D-Aspartate, a Key Element for the Improvement of Sperm Quality

Abstract

Introduction: D-Aspartate is an endogenous amino acid involved in LH and testosterone release in humans. In this study we investigate the impact of nutritional supplementation of sodium D-aspartate on the improvement of sperm quality in sub-fertile patients and the rate of pregnancies that occurred with their partners. Materials and Methods: A group of 30 patients affected by oligo-asthenozoospermia and a group of 30 patients affected by asthenozoospermia were treated with a daily dose of sodium D-aspartate for 90 days. After which, the change in spermatozoa concentration and their motility and the pregnancies that occurred with their partners were recorded. Results: We found that the supplementation of D-aspartate significantly increased the concentration and the motility of spermatozoa. In oligoasthenozoospermic patients the increase of sperm concentration was found to be 2.0-fold, P < 0.001 (from a mean of 8.2 ± 4.5 million spermatozoa/ml of seminal plasma before treatment to a mean of 16.5 ± 5.5 million after treatment). In asthenozoospermic patients, the increase of spermatozoa was 1.6-fold, P < 0.001 (from a mean of 29.9 ± 5.7 million spermatozoa/ml before treatment to a mean of 48.7 ± 12.8 after treatment). The same positive effects also occurred for sperm motility. Oligo-asthenozoospermic patients showed an increase of rapid progressive spermatozoa motility from a mean of 15.5% ± 4.4% before treatment to a mean of 23.1% ± 4.7% after D-aspartate treatment (1.49-fold increased, P < 0.001). The same effects occurred in oligo-asthenozoospermic patients. In these subjects the increase of rapid progressive spermatozoa motility was 1.86-fold (from 11.6% ± 3.9% before treatment to 21.6 ± 7.5 after treatment, P < 0.001). In addition, the treatment of D-aspartate in these patients consequently led to a significantly increased number of pregnancies occurring in the partners of the treated patients. Conclusions: Treatment of sub-fertile patients with sodium D-aspartate improved the number and the motility of the spermatozoa and consequently improved the rate of pregnancies of their partners.

D-Aspartate amends reproductive performance of aged roosters by changing gene expression and testicular histology

“…Culturing spermatogonial GC-1 cells in DA-containing medium induced both cellular proliferation and survival pathways (Santillo et al 2016). In vivo studies also confirmed the stimulatory effect of DA on sperm concentration, total and forward motility and plasma testosterone concentrations in human (D'Aniello et al 2012) and buck rabbit (Macchia et al 2010).…”

“…D-Aspartic acid (DA) is an endogenous amino acid present in endocrine tissues including the pituitary, adrenal, pineal, ovary and testis (Di Fiore et al 2014). Studies on mammals and seasonal-breeding animals have defined different functions for this unusual amino acid in male reproduction (Raucci et al 2004(Raucci et al , 2014Macchia et al 2010;D'Aniello et al 2012). Both oral and intraperitoneal administration of DA resulted in its accumulation in the rat testis, as well as increased serum LH concentrations and increased testis and serum testosterone levels (Di Fiore et al 2014).…”

“…Although a growing body of evidence points to an effect of DA on male reproduction in several species (Di Fiore et al 1998Raucci et al 2005;Boni et al 2006;Raucci and Di Fiore 2009;Topo et al 2009;D'Aniello et al 2012), the effectiveness of this amino acid on the reproductive fitness in the roosters has not been investigated. Thus, the aim of the present study was to evaluate the effects of orally administered DA on the reproductive performance of aged male broiler breeders.…”

The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review

“…In amphibian testis, the changes of this enzyme are significant, and racemase activity peaks in the reproductive period when D-Asp peaks testosterone levels are the highest during spermatogenesis and reproduction. Thus, D-Asp contributes to the production of more testosterone in the testis (28). Several studies have reported that D-Asp regulates the release and synthesis of testosterone through multiple pathways of the hypothalamic-pituitary-gonadal (HPG) axis (29).…”

D-Amino Acids in the Nervous and Endocrine Systems

“…Upregulated androgen and downregulated estrogen receptor expressions by D-aspartate administration were shown in rat testis [104]. Moreover, the oral intake of D-aspartate induces the release of testosterone in human serum [102] and ameliorates the number and motility of the spermatozoa in humans [105]. Therefore, it is expected that D-aspartate could be a candidate for infertility treatment.…”