Effective Detoxification of Aflatoxin B1 and Ochratoxin A Using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study

One of the approaches for reducing exposure to mycotoxins is to lessen their bioavailability by applying nanocomposite adsorbents. Magnetic graphene oxide (MGO) is a new class of nanostructured multifunctional nanocomposite materials, which play a vital role as an adsorbent. The primary aim of this study is to apply response surface methodology (RSM) to optimize the influence of pH within the range of 3 to 7, time (3–7 h), and temperature (30–50 °C), on the simultaneous detoxification of aflatoxin B1 (AFB1) and ochratoxin A (OTA) by using MGO. The optimal condition was obtained at pH 5, 5 h, and 40 °C. Further investigation of the adsorption evaluation was carried out by studying different parameters, such as the influence of contact time, initial mycotoxins concentration, and temperature. According to the experimental data, it can be concluded that the pseudo-second-order kinetic model and the Freundlich isotherm fitted well. The capability of adsorption for the Freundlich model was calculated as 153 and 95 ng/g for AFB1 and OTA, respectively. The thermodynamic study showed that the sorption studies act spontaneously as an exothermic process. These findings suggest that the application of MGO as a nanocomposite is of great significance for the detoxification of mycotoxins.

Substances for reduction of the contamination of feed by mycotoxins: a review

The global occurrence of mycotoxins is considered to be a major risk factor for human and animal health. Contamination of different agricultural commodities with mycotoxins still occurs despite the most strenuous prevention efforts. As a result, mycotoxin contaminated feed can cause serious disorders and diseases in farm animals. A number of approaches, such as physical and chemical detoxification procedures, have been used to counteract mycotoxins. However, only a few of them have practical application. A recent and promising approach to protect animals against the harmful effects of mycotoxin contaminated feed is the use of substances for reduction of the contamination of feed by mycotoxins. These substances, so-called mycotoxin binders (MB), are added to the diet in order to reduce the absorption of mycotoxins from the gastrointestinal tract and their distribution to blood and target organs, thus preventing or reducing mycotoxicosis in livestock. Recently, the use of such substances as technological feed additives has been officially allowed in the European Union. The efficacy of MB appears to depend on the properties of both the binder and the mycotoxin. Depending on their mode of action, these feed additives may act either by binding mycotoxins to their surface (adsorption), or by degrading or transforming them into less toxic metabolites (biotransformation). Biotransformation can be achieved by mycotoxin-degrading enzymes or by microorganisms producing such enzymes. Various inorganic adsorbents, such as hydrated sodium calcium aluminosilicate, zeolites, bentonites, clays, and activated carbons, have been tested and used as MB. An interesting alternative to inorganic adsorbents for the detoxification of mycotoxins is the use of organic binders, such as yeast cell wall components, synthetic polymers (cholestyramine, polyvinylpyrrolidone), humic substances and dietary fibres. This paper gives an overview of the current knowledge and situation in the field of MB. The most important types of MB, mechanism of their action, and their application as a part of general strategy to counteract mycotoxins are described in this review. Recent advances in the use and study of MB, as well as data of their in vitro and in vivo effectiveness are given. Problems, potential, current trends and perspectives associated with the use of MB are discussed as well in the review.

Effect of ochratoxin A on coccidiosis-challenged broiler chicks

A study was conducted to evaluate the effects of ochratoxin A (OTA) on broiler chicks challenged with Eimeria tenella oocysts. Two hundred day-old, unsexed Cobb broiler chicks were randomly divided into four treatment groups. Each treatment consisted of five replicates and ten chicks per replicate, making the following treatments: group I: control; group II: OTA (1 mg/kg) daily through feed; group III: coccidia (orally inoculated with 50,000 E. tenella oocysts/chick on day 21); group IV: OTA (1 mg/kg) daily through feed + coccidia (orally inoculated with 50,000 E. tenella oocysts/chick on day 21). Six birds from each group were slaughtered on the 5th, 7th, 9th and 11th day post infection. The results showed higher mortality with severe gross lesions in caecum and a greater number of faecal oocysts in groups III and IV. The gross lesions observed in group IV were characterised by distension of caecum with blood-tinged content indicative of haemorrhagic typhlitis with mucosal tissue debris. Microscopically, lymphoid organs revealed severe lymphocytolysis and depletion with cellular sparsity in OTA treated groups. The increased severity of lesions in the caecum of group IV was attributed to the additive effect of OTA and E. tenella. Caecum exhibited severe haemorrhages, the presence of numerous second generation schizonts, matured merozoites and developing oocysts. Group IV showed an increase in the severity of coccidiosis which is due to the immunosuppressive effect of OTA. Thus, it was concluded that the expression of E. tenella and its pathological effects were maximum in the presence of OTA compared to the incidence of coccidiosis alone in broiler chicks.