Dysfunction of ABC Transporters at the Surface of BBB: Potential Implications in Intractable Epilepsy and Applications of Nanotechnology Enabled Drug Delivery

Recent advances in nanotherapy-based treatment of epilepsy

Epilepsy is a complex neurological disorder characterized by recurrent seizures affecting millions of people worldwide. Despite advances in drug therapy, a significant proportion of patients remain resistant to conventional antiepileptic drugs (AEDs) due to challenges such as impermeability of the blood-brain barrier (BBB), multidrug resistance, and multifaceted epileptogenesis. Nanotechnology offers promising strategies to overcome these barriers by enhancing drug delivery across the BBB, improving target specificity and minimizing systemic side effects. This review explores recent advances in different innovative strategies of nanodelivery systems for epilepsy therapy, and we will discuss the design principles, mechanisms of action and therapeutic efficacy of these nanodelivery systems. In addition, we discuss the challenges and limitations that hinder the clinical translation of nanomedicine-based therapies for epilepsy. We emphasize the need for personalized and multidisciplinary approaches as well as the importance of continued research and interdisciplinary collaboration in order to translate these innovative strategies into effective therapies. Ultimately, the use of nanotechnology has the potential to enhance seizure control, reduce the burden of epilepsy, and improve the quality of life of patients affected by this complex neurological disorder. Nanotechnology-based drug delivery systems may usher in a new era of precision medicine for epilepsy treatment.

Research developments in the neurovascular unit and the blood‑brain barrier (Review)

The neurovascular unit (NVU) is composed of neurons, glial cells, brain microvascular endothelial cells (BMECs), pericytes, and the extracellular matrix. The NVU controls the permeability of the blood-brain barrier (BBB) and protects the brain from harmful blood-borne and endogenous and exogenous substances. Among these, neurons transmit signals, astrocytes provide nutrients, microglia regulate inflammation, and BMECs and pericytes strengthen barrier tightness and coverage. These cells, due to their physical structure, anatomical location, or physiological function, maintain the microenvironment required for normal brain function. In this review, the BBB structure and mechanisms are examined to obtain a better understanding of the factors that influence BBB permeability. The findings may aid in safeguarding the BBB and provide potential therapeutic targets for drugs affecting the central nervous system.

The sphingosine-1-phosphate signaling pathway (sphingosine-1-phosphate and its receptor, sphingosine kinase) and epilepsy

Epilepsy is one of the common chronic neurological diseases, affecting more than 70 million people worldwide. The brains of people with epilepsy exhibit a pathological and persistent propensity for recurrent seizures. Epilepsy often coexists with cardiovascular disease, cognitive dysfunction, depression, etc., which seriously affects the patient's quality of life. Although our understanding of epilepsy has advanced, the pathophysiological mechanisms leading to epileptogenesis, drug resistance, and associated comorbidities remain largely unknown. The use of newer antiepileptic drugs has increased, but this has not improved overall outcomes. We need to deeply study the pathogenesis of epilepsy and find drugs that can not only prevent the epileptogenesis and interfere with the process of epileptogenesis but also treat epilepsy comorbidities. Sphingosine-1-phosphate (S1P) is an important lipid molecule. It not only forms the basis of cell membranes but is also an important bioactive mediator. It can not only act as a second messenger in cells to activate downstream signaling pathways but can also exert biological effects by being secreted outside cells and binding to S1P receptors on the cell membrane. Fingolimod (FTY720) is the first S1P receptor modulator developed and approved for the treatment of multiple sclerosis. More and more studies have proven that the S1P signaling pathway is closely related to epilepsy, drug-resistant epilepsy, epilepsy comorbidities, or other epilepsy-causing diseases. However, there is much controversy over the role of certain natural molecules in the pathway and receptor modulators (such as FTY720) in epilepsy. Here, we summarize and analyze the role of the S1P signaling pathway in epilepsy, provide a basis for finding potential therapeutic targets and/or epileptogenic biomarkers, analyze the reasons for these controversies, and put forward our opinions. PLAIN LANGUAGE SUMMARY: This article combines the latest research literature at home and abroad to review the sphingosine 1-phosphate signaling pathway and epileptogenesis, drug-resistant epilepsy, epilepsy comorbidities, other diseases that can cause epilepsy, as well as the sphingosine-1-phosphate signaling pathway regulators and epilepsy, with the expectation of providing a certain theoretical basis for finding potential epilepsy treatment targets and/or epileptogenic biomarkers in the sphingosine-1-phosphate signaling pathway.

Discovery of novel third generation P-glycoprotein inhibitors bearing an azo moiety with MDR-reversing effect

P-glycoprotein (P-gp)-caused multidrug resistance (MDR) is a crucial factor in the cancer chemotherapy failure. Herein, a total of twenty two azo-containing WK-X-34 (WK34, a third generation P-gp inhibitor) derivatives were synthesized as novel P-gp inhibitors. Biological evaluation revealed that compound 7i effectively reversed P-gp-mediated MDR in K562/A02 cells, with a higher reversal fold (RF) value than WK34 (142.79 vs. 64.41). Further investigation indicated that 7i dose-dependently inhibited P-gp function, without affecting its expression. CETSA results illustrated that 7i could obviously improve P-gp stability, suggesting its high affinity with P-gp. Molecular docking analysis revealed that 7i fit well into P-gp's binding pocket, thus displaying potent reversal effect on P-gp-mediated tumor MDR Optical properties evaluation confirmed that azo-containing 7i can undergo reversible changes in the cis and trans configurations under the irradiation of 365 nm and 520 nm wavelength of light. Notably, the configuration change of azo might affect the MDR-reversal potency, and cis-7i has a lower RF value than trans-7i (122.70 vs. 142.79), suggesting that development of photoswitchable P-gp inhibitors might be a novel strategy to reduce the systemic toxicity caused by indiscriminate inhibition of P-gp by traditional inhibitors. Collectively, 7i, as a novel P-gp inhibitor, warranted further investigation.

An Update on the Application of Nano Phytomedicine as an Emerging Therapeutic Tool for Neurodegenerative Diseases

Abstract:

The existence of the blood-brain barrier (BBB), a densely woven network of blood vessels and endothelial cells designed to prevent the infiltration of foreign substances into the brain, the methods employed in developing treatments for neurodegenerative disorders (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Multiple sclerosis, Amyotrophic lateral sclerosis, and others, pose significant challenges and complexities. These illnesses have had a terrible impact on the human population's health. Because early detection of these problems is poor and no good therapy has been established, they have emerged as the biggest lifethreatening healthcare burden worldwide compared to other significant illnesses. Traditional drug delivery techniques do not offer efficient treatment for NDs due to constraints in the BBB design, efflux pumps, and metabolic enzyme expression. Nanotechnology has the potential to significantly enhance ND therapy by utilizing systems that have been bioengineered to engage with living organisms at the cellular range. Compared to traditional techniques, nanotechnological technologies have several potential ways for crossing the BBB and increasing therapeutic efficacy in the brain. The introduction and growth of nanotechnology indicate promising potential for overcoming this issue. Engineered nanoparticles coupled with therapeutic moieties and imaging agents with dimensions ranging from 1-100 nm can improve effectiveness, cellular uptake, selective transport, and drug delivery to the brain due to their changed physicochemical properties. Conjugates of nanoparticles and medicinal plants, or their constituents known as nano phytomedicine, have recently gained importance in developing cutting-edge neuro-therapeutics due to their abundant natural supply, promising targeted delivery to the brain, and lower potential for adverse effects. This study summarizes the common NDs, their prevalence and pathogenesis, and potential herbal nanoformulation for treating NDs.

Emerging Role of ABC Transporters in Glia Cells in Health and Diseases of the Central Nervous System

ATP-binding cassette (ABC) transporters play a crucial role for the efflux of a wide range of substrates across different cellular membranes. In the central nervous system (CNS), ABC transporters have recently gathered significant attention due to their pivotal involvement in brain physiology and neurodegenerative disorders, such as Alzheimer's disease (AD). Glial cells are fundamental for normal CNS function and engage with several ABC transporters in different ways. Here, we specifically highlight ABC transporters involved in the maintenance of brain homeostasis and their implications in its metabolic regulation. We also show new aspects related to ABC transporter function found in less recognized diseases, such as Huntington's disease (HD) and experimental autoimmune encephalomyelitis (EAE), as a model for multiple sclerosis (MS). Understanding both their impact on the physiological regulation of the CNS and their roles in brain diseases holds promise for uncovering new therapeutic options. Further investigations and preclinical studies are warranted to elucidate the complex interplay between glial ABC transporters and physiological brain functions, potentially leading to effective therapeutic interventions also for rare CNS disorders.

Green Synthesis of Silver Nanoparticles and their Potential Applications in Mitigating Cancer

In recent years, the field of nanotechnology has brought about significant advancements that have transformed the landscape of disease diagnosis, prevention, and treatment, particularly in the realm of medical science. Among the various approaches to nanoparticle synthesis, the green synthesis method has garnered increasing attention. Silver nanoparticles (AgNPs) have emerged as particularly noteworthy nanomaterials within the spectrum of metallic nanoparticles employed for biomedical applications. AgNPs possess several key attributes that make them highly valuable in the biomedical field. They are biocompatible, cost-effective, and environmentally friendly, rendering them suitable for various bioengineering and biomedical applications. Notably, AgNPs have found a prominent role in the domain of cancer diagnosis. Research investigations have provided evidence of AgNPs' anticancer activity, which involves mechanisms such as DNA damage, cell cycle arrest, induction of apoptosis, and the regulation of specific cytokine genes. The synthesis of AgNPs primarily involves the reduction of silver ions by reducing agents. Interestingly, natural products and living organisms have proven to be effective sources for the generation of precursor materials used in AgNP synthesis. This comprehensive review aims to summarize the key aspects of AgNPs, including their characterization, properties, and recent advancements in the field of biogenic AgNP synthesis. Furthermore, the review highlights the potential applications of these nanoparticles in combating cancer.

Epilepsy in gliomas: recent insights into risk factors and molecular pathways

PURPOSE OF REVIEW

The purpose of this review is to discuss the molecular pathways governing the development of seizures in glioma patients.

RECENT FINDINGS

The intrinsic epileptogenicity of the neuronal component of glioneuronal and neuronal tumors is the most relevant factor for seizure development. The two major molecular alterations behind epileptogenicity are the rat sarcoma virus (RAS)/mitogen-activated protein kinase / extracellular signal-regulated kinase (MAPK/ERK) and phosphatidylinositol-3-kinase / protein kinase B / mammalian target of rapamycin (P13K/AKT/mTOR) pathways. The BRAFv600E mutation has been shown in experimental models to contribute to epileptogenicity, and its inhibition is effective in controlling both seizures and tumor growth. Regarding circumscribed astrocytic gliomas, either BRAFv600E mutation or mTOR hyperactivation represent targets of treatment. The mechanisms of epileptogenicity of diffuse lower-grade gliomas are different: in addition to enhanced glutamatergic mechanisms, the isocitrate dehydrogenase (IDH) 1/2 mutations and their product D2-hydroxyglutarate (D2HG), which is structurally similar to glutamate, exerts excitatory effects on neurons also dependent on the presence of astrocytes. In preclinical models IDH1/2 inhibitors seem to impact both tumor growth and seizures. Conversely, the molecular factors behind the epileptogenicity of glioblastoma are unknown.

SUMMARY

This review summarizes the current state of molecular knowledge on epileptogenicity in gliomas and highlights the relationships between epileptogenicity and tumor growth.

Synthetic and Natural Bioactive Molecules in Balancing the Crosstalk among Common Signaling Pathways in Alzheimer's Disease: Understanding the Neurotoxic Mechanisms for Therapeutic Intervention

The structure and function of the brain greatly rely on different signaling pathways. The wide variety of biological processes, including neurogenesis, axonal remodeling, the development and maintenance of pre- and postsynaptic terminals, and excitatory synaptic transmission, depends on combined actions of these molecular pathways. From that point of view, it is important to investigate signaling pathways and their crosstalk in order to better understand the formation of toxic proteins during neurodegeneration. With recent discoveries, it is established that the modulation of several pathological events in Alzheimer's disease (AD) due to the mammalian target of rapamycin (mTOR), Wnt signaling, 5'-adenosine monophosphate activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), and sirtuin 1 (Sirt1, silent mating-type information regulator 2 homologue 1) are central to the key findings. These include decreased amyloid formation and inflammation, mitochondrial dynamics control, and enhanced neural stability. This review intends to emphasize the importance of these signaling pathways, which collectively determine the fate of neurons in AD in several ways. This review will also focus on the role of novel synthetic and natural bioactive molecules in balancing the intricate crosstalk among different pathways in order to prolong the longevity of AD patients.

Repurposing approved non-oncology drugs for cancer therapy: a comprehensive review of mechanisms, efficacy, and clinical prospects

Cancer poses a significant global health challenge, with predictions of increasing prevalence in the coming years due to limited prevention, late diagnosis, and inadequate success with current therapies. In addition, the high cost of new anti-cancer drugs creates barriers in meeting the medical needs of cancer patients, especially in developing countries. The lengthy and costly process of developing novel drugs further hinders drug discovery and clinical implementation. Therefore, there has been a growing interest in repurposing approved drugs for other diseases to address the urgent need for effective cancer treatments. The aim of this comprehensive review is to provide an overview of the potential of approved non-oncology drugs as therapeutic options for cancer treatment. These drugs come from various chemotherapeutic classes, including antimalarials, antibiotics, antivirals, anti-inflammatory drugs, and antifungals, and have demonstrated significant antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties. A systematic review of the literature was conducted to identify relevant studies on the repurposing of approved non-oncology drugs for cancer therapy. Various electronic databases, such as PubMed, Scopus, and Google Scholar, were searched using appropriate keywords. Studies focusing on the therapeutic potential, mechanisms of action, efficacy, and clinical prospects of repurposed drugs in cancer treatment were included in the analysis. The review highlights the promising outcomes of repurposing approved non-oncology drugs for cancer therapy. Drugs belonging to different therapeutic classes have demonstrated notable antitumor effects, including inhibiting cell proliferation, promoting apoptosis, modulating the immune response, and suppressing metastasis. These findings suggest the potential of these repurposed drugs as effective therapeutic approaches in cancer treatment. Repurposing approved non-oncology drugs provides a promising strategy for addressing the urgent need for effective and accessible cancer treatments. The diverse classes of repurposed drugs, with their demonstrated antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties, offer new avenues for cancer therapy. Further research and clinical trials are warranted to explore the full potential of these repurposed drugs and optimize their use in treating various cancer types. Repurposing approved drugs can significantly expedite the process of identifying effective treatments and improve patient outcomes in a cost-effective manner.