IN VITRO TOXICOLOGICAL EFFECTS OF FUSARIUM MYCOTOXINS ON BOVINE GRANULOSA CELLS

Information on the potential effects of fusariotoxins on reproductive system in ruminants are few. Therefore, the purpose of this study is to evaluate if DON and ZEA major hydroxylated metabolites, α-zearalenol (α-Zol) and β-zearalenone (β-Zol), alone or in combination, can impair bovine reproductive activity via affecting cell proliferation, estradiol (E2) and progesterone (P4) production and gene expression (CYP11A1 and CYP19A1 mRNA abundance) of primary granulosa cells (GC). GC were obtained aspirating aseptically small (1 to 5 mm) (SMGC) and large (8-22 mm) (LGGC) ovarian follicles. GC were cultured for 2 days in medium containing 10% fetal bovine serum followed by 1 or 2 days in serum free medium without (control) or with added treatments. At the end of the experiments, numbers of GC were determined using a Coulter counter, the concentration of steroid hormones was evaluated via radioimmunoassay and RNA analysis was performed. In SMGC cell proliferation was negatively affected after exposure to β-Zol at 31 µM and after exposure to α-Zol (3.1 µM) alone and combined with DON (3.3 µM). Steroidogenesis was differently affected by tested mycotoxins: DON and α-Zol had inhibitory effects while β-Zol at high concentration (31 µM) stimulated steroid production. DON (3.3 µM) and β-Zol (31 µM) increased GC CYP19A1 mRNA abundance. CYP11A1 mRNA abundance was stimulated by DON, alone and combined with α-Zol and β-Zol, whereas was inhibited by β-Zol alone. In LGGC, α-Zol alone and in combination with DON, increased cell proliferation whereas DON strongly inhibited P4 and E2 production mainly at high doses (3.3 µM). In conclusion these results demonstrated that DON and ZEA metabolites may affect in vitro bovine GC function and also provides information on the interaction between DON and ZEA metabolites.