The Genotoxicity of Caecal Water in Gilts Exposed to Low Doses of Zearalenone

Abstract

Zearalenone is a toxic low-molecular-weight molecule that is naturally produced by moulds on crops as a secondary metabolite. The aim of this study was to determine the genotoxicity of caecal water collected successively from the caecal contents of gilts exposed to low doses (LOAEL, NOAEL, and MABEL) of zearalenone. The experiment was performed on 60 clinically healthy gilts with average BW of 14.5 ± 2 kg, divided into three experimental groups and a control group. Group ZEN5 were orally administered ZEN at 5 μg/kg BW, group ZEN10—10 μg ZEN/kg BW and group ZEN15—15 µg ZEN/kg BW. Five gilts from every group were euthanized on analytical dates 1, 2, and 3. Caecal water samples for in vitro analysis were collected from the ileocaecal region. The genotoxicity of caecal water was noted, particularly after date 1 in groups ZEN10 and ZEN15 with a decreasing trend. Electrophoresis revealed the presence of numerous comets without tails in groups C and ZEN5 and fewer comets with clearly expressed tails in groups ZEN10 and ZEN15. The distribution of LLC-PK1 cells ranged from 15% to 20% in groups C and ZEN5, and from 30% to 60% in groups ZEN10 and ZEN15. The analysis of caecal water genotoxicity during exposure to very low doses of ZEN revealed the presence of a counter response and a compensatory effect in gilts.

Time-Dependent Changes in the Intestinal Microbiome of Gilts Exposed to Low Zearalenone Doses

“…The above could suggest that high doses of ZEN exert bacteriostatic or bactericidal effects [49], whereas the lowest dose of ZEN has stimulating properties [10]. Similar results were observed in a study evaluating the genotoxicity of caecal water in the same gilts [5] where genotoxic processes of various intensity were noted in groups ZEN10 and ZEN15. Genotoxicity was not reported in group ZEN5.…”

“…The analysed feed did not contain mycotoxins, or its mycotoxin content was below the sensitivity of the method (VBS). The concentrations of modified mycotoxins were not analysed [5,6].…”

“…However, changes in specific tissues or cells were frequently noted in analyses of selected biochemical parameters in samples collected from the same animals and in those animals’ growth performance. The results of these analyses were published in a different paper [5,6].…”

“…Exposure to high doses of mycotoxins, including zearalenone (ZEN), has been well documented [2,3]. However, extensive research conducted in the last decade indicates that health problems resulting from exposure to small doses of the parental compound [4,5,6] without modified mycotoxins [7] can be equally important. The above is confirmed by the hormesis paradigm [7,8].…”

Effects of Mycotoxins on the Intestine

“…Maruo et al [14] concluded that ergot alkaloids that contaminate feed, but at rates under the current EU regulatory limits, still damage the intestine. Likewise, Cieplinska et al [15] reported that the cecal water obtained from pigs fed ZEN at no-observed-adverse-effect-level (NOAEL) and below, still had a significant genotoxic effect, highlighting the need for further investigation into the specific sensitivity of the intestine to mycotoxins.…”