Combined toxic effects of T-2 toxin and propiconazole on the early life stages of zebrafish (Danio rerio)

Background

Agricultural products are frequently co-contaminated by mycotoxins and pesticides. Most studies have only focused on the single toxicities of these chemicals, while their combined effects are neglected. Therefore, we investigated the combined toxic effects of T-2 toxin (T-2) and propiconazole (PRO) on zebrafish (Danio rerio).

Results

Our data exhibited that T-2 had higher toxicity to embryonic fish (96-h LC₅₀ value of 0.39 mg a.i. L⁻¹) than PRO (96-h LC₅₀ value of 17.16 mg a.i. L⁻¹). The mixture of T-2 and PRO showed an acute synergistic effect on zebrafish. Meanwhile, indicators associated with oxidative stress (SOD, Mn-sod, and cat) displayed significant variations in most exposures to T-2 and PRO mixtures (MTP) compared with the single exposures. The expressions of apoptosis-related genes cas3 and cas9 were also substantially elevated in the high-dose MTP exposure compared with the corresponding T-2 exposure. Besides, the expressions of endocrine system-related genes (TRβ, tsh, crh, cyp19a, and vtg1) were markedly varied in most MTP exposures compared with the corresponding single exposures. Our present results suggested that the mixture of T-2 and PRO could cause enormous effects on oxidative stress, cellular apoptosis, and the hypothalamic–pituitary–thyroid/hypothalamic–pituitary–gonadal (HPG/HPT) axis of zebrafish.

Conclusions

Our results provided new insights into the development of combined pollution standards for agricultural products. Taken together, the impact of the combined effects could be considered and regulated as priorities.