Biotransformation of deoxynivalenol to non-toxic metabolite de-epoxy deoxynivalenol: confirmation by biomarker study in pig serum
Abstract
For more than 30 years scientists have been working on the development of 'biomarkers' to link health effects and exposure to contamination by measuring one crucial parameter in blood or other physiological samples. A number of proven or potential biomarkers for major mycotoxins has been developed in scientific studies (Table 1).
Table 1. Potential biomarkers for the main mycotoxins used in scientific studies.
Source: Biomin, adapted from Baldwin et al., 2011
The European Food Safety Authority (EFSA) sets up rigid parameters for assessment of safety and efficacy of animal feed additives. In order to be registered in EU as substances for reduction of the contamination of feed by mycotoxins, (refers to mycotoxin binder/deactivators in feed industry), mycotoxin/metabolite excretion or relevant biomarkers must be taken as end-points for demonstration of efficacy.
A trial was conducted as a kinetic study to prove the efficacy of Biomin® BBSH 797 to detoxify DON to the non-toxic metabolite de-epoxy-deoxynivalenol (DOM-1) in the gastrointestinal tract of pigs. DON and DOM-1, measured in serum of pigs, are important biomarkers to demonstrate the efficacy of DON deactivating products in vivo.
Trial Design
After an adaption period of two weeks post weaning (ad libitum), 24 weaning piglets (age approx. 6 weeks) were chosen according to weight, gender and overall condition and randomly assigned to three experimental groups with two replicate pens each. Each pen contained two male and two female piglets at an average weight of 14.2 kg. Experimental design is shown in Table 2.
Table 2 – Experimental design
* Source: naturally contaminated wheat
Piglets were accustomed to restrictive feeding for four days during which feed was supplied twice a day. To reach the targeted DON concentration of 2,000 ppb in the experimental diets, naturally contaminated wheat was added in defined amounts. Serum samples of all animals in all groups were taken on day 1, 3 and 4. The blank serum sample was taken before feeding the experimental diets on day 1 (feeding schedule see Table 3).
Table 3 – Feeding schedule
Results
Serum samples were analyzed for DON and DOM-1 concentrations by LC/MS-MS method. Results are displayed in Figure 1 and 2.
Figure 1. DON concentration (ng/ml) in serum of pigs
a, b different letters indicate statistically significant differences (P<0.05)
At the beginning of the trial DON and DOM-1 concentrations in serum were analyzed before feeding the contaminated diets. There were no significant differences among the three groups (see day 1 in Figure 1 and 2). On day 3, DON concentration in serum of the DON group was significantly higher (P<0.05) compared to the control and the DON+BBSH group.
Figure 2. DOM-1 concentration (ng/ml) in serum of pigs
a, b different letters indicate statistically significant differences (P<0.05)
Addition of Biomin® BBSH 797 to DON contaminated feed converted DON into the non-toxic metabolite DOM-1 in the gastrointestinal tract. This resulted in a significant decrease of DON and a significant increase of DOM-1 in serum of the DON+BBSH group, as shown on day 3 in Figure 1 and 2.
Conclusion
Although biomarkers are valuable tools in scientific studies, more knowledge is needed on the factors influencing the bioavailability, kinetics and metabolic profile of mycotoxins in animals before biomarkers could be used in practice on farms.
Acknowledgement
The authors would like to express appreciation to Dr. Franz Berthiller and Dr. Heidi Schwartz-Zimmerman, Christian Doppler Laboratory for Mycotoxin Metabolism, IFA Tulln Austria, for DON and DOM-1 analysis.
*Shu GUAN (guan.shu@biomin.net) is Technical Manager-Mycotoxin with Biomin Singapore Pte Ltd; Simone SCHAUMBERGER and Christina SCHWAB, are Product Managers with Biomin Holding GmbH, Austria. A list of references is available on request to the first author.
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Article made possible through the contribution of Shu GUAN, Simone SCHAUMBERGER, Christina SCHWAB and Biomin
