Lactobacillus plantarum MON03 counteracts zearalenone génotoxicty in mice: Chromosome aberrations, micronuclei, DNA fragmentation and apoptotique gene expression

AFM1 exposure in male balb/c mice and intervention strategies against its immuno-physiological toxicity using clay mineral and lactic acid bacteria alone or in combination

CONTEXT

Aflatoxins are the most harmful mycotoxins that cause human and animal health concerns. Aflatoxin M1 (AFM1) is the primary hydroxylated metabolite of aflatoxin B1 and is linked to the development of hepatocellular carcinoma and immunotoxicity in humans and animals. Because of the important role of dairy products in human life, especially children, AFM1 is such a major concern to humans because of its frequent occurrence in dairy products at concentrations high enough to cause adverse effects to human and animal health. Reduced its bioavailability becomes a high priority in order to protect human and animal health.

OBJECTIVES

This study aimed to investigate, in vivo, the ability of lactic acid bacteria (lactobacillus rhamnosus GAF01, LR) and clay mineral (bentonite, BT) mixture to mitigate/reduce AFM1-induced immunotoxicity, hepatotoxicity, nephrotoxicity and oxidative stress in exposed Balb/c mice.

MATERIALS AND METHODS

The in vivo study was conducted using male Balb/c mice that treated, orally, by AFM1 alone or in combination with LR and/or BT, daily for 10 days as follows: group 1 control received 200 µl of PBS, group 2 treated with LR alone (2.108 CFU/mL), group 3 treated with BT alone (1 g/kg bw), group 4 treated with AFM1 alone (100 μg/kg), group 5 co-treated with LR + AFM1, group 6 co-treated with BT + AFM1, group 7 co-treated with BT + LR + AFM1. Forty-eight h after the end of the treatment, the mice were sacrificed and the blood, spleen, thymus, liver and kidney were collected. The blood was used for biochemical and immunological study. Spleen and thymus samples were used to thymocytes and splenocytes assessments. Liver and kidney samples were the target for evaluation of oxidative stress enzymes status and for histological assays.

RESULTS

The results showed that AFM1 caused toxicities in male Blab/c mice at different levels. Treatment with AFM1 resulted in severe stress of liver and kidney organs indicated by a significant change in the biochemical and immunological parameters, histopathology as well as a disorder in the profile of oxidative stress enzymes levels. Also, it was demonstrated that AFM1 caused toxicities in thymus and spleen organs. The co-treatment with LR and/or BT significantly improved the hepatic and renal tissues, regulated antioxidant enzyme activities, spleen and thymus viability and biochemical and immunological parameters. LR and BT alone showed to be safe during the treatment.

CONCLUSION

In summary, the LR and/or BT was able to reduce the biochemical, histopathological and immunological damages induced by AFM1 and indeed it could be exploited as one of the biological strategies for food and feedstuffs detoxification.

MicotoXilico: An Interactive Database to Predict Mutagenicity, Genotoxicity, and Carcinogenicity of Mycotoxins

Mycotoxins are secondary metabolites produced by certain filamentous fungi. They are common contaminants found in a wide variety of food matrices, thus representing a threat to public health, as they can be carcinogenic, mutagenic, or teratogenic, among other toxic effects. Several hundreds of mycotoxins have been reported, but only a few of them are regulated, due to the lack of data regarding their toxicity and mechanisms of action. Thus, a more comprehensive evaluation of the toxicity of mycotoxins found in foodstuffs is required. In silico toxicology approaches, such as Quantitative Structure-Activity Relationship (QSAR) models, can be used to rapidly assess chemical hazards by predicting different toxicological endpoints. In this work, for the first time, a comprehensive database containing 4360 mycotoxins classified in 170 categories was constructed. Then, specific robust QSAR models for the prediction of mutagenicity, genotoxicity, and carcinogenicity were generated, showing good accuracy, precision, sensitivity, and specificity. It must be highlighted that the developed QSAR models are compliant with the OECD regulatory criteria, and they can be used for regulatory purposes. Finally, all data were integrated into a web server that allows the exploration of the mycotoxin database and toxicity prediction. In conclusion, the developed tool is a valuable resource for scientists, industry, and regulatory agencies to screen the mutagenicity, genotoxicity, and carcinogenicity of non-regulated mycotoxins.

Crosstalk between Mycotoxins and Intestinal Microbiota and the Alleviation Approach via Microorganisms

Mycotoxins are secondary metabolites produced by fungus. Due to their widespread distribution, difficulty in removal, and complicated subsequent harmful by-products, mycotoxins pose a threat to the health of humans and animals worldwide. Increasing studies in recent years have highlighted the impact of mycotoxins on the gut microbiota. Numerous researchers have sought to illustrate novel toxicological mechanisms of mycotoxins by examining alterations in the gut microbiota caused by mycotoxins. However, few efficient techniques have been found to ameliorate the toxicity of mycotoxins via microbial pathways in terms of animal husbandry, human health management, and the prognosis of mycotoxin poisoning. This review seeks to examine the crosstalk between five typical mycotoxins and gut microbes, summarize the functions of mycotoxins-induced alterations in gut microbes in toxicological processes and investigate the application prospects of microbes in mycotoxins prevention and therapy from a variety of perspectives. The work is intended to provide support for future research on the interaction between mycotoxins and gut microbes, and to advance the technology for preventing and controlling mycotoxins.

Toxicity of zearalenone and its nutritional intervention by natural products

Zearalenone (ZEN) is a toxic secondary metabolite mainly produced by fungi of the genus Fusarium, and is often present in various food and feed ingredients such as corn and wheat. The structure of ZEN is similar to that of natural estrogen, and it can bind to estrogen receptors and has estrogenic activity. Therefore, it can cause endocrine-disrupting effects and promote the proliferation of estrogen receptor-positive cell lines. In addition, ZEN can cause oxidative damage, endoplasmic reticulum stress, apoptosis, and other hazards, resulting in systemic toxic effects, including reproductive toxicity, hepatotoxicity, and immunotoxicity. In the past few decades, researchers have tried many ways to remove ZEN from food and feed, but it is still a challenge to eliminate it. In recent years, natural compounds have become of interest for their excellent protective effects on human health from food contaminants. Researchers have discovered that natural compounds often used as dietary supplements can effectively alleviate ZEN-induced systemic toxic effects. Most of the compounds mitigate ZEN-induced toxicity through antioxidant effects. In this article, the contamination of food and feed by ZEN and the various toxic effects and mechanisms of ZEN are reviewed, as well as the mitigation effects of natural compounds on ZEN-induced toxicity.

Costus speciosus extract protects against the oxidative damage of zearalenone via modulation of inflammatory cytokines, Nrf2 and iNOS gene expression in rats

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin that induces severe health disturbances in humans and animals. This study aimed to determine the bioactive compounds in Costus speciosus extract (CSE) using GC-MS and evaluate its protective capability against ZEN-induced oxidative damage, genotoxicity, and cytotoxicity in rats. Six groups of male Sprague Dawley rats were treated orally for 15 days including the control group, CSE-treated groups at low (200 mg/kg b. w) or high (400 mg/kg b. w) dose, ZEN-treated group (40 μg/kg b. w), and the groups treated with ZEN plus the low or the high dose of CSE. Blood and tissue samples were collected for different assays and pathological analyses. The results of GC-MS indicated the identification of 6 compounds and Azulene was the major. Animals that received ZEN showed severe disturbances in serum biochemical, cytokines, oxidative stress indicators, mRNA expression of iNOS, Nrf2, and inflammatory-related genes. ZEN also increased micronucleated polychromatic erythrocytes (MNPCEs) and comet tail formation in bone marrow cells along with the disturbances in the histological architecture of the liver and kidney. Co-administration of CSE plus ZEN could normalize the majority of the tested parameters and the histological picture at a dose as low as 200 mg/kg b. w. Therefore, CSE protects against ZEN toxicity via its antioxidant activity, modulation of iNOS, inflammatory-related genes, and the Nrf2 pathway and it could be used in the endemic regions.

Oxidative stress as a plausible mechanism for zearalenone to induce genome toxicity

Zearalenone (ZEN), a common non-steroidal estrogenic mycotoxin of the Fusarium genus, is one of the most frequent and powerful contaminant of grains and cereal products representing a serious threat for people and livestock health. In fact, ZEN causes cytotoxicity and genotoxicity in a variety of cell types at least in part through binding to estrogen receptors (ERs). The main pathways through which ZEN induces such effects remain, however, elusive. In particular, how the mycotoxin causes DNA damage, dysregulates DNA repair mechanisms, changes epigenome of targeted cells and, not least, affects chromatin conformation and non-coding RNA (ncRNA), is unclear. In the present paper, following extensive review of the literature about such ZEN effects and our own experience in studying the effects of this compound on reproductive processes, we propose that increased production of reactive oxygen species (ROS) and consequently oxidative stress (OS) are central in ZEN genotoxicity. Besides to shed light on the action mechanisms of the mycotoxin, this notion might help to develop effective strategies to counteract its deleterious biological effects.

Potential protective effect of lactic acid bacteria against zearalenone causing reprotoxicity in male mice

Zearalenone (ZEN) is a worldwide fusarotoxin that poses a threat to the consumer due to its chronic toxicity. Herein we examined the effects of ZEN on adult mouse testis, focusing on oxidative stress, biochemical and morphological parameters. In addition, since cytoskeletal remodeling is a key event for the production of good quality gametes, the expression and localization of two proteins, Dishevelled-associated activator of morphogenesis 1 (DAAM1) and Prolyl endopeptidase (PREP), involved in cytoskeletal dynamics during spermatogenesis were evaluated. To ameliorate the testicular dysfunction induced by ZEN we tested the eventual protective effects of lactic bacteria Lactobacillus plantarum MON03 (LP) on its reprotoxicity. Adult male mice were then treated daily for 2 wks by oral gavage with ZEN and/or LP. The results confirmed that ZEN altered sperm parameters, generated oxidative stress and provoked structural alteration, evidenced by the increased number of abnormal seminiferous tubules and of apoptotic cells, particularly Leydig cells. Interestingly, at molecular level we evaluated, for the first time, the ability of ZEN to alter DAAM1 and PREP protein level and localization. Moreover, the co-treatment with LP, thanks to its capacity to reduce ZEN bioavailability in the gastrointestinal tract, ameliorated all the considered parameters. These results suggest the use of this probiotic as food supplement to prevent/counteract ZEN-induced reprotoxicity.

Assessment of water quality of selected rivers in the Niger Delta region of Nigeria using biomarkers in Clarias gariepinus

Petroleum exploration has continued to impact negatively the Niger Delta region of Nigeria. Oil spills from petroleum exploration contaminate both the aquatic and non- aquatic environments and destroy the ecosystem which makes people in these regions to be prone to diseases such as cancer, cardiovascular diseases, neurodegenerative disease, infertility, and sterility and also poverty. Some oxidative stress markers of the liver and muscle of fish (Clarias gariepinus) from Apata, Araromi, and Mahin rivers (located in the Niger Delta region) were compared with those of fish samples from a clean fish farm (control) in order to assess the level of pollution of the rivers. A significant increase in malondialdehyde level and myeloperoxidase (MPO) activity as well as alterations in antioxidant status (glutathione peroxidase, superoxide dismutase, reduced glutathione, and glutathione S-transferase) was observed in the organs of fish samples from Apata, Araromi, and Mahin rivers compared with the control. A significant increase in the frequency of micronucleated polychromatic erythrocytes (MnPCEs) was also observed in the fish samples from these rivers in comparison with the control. Based on results of our research, we can conclude that these rivers are polluted mainly by oil spillage and other industrial activities; therefore, the consumption of aquatic organisms from these rivers and the use of water from the rivers for domestic activities might be unsafe.

Genotoxic effects of mycotoxins

Fungi produce mycotoxins in the presence of appropriate temperature, humidity, sufficient nutrients and if the density of the mushroom mass is favorable. Although all mycotoxins are of fungal origin, all toxic compounds produced by fungi are not called mycotoxins. The interest in mycotoxins first started in the 1960s, and today the interest in mycotoxin-induced diseases has increased. To date, 400 mycotoxins have been identified and the most important species producing mycotoxins belongs to Aspergillus, Penicillium, Alternaria and Fusarium genera. Mycotoxins are classified as hepatotoxins, nephrotoxins, neurotoxins, immunotoxins etc. In this review genotoxic and also other health effects of some major mycotoxin groups like Aflatoxins, Ochratoxins, Patulin, Fumonisins, Zearalenone, Trichothecenes and Ergot alkaloids were deeply analyzed.

Proteomic analysis using iTRAQ technology reveals the toxic effects of zearalenone on the leydig cells of rats

Zearalenone (ZEA) is a mycotoxin that contaminates crops worldwide and is toxic to the reproductive systems of mammals, however, the toxicological mechanism by which ZEA affects germ cells is not fully understood. In this study, proteomic analysis using iTRAQ technology was adopted to determine the cellular response of Leydig cells of rats to ZEA exposure. The results were used to elucidate the mechanisms responsible for the toxicity of the ZEA towards germ cells. After 24 h of exposure to ZEA at a concentration of 30 μmol/L, a total of 128 differentially expressed proteins (DEPs) were identified. Of these, 70 DEPs were up-regulated and 58 DEPs were down-regulated. The DEPs associated with ZEA toxicology were then screened by using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The results show that these DEPs are involved in a number of important ZEA toxicological pathways including apoptosis, immunotoxicity, DNA damage, and signaling pathways. The complex regulatory relationships between the DEPs and ZEA toxicological signaling pathways are also explicitly demonstrated in the form of a protein-protein interaction network. This study thus provides a theoretical molecular basis for understanding the toxicological mechanisms by which ZEA affects germ cells.

Zearalenone nephrotoxicity: DNA fragmentation, apoptotic gene expression and oxidative stress protected by Lactobacillus plantarum MON03

The present study was conducted to determine the abilities of the living Lactobacillus plantarum MON03 cells to degrade Zearalenone (ZEN) in liquid medium, and to elucidate the preventive effect in ZEN-contaminated balb/c mice showing kidney damage. The DNA fragmentation, Bcl-2 and Bax gene expression, caspase-3 activity, mRNA level of inflammation-regulating cytokines and histology of kidney tissues were examined. Female Balb/c mice were divided into four groups (10/group) and treated daily for 2 wk by oral gavage with lactic acid bacteria (L. plantarum MON03) 2 × 109 CFU/L, ~2 mg/kg only, ZEN (40 mg/kg BW) only, ZEN (40 mg/kg BW) + lactic acid bacteria (L. plantarum MON03, 2 × 109 CFU/L, ~2 mg/kg). Control group received vehicle. At the end of experiment, the kidney was collected for the determination of DNA fragmentation, Bcl-2 and Bax gene expression,caspase-3 activity, Malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) content, as well as for any alterations in expression of total antioxidant activity (TAC) and mRNA levels of inflammation-regulating cytokines (e.g., IL-10, IL-6, TNF-alpha). The results indicated that, kidney cells exposure to ZEN led to increased caspase-3 activity, MDA, and IL-10, IL-6, TNF-alpha and Bax mRNA levels, but decreased TAC content and down-regulated expression of GSH-Px and CAT and Bcl-2 mRNA. Co-treatment with ZEN plus LP suppressed the levels of DNA fragmentation; normalized kidney MDA and increased CAT levels, up-regulated expression of GSH-Px and CAT, and normalized mRNA levels of the analyzed cytokines. It's concluded that ZEN might have toxic effects in kidney. Further, it can be seen that use of LP induced protective effects against the oxidative stress and kidney toxicity of ZEN in part through adhesion (and so likely diminished bioavailability).