TL;DR
Comparative toxicity indicated that the long-chain sulfonated PFAS, particularly PFOS, induced the greatest adverse effects, whereas the short-chain PFHxS exhibited comparatively lower toxicity.
Lambda-cyhalothrin is a synthetic pyrethroid insecticide widely used in agriculture, but its potential to contaminate aquatic ecosystems and exert high toxicity on fish at low concentrations raises ecotoxicological concerns. While standard histopathological and biochemical assessments are common, the novel integration of pigment-based biomarkers (hemosiderin and lipofuscin) offers unexplored mechanistic insights into tissue resilience and residual oxidative stress during postexposure recovery. This study evaluated liver changes (degree of tissue changes-DTC), pigment deposition, and biochemical profiles in Oreochromis niloticus exposed to sublethal lambda-cyhalothrin (1.24 μg L-1) for 3, 7, and 14 days, followed by a 15-day recovery phase. Exposure induced a progressive, time-dependent increase in DTC, transitioning from early reversible inflammatory/vascular lesions to irreversible parenchymal and hepatopancreatic necrosis by Day 14. This structural decline correlated with significant elevations in serum ALT and AST activities. Critically, exposed fish exhibited a sharp increase in hepatic hemosiderin and lipofuscin. Following the 15-day recovery period, lipofuscin levels and GGT activity normalized, reflecting immediate metabolic detoxification. However, elevated DTC, serum transaminases, and prominent hemosiderin deposits persisted. By tracking distinct temporal trajectories, our unique multibiomarker approach demonstrates that while immediate oxidative metabolic stress subsides after exposure ceases, iron dysregulation and structural liver damage remain unresolved. These findings emphasize that standard recovery windows in clean water are insufficient to fully restore tissues, highlighting hidden ecological risks for fish farming and wild populations exposed to pulses of agricultural runoff.
Overall, BPP (20 g/kg) may protect O. niloticus against OXY-induced liver damage through its antioxidant potential, supporting its application as a functional additive in aquaculture.
Deltamethrin is a pervasive aquatic pollutant that adversely affects fish health even at sublethal concentrations. This study evaluated deltamethrin-induced toxicity in Nile tilapia (Oreochromis niloticus) using hematological, biochemical, and histopathological biomarkers and assessed the ameliorative potential of Moringa oleifera and Arthrospira platensis as dietary supplements. Fish were randomly assigned to four groups for a total of 28 days: control, deltamethrin-exposed group, deltamethrin + M. oleifera-exposed group, and deltamethrin + A. platensis-exposed group. Deltamethrin exposure significantly (p < 0.05) reduced hemoglobin, erythrocyte indices, total protein, albumin, leukocyte counts, and globulin levels, while increasing liver enzymes, blood glucose, urea, and creatinine, indicating anemia, hepatic and renal dysfunction, and physiological stress. Exposure to deltamethrin showed severe histological anomalies such as necrosis, lamellar fusion, lamellar aneurysm, renal sinus, elongated renal tubules, formation of pyknotic nuclei, and damaged hepatic veins in the soft tissues of exposed fish. Dietary supplementation (M. oleifera and A. platensis) markedly restored hematobiochemical parameters and improved tissues histoarchitecture. These findings highlight the potential of natural nutraceuticals in mitigating pesticide toxicity and supporting sustainable aquaculture practices.
Despite the frequent co-occurrence of glyphosate and arsenic in agricultural freshwater systems, the biochemical mechanisms underlying their combined toxicity in fish remain poorly understood. Here, we evaluated the acute (96 h) individual and joint effects of glyphosate (0.5 mg/L) and arsenic [As(III), 0.5 mg/L] on the Neotropical fish Cnesterodon decemmaculatus using an integrated biomarker approach. Endpoints related to oxidative balance, DNA integrity, neurotoxicity, and energy metabolism were assessed across multiple tissues. Glyphosate exposure induced marked oxidative and metabolic disturbances, including increased catalase activity, glutathione levels, and mitochondrial electron transport system activity, along with reduced cellular energy allocation and glutathione-S-transferase activity. In contrast, arsenic decreased glutathione content, superoxide dismutase activity, lipids, and carbohydrates. Comparable DNA damage levels were observed across single and combined exposures. Co-exposure resulted in non-additive interactions, with mixture effects deviating from the sum of individual responses, leading to either reduced (antagonistic) or enhanced (potentiation) effects depending on the biomarker and its direction of change. Antagonistic interactions predominated for genotoxic and several oxidative stress biomarkers, whereas potentiation was observed for selected metabolic endpoints. Multivariate analysis revealed distinct physiological profiles among treatments, with partial overlap between glyphosate and mixture responses. These findings underscore the complexity of pollutant mixture effects and highlight the need to incorporate combined exposures into ecotoxicological risk assessment.
The overuse of the broad-spectrum antibiotic florfenicol (FF) and its residues in coastal benthic environments pose toxicological risks to marine crustaceans. As an economically important benthic species, the mud crab is vulnerable to FF pollution stress, yet its toxicological responses and underlying mechanisms remain unclear. Therefore, this study investigated the physiological, biochemical, and transcriptomic responses of the mud crab hepatopancreas following FF exposure. Healthy mud crabs were assigned to one control group and three FF exposure groups (5, 50, and 500 μg/L) and exposed for 10 days. The results demonstrated that FF accumulated in the hepatopancreas in a concentration-dependent manner, significantly reduced the weight gain rate and hepatosomatic index, and induced marked histopathological alterations. Furthermore, FF stress significantly elevated MDA content, disrupted the homeostasis of antioxidant and detoxification systems (including SOD, CAT, GST, GSH, and T-AOC), and induced oxidative stress. Transcriptomic analysis and gene set enrichment analysis (GSEA) showed that FF impaired lipid metabolism mainly by suppressing PPAR signaling and inhibiting fatty acid synthesis and degradation. FF exposure was also associated with persistent downregulation of melanogenesis-related pathways, suggesting potential impairment of innate immune-related functions. These alterations likely contributed to growth inhibition in mud crabs under FF stress. Weighted gene co-expression network analysis (WGCNA) combined with protein-protein interaction (PPI) analysis identified HSPA8 and phc-2 as candidate hub genes potentially associated with compensatory detoxification and epigenetic growth restriction, respectively. These findings elucidate the molecular regulatory networks underlying FF-induced hepatopancreatic damage, providing useful evidence for the environmental risk assessment and toxicological evaluation of antibiotic residues in mud crab aquaculture.
Despite the recognized antioxidant properties of phycobiliproteins (PBPs) from Limnospira platensis, their potential application in bivalve aquaculture—particularly regarding their modulation of endogenous antioxidant defenses—remains largely unexplored. This study evaluated the effects of an aqueous PBP extract at concentrations of 2, 20, and 80 µg/mL on antioxidant parameters in the Pacific oyster Magallana gigas following 24, 48 and 96 h exposure periods. Activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), levels of lipid peroxidation (TBARS) and protein oxidation, and expression of corresponding genes in gills and hepatopancreas have been evaluated. PBPs elicited significant effects on prooxidant–antioxidant balance in oyster tissues. Low concentrations (2–20 µg/mL) enhanced SOD and CAT activities and reduced protein oxidation, indicating protective effects. The highest concentration (80 µg/mL) suppressed enzyme activities—particularly GPx—while elevating TBARS, suggesting prooxidant effects at excessive doses. Tissue-specific responses were observed, with hepatopancreas more vulnerable to oxidative stress than gills. Notably, GPx transcription was upregulated at 80 µg/mL of PBP extract despite suppressed activity, implying its post-transcriptional regulatory properties. These findings demonstrate that L. platensis PBPs modulate oyster antioxidant status in a biphasic manner, with moderate doses conferring stimulation and high doses inducing oxidative stress. This study provides the first integrative evidence of PBP effects on enzymatic, and transcriptional antioxidant defenses in a commercially important bivalve, underscoring their promise as functional bioactive additives while emphasizing the need for careful dose optimization.
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