deoxynivalenol-3-glucoside and Anorexia

Plants can metabolize the Fusarium mycotoxin deoxynivalenol (DON) by forming the masked mycotoxin deoxynivalenol-3-β-D-glucoside (D3G). D3G might be cleaved during digestion, thus increasing the total DON burden of an individual. Due to a lack of in vivo data, D3G has not been included in the various regulatory limits established for DON so far. The aim of our study was to contribute to the risk assessment of D3G by determination of its metabolism in pigs. Four piglets received water, D3G (116 μg/kg b.w.) and the equimolar amount of DON (75 μg/kg b.w.) by gavage on day 1, 5 and 9 of the experiment, respectively. Additionally, 15.5 μg D3G/kg b.w. were administered intravenously on day 13. Urine and feces were collected for 24 h and analyzed for DON, D3G, deoxynivalenol-3-glucuronide (DON-3-GlcA), deoxynivalenol-15-GlcA (DON-15-GlcA) and deepoxy-deoxynivalenol (DOM-1) by UHPLC-MS/MS. After oral application of DON and D3G, in total 84.8±9.7% and 40.3±8.5% of the given dose were detected in urine, respectively. The majority of orally administered D3G was excreted in form of DON, DON-15-GlcA, DOM-1 and DON-3-GlcA, while urinary D3G accounted for only 2.6±1.4%. In feces, just trace amounts of metabolites were found. Intravenously administered D3G was almost exclusively excreted in unmetabolized form via urine. Data indicate that D3G is nearly completely hydrolyzed in the intestinal tract of pigs, while the toxin seems to be rather stable after systemic absorption. Compared to DON, the oral bioavailability of D3G and its metabolites seems to be reduced by a factor of up to 2, approximately.

Topics: Administration, Oral; Animals; Anorexia; Biological Availability; Biotransformation; Chromatography, High Pressure Liquid; Feces; Glucosides; Indicators and Reagents; Injections, Intravenous; Intestinal Absorption; Male; Mass Spectrometry; Mycotoxins; Reproducibility of Results; Swine; Trichothecenes; Vomiting; Weight Loss

The mycotoxin deoxynivalenol (DON) elicits robust anorectic and emetic effects in several animal species. However, less is known about the potential for naturally occurring and synthetic congeners of this trichothecene to cause analogous responses. Here we tested the hypothesis that alterations in DON structure found in the plant metabolite deoxynivalenol-3-glucoside (D3G) and two pharmacologically active synthetic DON derivatives, EN139528 and EN139544, differentially impact their potential to evoke food refusal and emesis. In a nocturnal mouse food consumption model, oral administration with DON, D3G, EN139528, or EN139544 at doses from 2.5 to 10 mg/kg BW induced anorectic responses that lasted up to 16, 6, 6, and 3 h, respectively. Anorectic potency rank orders were EN139544>DON>EN139528>D3G from 0 to 0.5 h but DON>D3G>EN139528>EN139544 from 0 to 3 h. Oral exposure to each of the four compounds at a common dose (2.5 mg/kg BW) stimulated plasma elevations of the gut satiety peptides cholecystokinin and to a lesser extent, peptide YY3-36 that corresponded to reduced food consumption. In a mink emesis model, oral administration of increasing doses of the congeners differentially induced emesis, causing marked decreases in latency to emesis with corresponding increases in both the duration and number of emetic events. The minimum emetic doses for DON, EN139528, D3G, and EN139544 were 0.05, 0.5, 2, and 5 mg/kg BW, respectively. Taken together, the results suggest that although all three DON congeners elicited anorectic responses that mimicked DON over a narrow dose range, they were markedly less potent than the parent mycotoxin at inducing emesis.

Topics: Animals; Anorexia; Cholecystokinin; Dose-Response Relationship, Drug; Eating; Female; Glucosides; Intestinal Mucosa; Intestines; Mice, Inbred Strains; Mink; Molecular Structure; No-Observed-Adverse-Effect Level; Peptide Fragments; Peptide YY; Trichothecenes; Vomiting