Search Results (1,047)

Obesity and pediatric fatty liver disease are increasingly prevalent, yet the underlying mechanisms linking these conditions to heightened inflammatory and immune responses remain poorly understood. Using a murine model reflecting early-life obesity and hepatic steatosis, we tested the hypothesis that obesity-driven hepatic inflammation intensifies systemic immune responses and exacerbates vascular dysfunction following innate immune activation. Newly weaned C57BL/6 mice were fed either a high-saturated-fat, high-cholesterol diet (HFD) or a control diet (CD) for four weeks, modeling adolescence in humans. HFD-fed mice exhibited hepatic and splenic enlargement, elevated plasma cholesterol levels, increased activity levels of liver enzymes (alanine and aspartate aminotransferases), and higher plasma serum amyloid A (SAA) concentrations. Following a sublethal dose of lipopolysaccharide (LPS), the expression of hepatic inflammatory genes (VCAM-1 and iNOS) was significantly elevated in HFD-fed mice, indicating an exaggerated local immune response. Mice fed an HFD also showed significant impairment in endothelium-dependent vasorelaxation compared to CD mice and saline-treated controls, while endothelium-independent responses remained intact. These vascular changes occurred in the context of hepatic inflammation, suggesting that early-life diet-induced steatosis sensitizes the vasculature to inflammatory insult. These findings suggest that obesity-driven hepatic inflammation primes exaggerated systemic immune responses to innate immune stimuli, potentially contributing to the vascular dysfunction and variable clinical morbidity observed in pediatric inflammatory conditions. Full article

The research on the effect of feed with probiotic additives on the growth and functional state of young steelhead salmon (Salmo gairdneri) is presented in this study. For the first time, target strains selected not only by antagonism to pathogens but also by their ability to produce lytic enzymes or secondary metabolites with antioxidant activity were used to create probiotic preparations for aquaculture. This study presents findings showing that groups of fish fed probiotic feeds showed an improved growth performance and higher survival rate compared to the control. It was noted that the weights of fish in the first variant and the second variant of the experiment were higher by 8.8% and 6.8%, respectively. This research showed that juvenile steelhead salmon reared with probiotic-supplemented feeds had an improved ability to survive in high salinity and sublethal temperatures. This indicates that probiotics may play a significant role in enhancing the adaptive system of fish. Full article

Bothus podas (wide-eyed flounder) is a benthic flatfish likely exposed to microplastic (MP) pollution. We investigated MP ingestion and associated physiological effects in wild B. podas collected from Mallorca (Balearic Islands), Spain. Markers of oxidative stress, detoxification, and immunity were quantified in intestinal, hepatic, and splenic tissues. MPs were observed in the gastrointestinal tracts of 87.5% of the 24 specimens analyzed, with an average of 3.8 ± 0.6 items per fish. Fiber-type MPs predominated in both the gastrointestinal tract (69.6%) and sediment samples (97%). Additionally, micro-Fourier transform infrared spectroscopy analysis confirmed that the majority of ingested MPs were composed of polyethylene, polypropylene, and polyester. Fish were categorized into low (<3 items) and high (≥3 items) MP groups based on the median number of plastic items found in the gastrointestinal tract to assess sublethal impacts. In the gut, high-MP fish exhibited significantly elevated activities of detoxification enzymes: ethoxyresorufin-O-deethylase (phase I) and glutathione s-transferase (phase II), along with increased antioxidant enzyme superoxide dismutase and inflammatory myeloperoxidase. Gut catalase and malondialdehyde (MDA) were not significantly different between groups. In liver tissues, no biomarkers differed significantly with MP exposure. In the spleen, lysozyme and alkaline phosphatase activities were significantly higher in high-MP fish, while splenic MDA remained unchanged. These results indicate that gastrointestinal MP exposure triggers local oxidative stress responses and systemic immune activation in B. podas. Overall, ingestion of environmentally relevant MP levels elicited detoxification and inflammatory responses without significant increases in MDA, an indicator of oxidative damage, highlighting the physiological stress imposed by plastic pollution on benthic fish. Full article

Pharmaceuticals such as fluoxetine, paroxetine, sertraline, and mianserin occur in aquatic environments at low yet persistent concentrations due to their incomplete removal in wastewater treatment plants. Although frequently detected, these neuroactive compounds remain underrepresented in ecotoxicological assessments. Given their pharmacodynamic potency, environmentally relevant concentrations may induce sublethal effects in non-target organisms. In this study, we applied untargeted LC-MS-based metabolomics to investigate the sublethal effects of four widely used antidepressants—paroxetine, sertraline, fluoxetine (SSRIs), and mianserin (TeCA)—on two ecologically relevant freshwater invertebrates: S. ambiguum and D. magna. Organisms were individually exposed to each compound for 48 h at a concentration of 100 µg/L and 25 µg/L, respectively. Untargeted metabolomics captured the sublethal biochemical effects of these antidepressants, revealing both shared disruptions—e.g., in glycerophospholipid metabolism and cysteine and methionine metabolism—and species-specific responses. More pronounced pathway changes observed in D. magna suggest interspecies differences in metabolic capacity or xenobiotic processing mechanisms between taxa. Among the four antidepressants tested, sertraline in D. magna and fluoxetine in S. ambiguum exerted the most extensive metabolomic perturbations, as evidenced by the highest number and pathway impact scores. In D. magna, fluoxetine and mianserin produced similar metabolic profiles, largely overlapping with those of sertraline, whereas paroxetine affected only a single pathway, indicating minimal impact. In S. ambiguum, paroxetine and mianserin elicited comparable responses, also overlapping with those of fluoxetine, while sertraline triggered the fewest changes. These results suggest both compound-specific effects and a conserved metabolic response pattern among the antidepressants used. They also underscore the considerable potential of metabolomics as a powerful and sensitive tool for ecotoxicological risk assessments, particularly when applied across multiple model organisms to capture interspecies variations. However, further research is essential to identify which specific pathway disruptions are most predictive of adverse effects on organismal health. Full article

Heavy metals are among the most persistent and bioaccumulative pollutants in marine ecosystems, posing significant toxicological threats to fish via complex molecular and cellular disruptions. This review synthesizes current knowledge on the cascade of mechanistic responses in marine fish following HM exposure, which includes oxidative stress, modulation of antioxidant responses, activation of detoxification systems, DNA damage, inflammation, apoptosis, neuroendocrine disruption, and ultimately, cellular energy imbalance. In addition to established pathways, the review highlights recent advances in mechanistic understanding and biomarker development, including cellular stress responses, epigenetic regulation, metal homeostasis mechanisms, and novel molecular indicators. These mechanisms support the development of an integrated biomarker framework that combines classical indicators (e.g., antioxidant enzymes, metallothionein) with next-generation endpoints (e.g., miRNA profiles, gene-level responses of metal transporters or stress chaperones, epigenetic alterations). The interpretation of biomarker responses requires consideration of the exposure context, environmental variables, and physiological status to ensure accurate assessment of sublethal toxicity in field settings. By bridging mechanistic understanding with biomonitoring relevance, this review provides a comprehensive foundation for advancing molecular tools in pollution monitoring and risk assessment. Special emphasis is placed on biomarkers specific to heavy metal exposure, enhancing their diagnostic value relative to general stress indicators. Full article

Mercury (Hg) pollution is a widespread ecological threat with sublethal effects on wildlife. Birds, due to their ecological diversity and sensitivity, serve as effective models for evaluating the behavioural impacts of Hg exposure. This review applies Tinbergen’s four questions: causation, ontogeny, function, and evolution, as an integrative framework. Mechanistically, Hg disrupts neuroendocrine pathways, gene expression, immune function, and hormone regulation, leading to behavioural changes such as reduced foraging, altered parental care, and impaired predator avoidance. Early-life exposure affects neural development, learning, and social behaviour into adulthood. Functionally, these changes reduce fitness by compromising reproduction and survival. Phylogenetic comparisons show interspecific variability, with piscivorous and insectivorous birds exhibiting high Hg burdens and sensitivity, linked to ecological roles and exposure. Behavioural responses often precede physiological or demographic effects, highlighting their value as early indicators. Both field and laboratory studies show that even low Hg concentrations can alter behaviour, though outcomes vary by species, life stage, and exposure route. Integrating behavioural endpoints into ecotoxicological risk assessments is essential to improve conservation strategies and understanding of sublethal pollutant effects on wildlife. Full article

Some Vibrio parahaemolyticus strains cause translucent post-larvae disease (Vp_TPD), leading to significant economic losses in shrimp farming. We aimed to identify whether a mixture of natural antimicrobials, AuraAqua (Aq), can protect white-leg shrimp (Penaeus vannamei) against the lethal effects of Vp_TPD and to understand its biological mode of action. Herein, we demonstrate that Aq, an antimicrobial mixture composed of a blend of organic acids, citrus, and olive extracts, suppressed Vp_TPD virulence at sub-inhibitory concentrations and conferred robust protection to shrimp. The minimum inhibitory and bactericidal concentrations against the Vp_TPD isolate were at 0.05% and 0.2%, respectively. At 0.05–0.1%, Aq reduced bacterial growth and downregulated six major virulence genes (vhvp-1, vhvp-2, vhvp-3, pirA_Vp, pirB_Vp, pirAB_Vp), while leaving metabolic ldh expression unaltered. Parallel in vitro assays revealed diminished adhesion of Vp_TPD to primary shrimp gut and hepatopancreas epithelial cells and a ≈50% reduction in infection-induced extracellular H₂O₂, indicating an antioxidant effect. The treatment also triggered a time-dependent surge in extracellular alkaline phosphatase (ALP) activity, consistent with membrane permeabilization. In vivo, a challenge of post-larvae with 10⁴ CFU/mL Vp_TPD resulted in 91% mortality after 45 h; co-treatment with 0.1% and 0.2% Aq reduced mortality to ≈12% and ≈6%, respectively, while 1% Aq achieved ≈98% survival. The clinical protection test confirmed that 0.1% Aq preserved high survival across four pathogen inocula (10¹–10⁴ CFU/mL). Conclusively, Aq destabilized the pathogen and therefore transcriptionally silenced multiple virulence determinants, translating into significant in-pond protection for controlling Vp_TPD for shrimp aquaculture. Full article

Trichogramma dendrolimi, a key egg parasitoid for lepidopteran pest control, faces potential risks from neonicotinoid insecticides like acetamiprid used in integrated pest management (IPM). This study evaluated acetamiprid’s acute and sublethal toxicity to T. dendrolimi and assessed population-level risks via species sensitivity distribution (SSD). Acute toxicity assays using glass-vial residues revealed a 24 h LC₅₀ of 0.12 mg a.i. L⁻¹ for adults, three orders of magnitude below the maximum field rate (100 mg a.i. L⁻¹). Sublethal exposure (1/2–1/100 LC₅₀) significantly reduced parasitism and emergence rates (NOEC = 2.3 μg a.i. L⁻¹) but did not affect offspring survival. Acetamiprid also shortened offspring development at 11.5–57.5 μg a.i. L⁻¹. SSD analysis identified T. dendrolimi as the most sensitive parasitoid to acetamiprid (HC₅/HC₅₀) = 0.11/5.88 mg a.i. L⁻¹), with field rates (30–100 mg a.i. L⁻¹) indicating a potentially affected fraction (PAF) of 76.8–97.9%. These findings underscore the need to integrate sublethal effects into pesticide regulations to conserve parasitoid-mediated ecosystem services. Full article

Essential oils have emerged as promising alternatives for pest insect control. However, sublethal effects on insect reproduction and development are rarely explored, despite their relevance to integrated pest management (IPM). This study evaluated the sublethal effects of Piper hispidivervum C. DC. essential oil (EOPH) on the development and population growth of four populations of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), as well as the persistence of safrole residue in treated corn grains. Population development rates were determined using emergence curves and total emerged adults, while population growth was assessed by counting live insects in the feeding substrate at different storage intervals. Safrole residue persistence was analyzed using solid-phase microextraction in headspace mode (SPME-HS). Sublethal exposure to EOPH significantly reduced the development rate, total emergence, and growth in three of the four populations. The population from Crixás, GO, showed no significant reduction, with a population curve overlapping the control. The lethal dose was reduced by 98.20%, indicating low persistence and potential food safety. The EOPH exhibited sublethal effects on S. zeamais populations, reducing both development rates and population growth. This reduction varied among the populations studied. Further research is encouraged to explore its effects on different insect populations and under broader environmental conditions. Full article

Understanding microbial adaptation and tolerance based on the cellular concentration and biosorption capacity provides critical insights for evaluating microbial performance under heavy metal stress, which is essential for selecting efficient strains or consortia for bioremediation applications. In this study, the adaptation and tolerance of Bacillus megaterium and Rhodotorula mucilaginosa to elevated concentrations of copper (Cu) and manganese (Mn) were investigated by introducing the maximum adaptation concentration (MAC) alongside the maximum tolerable concentration (MTC) and the minimum inhibitory concentration (MIC). A Gaussian model was fitted to the relative growth responses to estimate the MACs, MTCs, and MICs. B. megaterium exhibited MACs of 4.6 ppm Cu and 393.9 ppm Mn, while R. mucilaginosa showed MACs of 59.6 ppm Cu and 64.4 ppm Mn, corresponding to concentrations that stimulated their maximum cell density. A biosorption analysis revealed average capacities of 6.3 ± 5.3 mg Cu/g biomass and 28.6 ± 17.2 mg Mn/g biomass, positively correlated with the MTCs, indicating enhanced metal uptake under sublethal stress. The co-culture assays demonstrated dynamic microbial interactions shaped by the type and concentration of metal, including coexistence, competitive substitution, and dominance by tolerance. These findings support the use of MACs as indicators of growth stimulation and MTCs as thresholds for enhanced metal uptake, providing a dual-parameter framework for selecting metallotolerant microorganisms for metal recovery strategies. Full article

The development of reversible animal models for the study of intestinal pathologies is essential to reduce the number of animals used in research and to better understand disease mechanisms. In this study, we present a reversible model of intestinal malabsorption through the administration of sublethal doses of ebulin-f, a ribosome-inactivating protein, and validate its usefulness by monitoring vitamin C absorption. The scientific community increasingly recognizes the importance of rationalizing experimental designs, optimizing treatment protocols, and minimizing the use of animals in research models. Thus, new methodologies are needed to minimize invasive sampling and to develop reversible animal models that recover physiologically post-study. Such models are essential for in vivo studies of human pathologies. Sublethal doses of ebulin-f (2.5 mg/kg) administered intraperitoneally to female Swiss CD1 mice (n = 6 per group) can cause reversible intestinal alterations in the small intestine, which offer the possibility of having a valuable reversible study model of malabsorption for the investigation of this syndrome. To verify whether nutrient absorption is altered, we used vitamin C as a traceable nutrient that can be quantified in the blood. Peripheral blood samples were collected through the retro-orbital area at 30, 80, 120, 180, and 1440 min post-administration, treated with DTT and MPA, and analyzed using a validated UV/Vis–HPLC method to indirectly determine vitamin C absorption by enterocytes. Pharmacokinetic analysis revealed significantly increased vitamin C absorption on days 1 and 3 post-treatment (AUC values of 3.65 × 10⁴ and 7.10 × 10⁴, respectively) compared to control (0.94 × 10⁴), with partial recovery by day 22 (3.27 × 10⁴). Blood concentration profiles indicate that intestinal damage peaks at day 3, followed by significant regeneration by day 22, establishing this as a viable reversible model for inflammatory bowel disease research. Full article

The use of cellular energy allocation (CEA) as a physiological energetic biomarker is useful for detecting the sublethal effects of environmental contaminants. The CEA assesses the health and energy status of organisms, serving as a reliable indicator for monitoring the health of aquatic ecosystems. This study aimed to evaluate the impact of emerging contaminants already listed as a priority for monitoring in freshwater ecosystems, namely sulfamethoxazole (0.156–2.50 mg/L), trimethoprim (25.0–400 mg/L), 4-chloroaniline (5.21–20.0 mg/L), and 3,4-dichloroaniline (0.38–4.00 mg/L), on the CEA of D. rerio embryos. A standard fish embryo toxicity test was conducted, and an adaptation of the allometric scaling approach was developed through the relationship between the size and the fresh weight of the embryos. All the compounds affected the fractions of the energy reserves (total carbohydrate, lipid, and protein contents) differently, with carbohydrates being the predominant energy fraction and the most responsive indicator. Although the energy consumed showed no significant changes, the CEA was notably altered after exposure to all the contaminants, indicating a direct connection to shifts in the available energy. The CEA alterations may indicate a reallocation of energy toward detoxification, combating the stress of contaminant exposure. Energy allocation biomarkers provide a comprehensive assessment of an organism’s physiological state, which is essential for evaluating emerging contaminants’ impacts, safeguarding aquatic ecosystems, and shaping effective environmental policies. Full article

As emerging contaminants increasingly detected in aquatic and terrestrial ecosystems, environmental estrogens (EEs) pose significant ecological risks to marine ecosystems, particularly affecting photosynthetic microorganisms occupying fundamental roles in marine food webs. This review summarizes the current knowledge on the toxicological effects of EEs in marine microalgae through a systematic analysis of dose-dependent physiological, biochemical, and molecular responses. Experimental evidence reveals a biphasic response pattern characterized by growth promotion and photosynthetic enhancement in microalgae under low-concentration EE exposure (0.1–10 μg/L), while marked inhibition of both growth and photosynthetic activity was observed at elevated EE concentrations (>50 μg/L). Notably, sustained EE exposure induces metabolic reprogramming, manifested through reduced protein and polysaccharide biosynthesis concurrent with accelerated lipid accumulation. Cellular stress responses include significant ultrastructural alterations such as chloroplast membrane disruption, cell wall thickening, and the formation of multicellular aggregates. The study further elucidates the concentration-dependent modulation of toxin metabolism, with sublethal doses stimulating intracellular microcystin synthesis (1.5–2.3-fold increase), while acute exposure triggers toxin release through membrane permeabilization. At molecular levels, transcriptomic analyses identify the up-regulation of heat shock proteins (HSP70/90) and the differential expression of genes governing cell cycle progression (cyclin-D), apoptotic pathways (caspase-3), photosynthetic electron transport (psbA), and oxidative stress responses (SOD, CAT). These findings demonstrate that EEs exert multilevel impacts on microalgal physiology through interference with fundamental metabolic processes, potentially disrupting marine primary productivity and biogeochemical cycles. The identified response mechanisms provide critical insights for environmental risk assessment and establish a conceptual framework for investigating estrogenic pollutant effects in aquatic ecosystems. Full article

This study investigated the impact of sublethal concentrations of dinotefuran on the predatory behavior and detoxification enzyme activity of Harmonia axyridis, aiming to establish a theoretical foundation for the conservation and utilization of natural enemies and the effective management of wheat aphids. This study treated wheat aphids with sublethal concentrations (LC₂₀ and LC₃₀) of dinotefuran via the leaf dipping method and subsequently used them as prey for the fourth-instar larvae of H. axyridis. The predation amount, instantaneous attack rate, handling time, daily maximum predation amount, and detoxification enzyme activity of H. axyridis were statistically analyzed. The results indicated that the predation of H. axyridis on wheat aphids conformed to the Holling II disc equation. Moreover, in comparison to the control group, the handling time of H. axyridis on wheat aphids was extended, and at the same time, the instantaneous attack rate, maximum daily predation amount, and predation efficiency were all diminished. After the ingestion of LC₂₀- and LC₃₀-dinotefuran-treated aphids, the carboxylesterase levels in H. axyridis were not significantly different from the control, with levels 0.97-fold and 0.94-fold that of the control, respectively. Glutathione-S-transferase (GST) demonstrated an induction impact compared to the control, reaching 1.96- and 1.47-fold higher than the control, respectively. The activity of mixed-functional oxidase (MFO) demonstrated an induction effect compared to the control, measuring 1.98- and 3.04-fold higher than that of the control, respectively. Consequently, the predation function and detoxification enzyme activity of H. axyridis were influenced when consuming wheat aphids treated with sublethal concentrations of dinotefuran, with significant variations across different concentrations, potentially reflecting the survival strategy of insects under dinotefuran stress. Full article

The administration of nutraceutical substances to fish diet can help to control disease outbreaks in aquaculture practices, thereby promoting sustainability and food safety. In particular, some substances have the potential to alleviate the effects of trace metals toxicity in fish also by reducing metal accumulation in tissues. This study evaluates, for the first time, the effect of nutraceutical substances on bioaccumulation mechanisms of mercury (Hg) in tissues and organs of farmed gilthead seabream (Sparus aurata) by mesocosm experimentation. The kinetics of bioaccumulation in muscle, gills, gut, liver and kidney and the detoxification efficiency were also assessed. Fish were fed with three different diets: a commercial diet used as control (CD); a diet enriched with short chain fatty acids (SCFA) and extract of Castanea sativa (D1); a diet enriched with yeast Saccharomyces cerevisiae and extract of Schinopsis balansae (D2). All groups were exposed to sub-lethal concentrations of mercury. After 20 days of exposure, mercury levels in different organs and tissues clearly revealed the effectiveness of yeast and plant extracts in limiting the metal bioaccumulation in fish fed with D2 through mercury absorption and then elimination by feces. In contrast, the D1 seems to not reduce the Hg bioaccumulation in fish tissues. This can be attributed to the high affinity of SCFA for mercury, leading to the formation of organometallic compounds absorbed by the fish tissues. This mechanism potentially counteracts the efficiency of tannins contained in the extract plant on mercury removal. This study clearly demonstrates that the use of diets enriched with yeast and/or plant extracts rich in tannins are a useful bioremediation strategy to reduce trace metals bioaccumulation in farmed fish, thus preserving their health status from intoxication, their commercial values, and consequently the health of consumers. Full article