👤 Michael Aschner

Phthalates are ubiquitous environmental contaminants and endocrine-disrupting chemicals used as plasticizers in consumer products, medical devices, and industrial materials. Evidence from in vitro experiments, animal models, and epidemiological studies suggests that phthalate exposure, particularly to di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and benzyl butyl phthalate (BBP), may induce neurotoxicity through multiple interconnected mechanisms. The developing brain is especially vulnerable, with prenatal and early-life exposures linked to cognitive deficits, behavioral abnormalities, and neurodevelopmental disorders. Conventional therapeutic options remain limited, highlighting the need for effective neuroprotective strategies. Natural bioactive compounds such as polyphenols, flavonoids, carotenoids, and other phytochemicals have been investigated as potential neuroprotective candidates in preclinical models owing to their multi-target mechanisms (e.g., antioxidant, anti-inflammatory, and neurotrophic actions), potent antioxidant capacity, and regulation of cellular signaling pathways. Preclinical studies demonstrate that lycopene, ferulic acid, coenzyme Q10, omega-3 fatty acids, vanillic acid, and Moringa oleifera extracts attenuate phthalate-induced neurotoxicity by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway, suppressing nuclear factor-kappa B (NF-κB)-mediated inflammation, modulating MAPK/ERK and PI3K/Akt signaling, and restoring brain-derived neurotrophic factor (BDNF)/TrkB support. Despite these promising findings, challenges persist, including poor bioavailability, lack of standardized dosing, and limited human clinical trials. A structured review of experimental and epidemiological studies was conducted using predefined inclusion criteria. This review integrates evidence across in vitro, in vivo, and human studies to identify key mechanisms of phthalate-induced neurotoxicity, including oxidative stress, neuroinflammation, endocrine disruption, epigenetic dysregulation, and impaired neuroplasticity, and evaluates pathway-specific neuroprotective actions of bioactive compounds while highlighting critical translational gaps. Show less

Depression is a widespread neuropsychiatric disorder that significantly impacts emotional and cognitive function. Antidepressant medications are frequently accompanied by various adverse effects. C-phycocyanin has been previously shown to exert potent anti-inflammatory, and neuroprotective properties. Therefore, this study evaluated the therapeutic effects of C-phycocyanin against anxiety and depressive-like behaviors, and memory dysfunction in an animal model of chronic unpredictable mild stress (CUMS)-induced depression and explored the underlying mechanisms. Rats were daily exposed for six weeks to CUMS, during which phycocyanin (100 mg/kg, orally) was administered in the final three weeks of the study. Following the assessment of anxiety/ depressive-like behaviors, and memory dysfunction by the open field test (OFT), tail suspension test (TST), elevated plus maze (EPM), and passive avoidance test (PAT), rats were euthanized by decapitation. Then, hippocampal TNF-α and IL-1β concentrations, and hippocampal protein expressions (Iba-1, CD86, NF-κβ, CREB, and BDNF) were determined by an ELISA assay, and western blots, respectively. C-phycocyanin significantly decreased immobility time in OFT and TST, increased open arm time in EPM, and step-through latency time in PAT. Furthermore, C-phycocyanin suppressed CUMS-induced the M1 microglia polarization and neuroinflammation by reducing hippocampal TNF-α and IL-1β concentrations, and the protein expression of Iba-1, CD86, and NF-κβ in the hippocampus of CUMS-exposed rats. It also increased the hippocampal protein expression of CREB and BDNF. C-phycocyanin improved CUMS-induced anxiety and depressive-like behaviors, and memory dysfunction, which could be explained, at least in part, by inhibition of M1 microglial polarization and neuroinflammation, and enhancement of CREB/BDNF signaling. Show less

Manganese and iron are essential trace elements involved in critical neuronal processes; however, excessive exposure to these metals is a significant risk factor for Alzheimer's disease (AD). While most previous studies have focused on single-metal neurotoxicity, the mechanisms underlying combined manganese and iron exposure remain unclear. In this study, we investigated the effects of manganese and iron exposure, both individually and in combination, on tau hyperphosphorylation, β-amyloid (Aβ) accumulation (particularly Aβ Show less

Neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) are characterized by progressive neuronal loss and chronic neuroinflammation. Increasing evidence highlights the interleukin-12 (IL-12) cytokine family-including IL-12, IL-23, IL-27, and IL-35-as central regulators of immune responses in the central nervous system (CNS). IL-12 and IL-23 predominantly promote pro-inflammatory pathways by driving Th1/Th17 activity, microglial activation, and neurotoxicity, whereas IL-27 and IL-35 exert anti-inflammatory and neuroprotective effects through IL-10 induction and expansion of regulatory immune subsets. This review synthesizes disease-specific expression patterns and experimental findings, underscoring the dual pathogenic and protective roles of these cytokines. Therapeutic strategies targeting IL-12 family signaling have shown promise in preclinical and clinical contexts. In AD, blockade of IL-12/IL-23 reduced amyloid burden and improved cognition, while agents such as tadalafil and bergapten enhanced IL-27-mediated neuroprotection via PI3K/Akt, Wnt/β-catenin, and cGMP/PKG pathways. In MS, approaches including p40 blockade (ustekinumab, ABT-874), interferon-β therapy, hematopoietic stem cell transplantation, and B-cell depletion (ocrelizumab) variably suppressed IL-12/IL-23 and augmented IL-27/IL-35, influencing relapse rates and progression. Natural compounds such as curcumin, berberine, and vitamin D further highlight metabolic and dietary opportunities for cytokine modulation. In PD, combinatorial regimens combining herbal formulations with anti-inflammatory agents dampened IL-12-driven macrophage activation and supported dopaminergic neuron survival. Taken together, IL-12 family cytokines emerge as both biomarkers and therapeutic targets in NDs. However, context-dependent activity, blood-brain barrier constraints, and incomplete understanding-particularly of IL-35-pose translational challenges warranting further investigation. Show less

Aluminum (Al) is known to induce neurotoxic effects, potentially contributing to Alzheimer's disease (AD) pathogenesis. Recent studies suggest that epigenetic modification may contribute to Al neurotoxicity, although the mechanisms are still debatable. Therefore, the objective of the present study was to summarize existing data on the involvement of epigenetic mechanisms in Al-induced neurotoxicity, especially AD-type pathology. Existing data demonstrate that Al exposure induces disruption in DNA methylation, histone modifications, and non-coding RNA expression in brains. Alterations in DNA methylation following Al exposure were shown to be mediated by changes in expression and activity of DNA methyltransferases (DNMTs) and ten-eleven translocation proteins (TETs). Al exposure was shown to reduce histone acetylation by up-regulating expression of histone deacetylases (HDACs) and impair histone methylation, ultimately contributing to down-regulation of brain-derived neurotrophic factor (BDNF) expression and activation of nuclear factor κB (NF-κB) signaling. Neurotoxic effects of Al exposure were also associated with aberrant expression of non-coding RNAs, especially microRNAs (miR). Al-induced patterns of miR expression were involved in development of AD-type pathology by increasing amyloid β (Aβ) production through up-regulation of Aβ precursor protein (APP) and β secretase (BACE1) expression (down-regulation of miR-29a/b, miR-101, miR-124, and Let-7c expression), increasing in neuroinflammation through NF-κB signaling (up-regulation of miR-9, miR-125b, miR-128, and 146a), as well as modulating other signaling pathways. Furthermore, reduced global DNA methylation, altered histone modification, and aberrant miRNA expression were associated with cognitive decline in Al-exposed subjects. However, further studies are required to evaluate the contribution of epigenetic mechanisms to Al-induced neurotoxicity and/or AD development. Show less

Clearance of accumulated protein aggregates is one of the functions of autophagy. Recently, a clearer understanding of non-coding RNAs (ncRNAs) functions documented that ncRNAs have important roles in several biological processes associated with the development and progression of neurodegenerative disorders. Subtypes of ncRNA, including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA), are commonly dysregulated in neurodegenerative disorders such as Alzheimer and Parkinson diseases. Dysregulation of these non-coding RNAs has been associated with inhibition or stimulation of autophagy. Decreased miR-124 led to decreased/increased autophagy in experimental model of Alzheimer and Parkinson diseases. Increased BACE1-AS showed enhanced autophagy in Alzheimer disease by targeting miR-214-3p, Beclin-1, LC3-I/LC3-II, p62, and ATG5. A significant increase in NEAT1led to stimulated autophagy in experimental model of PD by targeting PINK1, LC3-I, LC3-II, p62 and miR-374c-5p. In addition, increased BDNF-AS and SNHG1 decreased autophagy in MPTP-induced PD by targeting miR-125b-5p and miR-221/222, respectively. The upregulation of circNF1-419 and circSAMD4A resulted in an increased autophagy by regulating Dynamin-1 and miR-29c 3p, respectively. A detailed discussion of miRNAs, circRNAs, and lncRNAs in relation to their autophagy-related signaling pathways is presented in this study. Show less