Natural honey acts as a nonpermeating cryoprotectant for promoting bovine oocyte vitrification

Abstract

Sugars are commonly supplemented into vitrification solution to dehydrate cells in order to reduce the formation of fatal intracellular ice crystals. Natural honey is a mixture of 25 sugars (mainly fructose and glucose) that have different biological and pharmacological benefits. The present study was designed to determine if honey can be used as a nonpermeating cryoprotectant in vitrification of bovine oocytes. In the first experiment, denuded-MII oocytes were exposed to 0.25, 0.5, 1.0, 1.5 or 2.0 M of honey or sucrose. Natural honey and sucrose caused similar ooplasm dehydration. A significant relationship existed between time and ooplasm volume change (P < 0.05), during dehydration and rehydration phases, in both honey and sucrose solutions. In the second experiment, the immature cumulus-oocyte complexes (COCs) were vitrified in an EG/DMSO-based vitrification solution containing honey (0.5, 1 or 1.5 M) or sucrose (0.5 M) as a gold standard. The vitrified-warmed COCs were matured in vitro and evaluated for nuclear maturation. The maturation (MII) rate was greater in nonvitrified control (81%) than vitrified groups (54%, P < 0.05). In the third experiment, COCs were either remained nonvitrified (control) or vitrified in 1.0 M honey or 0.5 M sucrose, followed by IVM, IVF and IVC (for 9 days). Cleavage rate was greater in control (74%) than in vitrified groups (47%, P < 0.05), without significant difference between sugars. Blastocyst rate was 34, 13 and 3% in control, honey and sucrose groups respectively (P < 0.05). In conclusion, natural honey acted as a nonpermeating cryoprotectant in vitrification solution and improved the embryonic development in vitrified bovine COCs.

Development of Optimized Vitrification Procedures Using Closed Carrier System to Improve the Survival and Developmental Competence of Vitrified Mouse Oocytes

“…However, increasing the viscosity of the warming solution did not show any positive effects on the survival and embryo development of VW oocytes using the CC in this study ( Figures S1 and S2, Supplementary Materials ). Previous studies have also shown that the survival and cleavage rates are not significantly different between 1.0 M and 0.5 M sucrose solutions in bovine oocytes [ 43 , 44 ]. In contrast, sucrose concentrations higher than 1 M may have detrimental effects on VW oocytes, as observed in mouse ovarian tissues [ 45 ].…”

The Effects of Fructose on the Developmental Competence, Biochemical Biomarkers and Apoptotic Gene Expression by Murine Oocytes

“…Moreover, the higher concentration of fructose in the cultural medium decreases the percentage of degenerated oocytes and increases the percentage of oocyte activation. As noted, the increase of degenerative oocytes is not a desirable sign for the development of embryos in-vitro [15,30]. The fundamental regulator of oocyte metabolism and viability is the percentage of acid metabolism, and maturing oocytes in a media deficient in these regulators causes the oocyte to lose the ability to control its metabolism.…”

The Natural Cryoprotectant Honey for Fertility Cryopreservation

“…A total of 1M concentration of natural non-permeating cryoprotectant honey is suitable for bovine oocyte vitrification, as compared with sucrose. The honey group achieved an improved blastocyst (13%), as compared with sucrose (3%), and can be used in vitrification solution to improve post-warm oocyte viability and embryonic development [27]. Another fertility trial with mouse embryo in 1 Osm/L honey with EG and DMSO (h-VS2) has been conducted by Sarmadia et al (2019).…”

“…Muchlisin et al (2015)) [26], aiming to improve post-thaw semen characteristics. Furthermore, Bilal Alfoteisy et al (2020) used honey in the vitrification solution of cow bovine oocytes to improve post-thaw oocyte viability and embryonic development [27], and Fatemeh Sarmadia et al (2019) reported that the vitrified and warmed mouse embryos with honey-based vitrification solution improved hatching and re-expansion rate of blastocyst [22]. Despite these benefits, more research must be conducted to better understand honey as a natural cryoprotectant in cryopreservation.…”