Aflatoxin Toxicity Reduction in Feed by Enhanced Binding to Surface-Modified Clay Additives

Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (Kd = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (Kd = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (Kd = 13,800) and carnitine (Kd = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (Kd = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (Kd = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (Kd = 1340) or the untreated montmorillonite (Kd = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity

Intervention trial with calcium montmorillonite clay in a south Texas population exposed to aflatoxin

South Texas currently has the highest incidence of hepatocellular carcinoma (HCC) in the United States, a disease that disproportionately affects Latino populations in the region. Aflatoxin B(1) (AFB(1)) is a potent liver carcinogen that has been shown to be present in a variety of foods in the U.S., including corn and corn products. Importantly, it is a dietary risk factor contributing to a higher incidence of HCC in populations frequently consuming AFB(1)-contaminated diets. In a randomized double-blind placebo controlled trial, we evaluated the effects of a three-month administration of ACCS100 (refined calcium montmorillonite clay) on serum AFB(1)-lysine adduct level and serum biochemistry in 234 healthy men and women residing in Bexar and Medina Counties, Texas. Participants recruited from 2012–2014 received either a Placebo, 1.5 g, or 3 g ACCS100 each day for three months, and no treatment during the 4(th) month. Adverse event rates were similar across treatment groups and no significant differences were observed for serum biochemistry and hematology parameters. Differences in levels of AFB(1)-lysine adduct at 1, 3, and 4 months were compared between Placebo and active treatment groups. Although serum AFB(1)-lysine adduct levels were decreased by month 3 for both treatment groups, the Low dose was the only treatment that was significant (p=0.0005). In conclusion, the observed effect in the Low dose treatment group suggests that the use of ACCS100 may be a viable strategy to reduce dietary AFB(1) bioavailability during aflatoxin outbreaks and potentially in populations chronically exposed to this carcinogen

Dietary exposure to aflatoxin and micronutrient status among young children from Guinea

SCOPE: Aflatoxin exposure coincides with micronutrient deficiencies in developing countries. Animal feeding studies have postulated that aflatoxin exposure may be exacerbating micronutrient deficiencies. Evidence available in human subjects is limited and inconsistent. The aim of the study was to investigate the relationship between aflatoxin exposure and micronutrient status among young Guinean children. METHOD AND RESULTS: A total of 305 children (28.8 ± 8.4 months) were recruited at groundnut harvest (rainy season), of which 288 were followed up 6 months later post-harvest (dry season). Blood samples were collected at each visit. Aflatoxin-albumin adduct levels were measured by ELISA. Vitamin A, vitamin E and β-carotene concentrations were measured using HPLC methods. Zinc was measured by atomic absorption spectroscopy. Aflatoxin exposure and micronutrient deficiencies were prevalent in this population and were influenced by season, with levels increasing between harvest and post-harvest. At harvest, children in the highest aflatoxin exposure group, compared to the lowest, were 1.98 (95%CI: 1.00, 3.92) and 3.56 (95%CI: 1.13, 11.15) times more likely to be zinc and vitamin A deficient. CONCLUSION: Although children with high aflatoxin exposure levels were more likely to be zinc and vitamin A deficient, further research is necessary to determine a cause and effect relationship

Adição de bentonita sódica como adsorvente de aflatoxinas em rações de frangos de corte Utilization of sodium bentonite as adsorbent of aflatoxins in broiler feed

A presença de micotoxinas nas matérias-primas, principalmente no milho utilizado para rações para aves, é uma das maiores preocupações atuais devido aos danos causados por essa substâmcia não só aos animais, mas também aos produtores e às empresas do setor avícola. Considerando a utilização de adsorvente ou seqüestrante na ração para minimizar os efeitos deletérios, realizou-se um experimento para avaliar o efeito da adição de um adsorvente, baseado em bentonita sódica, na ração de frangos de corte, a fim de reduzir os efeitos de aflatoxinas. Foram utilizados 960 pintos Cobb de um dia de idade, distribuídos em oito repetições de 20 animais nos tratamentos: T1=sem aflatoxina;T2=3mg kg-1 de aflatoxina;T3=sem aflatoxina+0,5% de bentonita; T4=3mg kg-1 de aflatoxina+0,1% de bentonita; T5=3mg kg-1 de aflatoxina+0,3% de bentonita e T6=3mg kg-1 de aflatoxina+0,5% de bentonita. O consumo alimentar, o peso corporal e a conversão alimentar foram afetados pela presença da toxina na ração. A adição de bentonita sódica na ração sem aflatoxina não causou nenhum efeito depressivo nas aves. Nos tratamentos que continham 3mg kg-1 de aflatoxinas, a adição do adsorvente promoveu um melhor desempenho das aves, sendo que 0,3% de adição de bentonita apresentou melhores resultados.<br>High concentrations of micotoxins in raw materials, mainly in corn used in poultry rations of food, is an important subject of study due to hazardous problems not only to the animals themselves but also to the producer and to the poultry industry due to the reduction of performance by aflatoxins. Taking into account the lack of efficient tecnique for its elimination, from the feed, an adsorbent was added to the diets in order to reduce the effects of aflatoxins. Nine hundred sixty day old Cobb chicks, distributed in 8 replicates of 20 birds per pen the following treatments: T1=No aflatoxin; T2=3mg kg-1 of aflatoxin; T3=no aflatoxin+0.5% of bentonite; T4=3mg kg-1 of aflatoxin+0,1% of bentonite;T5=3mg kg-1 of aflatoxin+0.3% bentonite and T6=3mg kg-1 aflatoxin+ 0.5% of bentonite. Feed intake, body weight and feed conversion were depressed by aflatoxin in the feed. The addition of bentonite to the feed without aflatoxin did not caused negative effecs to the broilers. In treatments carried out with 3mg kg-1 of aflatoxins, the addition of the adsorbent promoted a better performance of the broilers with best results for those receiving 0.3% of bentonite

Effect of the inclusion of adsorbents on Aflatoxin B1 quantification in animal feedstuffs

The extraction efficiency of aflatoxin B1 (AFB1) in cattle feed containing nine adsorbents (ADSs) was investigated using two organic/aqueous solvents composed of methanol/water (80/20 v/v; MeOH) and acetone/water (85/15 v/v; AC). Samples were obtained including a highly AFB1-contaminated (HC) and a low-level AFB1-contaminated (LC) feedstuff (15.33 and 7.57 mu g kg-1, respectively), nine ADSs (four clay minerals; one yeast cell wall-based product; one activated carbon and three commercial ADS products) at two different levels of inclusion (10 and 20 g kg-1). After solvent extraction and immunoaffinity column clean-up, all samples were analysed for AFB1 by high-performance liquid chromatography (HPLC) with fluorescence detection. For each contamination level (HC and LC), the data obtained were analysed using a factorial arrangement in a completely randomized design. Means were compared with the correspondent controls using the Dunnett's test. No statistical difference was found in AFB1 levels of feedstuffs not containing ADSs when extracted with AC or MeOH, even if numerically higher values were obtained with AC. A dose-dependent effect (p 0.01) of ADSs inclusion was observed on AFB1 recoveries that were lower when the higher ADS level (20 g kg-1) was included in the HC and LC feedstuffs. Higher AFB1 recoveries were obtained using AC compared with MeOH, both in HC (75.0% versus 12.0%, respectively) and in LC (84.0% versus 22.8%, respectively) ADSs containing feedstuffs. However, when the activated carbon and the sodium bentonite were included in feeds, lower AFB1 concentrations with respect to control values (p 0.001 and 0.05, respectively) were obtained also using AC