Conjugated linoleic acid as a potential bioactive molecule to modulates gamete and embryo cryotolerance

Abstract Conjugated linoleic acid (CLA) is a mixture of positional isomers of linoleic acid found in meat and dairy products from ruminants. It is a trans fat widely used by athletes as a food supplement, due to a supposed effect of maximizing the use of body fat reserves. The interest in diet and culture media supplementation with CLA is an emerging area, demanding studies in order to elucidate its benefits in the reproductive parameters, as well as in cryopreservation. Therefore, the aim of this review was to discuss the effects of CLA on the oocytes, sperm and embryos cryotolerance. Some studies have already demonstrated its use in cryopreservation of germline. Among those, it was observed that CLA supplementation during oocyte in vitro maturation can increase their viability post-freezing and developmental capacity. Regarding the use of CLA on sperm, there are few studies and their results are still inconclusive. Finally, studies about CLA supplementation on embryo culture media have shown promising results, indicating that this bioactive molecule is able to modulate lipid uptake on blastomeres. Altogether, these findings demonstrate the potential use of CLA as a bioactive molecule to improve germline and embryo cryotolerance and open new perspectives on human and animal reproduction field.

摘要 共轭亚油酸（Conjugated linoleic acid, CLA）是反刍动物肉类与乳制品中存在的亚油酸位置异构体混合物。作为一种反式脂肪酸，其因被认为可最大化利用体脂储备的功效，被运动员广泛用作食品补充剂。当前，在膳食与培养基中添加CLA的研究正成为新兴领域，亟需开展相关研究以阐明其对生殖参数及冷冻保存的益处。因此，本综述旨在探讨CLA对卵母细胞、精子及胚胎冷冻耐受性的影响。已有多项研究证实其在生殖细胞系冷冻保存中的应用价值。其中研究发现，在卵母细胞体外成熟过程中添加CLA，可提升其冷冻后的存活率与发育能力。关于CLA在精子中的应用，相关研究较少且结果尚不明确。最后，针对胚胎培养基添加CLA的研究已展现出良好前景，表明该生物活性分子能够调控卵裂球的脂质摄取过程。综上，上述研究成果证明CLA作为一种生物活性分子，在改善生殖细胞系与胚胎冷冻耐受性方面具有应用潜力，也为人类与动物生殖领域开辟了全新视角。