L- carnitine in idiopathic asthenozoospermia: a multicenter study

L-carnitine added to post-thawed semen acts as an antioxidant and a stimulator of equine sperm metabolism

The objective of this study was to enhance the in vitro sperm quality and in vivo fertility of frozen-thawed equine semen by the addition of l-carnitine (LC) to post-thawed semen. Different concentrations of LC were added to thawed samples to obtain four treatments control and 0.5, 1 and 2 mM LC. In the in vitro experiments, sperm motility and kinematics, membrane integrity and intracellular calcium ion concentration ([Ca²⁺ ]_i ) were investigated, and the antioxidant bioactivity of LC was assessed by measuring hydrogen peroxide and nitrite concentrations (NO₂ ^- ). The fertility rate was assessed via the artificial insemination of mares. The treatment with 1 mM LC increased sperm [Ca²⁺ ]_i (60.6 ± 0.05 AU), reduced nitrite concentration (39.1 ± 14.9 µM/µg protein), increased the sperm straightness percentage (STR: 78.3 ± 5.3%) and increased the pregnancy rate (75%) as compared to the control ([Ca²⁺ ]_i 48.4 ± 0.05 AU, NO₂ ^- concentration 63.1 ± 14.4 µM/µg protein, STR 67.5 ± 7.9%, 12.5% pregnancy rate, p < 0.05). These results suggest that 1 mM LC acts as an antioxidant and stimulator of sperm metabolism in post-thawed equine semen, increasing the fertility rate. Thus, addition of LC might be an alternative to improve the fertility of poor quality post-thawed equine semen.

Oxidative Stress and Male Fertility: Role of Antioxidants and Inositols

Infertility is defined as a couple’s inability to conceive after at least one year of regular unprotected intercourse. This condition has become a global health problem affecting approximately 187 million couples worldwide and about half of the cases are attributable to male factors. Oxidative stress is a common reason for several conditions associated with male infertility. High levels of reactive oxygen species (ROS) impair sperm quality by decreasing motility and increasing the oxidation of DNA, of protein and of lipids. Multi-antioxidant supplementation is considered effective for male fertility parameters due to the synergistic effects of antioxidants. Most of them act by decreasing ROS concentration, thus improving sperm quality. In addition, other natural molecules, myo-inositol (MI) and d-chiro–inositol (DCI), ameliorate sperm quality. In sperm cells, MI is involved in many transduction mechanisms that regulate cytoplasmic calcium levels, capacitation and mitochondrial function. On the other hand, DCI is involved in the downregulation of steroidogenic enzyme aromatase, which produces testosterone. In this review, we analyze the processes involving oxidative stress in male fertility and the mechanisms of action of different molecules.

Computational and Preclinical Evidence of Anti-ischemic Properties of L-Carnitine-Rich Supplement via Stimulation of Anti-inflammatory and Antioxidant Events in Testicular Torsed Rats

Ischemia-reperfusion injury is a urological emergency condition that could lead to necrosis, testicular damage subfertility, and infertility. The purpose of this study was to identify changes taking place in the rat testis at short-term (4 hr) as well as long-term (7 days) reperfusion following testicular torsion and to evaluate the effects of Proxeed Plus (PP), L-carnitine-rich antioxidant supplement, on preventing these changes using the biochemical parameters and histopathology. Thirty adult male rats were divided into five groups: in groups, 1-4 testicular ischemia was achieved by rotating the left testis 720° clockwise for 4 h and dividing into the sham, torsion/detorsion (T/D), T/D+1000 mg/kg BW PP, and T/D+5000 mg/kg BW PP groups, respectively. PP was administered intraperitoneally 30 min before detorsion while group 5 served as the normal control. All rats were sacrificed 4 h after detorsion. The same experimental design was set up, and animals were sacrificed after 7 days of detorsion. The testicular levels of human cyclooxygenase-2; tumor necrosis factor; interleukins-1β, 6, and 10; hydrogen peroxide; malonaldehyde; superoxide dismutase; catalase; glutathione transferase; glutathione peroxidase; glutathione reductase; and histopathological damage were evaluated. Our results revealed that rats in the torsion/detorsion group exhibited elevated testicular levels of oxidative markers and proinflammatory cytokines, low levels of antioxidant enzymes, and severe histological alterations relative to the control and sham groups. Treatments with 1000 and 5000 mg/kg BW of PP for 4 hr and 7 days significantly (p < 0.05) decreased the levels of the proinflammatory and oxidative markers while increasing the spermatogenesis, testicular levels of antioxidant enzymes, and anti-inflammatory cytokine (IL-10) in a dose-dependent manner. This suggested that PP exhibited anti-inflammatory and antioxidant activities against I/R testes thus serving as an effective supplement to protect against testicular assault.

Baseline levels of seminal reactive oxygen species predict improvements in sperm function following antioxidant therapy in men with infertility

BACKGROUND

Poor sperm function is a major cause of infertility. There is no drug therapy to improve sperm function. Semen oxidative stress is a recently identified pathway for sperm damage. Commercial antioxidants such as L-carnitine and acetyl-L-carnitine (LAL) are commonly self-administered by infertile men. However, concerns have been raised whether inappropriate LAL therapy causes reductive stress-mediated sperm damage. It is imperative to investigate whether: (1) LAL improves sperm function by reducing reactive oxidative species (ROS); (2) LAL has differential effects on sperm function between men with normal and elevated ROS.

METHODS

A prospective cohort study of routine clinical practice was performed in infertile men with abnormal sperm quality. Changes in sperm function and semen ROS levels following three months of oral LAL therapy were compared between participants with baseline seminal normal ROS (≤10RLU/SEC/10⁶ sperm; n = 29) and High ROS (>10 RLU/SEC/10⁶ sperm; n = 15) levels measured using an established colorimetric-luminol method.

RESULTS

In normal ROS group, sperm function did not change following LAL therapy. In high ROS group, LAL therapy reduced semen ROS fivefold, increased sperm count by 50% (mean count in mill/ml: 21.5 + 7.2, baseline; 32.6 + 9.5, post-treatment, P = .0005), and total and progressive sperm motility each by 30% (mean total sperm motility in % 29.8 + 5.0, baseline: 39.4 + 6.2, post-treatment, P = .004; mean progressive sperm motility in % 23.1 + 4.6, baseline: 30.0 + 5.5, post-treatment, P = .014 vs. baseline).

CONCLUSIONS

We report for the first time that LAL only improves sperm quality in infertile men who have baseline high-ROS levels prior to treatment. These data have important potential implications for couples with male infertility and their clinicians.

Current Insights and Latest Updates in Sperm Motility and Associated Applications in Assisted Reproduction

Spermatozoon is a motile cell with a special ability to travel through the woman’s reproductive tract and fertilize an oocyte. To reach and penetrate the oocyte, spermatozoa should possess progressive motility. Therefore, motility is an important parameter during both natural and assisted conception. The global trend of progressive reduction in the number and motility of healthy spermatozoa in the ejaculate is associated with increased risk of infertility. Therefore, developing approaches for maintaining or enhancing human sperm motility has been an important area of investigation. In this review we discuss the physiology of sperm, molecular pathways regulating sperm motility, risk factors affecting sperm motility, and the role of sperm motility in fertility outcomes. In addition, we discuss various pharmacological agents and biomolecules that can enhance sperm motility in vitro and in vivo conditions to improve assisted reproductive technology (ART) outcomes. This article opens dialogs to help toxicologists, clinicians, andrologists, and embryologists in understanding the mechanism of factors influencing sperm motility and various management strategies to improve treatment outcomes.

Polymeric Nanoparticle Versus Liposome Formulations: Comparative Physicochemical and Metabolomic Studies as L-Carnitine Delivery Systems

L-Carnitine has attracted much more attention especially in the treatment of crucial diseases such as diabetes, regional slimming, and obesity because of its metabolic activities. However, because of its short half-life, low bioavailability, and inability to be stored in the body, frequent dosing is required. In this study, L-carnitine-loaded liposome (lipo-carnitine) and PLGA nanoparticle (nano-carnitine) formulations were prepared and characterized. For lipo-carnitine and nano-carnitine formulations, particle size values were 97.88 ± 2.96 nm and 250.90 ± 6.15 nm; polydispersity index values were 0.35 ± 0.01 and 0.22 ± 0.03; zeta potential values were 6.36 ± 0.54 mV and - 32.80 ± 2.26 mV; and encapsulation efficiency percentage values were 14.26 ± 3.52% and 21.93 ± 4.17%, respectively. Comparative in vitro release studies of novel formulations and solution of L-carnitine revealed that L-carnitine released 90% of its content at the end of 1st hour. On the other hand, lipo-carnitine and nano-carnitine formulations maintained a controlled-release profile for 12 h. The in vitro efficacy of the formulations on cardiac fibroblasts (CFs) was evaluated by metabolomic studies and pathway analysis. Besides the prolonged release, lipo-carnitine/nano-carnitine formulations were also found to be effective on amino acid, carbohydrate, and lipid metabolisms. As a result, innovative nano-formulations were successfully developed as an alternative to conventional preparations which are available on the market.

Yishentongluo decoction in treatment of idiopathic asthenozoospermia infertility: Study protocol for a randomized controlled trial

BACKGROUND

The reproductive dilemma faced by men has always been the focus of the whole society. Idiopathic asthenozoospermia (AZS), as one of the common causes of male infertility, lack of specific treatment. Traditional Chinese medicine has shown potential benefits in the management of male infertility. Yishentongluo decoction (YSTL) is a representative Chinese herbal formula; however, there is still no rigorous clinical trial supporting its application. Therefore, we designed a randomized controlled trial to evaluate the efficacy and safety of YSTL for patients with idiopathic AZS and explain the possible action mechanisms of YSTL in improving sperm motility.

METHODS

In this randomized controlled study, a total of 160 eligible patients will be assigned to YSTL group or the Levocarnitine oral solution group in a 1:1 ratio. The treatment period will be 12 weeks and the follow-up period will last 4 weeks. The primary outcome will be the the progressive (motility), sperm rate (%). Secondary outcomes will include the progressive (motility) + non-progressive (motility) sperm rate(%), total effective sperm count, inner mitochondrial membrane potential (MMP) in spermatozoa, and spouse pregnancy rate (%). Safety outcomes will cover electrocardiogram , blood tests (including blood routine test, hepatic function, and renal function), urine routine test, and stool routine test. The semen parameters, sperm MMP test, and all the safety outcomes will be performed at the baseline, 4th, 8th and 12th week. The pregnancy outcome will be evaluated at 4 weeks after treatment.

DISCUSSION

This study will provide initial evidence regarding the efficacy and safety of YSTL in the treatment of idiopathic AZS with kidney deficiency and blood stasis pattern. In addition, potential mechanisms of YSTL in improving sperm motility will be explored based on sperm MMP test.

TRIAL REGISTRATION

Chinese Clinical Trials Register identifier, ChiCTR2000033290, registered on 26 May 2020.

Effect of L-carnitine on the expression of the apoptotic genes Bcl-2 and Bax

OBJECTIVE

The genes Bcl-2 and Bax play important roles in apoptosis. Many studies have shown that formalin has a strong deleterious effect on male fertility and can induce apoptosis. L-carnitine has been reported to potentially reverse the negative effects of formalin, leading to improved spermatogenesis. In this study, we examined the levels of expression of Bcl-2 and Bax in mice treated with formalin and L-carnitine.

METHODS

Thirty adult BALB/c mice were categorized into three groups. The mice in the control group (n=10) were not injected with any substance. The mice in the second group (n=10) received 10 mg/kg of formalin daily via an intraperitoneal injection, while those in the final group (n=10) were intraperitoneally injected daily with a dose of 10 mg/kg of formalin and 100 mg/kg of L-carnitine. All mice were kept in isolated cages for 31 days.

RESULTS

The expression of Bax was significantly higher in the formalin-treated mice than in the mice of the control group, while the expression of Bcl-2 was significantly lower in the formalin-treated mice than in the control mice. Additionally, relative to control mice, Bcl-2 expression increased and Bax expression decreased in the mice administered both formalin and L-carnitine.

CONCLUSION

In this study, L-carnitine was shown to augment Bcl-2 expression and to reduce Bax expression, indicating that this compound may inhibit apoptosis. Due to its positive effects, L-carnitine can be used as a prophylactic treatment for people who routinely come into direct contact with formalin as an occupational hazard.

Dietary supplementation with a novel l-carnitine multi-micronutrient in idiopathic male subfertility involving oligo-, astheno-, teratozoospermia: A randomized clinical study

OBJECTIVE

To study the influence of a multi-component nutrient dietary supplement on sperm parameters and pregnancy rates in idiopathic male infertility (IMI) with oligo-, astheno-, and teratozoospermia.

DESIGN

A randomized, double-blind, placebo-controlled, prospective, parallel arms (1:1 allocation ratio), multi-center clinical trial.

SETTINGS

Eight urology/reproductive health clinical centers located in Ukraine.

PATIENTS

Eighty-three males aged 21-50 years with IMI and at least 1 of 3 abnormal values: total sperm concentration < 15 million/ml or/and spermatozoa progressive motility < 32% or/and forms with normal morphology < 4%.

INTERVENTION(S)

Patients were randomly allocated verum test dietary supplement (TDS) containing l-carnitine/acetyl-l-carnitine, l-arginine, glutathione, co-enzyme Q10, zinc, vitamin B₉ , vitamin B₁₂ , selenium, or placebo 1 time daily for 6 months.

MAIN OUTCOME(S)

The primary outcome measure was the percentage of normal spermiograms (concentration ≥ 15 million/ml and ≥ 32% of spermatozoa with progressive motility and ≥ 4% of normal forms) at month 0, 2, and 4. The percentage of pregnancies served the secondary outcome endpoint. Differences between the groups were assessed in z-test for proportions.

RESULTS

All males finished the study. At month 4, 29/42 (69.0%) males in the verum and 9/41 (22.0%) had normal spermiograms (P < .001). The percentage of spontaneous pregnancies in the verum group was greater than in the placebo group (10/42, 23.8% vs. 2/41, 4.9%, respectively, P = .017). There were no reportable supplement-associated adverse events.

CONCLUSION

Specific multi-nutrient combination l-carnitine/l-acetyl-carnitine, l-arginine, glutathione, co-enzyme-Q, zinc, folic acid, cyanocobalamin, and selenium can improve sperm quality in males with IMI and increase pregnancy rates.

Mass Spectrometry Reveals New Insights into the Production of Superoxide Anions and 4-Hydroxynonenal Adducted Proteins in Human Sperm

The free-radical theory of male infertility suggests that reactive oxygen species produced by the spermatozoa themselves are a leading cause of sperm dysfunction, including loss of sperm motility. However, the field is overshadowed on several fronts, primarily because: i) the probes used to measure reactive oxygen species (ROS) are imprecise; and ii) many reports suggesting that oxygen radicals are detrimental to sperm function add an exogenous source of ROS. Herein, a more reliable approach to measure superoxide anion production by human spermatozoa based on MS analysis is used. Furthermore, the formation of the lipid-peroxidation product 4-hydroxynonenal (4-HNE) during in vitro incubation using proteomics is also investigated. The data demonstrate that neither superoxide anion nor other free radicals that cause 4-HNE production are related to the loss of sperm motility during incubation. Interestingly, it appears that many of the 4-HNE adducted proteins, found within spermatozoa, originate from the prostate. A quantitative SWATH analysis demonstrate that these proteins transiently bind to sperm and are then shed during in vitro incubation. These proteomics-based findings propose a revised understanding of oxidative stress within the male reproductive tract.

Poor Efficacy of L-Acetylcarnitine in the Treatment of Asthenozoospermia in Patients with Type 1 Diabetes

Introduction. In recent years, research has focused on the impact that diabetes mellitus (DM) has on male reproductive function. The available evidence has mainly considered type 2 DM (DM2). However, we have previously shown that type 1 DM (DM1) also affects male reproductive health. Given the efficacy of carnitine in the treatment of male infertility, a topic that merits further investigation is its role in the treatment of infertile patients with DM1. Aim. To investigate the efficacy of carnitines for the treatment of asthenozoospermia in DM1 patients. Methods. This was a two-arm single-blind, randomized control trial. The patients enrolled in this study were assigned to the group receiving L-acetylcarnitine (LAC) (1.5 g daily for 4 months) or to the group receiving LAC (same dosage) plus L-carnitine (LC) (2 g daily for 4 months). Serum-glycated hemoglobin levels did not differ significantly after either of the two treatments given. Administration of LAC plus LC showed greater efficacy on progressive sperm motility than single therapy (increase 14% vs. 1% after treatment, respectively). Discussion. The results of this study showed that the administration of LAC plus LC is more effective than the administration of LAC alone. The lower efficacy of LAC alone could be due to the lower overall administered dosage. Alternatively, a selective defect of carnitine transporters at an epididymal level could be hypothesized in patients with DM1. Further studies are needed to clarify this point.

Conservative Nonhormonal Options for the Treatment of Male Infertility: Antibiotics, Anti-Inflammatory Drugs, and Antioxidants

The nonhormonal medical treatment can be divided into empirical, when the cause has not been identified, and nonempirical, if the pathogenic mechanism causing male infertility can be solved or ameliorated. The empirical nonhormonal medical treatment has been proposed for patients with idiopathic or noncurable oligoasthenoteratozoospermia and for normozoospermic infertile patients. Anti-inflammatory, fibrinolytic, and antioxidant compounds, oligo elements, and vitamin supplementation may be prescribed. Infection, inflammation, and/or increased oxidative stress often require a specific treatment with antibiotics, anti-inflammatory drugs, and/or antioxidants. Combined therapies can contribute to improve sperm quality.

Does L-carnitine therapy add any extra benefit to standard inguinal varicocelectomy in terms of deoxyribonucleic acid damage or sperm quality factor indices: a randomized study

OBJECTIVE

To evaluate if addition of L-carnitine therapy to standard varicocelectomy adds any extra benefit in terms of improvement in semen parameters or deoxyribonucleic acid (DNA) damage.

MATERIALS AND METHODS

One hundred patients enrolled in this study and were randomly divided into 2 groups (50 patients in each group). In group 1, standard inguinal varicocelectomy and, in group 2, standard inguinal varicocelectomy plus oral antioxidant therapy (oral L-carnitine, 250 mg 3 times a day) were performed for 6 months. For all patients, routine semen analysis and DNA damage test of spermatozoa (by 2 methods of terminal deoxynucleotidyl transferase dUTP nick end labeling and protamine damage assay) were performed at baseline and at 3 and 6 months postoperatively.

RESULTS

In both groups, the improvement in semen analysis parameters and DNA damage was observed, but there was not any statistically significant difference between the 2 groups in these parameters, although the slope of improvement in DNA damage was slightly better in group 2 (that was not statistically significant).

CONCLUSION

We observed that addition of 750 mg of L-carnitine orally daily to standard inguinal varicocelectomy does not add any extra benefit in terms of improvement in semen analysis parameters or DNA damage.

Male infertility: non-surgical therapy

Infertility is defined as the inability of a couple to conceive after 12 months of unprotected intercourse and affects 15% of couples with male component of 50%. The failure of spermatogenesis can result from hypothalamic, pituitary or testicular disorders although in the majority of cases it remains idiopathic. The diagnostic process includes medical history, semen analysis, hormonal studies, genetic studies and radiological evaluation.

Targeted hormonal therapies are available for patients whose infertility is caused by altered levels of androgens, prolactin, or TSH. Main treatments aim to restore normal sexual function by administering testosterone and to increase spermatogenesis with pulsatile GnRH.

Fertility in men suffering from hypogonadotrophic hypogonadism can be restored through hormone therapy using GnRH or with the use of gonadotropins when there is hypothalamic failure. In the past, treatment options for the factors of idiopathic male infertility were mainly based on the use of anti-estrogens that cause an increased secretion of FSH and LH and therefore of testosterone.

Oxytocin promotes the progression of the sperm and increases the conversion of testosterone into dihydrotestosterone. The aromatase's inhibitors decrease the conversion of androgens to estrogens, increasing serum levels of androgens, resulting in an increased release of gonadotropins.

Two areas showed interesting future perspectives for the treatment of infertility: gene therapy and transplantation of spermatogonial stem cells.

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.

Medical therapy for spermatogenic failure

Medical treatment of men with primary spermatogenic failure remains largely ineffective in contrast to those with secondary testicular failure. Treatment has been attempted with a multitude of agents ranging from hormones to nutritional supplements (antioxidants). While some studies have demonstrated benefit to some treatments, no treatments have consistently demonstrated efficacy nor has it been possible to reliably identify patients likely to benefit. Idiopathic spermatogenic failure likely results from multiple discrete defects in sperm production that are as yet unidentified. A better understanding of these defects will yield more effective treatment options and appropriate triage of patients to specific therapeutic regimens. This review focuses on the rationale and current evidence for hormonal and antioxidant therapy in medical treatment of male infertility, spermatogenic failure in particular. Although empiric medical therapy for spermatogenic failure has been largely replaced by assisted reproductive techniques, both treatment modalities could play a role, perhaps as combination therapy.

The role of antioxidant therapy in the treatment of male infertility: an overview

In recent years, many studies have focused on the effect of oxidative stress, reactive oxygen species (ROS) and antioxidants on the male eproductive system. Under physiological conditions, sperm produces small amounts of ROS, which are needed for fertilisation, acrosome reaction and capacitation. However, if an increased production of ROS is not associated with a similar increase in scavenging systems, peroxidative damage of the sperm plasma membrane and loss of DNA integrity typically occur, which leads to cell death and reduced fertility. Furthermore, since there is no linear correlation between sperm quality and pregnancy rates, an improvement in semen parameters should not be the sole outcome considered in studies of antioxidant therapies. A definitive conclusion regarding the benefit of these therapies is difficult to obtain, as most of the previous studies lacked control groups, considered different antioxidants in different combinations and doses, or did not evaluate pregnancy rates in previously infertile couples. Even if beneficial effects were reported in a few cases of male infertility, more multicentre, double-blind studies performed with the same criteria are necessary for an increased understanding of the effects of various antioxidants on fertility.

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.

Contemporary concepts in the evaluation and management of male infertility

Infertility in men is a common condition. At the core of the medical evaluation of the male partner in a couple who are unable to conceive is the history and physical examination. Special attention should be directed to the patient's developmental history and any use of testosterone products. The physical examination focuses on the genitals, and includes assessments of the size and consistency of the testicles, epididymis, vas deferens, and presence of varicoceles. Although many sophisticated tests are available, semen analysis is still the most important diagnostic tool used to assess fertility, and includes parameters such as sperm count, motility and viability. Treatment of male factor infertility can involve targeted agents, in the case of specific conditions such as hypogonadotropic hypogonadism, or it can be empirical-using medical therapy or assisted conception techniques-for patients in whom no underlying cause has been identified. Although an all-encompassing treatment for male factor infertility has not yet been developed, the field offers many promising avenues of research.

Cadmium toxicity in spermatogenesis and protective effects of L-carnitine in adult male rats

In this study, the effects of cadmium toxicity and the protective effects of L-carnitine on spermatogenesis in Sprague-Dawley rat were evaluated. Animals were subdivided into five groups. Cadmium chloride (1-mg/kg body weight) was injected intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. L-carnitine (500 mg/kg b.w., IP) was pretreated in both of control and cadmium-injected rats. Animals were killed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank's balanced salt solution for evaluation of sperm count and viability. Following contamination with cadmium, a decrease in the number and viability of cauda epididymis sperm, the number of cell proliferation, and Johnsen Scores in the seminiferous tubules was observed. Consequently, L-carnitine treatment caused an increase in the number and viability of cauda epididymis sperm, the number of cell proliferation, and Johnsen Scores in the cadmium-induced group.

Effect of pentoxifylline on semen parameters, reproductive hormones, and seminal plasma antioxidant capacity in men with idiopathic infertility: a randomized double-blind placebo-controlled study

OBJECTIVE

To determine the safety and efficacy of oral pentoxifylline (PTX) administration in improving semen parameters in infertile men with idiopathic OAT.

PATIENTS AND METHODS

The study included 254 infertile men who underwent double-blind therapy with 400 mg PTX (Apotex Inc., Toronto, Canada) twice daily (group 1, n = 127), or similar regimen of placebo (group 2, n = 127). The study consisted of a 4-week screening phase, a 24-week treatment phase, and a 12-week treatment-free period. The effects of treatment on semen parameters, serum hormones including testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and inhibin B, seminal plasma catalase-like and superoxide dismutase (SOD)-like activity, and acrosome reaction test were evaluated.

RESULTS

A significant increase in sperm concentration (mean value, 26.4 ± 4.6 × 10(6)/ml vs. 16.2 ± 3.4 × 10(6)/ml), sperm motility (mean value, 35.8 ± 4.2% vs. 26.4 ± 2.4%), and sperm with normal morphology (mean value, 25.4 ± 4.3% vs. 17.4 ± 4.2%) was observed after PTX administration when compared with baseline (all P = 0.001); in contrast, a subtle decreased values were observed after placebo (median values, 16.4 ± 4.1 × 10(6)/ml vs. 16.7 ± 3.6 × 10(6)/ml, P = 0.1; 25.7 ± 3.6% vs. 26.8 ± 2.5%, P = 0.08; and 16.9 ± 4.1% vs. 17.6 ± 4.4%, P = 0.08, respectively). Mean SOD-like and catalase-like activity in the semen of PTX group was significantly greater than in the semen of placebo group (46.4 ± 2.4 vs. 36.3 ± 1.3 U/ml and 371 ± 44 vs. 301 ± 14 U/ml, respectively, both P = 0.003). The acrosome reaction was observed to be increased in PTX group (P = 0.01). Levels of reproductive hormones were also affected.

CONCLUSIONS

PTX administration significantly improves semen parameters in infertile men with idiopathic OAT.

Sperm proteins in teleostean and chondrostean (sturgeon) fishes

Sperm proteins in the seminal plasma and spermatozoa of teleostean and chondrostean have evolved adaptations due to the changes in the reproductive environment. Analysis of the composition and functions of these proteins provides new insights into sperm motility and fertilising abilities, thereby creating possibilities for improving artificial reproduction and germplasm resource conservation technologies (e.g. cryopreservation). Seminal plasma proteins are involved in the protection of spermatozoa during storage in the reproductive system, whereas all spermatozoa proteins contribute to the swimming and fertilising abilities of sperm. Compared to mammalian species, little data are available on fish sperm proteins and their functions. We review here the current state of the art in this field and focus on relevant subjects that require attention. Future research should concentrate on protein functions and their mode of action in fish species, especially on the role of spermatozoa surface proteins during fertilisation and on a description of sturgeon sperm proteins.

Antioxidant therapy in male infertility

Although reports have suggested the benefit of antioxidant treatment of infertile men, many studies also show no effect. Most studies in the literature are not randomized, placebo controlled, or double blinded in design, which makes it difficult to differentiate regression toward the mean from true positive treatment effects. The small patient sample sizes and varying male populations also add to the difficulty in comparing studies. Pregnancy, the most relevant outcome parameter, is rarely reported. Ideally, patients would be selected based on oxidative stress levels, and improvement in these levels would be correlated to improvement in pregnancy rates. Until those studies are performed, the use of antioxidants for the treatment of male infertility remains empiric.

Coenzyme Q10 treatment in infertile men with idiopathic asthenozoospermia: a placebo-controlled, double-blind randomized trial

OBJECTIVE

To evaluate the effectiveness of coenzyme Q(10) treatment in improving semen quality in men with idiopathic infertility.

DESIGN

Placebo-controlled, double-blind randomized trial.

SETTING

Andrology Unit, Department of Internal Medicine, Polytechnic University of Marche, Italy.

PATIENT(S)

Sixty infertile patients (27-39 years of age) with the following baseline sperm selection criteria: concentration >20 x 10(6)/mL, sperm forward motility <50%, and normal sperm morphology >30%; 55 patients completed the study.

INTERVENTION(S)

Patients underwent double-blind therapy with coenzyme Q(10), 200 mg/day, or placebo; the study design was 1 month of run-in, 6 months of therapy or placebo, and 3 months of follow-up.

MAIN OUTCOME MEASURE(S)

Variations in semen parameters used for patient selection and variations of coenzyme Q(10) and ubiquinol concentrations in seminal plasma and spermatozoa.

RESULT(S)

Coenzyme Q(10) and ubiquinol increased significantly in both seminal plasma and sperm cells after treatment, as well as spermatozoa motility. A weak linear dependence among the relative variations, baseline and after treatment, of seminal plasma or intracellular coenzyme Q(10) and ubiquinol levels and kinetic parameters was found in the treated group. Patients with a lower baseline value of motility and levels of coenzyme Q(10) had a statistically significant higher probability to be responders to the treatment.

CONCLUSION(S)

The exogenous administration of coenzyme Q(10) increases the level of the same and ubiquinol in semen and is effective in improving sperm kinetic features in patients affected by idiopathic asthenozoospermia.

Drug Therapy for Idiopathic Male Infertility: Rationale Versus Evidence

PURPOSE

About half of all infertile men who seek treatment have no specific cause that can be determined for the seminal abnormality. These men are often subject to a number of medical therapies with doubtful efficacy. We reviewed the rationale on which these therapies are advised and determined whether sufficient medical evidence exists to justify their use.

MATERIALS AND METHODS

A literature search was performed using MEDLINE/PubMed, focusing on publications of the last 20 years of drug therapies for idiopathic male factor infertility. Therapies for specific abnormalities such as hypogonadism were excluded. Basic science, in vitro and animal studies suggesting the mechanism of action for male infertility were evaluated as the rationale part of the review, while controlled and uncontrolled human clinical trials were reviewed as evidence for drug use.

RESULTS

There is no evidence in support of androgens and gonadotropins for enhancing male fertility. These agents may instead act as contraceptives with significant side effects. There is insufficient evidence regarding the role of antiestrogens, aromatase inhibitors and antioxidants. No drug therapy has proved to be clearly beneficial for idiopathic oligoasthenoteratospermia.

CONCLUSIONS

Drug therapy for idiopathic male infertility is at best empirical. There is no clear benefit of using any medication in these patients. Moreover, androgens should not be used because they may actually suppress spermatogenesis.

Carnitine for the treatment of idiopathic asthenospermia: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To determine the effect of oral carnitine supplementation on the semen parameters of men with idiopathic asthenospermia.

DESIGN

Prospective, randomized, double-blind placebo-controlled study.

SETTING

Academic tertiary referral centers.

PATIENT(S)

Male patients presenting with infertility and with sperm motility of 10%-50% were selected.

INTERVENTION(S)

Patients were randomized to 24-week treatment arms of oral carnitine (2,000 mg L-carnitine and 1,000 mg L-acetyl-carnitine per day) or placebo.

MAIN OUTCOME MEASURE(S)

Sperm motility and total motile sperm counts at baseline, 12 weeks, and 24 weeks. Seminal plasma and sperm free, acetyl, and total L-carnitine levels at baseline and at week 24.

RESULT(S)

Twenty-one patients entered the study, with 12 patients in the carnitine arm and 9 in the placebo arm. There were no significant differences in baseline semen parameters between the carnitine and placebo arms. There was no statistically significant or clinically significant increase in motility or total motile sperm counts between baseline, 12 week, or 24 weeks in the carnitine or placebo arms.

CONCLUSION(S)

Carnitine supplementation demonstrated no clinically or statistically significant effect on sperm motility or total motile sperm counts in men with idiopathic asthenospermia.

Placebo-controlled double-blind randomized trial on the use of L-carnitine, L-acetylcarnitine, or combined L-carnitine and L-acetylcarnitine in men with idiopathic asthenozoospermia

OBJECTIVE

To evaluate the effectiveness of L-carnitine (LC) or L-acetyl-carnitine (LAC) or combined LC and LAC treatment in improving semen kinetic parameters and the total oxyradical scavenging capacity in semen.

DESIGN

Placebo-controlled, double-blind, randomized trial.

SETTING

Andrology unit, Department of Internal Medicine, Polytechnic University of Marche, Italy.

PATIENT(S)

Sixty infertile men, ages 20 to 40 years, with the following baseline sperm selection criteria: concentration > 20 x 10(6)/mL, sperm forward motility < 50%, and normal sperm morphology > 30%; 59 patients completed the study.

INTERVENTION(S)

Patients underwent a double-blind therapy of LC 3 g/d, LAC 3 g/d, a combination of LC 2 g/d and LAC 1 g/d, or placebo. The study design was 1 month of run in, 6 months of therapy or placebo, and 3 months of follow-up evaluation.

MAIN OUTCOME MEASURE(S)

Variations in semen parameters used for patient selection, and variations in total oxyradical scavenging capacity of the seminal fluid.

RESULT(S)

Sperm cell motility (total and forward, including kinetic features determined by computer-assisted sperm analysis) increased in patients to whom LAC was administered both alone or in combination with LC; combined LC + LAC therapy led to a significant improvement of straight progressive velocity after 3 months. The total oxyradical scavenging capacity of the semen toward hydroxyl and peroxyl radicals also increased and was positively correlated with the improvement of kinetic features. Patients with lower baseline values of motility and total oxyradical scavenging capacity of the seminal fluid had a significantly higher probability of responding to the treatment.

CONCLUSION(S)

The administration of LC and LAC is effective in increasing sperm kinetic features in patients affected by idiopathic asthenozoospemia and improves the total oxyradical scavenging capacity of the seminal fluid in the same population.

Correlation between seminal carnitine and functional spermatozoal characteristics in men with semen dysfunction of various origins

BACKGROUND AND OBJECTIVE

L-carnitine is an essential molecule involved in mitochondrial metabolism, controlling the transport of acetyl and acyl groups across the mitochondrial inner membrane. Carnitine and acetylated carnitine (L-acetylcarnitine) are found in high concentrations in the epididymis, where they also act as antioxidants, protecting spermatozoa against damage caused by reactive oxygen species. In this open study we investigated the correlation between seminal carnitine levels and spermatozoal function, and the effect of combined L-carnitine + L-acetylcarnitine therapy, in infertile men.

PATIENTS AND METHODS

170 infertile men were enrolled in this study. Patients were divided into those with a total sperm motility below the normal WHO range (<50% motility, group 1 [n = 102]) and those with total sperm motility within the normal range (> or =50% motility, group 2 [n = 68]). Patients in group 1 were further divided into two groups: those with primary or secondary azoospermia (1B [n = 36]), and those without (1A [n = 66]). Patients in group 1A received L-carnitine 1 g/day and L-acetylcarnitine 500 mg twice daily for 6 months. Seminal carnitine levels were measured and correlated with sperm count and motility, eosin test, hypo-osmotic swelling test, acridine orange test for sperm nuclear DNA integrity and sperm kinetics evaluated by computer-assisted sperm analysis in all patients.

RESULTS

There was a significant correlation between seminal carnitine concentration and sperm concentration, total sperm count, sperm total motility, rapid forward progression, live sperm count, membrane function, nuclear DNA integrity, capacity for cervical mucus penetration, linearity of spermatic movement, and amplitude of lateral sperm head movement (all p < 0.0001) in the entire study population. In group 1A, there was a significant increase in total motility, live sperm count, membrane integrity and linearity of spermatic movement after 3 and 6 months of L-carnitine/L-acetylcarnitine treatment, and in capacity for cervical mucus penetration after 6 months of treatment, compared with baseline.

CONCLUSION

Seminal carnitine concentration may be an appropriate marker of sperm and epididymal function. L-carnitine/L-acetylcarnitine treatment may be an effective therapy to improve mainly functional seminal parameters.

The Role of Carnitine in the Male Reproductive System

Carnitine is highly concentrated in the epididymis and spermatozoa, where it may serve as an intramitochondrial vehicle for the acyl group, which in the form of acyl CoA acts as a substrate for the oxidation process producing energy for sperm respiration and motility. To date, studies in rodents and humans suggest that sperm count, motility, and maturation are related to epididymal free carnitine concentrations. Moreover, supplementation with carnitine improves sperm quality and/or quantity in testes of mice exposed to physical insults, such as heat and X-irradiation, and in men with idiopathic oligoasthenospermia. These benefits may be due to increased mitochondrial fatty acid oxidation resulting in improvement in motility of epididymal sperm. The antiapoptotic effect(s) of carnitine in the testes may also contribute, but this remains speculative and requires further investigation. Research to uncover the many characteristics and mechanisms of action of carnitine in somatic and germ cells may provide insights into the pathophysiology of germ cell apoptosis, the prevention of germ cell death, and possibly specific therapy of some forms of infertility. Further well-controlled, carefully designed, larger-scale studies are necessary and desirable before widespread clinical use as an infertility therapy can be contemplated.

Effect of L-carnitine administration on the seminal characteristics of oligoasthenospermic stallions

The effect of orally administered l-carnitine on the quality of semen obtained from stallions with different semen qualities was investigated. Four stallions with proven fertility (high motility group, HM) and with normal seminal characteristics (>50% progressive motility and > 80 x 10(6) spermatozoa/ml), and four questionable breeders (low motility group, LM) with <50% of sperm progressive motility and < 80 x 10(6) spermatozoa/ml, received p.o. 20 g of l-carnitine for 60 days. Blood and semen samples were collected before treatment (T0) and after 30 (T1) and 60 days (T2). Semen evaluation were performed on five consecutive daily ejaculates (n = 120 ejaculates) and conventional semen analysis was carried out on each ejaculate, both at collection and after refrigeration for 24, 48, and 72 h. Furthermore l-carnitine, acetylcarnitine, pyruvate, and lactate concentrations, and carnitine acetyltransferase activity (CAT) were determined both in raw semen and seminal plasma. There were an increase in progressive motile spermatozoa only in the LM group (26.8 +/- 12.9, 39.1 +/- 15.5, and 48.8 +/- 8.6 for T0, T1, and T2, respectively). Free seminal plasma carnitine concentration was higher in the LM group compared to the HM one. Both pyruvate and lactate were higher in the LM group. Raw semen and seminal plasma carnitine and acetylcarnitine levels correlate positively with both sperm concentration and progressive motility; moreover, acetylcarnitine content was positively correlated with total motile morphologically normal spermatozoa. In conclusion, oral administration of l-carnitine to stallions with questionable seminal characteristics may improve spermatozoa kinetics and morphological characteristics; whereas, it seem to be ineffective in normospermic animals.

A placebo-controlled double-blind randomized trial of the use of combined l-carnitine and l-acetyl-carnitine treatment in men with asthenozoospermia

OBJECTIVE

To determine the efficacy of combined l-carnitine and l-acetyl-carnitine therapy in infertile males with oligo-astheno-teratozoospermia.

DESIGN

Placebo-controlled double-blind randomized trial.

SETTING

University tertiary referral center.

PATIENT(S)

Sixty infertile patients (aged 20-40 years) with the following baseline sperm selection criteria: concentration, 10 to 40 x 10(6)/mL; forward motility, <15%; total motility, 10% to 40%; and atypical forms, <80%. Fifty-six patients completed the study.

INTERVENTION(S)

Patients were submitted to a combined treatment of l-carnitine (2 g/d) and l-acetyl-carnitine (1 g/d) or of placebo; the study design was 2 months' wash-out, 6 months of therapy or of placebo, and 2 months' follow-up.

MAIN OUTCOME MEASURE(S)

Variation in the semen parameters that were used for patient selection.

RESULT(S)

Even though increases were seen in all sperm parameters after combined carnitine treatment, the most significant improvement in sperm motility (both forward and total) was present in patients who had lower initial absolute values of motile sperm (<4 x 10(6) forward or <5 x 10(6) total motile spermatozoa per ejaculate).

CONCLUSION(S)

Combined treatment with l-carnitine and l-acetyl-carnitine in a controlled study of efficacy was effective in increasing sperm motility, especially in groups with lower baseline levels.

Role of antioxidants in treatment of male infertility: an overview of the literature

Seminal oxidative stress in the male reproductive tract is known to result in peroxidative damage of the sperm plasma membrane and loss of its DNA integrity. Normally, a balance exists between concentrations of reactive oxygen species and antioxidant scavenging systems. One of the rational strategies to counteract the oxidative stress is to increase the scavenging capacity of seminal plasma. Numerous studies have evaluated the efficacy of antioxidants in male infertility. In this review, the results of different studies conducted have been analysed, and the evidence available to date is provided. It was found that although many clinical trials have demonstrated the beneficial effects of antioxidants in selected cases of male infertility, some studies failed to demonstrate the same benefit. The majority of the studies suffer from a lack of placebo-controlled, double-blind design, making it difficult to reach a definite conclusion. In addition, investigators have used different antioxidants in different combinations and dosages for varying durations. Pregnancy, the most relevant outcome parameter of fertility, was reported in only a few studies. Most studies failed to examine the effect of antioxidants on a specific group of infertile patients with high oxidative stress. Multicentre, double-blind studies with statistically accepted sample size are still needed to provide conclusive evidence on the benefit of antioxidants as a treatment modality for patients with male infertility.