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The Chinese tapertail anchovy, Coilia nasus, is a socioeconomically important anadromous fish that migrates from near ocean waters to freshwater to spawn every spring. The analysis of genomic architecture and information of C. nasus were hindered by the previously released versions of reference genomes with gaps. Here, we report the assembly of a chromosome-level gap-free genome of C. nasus by incorporating high-coverage and accurate long-read sequence data with multiple assembly strategies. All 24 chromosomes were assembled without gaps, representing the highest completeness and assembly quality. We assembled the genome with a size of 851.67 Mb and used BUSCO to estimate the completeness of the assembly as 92.5%. Using a combination of de novo prediction, protein homology and RNA-seq annotation, 21,900 genes were functionally annotated, representing 99.68% of the total predicted protein-coding genes. The availability of gap-free reference genomes for C. nasus will provide the opportunity for understanding genome structure and function, and will also lay a solid foundation for further management and conservation of this important species. Measurement(s) Coilia nasus • Gap-free genome assembly • sequence annotation Technology Type(s) DNBSEQ • Pacbio HiFi Sequencing • Nanopore Sequencing • Hi-C Sample Characteristic - Organism Coilia nasus Sample Characteristic - Environment freshwater Sample Characteristic - Location Taizhou City, Jiangsu Province, China [ABSTRACT FROM AUTHOR]

Simple Summary: Nile tilapia (Oreochromis niloticus) as one of the main commercially cultivated fishes in China, is plagued by liver diseases caused by some stressors. Salvianolic acid B (Sal B) has the strongest antioxidant effect and has a good protective effect on the liver. The objective of this study is to evaluate the protective effect of Sal B on oxidative hepatic injury in Nile tilapia, followed by assessing the potential protective mechanism. Our experimental data show that Sal B can not only directly reduce the level of reactive oxygen species (ROS), but can also resist CTX-induced oxidative injury by adjusting the autophagy and apoptosis levels of hepatocytes. Notably, the hepatoprotective effect of Sal B on Nile tilapia is related to the regulation of Nrf2, AMPK/mTOR and MAPK pathways. The research will lay the foundation for the application of Sal B in tilapia culture. Salvianolic acid B (Sal B), as one of the main water-soluble components of Salvia miltiorrhizae, has significant pharmacological activities, including antioxidant, free radical elimination and biofilm protection actions. However, the protective effect of Sal B on Nile tilapia and the underlying mechanism are rarely reported. Therefore, the aim of this study was to evaluate the effects of Sal B on antioxidant stress, apoptosis and autophagy in Nile tilapia liver. In this experiment, Nile tilapia were fed diets containing sal B (0.25, 0.50 and 0.75 g·kg−1) for 60 days, and then the oxidative hepatic injury of the tilapia was induced via intrapleural injection of 50 g·kg−1 cyclophosphamide (CTX) three times. After the final exposure to CTX, the Nile tilapia were weighed and blood and liver samples were collected for the detection of growth and biochemical indicators, pathological observations and TUNEL detection, as well as the determination of mRNA expression levels. The results showed that after the CTX treatment, the liver was severely damaged, the antioxidant capacity of the Nile tilapia was significantly decreased and the hepatocyte autophagy and apoptosis levels were significantly increased. Meanwhile, dietary Sal B can not only significantly improve the growth performance of tilapia and effectively reduce CTX-induced liver morphological lesions, but can also alleviate CTX-induced hepatocyte autophagy and apoptosis. In addition, Sal B also significantly regulated the expression of genes related to antioxidative stress, autophagy and apoptosis pathways. This suggested that the hepatoprotective effect of Sal B may be achieved through various pathways, including scavenging free radicals and inhibiting hepatocyte apoptosis and autophagy. [ABSTRACT FROM AUTHOR]

Anisakidae nematode larvae is one of the most common parasites in wild anadromous Coilia nasus. This study aims to explore the mechanism of the C. nasus immune response to the parasitism of Anisakid nematode larvae. Results found that Anisakid nematode larvae parasitism caused liver injury as evidenced by histomorphology results as well as high levels of aminotransferase and aspertate aminotransferase. Furthermore, Anisakid nematode larvae parasitism induced an immune response in the host, which was characterized by the elevated populations of macrophages and neutrophils in the liver and head‐kidney in the Anisakidae‐infected group compared to the noninfected group. The expression of immunoglobulin IgM and IgD in the liver and head‐kidney was also increased in the Anisakidae‐infected group. The Anisakidae‐infected group showed higher activity of antioxidant enzymes catalase and superoxide dismutase, which indicates severe oxidative stress, and increased production of pro‐inflammatory cytokines, TNF‐α, IL‐6 as well as MCP‐1 in the liver compared with the noninfected group. As a result of inflammation, livers of hosts in the Anisakidae‐infected group showed fibrosis, and elevated expression of associated proteins including α‐smooth muscle actin, fibronectin, collagen type I and type III compared with the noninfected group. We demonstrated that Anisakid nematode larvae parasitism results in injury and fibrosis in the liver, and triggers immune cell infiltration and inflammation in the liver and head‐kidney of C. nasus. Altogether, the results provide a foundation for building an interaction between parasite and host, and will contribute to C. nasus population and fishery resource protection. [ABSTRACT FROM AUTHOR]

The research on logistics heat facilitates the understanding of the drivers of regional logistics development. However, many scholars ignore the difference between prediction methods in terms of attributes and focal points of data analysis during the selection of regional logistics heat prediction model. Regional logistics interacts with regional economy. However, the studies on the coupling development between the two systems fail to make a detailed analysis in the light of their actual situation. Therefore, the evaluation of the coordination degree is often biased. To solve the problem, this paper probes into the prediction of regional logistics heat and the coupling development between regional logistics and economic systems. Firstly, an index system was established to measure the level of coupling development between the two systems, and a grey relational analysis was performed on the indices, leading to the evaluation results on coordination degree. Next, a composite model of GM (1, 1) and backpropagation (BP) neural network was proposed, and the deviation interval of the composite predictions was predicted based on Markov chain prediction model. The proposed algorithm proved effective through experiments. [ABSTRACT FROM AUTHOR]

Streptococcosis, a bacterial disease for multiple fish species, especially tilapia, caused more disruption to the fish culture industry. However, the underlying mechanisms for the occurrence of streptococcosis remain unclear. The aim of this study was to study the effects of streptococcus on the liver of tilapia. In this study, tilapia were injected streptococcal solution (0.05 ml/10 g body weight) and collected blood and liver at 4, 8, 24, 48, 72, 96, 120 and 144 hr after injection. The results showed that the activities of glutamate oxalate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (AKP) and superoxide dismutase (SOD) in the serum of tilapia exhibited irregular changes: increase at first, then decrease and increase again. The levels of total antioxidant capacity (T‐AOC), glutathione (GSH) and malondialdehyde (MDA) showed a decreasing tendency in serum after injection, except GSH at 4 hr. The activity of catalase (CAT) decreased in serum at 4, 24, 120 and 144 hr after injection of streptococcal solution, while the content TP enhanced in serum at 48, 72 and 120 hr after injection. Observations of pathological sections showed obvious damage to the liver tissue structure in response to streptococcal infection. Western blotting revealed an increase in ikkbeta (Ikkβ) protein with prolonged infection time and a decrease in NF‐kappa‐B inhibitor alpha (IkB‐α) and ikappab kinase alpha (Ikkα) proteins. The gene expression of cytochrome P4501A (CYP1A) was downregulated in liver at 24 and 48 after injection, while the mRNA levels of heat stress protein 70 (HSP70) and tumour necrosis factor alpha (TNF‐α) increased at 48 and/or 72 hr. Taken together, our findings confirmed that streptococcus can cause serious damage to the liver of tilapia. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the hepatoprotective effects of Angelica sinensis extract (ASE) against carbon tetrachloride (CCl4)-induced hepatotoxicity in Jian carp ( Cyprinus carpio var.Jian). Fish were fed diets containing four doses of ASE (0%, 0.1%, 0.5% and 1.0%) for 60 days, and then given an intraperitoneal injection of 30% CCl4 in olive oil at a volume of 0.05 mL/10 g body weight. At 72 h post injection, blood and liver samples were collected for biochemical analysis, comet assay, histopathological examination and CYP3A mRNA expression. Results showed that the increases of glutamate pyruvate transaminase (GPT) and glutamate oxalate transaminase (GOT) induced by CCl4 were significantly inhibited by pre-treating the fish with 0.1%, 0.5% and 1.0% ASE in the diets. The elevation of lactate dehydrogenase (LDH) and the reductions of the total protein (TP) and albumin (Alb) in the serum induced by CCl4 were also inhibited by pre-treatments with 0.5 and 1.0% ASE. In the liver tissue, pre-treatment with 1.0% ASE significantly inhibited the malondialdehyde (MDA) formation and the reductions of the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH) and CYP3A mRNA expression induced by CCl4. Comet assay showed that tail moment, olive tail moment, tail length and tail DNA% were positively changed in fish pretreated with 0.5 and 1.0% ASE. CCl4-induced histological changes were obviously reduced by 0.5% and 1.0% ASE. Overall results prove the hepatoprotective effect of ASE in a dose-dependent manner and support the use of ASE (1.0%) as a hepatoprotective and antioxidant agent in fish. [ABSTRACT FROM AUTHOR]

A Ty3/gypsy-retrotransposon-type transposon was found in the genome of the Jian carp ( Cyprinus carpio var. Jian) in a previous study (unpublished), and was designated a JRE retrotransposon (Jian retrotransposon). The full-length JRE retrotransposon is 5126 bp, which includes two long terminal repeats of 470 bp at the 5′ end and 453 bp at the 3′ end, and two open reading frames between them: 4203 bp encoding the group-specific antigen (GAG) and polyprotein (POL). The pol gene has a typical Ty3/gypsy retrotransposon structure, and the gene order is protease, reverse transcriptase, RNase H, and integrase (PR-RT-RH-IN). A phylogenetic analysis of the pol gene showed that it has similarities of 40.7, 40, and 32.8 %, to retrotransposons of Azumapecten farreri, Mizuhopecten yessoensis, and Xiphophorus maculatus, respectively. Therefore, JRE might belong to the JULE retrotransposon family. The copy number of the JRE transposon in the genome of the Jian carp is 124, determined with real-time quantitative PCR. The mRNA of the JRE retrotransposon is expressed in five Jian carp tissues, the liver, kidney, blood, muscle, and gonad, and slightly higher in the kidney and liver than in the other tissues. [ABSTRACT FROM AUTHOR]

The estuarine tapertail anchovy, Coilia nasus , is an anadromous fish that undertakes over a 600-km spawning migration along the Yangtze River of China. They generally cease feeding during this process, but we recently documented that a small proportion of them appear to feed. Research on proteomic responses is essential for understanding the phenomenon of C. nasus feeding. In this study, we used an iTRAQ-based proteomics approach to study the changes in protein expression in response to food intake in C. nasus following voluntary fasting. Coilia nasus in the feeding group (CSI) were fed shrimp or small fish, whereas those in the control group (CSN) were starved. We identified 3279 proteins in the gastric tissue/stomach, of which 279 were significantly differentially expressed. In all, 133 differentially expressed proteins (DEPs) were upregulated and 146 proteins were downregulated in CSI compared with those in CSN C. nasus. In addition to gastric acid secretion caused by gastric distention, a functional analysis suggested that a series of DEPs were involved mainly in the regulation of protein digestion (e.g., carboxypeptidase A1 and chymotrypsin A-like), immune response (e.g., lysozyme and alpha 2-macroglobulin), and nutrition metabolism (e.g., glyceraldehyde 3-phosphate dehydrogenase, glycogenin, long-chain acyl-CoA synthetase, and creatine kinase). Real-time PCR confirmed that the mRNA levels of the DEPs were similar those obtained using iTRAQ. These results indicate that the nutrients obtained through food were effectively utilized by C. nasus , thereby providing energy for swimming, gonadal maturation, primary metabolism, and an enhanced immune function to better resist pathogen interference. This research contributes to the elucidation of nutritional regulation mechanisms of C. nasus to better protect the wild population. [Display omitted] • A comprehensive iTRAQ-based proteome of the stomachs of C. nasus was obtained. • A large number of DEPs related to nutrition metabolism were identified. • Some key proteins related to immune response were differentially expressed. • Fatty acid β-oxidation provides energy for spawning migration and gonadal development of C. nasus. [ABSTRACT FROM AUTHOR]

1. Cytochrome P450s are the major metabolizing enzymes for xenobiotics in humans and other mammals. Although the domestic cat Felis catus, an obligate carnivore, is the most common companion animal, the properties of cytochrome P450 subfamilies are largely unknown. 2. We newly identified the feline CYP2A13, which consists of 494 deduced amino acids, showing the highest identity to CYP2As of dogs, followed by those of pigs, cattle and humans. 3. The feline CYP2A13 transcript and protein were expressed almost exclusively in the liver without particular sex-dependent differences. 4. The feline CYP2A13 protein heterogeneously expressed in Escherichia coli showed metabolic activity similar to those of human and canine CYP2As for coumarin, 7-ethoxycoumarin and nicotine. 5. The results indicate the importance of CYP2A13 in systemic metabolism of xenobiotics in cats. [ABSTRACT FROM AUTHOR]

Highlights: [•] CO2 adsorption capacity of AC depends on pores of <0.7nm under PSA condition. [•] The oxygen-containing surface groups on AC have little effect on CO2 adsorption. [•] Ash in bio-ACs, exactly K compound, has a positive effect on CO2 adsorption. [•] The ash in coal-AC, Ca, Si, Al and Fe compounds, are inert to CO2 adsorption. [Copyright &y& Elsevier]

Abstract: CO2 separation from flue gas with activated carbon (AC) as the adsorbent has received much attention and pressure swing adsorption (PSA) is considered to be a promising method for its application. Dynamic adsorption of CO2 simulates PSA operation and has been gradually adopted in laboratory study in recent years. The most important AC index determined in the studies is excess adsorption capacity of CO2, which is, however, prone to error frequently due to improper analysis of CO2 accumulated in the void spaces of the experimental setup and the packed pellets. The influence of N2, the major component in flue gases, on CO2 adsorption was also not fully studied in the literature. This work presents a detailed study on these issues at the typical PSA conditions, CO2 pressures of 0.01–0.20MPa and adsorption temperatures of 273.0–303.0K. Results show that, in comparison to the excess adsorption capacity of CO2, the amounts of CO2 accumulated in the gap space between AC pellets and the pores space in AC pellets are usually small and can be neglected, but that in the system dead space is large and can not be neglected especially for small experimental setups. A general equation is proposed to determine the amount of CO2 in the system dead space at different operating conditions. N2 has little influence on the excess adsorption capacity of CO2 under the conditions used in this work. [Copyright &y& Elsevier]

Silymarin, a mixture of bioactive flavonolignans from the milk thistle ( Silybum marianum), is traditionally used in herbal medicine to defend against various hepatotoxic agents. The aim of the present study was to evaluate the protective effect of silymarin against carbon tetrachloride (CCl)-induced liver injury in fish. Common carp, with an average initial weight of 17.0 ± 1.1 g, were fed diet containing four doses of silymarin (0, 0.1, 0.5, and 1 g/kg diet) for 60 d. Fish were then given an intraperitoneal injection of CCl (30% in arachis oil) at a dose of 0.5 ml/kg body weight. At 72 h after CCl injection, blood and liver samples were collected for the analyses of serum biochemical parameters, liver index, peroxidation product, glutathione, and antioxidant enzyme activities. The results showed that administration of silymarin at 0.5 and 1 g/kg diet for 60 d prior to CCl intoxication significantly reduced the elevated activities of glutamate pyruvate transaminase, glutamate oxalate transaminase, lactate dehydrogenase (LDH), and increased the reduced levels of total protein and albumin in the serum. The reduced levels of liver index, superoxide dismutase, glutathione peroxidase, catalase, glutathione, and total antioxidant capacity were markedly increased, and malondialdehyde formation was significantly restrained in the liver. However, these parameters, except LDH, were not significantly changed in fish fed with silymarin at 0.1 g/kg diet. Based on the results, it can be concluded that silymarin has protective effect against CCl-induced hepatotoxicity in fish. It is suggested that silymarin may be used as a hepatoprotective agent to prevent liver diseases in fish. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H 2 O 2), as a common disinfectant, has been extensively used in aquaculture. The toxicity of high ambient H 2 O 2 for gills and liver of fish has received attention from many researchers. However, whether H 2 O 2 exposure induced brain injury and neurotoxicity has not been reported in fish. Therefore, this study aimed to explore the potential mechanism of H 2 O 2 toxicity in brain of common carp via transcriptome analysis and biochemical parameter detection. The fish were exposed to 0 (control) and 1 mM of H 2 O 2 for 1 h per day lasting 14 days. The results showed that H 2 O 2 exposure caused oxidative damage in brain evidenced by decreased glutathione (GSH), total antioxidant capacity (T-AOC) and nicotinamide adenine dinucleotide (NAD+) levels, and increased formation of malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OHdG). Meanwhile, H 2 O 2 exposure reduced 5-hydroxytryptamine (5-HT) level, and down-regulated tryptophan hydroxylase 1 (tph1a), tph2 , 5-hydroxytryptamine receptor 1A-beta (htr1ab) and htr2b expression in brain. Transcriptome analysis showed that H 2 O 2 exposure up-regulated 604 genes and down-regulated 1209 genes in brain. Go enrichment displayed that the differently expressed genes (DEGs) were enriched mainly in cellular process, single-organism process, metabolic process, and biological regulation in the biological process category. Further, KEGG enrichment indicated that H 2 O 2 exposure led to dysregulation of neurotransmitter signals including depression of glutamatergic synapse, GABAergic synapse and endocannabinoid signaling. Also, we found the alteration of three key pathways including calcium, cAMP and HIF-1 in brain after H 2 O 2 exposure. In conclusion, our data indicated that H 2 O 2 exposure induced oxidative damage and neurotoxicity, possibly related to dysregulation of neurotransmitters and calcium, cAMP and HIF-1 signaling pathways, which may adversely affect learning, memory and social responses of common carp. This study provided novel insight into biological effects and underlying mechanism of H 2 O 2 toxicity in aquatic animal, and contributed to proper application of H 2 O 2 in aquaculture. [Display omitted] • Hydrogen peroxide exposure causes oxidative damage in brain of common carp. • Hydrogen peroxide exposure results in 604 up- and 1209 down-regulated genes. • Dysregulation of neurotransmitters are involved in the brain injury. • Three key signaling pathways regulating neurological function are altered. [ABSTRACT FROM AUTHOR]

Abstract: The effect of two Chinese herbs (Astragalus radix and Scutellaria radix) on non-specific immune response of tilapia, Oreochromis niloticus, was investigated. Three-month-old tilapia with an average initial weight of 62.8±5.40 g were fed diets containing four doses of Astragalus radix (0; 0.1; 0.5 and 1.0%) and four doses of Scutellaria radix (0; 0.1; 0.5 and 1.0%) for 4 weeks. Respiratory burst activity (extracellular superoxide anion production), phagocytosis by isolated blood leukocytes (neutrophils and monocytes) and lysozyme activity in plasma were investigated 1, 2, 3 and 4 weeks after feeding. Both Astragalus radix and Scutellaria radix can modulate the innate immune system of tilapia. The results of this study showed that feeding tilapia with 0.1 and 0.5% Astragalus radix for 1 week enhanced lysozyme activity and for 3 weeks stimulated phagocytosis by phagocytic blood cells, however, respiratory burst activity of phagocytic cells was not increased. On the other hand, inhibition of phagocytosis and respiratory burst activity was found when tilapia was fed with medium and high doses of Scutellaria radix, but not lysozyme activity. There were no significant differences among groups fed with different doses of both herbs. The optimal doses of Astragalus were 0.1% and 0.5% with an optimal feeding period of 3 weeks. Further work is needed to establish the stimulatory dose and optimal time of feeding of Scutellaria. [Copyright &y& Elsevier]

Bisphenol A (BPA), as a phenolic compound, is harmful to human health, and its residue in the aquatic environment also threatens the health of aquatic animals. In this research, the toxicity effects of BPA on liver tissues were evaluated in common carp (Cyprinus carpio) after long-term exposure. Fish were exposed to five concentrations of BPA (0, 0.01, 0.1, 0.5 and 2 mg/L) for 30 days. The blood and liver tissues were gathered to analyze biochemical indices and genes transcription levels. The data related to lipid metabolism showed that BPA exposure increased serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) levels, upregulated the expressions of fatp1 , pparγ , fas , atgl , hsl , pparα , cpt1b , acox-1 , and downregulated the expression of dgat1 in liver. Antioxidative parameters displayed a reduced antioxidant ability and increased lipid peroxidation after BPA exposure. Meanwhile, the upregulations of nrf2 , ho-1 , cyp1a and cyp1b genes revealed an adaptive response mechanism against oxidative stress-induced adverse effects. After 30 days of exposure, BPA induced apoptosis and endoplasmic reticulum stress (ERS) via upregulating the expression levels of apoptosis and ERS-related genes and increasing Ca2+ concentration in liver. Moreover, the downregulation of mtor and the upregulation of atg3 , atg7 , tfeb , uvrag and mcoln1 indicated that BPA could influence the normal process of autophagy. Furthermore, BPA exposure activated toll like receptors (TLRs) pathway to mediate the inflammatory response. Our results demonstrated that BPA exposure disturbed lipid metabolism, and induced oxidative stress, ERS, apoptosis, autophagy and inflammatory response in the liver of common carp. These findings contributed to the understanding of hepatotoxicity mechanism induced by BPA in fish. • New insights into how bisphenol A affects fish physiological responses were provided. • Bisphenol A influenced the lipid metabolism in common carp liver. • Nrf2/HO-1 pathway was involved in bisphenol A-induced oxidative stress. • Bisphenol A altered endoplasmic reticulum stress, autophagy and apoptosis. • Bisphenol A induced inflammatory responses via initiating TLRs/MyD88 pathway. [ABSTRACT FROM AUTHOR]

Radix Bupleuri extract (RBE) is one of the most popular oriental herbal medicines, which has anti-oxidative and anti-inflammatory properties. However, its protective effects and underlying molecular mechanisms on oxidative damage in tilapia are still unclear. The aims of the study were to explore the anti-oxidative, anti-inflammatory and hepatoprotective effects of RBE against oxidative damage, and to elucidate underlying molecular mechanisms in fish. Tilapia received diet containing three doses of RBE (0, 1 and 3 g/kg diet) for 60 days, and then were given an intraperitoneal injection of H 2 O 2 or saline. Before injection, RBE treatments improved growth performance and partial anti-oxidative capacity in tilapia. After oxidative damage, RBE pretreatments were able to signally reduce the higher serum aminotransferases, alkaline phosphatase (AKP) and liver necrosis. In serum and liver, the abnormal lipid peroxidation level and antioxidant status induced by H 2 O 2 injection were restored by RBE treatments. Furthermore, RBE treatments activated erythroid 2-related factor 2 (Nrf2) signaling pathway, which promoted the gene expression of heme oxygenase 1 (HO-1), NAD(P) H:quinone oxidoreductase 1 (NQO-1), glutathione-S-transferase (GST) and catalase (CAT). Meanwhile, RBE treatments reduced inflammatory response by inhibiting TLRs-MyD88-NF-κB signaling pathway, accompanied by the lower interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-8 mRNA levels. In addition, RBE treatments upregulated complement (C3) gene expression and downregulated heat shock protein (HSP70) gene expression. In conclusion, the current study suggested that RBE pretreatments protected against H 2 O 2 -induced oxidative damage in tilapia. The beneficial activity of RBE may be due to the modulation of Nrf2/ARE and TLRs-Myd88-NF-κB signaling pathway. • RBE exerts anti-oxidative, anti-inflammatory and hepatoprotective effects against liver injury in fish. • RBE activities Nrf2 signaling pathway to improve antioxidant defense. • RBE inhibits TLRs-MyD88-NF-κB signaling pathway to ameliorate inflammatory response. [ABSTRACT FROM AUTHOR]

Abstract Oxidative stress has been implicated in the pathogenesis of many liver diseases in fish, but the molecular mechanism is still obscure. Here, we used hydrogen peroxide (H 2 O 2) as a reactive oxygen species (ROS) to induce liver injury and assess underlying molecular mechanism linking oxidative stress and liver injury in fish. Tilapia were injected with various concentrations of H 2 O 2 (0, 40, 120, 200, 300 and 400 mM) for 72 h. The blood and liver were collected to assay biochemical parameters and genes expression after 24, 48 and 72 h of injection. The results showed that treatments with higher H 2 O 2 levels (300 and/or 400 mM) significantly increased the levels of GPT, GOT, AKP and MDA, and apparently decreased the levels of TP, ALB, SOD, GSH, CAT, GST and T-AOC throughout of the 72 h. The gene expression data showed that treatments with 200, 300 and/or 400 H 2 O 2 suppressed Nrf2/keap1 pathway and its downstream genes including ho-1 , nqo1 and gsta , activated inflammatory response via enhancing the mRNA levels of nf-κb , tnf-α , il-1β and il-8 , and attenuating il- 10 mRNA level, and caused immunotoxicity through downregulating the genes expression of c3 , hep, lzm and Igm for 24, 48 and/or 72 h. Additionally, there was a mild or strong increase in levels of nrf2 and its subsequent antioxidant genes or enzymes such as ho-1 , nqo1 , gst , CAT and SOD in treatments with lower concentrations of H 2 O 2 (40 or 120 mM) for 24 and/or 48 h. Overall results suggested that H 2 O 2 hepatotoxicity was mainly concerned with lipid peroxidation, impairment antioxidant defense systems, inflammatory response and immunotoxicity, and Nrf2/Keap1 and NF-κB signaling pathways played important roles in oxidative stress-induced liver injury in fish. Graphical abstract Image 1 Highlights • High H 2 O 2 induced inflammation response and immunotoxicity in liver of tilapia. • High H 2 O 2 suppressed the Nrf2/Keap1 signaling pathway. • High H 2 O 2 activated NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]