Lupeol supplementation improves the developmental competence of bovine embryos in vitro

Abstract

Lupeol is a triterpene with various pharmacological properties. This study investigated the effect of lupeol on the in vitro development of bovine embryos. Oocytes (270 per group, 1620 in total) obtained from slaughterhouse-derived ovaries were matured and fertilized in vitro and then cultured for 8 days in a humidified atmosphere of 5% CO2 in air at 38.5 degrees C. The in vitro maturation medium was supplemented with 0.5, 1.0, 2.0, 3.0, and 4.0 mu M lupeol. Treatment with 2.0 mu M lupeol significantly (P < 0.05) improved blastocyst development. Hoechst 33342 staining and terminal deoxynucleotidyl transferase dUTP nick end labeling showed that treatment with 2.0 mu M lupeol improved blastocyst quality by increasing the total cell number and reducing the apoptotic cell number. Confocal microscopy confirmed that treatment with 2.0 mu M lupeol significantly (P < 0.05) reduced the level of 8-oxoguanine, an indicator of reactive oxygen species. Lupeol treatment also significantly attenuated protein expression of nuclear factor-kappa B subunit 1 (NEKB1), cyclooxygenase (COX) 2, and CASP3. Real-time PCR analysis of nitric oxide synthase 2, NFKB1, COX2, CASP3, and BCL2-associated X protein supported the immunofluorescence data. In conclusion, lupeol is a potent antioxidant that improves bovine embryo development in vitro. (C) 2017 Elsevier Inc. All rights reserved.