Tri-ortho-cresyl phosphate (TOCP)-induced reproductive toxicity involved in placental apoptosis, autophagy and oxidative stress in pregnant mice.

Tri-ortho-cresyl phosphate (TOCP) has been widely used as plasticizers, and reported causing reproductive toxicity in mammals. However, little is known about the toxic effect on the placenta. In this study, dams were orally administered different doses of TOCP to explore the effect of TOCP on placental development. Results showed that TOCP exposure significantly reduced numbers of implanted embryo, caused atrophy and collapse of ectoplacental cone, and decreased total areas of placenta and numbers of PCNA-positive cells. Expression levels of placental development genes were prominently downregulated in the TOCP-treated groups. Moreover, TOCP administration induced placental apoptosis and autophagy by upregulating P53, Bax, Beclin-1, ratio of LC3 II/LC3 I and Atg5 and downregulating Bcl-2 protein. In addition, TOCP exposure markedly inhibited activities of catalase and superoxide dismutase and increased the production of H2 O2 and malondialdehyde. Collectively, these findings suggest that apoptosis, autophagy and oxidative stress may be involved in the TOCP-induced reproductive toxicity.