The toxic effect of aflatoxin B1 on early porcine embryonic development

Abstract

Aflatoxin B1 (AFB1) is a type of mycotoxin produced by the fungi Aspergillus flavus and Aspergillus parasiticus. AFB1 is considered as the most toxic mycotoxin owing to its toxic effect on health. In the present study, the toxic effect of AFB1 on early porcine embryonic development and its possible mechanism were investigated. Blastocyst formation was impaired with treatment of 1 nM AFB1 compared with control, 0.01, 0.1 group (40.13 ± 2.10%, 28.21 ± 1.62%, 32.34 ± 2.07% vs 19.01 ± 1.06%). Further study showed that the presence of AFB1 induced the generation of reactive oxygen species (ROS). And excessive ROS caused DNA damage which confirmed by the comet assay. Additionally, AFB1 also disrupted the DNA damage repair through the regulation of 53BP1. The AFB1 treatment significantly increased the γH2A foci and decreased the 53BP1 foci. TUNEL assay confirmed the generation of apoptosis, further resulting in the occurrence of autophagy. Moreover, AFB1 significantly increased the expression of pro-apoptosis genes Bax and Casp3 and reduced the expression of anti-apoptotic genes Bcl2 and Bcl-xl. In addition, the AFB1 also significantly increased the expression of autophagy related genes Lc3 and Beclin1. The presence of AFB1 significantly impaired the cell proliferation, a parameter of blastocyst quality for outgrowth. These results showed that the presence of AFB1 impaired porcine early embryonic development through oxidative stress, as well as DNA damage and repair, apoptosis, autophagy.