Effects of compound probiotics and aflatoxin-degradation enzyme on alleviating aflatoxin-induced cytotoxicity in chicken embryo primary intestinal epithelium, liver and kidney cells

Compound probiotics regulate the NRF2 antioxidant pathway to inhibit aflatoxin B1-induced autophagy in mouse Sertoli TM4 cells

This study investigated the effects of compound probiotics (CP) on AFB1-induced cytotoxicity in Sertoli TM4 cells. The L9 (3 × 3) orthogonal test was conducted to determine the optimal CP required for high AFB1 degradation in the artificial gastrointestinal fluid in vitro. The maximal AFB1 degradation rate was 40.55 % (P < 0.05) when the final viable count was 1.0 × 105 CFU/mL for Bacillus subtilis, Lactobacillus casein, and Saccharomyces cerevisiae. The effects of CP and the CP supernatant (CPS) on TM4 cell viability were evaluated to achieve the optimal protective conditions. When CPS4 (corresponding to CP viable counts of 1.0 × 104 CFU/mL) was added to the TM4 cells for 24 h, the cell viability reached 108.86 % (P < 0.05). AFB1 reduced TM4 cell viability in a concentration- and time-dependent manner at an AFB1 concentration ranging from 0 to 1.5 μM after 48-h AFB1 exposure. The optimal AFB1 concentration/times for low- and high damage models were 0.5 and 1.25 μM both for 24 h, which decreased viability to 76.04 % and 65.35 %, respectively. however, CPS4 added to low- and high-damage models increased the cell viability to 97.43 % and 75.12 %, respectively (P < 0.05). Transcriptome sequencing was performed based on the following designed groups: the control, 0.5 μM AFB1, 1.25 μM AFB1, CPS4, and CPS4+0.5 μM AFB1. The Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis was further performed to identify significantly enriched signaling pathways, which were subsequently verified. It was shown that AFB1 induced apoptosis by blocking the PI3K-AKT-mTOR pathway and upregulating autophagy proteins such as LC3B, Beclin1, and ATG5 while inhibiting autophagic flux. CPS4 promoted AFB1 degradation, activated the p62-NRF2 antioxidant, and inhibited ROS/TRPML1 pathways, thereby reducing ROS production and inflammation and ultimately alleviating AFB1-induced autophagy and apoptosis. These findings supports the potential of probiotics to protect the male reproductive system from toxin damage.

Therapeutic Effect of Natural Products and Dietary Supplements on Aflatoxin-Induced Nephropathy

Aflatoxins are harmful natural contaminants found in foods and are known to be hepatotoxic. However, recent studies have linked chronic consumption of aflatoxins to nephrotoxicity in both animals and humans. Here, we conducted a systematic review of active compounds, crude extracts, herbal formulations, and probiotics against aflatoxin-induced renal dysfunction, highlighting their mechanisms of action in both in vitro and in vivo studies. The natural products and dietary supplements discussed in this study alleviated aflatoxin-induced renal oxidative stress, inflammation, tissue damage, and markers of renal function, mostly in animal models. Therefore, the information provided in this review may improve the management of kidney disease associated with aflatoxin exposure and potentially aid in animal feed supplementation. However, future research is warranted to translate the outcomes of this study into clinical use in kidney patients.

Chronic exposure to aflatoxin B1 increases hippocampal microglial pyroptosis and vulnerability to stress in mice

BACKGROUND

Chronic aflatoxin B1 (AFB1) exposure may increase the risk of multiple neuropsychiatric disorders. Stress is considered one of the main contributors to major depressive disorder. Whether and how chronic AFB1 exposure affects vulnerability to stress is unclear.

METHODS

Mice were exposed for three weeks to AFB1 (100 µg/kg/d) and/or chronic mild stress (CMS). The vulnerability behaviors in response to stress were assessed in the forced swimming test (FST), sucrose preference test (SPT), and tail suspension test (TST). Microglial pyroptosis was investigated using immunofluorescence, enzyme-linked immunosorbent assays, and western blot assay in the hippocampus of mice. Hippocampal neurogenesis and the effects of AFB1-treated microglia on proliferation and differentiation of neural stem/precursor cells (NSPCs) were assessed via immunofluorescence in the hippocampus of mice.

RESULTS

Mice exposed to CMS in the presence of AFB1 exhibited markedly greater vulnerability to stress than mice treated with CMS or AFB1 alone, as indicated by reduced sucrose preference and longer immobility time in the forced swimming test. Chronic aflatoxin B1 exposure resulted in changes in the microglial morphology and increase in TUNEL⁺ microglia and GSDMD⁺ microglia in the hippocampal dentate gyrus. When mice were exposed to both CMS and AFB1, pyroptosis-related molecules (such as NLRP3, caspase-1, GSDMD-N, and interleukin-1β) were significantly upregulated in the hippocampus. These molecules were also significantly enhanced by AFB1 in primary microglial cultures. AFB1-treated mice showed decrease in the numbers of BrdU⁺, BrdU-DCX⁺, and BrdU-NeuN⁺ cells in the hippocampal dentate gyrus, as well as the percentages of BrdU⁺ cells that were NeuN⁺ in the presence or absence of CMS when compared with vehicle-treated mice. The combination of AFB1 and CMS exacerbated these effects to an even greater extent. The number of DCX⁺ cells correlated negatively with the percentage of ameboid microglia, TUNEL⁺ microglia and GSDMD⁺ microglia in the hippocampal dentate gyrus. AFB1-treated microglia suppressed the proliferation and neuronal differentiation of NSPCs in vitro.

CONCLUSION

Chronic AFB1 exposure induces microglial pyroptosis, promoting an adverse neurogenic microenvironment that impairs hippocampal neurogenesis, which may render mice more vulnerable to stress.

Blunting ROS/TRPML1 pathway protects AFB1-induced porcine intestinal epithelial cells apoptosis by restoring impaired autophagic flux

Aflatoxin B1 (AFB1) is a stable mycotoxin that contaminates animal feed on a large scale and causes severe damage to intestinal cells, induces inflammation and stimulates autophagy. Transient receptor potential mucolipin subfamily 1 (TRPML1) is a regulatory factor of autophagy, but the underlying mechanisms of TRPML1-mediated autophagy in AFB1 intestine toxicity remain elucidated. In the present study, AFB1 (0, 5, 10 μg/mL) was shown to reduce cell viability, increase reactive oxygen species (ROS) accumulation and apoptosis rate. Additionally, AFB1 caused structural damage to mitochondria and lysosomes and increased autophagosomes numbers. Furthermore, AFB1 promoted Ca²⁺ release by activating the TRPML1 channel, stimulated the expression of autophagy-related proteins, and induced autophagic flux blockade. Moreover, pharmacological inhibition of autophagosome formation by 3-methyladenine attenuated AFB1-induced apoptosis by downregulating the levels of TRPML1 and ROS, whereas blockade of autophagosome-lysosomal fusion by chloroquine alleviated AFB1-induced apoptosis by upregulating TRPML1 expression and exacerbating ROS accumulation. Intriguingly, blocking AFB1-induced autophagic flux generated ROS- and TRPML1-dependent cell death, as shown by the decreased apoptosis in the presence the free radical scavenger N-Acetyl-L-cysteine and the TRPML1 inhibitor ML-SI1. Overall, these results showed that AFB1 promoted apoptosis of IPEC-J2 cells by disrupting autophagic flux through activation of the ROS/TRPML1 pathway.

Aflatoxin B1 damaged structural barrier through Keap1a/Nrf2/ MLCK signaling pathways and immune barrier through NF-κB/ TOR signaling pathways in gill of grass carp (Ctenopharyngodon idella)

Aquafeeds are susceptible to contamination caused by aflatoxin B1 (AFB1). The gill of fish is an important respiratory organ. However, few studies have investigated the effects of dietary AFB1 exposure on gill. This study aimed to discuss the effects of AFB1 on the structural and immune barrier of grass carp gill. Dietary AFB1 increased reactive oxygen species (ROS) levels, protein carbonyl (PC) and malondialdehyde (MDA) contents, which consequently caused oxidative damage. In contrast, dietary AFB1 decreased antioxidant enzymes activities, relative genes expression (except MnSOD) and the contents of glutathione (GSH) (P < 0.05), which are partly regulated by NF-E2-related factor 2 (Nrf2/Keap1a). Moreover, dietary AFB1 caused DNA fragmentation. The relative genes of apoptosis (except Bcl-2, McL-1 and IAP) were significantly upregulated (P < 0.05), and apoptosis was likely upregulated through p38 mitogen-activated protein kinase (p38MAPK). The relative expressions of genes associated with tight junction complexes (TJs) (except ZO-1 and claudin-12) were significantly decreased (P < 0.05), and TJs were likely regulated by myosin light chain kinase (MLCK). Overall, dietary AFB1 disrupted the structural barrier of gill. Furthermore, AFB1 increased gill sensitivity to F. columnare, increased Columnaris disease and decreased the production of antimicrobial substances (P < 0.05) in grass carp gill, and upregulated the expression of genes involved with pro-inflammatory factors (except TNF-α and IL-8) and the pro-inflammatory response partly attributed to the regulation by nuclear factor κB (NF-κB). Meanwhile, the anti-inflammatory factors were downregulated (P < 0.05) in grass carp gill after challenge with F. columnare, which was partly attributed to the target of rapamycin (TOR). These results suggested that AFB1 aggravated the disruption of the immune barrier of grass carp gill after being challenge with F. columnare. Finally, the upper limit of safety of AFB1 for grass carp, based on Columnaris disease, was 31.10 μg/kg diet.

Protective efficacy of luteolin against aflatoxinB1-induced toxicity, oxidative damage, and apoptosis in the rat liver

One particularly harmful mycotoxin, aflatoxin B1 (AFB₁), usually triggers liver toxicity and oxidative stress in both humans and other mammals. Luteolin (LUTN), a popular active phytochemical molecule, exhibits a strong antioxidant potential. The purpose of this investigation was to explore the potential molecular mechanism in rats and determine if LUTN exhibits protective benefits against AFB₁-induced hepatotoxicity. Random selection was used to determine the four treatment groups, each consisting of 24 rats (n = 6). Physiological saline was administered to group 1 (CONT); group 2 received LUTN for a dosage of 50-mg/kg BW. AFB₁ was administered to group 3 for a dosage of 0.75-mg/kg BW, and AFB₁ with LUTN was given to group 4 at the same dosages mentioned in the previous groups. Rats intoxicated with AFB₁ alterations of hepatic transaminases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), displayed periportal mononuclear cell infiltrations, disorganized lobular architecture, and dispersed necrotic cells in their liver tissues. By reducing serum biochemical levels of the hepatic transaminases ALT and AST brought on by AFB₁ exposure, our results demonstrated that LUTN treatment considerably restored liver injury. Through lowering the production of malondialdehyde (MDA) and reactive oxygen species (ROS), as well as by boosting the activity of the antioxidant enzyme catalase (CAT) and superoxide dismutase (SOD), LUTN mitigated the oxidative stress brought on by AFB₁. Our findings showed that LUTN significantly reversed the liver damage caused by AFB₁. When considered as a whole, LUTN may protect the liver from damage brought on by AFB₁ by acting as a potential mitigator and may aid in the creation of cutting-edge therapies to treat liver illnesses in humans and/or animals.

Compound mycotoxin detoxifier alleviating aflatoxin B1 toxic effects on broiler growth performance, organ damage and gut microbiota

The aim of this study was to evaluate the effects of compound mycotoxin detoxifier (CMD) on alleviating the toxic effect of aflatoxin B₁ (AFB₁) for broiler growth performance. One-kilogram CMD consists of 667 g aflatoxin B₁-degrading enzyme (ADE, 1,467 U/g), 200 g montmorillonite and 133 g compound probiotics (CP). The feeding experiment was divided into 2 stages (1-21 d and 22-42 d). In the early stage, a total of 300 one-day-old Ross broilers were randomly divided into 6 groups, 5 replications for each group, 10 broilers (half male and half female) in each replication. In the later feeding stage, about 240 twenty-two-day-old Ross broilers were randomly divided into 6 groups, 8 replications for each group, 5 broilers in each replication. Group A: basal diet; group B: basal diet with 40 μg/kg AFB₁; group C: basal diet with 1 g/kg CMD; groups D, E, and F: basal diet with 40 μg/kg AFB₁ plus 0.5, 1.0 and 1.5 g/kg CMD, respectively. The results indicated that AFB₁ significantly decreased average daily gain (ADG), protein metabolic rate, organ index of thymus, bursa of Fabricius (BF), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and catalase activities in serum, and increased AFB₁ residues in serum and liver (P < 0.05). Hematoxylin-Eosin (HE) staining analysis of jejunum, liver and kidney showed that AFB₁ caused the main pathological changes with different degrees of inflammatory cell infiltration. However, CMD additions could alleviate the negative effects of AFB₁ on the above parameters. The gut microbiota analysis indicated that AFB₁ could significantly increase the abundances of Staphylococcus-xylosu, Esherichia-coli-g-Escherichia-Shigella, and decrease Lactobacillus-aviarius abundance (P < 0.05), but which were adjusted to almost the same levels as the control group by CMD addition. The correlative analysis showed that Lactobacillus-aviarius abundance was positively correlated with ADG, SOD and BF (P < 0.05), whereas Staphylococcus-xylosus abundance was positively correlated with AFB₁ residues in serum and liver (P < 0.05). In conclusion, CMD could keep gut microbiota stable, alleviate histological lesions, increase growth performance, and reduce mycotoxin toxicity. The optimal CMD addition should be 1 g/kg in AFB₁-contaminated broilers diet.

Dietary Aflatoxin B1 attenuates immune function of immune organs in grass carp (Ctenopharyngodon idella) by modulating NF-κB and the TOR signaling pathway

Aflatoxin B1 (AFB1) is kind of a common mycotoxin in food and feedstuff. Aquafeeds are susceptible to contamination of AFB1. In teleost fish, the spleen and head kidney are key immune organ. Moreover, the fish skin is a critical mucosal barrier system. However, there was little study on the effects of dietary AFB1 on the immune response of these immune organs in fish. This study aimed to explore the impacts of oral AFB1 on the immune competence and its mechanisms in the skin, spleen, and head kidney of grass carp. Our work indicated that dietary AFB1 reduced antibacterial compounds and immunoglobulins contents, and decreased the transcription levels of antimicrobial peptides in grass carp immune organs. In addition, dietary AFB1 increased the transcription levels of pro-inflammatory cytokines and reduced the transcription levels of anti-inflammatory cytokines in the grass carp immune organs, which might be regulated by NF-κB and TOR signaling, respectively. Meanwhile, we evaluated the content of AFB1 in the grass carp diet should not exceed 29.48 μg/kg diet according to the levels of acid phosphatase and lysozyme. In summary, dietary AFB1 impaired immune response in grass carp skin, spleen, and head kidney.

Potential application of probiotics in mycotoxicosis reduction in mammals and poultry

Mycotoxins in feedstuffs are considered as a principal worry by food safety authorities worldwide because most of them can be transferred from the feed to food commodities of animal origin, and further consumed by humans. Therefore, effective alternatives for the reduction of the impact of mycotoxins need to be applied in the feed production industry. Applications of beneficial microorganisms (probiotics) can be alternative and applied as feed additives in order to reduce or eliminate the toxic effects of mycotoxins on animals. The aim of this article is to provide information on the role of beneficial microorganisms (probiotics) and point out their role in the reduction of the effect of mycotoxin toxicity in farming animals (mammals and poultry). The objective was to provide a summary of the existing knowledge based on the application of different strains belonging to the group of lactic acid bacteria (LAB) or yeasts that are already or can be future employed in the feed industry, in order to reduce mycotoxicosis presence in mammals and poultry exposed to mycotoxin-contaminated feed. Moreover, an overview of mycotoxins toxicity in mammals and poultry will be presented, and furthermore, the role of the beneficial microorganisms (including probiotics) in the reduction of mycotoxins toxicity (aflatoxicosis, deoxynivalenol, zearalenone, ochratoxin A, and fumonisin toxicities) will be described in detail.

Effects of Compound Mycotoxin Detoxifier on Alleviating Aflatoxin B1-Induced Inflammatory Responses in Intestine, Liver and Kidney of Broilers

In order to alleviate the toxic effects of aflatoxins B1 (AFB1) on inflammatory responses in the intestine, liver, and kidney of broilers, the aflatoxin B1-degrading enzyme, montmorillonite, and compound probiotics were selected and combined to make a triple-action compound mycotoxin detoxifier (CMD). The feeding experiment was divided into two stages. In the early feeding stage (1−21 day), a total of 200 one-day-old Ross broilers were randomly divided into four groups; in the later feeding stage (22−42 day), 160 broilers aged at 22 days were assigned to four groups: Group A: basal diet (4.31 μg/kg AFB1); Group B: basal diet with 40 μg/kg AFB1; Group C: Group A plus 1.5 g/kg CMD; Group D: Group B plus 1.5 g/kg CMD. After the feeding experiment, the intestine, liver, and kidney tissues of the broilers were selected to investigate the molecular mechanism for CMD to alleviate the tissue damages. Analyses of mRNA abundances and western blotting (WB) of inflammatory factors, as well as immunohistochemical (IHC) staining of intestine, liver, and kidney tissues showed that AFB1 aggravated the inflammatory responses through NF-κB and TN-α signaling pathways via TLR pattern receptors, while the addition of CMD significantly inhibited the inflammatory responses. Phylogenetic investigation showed that AFB1 significantly increased interleukin-1 receptor-associated kinase (IRAK-1) and mitogen-activated protein kinase (MAPK) activities (p < 0.05), which were restored to normal levels by CMD addition, indicating that CMD could alleviate cell inflammatory damages induced by AFB1.

Evaluation of the Role of Probiotics As a New Strategy to Eliminate Microbial Toxins: a Review

Probiotics are living microorganisms that have favorable effects on human and animal health. The most usual types of microorganisms recruited as probiotics are lactic acid bacteria (LAB) and bifidobacteria. To date, numerous utilizations of probiotics have been reported. In this paper, it is suggested that probiotic bacteria can be recruited to remove and degrade different types of toxins such as mycotoxins and algal toxins that damage host tissues and the immune system causing local and systemic infections. These microorganisms can remove toxins by disrupting, changing the permeability of the plasma membrane, producing metabolites, inhibiting the protein translation, hindering the binding to GTP binding proteins to GM1 receptors, or by preventing the interaction between toxins and adhesions. Here, we intend to review the mechanisms that probiotic bacteria use to eliminate and degrade microbial toxins.

Effects of Lactobacillus salivarius supplementation on the growth performance, liver function, meat quality, immune responses and Salmonella Pullorum infection resistance of broilers challenged with Aflatoxin B1

Aflatoxin B1 (AFB1) is one of the most toxic mycotoxins. It has been reported that dietary exposure to AFB1 is related to the low growth performance, immunosuppression, and high susceptibility to infectious diseases of chickens. The aim of the present study was to evaluate the protective effects of Lactobacillus salivarius on broiler chickens challenged with AFB1. First, AFB1 degradation ability of Lactobacillus salivarius was measured by a high-performance liquid chromatography (HPLC) method. Then, the Arbor Acres broiler chickens were randomly assigned to experimental groups. The effects of Lactobacillus salivarius supplementation on the growth performance, liver function, and meat quality were measured, and immune response was also determined after vaccination with attenuated infectious bursal disease virus (IBDV) vaccine of broilers challenged with AFB1. Besides, resistance to Salmonella Pullorum infection along with AFB1 exposure was determined in broilers. The results showed that Lactobacillus salivarius could effectively degrade AFB1. Lactobacillus salivarius supplementation improved growth performance, liver function, and meat quality of broilers challenged with AFB1. In addition, Lactobacillus salivarius supplementation resulted in enhanced specific antibody and IFN-γ production, and lymphocyte proliferation in broilers challenged with AFB1 after IBDV vaccine immunization. Furthermore, Lactobacillus salivarius supplementation enhanced Salmonella Pullorum infection resistance in broilers challenged with AFB1. Our results revealed a tremendous potential of Lactobacillus salivarius as feed additive to degrading AFB1 and increasing broilers production performance in poultry production.

Detoxification of aflatoxin B1 in broiler chickens by a triple-action feed additive

The aim of this study was to evaluate the detoxification of aflatoxin B₁ (AFB₁) in vitro and in broiler chickens using a triple-action compound mycotoxin detoxifier (CMD). Response surface methodology (RSM) was used to evaluate AFB1 detoxification in artificial gastrointestinal fluid (AGIF) in vitro. The AFB₁-degradation rate was 41.5% (P < .05) when using a compound probiotic (CP) in which the visible counts of Bacillus subtilis, Lactobacillus casein, Enterococcus faecalis and Candida utilis were 1.0 × 10⁵, 1.0 × 10⁵, 1.0 × 10⁷ and 1.0 × 10⁵ CFU/mL, respectively. When CP was combined with 0.1% AFB₁-degrading enzyme to give CPADE, the AFB₁-degradation rate was increased to 55.28% (P < .05). The AFB₁-removal rate was further increased to above 90% when CPADE was combined with 0.03% montmorillonite to make CMD. In vivo, a total of 150 one-day-old Ross broilers were allotted to 3 groups, 5 replications for each group, 10 broilers in each replication. Group A: basal diet, Group B: basal diet with 40 μg/kg AFB₁, Group C: basal diet with 40 μg/kg AFB₁ plus CMD. The feeding experiment period was 21 d. The results showed that broiler growth was increased, and AFB₁ residues in serum, excreta and liver were decreased by CMD addition in broiler diet (P < .05). In conclusion, CMD was able to remove AFB₁ efficiently in vitro and to increase broiler production performance and reduce AFB₁ residues in the chickens.