Aflatoxin Toxicity Research Articles

Significance of Aflatoxins in Rural and Global Health: Concern for Agricultural Workers

Aflatoxins B1, B2, G1, and G2 are highly toxic and carcinogenic secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus fungi. Aflatoxin B1 (AFB1) has been recognized as one of the most potent chemical carcinogens [1]. The acute toxicity, mutagenicity, and carcinogenicity of aflatoxins are associated with the presence of the 8,9 double bond and the terminal cyclopentanone ring (Figure 1). The order of the severity of acute and chronic toxicity is B1> G1> B2> G2, reflecting the role of the 8,9 double bond and the greater potency associated with the cyclopentanone ring of the B series [2].

Biological Effect of Naturally Occurring Mycotoxins Fed to Poults Reared to 21 Days of Age

3 Abstract: A trial was conducted to observe potential changes in turkey poults reared to 21 d by feeding diets with naturally occurring mycotoxins. Two sources of corn, one each with Aflatoxin (AFL) and Deoxynevalenol (DON), were obtained. Treatments (T) were: 1) clean corn (C), 2) AFL (A), 3) DON (D) and 4) ½A+½D (AD). A marker (celite, 1.5%) was added for 21 d AMEn determination. A basal ration with ingredients except corn was mixed. The basal and corn were mixed for T feeds. Feed was pelleted and crumbled. Male poults were placed into 24 pens in petersyme batteries (7 birds/pen; 6 pens/T). Feed consumption, by pen and BW were determined by wk. At 21 d, birds were euthanized. Heart (H), spleen (S), gizzard (G), liver (L) and bursa of fabricious (B) were weighed and Breast Muscle (BM) collected for color analysis. Light microscopic analysis of HE AD = 2,758±29). Relative (R) S weight of D (0.11) fed birds was reduced versus A (0.14) but not C or AD (0.12, 0.13±0.006 g/g). The RL weight of birds fed A (2.26) and AD (2.52) were reduced versus C (2.68±0.07g/g). The A fed birds had reduced SA (by OD). Mortality, RH, RB and RG weights, G score and BM colors were not affected. There were no differences in AB. The L of the A fed birds had hepatic parenchyma with diffuse degenerative changes. The hepatocytic nuclei were swollen and had condensed nucleoli. Some hepatic cords had hepatocyte necrosis. There was some sinusoidal congestion with dilatation/congestion of few central veins. These lesions were suggestive of aflatoxin toxicity. The effects of AFL and DON in this study were reflective of what has been reported in the literature. Feeding naturally occurring mycotoxins to poults can be used as a model to study interventions.

Oral administration of piperine for the control of aflatoxin intoxication in rats

Aflatoxins are mycotoxins that have important toxic effects on human and animal health, even if consumed at low doses. The oral administration of piperine (1.12 mg/kg) during 23 days in rats seemingly interfered with the toxicity of aflatoxins, decreasing hepatic injuries and the leukocyte depletion in experimentally intoxicated animals.

Evaluation of the efficacy of esterified glucomannan, sodium bentonite, and humic acid to ameliorate the toxic effects of aflatoxin in broilers

A study was conducted to determine the efficacy of esterified glucomannan, sodium bentonite, and humic acid in counteracting the toxic effects of aflatoxin in a naturally contaminated diet fed to broilers. Seven-day-old chicks were randomly assigned to 1 of the 9 dietary treatments. The treatments were as follows: 1) control; 2) naturally contaminated diet with aflatoxin; 3, 4, 5, 6, and 7) naturally contaminated diet with aflatoxin supplemented with 0.2%, 0.4%, 0.6%, 0.8%, and 1.0% humic acid, respectively; 8 and 9) naturally contaminated diet supplemented with 0.5% sodium bentonite and 0.1% esterified glucomannan, respectively. Compared with the control, the naturally contaminated diet significantly increased feed consumption and resulted in poor feed efficiency. Increased relative weights of liver and decreased relative weights of bursa of Fabricius were observed in chicks fed the naturally contaminated diet. Further, feeding a contaminated diet was associated with significant decreases in serum albumin, total protein, uric acid, and cholesterol. Compared with the control, the naturally contaminated diet significantly increased the activities of \gamma-glutamyl transferase, lactate dehydrogenase, and aspartate amino transferase. Humic acid showed protective effects on feed efficiency and against liver and bursa of Fabricius damage, as well as some of the serum enzyme activities and serum biochemical changes associated with aflatoxin toxicity.

Evaluation of high-grade sodium bentonite on performance and immune status of broilers, fed ochratoxin and aflatoxin

An experimental trial with 2×2×2 factorial design was conducted to assess the individual and combined effects of mycotoxins including ochratoxin A (OTA) (0 and 1.0 mg/kg), aflatoxin B1 (AFB1) (0 and 0.5 mg/kg) and high-grade sodium bentonite (HGSB) (0 and 1.0%) in broilers. Significant depression of body weight, feed consumption, serum protein and serum albumin were noticed due to OTA, AFB1 and OTA+AFB1. The relative weights of pancreas, spleen and bursa were not altered significantly either by inclusion of OTA, AFB1, OTA+AFB1 or HGSB. Increases in the relative weights of liver and gizzard were observed in OTA, AFB1 and OTA+AFB1. Decreases in serum protein levels and increases in gamma glutamyl transferase were noticed in the OTA+AFB1 group. Also decreases in serum protein levels for alanine amino transferase and thymus were observed. The antibody titres against Newcastle Disease and Infectious Bursal Disease were significantly (P<0.05) decreased in all the treatment groups compared to control. HGSB reduced the toxicity of aflatoxin and marginally ameliorated the effect of OTA+AFB1 on some parameters.

Simultaneous evaluation of toxicities using a mammalian cell array chip prepared by photocatalytic lithography

A prototype of a mammalian cell array chip was developed on a flat glass surface. A superhydrophilic (water contact angle = 5°)/highly hydrophobic (120°) pattern was prepared on a fluorinated polymer-coated glass surface by means of photocatalytic lithography, and A549 (a human alveolar epithelial cell line), Hep G2 (a human hepatoma cell line) and mouse fibroblast 3T3 cells were inoculated onto the superhydrophilic regions. The cell populations were confined in the superhydrophilic regions for at least 24 h and separated from each other for at least one week. Organ-specific toxicity of aflatoxin B 1 and non-specific toxicity of adriamycin were successfully detected by using the cell array chip.

Diet and aflatoxin toxicity.

Diet and aflatoxin toxicity.

Toxicity, biochemical effects and residue of aflatoxin B 1 in marine water-reared sea bass ( Dicentrarchus labrax L.)

Aflatoxicosis and resulting epizootic hepatoma have been reported among a wide range of fish where Aspergillus species-contaminated foodstuffs are incorporated into the diet. Aflatoxin B 1 (AFB 1) is among the most potent known hepatotoxins and carcinogens. Therefore, it is an important potential toxicant to the most of the popularly cultured fish species. The present study was undertaken to assess the susceptibility and toxicity of AFB 1 to sea bass ( Dicentrarchus labrax L.), by behavioral and biochemical evaluations. The estimated oral acute median lethal concentration (96 h LC 50) of AFB 1 for sea bass was 0.18 mg/kg bwt. The abnormal behavioral responses and signs of toxicity were described. The prolonged oral administration of 0.018 mg/kg bwt AFB 1 to sea bass for 42 successive days induced a significant increase in serum transaminases and alkaline phosphatase activities, and significant decrease in plasma proteins. Residual AFB 1 was detected at high levels (≈5 ppb) in fish musculature at the end of the experimental period. We conclude that marine water sea bass is a species highly sensitive to AFB 1. In addition, consumption of sea bass reared on AFB 1-contaminated diet could have a negative health impact on human health.

Effects of Two Different Types of Montmorillonite on Growth Performance and Serum Profiles of Broiler Chicks during Aflatoxicosis

Experiments were conducted to compare the efficacy of montmorillonite (M) and montmorillonite nanocomposite (MN) to reduce the toxicity of aflatoxin (AF) in broiler chicks from 0 to 42 days of age. A total of 240 chicks were assigned to 6 dietary treatment groups (0 g of adsorbents and 0 mg of AF/kg feed, 3 g of M/kg feed, 3 g of MN/kg feed, 0.11 mg of AF/kg feed, 0.11 mg of AF plus 3 g of M/kg feed, and 0.11 mg of AF plus 3 g of MN/kg feed). Compared to the control, AF alone significantly decreased ADG and feed efficiency. Marked improvements in performance by the addition of MN to AF diet demonstrated the ability of MN to reduce the toxic effects of AF. However, the addition of M can not diminish the growth inhibitory effects of AF. AF intake markedly increased relative weights of liver, kidney, spleen, and pancreas, and resulted in significant alterations of serum biochemical values and enzymatic activities. Chicks fed MN with AF diet had apparent recovery or restoration of AF-induced organ lesions and aberrations in serum profiles, whereas chicks fed M with AF diet had relative organ weights and serum profiles similar to those of chicks fed AF alone, which indicated beneficial effects of MN and nonprotective effects of M. These findings suggest that feeding MN can effectively prevent the adverse effects associated with aflatoxicosis in broiler chicks.

Induction of meiotic micronuclei in spermatocytes in vivo by aflatoxin B1: Light and transmission electron microscopic study in Swiss mouse

Dietary aflatoxins produce a disease state known as aflatoxicosis, and disruption of spermatogenesis is one of its serious consequences. Towards finding the cellular targets in spermatogenic compartment for aflatoxin toxicity, aflatoxin B 1 (AFB 1) was administered to 90-day-old Swiss mouse through i.p. route at a daily dose of 20 μg per kg body weight for 7, 15, 35 and 45 days. The testis and epididymis were subjected to light- as well as transmission electron microscopic analysis. One of the newer observations was occurrence of meiotic micronucleate giant spermatocytes in seminiferous epithelium and epididymal lumen. The origin of these cells could be traced to imminent disruption of spindle apparatus during meiotic division of spermatocytes, resulting in lagging of chromosome bivalents or replicated univalents. Such chromosomes appeared to undergo condensation and become micronuclei. Thus, this study reports that aflatoxin exposure would result in generation of meiotic micronucleate giant spermatocytes.

Efficacy of Tunisian montmorillonite for in vitro aflatoxin binding and in vivo amelioration of physiological alterations

Aflatoxins (AFs), a group of closely related, extremely toxic mycotoxins produced by Aspergillus flavus and A. parasiticus, can occur as natural contaminants of food and feeds. AFs have been shown to be hepatotoxic, carcinogenic, mutagenic and teratogenic to different animal species. In the current study Tunisian montmorillonite (TM) was evaluated versus AFs caused toxicities in human colon cancer cell line (Caco-2) and in rats as a sensitive model. The aims of this study were threefold: (1) to evaluate the efficacy of TM to adsorb AFs from aqueous solution, (2) to protect Caco-2 cell line against AFs-induced cytotoxicity, DNA fragmentation and caspase-3-dependent apoptosis induction and (3) to evaluate the protective effect of TM against AFs toxicity in Sprague–Dawley rats. In the in vitro study, three concentrations of TM (0.5, 1, and 2 mg/L aqueous solution) and three concentrations of AFB 1 (10, 20, 50 mg/L) were tested. The results indicated that TM had a high capacity of adsorbing AFB 1 at different concentrations tested. The quantity adsorbed was 19.26 mg of AFB 1/g of TM. TM protects Caco-2 cells, inhibits DNA fragmentation and reduces caspase-3 enzymes activity in aflatoxin-treated Caco-2 cell culture. The in vivo results indicated that rats fed AFs-contaminated diet (2.5 mg kg − 1 diet) for 2 weeks showed severe serum biochemical changes typical of aflatoxicosis. Rats treated with TM alone (5%) or in combination with aflatoxin were comparable to the control. The TM was found to be safe and successful in the prevention of aflatoxin toxicity and cytotoxicity.

Aflatoxins: Detection, toxicity, and biosynthesis

Aflatoxins are toxic and carcinogenic secondary metabolites produced mainly byAspergillus flavus andAspergillus parasiticus. The aflatoxins present in food and feed are hazardous to both human and animal health. A number of studies have been conducted on the detection, toxicity, biosynthesis, and regulation of aflatoxins due to the discovery of serious aflatoxicosis in farm animals, and the presence of aflatoxins in many food products. There are many reviews that focus on the biosynthesis of aflatoxin, yet there are few examinations of the overall aspects of aflatoxins, including detection, toxicity, and the regulation on biosynthesis. Thus, the goal of this article is to give an overview of the overall aspects of aflatoxins. This review consists of four parts; i) detection methods for aflatoxins, ii) the toxicity mechanism of aflatoxin B1, iii) gene cluster for aflatoxin biosynthesis, and iv) the regulation of aflatoxin biosynthesis.

Efficacy of two different types of montmorillonite to reduce the toxicity of aflatoxin in pigs

Experiments were conducted to compare the efficacy of montmorillonite (M) and montmorillonite nanocomposite (MN) to reduce the toxicity of aflatoxin (AF) in growing/finishing pigs. A total of 144 weaned pigs were assigned to six dietary treatment groups (0 g of adsorbents and 0 mg of AF/kg feed; 3 g of M/kg feed; 3 g of MN/kg feed; 0.11 mg of AF/kg feed; 0.11 mg of AF plus 3 g of M/kg feed; and 0.11 mg of AF plus 3 g of MN/kg feed). Compared to the control, AF alone decreased average daily gam (ADG) by 12.9% (P < 0.05), and increased feed/gain ratio by 7.54% (P < 0.05). Improvements in average daily gain and feed/gain ratio by 13.0 and 4.80% (P < 0.05) by the addition of MN to the AF diet demonstrated the ability of MN to reduce the toxic effects of AF. However, the addition of M did not diminish the growth inhibitory effects of AF (P > 0.05). AF intake increased relative weights of liver, kidney, spleen and pancreas by 8.24, 27.3, 41.2 and 42.9% (P < 0.05), and resulted in significant alterations of serum biochemical values and enzymatic activities (P < 0.05). Pigs fed the MN with AF diet had appreciable improvements in AF‐induced organ lesions and aberrations in serum profiles (P < 0.05), whereas pigs fed the M with AF diet had relative organ weights and serum profiles similar to those of pigs fed AF alone (P > 0.05), which indicated beneficial effects of MN and non‐protective effects of M. These findings suggested that feeding MN can effectively prevent the negative effects associated with aflatoxicosis in pigs.

Protective effects of melatonin and N‐acetylserotonin on aflatoxin B1‐induced lipid peroxidation in rats

Aflatoxin B1 (AFB1) is a potent hepatotoxic and hepatocarcinogenic mycotoxin. Reactive oxygen species are considered to participate in the main mechanism of aflatoxin toxicity. Melatonin (Mel) is a hormone which has antioxidative activities. N-acetylserotonin (NAc-5HT) is an immediate precursor of Mel. Melatonin is documented to be completely safe in humans and animals. The aim of our study was to examine the potential protective effects of Mel or NAc-5HT against lipid peroxidation (LPO), caused by AFB1 in male Wistar rats. Mel and NAc-5HT were intraperitoneally (i.p.) injected for 3 weeks in late afternoon (16:00-18:00) injections (20 mg kg(-1) BW/daily). AFB1 (50 microg kg(-1) BW/daily) was administered i.p. 6 h prior to indoleamine injections. Concentrations of malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA), as an index of LPO, were measured in liver, brain, lung, testis and kidney homogenates. The level of LPO in tissue homogenates was expressed as the amount of MDA + 4-HDA (nmol) per milligram of protein. AFB1 increased LPO in the liver, lung, brain and testis, but not the kidney. The increase of LPO caused by AFB1 injections was completely prevented by either Mel or NAc-5HT in all the tissues examined. Melatonin can be considered as a protective pharmacological agent in intoxication with AFB1 and the protective effect of NAc-5HT against aflatoxin-induced LPO broadens the knowledge about its antioxidative properties.

Keap1 eye on the target: chemoprevention of liver cancer

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, causing nearly 600,000 deaths each year. Increased risk of HCC due to chronic infection with hepatitis B virus (HBV) and exposure to dietary aflatoxins is responsible for many of these deaths. Prevention strategies targeting HBV infection and aflatoxin exposure could dramatically impact the rates of HCC. Universal HBV vaccination programs have begun in some high-risk areas. Strategies to reduce aflatoxin contamination in food stores have also been implemented. However, complete elimination of aflatoxin contamination might not be possible. For this reason, chemoprevention strategies which alter aflatoxin disposition are a practical strategy to reduce the incidence of HCC in populations with high dietary aflatoxin exposure. The mechanisms of aflatoxin-induced hepatocarcinogenesis are well known. This knowledge provides the basis for evaluation of both exposures to aflatoxin, as well as modulation of aflatoxin disposition by chemopreventive agents. Products of aflatoxin DNA damage and toxicity as well as other metabolites can be used as biomarkers to evaluate modulation of aflatoxin disposition. Modulation of aflatoxin disposition can be achieved through induction of conjugating and cytoprotective enzymes. Many of these enzymes are regulated through Kelch ECH-associating protein 1 (Keap1)-NF-E2-related factor 2(Nrf2)-antioxidant response element (ARE) signaling, making this pathway an important molecular target for chemoprevention. Rodent studies have identified several classes of chemopreventive agents which induce cytoprotective genes. These inducers include phenolic antioxidants, dithiolethiones, isothiocyanates, and triterpenoids. Furthermore, clinical interventions have shown that inducers of Keap1-Nrf2- ARE signaling increase cytoprotective enzyme expression, resulting in modulation of aflatoxin disposition. Much work remains to be done in order to take promising chemopreventive agents from preclinical evaluation to application in at-risk populations. However, appropriately designed clinical trials will aid in this process, which can have profound impact on the incidence of HCC.

Biodiversity of Aspergillus section Flavi in the United States: A review

Fungi belonging to Aspergillus section Flavi are of great economic importance in the United States due to their ability to produce toxic and carcinogenic aflatoxins in agricultural commodities. Development of control strategies against A. flavus and A. parasiticus, the major aflatoxin-producing species, is dependent upon a basic understanding of their diversity in agricultural ecosystems. This review summarizes our current knowledge of species and population diversity in the United States in relation to morphology, mycotoxin production and genetic characters. The high genetic diversity in populations of aflatoxigenic fungi is a reflection of their versatile habits in nature, which include saprotrophic colonization of plant debris in soil and parasitism of seeds and grain. Genetic variation within populations may originate from a cryptic sexual state. The advent of intensive monoculture agriculture not only increases population size but also may introduce positive selective pressure for aflatoxin production due to its link with pathogenicity in crops. Important goals in population research are to determine how section Flavi diversity in agricultural ecosystems is changing and to measure the direction of this evolution.

Dioctatin A is a strong inhibitor of aflatoxin production by Aspergillus parasiticus

Dioctatin A (DotA), a metabolite of Streptomyces, is known to be an inhibitor of human dipeptidyl aminopeptidase II. Here, it was found that DotA strongly inhibited aflatoxin production by Aspergillus parasiticus, with an IC50 value of 4.0 microM. The mycelial growth of the fungus was not affected by the addition of DotA at a concentration of 50 microM, but inhibition of conidiation was observed at the same concentration. DotA inhibited production of norsolorinic acid, an early biosynthetic intermediate of aflatoxin, and it strongly reduced the mRNA levels of genes encoding aflatoxin biosynthetic enzymes, and significantly decreased the mRNA level of aflR, which encodes a key regulatory protein for aflatoxin biosynthesis. In addition to these genes, the mRNA level of brlA, which encodes a conidiation-specific transcription factor, was also reduced by the addition of DotA. It was also found that DotA dramatically enhanced kojic acid production by the fungus. Furthermore, DotA inhibited production of sterigmatocystin, which is a toxic aflatoxin biosynthetic intermediate, and it also inhibited conidiation in Aspergillus nidulans. These results indicate that DotA has pleiotropic effects on regulatory mechanisms of fungal secondary metabolite production and differentiation, leading to inhibition of aflatoxin production.

Modulation of aflatoxin toxicity and biomarkers by lycopene in F344 rats

Modulation by lycopene of aflatoxin B(1) (AFB(1))-induced toxic effects, metabolism, and metabolic activations was studied in young F344 rats. Animals were pretreated orally with either corn oil (control group) or lycopene [100 mg/kg body weight (b.w.), intervention group] 5 days/week for 2 weeks. Control animals were then treated daily with AFB(1) (250 microg/kg b.w) alone. Intervention animals were administered lycopene (100 mg/kg b.w.) at 1 h following a daily treatment with AFB(1) (250 mug/kg b.w.). Pretreatment and intervention with lycopene significantly reduced the toxic effect caused by AFB(1) and greatly modulated AFB(1) metabolism and metabolic activation. Urinary excretion of AFB(1) phase 1 metabolites, AFM(1), AFQ(1), and AFP(1), was significantly decreased in lycopene-treated animals. Formation of serum AFB(1)-albumin adducts was also significantly reduced. The rate of reduction was from approximately 30% on day 1 (p<0.05) to 67.7% on day 15 (p<0.001). Lycopene intervention also significantly reduced formation of AFB(1)-DNA adducts in liver compared to control animals, with the highest reduction (52.7%) occurring on day 3 (p<0.05). Levels of AFB(1)-N(7)-guanine excreted in urine were also significantly decreased. Urinary excretion of the phase 2 detoxification metabolite, AFB(1)-mecapturic acid, was significantly increased in lycopene-intervened animals. AFB(1)-induced urinary excretion of 8-hydroxydeoxyguanosine was also reduced to 50% on day 7 after lycopene intervention. Collectively, these results suggest that inhibition of phase 1 metabolism and metabolic activation, as well as induction of phase 2 detoxification enzyme activity are the potential mechanisms for the chemopreventive effects of lycopene.

In Vitro and In Vivo Assessment of Humic Acid as an Aflatoxin Binder in Broiler Chickens

The in vitro affinity and adsorption capacity of a humic acid, oxihumate, for aflatoxin B1 (AFB1) was evaluated, utilizing Langmuir and Freundlich adsorption isotherms. Oxihumate showed a high in vitro affinity for AFB1. The Freundlich isotherm fitted the data better than the Langmuir isotherm, and binding capacities of 10.3, 7.4, and 11.9 mg of AFB1/g of oxihumate at pH 3, 5, and 7, respectively, were calculated. The in vivo efficacy of oxihumate as an aflatoxin binder in male broiler chickens exposed to aflatoxin-contaminated feed from 7 to 42 d of age was also assessed. The efficacy of oxihumate was compared with a commercially available product with a brewers dried yeast (BDY) and brewers fermentation solubles as main active ingredients. A total of 420 birds were assigned to 28 pens, with 15 birds per pen. The following treatments were applied: 1) 0 mg of AFB1 + 0 additives, 2) 1 mg of AFB1/kg of feed + 0 additives, 3) 1 mg of AFB1/kg of feed + 3.5 g of oxihumate/kg of feed, 4) 1 mg of AFB1/kg of feed + 3.5 g of BDY/kg of feed, 5) 2 mg of AFB1/kg of feed + 0 additives, 6) 2 mg of AFB1/kg of feed + 3.5 g of oxihumate/kg of feed, and 7) 2 mg of AFB1/kg of feed + 3.5 g of BDY/kg of feed. Each treatment consisted of 4 replicates. Oxihumate was effective in diminishing the adverse effects caused by aflatoxin on BW of broilers (P < 0.05). Oxihumate also showed protective effects against liver damage, stomach and heart enlargement, as well as some of the hematological and serum biochemical changes associated with aflatoxin toxicity (P < 0.05). Results indicated that oxihumate, but not BDY, could alleviate some of the toxic effects of aflatoxin in growing broilers. Oxihumate might, therefore, prove to be beneficial in the management of aflatoxin-contaminated feedstuffs for poultry when used in combination with other mycotoxin management practices. Additional studies are warranted to assess its efficacy under a wide variety of circumstances.

Decontamination of aflatoxin duckling feed with aqueous citric acid treatment

Detoxification of commercial aflatoxin B 1 (AFB 1) contaminated feed by means of 1N aqueous citric acid was confirmed by the AFLATEST™ immunoaffinity column method (IAC), high performance liquid chromatography (HPLC), Ames test ( Salmonella-microsomal screening system), and the 1-day duckling assay. IAC and HPLC determinations showed that AFB 1 at an initial concentration of 110 ng/g was partially detoxified (86%) by the acidic treatment. Results of the Ames test indicated that the mutagenic activity of treated AFB 1 was greatly reduced (or inactivated) compared with that of untreated controls based on his − → his + reversions in the Salmonella TA100 strain. The toxicology and pathology studies showed that toxicity of AFB 1 was minimized by acidic treatment. The results indicated that aqueous citric acid exhibits detoxifying activity in AFB 1-contaminated feeds and protects animals from chronic aflatoxin toxicity.