Anethole supplementation during in vitro maturation increases in vitro goat embryo production in a concentration-dependent manner

Abstract

During in vitro maturation (IVM) cumulus-oocyte complexes (COCs) are exposed to conditions that can trigger oxidative stress, thus, reducing oocyte maturation and viability. Aiming to mitigate these detrimental conditions, the effects of IVM medium supplementation with anethole have been tested. Anethole, also known as trans-anethole (1-methoxy-4 [1-propenyl]-benzene), is a naturally occurring phenylpropanoid with various pharmacological properties, including antioxidant effects. However, no study has examined anethole effect on goat COCs during IVM. Thus, the aim of this study was to evaluate the effects of different anethole concentrations on oocyte maturation, oxidative stress, and in vitro development of caprine embryos after parthenogenetic activation. Goat COCs were selected and randomly distributed into the following treatments: TCM-199+ medium (control), or TCM-199+ medium supplemented with 30 μg/mL (AN30); 300 μg/mL (AN300) or 2000 μg/mL (AN2000) of anethole. After IVM, part of the COCs was chosen for oocyte viability and chromatin configuration, intracellular reactive oxygen species levels, and mitochondrial membrane potential assessment. Another part of COCs was parthenogenetically activated, and presumptive zygotes were cultured for 7 days. Results demonstrated that anethole at 30 μg/mL increased oocyte maturation and cleavage rates when compared to the other treatments (P < 0.05), as well as oocyte viability and in vitro embryo production when compared to the control treatment (P < 0.05). Additionally, treatment with anethole at 2000 μg/mL decreased oocyte nuclear maturation and cleavage rates when compared to other treatments (P < 0.05) and embryo production if compared to control and AN30 treatments (P < 0.05). Moreover, anethole at 2000 μg/mL increased mitochondrial membrane potential when compared to the other treatments (P < 0.05). In conclusion, anethole exerts a concentration-dependent effect during goat COCs IVM. For a more desirable outcome of oocyte viability and maturation, and in vitro embryo production, the use of anethole at 30 μg/mL is recommended.