Testing the protective effects of cyclodextrins vs. alternariol-induced acute toxicity in HeLa cells and in zebrafish embryos

Alternariol (AOH) is a mycotoxin produced by Alternaria fungi, it appears as a contaminant in tomatoes, grains, and grapes. The chronic exposure to AOH may cause carcinogenic and xenoestrogenic effects. Cyclodextrins (CDs) are cyclic oligosaccharides, they form host-guest complexes with apolar molecules. In this study, the interactions of AOH with CD monomers and polymers were examined employing fluorescence spectroscopy. Thereafter, the protective effects of certain CDs vs. AOH-induced toxicity were investigated on HeLa cells and on zebrafish embryos. Our major observations are the following: (1) Sugammadex forms highly stable complex with AOH (K = 4.8 ×10⁴ L/mol). (2) Sugammadex abolished the AOH-induced toxicity in HeLa cells, while native β-CD did not show relevant protective effect. (3) Each CD tested decreased the AOH-induced mortality and sublethal adverse effects in zebrafish embryos: Interestingly, native β-CD showed the strongest protective impact in this model. (4) CD technology may be suitable to relieve AOH-induced toxicity.

Testing the extraction of 12 mycotoxins from aqueous solutions by insoluble beta-cyclodextrin bead polymer

Mycotoxins are toxic metabolites of filamentous fungi; they are common contaminants in numerous foods and beverages. Cyclodextrins are ring-shaped oligosaccharides, which can form host-guest type complexes with certain mycotoxins. Insoluble beta-cyclodextrin bead polymer (BBP) extracted successfully some mycotoxins (e.g., alternariol and zearalenone) from aqueous solutions, including beverages. Therefore, in this study, we aimed to examine the ability of BBP to remove other 12 mycotoxins (including aflatoxin B1, aflatoxin M1, citrinin, dihydrocitrinone, cyclopiazonic acid, deoxynivalenol, ochratoxin A, patulin, sterigmatocystin, zearalanone, α-zearalanol, and β-zearalanol) from different buffers (pH 3.0, 5.0, and 7.0). Our results showed that BBP can effectively extract citrinin, dihydrocitrinone, sterigmatocystin, zearalanone, α-zearalanol, and β-zearalanol at each pH tested. However, for the removal of ochratoxin A, BBP was far the most effective at pH 3.0. Based on these observations, BBP may be a suitable mycotoxin binder to extract certain mycotoxins from aqueous solutions for decontamination and/or for analytical purposes.

Impact of deoxynivalenol on intestinal explants of broiler chickens: An ex vivo model to assess antimycotoxins additives

The impact of deoxynivalenol (DON) upon intestinal tissue of broilers was assessed by using jejunal explants in Ussing chambers and analyzing histopathological and immunohistochemical parameters; this system was also applied to evaluate the efficacy of an antimycotoxins additive (AMA). The explants were subjected to the following treatments within each experiment for 120 min: Experiment 1) T1 (control) - buffer solution, and T2 - 10 mg/L DON; and Experiment 2) T1 (control) - buffer solution, T2 - 10 mg/L DON, T3 - AMA (0.5%), and T4 - 10 mg/L DON + 0.5% AMA. In Experiment 1, DON triggered a reduction in the size of enterocytes as well as of their nuclei, an increase in cytoplasmic vacuolization and apical denudation of villi. Apoptotic cells count was also greater in DON-exposed explants. In Experiment 2, the AMA mitigated DON harmful effects; cytoplasmic vacuolization of enterocytes was reduced and the size of their nuclei was preserved. The additive also promoted a partial decrease in microvillus integrity, in size of enterocytes and in apoptotic cells count. The tested ex vivo model demonstrated the impact of DON upon the intestine as well as the efficacy of the AMA against its damaging effects.

In vitro model to assess the adsorption of oral veterinary drugs to mycotoxin binders in a feed- and aflatoxin B1-containing buffered matrix

Mycotoxin binders are feed additives which are mixed in the feed to adsorb mycotoxins and thereby reducing their toxic effects on animals. Interactions with orally administered veterinary medicinal products, such as antimicrobials or coccidiostats, have been reported previously. This paper describes an in vitro model to screen the interaction between mycotoxin binders and veterinary drugs with respect to the non-specific binding of drugs. It is designed as a static setup using a single concentration of drug and binder in a feed-containing or a feed-plus-mycotoxin-containing matrix, buffered at different pH values. The model was applied to two frequently used antimicrobials in veterinary medicine, doxycycline (DOX) and tylosin (TYL), one major mycotoxin, aflatoxin B1 (AFB1), and four mycotoxin binders. Proportions of feed, DOX or TYL, AFB1, and binder are equivalent to the in vivo situation for broiler chickens, while pH and volume of the buffer are representative of the gastrointestinal tract of chickens. A substantial binding of DOX (~ 88%) and TYL (~ 66%) to the feed-matrix was observed. For the mycotoxin binders, similar results were obtained for DOX and TYL; more specifically up to an inclusion rate of 20 g binder/kg feed, no significant binding was demonstrated, determined as the free concentration of DOX and TYL. A single exception was noticed for TYL and one specific bentonite-based mycotoxin binder, for which no significant interaction could be demonstrated up to 10 g binder/kg but there was an effect at 20 g/kg. In all cases, there was no competition between the tested drugs DOX or TYL and the mycotoxin AFB1 for binding to the bentonite-based mycotoxin binder.

The effects of feed-borne Fusarium mycotoxins and glucomannan in turkey poults based on specific and non-specific parameters

An experiment was conducted to investigate the effects of feeding grains naturally contaminated with Fusarium mycotoxins and a yeast derived glucomannan mycotoxin adsorbent (GMA) on selected specific and non-specific parameters in turkey poults. Two hundred and forty 1-day-old male turkey poults were fed the experimental diets for twelve weeks. Experimental diets were formulated with control grains, control grains+0.2% GMA, naturally-contaminated grains, or naturally-contaminated grains+0.2% GMA. Deoxynivalenol (DON) was the major contaminant of the contaminated grains and concentrations varied from 4.0 to 6.5 mg/kg in the contaminated diets. Non-specific parameters measured included: performance parameters, plasma biochemistry profiles, morphometry and CD8(+) T-lymphocyte counts in the duodenum. Plasma concentrations of DON and de-epoxydeoxynivalenol (DOM-1) were used as specific parameters. Performance parameters and plasma biochemistry were altered by the feeding of contaminated diets and GMA but this was not consistent throughout the trial. The feeding of contaminated diets reduced duodenal villus height and apparent villus surface area. This effect was prevented by GMA supplementation. The feeding of contaminated diets elevated total duodenal CD8(+) T-lymphocyte counts but this effect was not prevented by GMA. No significant differences were seen in plasma concentrations of DON and DOM-1 comparing birds fed contaminated and contaminated+GMA diets suggesting that GMA did not prevent DON absorption under these conditions.