Characterization of zearalenone-induced hepatotoxicity and its mechanisms by transcriptomics in zebrafish model

Insights into the zearalenone degradation performance and pathway by Gordonia hydrophobica HAU421 and characterization of a novel lactonohydrolase involved

Zearalenone (ZEN) is a harmful macrolide mycotoxin, posing a serious hazard to human health. In this study, a highly efficient ZEN-degrading bacterium Gordonia hydrophobica HAU421 was isolated from soil by using spiramycin (SPM)-containing selective medium. Mass spectrometry analysis revealed that strain HAU421 could transform ZEN into hydrolyzed zearalenone (HZEN), zearalenol (ZEL), and hydrolyzed zearalenol (HZEL). A novel lactonohydrolase GhZH capable of hydrolyzing ZEN was mined from the genome of strain HAU421 and heterologously expressed in Escherichia coli. The recombinant GhZH exhibited peak activity at pH 7.0 and 42 °C. The catalytic triad of GhZH was identified as S122-D147-H297 via sequence comparison, molecular docking and site-directed mutagenesis. Moreover, toxicological analysis suggested that GhZH-catalyzed ZEN hydrolyzation resulted in the detoxification of its hepatotoxicity. To meet the industrial demands, GhZH was immobilized onto chitosan microspheres using the crosslinker glutaraldehyde. The stability of immobilized GhZH at harsh acidic pH and high temperature was enhanced in comparison with free GhZH. The immobilized GhZH achieved a ZEN removal rate of 53.2 % in beer and 74.0 % in corn steep liquor. These findings offer new insights into microbial ZEN degradation and support the advancement of enzyme-catalyzed ZEN detoxification.

Zearalenone induces liver injury in mice through ferroptosis pathway

Throughout the world, some foods and feeds commonly consumed by humans and animals are inadvertently contaminated with mycotoxins. Zearalenone (ZEA) is a typical environmental/food contaminant that can cause varying degrees of damage to the body, such as reproductive toxicity, hepatotoxicity, immunotoxicity, etc. It poses a serious threat to the living environment and human and animal health. Increasing evidence shows that mycotoxin-induced organ damage may be closely related to ferroptosis. However, the mechanism of ZEA-induced liver injury is still not fully understood. Therefore, this study aimed to explore whether ZEA can trigger ferroptosis in the liver and cause liver injury. This study was conducted by establishing in vivo and in vitro ZEA exposure models. The results showed that ZEA exposure led to typical liver injury indicators. ZEA inhibited the Nrf2/keap1 antioxidant signaling pathway, aggravated the oxidative stress response, and inhibited the body's antioxidant function. Additionally, it was found that ZEA can aggravate lipid peroxidation by blocking the system Xc-/GSH/GPX4 axis, upregulating the protein expression of ACSL4, and affecting the import, storage, and export of iron ions, thereby inducing iron ion metabolism disorders. A combination of multiple factors induces ferroptosis in mouse liver and AML12 cells. Pretreatment with deferoxamine, an inhibitor of ferroptosis, can alleviate ferroptosis damage induced by ZEA, indicating the crucial role of ferroptosis in cell damage caused by ZEA. This study deeply explores the hepatic ferroptosis pathway induced by ZEA, provides a new theoretical basis for ZEA-induced hepatotoxicity, and offers new insights for exploring potential treatment strategies.

Reversing Zearalenone Toxicity: The Role of Hydroxytyrosol in Zebrafish

Zearalenone (ZEA) is a widely distributed mycotoxin that presents a substantial worldwide health risk to animals. Several natural compounds have shown promise in mitigating the detrimental impacts of ZEA. This study examined the detoxification potential of previously identified compounds by utilizing zebrafish embryos as a model organism. Hydroxytyrosol stands out among these natural compounds. Our findings indicate that hydroxytyrosol effectively mitigated mortality, hatching delay, and phenotypic abnormalities induced by ZEA in the assessed embryos. Furthermore, hydroxytyrosol restored the frequency and intensity of tail coiling (TC) while decreasing the expression of heat shock proteins (HSPs) in the zebrafish embryos. Extended incubation with hydroxytyrosol demonstrated protective effects on zebrafish growth and morphology, muscle birefringence, and touch-evoked escape behavior. Subsequent investigations indicated that hydroxytyrosol reversed the expression of proapoptotic targets (e.g., bax and caspase8) and cell cycle regulators (e.g., p21, gadd45a, and rbl2), thereby mitigating apoptosis and G2 cell cycle arrest induced by ZEA in zebrafish embryos. Additionally, hydroxytyrosol decreased staining for senescence associated-β-galactosidase (SA-β-Gal). Notably, p53/FoxO pathway plays an important role in detoxification mechanisms. Overall, these novel findings highlight the potential of hydroxytyrosol to reverse ZEA-induced toxicity in multiple aspects. The mitigating effect of hydroxytyrosol on ZEA toxicity may have been underestimated.

Rutin, a natural flavonoid glycoside, ameliorates zearalenone induced liver inflammation via inhibiting lipopolysaccharide gut leakage and NF-κB signaling pathway in mice

Zearalenone (ZEN) poses a potential threat on human and animal health partly through the nuclear factor (NF)-κB signaling pathway. In silico study suggested that rutin effective against TLR4 and NF-κB. A wetting test was designed to evaluate the effect and underlying mechanism of rutin in alleviating ZEN-induced inflammation in animals. Twenty-four female mice were randomly divided into 4 groups: control (basal diet), ZEN group (basal diet + ZEN), rutin group (basic diet + rutin), Z + R group (basal diet + rutin + ZEN). Results showed that rutin effectively alleviated ZEN-induced inflammation and damage of liver and jejunum in mice. Rutin addition reduced the content of lipopolysaccharide (LPS) in serum and liver mainly by improving the intestinal barrier function resulted from the production increase of short-chain fatty acids (SCFA). In sum, this study showed that rutin alleviated ZEN-induced liver inflammation and injury by modulating the gut microbiota, increasing the production of SCFA and improving intestinal barrier function, leading to the decrease of LPS in liver and the inhibition of MyD88 independent NF-κB signaling pathway in mice. Specifically, these findings may provide useful insights into the screening of functional natural compounds and its action mechanism to alleviate ZEN induced liver inflammation.

The enhanced hepatotoxicity of isobavachalcone in depigmented zebrafish due to calcium signaling dysregulation and lipid metabolism disorder

Isobavachalcone (IBC) is a flavonoid component derived from Psoraleae Fructus that can increase skin pigmentation and treat vitiligo. However, IBC has been reported to be hepatotoxic. Current studies on IBC hepatotoxicity are mostly on normal organisms but lack studies on hepatotoxicity in patients. This study established the depigmented zebrafish model by using phenylthiourea (PTU) and investigated the difference in hepatotoxicity between normal and depigmented zebrafish caused by IBC and the underlying mechanism. Morphological, histological, and ultrastructural examination and RT-qPCR verification were used to evaluate the effects of IBC on the livers of zebrafish larvae. IBC significantly decreased liver volume, altered lipid metabolism, and induced pathological and ultrastructural changes in the livers of zebrafish with depigmentation compared with normal zebrafish. The RNA-sequencing and RT-qPCR results showed that the difference in hepatotoxicity between normal and depigmented zebrafish caused by IBC was closely related to the calcium signaling pathway, lipid decomposition and metabolism, and oxidative stress. This work delved into the mechanism of the enhanced IBC-induced hepatotoxicity in depigmented zebrafish and provided a new insight into the hepatotoxicity of IBC.

Curcumin alleviates zearalenone-induced liver injury in mice by scavenging reactive oxygen species and inhibiting mitochondrial apoptosis pathway

Curcumin (CUR) is a compound extracted from turmeric that has a variety of functions including antioxidant and anti-inflammatory. As an estrogen-like mycotoxin, zearalenone (ZEN) not only attacks the reproductive system, but also has toxic effects on the liver. However, whether CUR can alleviate ZEN-induced liver injury remains unclear. This paper aims to investigate the protective effect of CUR against ZEN-induced liver injury in mice and explore the molecular mechanism involved. BALB/c mice were randomly divided into control (CON) group, CUR group (200 mg/kg b. w. CUR), ZEN group (40 mg/kg b. w. ZEN) and CUR+ZEN group (200 mg/kg b. w. CUR+40 mg/kg b. w. ZEN). 28 d after ZEN exposure and CUR treatment, blood and liver samples were collected for subsequent testing. The results showed that CUR reversed ZEN-induced hepatocyte swelling and necrosis in mice. It significantly reduced the serum alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in mice (p < 0.05). In addition, CUR significantly reduced hepatic ROS, malondialdehyde, hydrogen peroxide and apoptosis levels in mice (p < 0.05). Quantitative RT-PCR and Western blot results showed that CUR significantly reduced the expression of Bax and Caspase3, and reversed the increase of Nrf2, HO-1 and NQO1 expression in the liver of mice induced by ZEN (p < 0.05). In conclusion, CUR alleviated ZEN-induced liver injury in mice by scavenging ROS and inhibiting the mitochondrial apoptotic pathway.

Identification of the hub genes linked to zearalenone-induced hepatotoxicity in broiler chickens

Zearalenone (ZEN) is a mycotoxin found in food and feed that impairs the function of multiple organs, especially the liver. However, the specific mechanisms through which ZEN induces liver damage in broiler chickens are not well understood. Therefore, this study aimed to identify the key genes linked to the hepatotoxicity induced by ZEN exposure in broiler chickens. Gene expression data from ZEN-treated and control chicken embryo primary hepatocytes (CEPHs) were used to implement differential expression analysis. Totally, 436 differentially expressed genes (DEGs) were detected, in which 223 and 213 genes were up- and down-regulated in ZEN-treated CEPHs, respectively. Gene ontology analysis suggested that these DEGs were involved in various biological processes, including chromosome segregation, mitotic cytokinesis, mitotic cell cycle, cell division, and mitotic spindle organization. Pathway analysis showed that the DEGs were associated with p53, FoxO, ubiquitin-mediated proteolysis, cell cycle, and mismatch repair signaling pathways. Furthermore, the hub genes, including BRCA1, CDC45, CDCA3, CDKN3, CENPE, CENPF, CENPI, CENPM, CENPU, and CEP55, potentially contributed to ZEN-induced hepatotoxicity. In conclusion, our study provides the valuable insight into the mechanism underlying ZEN-induced hepatotoxicity in broiler chickens.

Integrated spatial metabolomics and transcriptomics decipher the hepatoprotection mechanisms of wedelolactone and demethylwedelolactone on non-alcoholic fatty liver disease

Eclipta prostrata L. has been used in traditional medicine and known for its liver-protective properties for centuries. Wedelolactone (WEL) and demethylwedelolactone (DWEL) are the major coumarins found in E. prostrata L. However, the comprehensive characterization of these two compounds on non-alcoholic fatty liver disease (NAFLD) still remains to be explored. Utilizing a well-established zebrafish model of thioacetamide (TAA)-induced liver injury, the present study sought to investigate the impacts and mechanisms of WEL and DWEL on NAFLD through integrative spatial metabolomics with liver-specific transcriptomics analysis. Our results showed that WEL and DWEL significantly improved liver function and reduced the accumulation of fat in the liver. The biodistributions and metabolism of these two compounds in whole-body zebrafish were successfully mapped, and the discriminatory endogenous metabolites reversely regulated by WEL and DWEL treatments were also characterized. Based on spatial metabolomics and transcriptomics, we identified that steroid biosynthesis and fatty acid metabolism are mainly involved in the hepatoprotective effects of WEL instead of DWEL. Our study unveils the distinct mechanism of WEL and DWEL in ameliorating NAFLD, and presents a "multi-omics" platform of spatial metabolomics and liver-specific transcriptomics to develop highly effective compounds for further improved therapy.

Oxidative Status and Histological Evaluation of Wild Boars' Tissues Positive for Zearalenone Contamination in the Campania Region, Southern Italy

Zearalenone (ZEN) is a mycotoxin produced by fungi belonging to the genera Fusarium spp. and commonly found in feed and food. It is frequently related to reproductive disorders in farm animals and, occasionally, to hyperestrogenic syndromes in humans. Nowadays, knowledge about ZEN effects on wild boars (Sus scrofa) is extremely scarce, despite the fact that they represent one of the most hunted game species in Italy. The aim of this study was to investigate how ZEN affects the liver, kidney, and muscle oxidative status and morphology of wild boars hunted in various locations throughout the province of Avellino, Campania Region, Southern Italy, during the 2021-2022 hunting season. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, as well as the malondialdehyde (MDA) levels, were assessed by colorimetric assays; tissue morphology was evaluated by hematoxylin-eosin and Masson's stains. Our data showed that ZEN contamination might result in oxidative stress (OS) and some histopathological alterations in wild boars' livers and kidneys rather than in muscles, emphasizing the importance of developing a wildlife monitoring and management strategy for dealing not only with the problem of ZEN but the surveillance of mycotoxins in general.

High-Resolution Magic Angle Spinning (HRMAS) NMR Identifies Oxidative Stress and Impairment of Energy Metabolism by Zearalenone in Embryonic Stages of Zebrafish (Danio rerio), Olive Flounder (Paralichthys olivaceus) and Yellowtail Snapper (Ocyurus chrysurus)

Zearalenone (ZEA) is a mycotoxin, commonly found in agricultural products, linked to adverse health impacts in humans and livestock. However, less is known regarding effects on fish as both ecological receptors and economically relevant "receptors" through contamination of aquaculture feeds. In the present study, a metabolomics approach utilizing high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) was applied to intact embryos of zebrafish (Danio rerio), and two marine fish species, olive flounder (Paralichthys olivaceus) and yellowtail snapper (Ocyurus chrysurus), to investigate the biochemical pathways altered by ZEA exposure. Following the assessment of embryotoxicity, metabolic profiling of embryos exposed to sub-lethal concentrations showed significant overlap between the three species and, specifically, identified metabolites linked to hepatocytes, oxidative stress, membrane disruption, mitochondrial dysfunction, and impaired energy metabolism. These findings were further supported by analyses of tissue-specific production of reactive oxygen species (ROS) and lipidomics profiling and enabled an integrated model of ZEA toxicity in the early life stages of marine and freshwater fish species. The metabolic pathways and targets identified may, furthermore, serve as potential biomarkers for monitoring ZEA exposure and effects in fish in relation to ecotoxicology and aquaculture.

Novel insights into versatile nanomaterials integrated bioreceptors toward zearalenone ultrasensitive discrimination

Detrimental contamination of zearalenone (ZEN) in crops and foodstuffs has drawn intensive public attention since it poses an ongoing threat to global food security and human health. Highly sensitive and rapid response ZEN trace analysis suitable for complex matrices at different processing stages is an indispensable part of food production. Conventional detection methods for ZEN encounter many deficiencies and demerits such as sophisticated equipment and heavy labor intensity. Alternatively, the nanomaterial-based biosensors featured with high sensitivity, portability, and miniaturization are springing up and emerging as superb substitutes to monitor ZEN in recent years. Herein, we predominantly devoted to overview the progress in the fabrication strategies and applications of various nanomaterial-based biosensors, highlighting rationales on sensing mechanisms, response types, and practical analytical performance. Synchronously, the versatile nanomaterials integrating with diverse recognition elements for augmenting sensing capabilities are emphasized. Finally, critical challenges and perspectives to expedite ZEN detection are outlooked.