Overlapping sperm damages from vitamin B or D deficiency in mice: Insights into the role of clinical supplementations.

In this study, the effect of 14 weeks of standard diet (controls) or folate and vitamin B12-free diet (VBD group) or vitamin D-free diet (VDD group) were assessed on mice testicular function, and sperm function. Vitamin D deprivation caused increased body weight with no effect from VBD confirming the calcium-independent role of vitamin D on body weight homeostasis. The two deprivations caused convergent damages including decreased testosterone, worsened Johnson scores, tubular differentiation index and spermatogenesis index, and serious worsening of sperm parameters and of sperm functional tests (DNA methylation, protamination, DNA damage and lipid peroxidation). From a metabolic point of view, the damage from both models converged on the one carbon cycle (methylations) and the transsulfuration pathway (GSH and antioxidant defences) and increased circulating homocysteine, although with different mechanisms: VBD appeared to hamper methylations due to lower ability to regenerate homocysteine to methionine whereas VDD appeared to interfere with homocysteine transsulfuration to cysteine and, thereafter, GSH. VDD also caused a huge paradox increase of vitamin B12, which was likely in a non-functional form and warrants further investigation. These findings strongly endorse the potential benefit of combined folate/B12 and vitamin D supplementation in infertile patients.

Down-Regulated Expression of Cystathionine ß-Synthase and Cystathionine γ-Lyase in Varicocele, and Infertile Men: A Case-Control Study.

Objective: Cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE) are two important enzymes involved in One-Carbon metabolism. These enzymes play important roles in modulating oxidative stress and inflammation in male factor infertility through participating in the synthesis of glutathione (GSH) antioxidants in the trans-sulfuration pathway. Besides, the direct release of hydrogen sulfide (H2S) has anti-inflammatory and antioxidant effects. Therefore, the expression of CBS and CSE genes at mRNA levels in infertile and varicocele men was evaluated and compared to the healthy counterparts to clarify their possible role in the pathology of male infertility. Materials and Methods: In this case-control study, semen parameter assessment (concentration, morphology, and motility of sperms) was performed on 28 men with varicocele, 43 infertile men with abnormal sperm parameters, and 19 fertile men. RNA was extracted from sperm samples followed by cDNA synthesis and real-time polymerase chain reaction (PCR) using CBS, CSE, and GAPDH primers. Results: Sperm concentration and motility in infertile and varicocele groups were significantly lower (P=0.001), while spermatoza normal morphology was higher than fertile group (P=0.05). The expression levels of both CBS and CSE genes in infertile (P=0.04 and P=0.037 respectively) and varicocele (P=0.01 and P=0.046 respectively) groups were significantly lower than fertile group. Additionally, CBS gene expression indicated a positive correlation with expression of CBS gene (r=0.296, P=0.025) and sperm parameters. Conclusion: In light of our findings, there is a valid rationale to consider the primary role of CBS and CSE enzymes impairment in male factor infertility which specifically may point to a deficit in the release of essential antioxidants including the H2S as a molecular basis of infertility and warrants further investigation.

Micronutrients in Support to The Carbon Cycle Activate Antioxidant Defences and Reduce Sperm DNA Damage in Infertile Men Attending Assisted Reproductive Technology Programs: Clinical Trial Study.

BACKGROUND: Micronutrients in support to the carbon cycle were shown to reduce sperm DNA damage both in animal models and infertile men. Besides supporting DNA methylation, their positive effect may be mediated by an improved performance of the endogenous antioxidant system but this has not yet been proven in clinical settings. The present study aimed at evaluating the effects of micronutrient supplementation in infertile male partners of assisted reproductive technology (ART) resistant couples. MATERIALS AND METHODS: In this experimental clinical trial study, infertile male partners of couples resistant to at least one ART cycle, with a sperm fragmentation rate >20% (TUNEL), underwent a 4-month oral supplementation with micronutrients in support to the carbon cycle including folates, B vitamins, zinc and cysteines. Semen, sperm DNA fragmentation (TUNEL), nuclear maturation (CMA3 and blue aniline staining) and lipid peroxidation (BODIPY) were assessed before and after treatment. The couples were followed-up to record clinical outcomes. RESULTS: Forty-three patients completed the program but full data of pre- and post-treatment were available only for 25 patients. The treatment did not modify sperm concentration or motility but improved morphology. Nuclear maturation, DNA fragmentation and lipid peroxidation significantly improved after the treatment. Overall, 10 clinical pregnancies (23.3%) and 4 live births (9.3%) were recorded during the follow-up following expectant management (25 couples) or a new intracytoplasmic sperm injection (ICSI) cycle (18 couples). CONCLUSION: The micronutrients appeared to induce both DNA methylation, resulting in improved sperm nuclear maturation, and antioxidant defences, resulting in less DNA fragmentation and lipid peroxidation. The clinical outcomes were aligned with a possible positive effect on reproductive function. Micronutrients could be regarded as an alternative to antioxidants in correcting oxidative damage in infertile men; however, to confirm such findings, further clinical investigations are warranted (Registration number: IRCT201510207223N6).