Silibinin supplementation ameliorates the toxic effects of butyl benzyl phthalate on porcine oocytes by eliminating oxidative stress and autophagy.

Butyl benzyl phthalate (BBP) is a common environmental pollutant, it is high in paints, adhesives and other decorative materials, food packaging bags, cleaning agents, is a plasticizer is very widely used in daily life. However, it remains unknown whether BBP causes damage to oocytes cultured in vitro and whether there is an effective rescue strategy. Here, we evaluated the effects of exposure to different concentrations of BBP (10, 50, and 100 µM) on the meiosis of porcine oocytes. The results showed that exposure to BBP (100 µM) severely impaired expansion of cumulus-oocyte complex (COCs) and PBE (control:71.6% vs 100 µM: 48.8%). Spindle conformation and chromosome alignment were also significantly abnormal (34.8% and 46.0%, respectively) compared to the control (11.1% and 17.5%, respectively), and BBP caused damage to microfilaments and cortical granules (CGs). In addition, oocyte exposure to BBP induced impaired mitochondrial function and disrupted mitochondrial integrity. Silibinin is a natural active substance isolated from the seeds of Silybum marianum (L.) Gaertneri with strong antioxidant and anti-inflammatory effects. Noteworthy, we added different concentrations of silibinin (10, 20, and 50 µM) to BBP-exposed oocytes for rescue experiments, where 50 µM effectively rescued BBP-induced meiotic failure (70.6%). It also prevented the generation of excessive autophagy and apoptosis in oocytes by inhibiting the production of ROS. In a word, our results suggest that supplementation of silibinin attenuates the impaired oocyte development caused by BBP exposure，which provides a potential strategy to protect oocytes from environmental pollutants.

Oxidative stress response associates with the teratogenic effects of benzyl butyl phthalate (BBP).

Benzyl butyl phthalate (BBP) is a persistent environmental pollutant. BBP exposure and the possible effects on human neural tube defects (NTDs) remain elusive. In this study, we found that the detection ratio of positive BBP and its metabolites in maternal urine was obviously higher in NTDs' population than that in normal controls by GC-MS (P < 0.01, P < 0.05, respectively). Animal experiments showed that BBP treatment induced developmental toxicity in chick embryo by enhancing the levels of oxidative stress and cell apoptosis (P < 0.01). More interestingly, the supplement of high-dose choline (CHO, 10 5  µg/mL) could partially restore the teratogenic effects of BBP by inhibiting the occurrence of oxidative stress. Our data collectively suggest that BBP exposure may disturb neural tube development by strengthening oxidative stress. CHO can partially restore the toxicity effects of BBP. This study may provide new insight for NTD prevention.