Baicalein improves in vitro development rate and quality of preimplantation bovine embryos when supplemented to maturation medium

Abstract EN

Baicalein (5,6,7-trihydroxyflavone) is one of the flavonoid, that is traditionally used in Chinese herbal medicine.

It has an antioxidant properties and acts as free radical scavengers.

However, the effect of baicalein on bovine oocyte maturation and subsequent embryo development is unknown.

For this, good quality bovine oocytes recovered from abattoir ovaries were cultured in IVM medium supplemented with various concentrations of baicalein (0, 0.1, 1.0 and 10 µM) followed by in vitro fertilization and embr yo development.

The cleavage and blastocyst development rates were recorded at days three and eight after fertilization, respectively.

In addition, total cell number and total dead cells (apoptotic) were counted using TUNEL-Hoechst assay.

The results indicate that the proportion of blastocysts derived from oocytes treated with baicalein of 1 µM (38.3%) was greater (P < 0.05) than those of control group (28.7%).

In addition, the percentage of Day - eight blastocysts was not significantly different namong the 0.1 µM (31.5%), 1 µM (38.3%) and 10 µM (32.5%) embryo groups.

The percentage of hatched blastocyst on day eight were significantly higher in the group supplemented with 1 µM (40.5%) baicalein than those in the control and 0.1 µM (33.3% and 32.4, respectively).

Total cell number per blastocyst was increased (P < 0.05) in embryos treated with baicalein at the rate of 1 µM (150.3±5.0) compared with the control group (0 µM) and 10 µM ( 122.9±8.9 and 128.1±6.2, respectively).

However, there were no significant differences between 1 µM (150.3±5.0) and 0.1 µM (139.4±5.7).

Moreover, the number of apoptotic cells was lower (P < 0.05) in blastocysts derived from oocytes treated with baicalein of 1 µM (3.6±0.6) than in control (6.4±1.2) and 10 µM embryos (7.1±1.7).

In conclusion, this study demonstrates that baicalein is a potent antioxidant that improves the maturation environment on the way to promote the developmental competence of bovine oocytes in vitro and increases hatching rate and the total blastocyst cell numbers by suppressing incidence of apoptosis when supplemented at the concentration of 1 µM.