Cocktails of pesticide residues in Prochilodus lineatus fish of the Salado River (South America): First record of high concentrations of polar herbicides

Assessing nanoencapsulated geraniol as a safer pesticide alternative: insights from biomarker responses in a neotropical fish species

Geraniol, a monoterpene essential oils, has been investigated as a sustainable alternative to conventional pesticides. Its action may benefit from using the nanoencapsulation technique, which could enhance its properties. In this study, we assessed the effects of acute exposures to geraniol and nanoencapsulated geraniol on biomarkers of the Neotropical teleost Prochilodus lineatus. For this, juveniles of P. lineatus were exposed to a control group containing water and the solvent (CTR - Pluronic F-68®), zein nanocapsules (NANO), nanoencapsulated geraniol (nGER), or geraniol in its conventional form (GER), all at a concentration of 5 mg L-1. After exposures (24 and 96 h), biochemical, genotoxic, physiological, and histological biomarkers were analyzed in blood, brain, muscle, liver, and gills. When compared to respective controls, our results showed a significant increase in DNA damage in the erythrocytes of fish exposed to GER and increased acetylcholinesterase activity in the brain of animals exposed to nGER and GER, as well as a significant decrease in glutathione content in the gills of animals exposed to nGER. However, empty zein nanocapsules were toxic to the animals, given the total mortality of the NANO group after 24 h exposure. Thus, compared to NANO, nGER was less harmful, suggesting that the interaction of geraniol with the nanocapsules attenuated the effects induced by the empty NANOs. Overall, nanoencapsulated geraniol caused fewer effects in P. lineatus than geraniol. However, further studies should be carried out before its use as an alternative to more sustainable agriculture.

Rational application of QoIs fungicides to achieve a rice-fungi-fish interaction balance within paddy ecosystems

In the realm of agricultural chemical research, elucidating the mechanisms underlying the selectivity of quinone outside inhibitors (QoIs) is crucial for guiding the development of novel pesticides. In this study, differences in the selectivity and toxicity of 12 QoIs were evaluated using three organisms (Magnaporthe oryzae, zebrafish, and rice) present in paddy fields. The interplay between the specific mechanisms of QoIs selectivity among different organisms and the variations in individual toxicity remains unclear. Therefore, the distinct levels of enrichment behavior, cell toxicity, and target enzyme toxicity of 12 QoIs across three organisms were investigated in this research. Additionally, an attempt was made to analyze the correlation between structural parameters and the degree of toxicity at the tissue, cellular, and target levels to establish the regulatory direction of QoIs activity and toxicity. The results revealed that cytotoxicity and target enzyme toxicity played significant roles in the toxicity observed in individuals, specifically in fish and fungus, respectively. The results of this study revealed a significant negative correlation between the bioconcentration factor (BCF) in biological tissues and fish toxicity (LC50) (P < 0.05), but no significant correlation between BCF of fungus and fungitoxicity (EC50) was detected (P > 0.05). Reducing the Log P (octanol-water partition coefficient) and further changing tissue enrichment could balance the toxicity and activity of QoIs in organisms. On the basis of the aforementioned findings, introducing hydrophilic groups into the structure of pyraclostrobin with lower Log P values was an effective strategy for designing new QoI structures. These modified structures demonstrated reduced toxicity to fish and promising fungitoxicity against rice blast fungus compared with pyraclostrobin. This study provides valuable insights for regulatory measures in the design and development of effective and safe new QoIs in paddy fields, further reducing adverse impacts on paddy fields and aquatic ecosystems.

Noble metal/metal-organic framework nanoparticle-based electrochemical sensors for evaluating fish quality: a comprehensive review

Fish quality is a big-picture issue because of the possible presence of many chemical and biological pollutants, that may affect fish leading to environmental and health hazards. In this regard, researchers focus on developing efficient strategies for evaluating fish quality in terms of safety and freshness. Fish safety is determined based on assessing various pollutants, such as heavy metals, pesticides, dyes, and drugs, in fish tissue. Additionally, fish freshness evaluation is based on assessing some indicators including xanthine, hypoxanthine, uric acid, and histamine. Many chromatographic methods can assess all of these chemical indicators to evaluate the fish quality. However, these methods are expensive and often require sophisticated steps. Thus, electrochemical methods based on noble metal nanoparticles (NMNPs), metal-organic frameworks (MOFs) NPs, and their composites as electrode modifiers were investigated as potential replacements for the chromatographic ones. These materials showed high catalytic activity and electrical conductivity compared to the other electrode modifiers. In this review, we spotlight the role of NMNPs and MOF NPs in evaluating the quality of fish samples as a food source. Overall, NMNPs and MOF NPs are considered promising electrode materials for the electrochemical monitoring of fish quality.

Green Glyphosate Treatment with Ferrihydrite and CaO2 via Forming Surface Ternary Complex

Glyphosate (PMG) is a globally used broad-spectrum herbicide and receives environmental concerns because of its moderate persistence and potential carcinogenicity. Traditional PMG treatment methods often suffer from the generation of a more toxic and persistent aminomethylphosphonic acid (AMPA) intermediate. Herein, we develop a green method with ferrihydrite (FH) and CaO2 (FH/CaO2) via regulating the coordination of PMG with FH and Ca2+, where the phosphonate group of PMG preferentially binds to FH and its carboxylate side complexes with Ca2+ released by CaO2, forming a FH-PMG-Ca ternary surface complex. This unique ternary complex can redistribute electrons within the PMG molecule for its C-P activation and C-N bond stabilization, favoring the selective C-P bond attack of superoxide radical produced by the Fenton reaction between CaO2-derived H2O2 and FH, thus generating environment-friendly glycine instead of AMPA. The FH/CaO2 process realizes over 99% PMG degradation in industrial wastewater within 1 h, with residual PMG < 0.1 ppm and AMPA < 40 ppb. More importantly, the CaO2 consumption was as low as 3.1 mg of CaO2/mg of PMG, one-fifth those of previously reported CaO2-based counterparts. This study provides an effective and environment-friendly PMG treatment strategy and highlights the importance of surface coordination modes on the degradation pathway of PMG.

Glyphosate and aminomethylphosphonic acid impact on redox status and biotransformation in fish and the mitigating effects of diet supplementation

Fish reared under seminatural conditions can be challenged by exposure to herbicides. Farming facilities relying on the surrounding area's water quality can be affected by glyphosate and aminomethylphosphonic acid (AMPA) contamination. This review summarizes findings on how glyphosate and AMPA in the amounts registered in surface waterbodies affect redox status and biotransformation in fish and covers the aspect of diet supplementation for oxidative stress relief. Environmentally relevant concentrations of glyphosate and AMPA can alter the transcription and catalytic activities of antioxidant enzymes, decrease the content of reduced glutathione, and increase the accumulation of lipid peroxidation products, all of which are signs of a redox imbalance. Glyphosate has been shown to affect complex I in the mitochondrial respiratory chain and dysregulate iron transport-related genes, causing redox disturbance. Relatively high but environmentally realistic glyphosate concentrations can initiate the induction of cytochrome P450 biotransformation enzymes, alter the regulation of ABC exporters, and cause the inhibition of the redox-sensitive Nrf2 signaling pathway. Studies on reducing herbicide toxicity through dietary supplementation are a promising area of research. Natural functional supplements have been proven to have great potential for mitigating glyphosate-induced oxidative stress and thereby improving fish health, which in turn means maintaining productivity in fish farms that use natural water. However, data on the effects of AMPA on fish are scarce, and studies on the alleviation of its toxicity in fish are lacking. Considering the variety of AMPA contamination routes, one cannot underestimate the need for further research.

Epigenetic alteration of uterine Leukemia Inhibitory Factor gene after glyphosate or a glyphosate-based herbicide exposure in rats

Glyphosate-based herbicides (GBHs) or its active ingredient, glyphosate (Gly), induce implantation failure in rats. We aimed to elucidate a mechanism of action of these compounds assessing the transcriptional and epigenetic status of the receptivity marker, leukemia inhibitory factor (Lif) gene. F0 rats were orally exposed to GBH or Gly at 3.8 or 3.9 mg Gly/kg/day, respectively, from gestational day (GD) 9 until weaning. F1 females were mated and uterine samples collected at GD5. Methylation-sensitive restriction enzymes (MSRE) sites and transcription factors were in silico predicted in regulatory regions of Lif gene. DNA methylation status and histone modifications (histone 3 and 4 acetylation (H3Ac and H4Ac) and H3 lysine-27-trimethylation (H3K27me3)) were assessed. GBH and Gly decreased Lif mRNA levels and caused DNA hypermethylation. GBH increased H3Ac levels, whereas Gly reduced them; both compounds enhanced H3K27me3 levels. Finally, both GBH and Gly induced similar epigenetic alterations in the regulatory regions of Lif.

Perinatal Exposure to Glyphosate or a Commercial Formulation Alters Uterine Mechanistic Pathways Associated with Implantation Failure in Rats

Perinatal exposure to a glyphosate-based herbicide (GBH) or its active ingredient, glyphosate (Gly), has been demonstrated to increase implantation failure in rats. This study investigates potential mechanisms of action, analyzing uterine preparation towards the receptive state. Pregnant Wistar rats (F0) were treated orally with GBH or Gly (3.8 and 3.9 mg Gly/kg/day, respectively) from gestational day (GD) 9 until weaning. Adult F1 females became pregnant and uterine samples were collected on GD5 (preimplantation period). Histomorphological uterine parameters were assessed. Immunohistochemistry was applied to evaluate cell proliferation and protein expression of estrogen receptors (ERα and ERβ), cell cycle regulators (PTEN, cyclin G1, p27, and IGF1R-α), and the Wnt5a/β-catenin/FOXA2/Lif pathway. Both GBH and Gly females showed increased stromal proliferation, associated with a high expression of ERs. Dysregulation of PTEN and cyclin G1 was also observed in the Gly group. Reduced gland number was observed in both groups, along with decreased expression of Wnt5a/β-catenin/FOXA2/Lif pathway in the glandular epithelium. Overall, GBH and Gly perinatal exposure disrupted intrinsic uterine pathways involved in endometrial proliferation and glandular function, providing a plausible mechanism for glyphosate-induced implantation failure by compromising uterine receptivity. Similar effects between GBH and Gly suggest the active principle mainly drives the adverse outcomes.

Novel protective aspects of dietary polyphenols against pesticidal toxicity and its prospective application in rice-fish mode: A Review

The rice fish system represents an innovative and sustainable approach to integrated farming, combining rice cultivation with fish rearing in the same ecosystem. However, one of the major challenges in this system is the pesticidal pollution resulting from various sources, which poses risks to fish health and overall ecosystem balance. In recent years, dietary polyphenols have emerged as promising bioactive compounds with potential chemo-preventive and therapeutic properties. These polyphenols, derived from various plant sources, have shown great potential in reducing the toxicity of pesticides and improving the health of fish within the rice fish system. This review aims to explore the novel aspects of using dietary polyphenols to mitigate pesticidal toxicity and enhance fish health in the rice fish system. It provides comprehensive insights into the mechanisms of action of dietary polyphenols and their beneficial effects on fish health, including antioxidant, anti-inflammatory, and detoxification properties. Furthermore, the review discusses the potential application methods of dietary polyphenols, such as direct supplementation in fish diets or through incorporation into the rice fields. By understanding the interplay between dietary polyphenols and pesticides in the rice fish system, researchers can develop innovative and sustainable strategies to promote fish health, minimize pesticide impacts, and ensure the long-term viability of this integrated farming approach. The information presented in this review will be valuable for scientists, aqua-culturists, and policymakers aiming to implement eco-friendly and health-enhancing practices in the rice fish system.

High toxicity of agro-industrial wastewater on aquatic fauna of a South American stream: Mortality of aquatic turtles and amphibian tadpoles as bioindicators of environmental health

The aim of this study was to characterize an aquatic system of Santa Fe province (Argentina) receiving wastewater from agro-industrial activities (mainly dairy) by in situ assessment (fauna mortality, physicochemical, microbiological, and pesticide residues measurement), and ecotoxicity bioassays on amphibian tadpoles. Water and sediment samples were obtained from the Los Troncos Stream (LTS), previous to the confluence with the "San Carlos" drainage channel (SCC), and from the SCC. Biological parameters (mortality and sublethal biomarkers) were used to evaluate ecotoxicity during 10-day exposure of Rhinella arenarum tadpoles to LTS and SCC samples. Nine pesticides were detected in both LTS and SCC. Chemical and biochemical oxygen demand, ammonia, and coliform count recorded in SCC greatly exceeded limits for aquatic life protection. At SCC and LTS after the confluence with SCC, numerous dying and dead aquatic turtles (Phrynops hilarii) were recorded. In the ecotoxicity assessment, no mortality of tadpoles was observed in LTS treatment, whereas total mortality (100%) was observed in SCC treatments in dilution higher than 50% of water and sediment. For SCC, median lethal concentration and the 95% confidence limits was 18.30% (14.71-22.77) at 24 h; lowest-observed and no-observed effect concentrations were 12.5% and 6.25%, respectively. Oxidative stress and neurotoxicity were observed in tadpoles exposed to 25% SCC dilution treatment. In addition, there was a large genotoxic effect (micronuclei test) in all sublethal SCC dilution treatments (6.25%, 12.5%, and 25%). These results alert about the high environmental quality deterioration and high ecotoxicity for aquatic fauna of aquatic ecosystems affected by agro-industrial wastewater. PRACTITIONER POINTS: Great mortality of turtles was observed in a basin with a high load of agro-industrial wastewater. San Carlos Channel (SCC), where effluents are spilled, is environmentally deteriorated. The water-sediment matrix of SCC caused 100% lethality in tadpoles. SCC dilutions caused neurotoxicity, oxidative stress, and genotoxicity on tadpoles.

Impacts of horticultural environments on Rhinella arenarum (Anura, Bufonidae) populations: exploring genocytotoxic damage and demographic life history traits

Horticulture poses a significant ecological risk, as agrochemicals are applied more frequently and in larger quantities per unit of production compared to extensive crop fields. The native amphibian Rhinella arenarum serves as a reliable bioindicator of environmental health. This study aimed to assess genocytotoxic damage and demographic life history traits of R. arenarum inhabiting horticultural environments. Sampling was conducted in suburban sites in central Argentina: H1 and H2 (sites associated with horticultural activity) and a reference site, RS. Environmental parameters were recorded, and the frequency of micronuclei (Mn), nuclear abnormalities (ENA), and indicators of cytotoxic damage were determined in tadpoles and adults. Demographic variables (age at maturity, longevity, potential reproductive lifespan, size at maturity, modal lifespan) were calculated. The highest nitrate and phosphate values, along with low dissolved oxygen values, were recorded at sites H1 and H2. Organisms inhabiting horticultural environments exhibited higher frequencies of Mn and ENA, surpassing those recorded in previous studies on tadpoles from sites with extensive crop production. Size at maturity and age at maturity of females, as well as size at maturity, longevity, mean age, and mean adult SVL of males, were lower in horticultural sites. The results support the hypothesis that anuran populations inhabiting horticultural environments demonstrate a diminished health status attributed to subpar environmental quality. Monitoring endpoints at different biological levels provides information on the ecotoxicological risk for amphibians and human populations inhabiting nearby areas.

Construction of CuO/Fe2O3 Nanozymes for Intelligent Detection of Glufosinate and Chlortetracycline Hydrochloride

In this work, CuO/Fe2O3 nanozymes with high peroxidase-like activity were synthesized by using hydrothermal and calcination methods. The high-resolution transmission electron microscopy (HRTEM) proved that the heterogeneous interface of CuO/Fe2O3 was the main reason for the high enzyme-like activity. Strong interactions of CuO and Fe2O3 were successfully verified by X-ray absorption near-edge structure (XANES) characterization. Experiments and density functional theory (DFT) calculations were also used to explain the increased enzyme activity. The heterogeneous interface acted as the main active center, facilitating the electron transfer from CuO to Fe2O3. A colorimetric and intelligent sensing system was constructed based on deep learning. Using the peroxidase-like activity of CuO/Fe2O3, a platform for glufosinate pesticides and chlortetracycline hydrochloride (CTC) with the signal "on-off-on" changes were established. The limit of detection (LOD) of glufosinate and CTC was 28 and 0.69 μM, respectively. It was successfully applied in the detection of environmental water and soil. This study can provide an intelligent detection method for environmental monitoring.