Mateus Filipa G, Moreira Silvia, Martins Ana D, Oliveira Pedro F, Alves Marco G, Pereira Maria de Lourdes
Department of Medical Science, University of Aveiro, 3810-193 Aveiro, Portugal.
LAQV-REQUIMTE and Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
J Clin Med. 2023 Sep 6;12(18):5796. doi: 10.3390/jcm12185796.
L-Carnitine, a natural antioxidant found in mammals, plays a crucial role in the transport of long-chain fatty acids across the inner mitochondrial membrane. It is used as a nutritional supplement by professional athletes, improving performance and post-exercise recovery. Additionally, its therapeutic applications, including those in male infertility, have been investigated, as it may act as a defense mechanism against the excessive production of reactive oxygen species (ROS) in the testis, a process that can lead to sperm damage. This effect is achieved by enhancing the expression and activity of enzymes with antioxidant properties. Nevertheless, the mechanisms underlying the benefits of L-Carnitine remain unknown. This review aims to consolidate the current knowledge about the potential benefits of L-Carnitine and its role in male (in)fertility. Considering in vitro studies with Sertoli cells, pre-clinical studies, and investigations involving infertile men, a comprehensive understanding of the effects of L-Carnitine has been established. In vitro studies suggest that L-Carnitine has a direct influence on somatic Sertoli cells, improving the development of germ cells. Overall, evidence supports that L-Carnitine can positively impact male fertility, even at a relatively low dose of 2 g/day. This supplementation enhances sperm parameters, regulates hormone levels, reduces ROS levels, and subsequently improves fertility rates. However, further research is needed to elucidate the underlying mechanisms and establish optimal doses. In conclusion, the role of L-Carnitine in the field of male reproductive health is highlighted, with the potential to improve sperm quality and fertility.
左旋肉碱是一种在哺乳动物体内发现的天然抗氧化剂，在长链脂肪酸穿过线粒体内膜的转运过程中起着至关重要的作用。职业运动员将其用作营养补充剂，以提高运动表现和促进运动后的恢复。此外，人们还对其治疗应用进行了研究，包括在男性不育症方面的应用，因为它可能作为一种防御机制，抵御睾丸中活性氧（ROS）的过量产生，而这一过程可能导致精子损伤。这种作用是通过增强具有抗氧化特性的酶的表达和活性来实现的。然而，左旋肉碱有益作用的潜在机制仍然未知。这篇综述旨在整合目前关于左旋肉碱潜在益处及其在男性生育（或不育）方面作用的知识。通过对支持细胞的体外研究、临床前研究以及对不育男性的调查，已建立了对左旋肉碱作用的全面理解。体外研究表明，左旋肉碱对支持体细胞有直接影响，可改善生殖细胞的发育。总体而言，有证据支持即使每天服用相对低剂量（2克）的左旋肉碱也能对男性生育能力产生积极影响。这种补充剂可改善精子参数、调节激素水平、降低ROS水平，进而提高生育率。然而，需要进一步研究以阐明潜在机制并确定最佳剂量。总之，左旋肉碱在男性生殖健康领域的作用得到了凸显，它具有改善精子质量和生育能力的潜力。
