Epigenetics defines changes in cell function without involving alterations in DNA sequence. Neuroepigenetics bridges neuroscience and epigenetics by regulating gene expression in the nervous system and its impact on brain function. With the increase in research in recent years, it was observed that alterations in the gene expression did not always originate from changes in the genetic sequence, which has led to understanding the role of epigenetics in neurodegenerative diseases (NDDs) including Alzheimer’s disease (AD) and Parkinson’s disease (PD). Epigenetic alterations contribute to the aberrant expression of genes involved in neuroinflammation, protein aggregation, and neuronal death. Natural phytochemicals have shown promise as potential therapeutic agents against NDDs because of their antioxidant, anti-inflammatory, and neuroprotective effects in cellular and animal models. For instance, resveratrol (grapes), curcumin (turmeric), and epigallocatechin gallate (EGCG; green tea) exhibit neuroprotective effects through their influence on DNA methylation patterns, histone acetylation, and non-coding RNA expression profiles. Phytochemicals also aid in slowing disease progression, preserving neuronal function, and enhancing cognitive and motor abilities. The present review focuses on various epigenetic modifications involved in the pathology of NDDs, including AD and PD, gene expression regulation related to epigenetic alterations, and the role of specific polyphenols in influencing epigenetic modifications in AD and PD.

Fabry disease (FD) is caused by a defective α-galactosidase A (α-GAL A) enzyme responsible for breaking down globotriaosylceramide (Gb₃). To develop affordable therapeutics, more effort is needed to obtain insights into the underlying mechanism of FD and understanding human α-GAL A structure and function in related animal models. We adopted C. elegans as a model to elucidate the sequence and 3D structure of its GANA-1 enzyme and compared it to human α-GAL A. We constructed GANA-1 3D structure by homology modelling and validated the quality of the predicted GANA-1 structure, followed by computational docking of human ligands. The GANA-1 protein shared sequence similarities up to 42.1% with the human α-GAL A in silico and had dual active sites. GANA-1 homology modelling showed that 11 out of 13 amino acids in the first active site of GANA-1 protein overlapped with the human α-GAL A active site, indicating the prospect for substrate cross-reaction. Computational molecular docking using human ligands like Gb₃ (first pocket)_, 4-nitrophenyl-α-D-galactopyranoside (second pocket), α-galactose (second pocket), and N-acetyl-D-galactosamine (second pocket) showed negative binding energy. This revealed that the ligands were able to bind within both GANA-1 active sites, mimicking the human α-GAL A and α-NAGA enzymes. We identified human compounds with adequate docking scores, predicting robust interactions with the GANA-1 active site. Our data suggested that the C. elegans GANA-1 enzyme may possess structural and functional similarities to human α-GAL A, including an intrinsic capability to metabolize Gb₃ deposits. Communicated by Ramaswamy H. Sarma

Cisplatin is an effective platinum-based chemotherapeutic agent used to treat a variety of cancers. However, its clinical utility is limited by dose-dependent neurotoxicity, yet no approved neuroprotective strategy currently exists. Our integrated cellular, metabolic, and in vivo approaches unraveled the neuroprotective potential of Areca catechu ethyl acetate extract (AC-EA) against cisplatin-induced neurotoxicity. Importantly, AC-EA did not reduce cisplatin-induced cytotoxicity in A549 lung cancer cells. In HT22 hippocampal neurons, AC-EA restored cell viability, suppressed reactive oxygen species generation, preserved mitochondrial-associated fluorescence, and attenuated phosphorylated histone H2AX (γH2AX)-marked DNA damage. AC-EA was associated with increased pNRF2 expression, consistent with activation of NRF2-dependent antioxidant signaling, suppressed inducible nitric oxide synthase iNOS (inducible nitric oxide synthase )-mediated neuroinflammation, and prevented the depletion of total AKT (protein kinase B) protein. Untargeted metabolomics and Caenorhabditis elegans survival assays were performed for mechanistic and in vivo validation. Metabolomics data showed restoration of several critical amino acids, including L-tyrosine and β-alanine, disrupted by cisplatin. Moreover, C. elegans studies confirmed in vivo activation of antioxidants via the SKN-1/GST-4 (glutathione S-transferase 4) pathway. While AC-EA shows neuroprotective potential, arecoline’s toxicity demands caution. To our knowledge, this is the first study to demonstrate the neuroprotective activity of A. catechu against cisplatin-induced neurotoxicity, laying the foundation for developing plant-derived adjunct therapies for chemotherapy-associated neuropathy.

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