Jurado-Campos Alejandro, Soria-Meneses Pedro Javier, Sánchez-Rubio Francisca, Niza Enrique, Bravo Iván, Alonso-Moreno Carlos, Arenas-Moreira María, García-Álvarez Olga, Soler Ana Josefa, Garde José Julián, Fernández-Santos María Del Rocío
SaBio IREC (CSIC-UCLM-JCCM), Campus Universitario, s/n, 02071 Albacete, Spain.
Servicio de Farmacia Hospitalaria, Complejo Hospitalario Universitario de Albacete, GAI, 02071 Albacete, Spain.
Antioxidants (Basel). 2021 Nov 6;10(11):1780. doi: 10.3390/antiox10111780.
Oxidative stress has become a major concern in the field of spermatology, and one of the possible solutions to this acute problem would be the use of antioxidant protection; however, more studies are required in this field, as highly contradictory results regarding the addition of antioxidants have been obtained. Vitamin E is a powerful biological antioxidant, but its low stability and high hydrophobicity limit its application in spermatology, making the use of organic solvents necessary, which renders spermatozoa practically motionless. Keeping this in mind, we propose the use of hydrogels (HVEs) and nanoemulsions (NVEs), alone or in combination, as carriers for the controlled release of vitamin E, thus, improving its solubility and stability and preventing oxidative stress in sperm cells. Cryopreserved sperm from six stags was thawed and extended to 30 × 10 sperm/mL in Bovine Gamete Medium (BGM). Once aliquoted, the samples were incubated as follows: control, free vitamin E (1 mM), NVEs (9 mM), HVEs (1 mM), and the combination of HVEs and NVEs (H + N), with or without induced oxidative stress (100 µM Fe/ascorbate). The different treatments were analyzed after 0, 2, 5, and 24 h of incubation at 37 °C. Motility (CASA), viability (YO-PRO-1/IP), mitochondrial membrane potential (Mitotracker Deep Red 633), lipid peroxidation (C BODIPY 581/591), intracellular reactive oxygen species production (CM-HDCFDA), and DNA status (SCSA) were assessed. Our results show that the deleterious effects of exogenous oxidative stress were prevented by the vitamin E-loaded carriers proposed, while the kinematic sperm parameters ( ˂ 0.05) and sperm viability were always preserved. Moreover, the vitamin E formulations maintained and preserved mitochondrial activity, prevented sperm lipid peroxidation, and decreased reactive oxygen species (ROS) production ( ˂ 0.05) under oxidative stress conditions. Vitamin E formulations were significantly different as regards the free vitamin E samples ( < 0.001), whose sperm kinematic parameters drastically decreased. This is the first time that vitamin E has been formulated as hydrogels. This new formulation could be highly relevant for sperm physiology preservation, signifying an excellent approach against sperm oxidative damage.
氧化应激已成为男性生殖学领域的一个主要关注点，解决这一紧迫问题的可能方法之一是使用抗氧化保护；然而，由于在添加抗氧化剂方面获得了高度矛盾的结果，该领域还需要更多研究。维生素E是一种强大的生物抗氧化剂，但其低稳定性和高疏水性限制了其在男性生殖学中的应用，使得必须使用有机溶剂，这几乎会使精子失去活力。考虑到这一点，我们提议单独或联合使用水凝胶（HVEs）和纳米乳剂（NVEs）作为维生素E控释的载体，从而提高其溶解度和稳定性，并防止精子细胞中的氧化应激。将来自六只雄鹿的冷冻保存精子解冻，并在牛配子培养基（BGM）中稀释至30×10⁶精子/mL。分装后，样品按以下方式孵育：对照组、游离维生素E（1 mM）、NVEs（9 mM）、HVEs（1 mM）以及HVEs和NVEs的组合（H + N），有或没有诱导氧化应激（100 µM铁/抗坏血酸盐）。在37℃孵育0、2、5和24小时后对不同处理进行分析。评估了活力（CASA）、存活率（YO-PRO-1/IP）、线粒体膜电位（Mitotracker Deep Red 633）、脂质过氧化（C BODIPY 581/591）、细胞内活性氧生成（CM-HDCFDA）和DNA状态（SCSA）。我们的结果表明，所提出的负载维生素E的载体可防止外源性氧化应激的有害影响，同时始终保持精子运动参数（˂0.05）和精子存活率。此外，维生素E制剂在氧化应激条件下维持并保留了线粒体活性，防止了精子脂质过氧化，并降低了活性氧（ROS）生成（˂0.05）。维生素E制剂与游离维生素E样品相比有显著差异（<0.001），游离维生素E样品的精子运动参数急剧下降。这是首次将维生素E制成水凝胶。这种新制剂可能与精子生理保存高度相关，是对抗精子氧化损伤的一种极佳方法。
