CNS & Neurological Disorders - Drug Targets (Formerly Current Drug Targets - CNS & Neurological Disorders) - Volume 22, Issue 3, 2023

Unani system of medicine is based on the use of natural plant products. Unani polyherbal formulations (UPFs) are being prescribed for the treatment of various ailments. The preparations of the UPFs also required the animal products such as honey and umber. UPFs have been reported to cure various diseases but still lack scientific credibility. The Unani system is based on the holistic approach; the synergistic role of the compounds has been suggested to play a protective role against the illness. The present review has compiled the studies carried out on UPFs used to treat various diseases with special reference to neurodegenerative ailments. The exorbitant cost of conventional treatment has led the world to think towards alternative therapy with less cost and no or little side effects compared to conventional treatments. More research is required for UPFs on the experimental models along with the case controlled studies in order to establish UPFs in the mainstream of treatment.

Parkinson’s disease (PD) is a progressive neurodegenerative disease characterised by reduced dopamine levels in the substantial nigra. This may lead to typical motor features such as bradykinesia, resting tremors and rigid muscles, as well as non-motor symptoms such as neuropsychiatric symptoms, sleep disorders, autonomic dysfunction, and sensory disturbances. Inhibitors of monoamine oxidase B (MAO-B) are used to alleviate symptoms by reducing monoamine oxidase-catalysed degradation of dopamine; hence, preserving functional levels of dopamine. The very first MAO-B inhibitor used therapeutically was selegiline, followed by rasagiline, its indane derivative which has superior efficacy and selectivity. Both inhibitors can be used as monotherapy or in combination with other anti- Parkinson drugs. Safinamide, a reversible MAO-B inhibitor that utilises both dopaminergic and non-dopaminergic mechanisms, was recently approved by the European Medicines Agency (EMA) (2015) and U.S. FDA (2017) as an add-on therapy for patients with mid- or late-stage Parkinson’s disease. Furthermore, MAO-B inhibitors were found to be associated with potential neuroprotective and disease modifying effects. However, evidence of their efficacy and role in PD models is scarce and warrants further investigation.

Parkinson’s disease (PD) is the second most debilitating neurodegenerative movement disorder. It is characterized by the presence of fibrillar alpha-synuclein amassed in the neurons, known as Lewy bodies. Certain cellular and molecular events are involved, leading to the degeneration of dopaminergic neurons. However, the origin and implication of such events are still uncertain. Nevertheless, the role of microRNAs (miRNAs) as important biomarkers and therapeutic molecules is unquestionable. The most challenging task by far in PD treatment has been its late diagnosis followed by therapeutics. miRNAs are an emerging hope to meet the need of early diagnosis, thereby promising an improved movement symptom and prolonged life of the patients. The continuous efforts in discovering the role of miRNAs could be made possible by the utilisation of various animal models of PD. These models help us understand insights into the mechanism of the disease. Moreover, miRNAs have been surfaced as therapeutically important molecules with distinct delivery systems enhancing their success rate. This review aims at providing an outline of different miRNAs implicated in either PD-associated gene regulation or involved in therapeutics.

Multiple Sclerosis (MS) is a multifactorial, neurodegenerative, and inflammatory demyelination disease with incomplete remyelination in the CNS. It would be more informative to reveal the underlying molecular mechanisms of MS. Molecular mechanisms involving epigenetic changes play a pivotal role in this disease. Epigenetic changes impact gene expression without altering the underlying DNA sequence. The main epigenetic modifications that play a key role in the regulation of gene expression principally include DNA methylation, histone modifications, and microRNA- associated post-transcriptional gene silencing. In this review, we summarize the dynamics of epigenetic changes and their relation to environmental risk factors in MS pathogenesis. Studies suggest that epigenetic changes have a role in the development of MS and environmental risk factors, such as vitamin D, smoking, and Epstein-Barr virus infection seem to influence the development and susceptibility to MS. Investigating epigenetic and environmental factors can provide new opportunities for the molecular basis of the diseases, which shows complicated pathogenesis. Epigenetic research has the potential to complete our understanding of MS initiation and progression. Increased understanding of MS molecular pathways leads to new insights into potential MS therapies. However, there is a need for in vivo evaluation of the role of epigenetic factors in MS therapy. It would be more valuable to indicate the role of various epigenetic factors in MS.

Cenobamate is a novel antiseizure medication (ASM) commercially available in Europe and in the U.S. for the treatment of focal seizures in adults. The mechanisms responsible for its antiseizure activity include enhancement of the inactivated state of voltage-gated sodium channels with blockade of the persistent sodium current and positive allosteric modulation of GABAA receptors at a non-benzodiazepine binding site. Cenobamate has a high oral bioavailability that is not influenced by food intake. The terminal half-life is 50-60 hours, allowing for once-daily dosing. Cenobamate is a CYP2C19 inhibitor and an inducer of CYP3A4 and CYP2B6, and consequently, it can cause a number of drug-drug interactions. Efficacy and safety have been evaluated in two randomized, double-blind, placebo-controlled adjunctive therapy trials in adults with focal seizures. In both trials, cenobamate decreased significantly the frequency of focal seizures, with relatively high seizure freedom rates. Adverse events most commonly reported in double-blind trials included dizziness, somnolence, headache, fatigue, and diplopia. The occurrence of three cases of drug reaction with eosinophilia and systemic symptoms (DRESS) during early clinical development led to the conduction of a Phase 3 open-label long-term safety study in a total of 1339 patients. In this study, no serious idiosyncratic adverse reactions were observed using a start-low and go-slow approach. Further studies are required to determine whether the clinical activity profile of cenobamate extends to protection against other seizure types and to evaluate its efficacy and safety profile in special patient groups such as infants, children, the elderly, and patients with comorbid conditions.

Background: Neurodegenerative diseases, being rapidly increasing disorders and the seventh leading cause of death worldwide, have been a great challenge for researchers, affecting cognition, motor activity and other body functioning due to neurodegeneration. Several neurodegenerative diseases are caused by aggregation of proteins which induce the alteration of neuronal function leading to cell death. These proteins are amyloid-β peptide, tau, α-synuclein, and mHTT, which cause Alzheimer’s disease, Frontotemporal dementia, Corticobasal degeneration, Progressive supranuclear palsy, Parkinson’s disease, Multiple system atrophy, Dementia with Lewy-body and Huntington’s disease. Currently available treatments only reduce symptoms and increase life sustainability; however, they possess side effects and are ineffective in curing the diseases. Objective: Literature survey of neurodegenerative diseases and immunotherapeutic approaches is used to evaluate their pharmacological effects and future endeavours. Methods: A literature search was performed to find the relevant articles related to neurodegenerative diseases and immunotherapies. Clinical trials data were analysed from clinicaltrial.com. Results: According to the literature study, it was found that researchers have explored the effect of active and passive vaccines generated against amyloid-β, tau, α-synuclein and mHTT. Few clinical trials have shown severe side effects and terminated, despite that, few of them produced desirable effects for the treatment of AD and PD. Conclusion: Several immunotherapeutic trials have shown promising outcomes against amyloid-β, tau and α-synuclein. In addition, various preclinical studies against mHTT and prion proteins are under scrutinization. These clinical outcomes indicate a promising role of immunotherapies against neurodegenerative diseases.

Background: Depression and anxiety belong to a family of mental disturbances that have increased significantly in recent years. The etiology of both disorders comprises multiple and complex factors, from genetic background to environmental influence. Since depression and anxiety present severe symptoms, they represent a greater clinical burden and greater therapeutic difficulty. Currently, standardized diagnostic procedures for depression and anxiety allow for the addition of further treatments, including psychotherapy and/or pharmacological intervention, with effective outcomes. However, further steps should be considered with regard to consideration of the endocannabinoid system’s role in depression and anxiety. Objective: This study aimed to review the evidence from animal research and clinical studies on the role of cannabinoid receptors, the major endocannabinoids -anandamide (AEA) and 2-arachidonoylglycerol (2-AG)- and the enzymes related to the synthesis and degradation of these chemicals as putative biomarkers for diagnostic and therapeutic elements of depression and anxiety. Methods: This review included the online search, identification, and analysis of articles (basic and clinical trials) published in English in PubMed linked to the role of cannabinoid receptors, AEA, 2- AG, and the enzymes associated with the synthesis and degradation of these endocannabinoids in depression and anxiety. Results: The neurobiological relevance of the endocannabinoid system offers genetic or pharmacological manipulation of this system as a potential strategy for the diagnostic and clinical management of mood disorders, including depression and anxiety. Conclusion: Although the described approach in this review is promising, no solid evidence is yet available, and along with additional experiments using animal models that mimic human depression and anxiety, clinical trials are needed to explore the role of the endocannabinoid system’s elements as well as the anandamide membrane transporter, none of which have been adequately studied in depression and anxiety.

The behavior of an individual changes from neonate to elderly due to the development of the central nervous system (CNS). One of the important components of the CNS is the cerebrospinal fluid (CSF), which bathes the brain and spinal cord. CSF has changing properties throughout life, including composition and volume imbalance. However, a specific age group that shows prevailing abnormality- corresponding behavior remains unclear. The objective of this article is to explore how such changes reflect on one’s psychological as well as physical processing. Production of CSF could be affected by many factors, including its flow, absorption, volume, and composition. Prenatally, congenital malformations and infections hold the greatest risk of impacting the child’s physical and mental growth. In adolescents, transmission of external substances like alcohol or drugs in the cerebrospinal fluid is known to impact severe mood changes that potentially result in suicide and depression. In the adult working population, the influence of stress levels on CSF composition causes anxiety and sleep disorders. Finally, the reduced production of CSF was found to be associated with memory deficits and Alzheimer’s disease in the aging group. From the collected evidence, it can be observed that CSF played an important role in behavioral changes and may be associated with neurodegenerations. By linking the CSF abnormalities to the clinical symptoms at different stages of life, it may provide additional information in the diagnosis of diseases that are associated with neuropsychological changes.

Background: To date, much evidence has shown the increased interest in natural molecules and traditional herbal medicine as alternative bioactive compounds to fight many inflammatory conditions, both in relation to immunomodulation and in terms of their wound healing potential. Bacopa monnieri is a herb that is used in the Ayurvedic medicine tradition for its anti-inflammatory activity. Objective: In this study, we evaluate the anti-inflammatory and regenerative properties of the Bacopa monnieri extract (BME) in vitro model of neuroinflammation. Methods: Neuronal SH-SY5Y cells were stimulated with TNFα and IFNγ and used to evaluate the effect of BME on cell viability, cytotoxicity, cytokine gene expression, and healing rate. Results: Our results showed that BME protects against the Okadaic acid-induced cytotoxicity in SH-SY5Y cells. Moreover, in TNFα and IFNγ primed cells, BME reduces IL-1β, IL-6, COX-2, and iNOS, mitigates the mechanical trauma injury-induced damage, and accelerates the healing of wounds. Conclusion: This study indicates that BME might become a promising candidate for the treatment of neuroinflammation.

Background: Although distinct disorders, peripheral vascular disease (PVD) and dementia are both associated with a progressive decline in activities of daily living in elderly patients. Objective: This study aimed to compare the functional performance scores between elderly patients with and without dementia and with or without PVD. Methods: Patients with Alzheimer’s disease, vascular dementia, and mixed type dementia and controls were prospectively enrolled. Functional performance scores for basic activities of daily living (BADL) and instrumental activities of daily living (IADL) were evaluated using the Barthel scale and Lawton scale, respectively. PVD was diagnosed using the ankle brachial index (ABI). Results: Controls without PVD were age- and sex-matched with 57 patients with both dementia and PVD and with 69 patients without dementia. The patients with PVD in both groups had lower mean BALD scores. Adjusting for age, clinical dementia rating, and depression, PVD was associated with a higher likelihood of being in the quartiles of lower BADL scores in those with dementia (p=0.020). Adjusting for age, sex, Mini-Mental State Examination (MMSE) score, depression, and comorbidity and drug counts among the patients without dementia, a significant association was observed with PVD and a higher likelihood of being in the quartiles of lower BADL scores (p=0.044). PVD was related to a higher likelihood of being in the quartiles of lower IADL scores in the non-dementia subjects (p=0.001) after adjusting for age, depression, MMSE, education, and comorbidity count. Conclusion: PVD presence determined the poorer status of BADL in demented individuals but not of the level of IADL. It is still unclear whether modifying PVD health risks and undergoing ABI screening may help demented people become more independent.