Molecular and Genetic Mechanisms of Neurotoxicity During Anti-seizure Medications Use.

Abstract: Epilepsy is a multifactorial pathology that has allowed the development of various drugs aiming to combat it. This effort was formally initiated in the 1940s when phenytoin began to be used. It eventually turned out to be a drug with great anticonvulsant efficacy. At present, several potentially good new generation anti-seizure medications (ASMs) have been developed. Most of them present more tolerability and less toxic effects. However, they continue to have adverse effects at different levels. In addition, some seizures are difficult to treat with ASMs, representing 30% of the total cases of people who suffer from epilepsy. This review aims to explore the genetic and molecular mechanisms of ASMs neurotoxicity, proposing the study of damage caused by epileptic seizures, in addition to the deterioration generated by anti-seizure drug administration within the central nervous system. It is beyond question that there is a need to develop drugs that lower the lower the risk of secondary and toxic effects of ASMs. Simultaneously, we must find strategies that produce fewer harmful interactions and more health benefits when taking anti-seizure drugs.

Exposure to Ozone Downregulates Bcl-2 and Increases Executing Caspases-3 and -8 in the Hippocampus, Frontal Cortex, and Cerebellum of Rats.

Introduction Ozone (O3) is one of the most prevalent atmospheric pollutants, arising from a photochemical reaction between volatile organic compounds (VOC), nitrogen oxides (NOx), and sunlight. O3 triggers oxidative stress, resulting in lipid oxidation, inflammation, alterations in metabolic and cellular signaling, and potentially initiating cell death in vulnerable brain regions. Inflammation and oxidative stress are recognized for their ability to induce cell death, primarily through the apoptosis pathway, involving various proteins that participate in this process via two pathways: intrinsic and extrinsic. Objective This study aims to identify the expression of pro-apoptotic proteins and Bcl-2 in the frontal cortex, cerebellum, and hippocampus of rats exposed to O3 acutely. Methods Two groups of 20 Wistar rodents (250-300 g) were established. The control group (n=10) was exposed to unrestricted polluted air for 12 hours, while the experimental group (n=10) was exposed to 1 ppm of O3. After exposure, the animals were sacrificed for immunofluorescence and Western blot analysis. Using a t-test, the arbitrary units of pro-apoptotic proteins and Bcl-2 were compared between the two groups. Results Significant increases in caspase-8 and caspase-3 activation were found in the O3-exposed group compared to the control group, specifically in the frontal cortex, cerebellum, and hippocampus. Additionally, notable changes in Bcl-2 expression were observed in these brain regions. The TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay further indicated significant differences in immunopositivity between the groups in the same areas. However, intrinsic apoptotic proteins such as Bax, VDAC1, and cytochrome-c did not show significant differences between the groups within these structures. Western blot analyses aligned with the immunofluorescence results, showing statistically significant concentrations of caspase-8 in the cerebellum, caspase-3 in the hippocampus, and Bcl-2 in the frontal cortex in the O3 exposed group. Conversely, proteins like Bax, cytochrome-c, and VDAC1 did not exhibit significant differences in all analyzed structures. Conclusions This study demonstrates that acute exposure to 1 ppm of ozone can trigger neuronal apoptosis in the frontal cortex, hippocampus, and cerebellum of rats, primarily through the activation of the extrinsic apoptosis pathway via caspase-8 and caspase-3. Additionally, it causes a reduction in Bcl-2 expression, an essential antiapoptotic protein. Despite not observing the activation of intrinsic pathway proteins like BAX, VDAC, or cytochrome-c, the study suggests that chronic O3 exposure might promote cell death by activating this pathway, requiring further long-term research.

A Deep Dive in the Involvement of the Cerebellum in Epilepsy: A Neuroanatomical and Cellular Approach.

OBJECTIVE: The purpose of this article is to describe the state-of-art of neuroanatomical and cellular aspects of the cerebellum in epilepsy. BACKGROUND: Over the years, cerebellum epileptogenesis has been widely studied. There is growing evidence linking the cerebellum with this pathology by several other structures involved: mainly the limbic system, thalamus, cerebral cortex, red nucleus, and reticular formation. As a result, these anatomical and cellular changes in the cerebellum might trigger the genesis and propagation of seizures. DISCUSSION: We herewith outline the cerebellum's deep nuclei physiological pathways, responsible for seizure spread via ion channels and neurotransmitter dysfunction. Additionally, we describe the shifts in seizures produced after cell death, gene expression, and protein interaction with their respective molecular and anatomical pathways. CONCLUSION: Finally, we highlight the role played by the cerebellum in seizure propagation to the brain and how it can be counteracted in some subtypes of drug-resistant epilepsy.

Molecular and Genetic Mechanisms of Neurotoxicity During Anti-seizure Medications Use

ABSTRACT Epilepsy is a multifactorial pathology that has allowed the development of various drugs aiming to combat it. This effort was formally initiated in the 1940s when phenytoin began to be used. It eventually turned out to be a drug with great anticonvulsant efficacy. At present, several potentially good new generation anti-seizure medications (ASMs) have been developed. Most of them present more tolerability and less toxic effects. However, they continue to have adverse effects at different levels. In addition, some seizures are difficult to treat with ASMs, representing 30% of the total cases of people who suffer from epilepsy. This review aims to explore the genetic and molecular mechanisms of ASMs neurotoxicity, proposing the study of damage caused by epileptic seizures, in addition to the deterioration generated by anti-seizure drug administration within the central nervous system. It is beyond question that there is a need to develop drugs that lower the lower the risk of secondary and toxic effects of ASMs. Simultaneously, we must find strategies that produce fewer harmful interactions and more health benefits when taking anti-seizure drugs.