Lycopene Supplementation to Serum-Free Maturation Medium Improves In Vitro Bovine Embryo Development and Quality and Modulates Embryonic Transcriptomic Profile

Abstract

Bovine embryos are typically cultured at reduced oxygen tension to lower the impact of oxidative stress on embryo development. However, oocyte in vitro maturation (IVM) is performed at atmospheric oxygen tension since low oxygen during maturation has a negative impact on oocyte developmental competence. Lycopene, a carotenoid, acts as a powerful antioxidant and may protect the oocyte against oxidative stress during maturation at atmospheric oxygen conditions. Here, we assessed the effect of adding 0.2 μM lycopene (antioxidant), 5 μM menadione (pro-oxidant), and their combination on the generation of reactive oxygen species (ROS) in matured oocytes and the subsequent development, quality, and transcriptome of the blastocysts in a bovine in vitro model. ROS fluorescent intensity in matured oocytes was significantly lower in the lycopene group, and the resulting embryos showed a significantly higher blastocyst rate on day 8 and a lower apoptotic cell ratio than all other groups. Transcriptomic analysis disclosed a total of 296 differentially expressed genes (Benjamini–Hochberg-adjusted p < 0.05 and ≥ 1-log2-fold change) between the lycopene and control groups, where pathways associated with cellular function, metabolism, DNA repair, and anti-apoptosis were upregulated in the lycopene group. Lycopene supplementation to serum-free maturation medium neutralized excess ROS during maturation, enhanced blastocyst development and quality, and modulated the transcriptomic landscape.

Lycopene Reduces the In Vitro Aging Phenotypes of Mouse Oocytes by Improving Their Oxidative Status

“…This finding suggests a role for lycopene in preserving the structural integrity of polyunsaturated fatty acids within oocytes. Consistent with our observations, a better distribution of lipid droplets has been observed in bovine oocytes after lycopene supplementation [ 37 ].…”

“…This may support another study in porcine oocytes that showed a decrease in H 2 O 2 levels, and an increase in GSH concentrations, as well as CAT and SOD expression levels after supplementation of 2.5 μM astaxanthin, a ketocarotenoid with structural similarities to lycopene, during their in vitro aging for 42–44 h [ 57 ]. In addition, in bovine oocytes, lycopene supplementation to the IVM medium led to a significant reduction in ROS levels [ 37 ]. In aged porcine and mouse oocytes, reduced ROS levels have also been reported after melatonin supplementation during their in vitro aging at concentrations of 1 mM and 2 mM, respectively [ 41 , 58 ].…”

“…A stock solution of 1 mM Lycopene (Nawah Scientific Inc., Cairo, Egypt, HIKA2010) was prepared in dimethyl sulfoxide (DMSO; Sigma-Aldrich, D8418), and stored at −20 °C until use. A final concentration of 200 nM was prepared in the maturation medium and used in this study, which was based on previous reports [ 32 , 33 , 37 ].…”

Lycopene supplementation to serum‐free embryo culture medium and its effect on development and quality of bovine blastocysts produced in vitro

“…In a culture medium with lesser ROS, embryos will develop and thrive. Antioxidants act via scavenging ROS, and lycopene is very efficient in doing so as has been shown in earlier studies by our group (Residiwati et al, 2021; Sidi et al, 2022). In vitro production of embryos with higher TCN is essential for a subsequent successful pregnancy.…”

“…Lycopene is a natural carotenoid antioxidant (Bramley, 2000) with potent quench singlet oxygen capacity (Imran et al, 2020). Recent studies showed that lycopene supplementation in the maturation medium improves the development and quality of bovine blastocysts under serum‐free conditions (Residiwati et al, 2021; Sidi et al, 2022). We hypothesize that the antioxidant capacity of lycopene supplementation combined or not with S results in a more efficient reactive oxygen species depletion in the culture medium.…”