Biology and Life Sciences

Abstract: Background/Objectives: Ultraviolet C (UVC) disinfection devices have been widely adopted since the COVID-19 pandemic. Short UVC exposure reportedly exerts greater cytotoxicity against cancer cells than normal cells. This study examined whether this differential sensitivity is associated with rapid, cancer-cell-specific changes in intracellular metabolites. Methods: Two malignant/non-malignant cell pairs were examined: COLO 679 melanoma cells and human dermal fibroblasts (HDFa), and Ca9-22 gingival carcinoma cells and human gingival fibroblasts (HGF). Viability was assessed using the MTT assay, and metabolites extracted immediately after irradiation were quantified by capillary electrophoresis–time-of-flight mass spectrometry. Results: UVC caused a time-dependent reduction in viability that reached a plateau after 48 h. Sensitivity decreased in the following order: cancer cells, young normal cells, and normal cells at advanced population doubling levels. Baseline metabolic profiles differed markedly between malignant and non-malignant cells. UVC significantly altered 27 of 139 metabolites in Ca9-22 cells, 56 of 142 in HGF, 7 of 136 in COLO 679, and 18 of 129 in HDFa. All four cell types accumulated the pentose phosphate pathway intermediates 6-phosphogluconate and ribulose 5-phosphate, whereas the glycolytic intermediates fructose 6-phosphate, 3-phosphoglycerate, and phosphoenolpyruvate decreased. Succinate decreased in both gingiva-derived cell types. Glutathione, NAD-related metabolites, and ATP showed no marked immediate changes. Conclusions: No cancer-cell-specific metabolic response was identified. Instead, UVC induced a common pattern characterized by the accumulation of pentose phosphate pathway intermediates and the depletion of glycolytic intermediates. This pattern may reflect an early response supporting nucleotide synthesis for DNA repair that is subsequently disrupted, potentially in association with mitochondrial dysfunction.

Abstract: Microplastics (MP), including tire wear particles, are increasingly detected in aquatic environments where they may interact with co-occurring contaminants such as heavy metals (HM). However, the influence of metal loading on MP–plant interactions and subsequent biological responses remains poorly understood. This study investigated how heavy metal loading modifies the behavior of mixed MP and their effects on two aquatic macrophytes, Lemna minor L. and Spirodela polyrhiza (L.) Schleid. Mixtures of polyethylene, polypropylene, polystyrene, and tire rubber particles were tested in both virgin and HM-loaded forms, with the latter preincubated with Cu, Zn and Pb. Duckweed species were exposed to MP concentrations ranging from 20 to 10,000 particles/L for seven days. HM-loaded MP released Cu and Pb into the plant-free exposure medium, whereas Cu release was also detected from the nominally virgin MP mixture. Cu accumulation occurred in both duckweed species, indicating transfer of MP-associated metals to aquatic plants. MP adsorption increased with exposure concentration and was higher in L. minor than in S. polyrhiza, with polypropylene showing the strongest association with plant surfaces. Metal loading reduced MP adsorption at intermediate concentrations, indicating that adsorbed metals can influence MP–plant interactions in a polymer- and concentration-dependent manner. Although MP exposure did not significantly affect growth, chlorophyll a content and antioxidant/detoxification enzyme activities were altered, particularly in L. minor. Overall, the results demonstrate that heavy metal loading modifies microplastic behavior and influences metal availability and sublethal responses in aquatic plants.

Abstract: Microplastics (MPs) are ubiquitous marine pollutants that pose increasing ecological risks, yet their effects on intestinal physiology and gut microbial homeostasis during the juvenile developmental stages of Tachypleus tridentatus remain unclear. In this study, fifth- and sixth-instar juveniles of T. tridentatus were exposed to environmentally relevant concentrations of 6.0 μm polystyrene microplastics (PS-MPs; 0, 10², and 10⁴ particles/L) for 7 and 21 days to investigate intestinal toxicity and its underlying mechanisms. Intestinal accumulation, oxidative stress, innate immune responses, and gut microbiota were comprehensively evaluated. PS-MPs exposure induced dose- and time-dependent alterations in superoxide dismutase, catalase, malondialdehyde, and lysozyme, indicating excessive oxidative stress, impaired antioxidant defense, and compromised innate immunity. Fifth-instar juveniles exhibited stronger oxidative stress and immune responses than sixth-instar individuals, suggesting higher susceptibility during earlier developmental stages. Gut microbiota analysis revealed pronounced dysbiosis, characterized by a reduced relative abundance of Firmicutes, enrichment of Proteobacteria, depletion of beneficial taxa (e.g., Lactococcus), and increased abundance of opportunistic bacteria, including Pseudomonas and members of Enterobacteriaceae. These physiological and microbial alterations collectively suggest that environmentally relevant PS-MPs impair intestinal homeostasis in juvenile T. tridentatus by inducing oxidative imbalance, modifying innate immune responses, and reshaping gut microbial communities, with clear instar- and exposure time-dependent effects. These findings highlighting the importance of developmental stages in ecological risk assessment for benthic arthropods.

Abstract: Epidemiological studies have identified the developing brain as a target of concern for polychlorinated biphenyls (PCBs). In animal models, behavioral deficits caused by developmental exposure to PCBs have been associated with altered patterns of dendritic arborization in functionally relevant brain regions. In vitro studies revealed that PCB 95 promoted dendritic growth in primary rat hippocampal neuron-glia co-cultures via ryanodine receptor 1 (RYR1)-dependent Ca²⁺ signaling. However, it is not yet known whether RYR1 dysregulation contributes to disruption of dendritic morphogenesis in the intact developing brain, or whether PCB 95 affects translationally relevant behavioral endpoints in juvenile animals. To address these data gaps, we assessed Morris water maze (MWM) performance and dendritic arborization of hippocampal CA1 pyramidal neurons in C57BL/6 mice heterozygous for the human R163C-RYR1 gain-of-function mutation (HET) and congenic wild-type (WT) littermates exposed to vehicle or PCB 95 at 0.1, 1.0, or 6.0 mg/kg/d in the dam’s diet from conception through weaning. MWM performance was not altered in HET vehicle controls relative to WT vehicle controls; however, compared to genotype-matched vehicle controls, spatial learning was impaired in WT and HET male and female weanlings in the 1.0 mg/kg/d PCB 95 dose group and WT males in the 6.0 mg/kg/d PCB 95 dose group. Spatial memory was altered only in WT females exposed to 1.0 or 6.0 mg/kg/d PCB 95. Sholl analyses of Golgi-stained hippocampal neurons in male and female WT and HET weanling from the 1.0 mg/kg/d PCB 95 and vehicle groups indicated that relative to WT vehicle controls, basal dendritic arborization was significantly increased in in HET vehicle controls and in PCB 95-exposed WT weanlings; however, PCB 95 did not alter basal dendritic growth in HET weanlings relative to genotype-matched vehicle controls. PCB 95 significantly reduced training-induced dendritic arborization in WT but not HET weanlings. Measurement of tritiated ryanodine ([³H]Ry) binding in cortical tissue from these same animals revealed interactions between genotype, PCB 95 exposure and dose altered [³H]Ry binding relative to WT vehicle controls. Quantitative analyses confirmed a dose-dependent increase in PCB tissue burden that was not significantly altered by genotype, MWM training, or sex. Serum levels of progesterone, estradiol, cortisol and thyroid hormone (TH), and brain transcript levels of TH-responsive genes were not significantly altered by genotype or PCB 95 dose. These data demonstrate that PCB 95 caused behavioral deficits coincident with altered patterns of basal and training-induced dendritic arborization. Furthermore, behavioral and dendritic responses to PCB 95 were altered by expression of the human R163C-RYR1 gain-of-function mutation, supporting a role for RYR-dependent mechanisms in PCB 95 DNT in vivo.

Abstract: Chirantodendron pentadactylon L., known in Mexico City as “flor de manita”, is a plant native to Mexico that is used traditionally in gastrointestinal, cardiovascular, and neurological diseases. This study looked at its potential toxicity using computer models and animal testing. Many people believe that “natural” means “safe,” but this can lead to unregulated use and health risks because some compounds can be toxic. Using computer-based toxicology, researchers analyzed thirty-eight compounds from the flowers of Ch. pentadactylon. They found that 65.8% of the compounds were potentially harmful to the liver, 63.1% mutagenic, 63.5% carcinogenic, 7.8% posed risks to the heart, and 15.7% could affect reproduction. However, 84.2% of these compounds had predicted lethal doses (LD₅₀) greater than 1000 mg/kg. In tests on CD1 mice using water extracts, there were no signs of toxicity or death at doses up to 5000 mg/kg. The Integrative Toxicity Prediction Model suggests that the dried water extract (AEDF) is safe, with a protection value of 0.5332 compared to a toxicity value of 0.0395. This resulted in a safety-to-risk ratio of 13.5. A further analysis estimated a 38.45% chance of toxicity and a 61.55% chance of non-toxicity, placing the extract in a low-risk category for toxicity. These findings suggest that predicting toxicity from single ingredients might overstate the dangers of using combined plant materials. The safety of this plant appears to come from the high levels of beneficial compounds that protect against toxic effects. More long-term studies are needed to check for any cumulative risks.

Abstract: Background: Maternal smoking during pregnancy remains a significant public health concern. The molecular mechanisms underlying smoking-induced maternal-fetal impact remain incompletely understood. The objective of this study is to identify adductomic signatures of oxidant stress in cord blood associated with tobacco exposure during pregnancy. Methods: Through a prospective longitudinal cohort of mother-infant dyads enrolled at a single birth center (Chicago, IL) from 2008-2021, we linked prenatal maternal smoking status data to an existent database of 105 addition products (adducts) measured in cord blood plasma. Principal component analysis (PCA) and volcano plot analysis identified differential adduct profiles according to maternal smoking status using PERMANOVA (p≤0.05). Results: Among 158 births included in the analysis, 6 women reported currently smoking, 26 were former smokers, and 126 identified as never smokers. PCA revealed significant separation between current smokers and both other groups (p≤0.002), with R² effect sizes of 0.026 for current vs never smokers and 0.115 for current vs former smokers. Among 56 known (annotated) adducts of oxidant stress, 33 were significantly upregu-lated in current versus never smokers, and 34 were upregulated in current versus former smokers. Maternal chronic hypertension, but not preeclampsia or other covariates, was associated with current smoking status (P=0.001). Conclusions: Maternal smoking during pregnancy is associated with distinct cord blood adductomic signatures of oxidant stress. The persistence of these changes in current but not former smokers suggests potential reversibility upon smoking cessation.

Abstract:

The GARDskin DR assay is a non-animal method that predicts dermal sensitization potency of discrete compounds. This comparative analysis evaluates outputs from a component-based prediction model (CP), GARDskin DR, and historical local lymph node assays (LLNA) exploring the applicability of CP and GARDskin DR for evaluating the sensitization potencies of essential oils. Eight well-studied essential oils were selected including cedarwood, cinnamon bark, clove bud, geranium, lavender, lemongrass, spearmint, and tea tree oils. Each underwent GC-MS and GARDskin DR analysis. CP model outputs, GARDskin DR and reference LLNA data were compared using standard statistical methods. Spearman’s test shows significant correlation between NESIL_CP vs. NESIL_GARD (0.881, p = 0.007) and NESIL_LLNA (0.929, p = 0.007) but not between NESIL_GARD vs. NESIL_LLNA (0.607, p = 0.17). Friedman’s test detected a significant difference among methods (χ²(2) = 7.71, p = 0.021), with post hoc tests showing relatively greater NESIL_CP values. Kendall’s W shows overall strong statistical concordance between methods (0.857, p = 0.017). NESIL_GARD and NESIL_CP generally align with NESIL_LLNA for the essential oils tested, although the CP method yields greater values. With the limited number of materials tested, results should be interpreted descriptively but show promise for GARDskin DR and CP for evaluating dermal sensitization potency of essential oils.

Abstract: Natural products represent an important source of bioactive compounds with therapeutic potential in the fields of thrombotic and oxidative stress related disorders. The antiplatelet and hepatoprotective activity of ethanolic leaf extract of Ocimum sanctum L. was studied. Collagen-induced human platelet activation (CIHPA) and CCl₄-induced hepatotoxicity were used in rats as models to assess the (EEOSL) activity. EEOSL (1-10 mg/mL) showed to significantly and dose-dependently inhibit collagen-induced platelet aggregation. The extract also inhibited P-selectin expression, ATP release and intracellular Ca²⁺ mobilization, suggesting inhibition of major pathways in platelet activation. To understand the mechanisms, molecular docking was carried out with signaling molecules of platelets such as GPVI, SYK, PLCγ2, P2RY12, and PI3Kβ. Some phytoconstituents have good binding affinities, apigenin having the highest binding affinity to PI3Kβ (−8.01 kcal/mol), and binding was further validated by molecular dynamics simulations showing the formation of stable complexes. Intravenous injection of CCl₄ significantly increased the serum hepatic markers (SGOT, SGPT, LDH and SALP); the EEOSL treatment significantly reduced these increases in vivo. The extract normalized antioxidant enzyme activities (catalase, SOD and glutathione peroxidase) and antioxidant isozyme patterns. Histopathological results revealed a significant level of protection against liver damage. Overall, the results showed that EEOSL has strong antiplatelet and hepatoprotective properties, likely due to its ability to modulate platelet signaling pathways and increase antioxidant defense mechanisms.

Abstract: Animal models are standard for safety evaluation, yet physiological differences limit human translation. Doxorubicin (DOX), a chemotherapeutic, can cause off-target gastrointestinal (GI) toxicity and treatment discontinuation. This study evaluated human colonoids as a potential human-relevant epithelial model for DOX-induced GI toxicity by comparing transcriptomic responses across human colonoids, mouse colonoids, and male C57BL/6J mouse colon tissue. Within each dataset, DOX-treated conditions were pooled across model-specific exposure levels and time points to prioritize robust DOX-associated transcriptional signatures. Using a parallelogram approach, differential expression, co-expression, pathway mapping, and Comparative Toxicogenomics Database (CTD) benchmarking were applied to compare model concordance and identify DOX-responsive mechanisms. Shared responses converged on cell-cycle regulation, DNA damage response, DNA repair, and apoptosis. DEG-level concordance was highest between mouse colonoids and mouse colon, while pathway mapping showed similarities between colonoid systems. A core set of p53-associated genes, including BAX, INKA2, and ZMAT3, was shared across datasets, with additional apoptotic and DNA damage response features observed in colonoids. CTD benchmarking supported DOX biology and highlighted underrepresented GI-relevant signals, indicating gaps in intestinal toxicogenomic annotations. Colonoid-based transcriptomics supports human colonoids as controlled epithelial models for mechanistic GI toxicity assessment, although missing vascular, immune, and systemic context means clinical validation remains necessary.

Abstract: Background: VERO cells, derived from the kidney epithelium of the African green monkey, are widely used in virology, but their ability to metabolize xenobiotics is not fully understood. Since cytochrome P450 (CYP) enzymes participate in xenobiotic metabolism, we investigated which CYP genes are expressed in VERO-E6 cells. Methods: Reverse Transcription- quantitative Polymerase Chain Reaction (RT-qPCR) showed that VERO-E6 cells express CYP3A4, CYP3A5, and CYP3A7. In contrast, CYP1A1, CYP2E1, and CYP2D6 transcripts were at the low detection level. To determine whether the encoded enzymes have the potential to activate aflatoxin B1 (AFB1), we used artificial intelligence (AI) -based structural modeling along with molec-ular docking. Results: AI modeling indicated CYP3A enzymes position AFB1 in a manner that supports the formation of the reactive intermediate, and CYP3A4 showed the most favorable orientation. To demonstrate AFB1 bioactivation, we exposed VERO-E6 cells to 200 nmol/L AFB1. After 10 days, we observed about 40 % cell death. Liquid chromatography-tandem mass spectroscopy (LC–MS/MS) analysis confirmed the presence of AFB1-derived DNA adducts, indicating that metabolic activation occurred in these cells. Conclusion: These results suggest that VERO-E6 cells have functional CYP-mediated metabolic activi-ty. Thus, combining computational and experimental approaches elucidates xenobiotic metabolism in cells where biochemical data are limited.

Abstract: Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants with established carcinogenic properties traditionally linked to genotoxicity, oxidative stress, and DNA adduct formation. Emerging evidence, however, suggests that PAHs also function as chronotoxic agents capable of disrupting circadian homeostasis through transcriptional and epigenetic reprogramming of core clock genes. This review critically examines the molecular interplay between PAH exposure, circadian clock dysregulation, and the initiation and progression of lung and breast cancers. Central to this interaction is the activation of the aryl hydrocarbon receptor (AhR), which exhibits functional crosstalk with circadian regulators including CLOCK and BMAL1. Sustained AhR activation, coupled with oxidative stress, inflammatory signaling, and epigenetic modifications such as DNA methylation, histone remodeling, and non-coding RNA dysregulation, contributes to altered rhythmic expression of key circadian genes including PER, CRY, BMAL1, and CLOCK. These alterations impair DNA repair, cell-cycle regulation, apoptosis, and metabolic homeostasis, thereby creating a permissive environment for tumorigenesis. The review further highlights tissue-specific mechanisms underlying PAH-induced chronodisruption in lung and breast tissues and discusses the translational relevance of circadian biomarkers in cancer prognosis and therapy. Finally, emerging therapeutic strategies including chronotherapy, circadian-targeted interventions, and epigenetic modulation are explored as potential approaches for mitigating environmentally induced carcinogenesis. Collectively, this review positions environmental chronotoxicology as a critical framework for understanding the temporal dimension of cancer development associated with PAH exposure.

Abstract: DNA sequence context plays a critical role in modulating the mutational effects of DNA damage. Here, we investigated how base identity influences the replication bypass and mutagenicity of a site-specific dG-AAF (2-acetylaminofluorene) bulky adduct in the well-defined AG*N and TG*N sequence contexts. By selecting A (purine) and T (pyrimidine) as representative 5’-flanking bases and systematically varying the 3’-base, we established a controlled system to examine sequence-dependent lesion replication. We found that the 5’-flanking base strongly affects the bypass profile, with AG*N sequences exhibiting uniformly low bypass (≤ 9.7%) and TG*N sequences showing markedly elevated bypass (23.6 – 50.4%) with strong sequence dependence. These differences may arise from the structure of the dG-AAF, whose conformation heterogeneities are sensitive to the flanking sequence context. In contrast, mutagenicity remains consistently low across all sequences examined, with a low frequency of point mutations and no detectable frameshift events. These results reveal a clear decoupling between lesion bypass efficiency and replication fidelity, where sequence context strongly controls lesion tolerance but has limited impact on mutagenicity. In total, our findings demonstrate that DNA sequence affects lesion processing, providing insights into how local sequence context shapes genome stability and mutational processes.

Abstract: Cadmium (Cd) is a global toxic pollutant and a major foodborne hazard. Its widespread use in industrial processes, including its presence in fertilizers, combined with natural environmental occurrence, has led to persistent contamination of food and water supplies. Ingested Cd has been associated with visual impairments, but early predictors such as disruptions to nervous system function are elusive largely due to the reliance of in vitro and in vitro assays. Here, we examined the effects of human relevant dietary Cd concentrations (0, 30, and 600 µg/g Cd) on in vivo neuronal calcium (Ca²⁺) activity and visually-guided behavior, as assessed by the optomotor response, across multiple exposure windows. We found that human relevant dietary Cd exposure induced immediate deficits in whole brain neuronal activity that preceded impairments in the optomotor response. While Cd disrupted in vivo neuronal Ca²⁺ activity in zebrafish after a single day of exposure, these effects were transient, with differences across treatments diminishing after two weeks. In contrast, optomotor deficits emerged after two weeks of exposure and were concentration dependent. Notably, while alterations in neuronal Ca²⁺ activity occurred at Cd exposure levels comparable to those in human populations, early-life optomotor deficits were observed only at dietary Cd concentrations at the upper limit of human exposures. Overall, these findings demonstrate that ingested Cd poses significant risks to sensitive systems, including the nervous system, with downstream consequences for visually-guided behavior. This study provides insight into early neurophysiological predictors of dietary Cd–induced neurotoxicity and visual dysfunction.

Abstract: Perfluorohexanesulfonic acid (PFHxS) is a per- and polyfluoroalkyl substance (PFAS) frequently detected in aquatic environments, while chlorpyrifos (CPF) is a widely used organophosphate insecticide. Although their individual toxicity is well described, their combined effects remain poorly understood. Here, we evaluated the effects of CPF (0.7 to 700 µg/L), alone or in combination with PFHxS (10 µg/L), in zebrafish embryos. Survival, hatching, malformations, locomotor activity, oxidative stress, apoptosis, and gene expression were assessed after five days of exposure. CPF reduced survival in a concentration-dependent manner, with moderate enhancement under co-exposure, while hatching success was unaffected. Deformities increased with CPF concentration, which remained consistent with PFHxS co-exposure, suggesting toxicity was mediated by CPF. Locomotor activity was largely decreased in a concentration- and phase-dependent manner. No significant changes were observed in ROS levels nor apoptosis. Gene expression analysis revealed upregulation of neurotoxicity-related markers (ache, gfap, shha, syn2a), particularly at intermediate CPF concentrations and under co-exposure. Oxidative stress–related genes showed differential responses, with sod1 upregulated and cat downregulated only in the combined treatment. These findings highlight the importance of evaluating mixture toxicity to better understand the ecological risks of co-occurring contaminants.

Abstract: 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47) is a persistent organic pollutant detected in coastal environments. The effects of BDE-47 on mangrove plants at the molecular and histological levels remain elusive. In this study, seedlings of the man-grove species Avicennia marina were exposed to BDE-47 at concentrations of 0, 1 and 10 ng L-1 for 20 days under hydroponic conditions. Leaf growth parameters, anatomical structures, and transcriptomic profiles were examined. At 1 ng L-1 BDE-47, no signif-icant changes were observed in leaf growth or vascular tissue morphology. However, transcriptome analysis showed significant enrichment of differentially expressed genes in the linoleic acid metabolism pathway, indicating that A. marina initiates early stress perception via enhanced stress perception and signal transduction, trigger adaptive defense responses to low-level BDE-47 exposure, and circumvent growth inhibition. At 10 ng L-1 BDE-47, leaf area, width, length, and fresh weight were all reduced. In addi-tion, histological examination revealed vascular bundle sheath atrophy, impaired xy-lem and phloem development, reduced parenchyma cell diameter, and a decreased proportion of intercellular space. Transcriptomic analysis at 10 ng L^-1 exposure identi-fied significant enrichment of differentially expressed genes in the circadian rhythm and spliceosome pathways, indicating that the pollutant's toxicity has progressed from local metabolic disruption to perturbation of the plant's core regulatory network. Overall, our findings reveal distinct response patterns of A. marina leaves to BDE-47 exposure at environmentally relevant concentrations, initially elucidate the adaptive defense mechanism and underlying molecular basis of toxic effects in mangrove plants under low-concentration BDE-47 exposure, and provide critical scientific support for the ecological risk assessment and conservation of coastal mangrove wetlands.

Abstract: Chronic lung disease of prematurity (CLD) is a common complication of preterm birth with a com-plex pathology. Recent epidemiologic studies have identified a link between neonatal exposure to di(2-ethylhexyl) phthalate (DEHP), frequently used in medical equipment, and the development of CLD. We hypothesize that DEHP exposure in the early neonatal period contributes to lung injury in newborn rats. Newborn rat pups were raised in one of the following environments: room air (RA), RA + DEHP, hyperoxia (60% oxygen), and hyperoxia + DEHP. Ambient DEHP was inhaled in a dose of 25mg/m3 for 6 hours daily for 14 days. Lung tissue and blood samples were collected on day 14 of life. Independent exposure to DEHP and hyperoxia resulted in thicker pulmonary septal walls, fewer alveoli, increased pulmonary polymorphonuclear leukocytes and myeloperoxidase (MPO) activity and decreased expression of CD31 on endothelial cells in lung tissue. Additionally, DEHP-exposed rats showed higher serum malondialdehyde (MDA) levels and reduced vascular endothelial growth factor (VEGF) mRNA and protein levels compared to controls. Our experiments demonstrate that inhaled DEHP, with or without hyperoxia, resulted in a similar pattern of morphological lung injury and inflammation characteristic of CLD, and a causative link to CLD of prematurity.

Abstract: Mangrove wetlands are important coastal ecosystems and are increasingly vulnerable to heavy metal contamination. The accumulation of heavy metals in man-grove ecosystems is well studied; however, studies on the seasonal variations of heavy metals in mangrove wetlands are scarce. This study investigated heavy metal (Cd, Cr, Cu, As, Pb, and Zn) accumulation in surface sediments of six typical mangrove wet-lands (DZG, QLH, XCP, SYR, SBW, and XY) in Hainan Island, China, during wet and dry seasons. In addition, potential ecological concerns and relationships between sedimentary physicochemical parameters and metal accumulation were assessed. The findings demonstrated significant spatial differences in heavy metal accumulation, with higher concentrations in the northern localities and lower concentrations in the southern areas. There were notable seasonal fluctuations in heavy metal concentrations, with higher levels in the dry season. Risk assessment models exhibited that Cadmium (Cd) and Arsenic (As) were the principal contaminants of concern in most research sites with moderate levels of contamination and posed at least moderate ecological concerns in both wet and dry seasons. The overall ecological risk index indicated a moderate risk to the environment, especially in the dry season. The principal component analysis (PCA) and correlation analysis results indicated that the physicochemical properties of sediments, mainly total organic carbon (TOC), total phosphorus (TP), total nitrogen (TN), and salinity, had significant effects on the heavy metals accumulation in the mangrove sediments. The present study helps raise awareness of seasonal fluctuations in heavy metal pollutants and provides strategies for the prevention and monitoring of metal pollution in mangrove wetlands.

Abstract: Microplastics (MPs) are widespread pollutants in aquatic environments, but their impacts throughout the life cycle remains of organisms are still not well understood. This systematic review integrates recent experimental results on the developmental, physiological, and neurobehavioral effects of MPs exposure on zebrafish (Danio rerio), a popular model organism for ecotoxicology research. A PRISMA-guided search using Web of Science (WoS) and Scopus as databases generated 371 articles, which was screened to 60 eligible articles. The collated results showed that MP toxicity strongly related to concentration, size, and extent of weathering or aging at various life stages of zebrafish. For developmental toxicity, a concentration-dependent yielded peer-reviewed publications assessing specific MPs properties, such as polymer identity, size, concentration, shape, and aging status. At various life stages, the toxicity of MPs was most affected by concentration, size, and aging. The developmental toxicity showed a concentration-dependent decrease in the rate of hatching, growth inhibition, and cardiac dysfunction, while, an increase in malformations, especially at concentrations of ≥100 µg/L or ≥10 mg/L has been reported. Non-monotonic and threshold effects have also been observed, the complexity of particle-based versus mass-based concentrations. Weathered and photo-aged MPs were found to exhibit higher embryotoxicity and neurodevelopmental toxicity, including changes in gene expression of neurons, decreased integrity of motor neurons, and impaired retinal development, compared with virgin MPs. Furthermore, physiological endpoints showed that oxidative imbalance was a key mechanistic process, which included changes in the activity of antioxidant enzymes (SOD, CAT, GPx), lipid peroxidation, inflammation, and disruption of tight junctions. Chronic MP exposures caused changes in the gut microbiota, hepatic metabolism, endocrine disruption, reproductive damage, thyroid function disruption, and genotoxicity in zebrafish. Neurobehavioral alterations, such as changes in locomotor activity, anxiety response, neurotransmitter homeostasis, and acetylcholinesterase function, occurred in both larvae and adults, with a potentiation effect in aged MP exposure. Previous, experimental data have also shown that zebrafish are very sensitive to MPs exposure in various biological systems, with toxicity being a function of physicochemical properties and exposure conditions. Finally, this review found major limitations for inter-study comparisons because of inconsistencies and differences in methodology related to MP concentration, simulation of MP aging, and MP dose measurements.

Abstract: The microbiota-gut-brain axis (MGBA) represents a bidirectional neuroendocrine system essential for maintaining metabolic and neurological homeostasis. While dietary macronutrients are known modulators of this axis, the cumulative impact of modern industrial xenobiotics remains insufficiently characterized. This review synthesizes contemporary, multidisciplinary evidence to elucidate how four ubiquitous environmental stressors Particulate Matter (PM2.5), Microplastics (MPs), Inorganic Nanoparticles (NPs), and Non-Nutritive Sweeteners (NNS) synergistically perturb this delicate enteric ecosystem. We integrate independent lines of research to propose a unifying pathological framework: these agents induce profound dysbiosis, significantly depleting beneficial, short chain fatty acid (SCFA) producing taxa (e.g., Lachnospiraceae, Faecalibacterium) and sharply diminishing the bioavailability of critical neuroactive mediators, including butyrate, GABA, serotonin, and indole derivatives. Concurrently, NNS-driven bacteriostatic shifts, the MP “plastisphere” phenomenon, and NP-induced oxidative mucosal abrasion critically compromise the intestinal barrier. This “leaky gut” facilitates the unrestricted systemic translocation of lipopolysaccharides (LPS) and trimethylamine-N-oxide (TMAO), driving a peripheral Treg/Th17 immune imbalance that propagates via the gut-liver and gut-heart axes directly to the central nervous system (CNS). Crucially, the synthesis of this data points toward a potential “Dual-Hit” mechanism, suggesting that these xenobiotics aggravate neurological pathology through simultaneous mechanisms: acting as direct neurotoxicants via CNS translocation (e.g., NPs crossing the blood-brain barrier to trigger epigenetic reprogramming and amyloid aggregation) while concurrently driving “bottom-up” systemic neuroinflammation. By linking these disruptions to classic neurodegeneration (Alzheimer’s, Parkinson’s) as well as underexplored pathologies (migraine, epilepsy, restless leg syndrome, and substance use disorders), this review underscores the urgent need for a paradigm shift in environmental neurotoxicology and the development of targeted microbiome-based interventions.

Abstract: Lipid nanoparticles (LNPs) are central to modern mRNA therapeutics, including COVID‑19 vaccines. Far from passive carriers, their ionizable lipids actively interact with cellular membranes. Evidence from cellular, transcriptomic, and proteomic studies indicates that LNPs, with or without nucleic acid, alter gene and protein expression, thereby initiating inflammatory, detoxification, and stress responses at the membrane. Key pathways affected include lipid metabolism and detoxification, with roles for Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) and cytochrome P450 enzymes. We hypothesize that the phosphatidylinositol (PI) cycle is the primary site of LNP-induced perturbations, regulating membrane restructuring and organelle trafficking during endocytosis. Disruption of this cycle triggers downstream signaling cascades, including Nuclear Factor kappa B (NF-κB), Mitogen-Activated Protein Kinases (MAPKs), Janus kinase/signal transducers and activators of transcription (JAK/STAT), and Mechanistic Target of Rapamycin (mTOR). We term this systemic effect lipid-nanoparticle-driven membrane dysfunction (L‑DMD), characterized by dysregulated cellular communication, stress responses, and energy balance. This review provides a mechanistic framework for understanding the persistent biological effects of modified modRNA-LNP exposure and emphasizes a systems-level intracellular perspective.