Effects Of Baicalin On In Vitro Maturation And Early Embryonic Development Of Mouse Oocytes

Baicalin has good antioxidant,anti apoptotic and other biological activities.It can reduce the production of reactive oxygen species,inhibit the expression of apoptotic genes and improve the activity of antioxidant enzymes by scavenging free radicals.Because oocytes separated from the maternal environment will be affected by oxidative stress,apoptosis and other factors in the process of in vitro culture,resulting in low in vitro maturation rate and poor subsequent embryo development.In this study,different concentrations of baicalin（0,20,40,60μmol/L）were added to the in vitro maturation（IVM）medium,fertilized in vitro and subsequent embryos were cultured in vitro,GV oocytes were vitrified,and frozen oocytes were cultured and fertilized in vitro.The effects of different concentrations of Baicalin on the in vitro culture environment were discussed,so as to provide a basic theoretical basis and reference for the study of antioxidation in the in vitro culture system and the selection of antioxidants.The results showed that the extrusion rate of the first polar body of the oocytes in 40,60μmol/L baicalin treatment was significantly higher than that of the control group（P<0.05）,and the concentration of SOD,GSH-px and T-AOC in the culture medium of 40μmol/L baicalin treatment was marked higher than that of the control group（P<0.05）,the content of P₄was marked higher than control group.the level of ROS in the cytoplasm of oocytes was dramatically decreased and the content of GSH was increased（P<0.05）,compare to the oocytes in 60μmol/L group,the 40μmol/L group is higher significantly.However,there is no significant effect on the in vitro fertilization rate,cleavage rate and blastocyst rate of mature oocytes between the each treatment（P>0.05）.after vitrification and freezing of GV oocytes,The extrusion rate of the first polar body of the oocytes in 20,40、60μmol/L baicalin group was significantly higher than 0μmol/L baicalin group.Meanwhile the level of ROS in the cytoplasm of oocytes was dramatically decreased and the in vitro fertilization rate,cleavage rate of mature oocytes marked higher than 0μmol/L baicalin group,Compare to other groups,the extrusion rate of polar body of oocytes and the level of ROS in the cytoplasm of oocytes was dramatically decreased in 40μmol/L group.Conclusion:adding 40μmol/L baicalin to the medium of mature in vitro can significantly enhance the activity of antioxidant enzymes,and significantly improve the antioxidant capacity and the extrusion of the first polar body of mouse oocytes matured in vitro,increased the the extrusion rate of the first polar body of the oocytes and dramatically increased the extrusion of the first polar body,fertilization rate and cleavage rate,decreased the level of ROS in the cytoplasm of oocytes of after vitrification and freezing of GV oocytes.