The effect of selected environmental Fusarium mycotoxins on the ovaries in the female wild boar (Sus scrofa)

Abstract

The contamination of agricultural crops with Fusarium mycotoxins poses one of the greatest problems in food production. Wild boars live in specific habitats and are physiologically sensitive to Fusarium mycotoxins, therefore, they are an interesting model for studies investigating the effects of the discussed toxin, in particular under low-dose exposure. The objective of this study was to determine potential effects of Fusarium mycotoxins ingested with naturally contaminated food on reproductive function based on the proliferation and apoptotic indices of ovarian follicles in female wild boars. The experiment was conducted on 40 wild boars inhabiting north-eastern Poland. The effect of seasonal variations in the quantity and quality of ingested food on the concentrations of Fusarium mycotoxins and their metabolites in the blood of wild boars was analyzed. The observed differences in toxin levels were accompanied by changes in proliferation and apoptotic indices. Proliferation processes were most intense in autumn-winter and were least advanced in winter-spring. The intensity of apoptotic processes was inversely correlated with proliferation.

The Effect of Different Doses of Zearalenone in Feed on the Bioavailability of Zearalenone and Alpha-Zearalenol, and the Concentrations of Estradiol and Testosterone in the Peripheral Blood of Pre-Pubertal Gilts

“…Zearalenone and its metabolite α-zearalenol (α-ZEL) have a similar chemical structure to estrogen, but unlike steroids, they do not originate from sterane structures [6]. Endocrine disruptors, including ZEN, are involved in several mechanisms [7,13] that can influence hormonal systems [14] and produce adverse results, in particular in pubertal gilts: (i) They compete with endogenous estrogens for estrogens receptors (ERs) or androgen receptors (ARs) binding sites, which leads to changes in mRNA expression and protein synthesis and reduces the effectiveness of endogenous steroid hormones, and they are responsible for the transport of ZEN inside cells [6,12,15]; (ii) they can bind with the receptor without activating it, and the presence of a substance on the receptor prevents natural hormone binding (antagonistic effect) [11,16]; (iii) they can bind with blood transport proteins to lower the concentrations of natural hormones in blood [17]; (iv) by disrupting metabolic processes in the body, EDs may affect the degree of synthesis/breakdown and the release of natural hormones [6,18,19].…”

Immunohistochemical Expression (IE) of Oestrogen Receptors in the Intestines of Prepubertal Gilts Exposed to Zearalenone

“…However, histopathological analyses, ultrastructural analyses, and analyses of the metabolic profile of samples taken from same gilts frequently revealed changes in certain tissues or cells. These findings have been posted in various articles [ 2 , 19 , 20 , 31 , 32 , 33 , 34 , 35 ].…”

“…However, they are not steroids and do not originate from sterane structures [ 10 ]. EDs such as zearalenone are involved in several processes [ 11 , 12 ] that influence the endocrine system [ 13 ] and induce side effects [ 14 ]: (i) in prepubertal gilts, EDs compete with endogenous oestrogens for the binding sites of oestrogen receptors (ERs), which can alter mRNA expression levels and protein synthesis and reduce the efficacy of endogenous steroids [ 10 , 15 , 16 , 17 ]; (ii) EDs can bind to the inactive receptor (i.e., blocking it), thereby preventing the binding of natural hormones to that receptor (antagonistic effect) [ 11 , 17 ]; (iii) EDs reduce the levels of circulating natural hormones because they bind to blood transporting proteins, [ 2 ]; and (iv) EDs can also affect the body’s metabolism by influencing the rates of synthesis, decomposition, and release of natural hormones [ 10 , 18 , 19 , 20 ].…”

“…Previous research has demonstrated that the presence of ZEN in feed or food affects the mRNA expression of ERs [ 8 , 24 ] and the activity of other genes encoding metabolic processes in enterocytes [ 25 , 26 ]. Subclinical symptoms of ZEN mycotoxicosis can cause changes in hormonal signalling when enterocytes in different intestinal segments are exposed to this mycotoxin [ 19 ]. The role of zearalenone in the digestive system should be evaluated to determine possible risks for gilts before puberty [ 2 , 27 , 28 , 29 , 30 ].…”

Estrogenic and Non-Estrogenic Disruptor Effect of Zearalenone on Male Reproduction: A Review

“…Endocrine disruptors can disrupt the functioning of the endocrine system even in doses significantly lower than the physiological hormone but, at the same time, they can enter the body in doses significantly higher than the physiological ones. Since some members (hormones) of the endocrine system also act within the system, a defect in the production or binding of a single hormone can affect the entire system [ 69 ].…”