Preventive role of phyllosilicate clay on the Immunological and Biochemical toxicity of zearalenone in Balb/c mice

Effect of the bread-making process on zearalenone levels

The effects of the bread-making process including fermentation with Saccharomyces cerevisiae and lactic acid bacteria (Lactobacillus casei, Lactobacillus rhamnosus, Lactobacillus acidophilus and Lactobacillus fermentum) and baking at 200°C on zearalenone (ZEA) levels were investigated. Standard solutions of ZEA were added to flour and then loaves of bread were prepared. Sourdough and three types of yeast including active dry yeast, instant dry yeast and compressed yeast were used for the fermentation of dough. ZEA levels in flour, dough and bread were determined by HPLC with fluorescence detection after extraction and clean-up on an immunoaffinity column. The highest reduction in levels of ZEA was found in the first fermentation (first proof), while the lowest reduction was observed in the baking stage. In addition, the results showed that compressed yeast had the maximum reduction potential on ZEA levels even at the baking stage.

Biological detoxification of zearalenone by Aspergillus niger strain FS10

Zearalenone (ZEN) contamination of corn and cereal products is a serious health hazard throughout the world and its elimination by microbial methods is now being widely examined. In this study, an Aspergillus niger strain, FS10, isolated from Chinese fermented soybean, was shown to reduce levels of ZEN in corn steep liquor (CSL). Spores, mycelium and culture filtrate of the strain FS10 were tested for their ability to remove ZEN. The results indicated that strain FS10 could remove 89.56% of ZEN from potato dextrose broth (PDB) medium. Mycelium and culture filtrate decreased the ZEN content by 43.10% and 68.16%, respectively. The contaminated corn steep liquor initially contained ZEN 29 μg/ml, 60.01% of which could be removed by strain FS10. To demonstrate the loss of toxicity in vivo, the culture filtrate incubated with the contaminated corn steep liquor for 48 h was administered to rats. The results indicated that the contaminated corn steep liquor severely damaged liver and kidney tissue. Rats administered with contaminated corn steep liquor treated with the strain FS10 culture filtrate showed significantly less severe liver and kidney damage, and organ index values were comparable to the non-ZEN-exposed control (p<0.05). Our study suggests an effective approach to reduce the hazards of ZEN in corn steep liquor.

The immunomodulatory effects induced by dietary Zearalenone in pregnant rats

CONTEXT

Zearalenone (ZEN) is a common contaminant that is present in feedstuff of high humidity and high temperatures.

OBJECTIVE

The aim of this study was to investigate the effects of diets contaminated with different concentrations of ZEN on immunomodulation in early pregnant rats.

MATERIALS AND METHODS

Forty-eight pregnant Sprague Dawley (SD) rats were randomly divided into four treatment groups fed on a diet supplemented with one of four concentrations of ZEN: 0 mg/kg (ZEN 0), 50 mg/kg (ZEN 50), 100 mg/kg (ZEN 100) and 150 mg/kg (ZEN 150). The pregnant rats were fed ZEN-treated diets from gestation days 0 to 7 and a basal diet from gestation days 8 to 20.

RESULTS

ZEN exposure (ZEN 100 and 150) caused significant decreases in splenic coefficients, viability of splenocyte and T-cell proliferation and induced histopathological damage in the spleen of early pregnant rats compared with other groups. Levels of IgG and IgA were decreased, while IgM was increased, in high doses of ZEN (ZEN 100 and ZEN 150) compared with other groups. ZEN 150 caused increases in white blood cells and hemoglobin and induced a significant decrease in platelets in blood of the pregnant rats compared with other groups. ZEN 150 increased the mRNA expression levels of interleukin (IL)-6, IL-18 and IL-1β and decreased the mRNA expression levels of interferon-γ, tumor necrosis factor-α and IL-10 in the spleen of pregnant rats compared with ZEN 0.

CONCLUSION

High doses of ZEN-induced immunomodulatory effects on early pregnant rats by altering immunological parameters.

Biochemical changes and oxidative stress induced by zearalenone in the liver of pregnant rats

The aim of the present research was to examine the toxic influence of different doses of zearalenone (ZEN) on the liver, especially oxidative stress induced by ZEN on the liver. A total of 48 pregnant Sprague-Dawley rats were randomly assigned into 4 treatments groups with 12 animals in each. The rats were fed with a normal diet treated with 0 mg/kg (control), 50 mg/kg (treatment 1), 100 mg/kg (treatment 2), or 150 mg/kg (treatment 3) ZEN in feed on gestation days (GDs) 0–7 and then all the rats were fed with a normal diet on GDs 8–20. The experimental period lasted 21 days. The results showed that exposure to ZEN induced increase in aspartate amino transferase, alanine aminotransferase, and alkaline phosphatase activities and decrease in total protein and albumin content in a dose-dependent manner and also induce decrease in superoxide dismutase and glutathione peroxidase activities and increase in malondialdehyde content in a dose-dependent manner in the serum and the liver. The increased transcription of cytochrome P450 2E1 (CYP2E1) was detected in the liver after exposure to ZEN. These results suggested that ZEN not only caused damage in the liver of pregnant rats in a dose-dependent manner but also induced the messenger RNA expression of CYP2E1 in the liver.

Toxic effects of zearalenone on oxidative stress, inflammatory cytokines, biochemical and pathological changes induced by this toxin in the kidney of pregnant rats

An experiment was conducted to determine the toxic effects of zearalenone (ZEN) on oxidative stress, inflammatory cytokines, biochemical and pathological changes in the kidney of pregnant rats, and to explore the possible mechanism in ZEN induced kidney damage. The rats were fed a normal diet treated with 0.3, 48.5, 97.6 or 146 mg/kg ZEN in feed on gestation days (GDs) 0 through 7, and then all the rats were fed with a normal diet on GDs 8 through 20. The results showed that ZEN induced kidney dysfunction, oxidative damage, pathological changes and increased mRNA and protein expression of TLR4 and inflammatory cytokines in kidney in dose-dependent manner. The results indicated that ZEN caused kidney damage of pregnant rats and TLR4-mediated inflammatory reactions signal pathway was one of the mechanisms of ZEN mediated toxicity in kidney.

Fusarial toxins: secondary metabolites of Fusarium fungi

Exposure to mycotoxins occurs worldwide, even though there are geographic and climatic differences in the amounts produced and occurrence of these substances.Mycotoxins are secondary chemical metabolites of different fungi. They are natural contaminants of cereals, so their presence is often inevitable. Among many genera that produce mycotoxins, Fusarium fungi are the most widespread in cereal-growing areas of the planet. Fusarium fungi produce a diversity of mycotoxin types, whose distributions are also diverse. What is produced and where it is produced is influenced primarily by environmental conditions, and crop production and storage methods. The amount of toxin produced depends on physical (viz., moisture, relative humidity, temperature, and mechanical damage), chemical (viz., carbon dioxide,oxygen, composition of substrate, insecticides and fungicides), and biological factors (viz., plant variety, stress, insects, spore load, etc.). Moisture and temperature have a major influence on mold growth rate and mycotoxin production.Among the most toxic and prevalent fusaria) toxins are the following: zearalenone,fumonisins, moniliformin and trichothecenes (T-2/HT-2 toxin, deoxynivalenol,diacetoxyscirpenol, nivalenol). Zearalenone (ZEA; ZON, F-2 toxin) isaphy to estrogenic compound, primarily a field contaminant, which exhibits estrogenic activity and has been implicated in numerous mycotoxicoses of farm animals,especially pigs. Recently, evidence suggests that ZEA has potential to stimulate the growth of human breast cancer cells. Fumonisins are also cancer-promoting metabolites,of which Fumonisin 8 I (FBI) is the most important. Moniliformin (MON) isalso highly toxic to both animals and humans. Trichothecenes are classified as gastrointestinal toxins, dermatotoxins, immunotoxins, hematotoxins, and gene toxins.T-2 and HT-2 toxin, and diacetoxyscirpenol (DAS, anguidine) are the most toxic mycotoxins among the trichothecene group. Deoxynivalenol (DON, vomitoxin) and nivalenol although less toxic are important because they frequently occur at levels high enough to cause adverse effects.The presence of mycotoxins in the animal diet can produce significant production losses. Any considerable presence of mycotoxins, in major dietary components,confirms the need to adopt a continuous prevention and control program. Such programs are usually based on several common approaches to minimize mycotoxin contamination in the food chain. Major strategies include preventing fungal growth and therefore mycotoxin formation, reducing or eliminating mycotoxins from contaminated feedstuffs, or diverting contaminated products to low risk uses. Because of the complexity of their chemical structures, mycotoxins also present a major analytical challenge. They are also found in a vast array of feed matrices. Analysis is essential for determining the extent of mycotoxin contamination, for risk analysis, confirming the diagnosis of a mycotoxicosis and for monitoring mycotoxin mitigation strategies.For the future, adequately controlling the mycotoxin problem in the livestock economy will depend on implementing appropriate agricultural management policies,as well as augmenting production and storage systems and analysis methods.Only such policies offer the opportunity to bring solid and long-lasting economical results to the livestock industry that is afflicted with the mycotoxin problem.

Zearalenone affects immune-related parameters in lymphoid organs and serum of rats vaccinated with porcine parvovirus vaccine

Rats were administered zearalenone (ZEA) via gavage at dosages of 0, 1, 5, and 30 mg/kg for 36 days. On treatment day 8, inactivated porcine parvovirus vaccine (Vac) was injected intraperitoneally. Antibody production against porcine parvovirus was then measured as a function of ZEA treatment. Compared to the vaccine alone, ZEA treatment, with or without Vac, decreased the serum level of IgG. The level of IgM decreased in all ZEA groups at day 22, but the decrease was sustained only in the medium-dose ZEA group at day 36. The level of IgA was unchanged in the Vac only and ZEA groups at day 22, but was decreased in the 5 mg/kg ZEA plus Vac group compared to the Vac only group at day 36. The level of IgE was decreased by all doses of ZEA at day 22, but was unaffected in ZEA plus Vac groups compared to the Vac only group. The levels of IL-1 in the thymus and spleen; INF-γ in serum; IL-2, IL-6, and IL-10 in the thymus; and IL-10 and IFN-γ in the spleen decreased after ZEA administration. Furthermore, the levels of IL-1β in the spleen and mesenteric lymph node, IL-1β in the thymus, IL-2 in the thymus and spleen, IL-6 in the thymus, IL-10 and IFN-γ in the spleen, and GM-CSF and TNF-α in the thymus decreased after vaccination in rats exposed to ZEA. In conclusion, these results suggest that ZEA exposure via drinking water can cause an immunosuppressive effect by decreasing immunoglobulins in serum and cytokines in lymphoid organs.

Evaluation of Oxidative DNA Damage Using an Alkaline Single Cell Gel Electrophoresis (SCGE) Comet Assay, and the Protective Effects of N-Acetylcysteine Amide on Zearalenone-induced Cytotoxicity in Chang Liver Cells

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 μM) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 μM). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

Biological system responses to zearalenone mycotoxin exposure by integrated metabolomic studies

This study aims to investigate the effect of zearalenone supplementation on rat metabolism. Rats received biweekly intragastric administration of zearalenone mycotoxin (3 mg/kg body weight) for 2 weeks. Urine and plasma samples after zearalenone administration were analyzed by NMR-based metabolomics. Zearalenone exposure significantly elevated the plasma levels of glucose, lactate, N-acetyl glycoprotein, O-acetyl glycoprotein, and propionate but reduced the plasma levels of tyrosine, branched-chain amino acids, and choline metabolites. Zearalenone supplementation decreased the urine levels of butyrate, lactate, and nicotinate. However, it increased the urine levels of allantoin, choline, and N-methylnicotinamide at 0-8 h after the last zearalenone administration and those of 1-methylhistidine, acetoacetate, acetone, and indoxyl sulfate at 8-24 h after the last zearalenone administration. These results suggest that zearalenone exposure can cause oxidative stress and change common systemic metabolic processes, including cell membrane metabolism, protein biosynthesis, glycolysis, and gut microbiota metabolism.

Effects of red ginseng extract on zearalenone induced spermatogenesis impairment in rat

Zearalenone (ZEA) is a phenolic resorcylic acid lactone compound produced by several species of Fusarium. ZEA has toxic effects in the testes of domestic and laboratory animals. Korean red ginseng (KRG), the steamed root of Panax ginseng Meyer, has multiple pharmacological effects such as vasorelaxation, anti-thrombosis, anti-hypertension, etc. In this study, we investigated the effects of KRG extract on testicular toxicity induced by ZEA. Rats were treated with 300 mg/kg oral doses of KRG for 4 weeks every other day. The rats were then treated with a single dose of 5 mg/kg ZEA delivered intraperitoneally, whereas control rats received only doses of the vehicle. As a result, germ cell apoptosis induced by ZEA was decreased by KRG pre-treatment. In addition, Fas and Fas-L expression was reduced in rats that received KRG pre-treatment compared to ones treated with ZEA alone. In conclusion, impaired spermatogenesis resulting from ZEA treatment was prevented by KRG through Fas-Fas L modulating.

Mycotoxin-containing diet causes oxidative stress in the mouse

Mycotoxins which mainly consist of Aflatoxin (AF), Zearalenone (ZEN) and Deoxynivalenol (DON) are commonly found in many food commodities. Although each component has been shown to cause liver toxicity and oxidative stress in several species, there is no evidence regarding the effect of naturally contained multiple mycotoxins on tissue toxicity and oxidative stress in vivo. In the present study, mycotoxins-contaminated maize (AF 597 µg/kg, ZEN 729 µg/kg, DON 3.1 mg/kg maize) was incorporated into the diet at three different doses (0, 5 and 20%) to feed the mice, and blood and tissue samples were collected to examine the oxidative stress related indexes. The results showed that the indexes of liver, kidney and spleen were all increased and the liver and kidney morphologies changed in the mycotoxin-treated mice. Also, the treatment resulted in the elevated glutathione peroxidase (GPx) activity and malondialdehyde (MDA) level in the serum and liver, indicating the presence of the oxidative stress. Moreover, the decrease of catalase (CAT) activity in the serum, liver and kidney as well as superoxide dismutase (SOD) activity in the liver and kidney tissue further confirmed the occurrence of oxidative stress. In conclusion, our data indicate that the naturally contained mycotoxins are toxic in vivo and able to induce the oxidant stress in the mouse.

Organically modified clays as binders of fumonisins in feedstocks

This study reports an investigation on the ability of organically modified clays to bind mycotoxins, fumonisins B1 (FB1) and B2 (FB2). Organically modified clays are commercia materials prepared from natural clays, generally montmorillonite, by exchanging the inorganic cation with an ammonium organic cation. A screening experiment conducted on 13 organically modified clays and 3 nonmodified clays, used as controls, has confirmed that the presence of an organic cation in the clay interlayer promoted the adsorption of both fumonisins. On the basis of the results of the screening test, four modified clays and a Na-montmorillonite were selected for the determination of the adsorption kinetics and isotherms. On all the tested materials adsorption took place within one hour of contact with fumonisins solutions. Adsorption isotherms have pointed out that the modified clays exhibited a higher adsorptive capacity than the unmodified clay. It was also demonstrated that, notwithstanding the reduced structural difference between FB1 and FB2, they were differently adsorbed on the modified clays. Addition of 2% modified clays to contaminated maize allowed a reduction of more than 70% and 60% of the amount of FB1and FB2 released in solution. Although in vivo experiments are required to confirm the effectiveness of the organically modified clays, these preliminary results suggest that these materials are promising as fumonisins binders.

Interaction of Lactobacillus plantarum MON03 with Tunisian montmorillonite clay and ability of the composite to immobilize Zearalenone in vitro and counteract immunotoxicity in vivo

BACKGROUND AND AIM

The present study was conducted to determine the abilities of the living Lactobacillus plantarum MON03 (LP) cells, Tunisian montmorillonite clay and their composites to accumulate Zearalenone (ZEA) from a liquid medium and elucidate the preventive effect of their composite in ZEA-contaminated balb/c mice showing immunotoxicity disorders.

MATERIALS AND METHODS

In the in vitro study, LP (2 × 10(9) CFU/mL), TM (0.5 mg) and LP+TM were incubated with 50 µg mL(-1) ZEA for 0, 12 and 24 h. For the in vivo study, the composite MT+LP was evaluated also for possible protection regarding ZEA-immunotoxicity in Balb/c mice as a sensitive model.

RESULTS

Results indicated that TM and LP+TM had a high capacity of adsorbing ZEA 87.2 ± 2.1 and 94.2 ± 2.1%, respectively. However, LP alone able to remove only 78% after 24 h of incubation. The quantity of adsorbed ZEA by LP, TM and LP+TM were 39, 43,5 and 47 µg mL(-1) of PBS, respectively. The in vivo results indicated that mice orally exposed to ZEA- (40 mg/kg bw) for 2 weeks showed severe immunotoxicity typical of fusarotoxicosis regarding thymocytes and splenocytes cell viability count, IFN-γ, IL-12, TNF-α production and B-cell activation. Mice treated with LP and TM alone, and LP+MT in combination with ZEA were comparable to the control.

CONCLUSION

Both LP and TM are safe by themselves and their composite succeeded to exert a potential prevention by counteracting ZEA-immunotoxicity and can be implicated in the biotechnology of ZEA removal in human food and animal feed.

Effects of zearalenone in prepubertal gilts

Prepubertal gilts were fed with a diet containing zearalenone (ZEA) in a concentration of 0.75 mg/kg for 21 days. The effects of this mycotoxin on morphologic aspects of the reproductive tract as well as on complete blood count (CBC), serum biochemistry analysis (SBA) and humoral immune response against sheep red blood cells (SRBC) were evaluated. There was a significant increase (P<0.05) on the reproductive tract weight, vulvar area, height of the epithelial cells of endometrial glands and uterine mucosa. These results showed the ability of this nonsteroidal mycotoxin in mimicking actions of 17β estradiol at the concentration of 0.75mg/kg. No changes in weight gain, CBC, SBA parameters and humoral response against SRBC were observed.

Effects of zearalenone and its derivatives on porcine immune response

Zearalenone (ZEN), a mycotoxin produced by several Fusarium spp., is most commonly found as a contaminant in stored grain and has chronic estrogenic effects on mammals. In this in vitro study, we compared the effects of zearalenone (ZEN) and some of its derivatives: α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), and zearalanone (ZAN) on several peripheral blood mononuclear cell (PBMC) parameters: cytotoxicity, proliferation, as well as antibody and cytokine synthesis. The amounts of toxins necessary to inhibit viability, in a dehydrogenase enzyme activity assay (MTT test), by 50% were: 22.7 μM for ZEN, 29.1 μM for α-ZOL, 17.3 μM for β-ZOL and 26.3 μM for ZAN. The administration of 10 μM toxin induced a decrease in the ConA stimulated proliferation of PBMC by 19.6% for ZAN, 45.4% for ZEN, 43.6% for α-ZOL and 85.2% for β-ZOL, when compared to the control stimulated cells. Also, ZEN and its metabolites at concentrations higher than 5 μM induced a significant decrease of the IgG, IgA or IgM levels. Concentrations of 5 and 10 μM of ZEN and ZAN significantly decreased the TNF-α synthesis in the supernatant of the stimulated cells; 10 μM of ZAN also decreased IL-8 synthesis. In conclusion, our results show that ZEN and ZEN derivatives altered several parameters of the humoral and cellular immune response. Therefore, our results are clinically relevant as ZEN and its metabolites are frequent contaminants of animal feed and we have shown that intoxicated animals are incapable of inducing an adequate immune response.

In-vitro free radical scavenging, antiproliferative and anti-zearalenone cytotoxic effects of 4-(methylthio)-3-butenyl isothiocyanate from Tunisian Raphanus sativus

Objectives

The aim of this study was to investigate the antiradical and antioxidant properties of 4-(methylthio)-3-butenyl isothiocyanate (MTBITC) extracted from Raphanus sativus and to assess the effects of MTBITC on tumour cell growth, cytotoxicity induced by zearalenone, an oestrogenic mycotoxin, and modulation of the expression of the genes involved in these aspects of cell behaviour.

Methods

A murine leukaemia cell line (L1210) was grown in vitro and supplemented with MTBITC (2, 4, 8, 16 and 32 μm) for 48 h. Cell growth was evaluated by the MTT assay. The chemopreventive role of MTBITC on the cytotoxic effect of zearalenone in a Balb/c mice keratinocyte cell line (C5-O) was also evaluated. Apoptosis and lipid peroxidation were assessed, as well as the expression of genes involved following zearalenone treatment alone or in combination with MTBITC.

Key findings

MTBITC showed a significant ability to inhibit nitroblue tetrazolium reduction by superoxide radicals in a non-enzymatic superoxide generating system, to scavenge free radicals and to cause a decrease in L1210 cell growth. The C5-O cells treated with zearalenone alone showed a high frequency of apoptotic cells and lipid peroxidation, typical of oxidative stress generated by zearalenone. The cotreatment with MTBITC reduced the cytotoxicity of zearalenone and the subsequent gene expression analysis demonstrated that MTBITC decreased the expression of caspase 8, implicated in the physiological mechanism to eliminate injured or abnormal cells.

Conclusions

The results suggest that MTBITC was able to inhibit L1210 cell growth and counteract the zearalenone oxidative stress to C5-O cells through caspase 8 inhibition of apoptosis.

Zearalenone induces immunotoxicity in mice: possible protective effects of radish extract (Raphanus sativus)

Radish (Raphanus sativus) has been extensively studied for its preventive effects against different degenerative diseases. Zearalenone (ZEN) is a mycotoxin produced by Fusarium spp and is frequently implicated in immunological disorders and occasionally in hyperoestrogenic syndromes contributing to the increased risk of cancer and other diseases. The aims of this study were, firstly, to quantitatively evaluate the Tunisian radish extract (TRE) for its total flavonoids, isothiocyanates and antioxidant activity and, secondly, to investigate the protective role of TRE against immune system disorders in Balb/c mice treated with ZEN for two weeks. The results indicated that mice treated with ZEN (40 mg kg−1) alone showed a significant decrease in lymphocytes of the total white blood cells, immunoglobulin profile (IgG and IgM), B cells, T-cell sub-types (CD3+, CD4+ and CD8+) and natural killer and pro-inflammatory cytokines. Mice treated with TRE (5, 10 or 15 mg kg−1) for 7 days before, during or after ZEN treatment, however, showed a significant improvement in lymphocyte, immunoglobulin profile, T-cell sub-types, B cells and pro-inflammatory cytokines. Moreover, treatment with the highest dose of TRE (15 mgkg−1) enhanced the release of tumour necrosis factor-α and interleukin-1β but the other parameters were comparable with those of the control. It could be concluded that TRE was effective in protecting against ZEN-induced immunological disorders. These results supported our hypothesis that TRE contains several compounds that are able to prevent or inhibit ZEN toxicity.

Montmorillonite adsorbs creatinine and accelerates creatinine excretion from the intestine

Objectives

This study aims to evaluate the sorption by montmorillonite of creatinine and the accelerating effect of montmorillonite on creatinine excretion from the intestine.

Methods

The sorption of montmorillonite was observed in vitro. Also, rat intestinal tract and blood vessels were perfused circularly with perfusate with or without creatinine, respectively, to study the promotion of creatinine diffusion from the blood vessel to the intestine and the inhibition of creatinine absorption in the intestinal tract. The effect of decreasing the serum concentration of creatinine was studied in an acute hypercreatininaemia mouse model. The concentration of creatinine was determined by the basic picric acid method.

Key findings

Montmorillonite adsorbed creatinine markedly in the simulated intestinal solution in a concentration-dependent manner. The sorption–time curve of montmorillonite with creatinine showed that the sorption was fast. The adsorption rate reached a maximum in 10 min. The pH of the solution influenced the sorption, the rate of which was higher at a low pH than at a high pH. Creatinine could diffuse from the blood vessel to the intestine and was reabsorbed in the intestine. Montmorillonite promoted the diffusion and inhibited the absorption. Montmorillonite decreased the serum creatinine level of hypercreatininaemia mice prepared by injecting creatinine intraperitoneally.

Conclusions

Montmorillonite adsorbs creatinine and accelerates its excretion from the intestine.

Raphanus sativus extract prevents and ameliorates zearalenone-induced peroxidative hepatic damage in Balb/c mice

Objectives

Raphanus sativus (radish) is a species of crucifer, which includes widely consumed vegetables, distributed in Asia, Africa and Europe. It is a rich source of bioactive molecules including anthocyanins, glucosinolates, isothiocyanates and other flavonoids, and miscellaneous phenolic substances. We have evaluated the hepatoprotection of R. sativus extract against zearalenone, an estrogenic mycotoxin initiating hepatotoxicity in male Balb/c mice.

Methods

Animals were divided into seven treatment groups and treated orally each day for twenty eight days as follows: a control, an olive oil group, group I, group II, and group III treated with radish extract alone (5, 10 and 15 mg/kg, respectively), group IV treated with zearalenone (40 mg/kg), and group V treated with zearalenone plus the lowest dose of radish extract.

Key findings

Administration of zearalenone alone resulted in significant decreases in the levels of alkaline phosphatase, lactate dehydrogenase, alanine and aspartate aminotransferases in the liver, suggesting hepatic damage. Moreover, a marked increase in the level of lipid peroxide and concomitant decrease of glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, glutathione-S-transferase, RNA and DNA concentrations were also observed in the liver tissue of zearalenone-treated mice. Co-treatment with R. sativus extract plus zearalenone succeeded in reversing the condition back to normal levels for all studied parameters.

Conclusions

By itself R. sativus extract did not show any toxic effects and could be considered as a potent hepatoprotectant.

Raphanus sativus extract protects against Zearalenone induced reproductive toxicity, oxidative stress and mutagenic alterations in male Balb/c mice

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium in cereals and agricultural products. It has been implicated in several mycotoxicosis in farm animals and in humans. There is unequivocal evidence of reproductive toxicity of ZEN in male mice although the mechanism of action is unknown. Several reports suggest that exposure to ZEN resulted in oxidative stress, genotoxicity and perturbation of reproductive parameters. Therefore, the aim of the current study was to evaluate the protective effects of aqueous extract of Raphanus sativus growing in Tunisia against ZEN-induced reproductive toxicity and oxidative stress. Fifty male Balb/c mice were divided into five groups and treated for 28 days as follows: the control group, olive oil-treated groups, another treated with ZEN (40 mg/kg b.w), the last one treated with R. sativus extract alone (15 mg/kg b.w) and the other with ZEN + R. sativus extract. Testis samples were collected for the epididymal sperm count, testosterone concentration, and MDA level, GPx, CAT and SOD activities. Blood samples were collected for different biochemical analyses. Also, RAPD-PCR method was performed to assess the antigenotoxic effect of the extract in germ cells. The results indicated that ZEN-induced toxicological effects in accordance to those reported in the literature: decreasing in the sperm number, testosterone level and antioxidant enzyme status. The RAPD-PCR analysis revealed an alteration in the DNA bands patterns between control and ZEN-treated mice. The extract alone, rich in many antioxidant compounds, was safe and succeeded in counteracting the oxidative stress and protect against the toxicity resulting from ZEN.

Dietary glucomannan improves the vaccinal response in pigs exposed to aflatoxin B1 or T-2 toxin

The aim of the study was to investigate whether dietary supplementation with yeast-derived glucomannan protects pigs against the deleterious effects that exposure to aflatoxin B1 (AFB1) or T-2 toxin has on the vaccinal immune response and drug-metabolising enzymes. Three doses of pure mycotoxin (AFB1 trial: 482, 968 and 1,912 µg/kg feed; T-2 toxin trial: 593, 1,155 and 2,067 µg/kg feed) with or without dietary glucomannan supplementation (2 g/ kg feed) were tested in weaned pigs for 28 days. At days 4 and 15 pigs were immunised with ovalbumin to study the humoral and cell-mediated antigen-specific immune responses. The effects of AFB1 and T-2 toxin intake alone in pigs have already been published. In all parameters investigated no differences were apparent between animals receiving the unsupplemented control diet or the control diet containing glucomannan. In the AFB1 trial glucomannan decreased the severity of liver lesions in animals exposed to 968 µg/kg feed. Exposure to both AFB1 and T-2 toxin were associated with impaired phase I liver enzyme activities, but glucomannan demonstrated a limited protective effect on these enzymes. With regard to the immune defence system, both toxins modulated the vaccinal immune response; AFB1 impaired specific cellular response and T-2 toxin the specific humoral response. Glucomannan supplementation restored the ovalbumin-specific lymphocyte proliferation that was delayed in pigs exposed to AFB1, regardless of dose. In the T-2 toxin trial glucomannan supplementation restored anti-ovalbumin immunoglobulin G production, which was significantly reduced in pigs exposed to both medium and high doses of the toxin. In conclusion, glucomannan dietary supplementation demonstrated no deleterious effects in control animals and protective effects against AFB1 and T-2 toxin immunotoxicity during a vaccinal protocol.

The antigenotoxic activities of cactus (Opuntia ficus-indica) cladodes against the mycotoxin zearalenone in Balb/c mice: prevention of micronuclei, chromosome aberrations and DNA fragmentation

Zearalenone (ZEN) is a potent estrogenic metabolite. Evidence of its cytotoxicity and genotoxicity has recently emerged from several reports. This study was conducted to evaluate the ability of cactus (Opuntia ficus-indica) cladodes to protect Balb/c mice against ZEN induced genotoxicity. To this end, the effect of a single dose of ZEN (40 mg/kg b.w.) alone and with extract of cactus cladodes (25, 50 and 100 mg/kg b.w.) was monitored by measuring: (i) micronuclei induction in bone marrow cells, (ii) chromosome aberrations mainly breaks and gaps in bone marrow cells also and finally and (iii) DNA fragmentation in liver and kidney. Our results clearly show that ZEN is genotoxic to Balb/c mice. It induces DNA damage as indicated by DNA fragmentation, micronuclei and chromosomal aberrations in bone marrow cells. It is of note that cactus cladodes extract assayed alone at high dose (100 mg/kg b.w.) was found completely safe and did not induce any genotoxic effects. The simultaneous administration of cactus cladodes extract with ZEN resulted in an efficient prevention of micronuclei (the number of PCE MN decreased from 71.3+/-6.1 for animals treated with Zen to 32.6+/-15.5 for animals treated with cactus cladodes), chromosomal aberrations frequency (the % of chromosomal aberrations decreased from 38.3+/-3.0 to 18.6+/-1.1) in bone marrow cells and of DNA fragmentation compared to the group treated with ZEN alone. It could be concluded that cactus cladodes extract was effective in the protection against ZEN genotoxicity. This could be relevant, particularly with the emergent demand for natural products which may neutralize the genotoxic effects of the multiple food contaminants.

The mycotoxin Zearalenone induces apoptosis in human hepatocytes (HepG2) via p53-dependent mitochondrial signaling pathway

Zearalenone (Zen) is a fusarial mycotoxin commonly found in several food commodities worldwide. It is frequently implicated in reproductive disorders and exerts several genotoxic effects in vivo and in vitro. In response to DNA damage, cells may undergo an intricate network of different pathways including apoptosis. Meanwhile, data regarding the induction of apoptosis after Zen exposure are limited. Thus, the aim of this study was to demonstrate whether Zen-induced DNA damage can lead to apoptosis as a stress response and which pathways are undertaken. Our results clearly show that Zen reduces cell proliferation in HepG2 cells in a dose-dependent manner as attested by the MTT assay (IC50%, 100microM). The analysis of propidum iodide uptake has shown that the amount of necrotic cells was about 6% among 55% of dead cells (at 120microM of Zen). The involvement of apoptosis as a major cause of Zen-induced cell death was further confirmed but results of caspase-3 activity showed a Zen-dose dependant increase. Furthermore, results of microarrays analysis have shown that Zen induced an upregulation of ATM and p53 genes family. ATM pathway responds primarily to DNA double-strand breaks and has been involved in the activation and stabilization of p53. The activation of p53 was accompanied by an upregulation of GADD45 to arrest the cell cycle and to allow the repair mechanisms to take place. In addition, results of genes profiling as well as western-blotting analysis showed that Zen increased the ratio of pro-apoptotic factors/anti-apoptotic factors which led to the loss of mitochondrial potential, Bax translocation and cytochrome c release. Once released, cytochome c activates caspase 9 which in turn activates caspase-3 and enhances apoptosis. In summary, these data suggested that Zen induced apoptosis in a dose-dependent manner in HepG2 cells via a p53-dependent mitochondrial pathway.

Inactivation of cadmium induced immunotoxicological alterations in rats by Tunisian montmorillonite clay

Cadmium (Cd(2+)) is a heavy metal that is dispersed throughout the modern environment mainly as a result of pollution from a variety of sources. The aims of the current study were to investigate the efficacy of purified Tunisian montmorillonite clay (TMC) to adsorb Cd, to test the stability of the resulting complex under different conditions in vitro, and to utilize the rat bioassay as an in vivo model to evaluate the protective role of TMC against Cd-induced toxicity and immunodysfunction. In the in vitro study, three concentrations of TMC (0.5, 1.0 and 1.5 g/l aqueous solution) and three concentrations of CdCl(2) (25, 50 and 100 ppm) were tested. The results of the in vitro study showed that TMC had a high capacity of adsorbing Cd at different concentrations tested. The adsorption ranged from 95.7-100% of the available CdCl(2) in aqueous solutions. The complex TMC-Cd was stable at different pHs at 37 degrees C. The in vivo results indicated that treatment with CdCl(2) (2.5 mg/kg BW) for 2 weeks resulted in a significant decrease in triglycerides, total protein, creatinine, creatine kinase, immunoglobulin profile (Ig A and Ig G) and T-cell sub-types (CD3(+), CD4(+), CD8(+) and CD56(+)). Whereas, it significantly increase serum level of AST, ALT, LDH and induced degenerative changes in pro-inflammatory cytokines (TNF-alpha and IL-1). Rats treated with TMC alone (400, 600 and 800 mg/kg BW) were comparable to the control regarding all the tested parameters. The combined treatment of CdCl(2) and TMC at the lowest dose (400 mg/kg BW) showed a significant improvement of all tested parameters. It could be concluded that TMC was effective to protect against Cd hazards at a dose as low as 400 mg/kg BW. These results supported our hypothesis that TMC tightly-bind and immobilized Cd resulted in reduction of metal bioavailability in the gastrointestinal tract.

Tunisian radish extract (Raphanus sativus) enhances the antioxidant status and protects against oxidative stress induced by zearalenone in Balb/c mice

Radish (Raphanus sativus) is a food plant known worldwide. From antiquity it has been used in folk medicine as a natural drug against many toxicants. Zearalenone (zen) is a non-steroidal estrogenic mycotoxin present in corn and food mixture for farm animals and it is hepatotoxic, hematotoxic, immunotoxic, nephrotoxic and genotoxic. The objectives of the present study were to assess the biological activity of radish extract and to evaluate the protective role of radish extract against the toxicity of zen in female Balb/c mice. Animals were divided into seven groups and treated orally for 10 days as follows: a control, an olive oil group, groups treated with radish extract alone (5, 10 and 15 mg kg(-1) b.w.), a group treated with zen (40 mg kg(-1) b.w.) and a group treated with zen plus the lowest dose of radish extract. The results indicate that radish extract improved the antioxidant status and had no significant effects on hematological and biochemical parameters tested or histology of the liver and kidney. Treatment with zen results in a significant increase in ALT, AST, ALP, BILT, BILD, CRE accompanied with significant changes in most of hematological parameters and the antioxidant enzyme activities, co-treatment of zen and the radish extract results in a significant reestablishment of hematological, serum biochemical parameters, and the histology of the liver and kidney. These findings suggest that radish extract is safe and can be overcome or, at least, significantly diminish zen effects.