Effect of ascorbic acid on male fertility

Antioxidant Supplementation on Male Fertility-A Systematic Review

Our aim was to review the current literature regarding the effect of antioxidant supplementation (AS) on male fertility parameters, as AS is commonly used to treat male infertility due to the availability and affordability of antioxidants in many parts of the world.

MATERIALS AND METHODS

PubMed, Medline, and Cochrane electronic bibliographies were searched using the modified Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guidelines to evaluate studies on the benefit of antioxidant therapy on infertile men. Results were analyzed regarding the following aspects: (a) ingredient and dose; (b) potential mechanism of action and rationale for use; and (c) effect on various reported outcomes.

RESULTS

Thus, 29 studies found a substantial positive effect of AS on outcomes of assisted reproductive therapy (ART), WHO semen parameters, and live-birth rate. Carnitines, Vitamin E and C, N-acetyl cysteine, coenzyme Q10, selenium, zinc, folic acid, and lycopene were beneficial ingredients. Nevertheless, some studies did not show a substantial change in one or more factors.

CONCLUSION

AS seems to have a positive effect on male fertility. Environmental factors may play an increasing role in fertility. Further studies are needed to determine the optimal AS combination and the influence of environmental factors.

Are antioxidants a viable treatment option for male infertility?

Oxidative stress is caused by an imbalance between ROS and antioxidants, which plays a significant role in the pathophysiology of many human diseases. There is extensive evidence highlighting the role of oxidative stress in male infertility due to elevated levels of sperm DNA fragmentation and abnormal semen parameters. The use of antioxidants is a potential therapeutic option to reduce ROS and improve semen quality. The appeal is that antioxidants can be easily obtained over the counter and are considered all-natural and therefore healthy. The hypothesis has been that by decreasing oxidative stress, antioxidants may be used for the treatment of male infertility. While initial studies of antioxidant supplementation suggested a beneficial role in the management of male subfertility, additional research has questioned the benefit of these therapies. The focus of this article is to present recent evidence assessing the viability of antioxidant therapy in the treatment of male infertility.

GSTO2 Isoforms Participate in the Oxidative Regulation of the Plasmalemma in Eutherian Spermatozoa during Capacitation

In addition to perinuclear theca anchored glutathione-s-transferase omega 2 (GSTO2), whose function is to participate in sperm nuclear decondensation during fertilization (Biol Reprod. 2019, 101:368–376), we herein provide evidence that GSTO2 is acquired on the sperm plasmalemma during epididymal maturation. This novel membrane localization was reinforced by the isolation and identification of biotin-conjugated surface proteins from ejaculated and capacitated boar and mouse spermatozoa, prompting us to hypothesize that GSTO2 has an oxidative/reductive role in regulating sperm function during capacitation. Utilizing an inhibitor specific to the active site of GSTO2 in spermatozoa, inhibition of this enzyme led to a decrease in tyrosine phosphorylation late in the capacitation process, followed by an expected decrease in acrosome exocytosis and motility. These changes were accompanied by an increase in reactive oxygen species (ROS) levels and membrane lipid peroxidation and culminated in a significant decrease in the percentage of oocytes successfully penetrated by sperm during in vitro fertilization. We conclude that GSTO2 participates in the regulation of sperm function during capacitation, most likely through protection against oxidative stress on the sperm surface.

Male Oxidative Stress Infertility (MOSI): Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility

Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause.

What are the effects of vitamin C on sperm functional properties during direct swim-up procedure?

Direct swim-up procedure is widely used to separate the motile competent spermatozoa from the antioxidant-rich semen. Subsequently, spermatozoa become more vulnerable to reactive oxygen species (ROS) due to their cytological characteristics. The effect of vitamin C, a highly concentrated antioxidant in the semen, on direct swim-up-enriched sperm population is not fully investigated. Therefore, the aim of the present study was to assess the effect of vitamin C on sperm functional properties during direct swim-up procedure. Semen samples were collected from 22 participants. Each semen sample was divided into several aliquots. The first portion was overlaid with sperm medium without ascorbic acid (0 µM AA). The second and third fractions were overlaid with sperm medium supplemented with 300 µM and 600 µM AA; respectively. After 1 h of incubation, basic sperm parameters, intracellular ROS levels, acrosome reaction, chromatin integrity, and glucose uptake were assessed. Swim-up without AA significantly increased the percentage of ROS(+) spermatozoa compared with the raw semen (P<0.01). Interestingly, swim-up with 300 µM AA did not increase the percentage of ROS(+) sperm compared with the raw semen. In parallel, the percentage of sperm with altered chromatin integrity was significantly lower in the 300 µM AA group compared with that in the raw semen (P<0.05). These findings suggest that supplementation of vitamin C to sperm medium could be beneficial for direct swim-up-derived spermatozoa.

Myrciaria dubia "camu camu" flour as a magnetoprotector in male mouse infertility

Possible adverse effects of extremely low frequency magnetic fields (ELF-MF) are linked to a decrease of antioxidant defenses and the production of free radicals. The increase of free radicals affects the mitochondrial functionality inducing apoptosis, which affects the phosphorylation and generation of key ATP in fertilization. Myrciaria dubia, known as "camu camu," is a fruit with high levels of ascorbic acid, which exerts an important antioxidant function in the prevention of premature cell damage. In this study, the effect of Myrciaria dubia flour on oxidative damage produced by ELF-MF (610 μT) was evaluated by detecting the activity of endogenous mitochondrial oxidoreductase enzymes in a complete sperm cycle of mice. We found that the MF caused a significant (P < 0.05) decrease in sperm quality, whereas the groups supplied with Myrciaria dubia flour (50 and 75 mg/kg of body mass) in ELF-MF exposure showed a significant recovery (P < 0.05) in parameters of viability, percentage of plasma membrane integrity and mitochondrial activity, and index of epidymal sperm. This suggests that Myrciaria dubia flour would have an antioxidant activity that counteracts the damaging effects of ELF-MF in spermatogenesis and could be used as a natural ELF-MF protector. Bioelectromagnetics. 40:91-103, 2019. © 2019 Bioelectromagnetics Society.

Seminal reactive oxygen species and total antioxidant capacity: Correlations with sperm parameters and impact on male infertility

Objective

The aim of this study was to measure reactive oxygen species (ROS) production and total antioxidant capacity (TAC) in the seminal fluid of the male partners in couples undergoing intrauterine insemination and to evaluate correlations between these values and their semen parameters.

Methods

The study was conducted at Vamsam Fertility Center, Coimbatore, India and enrolled 110 male patients from whom semen samples were collected. ROS production was measured by a thiobarbituric acid reactive species assay, and TAC was measured by a 2,2-diphenyl-2-picrylhydrazyl free radical assay. The differences in the TAC and malondialdehyde (MDA) levels between the subfertile and fertile groups were analysed. Correlations between sperm parameters and TAC and MDA levels were statistically analysed, and cutoff values with respect to the controls were determined. All hypothesis tests used were two-tailed, with statistical significance assessed at the level of p<0.05.

Results

A total of 87 subfertile and 23 fertile men were included in the study. The mean MDA level was significantly higher in the subfertile subjects than in the fertile subjects, and the mean antioxidant level was significantly lower in the subfertile subjects than in the fertile subjects. Seminal MDA levels were negatively associated with sperm concentration, motility, and morphology, whereas the opposite was seen with TAC levels.

Conclusion

Measurements of seminal TAC and ROS are valuable for predicting semen quality, and hence predicting the outcomes of fertility treatment.

Male Infertility: The Effect of Natural Antioxidants and Phytocompounds on Seminal Oxidative Stress

Defective sperm function has been identified as the most common cause of infertility. The objective of this study was to review recent findings on the effects of various antioxidants on male fertility. High amounts of poly unsaturated fatty acid are found in the mammalian spermatozoa membranes, thereby making them susceptible to lipid peroxidation. Although, free radicals and reactive oxygen species (ROS) play major roles in reproduction, they are strongly associated with oxidative stress. Furthermore, factors such as obesity, inflammation, pollutants and cigarette smoking are negatively correlated with spermatogenesis. Endogenous antioxidants system exists to mediate these damages. In a normal physiological state, the seminal plasma contains antioxidant enzyme mechanism that is capable of quenching these ROS as well as protecting the spermatozoa against any likely damage. However, high level of ROS triggered by inflammatory cells and oxidation of fatty acid in obese subjects may down play antioxidant mechanism resulting in oxidative stress. Evaluation of such oxidative stress is the first step in the treatment of male infertility through administration of suitable antioxidant. Notably, antioxidant such as vitamin E and C, carotenoids and carnitine have been found beneficial in restoring a balance between ROS generation and scavenging activities. There are emerging evidences that herbal products can also boost male reproductive functions. Nonetheless, a good lifestyle, regular exercise, avoidance of stress and observing safety rules at work are habits that can reverse male infertility.

Effects of supplemental dietary vitamin C on quality of semen from Nile tilapia (Oreochromis niloticus) breeders

The objective of this study was to evaluate the effects of vitamin C on growth and quality of semen from Oreochromis niloticus breeders. One hundred and sixty males were fed with different levels of vitamin C (0, 261, 599 and 942 mg/kg diet). The higher weight values were recorded for 599 (166 g) and 942 (175 g) mg of vitamin C/kg diet. Sperm motility, vigour and concentration were higher with 599 and 942 mg of vitamin C/kg diet. The semen volume, gonadosomatic index and plasma protein data from the last week showed a direct relationship with increasing levels of vitamin C. No changes were observed in the hepatosomatic index and blood glucose. The haematocrit and erythrocyte showed higher values estimated by equations derived at 850 and 638 mg vitamin C/kg diet, respectively. The leucocytes were inversely proportional to the increasing levels of vitamin C. After 100 days of feeding, animals fed the diet containing 942 mg vitamin C/kg diet had higher sperm motility, linearity, curvilinear velocity, straight line velocity and average path velocity (p < .05). Higher values of beat cross-frequency were observed in broodfish fed diets containing 942 and 599 mg vitamin C/kg. The different vitamin C levels did not cause differences in straightness, lateral head displacement and sperm morphology. For Nile tilapia males on intensive rearing and handling conditions, vitamin C levels between 599 and 942 mg/kg may be used for a better performance and quality of semen.

Ameliorative potential of α-tocopherol against flubendiamide and copper-induced testicular-insult in Wistar rats

Study was undertaken to evaluate ameliorative potential of α-tocopherol against copper sulphate and flubendiamide alone and in combination-induced toxicity in rats following 90 days exposure. Absolute and relative organ weights did not differ between treatments groups. Increase of LPO in copper and flubendiamide intoxicated rats but modest increase in copper + flubendiamide group. GSH and activities of SOD, GPx and GST showed moderate decrease in intoxicated groups. Reduced CAT activity in alone exposed groups was observed. ACP, ALP and SDH remain unaltered. Increase in LDH, γ-GT, abnormal sperm and reduced 17β-HSD, percent live and HOST +ve sperms and testosterone level was observed in all three exposed groups. Xenobiotics alone and in combination exhibited degenerative germinal epithelium, necrotic germ cells, loss of spermatozoa and spermatids. Treatment with α-tocopherol, reparative potential was observed as values of most of the parameters including testicular histoarchitecture were restored.

The impact of lifestyle modifications, diet, and vitamin supplementation on natural fertility

BACKGROUND

Infertility is a relatively common condition. When patients are confronted with this diagnosis, there are medical, psychological, and financial sequelae. Patients often wonder if there is anything they can do to optimize their natural fertility or increase the effectiveness of infertility treatments.

FINDINGS

If there is a clear impact on fertility, such as with smoking and alcohol, cessation should be advised. Similarly, weight loss should be recommended if the BMI is in the overweight and obese category, and weight gain should be recommended for an underweight BMI. The evidence surrounding other lifestyle modifications is less clear. There are conflicting data regarding an optimal fertility diet and consumption of vitamins and supplements. Antioxidants seem to improve semen parameters in men, but the effect on female fertility is less clear. If conflicting evidence exists, such as with caffeine consumption or exercise, moderation should be emphasized. Finally, the diagnosis of infertility and subsequent fertility treatments are stressful for both partners. The psychological aspects should not be ignored and methods such as yoga and cognitive behavioral therapy may be beneficial.

CONCLUSION

Continued research will determine the optimal lifestyle modifications to achieve pregnancy.

Utility of antioxidants during assisted reproductive techniques: an evidence based review

Assisted reproductive technology (ART) is a common treatment of choice for many couples facing infertility issues, be it due to male or female factor, or idiopathic. Employment of ART techniques, however, come with its own challenges as the in vitro environment is not nearly as ideal as the in vivo environment, where reactive oxygen species (ROS) build-up leading to oxidative stress is kept in check by the endogenous antioxidants system. While physiological amounts of ROS are necessary for normal reproductive function in vivo, in vitro manipulation of gametes and embryos exposes these cells to excessive ROS production either by endogenous or exogenous environmental factors. In this review, we discuss the sources of ROS in an in vitro clinical setting and the influence of oxidative stress on gamete/embryo quality and the outcome of IVF/ICSI. Sources of ROS and different strategies of overcoming the excessive generation of ROS in vitro are also highlighted. Endogenously, the gametes and the developing embryo become sources of ROS. Multiple exogenous factors act as potential sources of ROS, including exposure to visible light, composition of culture media, pH and temperature, oxygen concentration, centrifugation during spermatozoa preparation, ART technique involving handling of gamete/embryo and cryopreservation technique (freeze/thawing process). Finally, the use of antioxidants as agents to minimize ROS generation in the in vitro environment and as oral therapy is highlighted. Both enzymatic and non-enzymatic antioxidants are discussed and the outcome of studies using these antioxidants as oral therapy in the male or female or its use in vitro in media is presented. While results of studies using certain antioxidant agents are promising, the current body of evidence as a whole suggests the need for further well-designed and larger scale randomized controlled studies, as well as research to minimize oxidative stress conditions in the clinical ART setting.

Empirical medical therapy in idiopathic male infertility: Promise or panacea?

Male factors account for 20%-50% of cases of infertility and in 25% of cases, the etiology of male infertility is unknown. Effective treatments are well-established for hypogonadotropic hypogonadism, male accessory gland infection, retrograde ejaculation, and positive antisperm antibody. However, the appropriate treatment for idiopathic male infertility is unclear. Empirical medical treatment (EMT) has been used in men with idiopathic infertility and can be divided into two categories based on the mode of action: hormonal treatment and antioxidant supplementation. Hormonal medications consist of gonadotropins, androgens, estrogen receptor blockers, and aromatase inhibitors. Antioxidants such as vitamins, zinc, and carnitines have also been widely used to reduce oxidative stress-induced spermatozoa damage. Although scientifically acceptable evidence of EMT is limited because of the lack of large, randomized, controlled studies, recent systematic reviews with meta-analyses have shown that the administration of gonadotropins, anti-estrogens, and oral antioxidants results in a significant increase in the live birth rate compared with control treatments. Therefore, all physicians who treat infertility should bear in mind that EMT can improve semen parameters and subsequent fertility potential through natural intercourse.

Semen quality in relation to antioxidant intake in a healthy male population

OBJECTIVE

To assess the relationship between dietary antioxidant intake and semen quality in young healthy males.

DESIGN

Cross-sectional study.

SETTING

University and college campuses in the Rochester, New York, area.

PATIENT(S)

One hundred eighty-nine university-aged men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen volume, total sperm count, concentration, motility, total motile count, and morphology.

RESULT(S)

Progressive motility was 6.5 (95% confidence interval [CI], 0.6, 12.3) percentage units higher among men in the highest quartile of β-carotene intake compared with men in the lowest quartile. Similar results were observed for lutein intake. Lycopene intake was positively related to sperm morphology. The adjusted percentages (95% CI) of morphologically normal sperm in increasing quartiles of lycopene intake were 8.0 (6.7, 9.3), 7.7 (6.4, 9.0), 9.2 (7.9, 10.5), and 9.7 (8.4, 11.0). There was a nonlinear relationship between vitamin C intake and sperm concentration, with men in the second quartile of intake having, on average, the highest sperm concentrations and men in the top quartile of intake having the lowest concentrations.

CONCLUSION(S)

In a population of healthy young men, carotenoid intake was associated with higher sperm motility and, in the case of lycopene, better sperm morphology. Our data suggest that dietary carotenoids may have a positive impact on semen quality.

Semen quality in relation to antioxidant intake in a healthy male population

OBJECTIVE

To assess the relationship between dietary antioxidant intake and semen quality in young healthy males.

DESIGN

Cross-sectional study.

SETTING

University and college campuses in the Rochester, New York, area.

PATIENT(S)

One hundred eighty-nine university-aged men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen volume, total sperm count, concentration, motility, total motile count, and morphology.

RESULT(S)

Progressive motility was 6.5 (95% confidence interval [CI], 0.6, 12.3) percentage units higher among men in the highest quartile of β-carotene intake compared with men in the lowest quartile. Similar results were observed for lutein intake. Lycopene intake was positively related to sperm morphology. The adjusted percentages (95% CI) of morphologically normal sperm in increasing quartiles of lycopene intake were 8.0 (6.7, 9.3), 7.7 (6.4, 9.0), 9.2 (7.9, 10.5), and 9.7 (8.4, 11.0). There was a nonlinear relationship between vitamin C intake and sperm concentration, with men in the second quartile of intake having, on average, the highest sperm concentrations and men in the top quartile of intake having the lowest concentrations.

CONCLUSION(S)

In a population of healthy young men, carotenoid intake was associated with higher sperm motility and, in the case of lycopene, better sperm morphology. Our data suggest that dietary carotenoids may have a positive impact on semen quality.

A randomized steady-state bioavailability study of synthetic versus natural (kiwifruit-derived) vitamin C

Whether vitamin C from wholefoods has equivalent bioavailability to a purified supplement remains unclear. We have previously showed that kiwifruit provided significantly higher serum and tissue ascorbate levels than synthetic vitamin C in a genetically vitamin C-deficient mouse model, suggesting a synergistic activity of the whole fruit. To determine if these results are translatable to humans, we carried out a randomized human study comparing the bioavailability of vitamin C from kiwifruit with that of a vitamin C tablet of equivalent dosage. Thirty-six young non-smoking adult males were randomized to receive either half a gold kiwifruit (Actinidia Chinensis var. Hort 16A) per day or a comparable vitamin C dose (50 mg) in a chewable tablet for six weeks. Ascorbate was monitored weekly in fasting venous blood and in urine, semen, leukocytes, and skeletal muscle (vastus lateralis) pre- and post-intervention. Dietary intake of vitamin C was monitored using seven day food and beverage records. Participant ascorbate levels increased in plasma (P < 0.001), urine (P < 0.05), mononuclear cells (P < 0.01), neutrophils (P < 0.01) and muscle tissue (P < 0.001) post intervention. There were no significant differences in vitamin C bioavailability between the two intervention groups in any of the fluid, cell or tissue samples tested. Overall, our study showed comparable bioavailability of synthetic and kiwifruit-derived vitamin C.

The role of nutraceuticals in male fertility

Nutraceuticals are food products that that can provide medical or health benefits by preventing or treating disease processes. The high costs associated with assisted reproductive techniques for male infertility have led consumers to find less expensive alternatives for potential treatment. Nutraceuticals are widely available and have many antioxidant properties. This articles reviews the current English literature regarding readily available nutraceuticals and their potential effects on male infertility and potential side effects with excess intake.

Clinical relevance of vitamin C among lead-exposed infertile men

AIMS AND OBJECTIVES

A cross-sectional study was designed by targeting 120 male workers occupationally exposed to lead from a battery-manufacturing industry situated at the Patancheru industrial area, Hyderabad, Andhra Pradesh, India, to see the impact of lead on testicular dysfunction with reference to infertility. Further, the study was designed to see the in vivo effect of an antioxidant in the form of vitamin C, prophylactically administered at the dose of 1000 mg/day for five consecutive days in a week for 3 months.

METHODOLOGY

Blood samples and semen samples were collected from 120 men in the study group exposed to lead, and 120 healthy human subjects, who have no history of exposures to chemicals, were selected as controls for comparison. The mean age of the workers who participated in this study falls in the range of 25-55 years. The semen samples were collected with due consent of the industrial workers to perform the conventional semen analysis and the measure of sperm DNA fragmentation by the comet assay.

RESULTS

Industrial workers showed a statistically significant increase in sperm motility (p<0.001), sperm total count (p<0.001), and a statistically significant decrease in abnormal sperm morphology (p<0.001) after vitamin C prophylaxis. The comet assay also showed similar results, where there is a statistically significant decrease in alkaline-labile sites and a statistically significant decrease in the mean tail length of the comet when compared to the control group (p<0.001) after vitamin C prophylaxis.

CONCLUSION

This study leads us to conclude that the lead compound interferes with the testicular function, inducing its activity and also by exerting its effect on sperm DNA, leading to fragmentation. Further, the prophylaxis with antioxidant treatment may offer protection against the reactive oxygen species (ROS)-induced DNA damage, which is a major cause in the etiology of male infertility.

The protective role of ascorbic acid in burn-induced testicular damage in rats

OBJECTIVE

To investigate the ability of ascorbic acid to protect the testes from damage in severe burns.

DESIGN

Experimental study.

SETTING

University of Lagos Medical School, Department of Anatomy.

ANIMALS

28 adult male Wistar rats (250-300 g).

INTERVENTION

Third degree burn was induced on 40% body surface area of rats and they were given ascorbic acid at 4 mg/kg over 8 weeks.

MAIN OUTCOME MEASURED

Weight of reproductive organs and epididymal sperm parameters were measured. Oxidative status was assayed and a semi-quantitative assessment of histologic changes was also carried out.

RESULTS

Burn caused severe seminiferous tubular damage, especially germ cell loss (p<0.05). This was matched by significant reduction in sperm density and morphology (p<0.05). Burn also increased oxidative stress, with elevated malondialdehyde (MDA) levels (p<0.01) and changes in catalase and superoxide dismutase enzyme levels. Ascorbic acid prevented the changes in all sperm parameters. It normalized MDA levels (p<0.01) and attenuated changes in the levels of catalase and superoxide dismutase. Ascorbic acid treatment also significantly reduced histologic damage to seminiferous tubules.

CONCLUSION

This study shows that severe thermal injury causes significant testicular damage and impairs spermatogenesis. It also shows that ascorbic acid protects the testis from such damage and therefore has the potential to be a useful adjunct therapy during treatment of young males with severe burns.

Antioxidants to enhance fertility: role of eNOS and potential benefits

The use of antioxidants is now often used as a pharmacological adjunct to limit infertility. Indeed, the lay public rightly perceives oxidative stress and, thus, antioxidant treatment as important modulators of infertility. While the direct effects of antioxidant treatment on the quality of semen and oocytes are still under investigation, a significant body of evidence points to loss of vascular tone as a root-cause of erectile dysfunction and, possibly, alterations to female reproduction. In this article, we will critically review the often neglected link between vascular dysfunction and infertility. A particular emphasis will be on the potential use of antioxidants to increase fertility and promote conception.

The role of antioxidant therapy in the treatment of male infertility

Oxidative stress contributes to defective spermatogenesis leading to male factor infertility. The aim of this study was to review the current literature on the effects of various antioxidants to improve fertilisation and pregnancy rates. The sources of literature were Pubmed and the Cochrane data base. Reviewing the current literature revealed that Carnitines and vitamin C and E have been clearly shown to be effective by many well-conducted studies and may be considered as a first line treatment. The efficacy of antioxidants, such as glutathione, selenium and coenzyme Q10 has been demonstrated by few, but well-performed studies, and may be considered second line treatment. There is, however, a need for further investigation with randomised controlled studies to confirm the efficacy and safety of antioxidant supplementation in the medical treatment of idiopathic male infertility as well as the need to determine the ideal dose of each compound to improve semen parameters, fertilisation rates and pregnancy outcomes.

Oxidative stress and antioxidants for idiopathic oligoasthenoteratospermia: Is it justified?

Oxidative stress contributes to defective spermatogenesis and the poor quality of sperm associated with idiopathic male factor infertility. The aim of this study was to review the current literature on the effects of various types of antioxidant supplements in patients to improve fertilization and pregnancy rates in subfertile males with idiopathic oligoasthenoteratozoospermia (iOAT). Review of recent publications through PubMed and the Cochrane database. Oxidative stress is implicated in impaired spermatogenesis leading to the poor semen parameters and increased DNA damage and apoptosis in iOAT. Strategies to modulate the level of oxidative stress within the male reproductive tract include the use of oral antioxidant compounds to reinforce the body's defence against oxidative damage. In our evaluation, carnitines were considered the most established pharmacotherapeutic agent to treat iOAT, as evidence and data concerning carnitine supplementation have been shown to be most consistent and relevant to the population of interest. Other therapies, such as combined vitamin E and C therapy, are still considered controversial as vitamin C can act as a pro-oxidant in certain instances and the results of randomized controlled trials have failed to show significant benefit to sperm parameters and pregnancy rates. There is a need for further investigation with randomized controlled studies to confirm the efficacy and safety of antioxidant supplementation in the medical treatment of idiopathic male infertility as well as the need to determine the dosage required to improve semen parameters, fertilization rates and pregnancy outcomes in iOAT.

Ascorbic Acid in human seminal plasma: determination and its relationship to sperm quality

The objective of the present study was to assess the ascorbic acid (AA) levels in seminal plasma of the fertile and infertile men and to investigate its relationship with sperm count, motility and normal morphology. Semen samples were provided by fertile [smoker (n = 25), nonsmoker (n = 21)] and infertile men [smoker (n = 23), nonsmoker (n = 32)]. A simplified method of reverse phase high performance liquid chromatography (RP-HPLC) procedure using UV detection was applied for the determination of seminal AA. Fertile subjects, smoker or not, demonstrated significantly higher seminal AA levels than any infertile group (p<0.01). Nonsmokers had high, but no significant, mean AA levels in their seminal plasma compared with smokers. Seminal AA in fertile and infertile (smokers or nonsmokers) males correlated significantly with the percentage of spermatozoa with normal morphology (p<0.01). Seminal AA decreased significantly in infertile men. Decrease of seminal plasma AA is a risk factor for low normal morphology of spermatozoa and idiopathic male infertility. Measurement of seminal AA in the seminal plasma of males with a history of subfertility or idiopathic infertility is necessary and can be helpful in fertility assessment.

Withania somnifera improves semen quality by regulating reproductive hormone levels and oxidative stress in seminal plasma of infertile males

OBJECTIVE

To investigate the impact of Withania somnifera roots on semen profile, oxidative biomarkers, and reproductive hormone levels of infertile men.

DESIGN

Prospective study.

SETTING

Departments of Biochemistry and Urology, Chhatrapati Shahuji Maharaj Medical University, Lucknow, India.

PATIENT(S)

Seventy-five normal healthy fertile men (control subjects) and 75 men undergoing infertility screening.

INTERVENTION(S)

High-performance liquid chromatography assay procedure for quantization of vitamin A and E in seminal plasma. Biochemical parameters in seminal plasma were estimated by standard spectrophotometric procedures. Estimation of T, LH, FSH, and PRL in blood serum by RIA methods.

MAIN OUTCOME MEASURES(S)

Before and after the treatment, seminal plasma biochemical parameters, antioxidant vitamins, and serum T, LH, FSH, and PRL levels were measured.

RESULT(S)

Withania somnifera inhibited lipid peroxidation and protein carbonyl content and improved sperm count and motility. Treatment of infertile men recovered the seminal plasma levels of antioxidant enzymes and vitamins A, C, and E and corrected fructose. Moreover, treatment also significantly increased serum T and LH and reduced the levels of FSH and PRL.

CONCLUSION(S)

The treatment with W. somnifera effectively reduced oxidative stress, as assessed by decreased levels of various oxidants and improved level of diverse antioxidants. Moreover, the levels of T, LH, FSH and PRL, good indicators of semen quality, were also reversed in infertile subjects after treatment with the herbal preparation.

Protective role of ascorbic acid on subacute sperm toxicity in male New Zealand white rabbits treated with endosulfan

The ameliorating effect of oral ascorbic acid (AA) was evaluated against changes in sperm parameters in New Zealand White (NZW) rabbits treated with endosulfan. Rabbits (6 to 8 months old) were divided into four groups of six animals each. Rabbits in TRT-I served as control and received corn oil by oral gavage for 6 weeks. Rabbits in TRT-II received endosulfan (1 mg/kg bw per day) in corn oil. TRT-III group received oral corn oil daily and ascorbic acid (AA; 20 mg/kg bw) every other day for 6 weeks. TRT-IV group received the same amounts of endosulfan and AA. Endosulfan alone significantly reduced the sperm count and motility and increased the presence of sperm with morphologic problems. AA treatment showed significant amelioration when coupled with endosulfan. Ameliorations were up to control levels in all cases except for sperm motility. The data suggested that AA has beneficial influences in neutralizing the toxic effects of endosulfan in the spermatologic parameters of NZW males.

The effect of ascorbic acid supplementation on sperm quality, lipid peroxidation and testosterone levels of male Wistar rats

This study was conducted to investigate the effects of ascorbic acid supplementation in drinking water on semen quality, lipid peroxidation and plasma testosterone level of male rats. In this investigation, 24 male Wistar rats were used. The animals were divided into three group, and 500, 250 and 0 (control) mg/kg/day ascorbic acid were supplemented with drinking water of rats in Groups A, B and C during 8 weeks, respectively. Ascorbic acid supplementation did not increase in the body weight and weights of the testis, epididymis, seminal vesicles and ventral prostate. Exogenous supplementation with ascorbic acid significantly increased (P<0.05) the concentration of ascorbic acid in the testes and blood plasma, and the level of lipid peroxidation significantly decreased (P<0.05) in these locations. There was no significant difference in spermatozoon motility among the three groups. However, epididymal sperm concentration and plasma testosterone level significantly increased (P<0.05) in the ascorbic acid treated animals when compared to the control animals. The results suggest that ascorbic acid supplementation improves reproductive traits of male rats that are associated with high fertility.

Protective role of ascorbic acid to enhance reproductive performance of male rabbits treated with stannous chloride

The objective of this study was to determine the protective role of ascorbic acid (AA, 40 mg/kg BW) on reproductive performance of male New Zealand White rabbits given sublethal dose (20 mg/kg BW every other day for 12 weeks) of stannous chloride (SnCl2). Results showed that treatment with SnCl2 caused a decrease (P<0.05) in libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. Dead sperm and initial hydrogen ion concentration (pH) were increased. While, relative weights of testes (RTW) and epididymis (REW) were decreased. On the other hand, live body weight (LBW) and dry matter intake (DMI) did not change. Treatment with AA alone caused significant increase in LBW, DMI, RTW, REW and semen characteristics compared to control group. Also, the presence of AA with SnCl2 minimized its harmful effects. Results obtained revealed suggest that assessment of reproductive toxicity of stannous chloride needs to be addressed, and may presently be underestimated. Also, the beneficial influences of AA in counteracting the toxic effects of SnCl2 and improved the reproductive performance of male rabbit was demonstrated.

Vitamin C function and status in chronic disease

Vitamin C is an essential dietary nutrient required as a co-factor for many enzymes, and humans are among the few animals that lack the ability to synthesize the compound from glucose. The reduced form of the vitamin, ascorbic acid, is an especially effective antioxidant owing to its high electron-donating power and ready conversion back to the active reduced form. Concentrations of the vitamin in body tissues and fluids are regulated through interactions of intestinal absorption, cellular transport, and excretion. The amount of vitamin C needed to prevent scurvy is very small and easily obtained in nearly all Western diets. There is great interest in the clinical roles of vitamin C because of evidence that oxidative damage is a root cause of, or at least associated with, many diseases. Population studies show that individuals with high intakes of vitamin C have lower risk of a number of chronic diseases, including heart disease, cancer, eye diseases, and neurodegenerative conditions. However, these results may simply reflect a more healthful diet or lifestyle for individuals with a high vitamin C intake. At present, data from controlled clinical trials have not established that higher intakes of vitamin C alone will help prevent chronic degenerative diseases. However, the evidence that ascorbic acid acts as an important antioxidant in many body tissues is convincing. The new higher Recommended Dietary Allowance (RDA) for vitamin C of 75 mg for women and 90 mg for men is, for the first time, based on the vitamin's role as an antioxidant as well as protection from deficiency. In healthy people, amounts greater than the RDA do not appear to be helpful. Vitamin C nutriture may be more important for people with certain diseases or conditions. High intakes of the vitamin are generally well tolerated; a Tolerable Upper Level was recently set at 2 g based on gastrointestinal upset that sometimes accompanies excessive intakes.

Expression of GM-CSF receptors in male germ cells and their role in signaling for increased glucose and vitamin C transport

We studied the expression and function of the granulocyte-macrophage colony stimulating factor (GM-CSF) receptor in male germ cells. RT-PCR showed expression of mRNAs encoding the alpha- and beta-subunits of the GM-CSF receptor in human testis, and the presence of the alpha- and beta-proteins was confirmed by immunoblotting with anti-alpha and anti-beta-antibodies. Immunolocalization studies showed the level of expression of GM-CSF alpha- and beta-subunits in the germ line in the testis and in ejaculated spermatozoa. Receptor binding studies using radiolabeled GM-CSF revealed that bull spermatozoa have about 105 high-affinity sites with a K(d) of 222 pM and approximately 1100 low-affinity sites with a K(d) of 10 nM. GM-CSF signaled, in a time- and dose-dependent manner, for an increased uptake of glucose and vitamin C.

Protective effect of seminal plasma proteins on the degradation of ascorbic acid

The objectives of this study were to determine ascorbic acid stability and its effect on antiproteinase activity of seminal plasma in the presence of an oxidant. Effect of seminal plasma, and additives: glutathione, albumin, hydrogen peroxide and Tris buffer, on ascorbic acid degradation was investigated by UV absorbance. Antiproteinase against trypsin amidase activity was measured spectrophotometrically using N-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. Ascorbic acid was destroyed much more rapidly with the addition of hydrogen peroxide than in Tris buffer at pH 8.2 alone. Seminal plasma protected ascorbic acid more efficiently than glutathione and albumin alone. The protective effect of seminal plasma on ascorbic acid degradation may closely relate to the function of ascorbic acid in reproductive system of scurvy-prone animals including teleost fish. Within the range of 1-8 mM concentrations, ascorbic acid had a pro-oxidant action on seminal plasma antiproteinase activity in vitro when they were incubated with hydrogen peroxide.

Ascorbic acid protects against endogenous oxidative DNA damage in human sperm

Damage to the DNA of germ cells can lead to mutation, which may result in birth defects, genetic diseases, and cancer. The very high endogenous rate of oxidative DNA damage and the importance of dietary ascorbic acid (AA) in preventing this damage has prompted an examination of these factors in human sperm DNA. The oxidized nucleoside 8-hydroxy-2'-deoxyguanosine (8-oxo-7,8-dihydro-2'-deoxyguanosine; oxo8dG), 1 of approximately 20 major products of oxidative damage to DNA, was measured in DNA isolated from human sperm provided by healthy subjects and compared to the seminal fluid AA levels. This relationship was studied in two groups. In a group of 24 free-living individuals 20-50 years old high levels of oxo8dG were correlated with low seminal plasma AA. The endogenous level of oxo8dG in this group was 13 fmol per microgram of DNA or approximately 25,000 adducts per sperm cell. The second group of individuals was maintained on a controlled diet that varied only in AA content. When dietary AA was decreased from 250 to 5 mg/day, the seminal fluid AA decreased by half and the level of oxo8dG in sperm DNA increased 91%. Repletion of dietary AA for 28 days (from 5 mg/day to 250 or 60 mg/day) caused a doubling in seminal fluid AA and reduced oxo8dG by 36%. These results indicate that dietary AA protects human sperm from endogenous oxidative DNA damage that could affect sperm quality and increase risk of genetic defects, particularly in populations with low AA such as smokers.