Creatine kinase and ATPase activities in piglets fed a fungal mycotoxin co-contaminated diet: Consequences in the pathogenesis of subclinical intoxication.

Creatine kinase (CK) activity, through the creatine-kinase-phosphocreatine (CK/PCr) system, provides a temporal and spatial energy buffer to maintain cellular energetic homeostasis, being responsible to provide adenosine triphosphate (ATP) to the proper function of ATPases enzymes, such as the sodium-potassium (Na+, K+-ATPase) and hydrogen (H+-ATPase) pumps. Thus, the aim of this study was to evaluate the involvement of CK/PCr system in the impairment of energetic homeostasis in piglets fed with a diet co-contaminated with mycotoxins, as well as the effects on ATPases enzymes. Animals were randomly divided in two groups (eight repetitions with two animals each): CON (basal diet) and MYC (mycotoxin diet; 9300 µg/kg of aflatoxins and 8000 µg/kg of fumonisins) which were feed during 15 days. Piglets that received a diet containing 300 µg/kg of aflatoxins and 8000 µg/kg of fumonisins (MYC group) presented lower body weight on days 10 and 15 of experiment when compared to control (CON group). Serum CK activity was lower on days 5, 10 and 15 of experiment in the MYC group. The same occurred for serum Na+, K+-ATPase and H+-ATPase activities on days 10 and 15 when compared to CON group. Moreover, serum calcium levels were superior on day 15 of experiment in the MYC group, while serum potassium and sodium levels were lower in comparison to CON group. Based on these evidences, a diet co-contaminated by aflatoxins and fumonisins inhibits serum CK activity, impairing the energetic homeostasis. This inhibition alters the activities of ATPases (Na+, K+-ATPase and H+-ATPase), contributing to the imbalance of Na+, K+ and Ca+ ionic levels. In summary, the cascade of alterations contributes directly to disease pathogenesis of piglets intoxicated by mycotoxins.

Preliminary results on the interactive effects of deoxynivalenol, zearalenone and fumonisin B1 on porcine lymphocytes.

Fusarium mycotoxins, such as fumonisin B1 (FB1), deoxynivalenol (DON) and zearalenone (ZEN), frequently co-occur in feed raw materials and their presence is ubiquitous. The aims of this study were to determine the concentration that inhibits cell viability by 50% (IC50 values) for each mycotoxin (after 24, 48 and 72 h) and to investigate their combined effects in binary (DON + ZEN: DZ, DON + FB1: DF, FB1 + ZEN: FZ) and ternary (DFZ) mixtures using cyto- and genotoxicity on porcine lymphocytes as endpoints. The potency of cytotoxicity of the three toxins in an increasing order was FB1 < ZEN < DON. The range of IC values depending on the period of exposure was 0.31-0.42 µg/ml and 16.6- 22.9 µg/ml for DON and ZEN, respectively, and 101.15 µg/ml for FB1 (50% viability was reached only after 72 h). The main interaction observed was antagonism regarding cytotoxicity. Lower and higher sets of concentrations were used for the genotoxicity (comet assay) experiments. When lower concentrations were used, antagonism was again the main interaction observed. However, at higher concentrations an antagonism was confirmed only for DFZ, whereas for DZ and FZ a synergism was observed. Interactions of DF were inconsistent in different exposure periods in both series of experiments. Further studies with additional endpoints should be performed (e.g. DNA fragmentation, protein synthesis) in order to elucidate the mechanisms underlying the interactions observed.

Risk of dietary exposure to aflatoxins and fumonisins in infants less than 6 months of age in Rombo, Northern Tanzania.

Infants less than 6 months of age receiving foods other than breast milk are at a high risk of exposure to mycotoxins. We surveyed food intake and estimated the risk of exposures to aflatoxin and fumonisin mycotoxins for infants less than 6 months of age in Northern Tanzania. A total of 143 infants were progressively recruited and three follow-up visits were made at 1, 3 and 5 months of age. A 24-h dietary recall technique was used to estimate flour intake of infants who had been introduced to maize foods. Aflatoxins and fumonisins in the flours were analysed using high-performance liquid chromatography technique. Exposure to aflatoxins or fumonisins was estimated using the deterministic approach. By the age of 3 months, 98 infants had started taking food; 67 of them, maize flours at levels ranging from 0.57 to 37.50 g per infant per day (average 8 g per infant per day). Fifty-eight per cent of 67 maize flour samples contained detectable aflatoxins (range 0.33-69.47 µg kg(-1) ; median 6 µg kg(-1) ) and 31% contained detectable fumonisins (range 48-1224 µg kg(-1) ; median 124 µg kg(-1) ). For infants who consumed contaminated flours, aflatoxin exposure ranged from 0.14 to 120 ng kg(-1) body weight (BW) per day (all above the health concern level of 0.017 ng kg(-1) BW per day as recommended by the European Food Safety Agency) and fumonisin exposure ranged from 0.005 to 0.88 µg kg(-1) BW per day. Insignificant association was observed between exposure to fumonisins or aflatoxins and stunting or underweight. Reducing aflatoxin and fumonisin contamination of maize and dietary diversification can prevent infants and the public, in general, from exposure to the toxins.

Protective role of probiotic lactic acid bacteria against dietary fumonisin B1-induced toxicity and DNA-fragmentation in sprague-dawley rats.

The genus Fusarium, especially F. verticillioides and F. proliferatum, has been found in several agricultural products worldwide, especially in maize. Regardless the occurrence of symptoms, the presence of Fusarium in maize constitutes an imminent risk due to its ability to produce fumonisins, mycotoxins with proven carcinogenic effect on rats, swine, and equines and already classified as possible carcinogens to humans. The toxicity of incremental levels of fumonisin B1 (FB1), that is, 50, 100, and 200 mg FB1/kg diet, and the role of Lactobacillus delbrueckii subsp. lactis DSM 20076 (LL) and Pediococcus acidilactici NNRL B-5627 (PA) supplementation in counteracting the FB1 effects in intoxicated rats were monitored over a period of 4 weeks. Effects on the feed intake and body weight gain were noticed. A significant (p ≤ 0.05) increase in the level of liver and kidney functions markers and DNA fragmentation was also noticed in rat groups T100 and T200. The lactic acid bacteria (LAB) supplementation could bring back the normal serum biochemical parameters in rats fed on fumonisin B1-contaminated diets (T50 and T100) compared to FB1-treated groups. In rats of high-dosage dietary groups supplemented with LAB (T200-LL and T200-PA), the supplementation reduced the serum activity levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and creatinine by 11.3, 11.9, 32, and 20%, respectively. DNA fragmentations were observed in the rat group treated with 200 mg FB1 after 3 weeks, while fragmentation was noticed in treated groups with 100 and 200 mg FB1 after 4 weeks. No DNA fragmentation was apparent in FB1-treated rats co-administered the LL or PA strain. These results suggest that in male rats consuming diets containing FB1, there is a time- and dose-dependent increase in serum enzyme activities and DNA lesions. Moreover, Lb. delbrueckii subsp. lactis (LL) and P. acidilactici (PA) strains have a protective effect against antigenotoxicity and precancerous lesions.

Lipid metabolism of commercial layers fed diets containing aflatoxin, fumonisin, and a binder.

Aflatoxins (AF) and fumonisins (FU) are a major problem faced by poultry farmers, leading to huge economic losses. This experiment was conducted to determine the effects of AF (1 mg/kg of feed) and FU (25 mg/kg of feed), singly or in combination, on the lipid metabolism in commercial layers and investigate the efficacy of a commercial binder (2 kg/t of feed) on reducing the toxic effects of these mycotoxins. A total of 168 Hisex Brown layer hens, 37 wk of age, were randomized into a 3 × 2 + 1 factorial arrangement (3 diets with no binder containing AF, FU, and AF+FU; 3 diets with binder containing AF, FU, and AF+FU; and a control diet with no mycotoxins and binders), totaling 7 treatments. The hens contaminated with AF showed the characteristic effects of aflatoxicosis, such as a yellow liver, resulting from the accumulation of liver fat, lower values of plasma very low-density lipoprotein and triglycerides, and higher relative weight of the kidneys and liver. Hepatotoxic and nephrotoxic effects of FU were not observed in this study. On the other hand, the FU caused a reduction in small intestine length and an increase in abdominal fat deposition. The glucan-based binder prevented some of the deleterious effects of these mycotoxins, particularly the effects of AF on hepatic lipid metabolism, kidney relative weight, and FU in the small intestine.

Comparative effects of fumonisins on sphingolipid metabolism and toxicity in ducks and turkeys.

Fumonisins (FBs) are mycotoxins that are found worldwide in maize and maize products. Their main toxic effects have been well characterized in poultry, but differences between species have been demonstrated. Ducks appeared very sensitive to toxicity, whereas turkeys are more resistant. At the same time, alterations of sphingolipid metabolism, with an increase of the concentration of the free sphinganine (Sa) in serum and liver, have been demonstrated in the two species, but the link between the toxicity of FBs and Sa accumulation remains difficult to interpret. The aim of the present work was to compare the effects of FBs (10 mg FB1 + FB2/kg body weight) on sphingolipid metabolism in ducks and turkeys. Growth, feed consumption, and serum biochemistry were also investigated to evaluate toxicity. The main results showed that FBs increased Sa concentrations in liver and serum in ducks and turkeys, but these accumulations were not directly correlated with toxicity. Sa accumulation was higher in the livers of turkeys than in ducks, whereas Sa levels were higher in the sera of ducks than in turkeys. Hepatic toxicity was more pronounced in ducks than in turkeys and accompanied a decrease of body weight and an increase of serum biochemistry in ducks but not in turkeys. So, although FBs increase Sa concentration in the livers of both species, this effect is not directly proportional to toxicity. The mechanisms of FB toxicity and/or the mechanisms of protection of ducks and turkeys to the Sa accumulation within the liver remain to be established.

Individual and combined effects of Salmonella typhimurium lipopolysaccharide and fumonisin B1 in broiler chickens.

The aim of this research was to evaluate the individual and combined effects of Salmonella typhimurium lipopolysaccharide (sLPS) and fumonisin B(1) (FB) on performance, relative weight of liver, biological parameters, and histological evaluation of several tissues from four hundred thirty-two 1-d-old male broiler chickens divided into 9 treatments according to the dose of FB (0, 100, or 200 mg/kg, from d 1 to d 28) and sLPS (0, 250, or 500 µg/application per bird, every other day, from d 15 to 27) administered. At the end of the experiment (28 d), significant effects caused by sLPS, FB, and the interaction of sLPS × FB were observed on several parameters. Histopathological evaluations showed significant lesions in liver and kidney caused by sLPS, FB, and their association. According to these results, both sLPS and FB (isolated or in association) cause significant effects on performance and biological parameters of broilers at 28 d of age.

Toxicokinetics of fumonisin B2 in ducks and turkeys.

Two extraction steps combined with HPLC with fluorescence detection were developed to determine the toxicokinetics of fumonisin B(2) (FB(2)) in ducks and turkeys. The limit of quantification of the method was 25 ng of FB(2)/mL. The mean extraction was 63%. After intravenous administration (single dose: 1 mg of FB(2)/kg of BW), plasma concentration time curves were best described by a 2-compartment open model. In ducks, elimination half-life, mean residence time, and clearance of FB(2) were 32 min, 12.9 min, and 9.3 mL/min per kilogram, respectively. In turkeys, these toxicokinetics parameters were 12.4 min, 5 min, and 8.7 mL/min per kilogram, respectively. Only a small amount of FB(2) was detected in plasma after oral dosing of 10 mg of FB(2)/kg of BW.

Strong Alterations in the Sphingolipid Profile of Chickens Fed a Dose of Fumonisins Considered Safe.

Fumonisins (FB) are mycotoxins known to exert most of their toxicity by blocking ceramide synthase, resulting in disruption of sphingolipid metabolism. Although the effects of FB on sphinganine (Sa) and sphingosine (So) are well documented in poultry, little information is available on their other effects on sphingolipids. The objective of this study was to analyze the effects of FB on the hepatic and plasma sphingolipidome in chickens. The first concern of this analysis was to clarify the effects of FB on hepatic sphingolipid levels, whose variations can lead to numerous toxic manifestations. The second was to specify the possible use of an alteration of the sphingolipidome as a biomarker of exposure to FB, in addition to the measurement of the Sa:So ratio already widely used. For this purpose, we developed an UHPLC MS/MS method that enabled the determination of 82 SL, including 10 internal standards, in chicken liver and plasma. The validated method was used to measure the effects of FB administered to chickens at a dose close to 20 mg FB1 + FB2/kg feed for 9 days. Significant alterations of sphingoid bases, ceramides, dihydroceramides, glycosylceramides, sphingomyelins and dihydrosphingomyelins were observed in the liver. In addition, significant increases in plasma sphinganine 1-phosphate, sphingosine 1-phosphate and sphingomyelins were observed in plasma. Interestingly, partial least-squares discriminant analysis of 11 SL in plasma made it possible to discriminate exposed chickens from control chickens, whereas analysis of Sa and So alone revealed no difference. In conclusion, our results show that the effects of FB in chickens are complex, and that SL profiling enables the detection of exposure to FB when Sa and So fail.

Non-cytotoxic dosage of fumonisin B1 aggravates ochratoxin A-induced nephrocytotoxicity and apoptosis via ROS-dependent JNK/MAPK signaling pathway.

Ochratoxin A (OTA) and fumonisin B1 (FB1), two of the most toxicologically important mycotoxins, often coexist in a variety of foodstuff and feed in humans and animals. Because of the low content of FB1 in foodstuff and feed, alone harmfulness of FB1 is often ignored. However, it is unknown whether the lower dosage of FB1 aggravates the toxicity of other mycotoxins. In this article, we aimed to investigate the effects of the lower dosage of FB1 on OTA-induced nephrotoxicity and apoptosis, and its underlying mechanism in porcine kidney cells (PK-15). Our current study showed that the non-cytotoxic concentration of FB1 (8 µM) could enhance OTA(5 µM)-induced nephrocytotoxicity and the expression of pro-apoptosis-associated genes in PK-15 cells. We also observed that the production of reactive oxygen species (ROS) was increased. However, the expression of pro-apoptosis-associated genes were down-regulated when the N-acetylcysteine (NAC), a ROS scavenger, was used in our experiment. Besides, we found that the combined toxins could increase the protein expression of p-JNK instead of p-p38 and p-ERK. Pretreatment with SP600125, a JNK inhibitor, could significantly block the promotion effects of FB1 on OTA-induced nephrocytotoxicity and apoptosis. The protein expression of p-JNK was also inhibited and the promotion effects of FB1 were significantly alleviated when NAC was used. In conclusion, the non-cytotoxic dosage of FB1 could aggravate the nephrocytotoxicity and apoptosis caused by OTA via ROS-dependent JNK/MAPK signaling pathway.

Toxicokinetics of Hydrolyzed Fumonisin B1 after Single Oral or Intravenous Bolus to Broiler Chickens Fed a Control or a Fumonisins-Contaminated Diet.

The toxicokinetics (TK) of hydrolyzed fumonisin B1 (HFB1) were evaluated in 16 broiler chickens after being fed either a control or a fumonisins-contaminated diet (10.8 mg fumonisin B1, 3.3 mg B2 and 1.5 mg B3/kg feed) for two weeks, followed by a single oral (PO) or intravenous (IV) dose of 1.25 mg/kg bodyweight (BW) of HFB1. Fumonisin B1 (FB1), its partially hydrolyzed metabolites pHFB1a and pHFB1b, and fully hydrolyzed metabolite HFB1, were determined in chicken plasma using a validated ultra-performance liquid chromatography-tandem mass spectrometry method. None of the broiler chicken showed clinical symptoms of fumonisins (FBs) or HFB1 toxicity during the trial, nor was an aberration in body weight observed between the animals fed the FBs-contaminated diet and those fed the control diet. HFB1 was shown to follow a two-compartmental pharmacokinetic model with first order elimination in broiler chickens after IV administration. Toxicokinetic parameters of HFB1 demonstrated a total body clearance of 16.39 L/kg·h and an intercompartmental flow of 8.34 L/kg·h. Low levels of FB1 and traces of pHFB1b were found in plasma of chickens fed the FBs-contaminated diet. Due to plasma concentrations being under the limit of quantification (LOQ) after oral administration of HFB1, no toxicokinetic modelling could be performed in broiler chickens after oral administration of HFB1. Moreover, no phase II metabolites, nor N-acyl-metabolites of HFB1 could be detected in this study.

Orally Administered Fumonisins Affect Porcine Red Cell Membrane Sodium Pump Activity and Lipid Profile Without Apparent Oxidative Damage.

Weaned piglets (n = 3 × 6) were fed 0, 15 and 30 mg/kg diet fumonisin (FB1, FB2 and FB3, i.e., FBs, a sphinganine analogue mycotoxin), from the age of 35 days for 21 days, to assess mycotoxin induced, dose-dependent changes in the red cells' membrane. Ouabain sensitive Na+/K+ ATPase activity was determined from lysed red cell membranes, membrane fatty acid (FA) profile was analysed, as well as antioxidant and lipid peroxidation endpoints. Final body weight was higher in the 30 mg/kg group (vs. control), even besides identical cumulative feed intake. After 3 weeks, there was a difference between control and the 30 mg/kg group in red cell membrane sodium pump activity; this change was dose-dependent (sig.: 0.036; R2 = 0.58). Membrane FA profile was strongly saturated with non-systematic inter-group differences; pooled data provided negative correlation with sodium pump activity (all individual membrane n6 FAs). Intracellular antioxidants (reduced glutathione and glutathione peroxidase) and lipid peroxidation indicators (conj. dienes, trienes and malondialdehyde) were non-responsive. We suppose a ceramide synthesis inhibitor (FB1) effect exerted onto the cell membrane, proven to be toxin dose-dependent and increasing sodium pump activity, with only indirect FA compositional correlations and lack of lipid peroxidation.

Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b1.

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

Organ traits and histopathology of rabbits fed varied levels of dietary fumonisin B(1).

In a 196-day feeding trial, 48 male crossbred rabbits (New Zealand × Chinchilla) were randomly assigned and fed varied dietary fumonisin levels of 0.13, 5.0, 7.5 and 10.0 mg fumonisin B(1)/kg diet constituting treatments 1 (control), 2, 3 and 4 respectively. Five animals were randomly selected, stunned and killed per treatment. Relative weight of various visceral organs examined except heart and adrenal gland were significantly (p < 0.05) influenced by the dietary treatments. Liver and spleen weights of rabbits fed 10.0 mg fumonisin per kg were significantly (p < 0.05) lower than those fed control diet and diet 2. Kidney and testes weights were significantly (p < 0.05) lower in rabbits fed control diet and increased with increase in the dietary fumonisin levels. Histological examination of the organs revealed that rabbits fed diets 2, 3 and 4 showed increased severe lesion of approximately 20%, 40% and 60%, respectively, of the total slides examined for each treatment. Forty per cent and 80% of the rabbits fed diets containing 7.5 and 10.0 mg/kg fumonisin, respectively, showed severe necrosis whereas 40%, 60% and 20% of the rabbits fed 5.0, 7.5 and 10.0 mg/kg, respectively, showed mild­moderate liver necrosis/lesions as compared with non-significant lesion observed in the controls. Testicles of rabbits fed diets 3 and 4 showed mild­moderate lesions and sertoli cell degeneration. Tunica mucosa erosion was observed and predominant in the stomach and small intestine of rabbits fed 7.5 and 10.0 mg fumonisin per kg diet. This suggested that fumonisin B(1) above 5.0 mg/kg in rabbit diet is toxic to body organs with potential to induce their hypofunction or total damage.

Fumonisin B1, B2 and B3 in Muscle and Liver of Broiler Chickens and Turkey Poults Fed with Diets Containing Fusariotoxins at the EU Maximum Tolerable Level.

Although provisional maximum tolerable daily intake and recommended guidelines have been established for fumonisins (FB) in food, few data are available concerning levels of FB in edible animal tissues. Such data are of particular interest in avian species that can tolerate relatively high levels of fumonisins in their feed. Also, even if multiple contamination of animal feed by toxins produced by Fusarium is very frequent, little is known about the consequences of multiple contamination for FB levels in tissues. The aim of this study was to analyze the concentrations of FB in the muscle and liver of chickens and turkeys fed with FB alone and with FB combined with deoxynivalenol (DON), and with zearalenone (ZEN). Experimental diets were formulated by incorporating ground cultured toxigenic Fusarium strains in corn-soybean based feeds. Control diets were free of mycotoxins, FB diets contained 20 mg FB1+FB2/kg, and FBDONZEN diets contained 20, 5, and 0.5 mg/kg of FB1+FB2, DON, and ZEN, respectively. Animals were reared in individual cages with free access to water and feed. The feed was distributed to male Ross chickens from the 1st to the 35th day of age and to male Grade Maker turkeys from the 55th to the 70th day of age. On the last day of the study, the birds were starved for eight hours, killed, and autopsied for tissues sampling. No sign of toxicity was observed. A UHPLC-MS/MS method with isotopic dilution and immunoaffinity clean-up of samples has been developed for analysis of FB in muscle (n = 8 per diet) and liver (n = 8 per diet). Only traces of FB that were below the LOQ of 0.25 µg/kg were found in most of the samples of animals fed with the control diets. Mean concentrations of FB1, FB2, and FB3 in muscle were 17.5, 3.39, and 1.26 µg/kg, respectively, in chickens, and 5.77, 1.52, and 0.54 µg/kg in turkeys, respectively. In the liver, the respective FB1, FB2, and FB3 concentrations were 44.7, 2.61, and 0.79 µg/kg in chickens, and 41.47, 4.23, and 1.41 µg/kg, in turkeys. Cumulated level of FB1+FB2+FB3 in the highly contaminated samples were above 60 and 100 µg/kg in muscle and liver, respectively. The concentrations of FB in the tissues of animals fed the FBDONZEN diet did not greatly differ from the concentrations measured in animals fed the diet containing only FB.

Fumonisin B1 induced compositional modifications of the renal and hepatic membrane lipids in rats - Dose and exposure time dependence.

Male Wistar rats were intraperitoneally dosed with fumonisin B1 (FB1; 0, 20, 50 and 100 mg kg-1 dietary dose equivalent) for 5 & 10 days to assess dose- and time-dependent effects on renal and hepatic phosphatidylcholine (PC), phosphatidylinositol (PI) and phosphatidylethanolamine (PE) fatty acid (FA) profiles. Renal PC showed increasing FA saturation (SAT) after 5 days; after 10 days polyunsaturation (PUFA) decreased markedly (Σ n3 (total n3), Σ n6, PUFA, unsaturation index (UI) and average FA chain length (ACL)), mostly with linear dose response. In the PI FAs similar changes were observed, decreasing monounsaturated FA, PUFA, UI and ACL (5 & 10 days), while the PE fraction was responsive in Σ n6 (↓) and SAT (↑), but only after 5 days (without dose response for both PI & PE). Liver PC exhibited increasing saturation (C16:0), decreasing polyunsaturation (C20:3 n6 [dihomo-γ-linolenic acid, DGLA]; C20:3 n3); the PI FA profile showed similar alterations after 5 days. PC & PI FA failed to respond in a dose-dependent manner to FB1. In PE FA profile DGLA decreased, with a decrease of the total n6 FA proportion and dose-dependent increase of n3 FAs. Results revealed expressed renal sensitivity, supporting our earlier published results in terms of oxidative stress and histopathological modifications.

Occurrence and Human-Health Impacts of Mycotoxins in Somalia.

Mycotoxins are secondary metabolites produced by various molds that contaminate many staple foods and cause a broad range of detrimental health effects in animals and humans through chronic exposure or acute toxicity. As such, the worldwide contamination of food and feed with mycotoxins is a significant problem, especially in sub-Saharan Africa. In this study, mycotoxin occurrence in staple foods consumed in Somalia was determined. A total of 140 samples (42 maize, 40 sorghum, and 58 wheat) were collected from a number of markets in Mogadishu, Somalia, and analyzed by a UPLC-MS/MS multimycotoxin method that could detect 77 toxins. All of the maize samples tested contained eight or more mycotoxins, with aflatoxin B1 (AFB1) and fumonisin B1 (FB1) levels reaching up to 908 and 17 322 µg/kg, respectively, greatly exceeding the European Union limits and guidance values. The average probable daily intake of fumonisins (FB1 and FB2) was 16.70 µg per kilogram of body weight (kg bw) per day, representing 835% of the recommended provisional maximum tolerable daily intake value of 2 µg/(kg bw)/day. A risk characterization revealed a mean national margin of exposure of 0.62 for AFB1 with an associated risk of developing primary liver cancer estimated at 75 cancers per year per 100 000 people for white-maize consumption alone. The results clearly indicate that aflatoxin and fumonisin exposure is a major public-health concern and that risk-management actions require prioritization in Somalia.

Determination of Fumonisin B1 in animal tissues with immunoaffinity purification.

Immunoaffinity extraction combined with high-performance liquid chromatography (HPLC) with fluorescence detection was developed to determine Fumonisin B1 (FB1) in duck tissues. The method was linear over a concentration range of 0.013-0.250 microg of FB1/g of liver, kidney and muscle. The limit of quantification was 0.013 microg FB1/g in tissue. The mean percentage of extraction was 75% for liver and kidney and 53% for muscle. This method can be used in duck for the detection of FB1 contamination after exposure, the liver being the most contaminated tissue.

Testicular and epididymal sperm reserves and sperm production of pubertal boars fed dietary fumonisin B(1).

Twenty-four male Large White weaning pigs of 8-9 weeks of age averaging 6.94+/-0.26 kg were used to evaluate the effect of dietary fumonisin B(1) (FB(1)) on sperm reserves and production of pubertal boars. The animals were randomly assigned to 4 diets containing 0.2, 5.0, 10.0 and 15.0 mg FB(1)/kg constituting the control, diets 1, 2 and 3, respectively, in a 6-month feeding trial. Dietary FB(1) above 5mg/kg significantly (P<0.05) reduced testicular and epididymal sperm reserves as well as the daily sperm production (DSP) per boar. The total caudal sperm reserves of the animals on diets 2 and 3 were about 70% of those on the control diet. The DSP of the animals on the control diet and diet 1 were significantly (P<0.05) higher than those on diets 2 and 3. The study revealed that male weaning pigs for breeding should not be exposed to dietary FB(1) higher than 5mg/kg for no suppression in sperm production and reproductive performance.

Cytotoxicity of fumonisin B(1) in spheroid and monolayer cultures of rat hepatocytes.

Fumonisin B(1) (FB(1)), the most prevalent member of toxins produced by several species of Fusarium molds, which occur mainly in maize, causes several fatal hepatopathies and nephropathies of animals. The current study was scrutinized to ascertain different cytotoxic and morphological transformations in rat hepatocytes induced by the treatments of diverse concentrations (300, 500, or 1000 microM) of fumonisin B(1) in vitro, using both monolayer and spheroid cultures. In each hepatocyte culture, the cytotoxicity of FB(1) was augmented in dose- and time-response manners. Morphological transformations among FB(1)-treated groups integrated accumulation of lipid droplets, cytoplasmic vacuolation in hepatocyte monolayers, and bleb formation in the hepatocyte spheroids. Additionally, electron microscopy revealed the loss of microvilli, mitochondrial swelling, and formation of lamellar membranous whorl in the vacuoles and bile canaliculi-like structures. Appearance of electron dense bodies in the monolayers, and loss of cell-to-cell contact in spheroids were depicted in 1000 microM FB(1)-treated hepatocytes. These outcomes insinuate different vital events in explaining morphological transformations in the cell membrane and organelles, induced by fumonisins in rat hepatocytes.