Influence of mycotoxin zearalenone and its derivatives (alpha and beta zearalenol) on apoptosis and proliferation of cultured granulosa cells from equine ovaries.
BACKGROUND
The mycotoxin zearalenone (ZEA) and its derivatives, alpha and beta-zearalenol (alpha and beta-ZOL), synthesized by genera Fusarium, often occur as contaminants in cereal grains and animal feeds. The importance of ZEA on reproductive disorders is well known in domestic animals species, particularly in swine and cattle. In the horse, limited data are available to date on the influence of dietary exposure to ZEA on reproductive health and on its in vitro effects on reproductive cells. The aim of this study was to evaluate the effects of ZEA and its derivatives, alpha and beta-ZOL, on granulosa cells (GCs) from the ovaries of cycling mares.


METHODS
The cell proliferation was evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test after 3 days exposure at different concentrations of ZEA and its derivatives (from 1 x 10-7 to 0.1 microM). The apoptosis induction was evaluated after 1 day exposure, by DNA analysis using flow cytometry.


RESULTS
An increase in cell proliferation with respect to the control was observed in the presence of ZEA at 1 x 10-3 and 1 x 10-4 microM and apoptosis was induced by all mycotoxins at different concentrations.


CONCLUSIONS
The simultaneous presence of apoptosis and proliferation in GC cultures treated with zearalenones could indicate that these mycotoxins could be effective in inducing follicular atresia. These effects of zearalenones may result from both direct interaction with oestrogen-receptors as well as interaction with the enzymes 3alpha (beta)-hydroxysteroid dehydrogenase (HSD), involved in the synthesis and metabolism of endogenous steroid hormones. These cellular disturbances, described for the first time in equine GCs cultured in vitro, could be hypothesized as referred to reproductive failures of unknown ethiology in the mare.
Minervini
Fiorenza
F
Institute of Sciences of Food Production (ISPA), National Research Council (CNR), Via Amendola 122/O, 70124 Bari, Italy. fiorenza.minervini@ispa.cnr.it
Giannoccaro
Alessandra
A
Fornelli
Francesca
F
Dell'Aquila
Maria Elena
ME
Minoia
Paolo
P
Visconti
Angelo
A
D000821:Animal Feed; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D005496:Follicular Atresia / Q000187:drug effects; D005506:Food Contamination; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects*; D006736:Horses; D015025:Zearalenone / Q000494:pharmacology*; D015029:Zeranol / Q000031:analogs & derivatives* / Q000494:pharmacology
D004968:Estrogens, Non-Steroidal; C029659:zearalenol; D015025:Zearalenone; D015029:Zeranol; D004247:DNA