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Microplastic pollution poses challenges for ecosystems worldwide, and nanoplastics (NPs, 1-1000 nm) have been identified as persistent pollutants. However, although some studies have described the hazards of NPs to aquatic organisms, the toxicological processes of NPs in the common carp kidney and the biotoxicity of differently sized NPs remain unclear. In this study, we used juvenile common carp as an in vivo model that were constantly exposed to freshwater at 1000 μg/L polystyrene nanoparticle (PSNP) concentrations (50, 100, and 400 nm) for 28 days. Simultaneously, we constructed an in vitro model utilizing grass fish kidney cells (CIK) to study the toxicological effects of PSNPs of various sizes. We performed RT-PCR and Western blot assays on the genes involved in FOXO1, HMGB1, HIF-1α, endoplasmic reticulum stress, autophagy, and immunoreaction. According to these results, exposure to PSNPs increased reactive oxygen species (ROS) levels, and the carp kidneys experienced endoplasmic reticulum stress. Additionally, PSNPs promoted renal autophagy by activating the ROS/ERS/FOXO1 (ERS: endoplasmic reticulum stress) pathway, and it affected immunological function by stimulating the ROS/HMGB1/HIF-1α signaling pathway. This study provides new insights into the contamination hazards of NPs in freshwater environments, as well as the harm they pose to the human living environments. The relationship between particle size and the degree of damage caused by PSNPs to organisms is a potential future research direction., Competing Interests: Declaration of competing interest The authors have announced no conflict of interest. All authors have read the manuscript and consented to submit it in its current form for consideration for publication in the Journal., (Copyright © 2024. Published by Elsevier Ltd.)

Chlorpyrifos (Diethoxy-sulfanylidene-(3,5,6-trichloropyridin-2-yl) oxy-λ 5 -phosphane, CPF) was extensively used organophosphorus pesticide, extensively deteriorating public problem with the enrichment in the water bodies. Eucalyptol (1,3,3-Trimethyl-2-oxabicyclo[2.2.2] octane, EUC), a colorless cyclic monoterpene oxide, has shown anti-inflammatory and anti-oxidation properties. To explore the effect of EUC on CPF-induced necroptosis in the grass carp liver cells (L8824 cells), we treated L8824 cells with 60 mM CPF and 5 μM EUC for 24 h. The results showed that CPF exposed lead to excessive accumulation of reactive oxygen species (ROS) and oxidative stress, activating the NF-κB and RIPK1 pathway, increasing the level of cell necroptosis. However, EUC treatment attenuated the toxic effects of CPF treatment on L8824 cells. In summary, the study demonstrated that CPF induced necroptosis and inflammation, and EUC treatment could decrease CPF-caused cell injury., Competing Interests: Declaration of Competing Interest The authors have announced no conflict of interest. All authors have read the manuscript and consented to submit it., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The wide application of Avermectin (AVM) has caused pollution of surface water and damage to non-target organisms. A growing body of evidence supports the most prominent role of Eucalyptol (EUC) is antioxidation. To the purpose of explore the injury mechanism of Avermectin on grass carp hepatocytes and the antagonistic effect of Eucalyptol, 5.7 μM AVM and/or 20 μM EUC were used to treat grass carp hepatocytes for 24 h to establish hepatocyte exposure model. The results showed that Avermectin exposure significantly increased the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in cells, reduced the activities of superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC). Also, the expressions of NLRP3 inflammasome-related genes including NLRP3, ASC, and Caspase-1, the necroptosis-related genes including RIPK1, RIPK3, and MLKL and apoptotic genes including Bax, Caspase-3, and Caspase-9 were all up-regulated. Meanwhile, the expressions of Caspase-8 and Bcl-2 were significantly decreased upon exposure to Avermectin. However, the toxicity was significantly alleviated with the treatment of EUC or N-acetyl-l-cysteine (NAC). The above results indicated that eucalyptol alleviated AVM exposure-induced apoptosis and necroptosis of grass carp hepatocytes by regulating the ROS/NLRP3 signaling pathway., Competing Interests: Declaration of Competing Interest All authors have no disputes of interest in this experiment., (Copyright © 2023. Published by Elsevier B.V.)

As an environmental pollutant, profenofos (PFF) can seriously endanger human health through the food chain. Albicanol is a sesquiterpene compound with antioxidant, anti-inflammatory, and anti-aging properties. Previous studies have shown that Albicanol can antagonize apoptosis and genotoxicity caused by PFF exposure. However, the toxicity mechanism of PFF regulating hepatocyte immune function, apoptosis, and programmed necrosis and the role of Albicanol in this process have not been reported yet. In this study, grass carp hepatocytes (L8824) were treated with PFF (200 μM) or combined with Albicanol (5 ×10 -5 μg mL -1 ) for 24 h to establish an experimental model. The results of JC-1 probe staining and Fluo-3 AM probe staining showed increased free calcium ions and decreased mitochondrial membrane potential in L8824 cells after PFF exposure, suggesting that PFF exposure may lead to mitochondrial damage. Real-time quantitative PCR and Western blot results showed that PFF exposure could increase the transcription of innate immunity-related factors (C3, Pardaxin 1, Hepcidin, INF-γ, IL-8, and IL-1β) in L8824 cells. PFF up-regulated the TNF/NF-κB signaling pathway and the expression of caspase-3, caspase-9, Bax, MLKL, RIPK1, and RIPK3 and down-regulated the expression of Caspase-8 and Bcl-2. Albicanol can antagonize the above-mentioned effects caused by PFF exposure. In conclusion, Albicanol antagonized the mitochondrial damage, apoptosis, and necroptosis of grass carp hepatocytes caused by PFF exposure by inhibiting the TNF/NF-κB pathway in innate immunity., Competing Interests: Declaration of Competing Interest The authors claim that none of the material in the paper has been published or is under consideration for publication elsewhere. ALL other Authors have read the manuscript and have agreed to submit it in its current form for consideration for publication in the Journal. And there is no conflict of interest., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Atrazine (ATR) is a commonly used triazine herbicide, which will remain in the water source, soil and biological muscle tissue for a long time, threatening the survival of related organisms and future generations. Tannic acid (TAN), a glucosyl compound found in gallnuts, has previously been shown to antagonize heavy metal toxicity, antioxidant activity, and inflammation. However, it is unclear whether TAN can antagonize ATR-induced Grass carp hepatocytes (L8824 cells) cytotoxicity. Therefore, we treated L8824 cells with 3 μg mL -1  ATR for 24 h to establish a toxic group model. The experimental data of flow cytometry and AO/EB staining together showed that the ratio of apoptosis and necrosis in L8824 cells after ATR exposure was significantly higher than that in the control group. Furthermore, RT-qPCR showed that inflammatory factors (TNF-α, IL-1β, IL-6, INF-γ) were up-regulated and antimicrobial peptides (hepcidin, β-defensin and LEAP2) were induced down-regulated in L8824 cells, leading to immune dysfunction. The measurement results of oxidative stress-related indicators showed that the levels of ROS and MDA increased after ATR exposure, the overall anti-oxidative system was down-regulated. Western blotting confirmed that TNF-α/TNFR 1-related genes were also up-regulated. This indicates that ATR stimulates oxidative stress in L8824 cells, which in turn promotes the binding of TNF-α to TNFR 1. In addition, TRADD, FADD, Caspase-3, P53, RIP1, RIP3 and MLKL were found to be significantly up-regulated by Western blotting and RT-qPCR. Conditioned after ATR exposure compared to controls. It indicates that ATR activates apoptosis and necrosis of TNF-α/TNFR 1 pathway by inducing oxidative stress in L8824 cells. Furthermore, the use of TAN (5 μM) significantly alleviated the toxic effects of ATR on L8824 cells mentioned above. In conclusion, TAN restrains ATR-induced apoptosis, programmed necrosis and immune dysfunction through the ROS/TNF-α/TNFR 1 pathway., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Diisobutyl phthalate (DiBP), one of the commonly used plasticizers in industry, is an endocrine disruptor and environmental contaminant that can persist in water and threaten the health of aquatic creatures. Eucalyptol (Euc), a monoterpenoid extracted from plants, has been proved to have anti-inflammatory, antioxidant, and detoxification properties. However, the protective mechanism of Euc against cell injury caused by DiBP exposure and the involvement of apoptosis, autophagy, and immunity remains unknown. In the current investigation, 27.8 μg/mL DiBP or/and 20 μM Euc has been applied to Ctenopharyngodon idellus kidney (CIK) cells for 24 h. The findings showed that exposure to DiBP raised intracellular ROS levels, inducing oxidative stress, and enhanced the rate of apoptosis as well as the expression of the apoptotic markers Bax, Caspase3, Caspase9, and Cytc while decreasing the expression of Bcl-2. Furthermore, DiBP inhibited IL-2, IFN-γ, Hepcidin-1, and β-defensin expression and elevated TNF-α, and IL-1β levels, causing immune dysfunction. DiBP and Euc co-treatment significantly activated the Keap1/Nrf2/HO-1 pathway, restored antioxidant enzyme activity, and elevated autophagy pathway-associated genes ATG5, Beclin1, and LC3B decreased p62 expression, enhanced cell autophagy, reduced apoptosis, and improved immunity. In conclusion, Euc promotes autophagy, alleviates DiBP-induced apoptosis, and improves immunological dysfunction in CIK cells by regulating the Keap1/Nrf2/HO-1 pathway. These results demonstrated the threat of DiBP exposure to fish while providing a theoretical foundation for using Euc in aquaculture., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Nanoplastics (NPs) existing in aquatic ecosystem is an emerging environmental pollutant, which has become a nagging serious environmental problem. Miniaturized plastic fragments with different diameters have different penetration capabilities to body tissues, and thus may have different toxicity to the target organs. However, the specific toxicological effects and mechanisms of NPs with different particle sizes on aquatic animal hearts are still unknown. To this end, carps were directly exposed to the aqueous environment of polystyrene NPs (1000 μg/L, PS-NPs) with three particle sizes (50 nm, 100 nm and 400 nm), respectively, for 28 days. H&E and TUNEL staining displayed that exposed to PS-NPs of three diameters all caused myocardial tissue inflammation and cardiomyocyte apoptosis in carps. Of note, at the same exposure concentration, the damage caused by PS-NPs with particle size of 50 nm was more serious than that of 100 nm and 400 nm. Further research found that, in carp hearts exposed to PS-NPs, the levels of carp innate immunity-related components TLR4 and NOX2 were significantly higher than those in controls and were negatively correlated with the exposed particle size. The content of ROS increased significantly, the activities of antioxidant enzymes (CAT, SOD1 and Gpx1) decreased, and MDA accumulated. In addition, as the particle size of PS-NPs decreased, Th1 cells gradually replaced Th2 cells to dominate, the Th1/Th2 balance was dysregulated, and the expression of apoptosis-inducing pathway IGFBP3/p53/ACHE-related genes was increased, markedly. Overall, our study results demonstrated that PS-NPs exposure caused oxidative stress, resulting in inflammation and apoptosis in carp heart, and the degree of damage was negatively correlated with the particle size of PS-NPs. Our work enriched the theoretical basis for NPs toxicological research and shed new light on the risk of NPs exposure., (Copyright © 2022 Elsevier Ltd. All rights reserved.)