Effects of melatonin on in vitro oocyte maturation and embryo development in pigs

Vet World Vol.18 May-2025 Article - 15

Research Article

Veterinary World, 18(5): 1234-1241

https://doi.org/10.14202/vetworld.2025.1234-1241

Laura Andrea Blancas-Alvarez¹

, Alma Lilia Alvarez-Guerrero²

, Alicia Alcantar-Rodriguez¹

, and Alfredo Medrano¹

1. Laboratory of Animal Reproduction (L2), Multidisciplinary Research Unit (UIM), Faculty of Superior Studies, Cuautitlan, National Autonomous University of Mexico, Cuautitlan Izcalli 54714, Mexico.

2. Department of Comparative Biology, Faculty of Sciences, National Autonomous University of Mexico, CDMX 04510 Mexico.

Background and Aim: In vitro fertilization (IVF) efficiency in pigs remains suboptimal, partly due to oxidative stress during oocyte maturation and embryo development. Melatonin (MLT), an endogenous antioxidant, has been proposed as a beneficial supplement in reproductive culture systems. This study aimed to evaluate the effects of different concentrations of MLT on in vitro porcine oocyte maturation and subsequent embryo development.

Materials and Methods: Ovaries were obtained from prepubertal gilts at a local slaughterhouse. A total of 1142 cumulus-oocyte-complexes (COC) were allocated into four groups and matured in vitro with 0, 1, 3, or 5 μM MLT for 44 h. Oocyte maturation was assessed using aceto-orcein staining and viability with trypan blue staining. Subsequently, 1312 COC underwent IVF using a standardized sperm concentration, followed by embryo culture in North Carolina State University-23 medium supplemented with corresponding MLT concentrations for 8 days. Embryo development was classified according to cleavage, morula, and early blastocyst stages. Data were analyzed using analysis of variance with Tukey’s post hoc test (p < 0.05).

Results: Although supplementation with 1.0 μM MLT resulted in the highest metaphase II oocyte maturation rate (45.9% ± 5.70%) and blastocyst formation (26.9% ± 9.57%), no significant differences were observed among treatments in either oocyte maturation, COC viability, or embryo development stages (p > 0.05).

Conclusion: Supplementation with 0–5 μM MLT during oocyte maturation and embryo culture did not significantly enhance in vitro maturation rates or embryonic developmental outcomes in pigs. Further investigations are warranted to optimize MLT concentrations and elucidate its mechanistic role during porcine oocyte and embryo in vitro culture.

Keywords: cumulus-oocyte-complexes, embryo development, in vitro maturation, melatonin, pigs.

How to cite this article: Blancas-Alvarez LA, Alvarez-Guerrero AL, Alcantar-Rodriguez A, and Medrano A (2025) Effects of melatonin on in vitro oocyte maturation and embryo development in pigs, Veterinary World, 18(5): 1234-1241.

Received: 06-01-2025 Accepted: 11-04-2025 Published online: 21-05-2025

Corresponding author: Alfredo Medrano E-mail: amedrano@unam.mx

DOI: 10.14202/vetworld.2025.1234-1241

Copyright: Blancas-Alvarez, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.