Normal seminal plasma could preserve human spermatozoa against cryopreservation damages in Oligozoospermic patients

Effect of crocin and quercetin supplementation in cryopreservation medium on post-thaw human sperm quality

Biochemical and physical changes during the cryopreservation process adversely affect sperm function required for fertilization. Recently, many studies have been conducted to find effective pre-freezing treatments to limit these damages. The present study aimed to investigate the effects of pre-freezing treatment with quercetin and crocin, individually or in combination, on sperm parameters after thawing procedure. For this, semen samples from 20 normozoospermic men were collected and then each sample was divided into five equal parts: 1. fresh group 2. frozen-thawed group without addition of antioxidants 3. frozen-thawed group containing 1 mM crocin, 4. frozen-thawed group containing 50 μM quercetin, and 5. frozen-thawed group containing a combination of 1 mM crocin and 50 μM quercetin. Pre-cryopreservation and post-thaw sperm motility, morphology, viability, DNA fragmentation, reactive oxygen species [1] (ROS) levels, and mitochondrial membrane potential [2] (MMP) were investigated. Cryopreservation significantly reduced sperm quality. Both crocin and quercetin individually improved sperm progressive motility, decreased ROS levels, reduced DNA fragmentation, and marginally increased MMP, though crocin seems to be more successful in protecting sperm quality. More interestingly, the combined addition of crocin and quercetin to the sperm-freezing medium did not show positive effects on sperm quality. Crocin and quercetin may play a role in mitigating the cryopreservation-induced injury to sperm.

Physiological Benefits of Novel Selenium Delivery via Nanoparticles

Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.

Extend the Survival of Human Sperm In Vitro in Non-Freezing Conditions: Damage Mechanisms, Preservation Technologies, and Clinical Applications

Preservation of human spermatozoa in vitro at normothermia or hypothermia maintaining their functions and fertility for several days plays a significant role in reproductive biology and medicine. However, it is well known that human spermatozoa left in vitro deteriorate over time irreversibly as the consequence of various stresses such as the change of osmolarity, energy deficiency, and oxidative damage, leading to substantial limitations including the need for semen examinations, fertility preservation, and assisted reproductive technology. These problems may be addressed with the aid of non-freezing storage techniques. The main and most effective preservation strategies are the partial or total replacement of seminal plasma with culture medium, named as extenders, and temperature-induced metabolic restriction. Semen extenders consist of buffers, osmolytes, and antioxidants, etc. to protect spermatozoa against the above-mentioned adverse factors. Extended preservation of human spermatozoa in vitro has a negative effect on sperm parameters, whereas its effect on ART outcomes remains inconsistent. The storage duration, temperature, and pre-treatment of semen should be determined according to the aims of preservation. Advanced techniques such as nanotechnology and omics have been introduced and show great potential in the lifespan extension of human sperm. It is certain that more patients will benefit from it in the near future. This review provided an overview of the current knowledge and prospects of prolonged non-freezing storage of human sperm in vitro.