PCV2 infection aggravates OTA-induced immunotoxicity in vivo and in vitro

In vitro and in vivo assessment of AFB1 and OTA toxic effects and the beneficial role of bioactive compounds. A systematic review

The purpose of this review was to investigate the current knowledge about aflatoxin B1 (AFB1) and ochratoxin A (OTA) toxicity and the possible beneficial role of bioactive compounds by using in vitro and in vivo models. Although AFB1 and OTA were tested in a similar percentage, the majority of studies focused on nephrotoxicity, hepatotoxicity, immune toxicity and neurotoxicity in which oxidative stress, inflammation, structural damage and apoptosis were the main mechanisms of action reported. Conversely, several biological compounds were assayed in order to modulate mycotoxins damage mainly in the liver, brain, kidney and immune system. Among them, pumpkin, curcumin and fermented whey were the most employed. Although a clear progress has been made by using in vivo models, further research is needed to assess not only the toxicity of multiple mycotoxins contamination but also the effect of functional compounds mixture, thereby reproducing more realistic situations for human health risk assessment.

Platycodon grandiflorus polysaccharide inhibits the inflammatory response of 3D4/21 cells infected with PCV2

Porcine circovirus type 2 (PCV2) infection cause multi-systemic inflammation in pigs. Platycodon grandiflorus polysaccharide (PGPSt) has been reported to have the effects of immune regulation and disease resistance. Nevertheless, the role and mechanism of PGPSt in the inflammatory response of 3D4/21 cells induced by PCV2 infection remain unclear. The present study aims to investigate effects of PGPSt on inflammatory response and its possible underlying mechanisms in vitro models. Cells were treated with PCV2 for 36 h to construct a cell inflammation model. The 3D4/21 cell lines were pretreated with or without PGPSt, and the changes of inflammation-related markers and the signaling pathway were detected by CCK-8, ELISA, qPCR and Western blot. The results showed that PGPSt was non-toxic to cells and protected PCV2-infected cells from inflammatory damage. PGPSt could significantly inhibit the high acetylation of histone H3 (AcH3) and histone H4 (AcH4), down-regulate HAT and up-regulate HDAC activity, and reduce the expression of pro-inflammatory enzymes iNOS and COX-2 proteins levels. Then the levels of IL-1β, IL-6 and TNF-α were significantly inhibited, and the level of IL-10 was promoted. We also observed that PGPSt inhibited the phosphorylation of p65, p38 and Erk1/2, which subsequently inhibited nuclear translocation of NF-κB p65 to express pro-inflammatory factors. In conclusion, PGPSt can reduce the inflammatory response by regulating histone acetylation, reducing the release of inflammatory factors, reducing the expression of pro-inflammatory enzymes, and inhibiting the activation of NF-κB and MAPKs signaling pathways. This suggests that PGPSt had an anti-inflammatory effect on the inflammatory response caused by PCV2 infection, which provided theoretical data support for the research.

Disruption of intestinal epithelial permeability in the Co-culture system of Caco-2/HT29-MTX cells exposed individually or simultaneously to acrylamide and ochratoxin A

Mycotoxins and thermal processing hazards are common contaminants in various foods and cause severe problems in terms of food safety and health. Combined use of acrylamide (AA) and ochratoxin A (OTA) would result in more significant intestinal toxicity than either toxin alone, but the underlying mechanisms behind this poor outcome remain unclear. Herein, we established the co-culture system of Caco-2/HT29-MTX cells for simulating a real intestinal environment that is more sensitive to AA and OTA, and showed that the combination of AA and OTA could up-regulate permeability of the intestine via increasing LY permeabilization, and decreasing TEER, then induce oxidative stress imbalance (GSH, SOD, MDA, and ROS) and inflammatory system disorder (TNF-α, IL-1β, IL-10, and IL-6), thereby leading a rapid decline in cell viability. Western blot, PAS- and AB-staining revealed that AA and OTA showed a synergistic effect on the intestine mainly through the disruption of tight junctions (TJs) and a mucus layer. Furthermore, based on correlation analysis, oxidative stress was more relevant to the mucus layer and TJs. Therefore, our findings provide a better evaluation model and a potential mechanism for further determining or preventing the combined toxicity caused by AA and OTA.

High-pressure acidified steaming with varied citric acid dosing can successfully detoxify mycotoxins

Mycotoxins are toxic fungal metabolites that exert various toxicities, including leading to death in lethal doses. This study developed a novel high-pressure acidified steaming (HPAS) for detoxification of mycotoxins in foods and feed. The raw materials, maize and peanut/groundnut, were used for the study. The samples were separated into raw and processed categories. Processed samples were treated using HPAS at different citric acid concentrations (CCC) adjusted to pH 4.0, 4.5, and 5.0. The enzyme-linked immunosorbent assay (ELISA) kit method for mycotoxins analysis was used to determine the levels of mycotoxins in the grains, with specific focus on total aflatoxins (AT), aflatoxins B1 (AFB1), aflatoxin G1 (AFG1), ochratoxin A (OTA), and citrinin. The mean values of the AT, AFB1, AFG1, OTA, and citrinin in the raw samples were 10.06 ± 0.02, 8.21 ± 0.01, 6.79 ± 0.00, 8.11 ± 0.02, and 7.39 ± 0.01 μg/kg for maize, respectively (p ≤ .05); and for groundnut (peanut), they were 8.11 ± 0.01, 4.88 ± 0.01, 7.04 ± 0.02, 6.75 ± 0.01, and 4.71 ± 0.00 μg/kg, respectively. At CCC adjusted to pH 5.0, the AT, AFB1, AFG1, OTA, and citrinin in the samples significantly reduced by 30%-51% and 17%-38% for maize and groundnut, respectively, and were reduced to 28%-100% when CCC was adjusted to pH 4.5 and 4.0 (p ≤ .05). The HPAS process either completely detoxified the mycotoxins or at least reduced them to levels below the maximum limits of 4.00-6.00, 2.00, 2.00, 5.00, and 100 μg/kg for AT, AFB1, AFG1, OTA, and citrinin, respectively, set by the European Union, WHO/FAO, and USDA. The study clearly demonstrates that mycotoxins can be completely detoxified using HPAS at CCC adjusted to pH 4.0 or below. This can be widely applied or integrated into many agricultural and production processes in the food, pharmaceutical, medical, chemical, and nutraceutical industries where pressurized steaming can be applied for the successful detoxification of mycotoxins.

Deoxynivalenol at No-Observed Adverse-Effect Levels Aggravates DSS-Induced Colitis through the JAK2/STAT3 Signaling Pathway in Mice

The etiology of inflammatory bowel diseases (IBDs) involves complex genetic and environmental factors such as mycotoxin contamination. Deoxynivalenol (DON), a well-known mycotoxin, contaminates food and feed and can induce intestinal injury and inflammatory response. The dose of DON in many foods is also below the limit, although the dose of DON exceeds the limit. The present study aims to evaluate the effects of the nontoxic dose of DON on colitis induced by dextran sodium sulfate (DSS) and the mechanism in mice. The results showed a nontoxic dose of DON at 50 μg/kg bw per day exacerbated DSS-induced colitis in mice as demonstrated by increased disease activity index, decreased colon length, increased morphological damage, decreased occludin and mucoprotein 2 expression, increased IL-1β and TNF-α expression, and decreased IL-10 expression. DON at 50 μg/kg bw per day enhanced JAK2/STAT3 phosphorylation induced by DSS. Adding JAK2 inhibitor AG490 attenuated the aggravating effects of DON on DSS-induced colitis by reversing the morphological damage, occludin and mucoprotein 2 expression increased, IL-1β and TNF-α expression increased, and IL-10 expression decreased. Taken together, a nontoxic dose of DON could aggravate DSS-induced colitis via the JAK2/STAT3 signaling pathway. This suggests that DON, below the standard limit dose, is also a risk for IBD and may be harmful to the health of humans and animals, which could provide the basis for establishing limits for DON.

Protective effect of selenomethionine on kidney injury induced by ochratoxin A in rabbits

The purpose of this study was to investigate the protective effect and mechanism of selenomethionine (SeMet) on ochratoxin A (OTA)-induced nephrotoxicity in rabbits. In total, sixty Ira rabbits were randomly divided into 5 groups (the control group, OTA group, 0. 2 mg/kg SeMet + OTA group, 0. 4 mg/kg SeMet + OTA group, and 0. 6 mg/kg SeMet + OTA group). The rabbits were fed diets supplemented with different doses of SeMet for 21 days and given 0. 2 mg/kg OTA starting on day 15 for a week. The results showed that the SeMet supplementation could improve the changes in blood physiological indices and renal function decline caused by OTA poisoning, and alleviate pathological kidney injury in the rabbits. SeMet also increased the activities of total antioxidant capacity, superoxide dismutase, and glutathione peroxidase, and decreased the contents of malondialdehyde and reactive oxygen species and the expression of interleukin-1β, interleukin-6, and tumor necrosis factor-α in the damaged kidneys of the rabbits. In addition, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream gene heme oxygenase 1 (HO-1) was also inhibited after OTA poisoning, while SeMet activated the Nrf2 signaling pathway and enhanced the expression of Nrf2 and the downstream gene HO-1. In conclusion, SeMet protected against kidney injury caused by OTA in rabbits, and the mechanism may be the activation of the Nrf2 signaling pathway.

Mycotoxins and cellular senescence: the impact of oxidative stress, hypoxia, and immunosuppression

Mycotoxins induce oxidative stress, hypoxia, and cause immunosuppressive effects. Moreover, emerging evidence show that mycotoxins have a potential of inducing cellular senescence, which are involved in their immunomodulatory effects. Mycotoxins upregulate the expression of senescence markers γ-H2AX, senescence-associated β-galactosidase, p53, p16, and senescence-associated secretory phenotype (SASP) inflammatory factors. Moreover, mycotoxins cause senescence-associated cell cycle arrest by diminishing cyclin D₁ and Cdk4 pathways, as well as increasing the expression of p53, p21, and CDK6. Mycotoxins may induce cellular senescence by activating reactive oxygen species (ROS)-induced oxidative stress. In addition, hypoxia acts as a double-edged sword on cell senescence; it could both act as the stress-induced senescence and also hinder the onset of cellular senescence. The SASP inflammatory factors have the ability to induce an immunosuppressive environment, while mycotoxins directly cause immunosuppression. Therefore, there is a potential relationship between mycotoxins and cellular senescence that synergistically cause immunosuppression. However, most of the current studies have involved the effect of mycotoxins on cell cycle arrest, but only limited in-depth research has been carried out to link the occurrence of this condition (cell cycle arrest) with cellular senescence.

Protective and detoxifying effects conferred by selenium against mycotoxins and livestock viruses: A review

Animal feed can easily be infected with molds during production and storage processes, and this can lead to the production of secondary metabolites, such as mycotoxins, which eventually threaten human and animal health. Furthermore, livestock production is also not free from viral infections. Under these conditions, the essential trace element, selenium (Se), can confer various biological benefits to humans and animals, especially due to its anticancer, antiviral, and antioxidant properties, as well as its ability to regulate immune responses. This article reviews the latest literature on the antagonistic effects of Se on mycotoxin toxicity and viral infections in animals. We outlined the systemic toxicity of mycotoxins and the primary mechanisms of mycotoxin-induced toxicity in this analysis. In addition, we pay close attention to how mycotoxins and viral infections in livestock interact. The use of Se supplementation against mycotoxin-induced toxicity and cattle viral infection was the topic of our final discussion. The coronavirus disease 2019 (COVID-19) pandemic, which is currently causing a health catastrophe, has altered our perspective on health concerns to one that is more holistic and increasingly embraces the One Health Concept, which acknowledges the interdependence of humans, animals, and the environment. In light of this, we have made an effort to present a thorough and wide-ranging background on the protective functions of selenium in successfully reducing mycotoxin toxicity and livestock viral infection. It concluded that mycotoxins could be systemically harmful and pose a severe risk to human and animal health. On the contrary, animal mycotoxins and viral illnesses have a close connection. Last but not least, these findings show that the interaction between Se status and host response to mycotoxins and cattle virus infection is crucial.