid system in the physiopathology of Alzheimer, Parkinson, and Multiple Sclerosis, mainly at the neuroimmunological level. We also discuss the evidence for the correlation between phytocannabinoids and their therapeutic effects in these disorders, thus describing the main clinical studies carried out so far on the therapeutic performance of Cannabis-based medicines.