Vitamin B12 and Semen Quality

The preventive and carcinogenic effect of metals on cancer: a systematic review

BACKGROUND

Many studies have investigated the role of metals in various types of malignancies. Considering the wide range of studies conducted in this field and the achievement of different results, the presented systematic review was performed to obtain the results of investigations on the prevention and occurrence of various types of cancer associated with metal exposures.

METHODS

In this review, research was conducted in the three databases: Scopus, PubMed, and Web of Science without historical restrictions until May 31, 2024. Animal studies, books, review articles, conference papers, and letters to the editors were omitted. The special checklist of Joanna Briggs Institute (JBI) was used for the quality assessment of the articles. Finally, the findings were classified according to the effect of the metal as preventive or carcinogenic.

RESULTS

The total number of retrieved articles was 4695, and 71 eligible results were used for further investigation. In most studies, the concentration of toxic metals such as lead (Pb), chromium (Cr (VI)), arsenic (As), cadmium (Cd), and nickel (Ni) in the biological and clinical samples of cancer patients was higher than that of healthy people. In addition, the presence of essential elements, such as selenium (Se), zinc (Zn), iron (Fe), and manganese (Mn) in tolerable low concentrations was revealed to have anti-cancer properties, while exposure to high concentrations has detrimental health effects.

CONCLUSIONS

Metals have carcinogenic effects at high levels of exposure. Taking preventive measures, implementing timely screening, and reducing the emission of metal-associated pollutants can play an effective role in reducing cancer rates around the world.

Machine learning approach to assess the association between anthropometric, metabolic, and nutritional status and semen parameters

Many lifestyle factors, such as nutritional imbalance leading to obesity, metabolic disorders, and nutritional deficiency, have been identified as potential risk factors for male infertility. The aim of this study was to evaluate the relationship between semen parameters and anthropometric, metabolic and nutritional parameters. Relationship was first assessed individually, then after the application of a previously constructed and validated machine learning score that allows their combination. Anthropometric, metabolic, antioxidant, micronutrient, and sperm parameters from 75 men suffering from idiopathic infertility from four infertility centers in France (Jean-Verdier ART Center Hospital, Bondy; North Hospital ART Center, Saint-Étienne; Navarre Polyclinic ART Center, Pau; and Cochin Hospital ART Center, Paris) between September 2009 and December 2013 were collected. After assessing standard correlation analysis, a previously built machine learning model, providing a score ranging from 0 (the poorest) to 1 (the most favorable), was calculated for each man in the study cohort. This machine learning model, which separates infertile/fertile men with unexplained infertility on the basis of their bioclinical signature, provides a more holistic evaluation of the influence of the considered markers (anthropometric, metabolic, and oxidative status). We observed a significant correlation of some anthropometric, metabolic, and nutritional disorders with some sperm characteristics. Moreover, an unfavorable machine learning score was associated with a high level of sperm DNA fragmentation. Favorable anthropometric, metabolic, and oxidative patterns, which may reflect an appropriate lifestyle, appear to positively impact overall health, in particular reproductive function. This study, consistent with previous publications, suggests that beyond semen quality parameters, in an essential assessment of male fertility, other key factors should be taken into account. In this regard, the application of emerging artificial intelligence techniques may provide a unique opportunity to integrate all these parameters and deliver personalized care.

Vitamin B12 Is Associated with Higher Serum Testosterone Concentrations and Improved Androgenic Profiles Among Men with Infertility

BACKGROUND

Infertility impacts 16% of North American couples, with male factor infertility contributing to ∼30% of cases. Reproductive hormones, especially testosterone, are essential for spermatogenesis. An age-independent population-level decline in testosterone concentrations over the past few decades has been proposed to be a consequence of diet and lifestyle changes. Vitamin B12 is present in the testes and has been suggested as an adjuvant nutritional therapy for male infertility due to its potential to improve sperm parameters. However, evidence examining the relationship between vitamin B12 and reproductive hormones is limited.

OBJECTIVES

The objective was to cross-sectionally examine the relationship between serum vitamin B12 and male reproductive hormones (luteinizing hormone, follicular stimulating hormone, total testosterone, estradiol, and prolactin).

METHODS

Men with infertility (n = 303) were recruited from Mount Sinai Hospital in Toronto, Canada. Serum was analyzed for vitamin B12 and reproductive hormones. Statistical analyses included nonparametric Spearman's rank correlation coefficient, linear regression, logistic regression, and effect modification by age and BMI linear regressions.

RESULTS

An independent monotonic relationship between serum vitamin B12 and total testosterone (ρ = 0.19, P = 0.001) was observed. Serum vitamin B12 was linearly associated with total testosterone (unadjusted β = 0.0007, P = 0.008 and adjusted β = 0.0005, P = 0.03). Compared to individuals in the lowest tertile of serum vitamin B12, those in the middle tertile (adjusted odds ratio [OR] = 0.48; 95% confidence interval [CI]: 0.25, 0.93, P = 0.03) and the highest tertile (unadjusted OR = 0.41; 95% CI: 0.22, 0.77, P = 0.005 and adjusted OR = 0.44; 95% CI: 0.22, 0.87, P = 0.02) had reduced odds of testosterone deficiency.

CONCLUSIONS

These findings suggest that among men with infertility, low serum vitamin B12 is associated with a higher risk of testosterone deficiency and impaired androgenic hormonal profiles that impact spermatogenesis and consequently, fertility.

Do Popular Diets Impact Fertility?

Infertility affects 15% of the population in developed countries, and its prevalence is increasing. Fertility can be influenced by different factors. Although key factors like maternal age cannot be changed, there is growing evidence that other modifiable factors, such as diet, can have an impact on fertility. Diet has become increasingly important in recent years for a number of reasons: the new trend toward a healthy lifestyle, the higher prevalence of certain digestive disorders, a lack of time that leads people to consume more prepared and processed food, and personal choice to not eat meat, among others. To meet these needs, several diets have recently become popular, such as the Mediterranean diet, known as the gold standard of health; the DASH diet, known for preventing hypertension; the Western diet, characterized by processed food; the ketogenic diet, characterized by low carbohydrate intake; and the vegetarian diet, which is the choice for people who do not eat meat or animal by-products. Diets present a unique composition characterized by the presence or absence of specific nutrients, which have also been associated with male and female fertility individually. This review assesses the impact of these diets and of macro- and micronutrients on both female and male fertility.

Positive Effects of a Resveratrol-Based Nutraceutical in Association with Surgical Scleroembolization: A Pilot Retrospective Clinical Trial

Background: Varicocele still today represents a common cause of infertility in young men. The treatment strategy remains a surgical approach such as scleroembolization; however, the complete restoration of spermatic parameters afterward requires an average of six or more months to fully regain optimal seminal parameters. Recently, many studies have demonstrated the beneficial effects of Resveratrol in male fertility, given its potential anti-inflammatory, antiapoptotic, and mitochondrial effects. Therefore, Resveratrol-based nutraceuticals could be promising as an adjuvant to mitigate subfertility in patients with varicocele. Methods: In the present study, we retrospectively analyzed the effects of the administration of a Resveratrol-based nutraceutical after the scleroembolization procedure. The improvement of sperm quality in terms of number, motility, and morphology were considered to be the study's main endpoints. A spreadsheet program was used for data analysis, and a p-value of <0.05 was considered significant. Results: We found a statistically significant improvement in the spermatic parameters (sperm count and total motility) and an increase in normal sperm after only 4 months of treatment. The supplementation with a Resveratrol-based nutraceutical associated with the surgical procedure showed encouraging results if compared to data from a control group and the results reported in the literature linked to scleroembolization practice alone. In fact, there was a clear improvement in the seminal parameters at 4 months. Conclusions: This suggests the positive impact of the Resveratrol-based nutraceutical in synergizing with scleroembolization in reducing the time needed to fully recover sperm function.

The Influence of Lifestyle on Male Fertility in the Context of Insulin Resistance-Identification of Factors That Influence Semen Quality

Background: Male fertility is known to have been negatively influenced by the progress of civilization. Another condition whose incidence has been on the increase for the same reason is insulin resistance (IR). In addition, men increasingly often resign from the pursuit of active forms of leisure, preferring more sedentary ones. Considering these trends, this aim of this study was to investigate the relationships between lifestyle factors, insulin resistance, and male fertility in men with and without the condition. A further aim was to select those lifestyle factors that would make it possible to predict the level of male fertility, especially when IR is concerned. Methods: This study was performed in a group of 73 participants, divided into groups based on their insulin resistance status. Their physical activity, diet, perceived stress, sleep quality, libido level, and duration of sexual abstinence were assessed on the basis of a number of parameters, including indices proposed by the authors. In addition, relevant anthropometric measurements were taken and tests related to glucose metabolism and semen quality were carried out. On the basis of these data, statistical tests were performed to establish or disprove relationships between lifestyle choices and semen quality, as measured my sperm motility. Results: The results of this study highlighted the associations between a number of parameters, i.e., micronutrient and vitamin intake, diet quality, body composition, insulin resistance, and the duration of sexual abstinence, and semen quality, as measured by sperm motility. Significantly, the presence or absence of IR was linked to male fertility. A multivariate model was developed, incorporating parameters such as the Matsuda index, vitamin intake, and sexual abstinence duration, to predict motility scores. Conclusions: This study underscores the negative impact of modern civilization's lifestyle choices on male fertility. Notably, vitamin and mineral consumption, especially from antioxidant-rich diets like the Mediterranean diet, emerged as key modifiable factors affecting fertility. Routine diagnostics for insulin resistance in fertility-related interventions is recommended. This study also highlights the importance of considering sexual abstinence duration during semen collection for accurate diagnostic results. Future research should focus on validating the proposed multivariate model and exploring the effects of lifestyle modifications, particularly vitamin supplementation, on fertility outcomes in men, especially in the context of IR.

The effect of red blood cell disorders on male fertility and reproductive health

Male infertility is defined as a failure to conceive after 12 months of unprotected intercourse owing to suspected male reproductive factors. Non-malignant red blood cell disorders are systemic conditions that have been associated with male infertility with varying severity and strength of evidence. Hereditary haemoglobinopathies and bone marrow failure syndromes have been associated with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, and abnormal sperm parameters. Bone marrow transplantation is a potential cure for these conditions, but exposes patients to potentially gonadotoxic chemotherapy and/or radiation that could further impair fertility. Iron imbalance might also reduce male fertility. Thus, disorders of hereditary iron overload can cause iron deposition in tissues that might result in hypogonadism and impaired spermatogenesis, whereas severe iron deficiency can propagate anaemias that decrease gonadotropin release and sperm counts. Reproductive urologists should be included in the comprehensive care of patients with red blood cell disorders, especially when gonadotoxic treatments are being considered, to ensure fertility concerns are appropriately evaluated and managed.

Evaluation of the sperm parameters, oxidative stress, and histopathological effects of vitamin B12 in preventing Helicobacter pylori-induced testicular toxicity: An experimental study

Background

Helicobacter pylori (H. pylori) causes sterility by affecting the reproductive system. Vitamin B12 improves sperm quantity and function.

Objective

Vitamin B12 protection against H. pylori adverse effects was investigated.

Materials and Methods

40 C57 male mice (6 wk) were randomly assigned to 4 equal groups (n = 10) including, group 1 (control without any intervention), group 2 (H), 3 (HP), and 4 (HB) received 1 × 109 colony forming unit (CFU) of H. pylori, 1 × 109 CFU of H. pylori+phosphate buffered saline, 1 × 109 CFU of H. pylori+50 μ g/kg vitamin B  12 intraperitoneally, respectively. In the induction groups, the H. pylori was orogasterically injected 3 times with 1 cc phosphate buffered saline throughout the day. Then testicular metrics, sperm motility, viability, quantity, and shape, plasma levels of malondialdehyde (MDA), superoxide dismutase, glutathione peroxidase, and total antioxidant capacity were measured. Also, testicular-tissue changes were examined using Johnson scores, tubular differentiation index, and spermatogenesis index. Vitamin B12, homocysteine, and testosterone serum levels were examined.

Results

The results showed a significantly lower Johnson score, tubular differentiation index, and spermatogenesis index, and serum level of testosterone and homocysteine as well as a higher MDA level in the H and HP groups than the HB group (p < 0.05). In contrast, the highest superoxide dismutase and glutathione peroxidase enzymes activity and total antioxidant capacity as well as the lowest serum level of MDA were found in the HB group compared to other groups (p < 0.05).

Conclusion

Vitamin B  12 increased antioxidant enzyme activity, enhanced sperm parameters, and decreased injury to testicular tissue. It can be used as a potent antioxidant in reducing testicular damage induced by H. pylori.

The impact of vegetarian diet on sperm quality, sex hormone levels and fertility: a systematic review and meta-analysis

BACKGROUND

An increasing number of people have adhered to a vegetarian diet for several years. Nowadays, the favourable effect of this dietary pattern on metabolic diseases is well established, but its impact on fertility and reproductive health as a serious health concern is not clear yet. Therefore, we aim to summarise existing evidence regarding the possible association between a vegetarian diet and fertility as measured by key indicators such as sperm quality and sex hormone levels.

METHODS

We systematically searched online databases, including PubMed, ISI, Scopus and Google Scholar, up to 1 December 2022 using relevant keywords. We included observational studies that compared semen quality, sex hormone levels and infertility in people who adhered to a vegetarian diet versus an omnivore diet. Heterogeneity between studies was assessed using I2 and Q tests. Standardised mean differences (SMD) using a random/fixed model were calculated to assess outcomes between vegetarians and omnivores in included articles.

RESULTS

Finally, out of 972 documents that were retrieved, 20 articles met our inclusion criteria, and 16 were eligible for quantitative synthesis. Results of meta-analyses showed that there were no significant differences between vegetarians and omnivores in terms of semen quality parameters, including total sperm count, total and progressive sperm motility, sperm morphology and sperm concentration. Seven studies on female sex hormone profiles were eligible for meta-analysis. The only significant difference was the lower level of plasma oestrone in vegetarians (pooled SMD: -0.56; 95% confidence interval [CI]: -1.08, -0.05; p-value = 0.03) compared to omnivores. Furthermore, our meta-analysis revealed significantly higher sex-hormone-binding globulin levels in vegetarian men than in omnivores (pooled SMD: 0.52; 95% CI: 0.18, 0.86; p-value = 0.002).

CONCLUSION

Despite the numerous health benefits of a vegetarian diet, our review suggested that there were no conclusive positive or negative associations between vegetarian diet and semen quality, sex hormone levels and infertility. Further studies are recommended to better understand vegetarian dietary pattern effect on infertility and reproductive health.

Improving the quality of chilled semen from Thai native chicken using phosphorus and vitamin B12 supplementation in semen extender

This study aimed to determine phosphorus and vitamin B12 supplementation effect in semen extender on the quality and fertility ability of chilled Thai native rooster semen. Eighty-four ejaculates of semen from 26 Thai native roosters (Burmese × Vietnam crossbreed) were included. Semen was collected by applying dorsal-abdominal massage once a week, pooled, diluted to 500 million sperms per dose, and divided into 6 groups. The semen samples used for control group were diluted with modified Beltsville poultry semen extender (BPSE). For the treatment groups 2 to 6: semen samples were diluted with modified BPSE and enriched with phosphorus and vitamin B12 (Octafos Octa Memorial Co., Ltd., Bangkok, Thailand) at concentrations 0.02, 0.04, 0.06, 0.08, and 0.10%. Semen fertility ability was tested in 6 replications by inseminating layer hens. Thirty-six Thai native hens were randomly assigned to 3 groups (control, 0.04, and 0.08%) of 12 hens and were inseminated with a dose of 0.2 mL on collecting day. Sperm motion characteristics (i.e., sperm motility, sperm progressive motility, and sperm kinetic parameters) were measured using a computer-assisted sperm analysis system (SCA, Proiser S.L., Valencia, Spain). Sperm viability, mitochondrial activity, acrosome integrity, plasma membrane integrity, and malondialdehyde (MDA) concentration were also evaluated. The sperm motion characteristics were the highest in the 0.04% supplementation group on all days of collection, especially the VCL and VAP (P < 0.05). The viability, mitochondrial activity, plasma membrane and acrosome integrity of spermatozoa were greater in the 0.04% supplementation group than in the control groups (P < 0.05). The 0.04% supplementation group had the lowest MDA concentration in all days of collection. The 0.04% supplementation group were higher both fertility (66.59 vs. 48.50%: P < 0.05) and hatching rates (58.80 vs. 43.18%: P < 0.05) than in the control group. In conclusion, 0.04% phosphorus and vitamin B12 concentrations supplementation in semen extender improved rooster semen quality and fertility in chilled rooster semen.

Supplementing semen extenders with a combination of phosphorus and vitamin B12 Improves post-thawed cryopreserved rooster semen quality

Semen cryopreservation is an important technique for preserving the genetic material of numerous species. However, frozen semen is highly susceptible to sperm DNA damage and reduced motility, resulting in decreased fertility. The standard method for cryopreservation and several approaches have not been elucidated. This study aimed to determine the effects of supplementing rooster semen extender with a combination of phosphorus and vitamin B12 on cryopreserved semen quality. Semen was collected weekly via dorso-abdominal massage from 57 Burmese × Vietnam-crossbred Thai native roosters aged 1-3 years. In total, 139 semen samples were collected, pooled, and diluted to 200 million sperm per dose. The pooled sample was divided into six experimental groups: a control group (0.00%) diluted with modified Beltville Poultry Semen Extender (BPSE) and five treatment groups diluted with modified BPSE supplemented with phosphorus and vitamin B12 at concentrations 0.02, 0.04, 0.06, 0.08, and 0.10%, respectively. The semen samples were frozen and evaluated at 0, 15, and 30 min after thawing. Sperm kinematic parameters were determined using a computer-assisted sperm analysis system. Sperm quality was evaluated by measuring sperm viability, mitochondrial activity, acrosome integrity, and plasma membrane integrity. Statistical analyses were performed using a general linear mixed model (MIXED) in SAS. Factors in the statistical model were experimental groups, time after thawing, and interaction between experimental groups and time after thawing. Total and progressive motilities were greater in semen supplemented with 0.04% phosphorus and vitamin B12 compared with those in the control (p < 0.05). At 15 min post-thawing, VCL, VAP, and HPA in the 0.04% phosphorus and vitamin B12 supplementation group was greater than that in the control (p < 0.05). Phosphorus and vitamin B12 supplementation did not affect sperm kinematics at 0 and 30 min after thawing (p > 0.05). All the sperm parameters that were tested for the 0.04% phosphorus and vitamin B12 supplementation group in modified BPSE were the highest at all the timepoints after thawing. Thus, supplementing frozen semen extender with 0.04% phosphorus and vitamin B12 increased sperm motility, sperm kinematic parameters, and sperm quality.

Oxidative Stress and Male Infertility: The Protective Role of Antioxidants

Oxidative stress is a significant factor in male infertility, compromising sperm function and overall reproductive health. As male infertility garners increasing attention, effective therapeutic interventions become paramount. This review investigates the therapeutic role of antioxidants in addressing male infertility. A detailed examination was conducted on antioxidants such as vitamin C, E, B12, D, coenzyme Q10, zinc, folic acid, selenium, l-carnitine, l-arginine, inositols, and alpha-lipoic acid. This analysis examines the methodologies, outcomes, and constraints of current clinical studies. Antioxidants show notable potential in counteracting the negative effects of oxidative stress on sperm. Based on the evidence, these antioxidants, individually or synergistically, can enhance sperm health and reproductive outcomes. However, certain limitations in the studies call for careful interpretation. Antioxidants are integral in tackling male infertility attributed to oxidative stress. The current findings underscore their therapeutic value, yet there's a pressing need for deeper, comprehensive research. Future studies should focus on refining dosage guidelines, identifying potential side effects, and discerning the most efficacious antioxidant combinations for male infertility solutions.

The relationship of sperm DNA integrity with serum vitamin levels (folate and cobalamin) and food consumption in infertile men

OBJECTIVE

The aim of this study was to investigate the relationships of serum folate (vitamin B9), cobalamin (vitamin B12) levels and diet with semen parameters (semen standard parameters [SSP] and DNA fragmentation index [DFI]) in infertile men.

METHODS

Sperm samples were assessed for SSP and DFI (using the sperm chromatin dispersion test). Serum vitamin concentrations were measured with an immuno-electrochemiluminescence assay, and men completed a semi-quantitative food frequency questionnaire (FFQ).

RESULTS

Serum folate levels were positively correlated with sperm progressive motility and DFI. A comparison of SSP between two groups of patients according to serum folate concentration (B9 <4.840 ng/mL and B9 ≥4.840 ng/mL) showed significantly higher sperm concentration and sperm progressive motility in the latter group. However, there was no difference between these groups regarding DFI. Interestingly, serum folate levels were significantly higher in patients with a high DFI (using the cut-offs of 30% or 18%). FFQ data showed that the consumption of fruits and egg yolk correlated positively with sperm concentration and sperm motility, respectively.

CONCLUSION

Serum folate levels showed significant associations with sperm concentration and sperm progressive motility. However, the positive association of serum folate with DFI raises the need for careful prescription of folate supplements.

The Role of Dietary Nutrients in Male Infertility: A Review

Male infertility is the main health issue with economic, psychological, and medical attributions. Moreover, it is characterized by an inability to produce a sufficient amount of sperm for the fertilization of an oocyte. Dietary nutrients (DN) have a great effect on male reproductive potential. Observations have indicated that adding DN may protect or treat male infertility. The scope of this criticism is to scrutinize the DN, such as omega-3 fatty acids, vitamins, minerals and other phytochemicals, in enhancing the semen attributes, sperm bioenergetics and sperm functionality in male infertility. It seems that diets rich in omega-3 fatty acids affect sperm quality and maintain the sperm membrane and mitochondria stability. An administration of phytochemicals caused an escalation in sperm mitochondrial function and a decrease in oxidative damage. Furthermore, sundry dietary natural phytochemicals differentially affect (negatively or positively) sperm motility, semen quality, and mitochondrial function, dependent on their levels. Vitamins and trace elements are also nutritional modulators in reducing oxidative stress, thereby enhancing sperm quality, which is accurately connected with sperm mitochondrial function. Also, we described the different types of DN as mitochondrial enhancer for sperm functionality and health. We believe that understanding the DN supports sperm mitochondria and epigenetic modulators that may be responsible for sperm quality and health, and will lead to more embattled and efficient therapeutics for male infertility.

Nitrous oxide-induced reproductive risks: Should recreational nitrous oxide users worry?

BACKGROUND

Nitrous oxide (N₂O) is a frequently used anaesthetic. Since the year 2000, recreational use of N₂O, also known as 'laughing gas', became popular as a recreational drug due to its mild psychedelic effect. In the 1980s, several reports warned against N₂O-induced reproductive risks among healthcare personnel, questioning the occupational safety of N₂O in health care.

METHODS

Data about the reproductive risks of N₂O were collected from literature.

RESULTS

Particularly in the past, professionals working in dental and midwifery practices, operating theatres and ambulance transport were exposed to high levels of N₂O. Adverse reproduction effects included congenital anomalies, spontaneous abortion and reduced fertility rates in females. Following occupational measures, like maximal exposure limits for ambient N₂O, this occupational risk was considerably reduced. Recreational users of N₂O, however, voluntarily and repeatedly expose themselves to (very) high doses of N₂O. As such, they exceed the health exposure limits some hundred times, but they are fully unaware of the related reproductive risks.

CONCLUSION

We advocate to increase the awareness in recreational N2O-users about its potential reproductive risks, especially in heavy users, pregnant users or those who intend to become pregnant.

Systematic Review and Critical Analysis on Dietary Supplements for Male Infertility: From a Blend of Ingredients to a Rationale Strategy

Content

Dietary supplements (DS) for male infertility marketed in Italy were evaluated for composition, concentration of ingredients, and recommended daily dose. A systematic review of literature identified ingredients potentially effective on sperm parameters and their minimal effective daily dose (mED).

Objective

This study was conducted in order to critically evaluate the composition and efficacy of DS marketed in Italy.

Design Setting and Participants

This was a systematic review of randomized controlled trials.

Evidence Acquisition

A formula allowed us to classify the expected efficacy of each DS, based on composition. Each DS was scored and included into three classes of expected efficacy: high, low, and none.

Evidence Synthesis

Among 24 supplements, 3 (12.5%) fall in high, 9 (37.5%) in lower, and 12 (50.0%) in no expected efficacy class. DS composition showed 36 substances, 18 with no literature on male fertility and 18 showing positive effect on sperm parameters, thus considered potentially active ingredients (PAI). All DS were mixtures of ingredients, containing from 2 to 17 different substances. Fifteen supplements (65.2%) contained at least 1 ingredient without evidence of efficacy and 21 formulations had PAI dosed below mED. Some PAI were associated to the improvement of specific sperm parameters.

Conclusions

DS were usually blends of many substances that are frequently employed at negligible dose or without any evidence of efficacy on male reproduction. Some ingredients have been demonstrated to be effective on specific sperm parameters by RCTs. We report a list of ingredients with potential efficacy on specific sperm parameters, aimed to allow a tailored use of DS.

Patient Summary

The market of DS for male infertility offers products with potential efficacy in the improvement of sperm parameters but also many with uncertain effects. Based on current scientific literature, our study can help in the choice of DS that are more likely to be effective on specific sperm alterations, so providing the best supplementation for each patient.

Effects of antioxidant co-supplementation therapy on spermatogenesis dysfunction in relation to the basal oxidation-reduction potential levels in spermatozoa: A pilot study

Purpose

In this pilot study, the authors compared the effects of antioxidant co-supplementation therapy and methylcobalamin therapy in patients with impaired semen quality.

Methods

Eighty-four subjects who visited male infertility clinics and showed abnormal semen test results were randomly subjected to one of the two therapies: antioxidant co-supplementation therapy with vitamin C, vitamin E, coenzyme Q10, and flaxseed oil or methylcobalamin therapy. The oxidation-reduction potential (ORP) and 8-hydroxy-2'-deoxyguanosine levels were used as indicators of oxidative stress levels in semen. Semen analysis was also performed.

Results

The authors obtained results from 67 patients who had completed 3 months of treatment. Neither antioxidant co-supplementation therapy nor methylcobalamin therapy changed the semen parameters significantly (except for the sperm concentration, which was increased by the latter therapy). When the pre-treatment ORP value in semen was higher than the cutoff value, both therapies significantly increased the sperm concentration. The 8-hydroxy-2'-deoxyguanosine level did not yield any meaningful predictive value with regard to increased sperm concentrations.

Conclusions

Both antioxidant co-supplementation therapy and methylcobalamin therapy increased the sperm concentration in patients with impaired semen quality when the basal ORP levels in their semen were elevated.

Polybrominated diphenyl ethers and the multi-element profile of house dust in Croatia: Indoor sources, influencing factors of their accumulation and health risk assessment for humans

Given the large amount of time people spend indoors today, human exposure to indoor contaminants causes increasing public health concerns. The present study reports for the first time the levels of 7 polybrominated diphenyl ether (PBDE) congeners, and 18 trace elements measured in dust samples collected in 68 households from Zagreb, Croatia. Based on the obtained data from dust analysis and the questionnaire on the house characteristics and habits of the residents, we aimed to assess the possible indoor sources of PBDEs/elements, and the associated health risks. Mass concentrations of ΣPBDE ranged from 0.16 and 200.09 ng g^-1 dust (median 4.19 ng g^-1 dust). The most frequently detected congeners were BDE-99 and BDE-183 found in >88% of samples, while for trace elements, Al, Fe, Zn, Mn and Cu were found at the highest concentrations (enumerated in the descending order). The regression analysis indicated that renovation, number of residents and hours spent using electronic devices are significant predictors for determining PBDE dust concentrations, while the house age, and the house area were identified as the most important contributors for most trace elements. Our health risk assessment considering dust ingestion and dermal absorption of analyzed dust indicated that no adverse health effects are expected in toddlers and adults from exposure to PBDEs or trace elements in house dust. However, calculating the worst case exposure scenario based on the maximum measured concentrations and high dust intake rates, it was estimated that there is a risk of potential adverse health effects for Co (HI > 1). Even though the cases of high exposure to toxic elements from dust are sporadic, and not common among the general population, this exposure scenario should be included whenever assessing the background exposure of children.

Riboflavin recovery of spermatogenic dysfunction via a dual inhibition of oxidative changes and regulation of the PINK1-mediated pathway in arsenic-injured rat model

Arsenic trioxide (As2O3) poisoning and associated potential lesions are of a global concern. Inversely, riboflavin (vitamin B2, VB2) as a component of flavoproteins could play a vital role in the spermatogenic enzymatic reactions. Thus, this research aimed to explore potential beneficial roles of VB2 during As2O3-injured-toxicity. Rats were randomly allocated into 4 groups (n=8/group) and challenged as follows (for 30 days continuously): Group 1 received normal saline; Group 2 was treated with 3 mg As2O3/L; Group 3 received 40 mg VB2/L; Group 4 received 3 mg As2O3/L + 40 mg VB2/L. Both As2O3 and VB2 were dissolved in deionized water. Malondialdehyde (MDA), Glutathione Peroxidase (GSH-Px), Superoxide dismutase (SOD), and Catalase (CAT) were assessed for the oxidative profile, while TAS (Total Antioxidative Status) levels were evaluated for the antioxidant system, in both serum and testicular tissue. P<0.05 was considered statistically significant. The results show that As2O3 significantly decreased the body weight, testicular weight and testis volume, semen quality and testicular cell count (p<0.05). Furthermore, MDA content in the testicular tissue of the As2O3 group rats was significantly higher in comparison to the vehicle group (p<0.05). Likewise, TAS and the activities of GSH-Px, CAT and SOD were reduced (p<0.05) when compared to the control. As(2)O(3) induced testicular damage and seminiferous tubular atrophy. Monodansylcadaverine assays mirrored the histopathology observations. Meanwhile, As2O3 upregulated the expression of mitophagy-related genes including PINK1, Parkin, USP8, LC3-I, Fis1 and Mfn2. The p38 gene, responsible to stress stimuli, was also upregulated by As2O3 administration. Meanwhile, exposure to VB2 led to a significant decrease of the expression levels of mitophagy related genes. Our study revealed that VB2 supplementation protected testicular structures against As2O3-induced injury via a dual inhibition of oxidative changes and a regulation of the PINK1-mediated pathway.

Vitamin B12 suppresses GADD153, prevents apoptosis and regulates the testicular function in methotrexate treated rat testis

Methotrexate (MTX) is an anti-neoplastic drug that also causes testicular damage. Vitamin B12 (Vit B12) is a water soluble vitamin that is required for normal metabolism. We investigated Vit B12 as a possible protective agent against testicular damage caused by MTX treatment. We divided rats into four groups: control group, Vit B12 group treated with Vit B12 daily for 15 days, MTX group treated with MTX on day 8, MTX + Vit B12 group treated with MTX on day 8 + Vit B12 for 15 days. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone were measured. We also measured proliferating cell nuclear antigen (PCNA), connexin43 (Cx43) and the growth arrest- and DNA damage-inducible gene, 153 (GADD153), using immunohistochemical staining. Apoptosis was assessed using TUNEL staining. The MTX group exhibited degeneration of seminiferous tubules; decreased serum testosterone, LH and FSH levels; fewer PCNA positive cells; increased Cx43 expression; and increased GADD153 and TUNEL stained cells compared to the control group. These pathologic findings were substantially reversed In the MTX + Vit B12 group. MTX caused increased endoplasmic reticulum stress and apoptosis via GADD153. Consequently, Vit B12 potentially is a protective agent against damage caused by MTX.

Can Nutrition Help in the Treatment of Infertility?

Infertility is defined as the inability to conceive after 12 months of unprotected intercourse or six months for women aged 35 years or older. The physical, emotional, psychological, and financial statuses of infertile couples are tremendously affected especially after undergoing diagnostic and/or curative treatments. Human fertility is influenced by multiple factors including female or male, and modifiable or non-modifiable factors. There is growing evidence that nutri-tion may play an important role in adjusting fertility-related outcomes in both men and women. The objective of our study was to summarize the latest data on nutritional factors (specific food groups, nutrients, and nutritional supplements) that have an impact on female or male sexual and reproductive function. PubMed and Google Scholar platforms were used to collect appropriate articles for the review using several combinations of keywords (infertility, diet, dietary supplements, antioxidants, and beverages). Adherence to a healthy dietary pattern favoring fish, poultry, whole grains, fruits, vegetables, and healthy fats, was related to better fertility in both genders. Despite the multifactorial etiology of sexual infertility, nutrition may affect the sexual/reproductive function in both women and men.

Current Nanocarrier Strategies Improve Vitamin B12 Pharmacokinetics, Ameliorate Patients' Lives, and Reduce Costs

Vitamin B12 (VitB12) is a naturally occurring compound produced by microorganisms and an essential nutrient for humans. Several papers highlight the role of VitB12 deficiency in bone and heart health, depression, memory performance, fertility, embryo development, and cancer, while VitB12 treatment is crucial for survival in inborn errors of VitB12 metabolism. VitB12 is administrated through intramuscular injection, thus impacting the patients’ lifestyle, although it is known that oral administration may meet the specific requirement even in the case of malabsorption. Furthermore, the high-dose injection of VitB12 does not ensure a constant dosage, while the oral route allows only 1.2% of the vitamin to be absorbed in human beings. Nanocarriers are promising nanotechnology that can enable therapies to be improved, reducing side effects. Today, nanocarrier strategies applied at VitB12 delivery are at the initial phase and aim to simplify administration, reduce costs, improve pharmacokinetics, and ameliorate the quality of patients’ lives. The safety of nanotechnologies is still under investigation and few treatments involving nanocarriers have been approved, so far. Here, we highlight the role of VitB12 in human metabolism and diseases, and the issues linked to its molecule properties, and discuss how nanocarriers can improve the therapy and supplementation of the vitamin and reduce possible side effects and limits.

Nutrition, genetic variation and male fertility

Infertility affects nearly 50 million couples worldwide, with 40-50% of cases having a male factor component. It is well established that nutritional status impacts reproductive development, health and function, although the exact mechanisms have not been fully elucidated. Genetic variation that affects nutrient metabolism may impact fertility through nutrigenetic mechanisms. This review summarizes current knowledge on the role of several dietary components (vitamins A, B₁₂, C, D, E, folate, betaine, choline, calcium, iron, caffeine, fiber, sugar, dietary fat, and gluten) in male reproductive health. Evidence of gene-nutrient interactions and their potential effect on fertility is also examined. Understanding the relationship between genetic variation, nutrition and male fertility is key to developing personalized, DNA-based dietary recommendations to enhance the fertility of men who have difficulty conceiving.

Estimation of folic acid/micro nutrients levels; Does it reflect sperm parameters

OBJECTIVE

To study the impact of vitamin B12, folic acid (FA) and methylmalonic acid (MMA) on sperm parameters; count, motility and morphology leading to male fertility.

METHODS

The cross-sectional study comprised of one hundred and eighty-six subjects with normal sperm parameters (fertile) and 88 subjects with abnormal sperm parameters labelled as "infertile" from a sample population of Karachi, Pakistan. Vitamin B12, FA and MMA levels in serum were analysed by enzyme linked immune sorbent assay. Unadjusted and adjusted prevalence ratio with their 95% CI were reported by using cox regression algorithm to assess the association of Vitamin B12, FA and MMA and other factors with male Infertility. Unadjusted and adjusted beta coefficients with 95% CI were reported by using linear regression analysis for assessing relationship of Vitamin B12, FA and MMA and other factors with semen parameters (count, motility and morphology); P value of <.05 was considered significant.

RESULTS

It was declared that with every 1 unit increase in vitamin B12, FA and MMA the prevalence of infertility was decreased by 1%, 17% and 74%, respectively. Multivariate analysis revealed that vitamin B12, FA and MMA had a significant association with total sperm count, motility and morphology. The sperm parameters were also affected by increase in; LH, BMI and body fat %. There was a significant positive correlation of; LH with Vitamin B12 and FA (0.423 < 0.001, 0.338 < 0.001) and testosterone with vitamin B12 and FA (0.326 < 0.001, 0.291 < 0.001), respectively.

CONCLUSION

All the studied micronutrients; Vitamin B12, FA and MMA had a positive effect on sperm parameters; count, motility and morphology and the associated reproductive hormones which explains their role on reproductive functions required to acquire fertility.

Is low-level metal exposure related to testicular cancer?

Disruption of element homeostasis may contribute to increased susceptibility of men to cancer development. Whether environmental low-level metal exposure could contribute to the pathogenesis of testicular cancer is unknown. Comparison of the level of 18 elements in whole blood, serum and urine and parameters of oxidative stress/antioxidant status between men with testicular germ cell tumors (TGCT) and healthy men showed significant difference between the groups in most parameters. The results of linear discriminant analysis with a discrimination rate of 96% indicated whole blood Ca, Co, Cu, Fe, K, Mg, Na and Zn, serum Ca, Cu, Na and Ni, and urine Cd, Co, Fe and Mn being the strongest predictors of illness. TGCT patients had a significant increase in serum and blood Cu and decrease in serum Fe and blood Zn with cancer progression. Significantly higher concentrations of Al, As, Pb, and Ni in whole blood/serum of men with TGCT confirm the hypothesis that low-level environmental exposure to these elements may contribute to cancer development. Relationship between elements concentrations and treatment outcomes should be carefully monitored during cancer treatment since high concentrations of commonly used platinum-based chemotherapeutics may additionally disturb the homeostasis of elements.

The effect of vitamin B12 supplement on post-thaw motility, viability and DNA damage of human sperm

Sperm cryopreservation may lead to adverse effects on sperm structure and function. Cyanocobalamin (vitamin B12) has antioxidant potential and can protect DNA from free radical-induced damages. Recent studies have shown that vitamin B12 preserves glutathione that leads to modulate oxidative stress responses. Also, vitamin B12 might act directly as a scavenger of ROS. The aim of this study was to investigate the effects of vitamin B12 supplementation on human sperm parameters during the cryopreservation process. Thirty semen samples were obtained from normozoospermic men. Using cryopreservation medium supplemented with different concentrations of vitamin B12 (0, 0.5, 1, 2, 2.5 mg/ml), the semen samples were cryopreserved. After thawing, all samples were evaluated for motility and viability. Based on results, 2 mg/ml was considered as the optimal concentration of vitamin B12 for evaluating sperm DNA fragmentation. The results showed that 1 and 2 mg/ml vitamin B12 significantly increased post-thawing motility and viability compared with the 0 mg/ml vitamin B12 (p < .05). Also, by supplementing with 2 mg/ml vitamin B12, DNA fragmentation decreased when compared to the control. The present study showed that cryopreservation medium supplemented with vitamin B12 at 2 mg/ml could improve sperm quality after freeze-thaw process.

Dietary supplements in the management of varicocele-induced infertility: A review of potential mechanisms

Varicocele is a main cause of lower production of spermatozoon and infertility with multiple pathophysiological mechanisms. In the past decades, the use of dietary supplements has significantly increased due to both the modern lifestyle and the food shortages of the industrialised countries. The purpose of this review paper is to collect scientific evidences from basic and clinical studies which support the use of dietary supplements to define the clinical framework for patients with varicocele. In the present review, we used keywords such as dietary supplements, varicocele, male infertility, oxidative stress, DNA fragmentation, sperm parameters to find the proper articles. The standard search biomedical engines were used for seeking the papers. The use of dietary supplements such as minerals, vitamins and antioxidants has an essential role in the prevention and treatment of varicocele by increasing the levels of antioxidant enzymes (e.g. peroxidase, superoxide dismutase and catalase) and decreasing the levels of inflammatory markers (e.g. tumour necrosis factor-α, interleukin-6 and interleukin-1) in testis. According to the results, the dietary supplements may alleviate the spermatogenesis in varicocele patients through different mechanisms such as suppression of stress oxidative and inflammation in testicular tissue.

Dietary Supplements for Male Infertility: A Critical Evaluation of Their Composition

Dietary supplements (DS) represent a possible approach to improve sperm parameters and male fertility. A wide range of DS containing different nutrients is now available. Although many authors demonstrated benefits from some nutrients in the improvement of sperm parameters, their real effectiveness is still under debate. The aim of this study was to critically review the composition of DS using the Italian market as a sample. Active ingredients and their minimal effective daily dose (mED) on sperm parameters were identified through a literature search. Thereafter, we created a formula to classify the expected efficacy of each DS. Considering active ingredients, their concentration and the recommended daily dose, DS were scored into three classes of expected efficacy: higher, lower and none. Twenty-one DS were identified. Most of them had a large number of ingredients, frequently at doses below mED or with undemonstrated efficacy. Zinc was the most common ingredient of DS (70% of products), followed by selenium, arginine, coenzyme Q and folic acid. By applying our scoring system, 9.5% of DS fell in a higher class, 71.4% in a lower class and 19.1% in the class with no expected efficacy. DS marketed in Italy for male infertility frequently includes effective ingredients but also a large number of substances at insufficient doses or with no reported efficacy. Manufacturers and physicians should better consider the scientific evidence on effective ingredients and their doses before formulating and prescribing these products.

Seminal plasma vitamin B6 levels in men with asthenozoospermia and men with normal sperm motility, a measurement using liquid chromatography with tandem mass spectrometry

There is growing evidence that vitamin B₆ has a valuable contribution in maintaining normal sperm parameters; however, this contribution has not yet well-identified. Here, we aimed to measure the level of seminal plasma vitamin B₆ in men with asthenozoospermia compared to men with normal sperm motility. Ninety-seven human males with asthenozoospermia and eighty-eight human males with normal sperm motility (control) were recruited in this study. Collected semen samples were assessed for sperm motility, sperm count and semen volume. Liquid chromatography with tandem mass spectrometry was used to measure seminal plasma vitamin B₆ concentrations. A highly significant difference (p < .0001) in concentrations of seminal plasma vitamin B₆ was found between asthenozoospermic and control groups. Besides, no statistical correlations were found between seminal plasma vitamin B₆ level and sperm motility, sperm count, semen volume and men age in both tested groups. In conclusion, men with asthenozoospermia have lower seminal plasma vitamin B₆ level compared to men with normal sperm motility. Also, seminal plasma vitamin B₆ was found not to be correlated with sperm motility and count, semen volume and men age in both tested groups. These results may provide new contribution in the management of male infertility.

Combination therapy with antioxidants improves total motile sperm counts: A Preliminary Study

PURPOSE

Optimal strategies to treat idiopathic male infertility have remained unclear. The aim of this study was to evaluate the effectiveness of combination antioxidant therapy with several vitamins and supplements on semen parameters.

METHODS

Thirty-one men with oligozoospermia and/or asthenozoospermia evaluated by a Makler counting chamber were randomly assigned to two treatment groups: a combination of antioxidant supplements (L-carnitine, zinc, astaxanthin, coenzyme Q10, vitamin C, vitamin B12, and vitamin E) and a Chinese herbal medicine, hochu-ekki-to (HE). Serum endocrinological profiles and semen parameters, especially total motile sperm count, were compared between before and after 12 weeks of treatment in both groups.

RESULTS

In the supplement group, endocrinological findings were not significantly improved. The semen parameters of semen volume, sperm concentration, and sperm motility were not statistically significantly improved, whereas total motile sperm count was significantly improved. In contrast, none of the endocrinological factors or semen findings were significantly improved by the Chinese herbal medicine although semen concentration, semen motility, and total motile sperm count showed a tendency to increase.

CONCLUSION

Because combination antioxidant therapy could improve sperm motility significantly for patients with idiopathic oligoasthenozoospermia, our supplement could be one treatment option for idiopathic male infertility.

The effect of vitamin E & vitamin B on sperm function in rat varicocele model

We assessed the effect of vitamin E and vitamin B (Vit E & Vit B) and their combination on sperm functional parameters in the rat varicocele model. Male rats (n = 120) were divided into control (n = 30), sham (n = 30) and varicocele induction (n = 60) groups. After 2 months, 10 rats from each group were sacrificed to verify varicocele model. This part of results showed that sperm parameters, DNA damage, lipid peroxidation and residual histone were adversely effected in the varicocele group. From the 50 remaining rats in varicocele group, 10 rats received Vit B complex (6, 9.6, 30.4, 9.6 and 0.006 mg/kg for B6, B2, B9, B1 and B12 respectively), 10 rats received Vit E (40 mg/kg), 10 rats received Vit B & E, 10 rats only received water and 10 rats were only received sesame oil as a solvent for Vit E, for 2 months. From 40 remaining rats in control and sham groups, 20 rats only received water and other 20 rats only received sesame oil for 2 months. Then, all the aforementioned parameters were assessed. These results showed that Vit B antioxidant was more efficient in improvement of sperm parameters, chromatin integrity and lipid peroxidation in varicocelized rats compared with Vit E.

Improvement of vitamin B12 status with Spirulina supplementation in Wistar rats validated through functional and circulatory markers

Spirulina evaluated as a source of vitamin B₁₂ through the modulation of vitamin B₁₂ deficiency mediated physiological and biochemical changes in experimental animals. The B₁₂ deficient male weanling Wistar rats were fed with Spirulina-supplemented diet for 10 weeks. An increase in urinary methylmalonic acid (22.70 ± 4.08 µmol/moles of creatinine) and plasma homocysteine (16.55 ± 0.48 µmol/L) levels in the B₁₂ deficient group was observed, while these were equal to control in the Spirulina fed group (8.71 ± 0.48 µmol/mol of creatinine and 6.88 ± 1.18 µmol/L, respectively). The vitamin B₁₂ levels in serum (874.27 ± 89.69), plasma (615.53 ± 26.5 pg/ml), kidney (10.19 ± 1.066 ng/g), and liver tissues (6.37 ± 0.62 ng/g) in the Spirulina fed group were similar to control. Severe atrophic changes in the testes and altered tissue architecture in lung and spleen as seen in the B₁₂ deficient group were normalized in the Spirulina fed group. The study validates that Spirulina can improve the vitamin B₁₂ status. PRACTICAL APPLICATIONS: The present study showed that the supplementation of Spirulina in the diet of vitamin B₁₂ deficient rats leads to the normalization of vitamin B₁₂ deficiency-induced circulatory and functional biomarkers along with biochemical and histological changes. Vegetarian sources for vitamin B₁₂ are limited and the results presented here provide scientific validation for the use of Spirulina as a potential vegetarian source of bioavailable vitamin B₁₂ .

Seminal but not Serum Levels of Holotranscobalamin are Altered in Morbid Obesity and Correlate with Semen Quality: A Pilot Single Centre Study

Vitamin B12 (cobalamin) is an essential cofactor in the one-carbon metabolism. One-carbon metabolism is a set of complex biochemical reactions, through which methyl groups are utilised or generated, and thus plays a vital role to many cellular functions in humans. Low levels of cobalamin have been associated to metabolic/reproductive pathologies. However, cobalamin status has never been investigated in morbid obesity in relation with the reduced semen quality. We analysed the cross-sectional data of 47-morbidly-obese and 21 lean men at Careggi University Hospital and evaluated total cobalamin (CBL) and holotranscobalamin (the active form of B12; holoTC) levels in serum and semen. Both seminal and serum concentrations of holoTC and CBL were lower in morbidly obese compared to lean men, although the difference did not reach any statistical significance for serum holoTC. Seminal CBL and holoTC were significantly higher than serum levels in both groups. Significant positive correlations were observed between seminal holoTC and total sperm motility (r = 0.394, p = 0.012), sperm concentration (r = 0.401, p = 0.009), total sperm number (r = 0.343, p = 0.028), and negative correlation with semen pH (r = -0.535, p = 0.0001). ROC analysis supported seminal holoTC as the best predictor of sperm number (AUC = 0.769 ± 0.08, p = 0.006). Our findings suggest that seminal rather than serum levels of holoTC may represent a good marker of semen quality in morbidly obese subjects.

Mechanisms of honey on testosterone levels

Testosterone is an anabolic steroid and the principal sex hormone in males. Maintaining adequate levels of testosterone throughout the life span of male is very desirable, especially it is now well-known that low levels of testosterone is associated with various aging diseases/disorders. Therefore, still, so many research studies have focused on enhancing serum levels of testosterone in males. Here, we intended to systematically discuss and present the impact of honey on serum levels of testosterone in males. This was conducted by searching PubMed, Scopus, and Embase electronic databases for research articles from May 1993 through April 2019 using the keywords “honey” and “honeybee” versus “testosterone”. Moreover, references from relevant published articles were also reviewed and cited to frame an integral discussion, conclusion, and future research needs. In conclusion, the collective evidence, which is mainly based on in vivo system studies, reveals that oral administration of honey increases serum testosterone level in males. Mechanistically, honey may increase serum level of testosterone by increasing the production of luteinizing hormone, enhancing the viability of Leydig cells, reducing oxidative damage in Leydig cells, enhancing StAR gene expression, and inhibiting aromatase activity in the testes. However, further research studies on humans, mainly clinical trials, in this specific research approach are still needed to confirm the effect of honey on testosterone.

Human Semen Samples with High Antioxidant Reservoir May Exhibit Lower Post-Cryopreservation Recovery of Sperm Motility

Cryopreservation-thawing of human semen was found to reduce the level of antioxidant activity surrounding the sperm, which may negatively affect post-cryopreservation (post-thaw) recovery of sperm motility. Therefore, the current manufactured cryoprotectant media have been supplemented with certain antioxidants to preserve the loss in seminal antioxidant activity. In this study, we aimed to explore the correlation between total antioxidant capacity (TAC) of human semen samples before cryopreservation and the post-thaw recovery of sperm motility. Normal semen specimens (n = 77) were recruited in this study. Sperm motility was measured for each semen sample before and after cryopreservation and the post-thaw recovery of sperm motility was calculated. Seminal TAC was measured spectrophotometrically before cryopreservation for each semen sample using the sensitive cupric ion-reducing antioxidant capacity (CUPRAC) method. The results from this study showed that the post-thaw recovery of sperm motility is negatively correlated (p = 0.0404, p = 0.0402) with the absorbance at 450 nm and the values of seminal TAC in terms of µM Trolox equivalents, as evaluated by CUPRAC, respectively. In conclusion, the total antioxidant reservoir in each ejaculated semen specimen could be a factor in determining the post-thaw recovery of sperm motility toward lower recovery for semen specimens of high antioxidant content.

Vitamin B12 Prevents Cimetidine-Induced Androgenic Failure and Damage to Sperm Quality in Rats

Cimetidine, used as an anti-ulcer and adjuvant treatment in cancer therapy, causes disorders in the male reproductive tract, including steroidogenesis. However, its effect on sperm quality and male fertility has been poorly addressed. Since vitamin B₁₂ has demonstrated to recover spermatogonia number and sperm concentration in cimetidine-treated rats, we evaluated the impact of cimetidine on sperm quality and fertility potential and whether vitamin B₁₂ is able to prevent the harmful effect of this drug on steroidogenesis and sperm parameters. Adult male rats were treated for 52 consecutive days as follows: cimetidine group (100 mg/kg of cimetidine), cimetidine/vitamin B₁₂ group (100 mg/kg of cimetidine + 3 μg vitamin B₁₂), vitamin B₁₂ group (3 μg vitamin B₁₂) and control group (saline). Serum testosterone levels and immunofluorescence associated to western blot for detection of 17β-HSD6 were performed. Sperm morphology and motility, mitochondrial activity, acrosome integrity, DNA integrity by Comet assay, lipid peroxidation as well as fertility potential were analyzed in all groups. Apoptotic spermatids were also evaluated by caspase-3 immunohistochemistry. In the cimetidine-treated animals, reduced serum testosterone levels, weak 17β-HSD6 levels and impaired spermiogenesis were observed. Low sperm motility and mitochondrial activity were associated with high percentage of sperm tail abnormalities, and the percentage of spermatozoa with damaged acrosome and DNA fragmentation increased. MDA levels were normal in all groups, indicating that the cimetidine-induced changes are associated to androgenic failure. In conclusion, despite the fertility potential of rats was unaffected by the treatment, the sperm quality was significantly impaired. Therefore, considering a possible sperm-mediated transgenerational inheritance, the long term offspring health needs to be investigated. The administration of vitamin B₁₂ to male rats prevents the androgenic failure and counteracts the damage inflicted by cimetidine upon sperm quality, indicating that this vitamin may be used as a therapeutic agent to maintain the androgenic status and the sperm quality in patients exposed to androgen disrupters.

Effect of Coenzyme Q10 Supplementation on Testosterone

Enhancing testosterone production in males is a continuous research direction for many scientists in the field, due to its role as a principal sex hormone and as a crucial modulator of well-being and general health in humans. Since 1978, there have been more than 30 studies that have connected coenzyme Q₁₀ and testosterone. Such a link is attributable to the vigorous biological role of coenzyme Q₁₀ as a crucial member in the energy production route in humans and animals, which is thought to have a positive influence on testosterone production, and hence on infertility, particularly male infertility. However, this connection has not yet been deliberated. The present work systematically reviews and summarizes the influence of coenzyme Q₁₀ supplementation on testosterone. To accomplish this purpose, the Scopus, PubMed, and Web of Science databases were searched using the keywords “coenzyme Q₁₀” versus “testosterone” for English language papers from November 1978 through October 2018. Relevant articles were also discussed and included to address an integral discussion. In summary, to date the studies conducted on human males reveal insignificant effects of coenzyme Q₁₀ supplementation on testosterone. Similarly, rather than the reproductive toxicity studies, the studies conducted on animals did not show any positive influence of coenzyme Q₁₀ on testosterone. However, coenzyme Q₁₀ supplementation was found to ameliorate the reduction in testosterone induced by chemical reproductive toxicants, mainly by neutralizing the damaging effect of the generated free radicals. However, collectively these findings require further confirmation by additional research studies.

Ginger and Testosterone

Enhancing and protecting testosterone production is one target for many scientists because of its crucial role as a primary sex hormone in males. Several in vivo trials have utilized different dietary supplements and medicinal plants to enhance testosterone production in males. Since 1991, various in-vivo, as well as basic research studies, have discovered a link between ginger (Zingiber officinale) and testosterone. However, such a link has not yet been collectively reviewed. This review systematically discusses and summarizes the effect of ginger and ginger extracts on testosterone. To achieve this contribution, we searched the PubMed, Scopus, and Web of Science databases for English language articles (full texts or abstracts) from November 1991 through August 2018 using the keywords "ginger" and "Zingiber officinale" versus "testosterone". Additionally, the references from related published articles were also reviewed, only if relevant. In conclusion, the mainstream of research that links ginger to testosterone demonstrated that ginger supplementation, particularly in oxidative stress conditions, enhances testosterone production in males. The mechanisms by which this occurs mainly by enhancing luteinizing hormone (LH) production, increasing the level of cholesterol in the testes, reducing oxidative stress and lipid peroxidation in the testes, enhancing the activity of the antioxidant enzymes, normalizing blood glucose, increasing blood flow in the testes, increasing testicular weight, and recycling testosterone receptors. However, the effect of ginger on testosterone is not yet confirmed in humans. Therefore, clinical studies in this context of research are imperative.

Role of Uric Acid in Semen

Since 1963, various research studies and reports have demonstrated the role of uric acid (2,6,8-trihydroxypurine), an end product of adenosine and guanosine catabolism, on semen quality and sperm function. However, this effect has not yet been collectively discussed, even though uric acid has been a well-recognized constituent in semen. Here, we systematically and comprehensively discuss and summarize the role/effect of uric acid in semen quality by searching the main databases for English language articles considering this topic. Additionally, certain significant and relevant papers were considered to support discussions and perceptions. In conclusion, uric acid contributes to maintaining and enhancing sperm motility, viability, and morphology; therefore, protecting sperm function and fertilizing ability. This contribution is performed mainly by neutralizing the damaging effect of oxidizing (e.g., endogenous free radicals and exogenous toxins) and nitrating agents and enhancing certain bioactive enzymes in spermatozoa. In contrast, high levels of uric acid may induce adverse effects to sperm function, at least in part, by reducing the activity of vital enzymes in spermatozoa. However, further research, mainly clinical, is still required to fully explore the role/effect of uric acid in semen.

Colorectal polyp risk is linked to an elevated level of homocysteine

Several studies have reported an association between levels of folate, homocysteine, and vitamin B₁₂ and the risk of colorectal polyps. Here, our aim is to examine the possible effect of folate, homocysteine, and vitamin B₁₂ levels on the risk of colorectal polyps by means of meta-analysis based quantitative synthesis. According to our inclusion/exclusion criteria, a total of 13 case–control studies were enrolled. The P-value of the association test, standard mean difference (SMD), and 95% confidence interval (CI) were calculated. Pooled analysis data showed a negative correlation between the risk of colorectal polyps and the levels of serum folate, red blood cell (RBC) folate, or vitamin B₁₂ (all P>0.05). Nevertheless, for homocysteine level, we also observed a statistically significant difference between cases and controls in the overall and subgroup analysis of hospital-based control (HB), population-based control (PB), Chinese, Caucasian, or Asian (all P<0.05, SMD > 0). We found that increased levels of homocysteine may be statistically and significantly related to the risk of colorectal polyps.