Effect of Vitamin E on Oocytes Apoptosis in Nicotine-Treated Mice

Objective(s) Cigarette and nicotine enhances embryogenesis, fertility, pregnancy loss and ultrastructure alterations of oocyte. This study was performed to determine the effect of daily supplementation of vitamin E on oocytes apoptosis in nicotine-treated mice. Materials and Methods In this experimental study, 24 NMARI adult female mice were randomly allocated into four experimental groups. For 30 days, animals in control group (C) were received saline through subcutaneous injection, group I received vitamin E (60 mg/kg/day orally), group II received nicotine (5 mg/kg/day, subcutaneous) and animals of group III received nicotine with vitamin E (60 mg/kg/day orally). After 30 days, the animals were superovulated with PSMG (10 Units) and HCG (10 Units). Next day animals were sacrificed and oocytes were flushed.  Collected oocytes were examined through TUNEL assay for the determination of apoptosis through the use of fluorescent microscope. Results The number of retrieved oocytes was 139, 148, 97 and 127 in control, experimental group I, II and III, respectively. Nicotine treatment increased apoptosis in oocytes up to 13.4% whereas oocytes apoptosis was 3.6% in controls. Supplementation with vitamin E in nicotine-treated mice reduced the oocytes apoptosis to 5.5%. Conclusion This study showed that nicotine exposure (5 mg/kg/day for 30 days) can increase apoptosis in oocytes, and supplementation with vitamin E (60 mg/kg/day orally) can reduce the oocytes apoptosis in nicotine-treated mice.