CNS & Neurological Disorders - Drug Targets (Formerly Current Drug Targets - CNS & Neurological Disorders) - Volume 23, Issue 9, 2024

Muscle skeletal striated cells secrete a wide range of proteins called myokines or “exerkines”, which in turn perform autocrine, paracrine, or endocrine functions. For being able to act in the communication between skeletal muscle, adipose tissue, and mainly the brain, exerkines play a prominent role and potential influence on health promotion. Furthermore, we detected in the literature that one of these potential therapeutic substances derived from muscle contraction is a molecule derived from glycolytic metabolism that in the past was largely marginalized, the lactate. Currently, studies are dedicated to examining the target structures for exerkines that may contribute to the maintenance and restoration of mental health. Thus, lactate appears to be recognized as a critical mediator of exercise-related changes and their health benefits, particularly in their role in communication and coordination between organs. It is inferred that the BDNF expression mechanism can be induced by lactate, which in turn derives from the activation of SIRT pathways 1 and 2 and activates the PGC1-α cascade. The behavior of lactate concentration is intensity-dependent, directly related to the type of fast-twitch fibers (type IIb) and the recruitment of these fibers would potentiate the responses in the brain. In this sense, high-intensity exercise would establish itself as an important strategy to be considered. Despite this understanding, there is still much to be done. However, lactate appears to be a highly promising exerkine for future research initiatives and a potential biomarker to reduce illness and promote mental health.

Diabetes is one of the major metabolic disorders of this era. It not only impacts a person's lifestyle but also has a long-term impact on the brain. It has a detrimental effect on a person's health when combined with hypertension and hyperlipidaemia. Several studies have suggested that the incidence of dementia is higher in people with metabolic syndrome. Investigations are underway to determine whether antidiabetic, hypolipidemic, hypercholesteraemic, anti-hypertensive, and other combination medicines can minimize the incidence of cognitive impairment. Some studies have suggested that anti-diabetic drugs like metformin, liraglutide, and dapagliflozin might enhance memory in long-term users. At the same time, other studies indicate that long-term insulin use may cause memory decline. Similarly, drugs like ACEIs, CCBs, fibrates, statins, and various nutraceuticals have been shown to improve cognition via multiple mechanisms. Literature suggests that drugs that can treat metabolic syndrome can also partially reduce the accumulation of beta-amyloid, whereas some studies contradict these findings. We review the past thirty years' of research work and summarize the effects of most commonly used drugs and nutraceuticals for treating metabolic syndrome on memory. Here, we review the effects of antidiabetic, hypolipidemic, anti-hypertensive, and hypercholesteremic, and their combination in learning and memory.

Background: Two classes of medications are used to treat Alzheimer's disease (AD); donepezil, galantamine, and rivastigmine are acetylcholinesterase inhibitors, and memantine is a non-competitive antagonist of the N-methyl-D-aspartate receptor. Although these are typically taken orally, there are transdermal therapeutic systems (TTSs) commercially available for rivastigmine and donepezil. The transdermal route has been preferable for guardians/caregivers due to ease of use, reduced side effects, and improved adherence to therapy. Objective: The study aimed to obtain knowledge of the properties of these drugs and to search for patents relating to the TTS for AD using the Espacenet platform. Methods: The search terms were "rivastigmine AND transdermal AND skin delivery AND Alzheimer’s", changing the drugs "memantine", "donepezil", and "galantamine", between January 2015 and January 2022. Title and abstract were used to choose patents. Results: TTSs present some limit factors in terms of absorption due to skin physiology and the size of the molecules with established limits of percutaneous penetration (molecular mass of 500 g/mol and log P of 5). We found 1, 4, 4, and 2 patents for galantamine, rivastigmine, donepezil, and memantine, respectively. Galantamine TTS seems to be more challenging due to the molecular mass of 287.35 g/mol and logP of 1.8. The permeator of absorption is necessary. Memantine, rivastigmine, and donepezil present logP of 3.28, 2.3, and 4.27 and molecular weights of 179.30, 250.34, and 415.96 g/mol, respectively. Conclusion: TTSs are primarily effective for delivering small molecules. The use of absorption enhancers and irritation mitigators can be necessary to enhance the performance. The development of these technologies is essential for the convenience of patients and caregivers.

Major depressive disorder (MDD) is a complex mood disorder. While much progress has been made in understanding the pathophysiology of MDD, no single mechanism can explain all facets of this disorder. Several studies show that disturbances in biological rhythms can lead to the development of MDD. Indeed, insomnia or hypersomnia are symptoms included in the MDD diagnostic criteria. Clinical studies and meta-analyses showed a strong relationship between MDD and sleep disorders. Sleep disorder and MDD are associated with activation in the hypothalamicpituitary- adrenal (HPA) axis and inflammation. The increase in inflammatory response can activate the kynurenine pathway, decrease serotonin synthesis, and affect other factors involved in the pathophysiology of neuropsychiatric conditions. Moreover, sleep disorders and MDD can change the gut microbiota and alter the microbiota-gut-brain axis. Thus, this review discusses the relationship between MDD, circadian rhythms, and sleep disorders, describing the potential pathophysiological mechanism shared in these conditions. In addition, therapeutic opportunities based on antiinflammatory, antioxidant, HPA axis regulatory, and synapse-modulating actions are raised. For the article search, we used the PubMed database. Both sleep disorders and changes in biological rhythms have a bidirectional relationship with MDD. Although some pathophysiological mechanisms, including inflammation, changes in the gut microbiota, and decreased neuroplasticity, may be involved in the relationship between sleep, circadian rhythms, and MDD, other mechanisms are not yet well understood. Therapeutic opportunities based on anti-inflammatory, antioxidant, HPA regulatory axis, and synapse modulating actions appear to be promising targets in preventing MDD, circadian rhythm disturbances, and sleep disorders.

Astrocytes are glial cells that perform several fundamental physiological functions within the brain. They can control neuronal activity and levels of ions and neurotransmitters, and release several factors that modulate the brain environment. Over the past few decades, our knowledge of astrocytes and their functions has rapidly evolved. Neurodegenerative diseases are characterized by selective degeneration of neurons, increased glial activation, and glial dysfunction. Given the significant role played by astrocytes, there is growing interest in their potential therapeutic role. However, defining their contribution to neurodegeneration is more complex than was previously thought. This review summarizes the main functions of astrocytes and their involvement in neurodegenerative diseases, highlighting their neurotoxic and neuroprotective ability.

Epilepsy is a chronic neurological condition characterized by unprovoked, recurrent seizures. There are several types of epilepsy, and the cause of the condition can vary. Some cases of epilepsy have a genetic component, while others may be caused by brain injuries, infections, or other underlying conditions. Treatment for epilepsy typically involves anti-seizure medications (ASMs), although different approaches, such as surgery or a special diet, may be considered in specific cases. The treatment aims to effectively manage and potentially eliminate seizures while minimizing any accompanying side effects. Many different ASMs are available, and the choice of medication depends on several factors, including the type of seizures, the patient's age, general health, and potential drug interactions. For the treatment of epilepsy, there have been significant advancements in recent decades, which have led to the approval of many different ASMs. Newer ASMs offer a broader range of mechanisms of action, improved tolerability profiles, and reduced drug interactions compared to older drugs. This review aims to discuss the pharmacological characteristics, clinical applications, effectiveness, and safety of ASMs, with a particular emphasis on various age groups, especially children. Moreover, this review seeks to provide a comprehensive understanding of ASM therapy for epilepsy management, assisting physicians in selecting suitable ASMs for their patients.

Neurodegenerative diseases are caused by the loss of neurons and/or their myelin sheaths, which deteriorate over time and become dysfunctional. Alzheimer's disease, Parkinson's disease, and multiple sclerosis are among the most prominent neurodegenerative diseases that affect millions of older adults worldwide. Despite extensive research over several decades, controversies still surround the etiology of neurodegenerative diseases, and many of them remain incurable. Meanwhile, an increasing number of new mechanistic studies related to the microbiota-gut-brain axis have emerged, among which the relationship between the function of the intestinal barrier and neurodegenerative diseases has received widespread attention. As one of the first lines of defense between the body and the external environment, the impaired function of the intestinal barrier is closely related to the development of neurodegenerative pathologies. Among them, the microbiota-gut-brain axis disorder characterized by intestinal barrier disruption mainly includes impaired function of the intestinal microbial barrier, chemical barrier, mechanical barrier, and immune barrier. This review focuses on the structure and molecular mechanisms of the various layers of the intestinal barrier as well as their relationship with neurodegenerative lesions. In recent years, intestinal barrier repair therapies have provided new ideas for the studied disease treatment modalities. We believe that a better understanding of the role of the intestinal barrier in neurodegenerative diseases would provide new insights for the development of viable therapeutic strategies for patients.

Background: Alzheimer’s disease is a neurodegenerative disorder characterized by severe cognitive, behavioral, and psychological symptoms, such as dementia, cognitive decline, apathy, and depression. There are no accurate methods to diagnose the disease or proper therapeutic interventions to treat AD. Therefore, there is a need for novel diagnostic methods and markers to identify AD efficiently before its onset. Recently, there has been a rise in the use of imaging techniques like Magnetic Resonance Imaging (MRI) and functional Magnetic Resonance Imaging (fMRI) as diagnostic approaches in detecting the structural and functional changes in the brain, which help in the early and accurate diagnosis of AD. In addition, these changes in the brain have been reported to be affected by variations in genes involved in different pathways involved in the pathophysiology of AD. Methodology: A literature review was carried out to identify studies that reported the association of genetic variants with structural and functional changes in the brain in AD patients. Databases like PubMed, Google Scholar, and Web of Science were accessed to retrieve relevant studies. Keywords like ‘fMRI’, ‘Alzheimer’s’, ‘SNP’, and ‘imaging’ were used, and the studies were screened using different inclusion and exclusion criteria. Results: 15 studies that found an association of genetic variations with structural and functional changes in the brain were retrieved from the literature. Based on this, 33 genes were identified to play a role in the development of disease. These genes were mainly involved in neurogenesis, cell proliferation, neural differentiation, inflammation and apoptosis. Few genes like FAS, TOM40, APOE, TRIB3 and SIRT1 were found to have a high association with AD. In addition, other genes that could be potential candidates were also identified. Conclusion: Imaging genetics is a powerful tool in diagnosing and predicting AD and has the potential to identify genetic biomarkers and endophenotypes associated with the development of the disorder.

Background: Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) has been associated with severe morbidity and high mortality. It has been demonstrated that early intervention is of paramount importance. The aim of our study is to evaluate the functional outcome and the overall survival of early microsurgically treated patients. Material and Methods: Poor-grade aSAH patients admitted at our institution over fifteen years (January 2008 - December 2022) were included in our retrospective study. All participants underwent brain Computed Tomography Angiography (CTA). Fisher scale was used to assess the severity of hemorrhage. All our study participants underwent microsurgical clipping, and their functional outcome was assessed with the Glasgow Outcome Scale (GOS). We used logistic regression analysis to identify any parameters associated with a favorable outcome at 12 months. Cox proportional hazard analysis was also performed, identifying factors affecting the length of survival. Results: Our study included 39 patients with a mean age of 54 years. Thirty of our participants (76.9%) were Hunt and Hess grade V, while the vast majority (94.9%) were Fisher grade 4. The observed six-month mortality rate was 48.6%. The mean follow-up time was 18.6 months. The functional outcome at six months was favorable in 6 patients (16.2%), increased to 23.5% at 12 months. Our data analysis showed that the age, as well as the employment of temporary clipping during surgery, affected the overall outcome. Conclusion: Management of poor-grade aSAH patients has been dramatically changed. Microsurgical clipping provides promising results in carefully selected younger patients.

Aim: We aimed to investigate the mechanisms involved in the neurotoxic effects of NDGA on differentiated and undifferentiated human neuroblastoma cells (MSN), assessing cell viability, changes in the actin cytoskeleton, cell migration and the expression of the 5-LOX enzyme and the inhibitor of cell cycle progression p21^WAF1/CIP1. Background: High expression and activity of the lipoxygenase enzyme (LOX) have been detected in several tumors, including neuroblastoma samples, suggesting the use of LOX inhibitors as potential therapy molecules. Among these, the natural compound nordihydroguaiaretic acid (NDGA) has been extensively tested as an antiproliferative drug against diverse types of cancer cells. Objective: In this study, we analyzed the toxic effect of NDGA on neuroblastoma cells at a dose that did not affect cell survival when they differentiated to a neuron-like phenotype and the potential mechanisms involved in the anticancer properties. Methods: We exposed human neuroblastoma cells (MSN) to different concentrations of NDGA before and after a differentiation protocol with retinoic acid and nerve growth factor and analyzed cell viability, cell migration, actin cytoskeleton morphology and the levels of the cell cycle inhibitor p21^WAF1/CIP1 and 5-LOX. Results: We found that differentiated human neuroblastoma cells are more resistant to NDGA than undifferentiated cells. The toxic effects of NDGA were accompanied by reduced cell migration, changes in actin cytoskeleton morphology, induction of p21^WAF1/CIP1 and decreased levels of the 5-LOX enzyme. Conclusion: This study provides new evidence regarding the potential use of NDGA to induce cell death in human neuroblastoma.