Aflatoxin-Guanine DNA Adducts and Oxidatively Induced DNA Damage in Aflatoxin-Treated Mice in Vivo as Measured by Liquid Chromatography-Tandem Mass Spectrometry with Isotope Dilution.

Dietary exposure to aflatoxin B1 (AFB1) is a significant contributor to the incidence of hepatocellular carcinomas globally. AFB1 exposure leads to the formation of AFB1-N7-guanine (AFB1-N7-Gua) and two diastereomers of the imidazole ring-opened 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxyaflatoxin B1 (AFB1-FapyGua) in DNA. These adducts lead to G → T transversion mutations with the ring-opened adduct being more mutagenic than the cationic species. Accurate measurement of these three adducts as biomarkers in DNA and urine will help identify dietary exposure to AFB1 as a risk factor in the development of hepatocellular carcinoma worldwide. Herein, we report an improved methodology for the measurement of AFB1-N7-Gua and the two diastereomers of AFB1-FapyGua using liquid chromatography-tandem mass spectrometry with isotope dilution. We measured the levels of these compounds in liver DNA of six control mice and six AFB1-treated mice. Levels varying from 1.5 to 45 lesions/106 DNA bases in AFB1-treated mice were detected depending on the compound and animal. No background levels of these adducts were detected in control mice. We also tested whether the AFB1 treatment caused oxidatively induced DNA base damage using gas chromatography-tandem mass spectrometry with isotope dilution. Although background levels of several pyrimidine- and purine-derived lesions were detected, no increases in these levels were found upon AFB1 treatment of mice. On the other hand, significantly increased levels of (5' R)- and (5' S)-8,5'-cyclo-2'-deoxyadenosines were observed in liver DNA of AFB1-treated mice. The impact of this work is expected to achieve the accurate measurement of three AFB1-DNA adducts and oxidatively induced DNA lesions as biomarkers of AFB1 exposure as germane to investigations designed for the prevention of aflatoxin-related hepatocellular carcinomas and for determining the effects of genetic deficiencies in human populations.

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.

The aflatoxin-detoxifizyme specific expression in the parotid gland of transgenic pigs.

Producing aflatoxin-detoxifizyme (ADTZ) in pigs to control the AFT contamination of pig feed is a new research strategy by transgenic technology. In this study, transgenic pigs specifically expressing ADTZ gene in the parotid gland were successfully produced by somatic cell nuclear transfer technology. The ADTZ activity in saliva of 6 transgenic pigs was found to be 7.11 ± 2.63 U/mL. The feeding trial with aflatoxin (AFT) results showed that there were significant difference about the serum biochemical index such as total protein (TP), albumin (ALB), globulin (GLB) contents and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity and AFT residues in serum and liver between the pigs in the test treatment (transgenic pigs) producing ADTZ and those in the positive control (P < 0.05). In order to investigate the inheritance of the transgene, 11 G1 transgenic pigs were successfully obtained. The ADTZ activity in saliva of 11 G1 transgenic pigs was found to be 5.82 ± 1.53 U/mL. The feeding trial with AFT results showed that the serum biochemical index containing TP, ALB and GLB contents and ALT and AST activity and AFB1 residues in serum and liver of the pigs in the test treatment (transgenic pigs) producing ADTZ were significantly different than those in the positive control (P < 0.05). The above results demonstrated that ADTZ produced in transgenic pigs could improve the effect of the AFT contamination of feed on pigs.

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.

Quantitative correlation of aflatoxin biomarker with dietary intake of aflatoxin in Tanzanian children.

The association between aflatoxin intake from maize-based weaning food and aflatoxin albumin adducts (AF-alb) was investigated in 148 Tanzanian children aged between 12 and 22 months, at 2 visits 6 months apart. At the first visit (storage season) there was a significant correlation at the individual level between AF-alb (geometric mean 43.2 pg/mg albumin) and aflatoxin intake (geometric mean 81.7 ng/kg b.w./d) through maize-based weaning food (r = 0.51, p < 0.01). Overall, this correlation was r = 0.43 (p < 0.01). The AF-alb level in weaning-age children in Tanzania closely reflects aflatoxin intake from maize in weaning food. Exposure levels suggest children may be at risk from aflatoxin associated health effects.

Exploring the uncertainties in cancer risk assessment using the integrated probabilistic risk assessment (IPRA) approach.

Current methods for cancer risk assessment result in single values, without any quantitative information on the uncertainties in these values. Therefore, single risk values could easily be overinterpreted. In this study, we discuss a full probabilistic cancer risk assessment approach in which all the generally recognized uncertainties in both exposure and hazard assessment are quantitatively characterized and probabilistically evaluated, resulting in a confidence interval for the final risk estimate. The methodology is applied to three example chemicals (aflatoxin, N-nitrosodimethylamine, and methyleugenol). These examples illustrate that the uncertainty in a cancer risk estimate may be huge, making single value estimates of cancer risk meaningless. Further, a risk based on linear extrapolation tends to be lower than the upper 95% confidence limit of a probabilistic risk estimate, and in that sense it is not conservative. Our conceptual analysis showed that there are two possible basic approaches for cancer risk assessment, depending on the interpretation of the dose-incidence data measured in animals. However, it remains unclear which of the two interpretations is the more adequate one, adding an additional uncertainty to the already huge confidence intervals for cancer risk estimates.

Effect of nanosilver on blood parameters in chickens having aflatoxicosis.

This experiment is designed to investigate the positive effects of commercial nanosilver compound on blood parameters in experimental aflatoxicosis in broiler chickens. For this, 270 one-day-old broiler chickens were randomly divided into six treatment groups with three replicates. The experimental groups were group A: chickens fed with basal diet; group B: chickens fed with 3 ppm productive aflatoxin in basal diet; groups of C, D, E and F received Mycoad (2.5 g/kg diet), Mycoad (2.5 g/kg diet) + productive aflatoxin (3 ppm), Nanocid (2500 ppm), and Nanocid (2500 ppm) + productive aflatoxin (3 ppm) in basal diet, respectively. Results revealed that some of the blood parameters such as mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration lymphocytes, neutrophils, basophils, monocytes, and eosinophils percentage were not affected in this experiment; whereas, hemoglobin percentage and white blood cell (WBC) count in all the groups fed with 3 ppm aflatoxin except nanocid + aflatoxin decreased significantly (p < 0.05). There are no significant differences between the groups that received nanocid + aflatoxin and mycoad + aflatoxin in hemoglobin percentage and WBC count parameters. The red blood cell count and hematocrit in chickens received aflatoxin were significantly lower than other groups (p < 0.05). Therefore, this study suggests that nanocid similar as mycoad can be useful in reducing the adverse effects of aflatoxin on blood parameters in chickens affected with aflatoxicosis.

Effects of aflatoxins on performance and exocrine pancreas of broiler chickens.

The aim of this research was to evaluate, on a weekly basis, the effects of aflatoxins on the activity of digestive enzymes (alpha-amylase, lipase, and trypsin) in the pancreas as well as on the performance and histology of pancreas in broiler chickens over the course of 42 days. One thousand and eighty 1-day-old male Cobb broilers were divided into four treatments with 18 replicates and 15 birds per replicate (i.e., 270 broilers per treatment). Treatments were established according to the amount of aflatoxins added to the diet, as follows: T1 = 0 mg of aflatoxins per kilogram of feed (mg/kg); T2 = 0.7 mg/kg; T3 = 1.7 mg/kg; and T4 = 2.8 mg/kg. Pancreas sample collection was performed from one bird out of each replicate at 7, 14, 21, 28, 35, and 42 days of experiment, which yielded a total of 18 samples per treatment on each collection. Each sample was homogenized in distilled water, frozen in liquid nitrogen, lyophilized, and stored at -20 C until analysis. Performance parameters (body weight, feed consumption, and feed conversion rate) were measured at 21, 35, and 42 days of experiment. At the end of the experiment (42 days), six birds from each treatment were randomly chosen for histologic evaluation of the pancreas. The presence of aflatoxins in the diet induced a negative effect on all performance parameters. The pancreatic activity of lipase and alpha-amylase were significantly increased in treatments T3 and T4, while the specific activity of trypsin was only affected during treatment T4. In addition, several histologic changes were observed in the pancreas of birds receiving aflatoxin-contaminated feed. Aflatoxins present in the feed determined an increase in the activity of pancreatic enzymes in broilers, affecting the digestibility of the diet, thereby leading to losses in performance and productivity.

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.

Effects of aflatoxin on liver and protective effectiveness of esterified glucomannan in Merino rams.

The effects of total aflatoxin (AF) given orally on liver in Merino rams were studied. In addition, this study was conducted in order to evaluate the efficacy of an esterified glucomannan (EG) for protection against aflatoxicosis. One-year-old 32 Merino rams were divided into four equal groups. The control group (C) was fed with the commercial feed. The AF group was fed with commercial feed plus 250 µg/day of total AF. The EG group was fed with commercial feed plus 2 g/day of EG. The AF + EG group was fed with commercial feed plus 250 µg/day of total AF and 2 g/day of EG. After feeding period, tissue samples were taken from the liver in order to perform histological analyses. Vacuolar degeneration with small and large droplets and hydropic degeneration in hepatocytes were observed in the AF group. The ceroid pigmentation was observed in macrophages in groups or one by one. It was observed that the fat rate in hepatocytes was 2.6% in the C group, 35.5% in the AF group, 2.9% in the EG group, and 9.6% in the AF + EG group. In conclusion, the adverse effects caused by aflatoxicosis on the liver could be ameliorated by adding EG to the ration.

Effects of feeding corn naturally contaminated with aflatoxin B1 and B2 on hepatic functions of broilers.

The purpose of this study was to evaluate the effects of feeding corn naturally contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) on serum biochemical parameters, hepatic antioxidant enzyme activities, and pathological lesions of broilers. In total, 1,200 Cobb male broilers were randomly allocated into 5 treatments, with 8 replicates per treatment and 30 birds per replicate, in a 42-d experiment. The dietary treatments were as follows: control, 25, 50, 75, and 100% contaminated corn groups. Results showed that serum aspartate aminotransferase activity in the 75 and 100% contaminated groups were higher than that in the control group on d 21 (P < 0.05). Decreased content of hepatic total protein and increased activities of hepatic glutathione reductase and glutathione-S-transferase were observed as the percentage of contaminated corn increased (P < 0.05). The activity of superoxide dismutase and the content of hepatic malondialdehyde increased when the broilers were fed with more than 50% contaminated corn (P < 0.05). A reduction in glutathione peroxidase level was observed in the AFB(1)- and AFB(2)-contaminated groups on d 21 (P < 0.05). The average pathological lesion scores and apoptosis rate of liver cells increased as the concentration of dietary AFB(1) and AFB(2) increased. Ultrastructural changes were found in the livers of broilers fed 100% contaminated corn. In conclusion, diets containing AFB(1) and AFB(2) could induce pathological lesions in the livers, slightly change the serum biochemical parameters, and damage the hepatic antioxidant functions when the inclusion of AFB(1)- and AFB(2)-contaminated corn reached or exceeded 50%.

Aflatoxin exposure and child nutrition: measuring anthropometric and long-bone growth over time in Nepal.

BACKGROUND: Naturally occurring aflatoxins may contribute to poor growth and nutritional statuses in children. OBJECTIVES: We analyzed the relationship between contemporary and lagged aflatoxin exposure and 1) length-for-age z-score (LAZ); and 2) length, knee-heel length, stunting, weight-for-age z-score (WAZ), and weight-for-length z-score (WLZ). METHODS: We conducted a longitudinal birth cohort study involving 1675 mother-infant dyads in rural Nepal. Participants were repeatedly visited from pregnancy to 2 years of age (2015-2019). One blood sample was collected during pregnancy and 4 samples were collected from the children at 3, 6, 12, and 18-22 months of age to measure concentrations of aflatoxin B1 (AFB1)-lysine adduct. Multivariate linear fixed-effects and logistic models with generalized estimating equations were used to identify associations between child growth and aflatoxin exposure. RESULTS: AFB1-lysine adducts were detected in the majority of children (at 3 months, 80.5%; at 6 months, 75.3%; at 12 months, 81.1%; and at 18-22 months, 85.1%) and in 94.3% of pregnant women. Changes in contemporary ln child AFB1-lysine adduct concentrations were significantly associated with changes in LAZ (ß, -0.05; 95% CI, -0.09 to -0.02; P = 0.003), length (ß, -0.19; 95% CI, -0.29 to -0.10; P < 0.001), knee-heel length (ß, -0.09; 95% CI, -0.13 to -0.05; P < 0.001), and WAZ (ß, -0.04; 95% CI, -0.07 to -0.005; P = 0.022). Serum aflatoxin concentrations were associated with stunting (OR, 1.18; 95% CI, 1.05-1.32; P = 0.005). Similar results were found in the models using changes in contemporary ln AFB1 adjusted for changes in child weight, with significant associations with changes in WLZ (ß, -0.07; 95% CI, -0.10 to -0.03; P < 0.001). Changes in time-lagged ln AFB1 (unadjusted and adjusted for changes in child weight) were associated with changes in length and knee-heel length. CONCLUSIONS: Our results add to the growing body of evidence confirming chronic aflatoxin exposure and suggest that exposure is significantly correlated with various negative growth outcomes, which may vary by child weight status. This trial was registered at clinicaltrials.gov as NCT03312049.

Effects of aflatoxin chronic intoxication in renal function of laying hens.

Aflatoxins (AF) have a high impact in both human and animal health, causing significant economic losses in the poultry industry, especially by diminution of avian growth, feed efficiency, and product quality. Aflatoxins affect the whole organism, particularly liver and kidney. The objective of this study was to evaluate renal function alterations in laying hens during chronic AF ingestion. Randomly, 84 Leghorn Hy-Line laying hens (13 wk old) were assigned into 4 experimental groups (n = 21): 0.0, 0.5, 1.0, and 1.5 mg of AF/kg of feed. The AF (B(1), B(2), G(1), and G(2)) was obtained from 2 toxicogenic local strains of Aspergillus flavus grown in corn grains; the grain was sterilized, ground, and added to basal diets to achieve the selected AF concentrations. Hens ingested, during 17 and 42 wk, feed contaminated with AF. Data were analyzed in a 4 x 2 factorial arrangement. Hens were anesthetized, ureteral urine samples were collected, and arterial blood samples were taken. The renal functional tests were evaluated by spectrophotometric and flame photometric methods, including a) Na, K, Ca, and phosphate fractional excretions; b) renal hemodynamic studies, glomerular filtration rate and renal plasma flow by inulin and p-aminohippurate clearances, respectively; and c) identification of macroscopic and histopathologic lesions. The hens intoxicated at all levels of AF showed significant (P < 0.05) increases in Ca, Na, and phosphate fraction excretions. Sodium and phosphates were excreted in a pattern of response time-dose. However, glomerular filtration rate exhibited a significant reduction (P < 0.05). The K fractional excretion and renal plasma flow remained unchanged. These results suggest that AF chronic ingestion affects renal functions of laying hens and induces Ca(++), (-3)PO(4), and Na(+) losses, which are of great concern to the poultry industry.

Burden of disease associated with dietary exposure to carcinogenic aflatoxins in Portugal using human biomonitoring approach.

Human biomonitoring is an important tool to assess human exposure to chemicals, contributing to describe trends of exposure over time and to identify population groups that could be under risk. Aflatoxins are genotoxic and carcinogenic food contaminants causing hepatocellular carcinoma, the third leading cause of cancer deaths worldwide. In Portugal, scarce data are available regarding exposure to aflatoxins and no previous study used human biomonitoring data to comprehensively characterize the associated burden of disease. 24 h urine and first-morning urine paired samples were collected by 94 participants and were analyzed by liquid chromatography-tandem mass spectrometry for the quantitative determination of aflatoxins (B1, B2, G1, G2 and M1). Deterministic and probabilistic models were developed to assess the Portuguese exposure to aflatoxins and to estimate the health impact of this exposure, estimating the attributed Disability-Adjusted Life Years (DALYs). Aflatoxins were detected in a maximum of 13% (AFB1), 16% (AFB2), 1% (AFG1), 2% (AFG2) and 19% (AFM1) of the urine samples. Data obtained through the probabilistic approach revealed an estimated mean probable daily intake of 13.43 ng/kg body weight per day resulting in 0.13 extra cases of hepatocellular carcinoma, corresponding to mean annual DALYs of 172.8 for the Portuguese population (10291027 inhabitants). The present study generated for the first time and within a human biomonitoring study, reliable and crucial data to characterize the burden associated to the exposure to aflatoxins of the Portuguese population. The obtained results constitute an imperative support to risk managers in the establishment of preventive policy measures that contribute to ensure public health protection.

Toxico-pathological effects in rats induced by concurrent exposure to aflatoxin and cypermethrin.

The objective of the present study was to explore modification in toxico-pathological responses of rats toward aflatoxins in the presence of cypermethrin. A total of 120 adult male rats divided into six equal groups received AF and cypermethrin alone or in different combinations. AF was administered daily into rats with a stomach tube at dose rates of 0, 0.5 and 1.0mg/kg AFB1. Cypermthrin was administered in the feed at dose levels of 0 and 500mg/kg. Rats administered AF alone showed depression, decrease in feed intake, body weight and loose feces. Livers exhibited fatty change, necrosis, newly formed bile ducts and increased diameter of hepatocytes and their nuclei. Lesions in kidney included tubular necrosis and pink homogeneous tubular casts. Serum ALT and creatinine concentrations increased while those of total proteins, albumin, serum cholesterol and triglycerides decreased. Rats fed cypermethrin only had decreased feed intake and body weight. Hepatocytes showed fatty change and cellular necrosis. A concurrent administration of AF with cypermethrin indicated a potentiation of the AF toxicity reflected by increased severity of clinical signs, mortality of the rats and decreased body weights. Kidneys' relative weight also showed an equivocal interaction between the two toxicants. Other parameters studied did not show significant differences between the rats administered AF alone or concurrently with cypermethrin.

Effects of turmeric (Curcuma longa) on the expression of hepatic genes associated with biotransformation, antioxidant, and immune systems in broiler chicks fed aflatoxin.

The objective of the present study was to evaluate the efficacy of curcumin, an antioxidant found in turmeric (Curcuma longa) powder (TMP), to ameliorate changes in gene expression in the livers of broiler chicks fed aflatoxin B(1) (AFB(1)). Four pen replicates of 5 chicks each were assigned to each of 4 dietary treatments, which included the following: A) basal diet containing no AFB(1) or TMP (control), B) basal diet supplemented with TMP (0.5%) that supplied 74 mg/kg of curcumin, C) basal diet supplemented with 1.0 mg of AFB(1)/kg of diet, and D) basal diet supplemented with TMP that supplied 74 mg/kg of curcumin and 1.0 mg of AFB(1)/kg of diet. Aflatoxin reduced (P < 0.05) feed intake and BW gain and increased (P < 0.05) relative liver weight. Addition of TMP to the AFB(1) diet ameliorated (P < 0.05) the negative effects of AFB(1) on growth performance and liver weight. At the end of the 3-wk treatment period, livers were collected (6 per treatment) to evaluate changes in the expression of genes involved in antioxidant function [catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST)], biotransformation [epoxide hydrolase (EH), cytochrome P450 1A1 and 2H1 (CYP1A1 and CYP2H1)], and the immune system [interleukins 6 and 2 (IL-6 and IL-2)]. Changes in gene expression were determined using the quantitative real-time PCR technique. There was no statistical difference in gene expression among the 4 treatment groups for CAT and IL-2 genes. Decreased expression of SOD, GST, and EH genes due to AFB(1) was alleviated by inclusion of TMP in the diet. Increased expression of IL-6, CYP1A1 and CYP2H1 genes due to AFB(1) was also alleviated by TMP. The current study demonstrates partial protective effects of TMP on changes in expression of antioxidant, biotransformation, and immune system genes in livers of chicks fed AFB(1). Practical application of the research is supplementation of TMP in diets to prevent or reduce the effects of aflatoxin in chicks fed aflatoxin-contaminated diets.

Evaluation of the ability of a feed additive to ameliorate the adverse effects of aflatoxins in turkey poults.

1. A study was conducted to evaluate the possible protective effect of a feed additive containing aluminosilicate and phytogenic substances against the adverse effects of aflatoxins in turkey poults. 2. Dietary treatments (6) were given to turkey poults from d 1 to d 42 of age. From d 1 to 21 the dietary treatments were as follows: 1, negative control, no aflatoxins or feed additive added; 2, feed additive control, 1 kg/t feed additive, no aflatoxins; 3, 250 ppb (microg/kg) aflatoxins, no feed additive; 4, 250 ppb aflatoxins + 1 kg/t feed additive; 5, 500 ppb aflatoxins, no feed additive; and 6, 500 ppb aflatoxins + 1 kg/t feed additive. From d 22 to 42, the dietary concentration of the feed additive was increased from 1 to 2 kg/t in all treatment groups receiving the feed additive (2, 4 and 6), while keeping constant the dietary concentrations of aflatoxins. 3. Aflatoxins at 250 ppb did not cause adverse effects on performance but affected certain toxicopathological parameters. At 500 ppb, adverse effects on performance and several toxicological parameters were observed. 4. Some of the adverse affects were partially or completely overcome by supplementation with the feed additive, including amelioration of the performance parameters, suppression of mortality and correction of the immunological alterations induced by the exposure to the aflatoxins.

Effects on meat quality and black bone incidence of elevated dietary vitamin levels in broiler diets challenged with aflatoxin.

Vitamins play an essential role in broiler nutrition. They are fundamental for normal metabolic and physiological process, and their requirements for poultry are not fixed and can be affected by multiple factors. In contrast, mycotoxins are a challenging issue because they hinder performance and the immune system. Vitamin supplementation above minimum requirements would permit improvement in productive potential, health, bone and meat quality in a situation of mycotoxin challenge. The objective of this study was to determine the influence of optimum vitamin nutrition in diets contaminated with aflatoxin in broilers from 1 to 44 days of age. A total of 1800 Cobb 500 male chicks were randomized to 15 sets of eight treatment groups, each containing 15 birds using a 2 × 2 × 2 factorial design (commercial vitamin levels and high vitamin levels, two levels of aflatoxin - 0 and 0.5 ppm with binder levels of 0 and 10 000 mg/kg). The mash diets were corn and soybean meal based, formulated according to commercial practices. Feed intake, weight gain and feed conversion were analyzed for birds from 1 to 44 days of age. To determine carcass characteristics (carcass yield, breast yield and leg yield) and black bone syndrome, two birds were slaughtered from each group at 45 days. Other analyses included breast tenderness, water loss by dripping and malonaldehyde concentrations. The results demonstrated that broilers that were fed high levels of vitamins showed better weight gain, feed conversion, carcass yield and breast yield than broilers that were fed diets with commercial vitamin levels (P < 0.05); also, broilers that were fed diets containing 0.5 ppm aflatoxin had lower weight gain, carcass yield and breast yield (P < 0.05). The use of 10 000 mg/kg of binder improved (P < 0.05) feed conversion throughout the rearing period. We conclude that aflatoxin negatively affects performance and carcass yield; however, feeding optimum vitamin nutrition improved these performance traits.

Aflatoxicosis in chickens (Gallus gallus): an example of hormesis?

Poultry has commonly been considered highly susceptible to aflatoxins. However, among domestic fowl there is wide variability in specific species sensitivity to these mycotoxins. Comparative toxicological studies in avian species have shown that ducklings and turkey poults are the most sensitive species to aflatoxins, quails show intermediate sensitivity, whereas chickens are the most resistant. Hormesis is a dose-response phenomenon characterized by low-dose stimulation and high-dose inhibition. The low-dose stimulation is typically maximal at only about 30 to 60% greater than controls. Hormesis has been noted in regards to changes in body weight in numerous studies, including those performed for the US National Toxicology Program, with over 50 chemicals. The present paper assesses how relatively low levels of aflatoxin consumption in feed may affect the growth rate of chickens. In general, multiple independent investigations have shown that such aflatoxin consumption affects growth in a hormetic-like biphasic manner with a low dose stimulation and a high dose inhibition. Such observations were then generalized to other toxic agents and animal models, suggesting that low doses of stressor agents induce adaptive responses as reflected in accelerated growth rates. The implications of such hormetic dose responses are briefly discussed.

Growth, haematology, blood constituents and immunological status of lambs fed graded levels of animal feed grade damaged wheat as substitute of maize.

The aim of this study was to explore possibilities of utilization of animal feed grade damaged wheat (ADW) in lamb feeding, and assess the effect of ADW and its aflatoxin on intake, growth, haematology, blood biochemical constituents and immunological status. The ADW is a slightly mouldy feed resource, which is not suitable for human consumption. The experimental ADW contained dry matter (DM) 964, organic matter 974, crude protein 153, cellulose 205 and lignin 24, and starch 732 g/kg DM. ADW also contained aflatoxin B1 50 microg/kg due to mould infestation. Thirty-five weaner lambs (90 +/- 15 days of age and 16.1 +/- 0.82 kg body weight) in a randomized design were fed for 91 days on one of four composite feed mixtures (roughage to concentrate ratio of 25:75) containing 0, 118, 235, 353 or 470 g/kg ADW, which replaced equal amounts of maize and at these inclusion levels ADW replaced 0%, 25%, 50%, 75% and 100% maize in lamb diets respectively. Dry matter intake (DMI) was similar in different level of ADW fed lambs but ADW inclusion linearly (p = 0.016) reduced DMI. Average daily gain (g/day) was higher (p = 0.038) in lambs fed 353 g ADW diet. Haematological attributes viz. WBC, haemoglobin (Hb) and mean corpuscular volume did not affect by ADW feeding whereas it increased haematocrit, mean cell Hb and decreased neutrophil, RBC counts and mean cell Hb concentration. Blood glucose and urea-N increased whereas albumin and protein level reduced by ADW feeding. ADW feeding of lambs did not affect serum IgG level. The activities of serum aspartate aminotransferase, alkaline phosphates and acid phosphates were not affected, whereas alanine aminotransferase increased linearly (p = 0.001) with increasing levels of ADW. It is concluded that ADW containing aflatoxin B1 50 microg/kg DM can safely be incorporated in growing lamb feeding up to 353 g/kg diet without affecting growth and cellular immunity, however ADW may induce a transient alteration of hepatic enzymatic activities. Further aflatoxin content of the diet should be kept within permissible limits of respective country.