The Role of Selected Natural Biomolecules in Sperm Production and Functionality

Abstract

Emerging evidence from in vivo as well as in vitro studies indicates that natural biomolecules may play important roles in the prevention or management of a wide array of chronic diseases. Furthermore, the use of natural compounds in the treatment of male sub- or infertility has been proposed as a potential alternative to conventional therapeutic options. As such, we aimed to evaluate the effects of selected natural biomolecules on the sperm production, structural integrity, and functional activity. At the same time, we reviewed their possible beneficial or adverse effects on male reproductive health. Using relevant keywords, a literature search was performed to collect currently available information regarding molecular mechanisms by which selected natural biomolecules exhibit their biological effects in the context of male reproductive dysfunction. Evidence gathered from clinical trials, in vitro experiments and in vivo studies suggest that the selected natural compounds affect key targets related to sperm mitochondrial metabolism and motion behavior, oxidative stress, inflammation, DNA integrity and cell death. The majority of reports emphasize on ameliorative, stimulating and protective effects of natural biomolecules on the sperm function. Nevertheless, possible adverse and toxic behavior of natural compounds has been indicated as well, pointing out to a possible dose-dependent impact of natural biomolecules on the sperm survival and functionality. As such, further research leading to a deeper understanding of the beneficial or adverse roles of natural compounds is necessary before these can be employed for the management of male reproductive dysfunction.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

“…Infertility is a disease of the male or female reproductive system characterised by the inability to accomplish a pregnancy following at least 12 months of regular unprotected sexual intercourse [ 341 , 342 , 343 ]. According to statistics, 48 million couples and 186 million individuals live with infertility globally [ 341 ], and male factors account for at least 50% of all infertility cases worldwide [ 343 ].…”

“…Infertility is a disease of the male or female reproductive system characterised by the inability to accomplish a pregnancy following at least 12 months of regular unprotected sexual intercourse [ 341 , 342 , 343 ]. According to statistics, 48 million couples and 186 million individuals live with infertility globally [ 341 ], and male factors account for at least 50% of all infertility cases worldwide [ 343 ]. Oxidative stress (OS), which arises from an imbalance between ROS and protective antioxidants, can affect the entire reproductive lifespan of men and women [ 344 ] and has been shown to be a major cause of reproductive dysfunction [ 344 , 345 ].…”

“…Evidence shows that the semen from infertile men has a lower antioxidant capacity and high levels of ROS compared to fertile men [ 345 , 346 ]. As a source of antioxidants, tomato’s constituents and their supplement counterparts may be important for reducing OS and improving semen parameters, including sperm concentration, motility, morphology, and fertility rate [ 341 , 343 , 351 ]. In a human study, tomato soup consumption at 400 g/day significantly increased seminal plasma levels of lycopene, though the effects on plasma antioxidant levels failed to reach significance [ 352 ].…”

“…Research on the polyphenols, flavonoids, and vitamins of tomatoes, including vitamin E, quercetin, and naringenin, indicates that these compounds may also play important roles in the enhancement of semen quality, including sperm concentration, motility, vitality, and structural integrity [ 139 , 341 , 342 , 345 , 349 , 351 , 357 ]. Although other findings are conflicting, according to Aitken et al, at high doses quercetin can have adverse effects on spermatozoa [ 341 , 358 ].…”

Hallmarks of Testicular Aging: The Challenge of Anti-Inflammatory and Antioxidant Therapies Using Natural and/or Pharmacological Compounds to Improve the Physiopathological Status of the Aged Male Gonad

“…Several studies have indicated that common oral antioxidants (e.g., vitamin C, vitamin E, vitamin D, selenium, folate, zine, and carnitine) improve sperm quality (i.e., sperm count, motility, and morphology) both in men and in animal models reviewed by [168,169]. However, these studies have been focused on infertility-related sperm characteristics in young, rather than older, men.…”