Apoptotic effects on maturation of mouse oocytes, fertilization and fetal development by puerarin

Previously we identified puerarin, an isoflavone compound, as a risk factor for normal embryonic development that triggers apoptotic processes in the inner cell mass of mouse blastocysts, leading to retardation of embryonic development and cell viability. In the current study, we investigated whether puerarin exerts deleterious effects on mouse oocyte maturation, in vitro fertilization (IVF) and subsequent pre- and post-implantation development, both in vitro and in vivo. Notably, puerarin caused significant impairment of these processes in vitro. Pre-incubation of oocytes with puerarin during in vitro maturation led to increased post-implantation embryo resorption and decreased mouse fetal weight. In an in vivo animal model, intravenous injection with or without puerarin (1, 3 and 5 mg/kg body weight/day) for 4 days caused a decrease in oocyte maturation and IVF, and led to deleterious effects on early embryonic development. Importantly, pre-incubation of oocytes with a caspase-3-specific inhibitor effectively blocked puerarin-triggered deleterious effects, clearly implying that embryonic injury induced by puerarin is mediated by a caspase-dependent apoptotic mechanism. These results clearly demonstrate that puerarin has deleterious effects on mouse oocyte maturation, fertilization and subsequent embryonic development in vitro and in vivo.