Aflatoxin B1 induces liver injury by disturbing gut microbiota-bile acid-FXR axis in mice

Sub-chronic realgar exposure causes liver inflammatory injury in mice by inducing bile acid-mediated NLRP3 inflammasome activation through down-regulation of ileal FXR

ETHNOPHARMACOLOGICAL RELEVANCE

Realgar is extensively utilized in both modern medicine and traditional Chinese medicine. Although it has therapeutic uses, realgar exhibits hepatotoxicity, and improper use can result in liver inflammation and injury. The disruption of bile acid (BA) homeostasis, identified as an initiating event in liver injury, has been observed in the livers of realgar-exposed mice. However, the relationship between realgar-induced BA homeostasis imbalance and liver inflammation remains to be elucidated.

AIM OF THE STUDY

To investigate the relationship between hepatic BA homeostasis disorder and liver inflammation caused by realgar exposure in mice, as well as the role and potential mechanism of intestinal farnesoid X receptor (FXR) in realgar-induced liver inflammation.

METHODS

A sub-chronic realgar exposure mouse model was established and subjected to interventions with an intestinal-restricted FXR agonist or inhibitor. Plasma hepatic enzyme activities and total bile acid (TBA) levels were quantified using spectrophotometry. Hepatic inflammatory cytokine levels were analyzed by ELISA or RT-qPCR. Histopathological evaluation of liver injury was performed using HE staining. F4/80 expression was assessed via immunohistochemistry (IHC). Western blot (WB) and IHC were employed to examine the expression of proteins involved in the FXR-FGF15 axis, and plasma FGF15 concentrations were determined by ELISA. The expression of proteins related to enterohepatic circulation and the NLRP3 inflammasome pathway were evaluated using WB. Ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS) was utilized to analyze BA profiles in both ileal and hepatic tissues.

RESULTS

Our findings demonstrate that realgar exposure induces changes in ileal BA composition and subsequent suppression of the FXR-FGF15 signaling axis in mice. This axis suppression promotes hepatic BA overproduction and disrupts BA homeostasis in the livers of realgar-exposed mice, particularly elevates the levels of taurochenodeoxycholic acid (TCDCA) and taurolithocholic acid (TLCA). In vitro studies revealed that both TCDCA and TLCA can directly activate the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in AML-12 cells, triggering pro-inflammatory cascades. Pharmacological activation of intestinal FXR effectively ameliorated realgar-induced hepatic inflammatory damage via restoring BA homeostasis and suppressing NLRP3 inflammasome activation.

CONCLUSION

Realgar exposure causes liver inflammatory injury by inducing BA-mediated NLRP3 inflammasome activation through down-regulating ileal FXR. Pharmacological activation of intestinal FXR alleviates realgar-induced liver inflammatory injury by restoring BA homeostasis and inhibiting BA-mediated NLRP3 inflammasome activation. These findings suggest that intestinal FXR may serve as a potential target for the prevention and treatment of realgar-induced liver injury.

Mechanistic insights into deoxynivalenol-Induced hepatic cholestasis via IRE1α/HNF1α/FXR signaling dysregulation in mice

Deoxynivalenol (DON), a trichothecene mycotoxin ubiquitously contaminating agricultural commodities, foodstuffs, and water systems, poses significant health risks to humans and livestock. As the primary detoxification organ, the liver exhibits marked susceptibility to DON-induced toxicity. Our study demonstrated that DON triggers hepatocellular injury by disrupting bile acid (BA) homeostasis and activating pro-inflammatory cascades. In murine models, DON exposure significantly elevated systemic and intrahepatic total bile acid (TBA) levels while upregulating pro-inflammatory cytokine expression. Notably, the accumulation of conjugated BAs and transcriptional dysregulation of BA-metabolizing genes identified farnesoid X receptor (FXR) suppression as the central mechanism driving DON-mediated cholestasis. Mechanistically, DON activates the Inositol-Requiring Enzyme 1α (IRE1α) branch of the unfolded protein response, leading to hepatic nuclear factor 1α (HNF1α) suppression via RNase-dependent mRNA degradation. This HNF1α downregulation directly attenuates FXR transcription, defining a novel IRE1α-HNF1α-FXR signaling axis in cholestatic pathogenesis. Pharmacological targeting of FXR with GW4064 or inhibition of IRE1α with KIRA6 effectively ameliorated DON-induced cholestasis and hepatocellular damage, validating this axis as a therapeutic target. These findings delineate the molecular crosstalk between endoplasmic reticulum stress and nuclear receptor signaling in mycotoxin hepatotoxicity and establish a mechanistic framework for mitigating DON contamination risks. By elucidating IRE1α's regulatory role and FXR's function in BA homeostasis, this study provides a foundation for developing interventions against foodborne toxicant-induced liver pathologies.

Microbial Metabolite Effects on Vasculogenic Mimicry in Metastatic Cancers

Aggressive cancer cells can form new, functional blood vessel-like structures independently of endothelial cells, known as vasculogenic mimicry (VM), instead of the usual tumor blood vessel formation process. However, the symbiotic relationship between microbial communities and human cells ensures the upkeep of cellular metabolism and the functionality of the immune system and metastatic cancers. This interaction typically happens through the generation and management of hormonal intermediates, metabolites, secondary metabolites, proteins, and toxins. A disturbance in the balance between the host and microbiota can alter the dynamics of their relationship, creating a conducive environment for the development of diseases, such as cancers. This review aims to synthesize the initial evidence on the molecular processes governing the interactions between GM and cancer development and emphasize microbial metabolites' effects on vasculogenic mimicry. Some microbial metabolites could also contribute to developing interactions between microbes and the tumor microenvironment. While numerous obstacles persist, GM's immense significance and complete capability in shaping tailored anticancer plans cannot be exaggerated, highlighting the need to investigate a holistic method that includes microbial modulation therapy in cancer management.

Dietary Supplementation of Novel Aflatoxin Oxidase CotA Alleviates Aflatoxin B1-Induced Oxidative Stress, Lipid Metabolism Disorder, and Apoptosis in the Liver of Japanese Quails

This research explored the role of aflatoxin oxidase CotA in mitigating aflatoxin B1 (AFB1)-induced hepatotoxicity in Japanese quails. A total of 225 female Japanese quails, aged two weeks, were randomly assigned to three dietary groups: a control diet, an AFB1-contaminated diet, and an AFB1-contaminated diet supplemented with aflatoxin oxidase CotA for three weeks. The results indicate that quails receiving the AFB1-contaminated diet exhibited reduced body weight gain, pronounced vacuolar degeneration within hepatocytes, and inflammatory cell infiltration. Additionally, the AFB1 group demonstrated an increased liver index and elevated serum liver enzyme activities (ALT, AST, and ALP). Supplementation with CotA improved body weight gain and conferred protection against AFB1-induced liver injury. Furthermore, the addition of CotA significantly enhanced liver antioxidant enzyme activities (T-AOC, GST, GSH-Px, POD, and CAT), reduced hepatic H2O2 and MDA levels, and upregulated the mRNA expression levels of genes in the Nrf2 pathway in quails exposed to AFB1. AFB1 exposure led to lipid droplet accumulation in liver tissues and elevated serum TG and LDL-C levels. However, the introduction of CotA mitigated AFB1-induced alterations in lipid metabolism. Furthermore, dietary supplementation with CotA inhibited AFB1-induced hepatocyte apoptosis and decreased the mRNA expression of apoptosis-related genes, including Bax, caspase-9, and caspase-3. Notably, the AFB1+CotA group exhibited a significant reduction in AFB1 residues and AFB1-DNA adducts in quail liver tissues compared to the AFB1 group. These findings indicate that aflatoxin oxidase CotA holds promise as a feed additive to alleviate AFB1-induced hepatotoxicity.

Hepatoprotective effects of dandelion against AFB1-induced liver injury are associated with activation of bile acid-FXR signaling in chicks

This study aimed to investigate the protective effects of dandelion against AFB1-induced hepatotoxicity through the regulation of the FXR signaling pathway in chicks. A total of 144 one-day-old male broilers were randomly assigned to three groups and received a basal diet (BD), and BD supplemented with 0.5 mg/kg of AFB1 or 0.5 mg/kg AFB1 with 0.4 % dandelion for 3 weeks. The results showed that the AFB1 treatment caused liver injury and decreased the concentrations of albumin and alkaline phosphatase in serum and increased the total bile acid concentration in serum and liver. Dietary AFB1 supplementation also induced hepatocyte swelling, necrosis, neutrophils infiltration and lipid deposition in the liver. Notably, dietary dandelion supplementation alleviated these alterations induced by AFB1. Additionally, dietary dandelion supplementation alleviated AFB1-induced changes in ileum microbiota and decreased the abundance of Lactobacillus, L. vaginalis, and L. acidophilus compared to the AFB1 treatment. Furthermore, AFB1 downregulated Baat, Ntcp, Acc, FXR, SHP, and SREBP-1c expression, and upregulated Cyp8b1, Bacs, Fas, Pparα, Lxrα and CYP7A1 expression in liver. Meanwhile, AFB1 also downregulated Fgf19, Ostα, Ostβ and FXR expression and upregulated SHP expression in the ileum. Conclusively, dietary dandelion supplementation protected broilers from AFB1-induced hepatotoxicity, potentially due to the activation of bile acid-FXR signaling pathway.

Fecal metabonomics combined with 16S rRNA gene sequencing to study the mechanisms of cantharidin-induced hepatotoxicity

Cantharidin (CTD) serves as the principal bioactive compound in traditional Chinese medicine Mylabris, commonly employed in cancer treatment. Nevertheless, the clinical application of CTD is partly restricted by hepatotoxicity, and the toxicology mechanism is not fully elucidated. This study aims to explore the potential mechanism of CTD-induced hepatoxicity by targeted metabolomics-based UPLC-QTOF-MS/MS analysis and 16S rRNA sequencing. Studies have shown that the administration of CTD could lead to elevated serum biochemical indices including ALT and AST. Notably, dilatation of the liver central vein, hepatocellular necrosis, and slight vacuoles in rats were observed after CTD intervention. Fecal metabolomics found CTD could up-regulate 10 and down-regulate 33 metabolites, and metabolic pathway enrichment found that CTD could disrupt 2 metabolic pathways, including Arginine biosynthesis metabolism and β-Alanine metabolism. 16S rRNA gene sequencing analysis showed that CTD could increase the abundance of Turicibacter and Clostridium sensu stricto 1, but decrease the amounts of Prevotella 1. Our correlation analyses showed that alterations in the gut microbiota induced by CTD in rats may have impacted changes in the associated hepatic amino acid metabolism pathway. And the mechanism of action of CTD-induced hepatotoxicity may be related to inflammation, oxidative stress, impaired glucose metabolism and reduced hepatic glycogen storage. These findings will offer novel insights for the prevention and treatment of CTD-induced hepatotoxicity.

Unveiling the Dark Side of Flavonoid: Rutin Provokes Hepatotoxicity in Low-Dose 2-Amino-3-methylimidazo [4,5-f] Quinoline-Exposed Mice via Regulating Gut Microbiota and Liver Metabolism

2-Amino-3-methylimidazole [4,5-f] quinoline (IQ) is a kind of heterocyclic amine (HCAs) with high carcinogenicity in hot processed meat. Rutin (Ru) is a flavonoid compound with anti-inflammatory and antioxidant properties. However, whether Ru is scatheless under IQ-stimulated potential unhealthy conditions, especially liver function, in vivo, is unknown. In this study, we explored the effects and underlying mechanism of Ru on liver injury induced by a low dose of IQ in mice. Results showed that Ru supplement led to liver injury upon low-dose IQ alone administration, as shown by histological analysis, inflammatory, and serum biochemical indexes. Additionally, nontargeted metabolomics analysis revealed that coexposure of Ru and IQ disrupted liver metabolic balance, leading to significant changes in metabolites and metabolic pathways, hinting at a possible relationship with intestinal microbiota. Furthermore, the 16S rRNA sequencing data indicated that a combination of Ru and IQ caused gut microbiota dysbiosis and decreased the level of short-chain fatty acids (SCFAs). Correlation analysis between gut microbiota, SCFAs, liver metabolites, and liver damage markers highlighted the crucial role of the gut-liver axis in IQ and Ru coexposure-induced liver injury in vivo. In general, this study offers a valuable perspective on flavones and HCA compounds in the realms of food safety and human health.

Selenomethionine Attenuates Aflatoxin B1-induced Liver Injury by Modulating the Gut Microbiota and Metabolites in Rabbits

Dietary contamination with aflatoxin B1 (AFB1), which can lead to severe liver damage, poses a great threat to livestock and poultry breeding and has detrimental impacts on food safety. Selenomethionine (SeMet), with anti-inflammatory, antioxidative, and detoxifying effects, is regarded as a beneficial food additive. However, whether SeMet can reduce AFB1-induced liver injury and intestinal microbial disorders in rabbits remains to be revealed. Forty 35-day-old rabbits were randomly divided into a control group, an AFB1 group, and 0.2 mg/kg Se and 0.4 mg/kg Se groups. The SeMet treatment group was fed different doses of the SeMet diet every day for 21 days. On Days 17-21, the AFB1 group, 0.2 mg/kg Se, and 0.4 mg/kg Se groups were intragastrically administered 0.3 mg AFB1/kg b.w. Results showed that SeMet restored alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, alleviating AFB1-induced liver function damage. This was linked to changes in intestinal metabolites and activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway. In this study, the relationships between intestinal microorganisms and their metabolites and AFB1-induced liver injury are investigated, and the potential protective role of SeMet against liver damage induced by AFB1 offers novel insights into strategies for the prevention and treatment of AFB1-related toxicity.

Ameliorative Effect of Glycyrrhizic Acid on Diosbulbin B-Induced Liver Injury and Its Mechanism

This study aimed to clarify the protective effect of Glycyrrhizic acid (GL) against Diosbulbin B (DB) - induced liver injury in mice and investigate its mechanisms of action. A liver injury DB was established in mice through the oral administration of DB for 15 days. At the same time, GL was administered to the mice for treatment. After the experiment, the pharmacodynamics and mechanisms of GL in ameliorating DB-induced liver injury were explored using biochemical indexes, non-targeted metabolomics, targeted metabolomics, Western blotting analysis of protein expression, 16S rDNA sequencing, and Spearman correlation analysis. The results show reduced liver function indices and improved DB-induced hepatic pathological changes. It also attenuated DB-induced hepatic inflammation and oxidative stress. Hepatic metabolomics revealed that GL regulated ABC transporters and bile secretion. Targeted bile acid (BA) metabolomics and Western blotting demonstrated that GL improved DB-induced reduction in BA efflux by regulating FXR-mediated efflux transporters. Furthermore, analysis of 16S rDNA gene sequencing revealed that GL effectively restored the relative abundance of beneficial bacteria, reduced the relative abundance of harmful bacteria, and reinstated the structure of the intestinal flora. Additionally, correlation analyses between BA and intestinal flora indicated that Firmicutes, Bacteroidota, TDGA, DGA, UDGA, GDGA, THDGA, and HDGA could serve as major markers for DB-induced liver injury. In conclusion, GL significantly improved DB-induced liver injury by increasing the expression of Nrf2/FXR-BSEP/MRP2/P-gp/UGT1A1, promoting BA efflux, regulating intestinal flora, and alleviating inflammation and oxidative stress.

Aflatoxin B1-induced hepatotoxicity through mitochondrial dysfunction, oxidative stress, and inflammation as central pathological mechanisms: A review of experimental evidence

Aflatoxin B1 (AFB1) is a class of mycotoxin known to contaminate agricultural products, animal feed and animal food products, subsequently causing detrimental effects on human and animal health. AFB1 is the most common and potent aflatoxin found in food and contributes significantly to liver injury as well as the development of hepatocellular carcinoma. Although the liver is a primary target organ for AFB1 toxicity and biotransformation, underlying mechanisms implicated in liver injuries induced by these mycotoxins remain to be fully elucidated for therapeutic purposes. This review aims to dissect the complexities of the pathophysiological and molecular mechanisms implicated in hepatotoxicity induced by AFB1, including mitochondrial dysfunction, oxidative stress and hepatic inflammation. Mechanistically, AFB1 disrupt mitochondrial bioenergetics and membrane potential, promotes mitochondrial cholesterol trafficking and induces mitophagy. Moreover, mitochondrial dysfunction may lead to hepatic oxidative stress as a consequence of uncontrolled production of reactive oxygen species and defects in the antioxidant defense system. Retrieved experimental evidence also showed that AFB1 may lead to hepatic inflammation through gut microbiota dysbiosis, the release of DAMPs and cytokines, and immune cell recruitment. Overall, these mechanisms could be utilized as potential targets to extrapolate treatment for liver injury caused by AFB1.

Probiotic-derived extracellular vesicles alleviate AFB1-induced intestinal injury by modulating the gut microbiota and AHR activation

BACKGROUND

Aflatoxin B1 (AFB1) is a mycotoxin that widely found in the environment and mouldy foods. AFB1 initially targets the intestine, and AFB1-induced intestinal injury cannot be ignored. Lactobacillus amylovorus (LA), a predominant species of Lactobacillus, plays a role in carbohydrate metabolism. Extracellular vesicles (EVs), small lipid membrane vesicles, are widely involved in diverse cellular processes. However, the mechanism by which Lactobacillus amylovorus-QC1H-derived EVs (LA.EVs) protect against AFB1-induced intestinal injury remains unclear.

RESULTS

In our study, a new strain named Lactobacillus amylovorus-QC1H (LA-QC1H) was isolated from pig faeces. Then, EVs derived from LA-QC1H were extracted via ultracentrifugation. Our results showed that LA.EVs significantly alleviated AFB1-induced intestinal injury by inhibiting the production of proinflammatory cytokines, decreasing intestinal permeability and increasing the expression of tight junction proteins. Moreover, 16 S rRNA analysis revealed that LA.EVs modulated AFB1-induced gut dysbiosis in mice. However, LA.EVs did not exert beneficial effects in antibiotic-treated mice. LA.EVs treatment increased intestinal levels of indole-3-acetic acid (IAA) and activated intestinal aryl hydrocarbon receptor (AHR)/interleukin-22 (IL-22) signalling in AFB1-exposed mice. Inhibition of intestinal AHR signalling markedly weakened the protective effect of LA.EVs in AFB1-exposed mice.

CONCLUSIONS

LA.EVs alleviated AFB1-induced intestinal injury by modulating the gut microbiota, activating the intestinal AHR/IL-22 signalling, reducing the inflammatory response and promoting intestinal barrier repair in mice.

Discovery of Tetrahydro Tanshinone I as a Naturally Occurring Covalent Pan-Inhibitor Against Gut Microbial Bile Salt Hydrolases

Gut microbial bile salt hydrolases (gmBSHs), an important class of bacteria-produced cysteine hydrolases, play a crucial role in bile acid metabolism. Modulating the total gmBSH activity is a feasible way for ameliorating some metabolic diseases including colorectal cancer, type 2 diabetes, and obesity. This study reported the discovery and characterization of a botanical compound as a covalent pan-inhibitor of gmBSHs. Following the screening of more than 100 botanical compounds, tanshinones were found with strong time-dependent anti-EfBSH effects. After that, a total of 17 naturally occurring tanshinones were collected, and their anti-EfBSH potentials were tested. Among all tested tanshinones, tetrahydro tanshinone I (THTI) exhibited the most potent inhibitory effects against five gmBSHs (EfBSH, LsBSH, BtBSH, CpBSH, and BlBSH), showing the IC50 values ranging from 0.28 ± 0.05 μM to 1.62 ± 0.07 μM. Further investigations showed that THTI could covalently modify the conserved catalytic cysteine (Cys2) of all tested gmBSHs, while this agent could strongly inhibit the total gmBSHs activity in live microorganisms and murine gut luminal content. Collectively, THTI is identified as a naturally occurring covalent pan-inhibitor of gmBSHs, which offers a promising lead compound to develop more efficacious gmBSHs inhibitors for the management of bile acid metabolism and related metabolic disorders.

Biological Mechanisms of Aflatoxin B1-Induced Bile Metabolism Abnormalities in Ducklings

This study investigated the effects and biological mechanisms of aflatoxin B1 (AFB1) on the health and bile metabolism of ducklings. Forty-eight 1-day-old ducklings were randomly assigned to two groups, with six replicates per group. The control group was fed a basic diet, while the AFB1 group received a diet containing 90 µg/kg of AFB1. The experiment lasted for 2 weeks. The results showed that 90 µg/kg AFB1 caused abnormal bile metabolism; damaged liver cell nuclei and mitochondria; and significantly decreased body weight, average daily weight gain, and levels of albumin, total protein, cholesterol, total superoxide dismutase, glutathione peroxidase, and glutathione. It also significantly increased feed conversion efficiency, along with alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bile acids, and malondialdehyde levels. In the liver, the expression levels of CYP7A1, SCD, and other genes were significantly upregulated, while BSEP, FASN, HMGCR, CAT, and other genes were significantly downregulated. In conclusion, AFB1 causes abnormal bile metabolism and impairs the overall health and liver function of ducklings. Its mechanism of action may involve changes in gene expression related to bile acid metabolism, lipid metabolism, oxidative damage, and cancer pathways.

mtROS-mediated mitophagy is involved in aflatoxin-B1 induced liver injury in ducks

Aflatoxin B1 (AFB1) is highly toxic to the liver and can cause excessive production of mitochondrial reactive oxygen species (mtROS) in hepatocytes, leading to oxidative stress, inflammation, fibrosis, cirrhosis, and even liver cancer. The overproduction of mtROS can induce mitophagy, but whether mtROS and mitophagy are involved in the liver injury induced by AFB1 in ducks remains unclear. In this study, we first demonstrated that overproduction of mtROS and mitophagy occurred during liver injury induced by AFB1 exposure in ducks. Then, by inhibiting mtROS and mitophagy, we found that the damage caused by AFB1 in ducks was significantly alleviated, and the overproduction of mtROS induced by AFB1 exposure could mediate the occurrence of mitophagy. These results suggested that mtROS-mediated mitophagy is involved in AFB1-induced duck liver injury, and they may be the prevention and treatment targets of AFB1 hepatotoxicity.

A facile dual-mode SERS/fluorescence aptasensor for AFB1 detection based on gold nanoparticles and magnetic nanoparticles

Aflatoxin B1 (AFB1) is a virulent metabolite secreted by Aspergillus fungi, impacting crop quality and posing health risks to human. Herein, a dual-mode Raman/fluorescence aptasensor was constructed to detect AFB1. The aptasensor was assembled by gold nanoparticles (AuNPs) and magnetic nanoparticles (MNPs), while the surface-enhanced Raman scattering (SERS) and fluorescence resonance energy transfer (FRET) effects were both realized. AuNPs were modified with the Raman signal molecule 4-MBA and the complementary chain of AFB1 aptamer (cDNA). MNPs were modified with the fluorescence signal molecule Cy5 and the AFB1 aptamer (AFB1 apt). Through base pairing, AuNPs aggregated on the surface of MNPs, forming a satellite-like nanocomposite, boosting SERS signal via increased "hot spots" but reducing fluorescence signal due to the proximity of AuNPs to Cy5. Upon exposure to AFB1, AFB1 apt specifically bound to AFB1, causing AuNPs detachment from MNPs, weakening the SERS signal while restoring the fluorescence signal. AFB1 concentration displayed a good linear relationship with SERS/fluorescence signal in the range of 0.01 ng/mL-100 ng/mL, with a detection limit as low as 5.81 pg/mL. The use of aptamer assured the high selectivity toward AFB1. Furthermore, the spiked recovery in peanut samples ranged from 91.4 % to 95.6 %, indicating the applicability of real sample detection. Compared to single-signal sensor, this dual-signal sensor exhibited enhanced accuracy, robust anti-interference capability, and increased flexibility, promising for toxin detection in food safety applications.

The Effects of Aflatoxin B1 on Liver Cholestasis and Its Nutritional Regulation in Ducks

The aim of this study was to investigate the effects of aflatoxin B1 (AFB1) on cholestasis in duck liver and its nutritional regulation. Three hundred sixty 1-day-old ducks were randomly divided into six groups and fed for 4 weeks. The control group was fed a basic diet, while the experimental group diet contained 90 μg/kg of AFB1. Cholestyramine, atorvastatin calcium, taurine, and emodin were added to the diets of four experimental groups. The results show that in the AFB1 group, the growth properties, total bile acid (TBA) serum levels and total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and glutathione (GSH) liver levels decreased, while the malondialdehyde (MDA) and TBA liver levels increased (p < 0.05). Moreover, AFB1 caused cholestasis. Cholestyramine, atorvastatin calcium, taurine, and emodin could reduce the TBA serum and liver levels (p < 0.05), alleviating the symptoms of cholestasis. The qPCR results show that AFB1 upregulated cytochrome P450 family 7 subfamily A member 1 (CYP7A1) and cytochrome P450 family 8 subfamily B member 1 (CYP8B1) gene expression and downregulated ATP binding cassette subfamily B member 11 (BSEP) gene expression in the liver, and taurine and emodin downregulated CYP7A1 and CYP8B1 gene expression (p < 0.05). In summary, AFB1 negatively affects health and alters the expression of genes related to liver bile acid metabolism, leading to cholestasis. Cholestyramine, atorvastatin calcium, taurine, and emodin can alleviate AFB1-induced cholestasis.

Salvia miltiorrhiza polysaccharide mitigates AFB1-induced liver injury in rabbits

Aflatoxin B1 (AFB1) is one of the common dietary contaminants worldwide, which can harm the liver of humans and animals. Salvia miltiorrhiza polysaccharide (SMP) is a natural plant-derived polysaccharide with numerous pharmacological activities, including hepatoprotective properties. The purpose of this study is to explore the intervention effect of SMP on AFB1-induced liver injury and its underlying mechanisms in rabbits. The rabbits were administered AFB1 (25 μg/kg/feed) and or treatment with SMP (300, 600, 900 mg/kg/feed) for 42 days. The results showed that SMP effectively alleviated the negative impact of AFB1 on rabbits' productivity by increasing average daily weight gain (ADG) and feed conversion rate (FCR). SMP reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels in serum, ameliorating AFB1-induced hepatic pathological changes. Additionally, SMP enhanced superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) activity, and inhibited reactive oxygen species (ROS), malondialdehyde (MDA), 4-Hydroxynonenal (4-HNE), interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression, thus mitigating AFB1-induced oxidative stress and inflammatory responses. Moreover, SMP upregulated the expression of nuclear factor E2 related factor 2 (Nrf2), heme oxygenase 1 (HO-1), NADPH quinone oxidoreductase 1 (NQO1) and B-cell lymphoma 2 (Bcl2) while downregulating kelch like ECH associated protein 1 (Keap1), cytochrome c (cyt.c), caspase9, caspase3, and Bcl-2-associated X protein (Bax) expression, thereby inhibiting AFB1-induced hepatocyte apoptosis. Consequently, our findings conclude that SMP can mitigate AFB1-induced liver damage by activating the Nrf2/HO-1 pathway and inhibiting mitochondria-dependent apoptotic pathway in rabbits.

Aflatoxin B1 exposure causes splenic pyroptosis by disturbing the gut microbiota-immune axis

Aflatoxin B1 (AFB1) causes serious immunotoxicity and has attracted considerable attention owing to its high sensitivity and common chemical-viral interactions in living organisms. However, the sensitivity of different species to AFB1 widely varies, which cannot be explained by the different metabolism in species. The gut microbiota plays a crucial role in the immune system, but the interaction of the microbiota with AFB1-induced immunotoxicity still needs to be determined. Our results indicated that AFB1 exposure disrupted the structure of the gut microbiota and damaged the gut barrier, which caused translocation of microbiota metabolites, lipopolysaccharides, to the spleen. Subsequently, pyroptosis of the spleen was activated. Interestingly, AFB1 exposure had little effect on the splenic pyroptosis of pseudo-germfree mice (antibiotic mixtures eliminated their gut microbiota, ABX). Then, fecal microbiota transplant (FMT) and sterile fecal filtrate (SFF) were employed to validate the function of the gut microbiota and its metabolites in AFB1-induced splenic pyroptosis. The AFB1-disrupted microbiota and its metabolites significantly promoted splenic pyroptosis, which was worse than that in control mice. Overall, AFB1-induced splenic pyroptosis is associated with the gut microbiota and its metabolites, which was further demonstrated by FMT and SFF. The mechanism of AFB1-induced splenic pyroptosis was explored for the first time, which paves a new way for preventing and treating the immunotoxicity from mycotoxins by regulating the gut microbiota.

Multi-omics reveals the protective effects of curcumin against AFB1-induced oxidative stress and inflammatory damage in duckling intestines

Aflatoxin B1 (AFB1) is the most prevalent and toxic class of aflatoxins, which is considered a significant risk factor for food safety. Curcumin, a phytoconstituent with anti-inflammatory and antioxidant properties, has potential therapeutic value for intestinal inflammatory diseases. In this study, the duckling model susceptible to AFB1 was selected for toxicity testing, aiming to explore the effect of curcumin on AFB1 enterotoxicity and its possible mechanism of action. The results showed that curcumin promoted the growth and development of ducklings and mitigated the changes in morphology and permeability serological index (DAO and D-LA) after AFB1 exposure. Curcumin also mitigated AFB1-induced oxidative stress by activating the Nrf2 pathway, and ameliorated intestinal inflammation by inhibiting the NF-κB/IκB signaling pathway and boosting intestinal autophagy. In terms of gut flora and their metabolites, we found that curcumin supplementation significantly increased the intestinal flora's abundance index and diversity index compared to the AFB1 group, mitigating the decline in the abundance of Actinobacteria and the rise in that of harmful bacteria Clostridia. Furthermore, untargeted metabolomic analysis revealed that the protective effect of curcumin on the intestine was mainly through the regulation of AFB1-induced disorders of lipid metabolism, involving linoleic acid metabolism, α-linolenic acid metabolism, and glycerolipid metabolism. Overall, the enteroprotective effects of curcumin may be of significant value in the future for treating chronic AFB1 poisoning and also provide new therapeutic ideas for other mycotoxicosis.

Mefentrifluconazole exposure disrupted hepatic lipid metabolism disorder tightly associated with gut barrier function abnormal in mice

Mefentrifluconazole (MFZ) is an azole fungicide that is placed in agriculture for the control of fungal hazards. However, due to their non-biodegradability, azole fungicides can accumulate in plants, animals, and the environment, thus becoming a major health concern worldwide. In this study, we exposed 7-week-old C57BL/6 mice to 10, 30, and 100 mg/kg of MFZ for 28 d to assess the toxic effects of MFZ on the liver and gut tissues of the mice. Histopathological, biochemical indexes, and transcriptomic analyses revealed that MFZ exposure disrupted the liver structure and hepatic lipid metabolism as well as damaged gut barrier function and promoted inflammation in mice. Moreover, 16S rRNA sequencing demonstrated that MFZ exposure significantly increased the abundance of patescibacteria at the generic level. Also, MFZ exposure increased the abundance of bacterial genera associated with inhibition of glycolipid metabolism. These results suggested that the disruption of liver lipid metabolism caused by MFZ exposure may be caused by changes in gut microbiota function. This study provided a new disease occurrence study for risk assessment of MFZ and strengthened the focus on some novel fungicides.

Excess iron intake induced liver injury: The role of gut-liver axis and therapeutic potential

Excessive iron intake is detrimental to human health, especially to the liver, which is the main organ for iron storage. Excessive iron intake can lead to liver injury. The gut-liver axis (GLA) refers to the bidirectional relationship between the gut and its microbiota and the liver, which is a combination of signals generated by dietary, genetic and environmental factors. Excessive iron intake disrupts the GLA at multiple interconnected levels, including the gut microbiota, gut barrier function, and the liver's innate immune system. Excessive iron intake induces gut microbiota dysbiosis, destroys gut barriers, promotes liver exposure to gut microbiota and its derived metabolites, and increases the pro-inflammatory environment of the liver. There is increasing evidence that excess iron intake alters the levels of gut microbiota-derived metabolites such as secondary bile acids (BAs), short-chain fatty acids, indoles, and trimethylamine N-oxide, which play an important role in maintaining homeostasis of the GLA. In addition to iron chelators, antioxidants, and anti-inflammatory agents currently used in iron overload therapy, gut barrier intervention may be a potential target for iron overload therapy. In this paper, we review the relationship between excess iron intake and chronic liver diseases, the regulation of iron homeostasis by the GLA, and focus on the effects of excess iron intake on the GLA. It has been suggested that probiotics, fecal microbiota transfer, farnesoid X receptor agonists, and microRNA may be potential therapeutic targets for iron overload-induced liver injury by protecting gut barrier function.

Study on Dihydromyricetin Improving Aflatoxin Induced Liver Injury Based on Network Pharmacology and Molecular Docking

Aflatoxin B1 (AFB1) is a toxic food/feed contaminant and the liver is its main target organ, thus it poses a great danger to organisms. Dihydromyricetin (DHM), a natural flavonoid compound, can be used as a food additive with high safety and has been shown to have strong hepatoprotective effects. In this experiment, PPI network and KEGG pathway analysis were constructed by network pharmacological analysis technique using software and platforms such as Swiss, String, and David and Cytoscape. We screened AFB1 and DHM cross-targets and pathways of action, followed by molecular docking based on the strength of binding affinity of genes to DHM. In addition, we exposed AFB1 (200 μg/kg) to mice to establish a liver injury model. Histological observation, biochemical assay, oxidative stress indicator assay, TUNEL staining and Western blot were used to evaluate the liver injury. Network pharmacological results were screened to obtain 25 cross-targets of action and 20 pathways of action. It was found that DHM may exert anti-hepatic injury effects by inhibiting the overexpression of Caspase-3 protein and increasing the expression of Bcl-2 protein. DHM (200 mg/kg) was found to reduce AFB1-induced liver indices such as alanine aminotransferase (ALT) and aspartate acyltransferase (AST), and attenuate hepatic histopathological damage through animal models. Importantly, DHM inhibited malondialdehyde (MDA) formation in liver tissue and attenuated AFB1-induced oxidative stress injury by increasing glutathione-S-transferase (GST) glutathione (GPX) catalase (CAT) and superoxide dismutase (SOD). Meanwhile, DHM also restored the expression of anti-apoptotic protein Bcl-2 and antioxidant proteins, Nrf2, Keap1 and its downstream HO-1, and down-regulated the expression of pro-apoptotic proteins Bax and Caspase-3 in AFB1-induced liver tissues. The results confirmed that liver injury caused by AFB1 exposure could be alleviated by DHM, providing valuable guidance for in-depth study of DHM in the treatment of liver-related diseases, and laying the foundation for in-depth development and utilization of DHM.