earticle

영어

In many studies regarding in vitro maturation of mammalian oocytes, flavonoids have been used to improve maturation rate and developmental competence of in vitro-matured oocytes as an one of antioxidants. Myricetin is one of flavonoids that is present in the garlic, tea, and nuts. In human, treatment of myricetin enhanced motility and viability in spermatozoa in vitro. However, study regarding with relation ship betweem myricetin and mammalian oocytes has not been conducted. Therefore, the aim of this study was to investigate the effects of myricetin on the maturation and developmental competence of porcine oocytes. The cumulus-oocyte complexes (COCs) were incubated in IVM medium containing 0, 10, 50, and 100 μg/mL myricetin for 44 h. After 44 h of IVM, oocytes were inseminated with spermatozoa and clevage and blastocyst formation rates were evaluated 48 h and 168 h of IVF, respectively. Nuclear maturation stage was assessed by the aceto-orcein method. For measurement of oxidative stress status, intracellular reactive oxygen species (ROS) and glutathione (GSH) levels were measured using carboxy-DCFDA and cell tracker red, respectively. In results, oocytes in metaphase-II stage was no significant difference between control and myricetin treatment groups. However, treatment of myricetin significantly decreased oocyte population in germinal vesicle (GV) stage (p<0.05), whereas oocytes were arrested in germinal vesicle breakdown (GVBD) stage by myricetin. Intracellular GSH level in oocytes was higher in myricetin treatment groups than control group, but there were no significant difference. On the other hand, intracellular ROS level was not changed among the treatment groups. Interestingly, clevage rate was slightly reduced in 50 μg/mL myricetin treatment group compared with control group. Our findings suggested that treatment of myricetin during in vitro maturation of porcine oocytes could disrupt interaction between nucleic and cytoplasmic maturation. However, more studies regarding with mechanism of this phenomenon are needed.