Cadmium concentrations in blood and seminal plasma: correlations with sperm number and motility in three male populations (infertility patients, artificial insemination donors, and unselected volunteers)

Association of urinary metal element with semen quality: a cross-sectional study from Eastern China

The effect of metallic elements on semen quality remains controversial, with limited evidence on the effects of metal mixtures. We conducted a study involving 338 participants from multiple centers in Eastern China, measuring 17 urinary metals and semen quality parameters. Our analysis used various statistical models, including multivariate logistic and linear regression, Bayesian Kernel Machine Regression, and weighted quantile sum models, to examine the associations between metal levels and semen quality. Logistic regression showed that higher urinary lead was associated with increased risk of abnormal sperm concentration (OR = 1.86, p = 0.021), arsenic to higher abnormal progressive motility risk (OR = 1.49, p = 0.027), and antimony to greater abnormal total motility risk (OR = 1.37, p = 0.018). Conversely, tin was negatively correlated with the risk of abnormal progressive motility (OR = 0.76, p = 0.012) and total motility (OR = 0.74, p = 0.003), respectively. Moreover, the linear models showed an inverse association between barium and sperm count, even after adjusting for other metals (β = - 0.32, p < 0.001). Additionally, the WQS models showed that the metal mixture may increase the risk of abnormal total motility (βWQS = 0.55, p = 0.046). In conclusion, semen quality may be adversely affected by exposure to metals such as arsenic, barium, lead, and antimony. The combined effect of the metal mixture appears to be particularly impaired total motility.

The effects of repeated freezing and thawing on bovine sperm morphometry and function

Refreezing the remaining genetic resources after in vitro fertilization (IVF) can conserve genetic materials. However, the precise damage inflicted by repeated freezing and thawing on bovine sperm and its underlying mechanism remain largely unexplored. Thus, this study investigates the impact of repeated freeze-thaw cycles on sperm. Our findings indicate that such cycles significantly reduce sperm viability and motility. Furthermore, the integrity of the sperm plasma membrane and acrosome is compromised during this process, exacerbating the advanced apoptosis triggered by oxidative stress. Additionally, transmission electron microscopy exposed severe damage to the plasma membranes of both the sperm head and tail. Notably, the "9 + 2" structure of the tail was disrupted, along with a significant decrease in the level of the axonemal protein DNAH10, leading to reduced sperm motility. IVF outcomes revealed that repeated freeze-thaw cycles considerably impair sperm fertilization capability, ultimately reducing the blastocyst rate. In summary, our research demonstrates that repeated freeze-thaw cycles lead to a decline in sperm viability and motility, attributed to oxidative stress-induced apoptosis and DNAH10-related dynamic deficiency. As a result, the utility of semen is compromised after repeated freezing.

Investigation of the Effect of Hafnium Chloride on Sperm Viability and Motility in Normospermic Cases: An In Vitro Study

INTRODUCTION

Hafnium alloys are employed in medical applications due to their biocompatibility and high corrosion resistance. These alloys have demonstrated osteogenic and antimicrobial activities in surgical implants and have been utilized in the treatment of sarcoma. Additionally, a sensor based on hafnium nanoparticles has been reported for the detection of coronavirus disease 2019. Despite the increasing usage of hafnium, a literature review reveals no studies examining its effects on sperm in both human and animal species.

METHODS

Semen samples were analyzed according to the 2010 World Health Organization (WHO) criteria, and 20 normospermic specimens were included in the study. Three groups were formed: control, hafnium chloride 2 mg/mL, and 4 mg/mL. Motility and viability were assessed in all groups at the 20th and 40th minutes.

RESULTS

The decrease in viable sperm count was found to be significant in the 2 mg/ml HfCl4 group (difference: 12.73 ± 0.8, p<0.001) and the 4 mg/ml HfCl4 group (difference: 41.72 ± 1.34, p<0.001) compared to the control group. A time-dependent decrease in sperm viability was significant across all groups (difference: 8.93 ± 0.59, p<0.001). The decrease in viable sperm count in the 4 mg/ml HfCl4 group was significant when compared to the 2 mg/ml HfCl4 group (difference: 29 ± 1.27, p<0.001). The decrease in total motile sperm count was observed in both the 2 mg/ml HfCl4 group (difference: 12.80 ± 1.30, p<0.001) and the 4 mg/ml HfCl4 group (difference: 35.63 ± 1.12, p<0.001) compared to the control group. Additionally, the decrease in total motile sperm count in the 4 mg/ml HfCl4 group was significant compared to the 2 mg/ml HfCl4 group (difference: 22.80 ± 1.60, p<0.001). A time-dependent decrease in total motile sperm count was also significant (difference: 6.03 ± 0.49, p<0.001).

CONCLUSION

The study determined that hafnium chloride negatively affects sperm motility and viability in vitro. These effects may be due to the presence of an acidic environment. It has been demonstrated that instruments containing this element may pose a potential risk.

Melatonin counteracts cadmium-induced rat testicular toxicity via the mechanistic target rapamycin (mTOR) pathway

The protective action of melatonin (MLT) against the harmful effects of cadmium (Cd) on testicular activity in rats has been documented previously; however, the involved molecular mechanisms have yet to be elucidated. Herein, we investigate the involvement of the mammalian target of rapamycin (mTOR) on the ability of MLT to counteract the damage induced by Cd on the rat testicular activity. Our study confirmed that Cd has harmful effects on the testes of rats and the protective action exerted by MLT. We reported, for the first time, that the addition of rapamycin (Rapa), a specific mTOR inhibitor, to animals co-treated with Cd and MLT completely abolished the beneficial effects exerted by MLT, indicating that the mTOR pathway partially modulates its helpful effects on Cd testicular toxicity. Interestingly, Rapa-alone treatment, provoking mTOR inhibition, produced altered morphological parameters, increased autophagy of germ and somatic cells, and reduced serum testosterone concentration. In addition, mTOR inhibition also reduced protein levels of markers of steroidogenesis (3β-Hydroxysteroid dehydrogenase) and blood-testis barrier integrity (occludin and connexin 43). Finally, Rapa altered sperm parameters as well as the ability of mature spermatozoa to perform a proper acrosome reaction. Although further investigation is needed to better clarify the molecular pathway involved in MLT action, we confirm that MLT alleviating Cd effects can be used as a supplement to enhance testicular function and improve male gamete quality.

Assessing preconception exposure to environmental chemicals and fecundity: Strategies, challenges, and research priorities

In 2022, approximately one out of six people globally experienced infertility at some point in their life. Environmental chemicals, particularly those with endocrine disrupting activity, may contribute to impaired fecundity and infertility. We review existing prospective cohort studies of environmental chemicals and fecundity, identify methodological challenges and biases, and outline future research priorities. Studies of preconception environmental chemical exposures and fecundity have occurred in US, Singapore, China and Denmark with recruitment as early as 1982-1986, as recent as 2015-2017 and sample sizes ranging from 99 to 936. Higher exposure to certain chemicals (e.g. heavy metals, perfluoroalkyl substances) was associated with longer time to pregnancy; yet the literature is scarce or nonexistent for many chemicals. Furthermore, prospective studies face challenges and potential biases related to recruiting participants prior to conception, measuring environmental chemicals during critical windows of exposure, and ascertaining when pregnancy occurred. Research priorities include expanding the scope of biomonitoring data collected during the preconception period, continuing to develop and validate analytic methods for self-sampled biospecimens in traditional and novel matrices, collecting data in male partners and investigating etiologic associations according to indicators of marginalization.

A systematic review identifying seminal plasma biomarkers and their predictive ability on IVF and ICSI outcomes

The diverse nature and high molecule concentration of seminal plasma (SP) makes this fluid a good potential source for a potential biomarker that could predict assisted reproductive technology (ART) outcomes. Currently, semen quality parameters cannot accurately predict ART outcomes. A systematic literature search was conducted to identify human SP biomarkers with potential predictive ability for the outcomes of IVF and intracytoplasmic sperm injection. Observational cohort and case-control studies describing the association between biomarkers in human SP and the outcome of infertile men attending for ART were included. Forty-three studies were selected, reporting on 89 potential SP biomarkers (grouped as oxidative stress, proteins glycoproteins, metabolites, immune system components, metals and trace elements and nucleic acids). The present review supports 32 molecules in SP as potentially relevant biomarkers for predicting ART outcomes; 23 molecules were reported once and nine molecules were reported in more than one study; IL-18 and TGF-β1-IL-18 ratio were confirmed in distinct studies. This review presents the most comprehensive overview of relevant SP biomarkers to predict ART outcomes to date, which is of clinical interest for infertility investigations and assisted reproduction; nevertheless, its potential is under-exploited. This review could serve as starting point for designing an all-encompassing study for biomarkers in SP and their predictive ability for ART outcomes, and for developing a non-invasive diagnostic tool.

The crosstalk between telomeres and DNA repair mechanisms: an overview to mammalian somatic cells, germ cells, and preimplantation embryos

Telomeres are located at the ends of linear chromosomes and play a critical role in maintaining genomic stability by preventing premature activation of DNA repair mechanisms. Because of exposure to various genotoxic agents, telomeres can undergo shortening and genetic changes. In mammalian cells, the basic DNA repair mechanisms, including base excision repair, nucleotide excision repair, double-strand break repair, and mismatch repair, function in repairing potential damages in telomeres. If these damages are not repaired correctly in time, the unfavorable results such as apoptosis, cell cycle arrest, and cancerous transition may occur. During lifespan, mammalian somatic cells, male and female germ cells, and preimplantation embryos experience a number of telomeric damages. Herein, we comprehensively reviewed the crosstalk between telomeres and the DNA repair mechanisms in the somatic cells, germ cells, and embryos. Infertility development resulting from possible defects in this crosstalk is also discussed in the light of existing studies.

Urinary metal profiles in mother-offspring pairs and their association with early dysglycemia in the International Hyperglycemia and Adverse Pregnancy Outcome Follow Up Study (HAPO-FUS)

BACKGROUND

Variations in dietary intake and environmental exposure patterns of essential and non-essential trace metals influence many aspects of human health throughout the life span.

OBJECTIVE

To examine the relationship between urine profiles of essential and non-essential metals in mother-offspring pairs and their association with early dysglycemia.

METHODS

Herein, we report findings from an ancillary study to the international Hyperglycemia and Adverse Pregnancy Outcome Follow-Up Study (HAPO-FUS) that examined urinary essential and non-essential metal profiles from mothers and offspring ages 10-14 years (1012 mothers, 1013 offspring, 968 matched pairs) from 10 international sites.

RESULTS

Our analysis demonstrated a diverse exposure pattern across participating sites. In multiple regression modelling, a positive association between markers of early dysglycemia and urinary zinc was found in both mothers and offspring after adjustment for common risk factors for diabetes. The analysis showed weaker, positive, and negative associations of the 2-h glucose value with urinary selenium and arsenic respectively. A positive association between 2-h glucose values and cadmium was found only in mothers in the fully adjusted model when participants with established diabetes were excluded. There was a high degree of concordance between mother and offspring urinary metal profiles. Mother-to-offspring urinary metal ratios were unique for each metal, providing insights into changes in their homeostasis across the lifespan.

SIGNIFICANCE

Urinary levels of essential and non-essential metals are closely correlated between mothers and their offspring in an international cohort. Urinary levels of zinc, selenium, arsenic, and cadmium showed varying degrees of association with early dysglycemia in a comparatively healthy cohort with a low rate of preexisting diabetes.

IMPACT STATEMENT

Our data provides novel evidence for a strong correlation between mother and offspring urinary metal patterns with a unique mother-to-offspring ratio for each metal. The study also provides new evidence for a strong positive association between early dysglycemia and urinary zinc, both in mothers and offspring. Weaker positive associations with urinary selenium and cadmium and negative associations with arsenic were also found. The low rate of preexisting diabetes in this population provides the unique advantage of minimizing the confounding effect of preexisting, diabetes related renal changes that would alter the relationship between dysglycemia and renal metal excretion.

Environmental and occupational exposure to cadmium associated with male reproductive health risk: a systematic review and meta-analysis based on epidemiological evidence

There is an abundance of epidemiological evidence and animal experiments concerning the correlation between cadmium exposure and adverse male reproductive health outcomes. However, the evidence remains inconclusive. We conducted a literature search from PubMed, Embase, and Web of Science over the past 3 decades. Pooled r and 95% confidence intervals (CIs) were derived from Cd levels of the type of biological materials and different outcome indicators to address the large heterogeneity of existing literature. Cd was negatively correlated with semen parameters (r = - 0.122, 95% CI - 0.151 to - 0.092) and positively correlated with sera sex hormones (r = 0.104, 95% CI 0.060 to 0.147). Among them, Cd in three different biological materials (blood, semen, and urine) was negatively correlated with semen parameters, while among sex hormones, only blood and urine were statistically positively correlated. In subgroup analysis, blood Cd was negatively correlated with semen density, sperm motility, sperm morphology, and sperm count. Semen Cd was negatively correlated with semen concentration. As for serum sex hormones, blood Cd had no statistical significance with three hormones, while semen Cd was negatively correlated with testosterone. In summary, cadmium exposure might be associated with the risk of a decline in sperm quality and abnormal levels of sex hormones.

Microplastics: unraveling the signaling pathways involved in reproductive health

Microplastics (MPs) are biologically active environmental pollutants having significant impact on the ecosystem and human health. MPs have been reported to increase oxidative stress, resulting in tissue damage, developmental abnormalities, metabolic disorders, epigenetic changes, abnormal reproduction, and reduced gamete quality. At present, most of the existing literature has focused on the effects of MPs on the reproduction of various aquatic organisms; however, the effects of MPs on mammalian reproduction specifically humans are least studied except a few ones fragmentally discussing the effects of MPs on gametogenesis in human. This review discusses effects of MPs on male and female reproduction with a focus on different metabolic pathways involved in compromised gamete quality, gamete toxicity, apoptosis, and DNA damage.

Cadmium and lead implication in testis cancer; is there a connection?

Testis cancer (TC) is the most common malignancy of young men. Current evidence from studies, alongside genetics and hormonal status, suggests a significant role of toxic metals, cadmium (Cd) and lead (Pb), in the origin and development of TC. Besides oxidative stress and endocrine disruption, interaction with bioelements is one of the critical mechanisms of Cd and Pb toxicity and malign transformation. This study aimed to investigate metal levels in blood, healthy, and tumor testis tissue and to reveal hormone, oxidative status, and bioelements levels in patients with TC. The study enrolled 52 patients with TC and 61 healthy volunteers. Toxic metals and bioelements levels were analyzed by atomic absorption spectrophotometry (AAS) while electrochemiluminescence immunoassay (ECLIA) and spectrophotometry methods were used for hormone and oxidative parameters evaluation. Significantly higher blood Cd levels were depicted in TC cohort. Furthermore, blood Cd elevation was associated with a 1.98 higher probability of TC developing. However, a metal concentration between healthy and tumor testis tissue did not differ significantly. Lower levels of estradiol and testosterone, established in a cohort of TC patients, followed the significant role of hormones in TC development. At the same time, ischemia-modified albumin (IMA) has been recognized as a parameter with very good accuracy as a potential diagnostic marker for TC. The study revealed different distribution patterns of copper (Cu) and zinc (Zn) in the three compartments of the patients, as well significant correlation between essential metals Cu/Zn and toxic metals Cd/Pb indicating metal-metal interactions as pivotal mechanisms of metals toxicity.

Evidence of the protective role of D-Aspartate in counteracting/preventing cadmium-induced oxidative stress in the rat testis

Cadmium (Cd), by producing oxidative stress and acting as an endocrine disruptor, is known to cause severe testicular injury, documented by histological and biomolecular alterations, such as decreased serum testosterone (T) level and impairment of spermatogenesis. This is the first report on the potential counteractive/preventive action of D-Aspartate (D-Asp), a well-known stimulator of T biosynthesis and spermatogenesis progression by affecting hypothalamic-pituitary-gonadal axis, in alleviating Cd effects in the rat testis. Our results confirmed that Cd affects testicular activity, as documented by the reduction of serum T concentration and of the protein levels of steroidogenesis (StAR, 3β-HSD, and 17β-HSD) and spermatogenesis (PCNA, p-H3, and SYCP3) markers. Moreover, higher protein levels of cytochrome C and caspase 3, together with the number of cells positive to TUNEL assay, indicated the intensification of the apoptotic process. D-Asp administered either simultaneously to Cd, or for 15 days before the Cd-treatment, reduced the oxidative stress induced by the metal, alleviating the consequent harmful effects. Interestingly, the preventive action of D-Asp was more effective than its counteractive effect. A possible explanation is that giving D-Asp for 15 days induces its significant uptake in the testes, reaching the concentrations necessary for optimum function. In summary, this report highlights, for the first time, the beneficial role played by D-Asp in both counteracting/preventing the adverse Cd effects in the rat testis, strongly encouraging further investigations to consider the potential value of D-Asp also in improving human testicular health and male fertility.

Retrograde sclerotherapy of male varicocele with veno-venous shunts - incidence and management: a single-centre experience

OBJECTIVES

The aim of our study is to compare the incidence of veno-venous shunts in male varicocele and evaluate the possibility to exclude them with manual compression or/and scrotal ligation in order to carry out the procedure of retrograde sclero-embolization.

METHODS

In our retrospective study, all patients undergone retrograde sclerotherapy for varicocele in our Interventional Radiology Unit in the last four years were evaluated. Collaterals toward other venous shunts were identified and how many and which patients would be able to complete the procedure safely were considered.

RESULTS

Of the 91 patients, as many as 22 (i.e., 24.17%) patients presented anatomical variants, consisting on shunting into left iliac vein (9 [9.89%]), lumbar left veins (3 [3.29%]), right iliac vein (1 [1.09%]), both iliac veins (1 [1.09%]), left femoral vein (1 [1.09%]) or a more proximal portion of the ISV itself without shunting (3 [3.29%]). Patients with duplication could benefit from a more distal injection in order to prevent back-flow; of the 19 left, nine successfully underwent sclerotherapy with manual compression or/and scrotal ligation, whereas in 10 flow through the collaterals could not be interrupted and patients were demanded for surgery.

CONCLUSIONS

Many patients with abnormal communications between the internal spermatic vein and the iliac veins (that is, shunts towards the iliac veins) may as well undergo retrograde sclerotherapy safely if compression/ligation is applied.

ADVANCES IN KNOWLEDGE

No large previous study highlighted the impact of veno-venous shunts in technical feasibility of retrograde sclerotherapy of varicocele.

Mechanisms of Cadmium-Induced Testicular Injury: A Risk to Male Fertility

Cadmium is a heavy toxic metal with unknown biological functions in the human body. Over time, cadmium accretion in the different visceral organs (liver, lungs, kidney, and testis) is said to impair the function of these organs, which is associated with a relatively long biological half-life and a very low rate of excretion. Recently studies have revealed that the testes are highly sensitive to cadmium. In this review, we discussed the adverse effect of cadmium on the development and biological functions of the testis. The Sertoli cells (SCs), seminiferous tubules, and Blood Testis Barrier are severely structurally damaged by cadmium, which results in sperm loss. The development and function of Leydig cells are hindered by cadmium, which also induces Leydig cell tumors. The testis's vascular system is severely disturbed by cadmium. Cadmium also perturbs the function of somatic cells and germ cells through epigenetic regulation, giving rise to infertile or sub-fertile males. In addition, we also summarized the other findings related to cadmium-induced oxidative toxicity, apoptotic toxicity, and autophagic toxicity, along with their possible mechanisms in the testicular tissue of different animal species. Consequently, cadmium represents a high-risk factor for male fertility.

Potential protective effect of beta-caryophyllene against cadmium chloride-induced damage to the male reproductive system in mouse

Cadmium is a metal that can affect the male reproductive process, possibly leading to infertility. In contrast, beta-caryophyllene (BC) is a sesquiterpene that has shown antigenotoxic, anticancer, and antioxidant properties. Therefore, the aim of the present study was to determine the protective effect of BC against the deleterious effects of cadmium chloride (CC) on various mouse testicular and sperm parameters. We tested three doses of BC (20, 200, and 400 mg/kg) given before and during exposure to 3 mg/kg CC (six days after a single administration). Our results show significant alleviation of the damage induced by CC after the three doses of BC. Regarding the sperm concentration and morphology, the protection with the high dose was complete, and regarding sperm mobility and viability, the protection was more than 74%. In the comet assay, the highest dose showed a reduction of 92.5% in the damage induced by CC, and regarding the number of micronuclei in the spermatids, the reduction was 83.3%. In the oxidative evaluation, regarding sperm lipoperoxidation, the improvement was complete with the high dose, and in the ABTS^.+ test, the improvement in the response to the BC high dose was 26.3%. Regarding testicular lipoperoxidation and protein oxidation, the protective effects of the high BC dose were 87.6% and 89.9%, respectively. We also found that BC protected against the histological and morphometric alterations induced by CC. Therefore, our study clearly demonstrates the beneficial, chemopreventive effect of BC against the mouse sperm and testicular alterations induced by CC.

Phycobiliproteins extract from Spirulina protects against single-dose cadmium-induced reproductive toxicity in male mice

Cadmium (Cd) is known for its many toxic effects on male population such as hypogonadism and fertility difficulties, which are oftenly associated with oxidative stress. As beneficial food, Spirulina(Sp) has been proved efficient against the heavy metal toxicity. This capacity can be associated with its phycobiliproteins (PBP). In this study, the capability of PBP and Sp to treat Cd-induced oxidative damage on the testes and spermatozoa was considered. CD-1 strain mice were orally treated with either Sp or PBP for 10 days prior to single-dose Cd challenge. Sperm quality determinations and testicle histology analysis were performed. Testosterone on serum was measured using enzyme-linked immunosorbent assay (ELISA). Oxidative damage was determined. Antioxidant enzyme activity was analyzed by measuring the activity of super oxide dismutase (SOD), catalase (Cat), and glutathione peroxidase (GpX). The motility and viability of sperm decrease with Cd and improve with PBP and Sp, as the acrosomal reaction (AR) is diminished by PBPs. Testosterone levels decrease due to Cd, and only Sp maintains elevated levels. Cd increases the production of malondialdehyde in the spermatozoa, but not in testes; this production of malondialdehyde in the spermatozoa decreases in the presence of PBP. ROS only decreases with Cd, FBP, and Sp at high concentrations. Advanced oxidative protein products (AOPP) decrease with Cd and PBPs. Cat and GpX increase their activity with Cd and are altered by FBP. Cd produces vascular alterations testes. Within the seminiferous tubule, it produces areas of necrosis and apoptosis, which improve with PBPs and Sp. PBPs have a strong antioxidant activity as they show protective properties against Cd oxidative-induced toxicity on testes and sperm.

Pathophysiological effects of cadmium(II) on human health-a critical review

Cadmium(II) is an omnipresent environmental toxicant emitted from various industrial sources and by anthropogenic sources such as smoking. Cadmium(II) enters our body through various sources including contaminated food and drinks and from active or passive smoking. It spares no organs in our body and the calamities it invites include primarily nephrotoxicity, osteotoxicity, teratogenicity, endocrine disruption, hepatotoxicity and carcinogenicity above all. It brings about a bolt from the blue in the cellular biochemistry by generating reactive oxygen species (ROS), disrupting the factors involved in the repair of DNA lesions and many other toxic nuisances otherwise by modulating the cell signalling machinery and acting as a potent carcinogen above all. In this review, we have tried to decipher some of the mechanisms played by cadmium(II) in exhibiting its toxic effects on various system of our body.

Metal(loid)s and human semen quality: The LIFE Study

Multiple studies have demonstrated a global population-wide decline in semen quality, with sperm concentrations having fallen 50 % over the past 50 years. Several metal and metalloid ("metal(loid)") compounds are known to have testicular toxicity, raising concerns about their contribution to rising infertility. In the male reproductive tract, metal(loid)s can reduce semen quality and disturb function both directly, by inducing tissue damage, and indirectly, by disrupting hormone production and secretion. This study assessed associations between 15 creatinine-adjusted metal(loid)s and 7 measures of semen quality among 413 reproductive-aged men recruited from 16 U.S. counties between 2005-2009. Multi-metal(loid) multivariable linear regression models estimated associations between semen quality endpoints and urinary concentrations of chromium, cobalt, copper, molybdenum, selenium, zinc, antimony, arsenic, barium, cadmium, lead, thallium, tin, tungsten, and uranium. LASSO regression was employed to select model variables and account for multicollinearity of the metal(loid)s. A positive association was observed between tin and sperm morphology (β = 4.92 p = 0.045). Chromium (β = 1.87, p = 0.003) and copper (β= -1.30, p = 0.028) were positively and negatively associated with total sperm count, respectively. With respect to DNA fragmentation, cadmium (β = 12.73, p = 0.036) was positively associated and chromium was negatively associated (β = -5.08, p = 0.001). In this cohort of U.S. population-based men, there was evidence of both positive and negative associations between specific metal(loid)s and semen quality. Additional research is needed to determine interactions between metal(loid)s within a mixture, consistent with typical human exposure, and identify sperm effects resulting from cumulative metal(loid) exposures.

Tissue Bioaccumulation and Toxicopathological Effects of Cadmium and Its Dietary Amelioration in Poultry-a Review

Cadmium (Cd) has been recognized as one of the most toxic heavy metals, which is continuously discharged into environments through anthropogenic (industrial activities, fertilizer production, and waste disposal) and natural sources with anthropogenic sources contributing greater than the natural sources. Therefore, Cd concentration sometimes increases in feeds, fodders, water bodies, and tissues of livestock including poultry in the vicinity of the industrial areas, which causes metabolic, structural, and functional changes of different organs of all animals. In poultry, bioaccumulation of Cd occurs in several organs mainly in the liver, kidney, lung, and reproductive organs due to its continuous exposure. Intake of Cd reduces growth and egg laying performance and feed conversion efficiency in poultry. Chronic exposure of Cd at low doses can also alter the microscopic structures of tissues, particularly in the liver, kidney, brain, pancreas, intestine, and reproductive organs due to increased content of Cd in these tissues. Continuous Cd exposure causes increased oxidative stress at cellular levels due to over-production of reactive oxygen species, exhausting antioxidant defense mechanisms. This leads to disruption of biologically relevant molecules, particularly nucleic acid, protein and lipid, and subsequently apoptosis, cell damage, and necrotic cell death. The histopatholocal changes in the liver, kidneys, and other organs are adversely reflected in hemogram and serum biochemical and enzyme activities. The present review discusses about Cd bioaccumulation and histopathological alterations in different tissues, pathogenesis of Cd toxicity, blood-biochemical changes, and its different ameliorative measures in poultry.

Random Forests Highlight the Combined Effect of Environmental Heavy Metals Exposure and Genetic Damages for Cardiovascular Diseases

Heavy metals are a dangerous source of pollution due to their toxicity, permanence in the environment and chemical nature. It is well known that long-term exposure to heavy metals is related to several chronic degenerative diseases (cardiovascular diseases, neoplasms, neurodegenerative syndromes, etc.). In this work, we propose a machine learning framework to evaluate the severity of cardiovascular diseases (CVD) from Human scalp hair analysis (HSHA) tests and genetic analysis and identify a small group of these clinical features mostly associated with the CVD risk. Using a private dataset provided by the DD Clinic foundation in Caserta, Italy, we cross-validated the classification performance of a Random Forests model with 90 subjects affected by CVD. The proposed model reached an AUC of 0.78 ± 0.01 on a three class classification problem. The robustness of the predictions was assessed by comparison with different cross-validation schemes and two state-of-the-art classifiers, such as Artificial Neural Network and General Linear Model. Thus, is the first work that studies, through a machine learning approach, the tight link between CVD severity, heavy metal concentrations and SNPs. Then, the selected features appear highly correlated with the CVD phenotype, and they could represent targets for future CVD therapies.

Exposure to multiple metals/metalloids and human semen quality: A cross-sectional study

BACKGROUND

Exposure to metals/metalloids, including essential and nonessential elements, has been associated to male reproductive health in animals. However, findings from human studies are inconsistent.

OBJECTIVES

To investigate the impact of exposure to multiple metals/metalloids at environmental levels on the conventional human semen-quality parameters.

MATERIALS AND METHODS

Men living in rural or industrial areas were recruited by personalized letters. No exclusion criteria were applied. Each man provided one semen sample and one blood sample. We analyzed the semen sample both to determine conventional sperm parameters (concentration, progressive motility and normal forms) and to quantify lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), nickel (Ni), vanadium (V) and selenium (Se) levels. The levels of these metals/metalloids were also quantified in venous blood and spermatozoa samples. Associations between the blood/seminal plasma metal/metalloid levels and semen quality parameters were assessed using confounder adjusted logistic regression models. Correlation and interactions between blood/seminal plasma and semen metal/metalloid levels were investigated using the Spearman's correlation.

RESULTS

We found a positive association of seminal plasma cadmium level with lower Total count (OR = 4.48, 95%CI 0.25-80); whereas lead (OR = 4.51, 95%CI 0.86-23) and cadmium (OR = 3.45, 95%CI 0.77-16) seminal plasma levels had a positive association with progressive sperm motility. Overall, these associations remained suggestive after adjustment, though statistically unstable risks. Finally, we found weak interactions between beneficial effects of Se and detrimental ones only for Cd and Pb blood level on sperm concentration, total sperm count and progressive sperm motility.

CONCLUSIONS

Our findings suggest that environmental exposure to Pb and Cd contributes to a decline in human semen quality, whereas Se can have beneficial effects. Measurements of metals/metalloids in the seminal fluid may be more predictable of semen quality than conventional blood measurements.

Trace element analysis of human seminal plasma: A cautionary tale of preanalytical variation and use of non-traditional matrices in human biomonitoring studies

Ensuring harmonization of (ultra-)trace element measurements in non-traditional matrices is a particular analytical challenge that is highlighted in this work for seminal plasma as part of the developmental core at the Wadsworth Center Human Health Exposure Analysis Resource Targeted Laboratory. Seminal plasma was collected from 39 male partners of women undergoing in vitro fertilization and analyzed by inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) following deproteinization with concentrated HNO₃. Validation was accomplished using: 1) two aqueous NIST SRMs; 2) a seminal plasma QC pool, characterized via standard additions; 3) standard additions on a subset of samples; and 4) sample duplicates. Agreement with NIST certified or reference values were obtained to within ±15% for the SRMs, and agreement between aqueous calibration values and standard additions values agreed to within ±10-20% for all elements. Standard additions of seminal plasma samples revealed varying matrix effects for Cu and Cr that were not found for the pooled samples. Duplicate analyses agreed to within ±10-30% depending on element. A potential source of contamination in colloidal silica used for processing seminal plasma was identified that requires further study. Comparisons with literature indicate lack of consensus for As, Cd, Cr, Mn, Pb, and V content in seminal plasma. Further work is needed to improve harmonization of future studies.

A Flavonoid-Rich Extract from Bergamot Juice, Alone or in Association with Curcumin and Resveratrol, Shows Protective Effects in a Murine Model of Cadmium-Induced Testicular Injury

It is known that cadmium damages testis structure and functionality. We examined the effects of nutraceuticals such as a flavonoid-rich extract of bergamot juice (BJe), alone or in association with curcumin (Cur) and resveratrol (Re), on mice testicular dysfunction caused by cadmium chloride (CdCl₂). Controversial data on the protective effects of Cur and Re are available, while no evidence on the possible role of BJe exists. Adult male C57 BL/6J mice were administered with CdCl₂ and treated with Cur, Re, or BJe alone or in combination for 14 days. Then, testes were removed and processed for molecular, structural, and immunohistochemical analyses. CdCl₂ increased the mRNA of IL-1β, TNF-α, p53, and BAX while reduced that of Bcl-2 and induced tubular lesions and apoptosis of germinal cells. Cur, Re, and BJe at 40 mg/kg significantly improved all of these parameters and events, although BJe at 20 mg/kg showed a lower protective effect. The association of Cur, Re, and BJe at both doses of 50/20/20 and 100/20/40 mg/kg brought each parameter close to those of the control. Our results indicate that the nutraceuticals employed in this study and their associations exert a positive action against Cd-induced testicular injury, suggesting a possible protection of testis functionality in subjects exposed to environmental toxicants.

Postnatal cadmium administration affects the presence and distribution of carbohydrates in the sperm membrane during maturation in the epididymis in adult Wistar rats

Cadmium (Cd) is a heavy metal related to a decrease in sperm parameters. The transit of spermatozoa through the epididymis is necessary to generate changes in the sperm membrane, such as the assembly of various carbohydrates that are added to the spermatazoan's surface to prepare it for successful fertilisation of the oocyte. No studies have yet analysed whether Cd alters the presence and distribution of these carbohydrates. We aimed to evaluate the changes induced by Cd in the distribution pattern of N-acetylglucosamine, sialic acid, mannose and fucose on the sperm membrane in the epididymis (e.g. caput, corpus, cauda) and if it alters the epididymal epithelium. Male Wistar pups were treated with Cd doses (0.125, 0.25 and 0.5mg/kg) on postnatal days 1-49. At postnatal day 90, they were humanely killed, sperm samples were obtained from the epididymis and tissue samples were taken for histological analysis. Cd concentrations in the blood and epididymis increased in proportion to the dose administered and decreased the serum testosterone levels and sperm quality. Histological analysis revealed alterations in the epithelium in all Cd-treated groups. Cd altered the distribution patterns of carbohydrates and fluorescence indices. All these alterations affected the structure and functioning of sperm.

External modulators and redox homeostasis: Scenario in radiation-induced bystander cells

Redox homeostasis is imperative to maintain normal physiologic and metabolic functions. Radiotherapy disturbs this balance and induces genomic instability in diseased cells. However, radiation-induced effects propagate beyond the targeted cells, affecting the adjacent non-targeted cells (bystander effects). The cellular impact of radiation, thus, encompasses both targeted and non-targeted effects. Use of external modulators along with radiation can increase radio-therapeutic efficiency. The modulators' classification as protectors or sensitizers depends on interactions with damaged DNA molecules. Thus, it is necessary to realize the functions of various radio-sensitizers or radio-protectors in both irradiated and bystander cells. This review focuses on some modulators of radiation-induced bystander effects (RIBE) and their action mechanisms. Knowledge about the underlying signaling cross-talk may promote selective sensitization of radiation-targeted cells and protection of bystander cells.

D-ribose-L-cysteine modulates lead acetate-induced hematobiochemical alterations, hormonal imbalance, and ovarian toxicity in adult female Wistar rats

Lead is a common environmental toxicant associated greatly with hematological and hormonal imbalance, biochemical alterations, and reproductive abnormalities. This study was conducted to evaluate the effects of D-ribose-L-cysteine (DRLC) on hematobiochemical and reproductive toxicity associated with lead acetate exposure in adult female Wistar rats. Thirty-two adult female Wistar rats (165 ± 20 g) were divided into four groups (n = 8). Group A received normal saline as placebo; Group B received 100 mg/kg BW of lead acetate only; Group C received 100 mg/kg BW of lead acetate and 10 mg/kg BW DRLC (low dose); Group D received 100 mg/kg BW of lead acetate and 30 mg/kg BW of DRLC (high dose). All administration was done via oral gavage for 42 days, thereafter animals were sacrificed; serum was obtained from the blood collected for analysis, ovaries, and uterus was harvested for analysis. The lead acetate only group showed a significant difference in hematological indices relative to control. Additionally, there was a significant decrease in body weight, sodium dismutase, catalase, reduced glutathione, progesterone with a corresponding increase in ovarian weight, MDA, FSH, and LH among the lead acetate only group relative to the control. Histological observation showed atretic antral follicles, with detached granulosa cells, pyknotic nuclei in the granulosa wall in the ovaries of the lead-exposed only group compared to the control. Co-administration of DRLC and lead attenuate the toxicity of lead exposure by restoring the hematological values, biochemical parameters, hormone profile, and morphology of the ovary. Exposure to lead acetate causes deleterious toxicity to hematological and reproductive functions which were ameliorated DRLC supplementation through its antioxidant mechanisms.

The effect of seminal plasma cadmium and lead levels on semen parameters in male subjects of infertile couples: a prospective cohort study

The aim of this prospective study was to investigate whether there is a relationship between seminal plasma cadmium (Cd) and lead (Pb) levels and semen parameters in male partners of infertile couples. Two hundred fifty one (251) men recruited with no history of occupational exposure to toxic metals. After semen analysis, seminal Cd and Pb levels were measured using atomic absorption spectrometry. Cadmium levels in men with hypospermia was significantly higher than men with normal semen volume (p = .049). In contrast, there was no statistically significant difference in median seminal Pb levels between men with hypospermia and men with normal semen volume (p = .13). There was no statistically significant association between seminal plasma Cd and Pb levels sperm concentration, motility, morphology and total progressively motile sperm count. These findings suggest that environmental Cd exposure may contribute to low semen volume in male partners of infertile couples.IMPACT STATEMENTWhat is already known on this subject? Toxic metals may adversely affect both male and female reproductive system.What the results of this study add? Seminal plasma cadmium levels in men with hypospermia were statistically significantly higher than men with normal semen volume.What the implications are of these findings for clinical practice and/or further research? Patients should be informed about possible adverse effects of toxic metals.

Ultrasonic Cutting of Frozen Semen Straws to Optimize the Use of Spermatozoa for In Vitro Fertilization

The objective of the present study was to establish conditions for using technology that can potentially enhance the efficiency of bovine embryos derived from in vitro fertilization (IVF) with frozen semen. Frozen semen from selected bulls can be stored indefinitely in liquid nitrogen as genetic resources; however, these resources are considered consumable because they cannot be regenerated. Therefore, to optimize the utilization of frozen semen, as many oocytes as possible should be fertilized with one straw. However, a sufficient number of prepared oocytes might not be available for one experiment, which can limit the use of the total spermatozoa population. Thus, an economical method for producing embryos needs to be established by optimizing technology for transplantable embryos. In this study, the utilization of frozen semen was increased by dividing the straw with an ultrasonic cutter. The post-thaw survival rate of uncut straws from Korean Proven Bulls did not differ from that of half cuttings. When ultrasonic cutting was applied to frozen semen, spermatozoa could be prepared for IVF trials at least four times, and blastocysts were produced. Therefore, cutting frozen semen with an ultrasonic cutter represents a potentially useful tool to expand genetic resources from excellent breeding stocks. This approach could also be valuable in the field of IVF of endangered species or rare breeds for their preservation, as well as in ovum pick-up (OPU) techniques.

Effects of the methanol root extract of Carpolobia lutea on sperm indices, acrosome reaction, and sperm DNA integrity in cadmium-induced reproductive toxicity in male Wistar rats

OBJECTIVE

Oxidative stress is a mechanism of cadmium-induced reproductive dysfunction. Carpolobia lutea is a free radical scavenger. Our study investigated the potential protective effects of Carpolobia lutea root methanol extract against cadmium-induced reproductive toxicity.

METHODS

We obtained the Carpolobia lutea root in Akure, and it was authenticated at the Forestry Research Institute of Nigeria (FRIN) herbarium, Ibadan, Nigeria, with FHI number 109784. We used Soxhlet extraction to obtain its methanol extract. We used thirty male Wistar rats (150-170g) in this study, (n=5 per group), and treated them as follows: Control (1 ml/kg normal saline), Cd (2 mg/kg), Cd+MCL (2 mg/kg+100 mg/kg), Cd+MCL (2 mg/kg+200 mg/kg), MCL (100 mg/kg), MCL (200 mg/kg). We administered Carpolobia lutea orally for 8 weeks. We administered a single dose of 2 mg/kg of cadmium intraperitoneally. We assessed the sperm profile using a computer-aided sperm analyzer. Under microscopy, we determined the sperm acrosome reaction and the DNA damage. We measured the seminal fructose level using spectrophotometry, and the data were analyzed using ANOVA at p<0.05.

RESULTS

Cd+MCL (2mg/kg+200 mg/kg) significantly increased sperm count (339.0±25.0 vs. 29.0±4.5 million/mL), motility (80.0±0.2 vs. 55.0±4.9%), viability (68.7±2.7 vs. 31.3±2.9%) and decreased abnormal sperm (28.3±1.7 vs. 43.3±2.5%), relative to the cadmium group. Cd+MCL (2mg/kg+200 mg/kg) significantly increased acrosome reaction (68.0±7.5 vs. 15.2±2.4%) and seminal fructose level (0.49±0.06 vs. 0.28±0.06 mmol/L) relative to the cadmium group. Cd+MCL (2mg/kg+200 mg/kg) significantly decreased sperm DNA damage (14.1±1.6 vs. 35.9±5.3%) in relation to the cadmium group.

CONCLUSIONS

Carpolobia lutea root extract improves the sperm variables of rats exposed to cadmium.

Interaction effect of polycyclic aromatic hydrocarbon metabolites and cadmium on semen quality in nonsmokers

Both cadmium (Cd) and polycyclic aromatic hydrocarbons (PAHs) are known reproductive toxicants, but their co-exposure and interaction effect on semen quality particularly in nonsmokers remain unknown. We included 333 nonsmoking men and analyzed their urine and semen samples for heavy metals and PAH metabolites. Restricted cubic spline models were used to explore the dose-response relationship between each OH-PAHs, Cd, and semen quality parameters; the generalized linear model was performed to examine the interaction of each urinary OH-PAH metabolite and Cd concentration on semen quality. Also, stratified analysis was applied to further illustrate the independent effect of PAHs on semen quality parameters in low and high concentration Cd subgroups. The dose-response and interaction effect of PAHs and Cd on male semen quality was observed. Stratified analysis in the high concentration Cd subgroup showed a negative association of 1-OHPyr concentration with semen motility. Our findings indicate that Cd not only modifies the association between PAHs and semen quality but can also exacerbate the toxic effect of pyrene on semen quality parameters. However, further studies with larger samples are needed to confirm the findings.

Pathophysiology and treatment options of varicocele: An overview

Varicocele is the most common correctable cause for male infertility, but not all men with varicocele are affected equally by this condition. The pathophysiology of varicocele-induced fertility remains ill-defined. While evidence suggests that oxidative stress remains a central factor, other mechanisms likely include scrotal hyperthermia, reflux of metabolites, hypoxia and cadmium accumulation. Microsurgical varicocelectomy remains the gold standard treatment option for infertile men with a clinically palpable varicocele and abnormal semen parameters. Newer evidence suggests a potential role for antioxidant supplementation and a meaningful role of varicocelectomy for patients destined for ART to improve pregnancy outcomes.

Cadmium toxicity: effects on human reproduction and fertility

Background Cadmium (Cd) is a non-essential toxic heavy metal, an environmental toxicant, and toxic at a low concentration, and it has no known beneficial role in the human body. Its exposure induces various health impairments including hostile reproductive health. Objective The present review discusses the information on exposure to Cd and human reproductive health impairments including pregnancy or its outcome with respect to environmental and occupational exposure. Methods The present review provides current information on the reproductive toxic potential of Cd in humans. The data were collected using various websites and consulting books, reports, etc. We have included recent data which were published from 2000 onward in this review. Results Cd exposure affects human male reproductive organs/system and deteriorates spermatogenesis, semen quality especially sperm motility and hormonal synthesis/release. Based on experimental and human studies, it also impairs female reproduction and reproductive hormonal balance and affects menstrual cycles. Based on the literature, it might be concluded that exposure to Cd at low doses has adverse effects on both human male and female reproduction and affects pregnancy or its outcome. Further, maternal prenatal Cd exposure might have a differential effect on male and female offspring especially affecting more female offspring. Hence, efforts must be made to prevent exposure to Cd. Conclusion Cd affects both male and female reproduction, impairs hormone synthesis/regulation and deteriorates pregnancy rate or its outcome even at lower doses.

Cadmium exposure enhances organic cation transporter 2 trafficking to the kidney membrane and exacerbates cisplatin nephrotoxicity

Renal accumulation and exposure of cadmium originating from pollution in agricultural land and the prevalence of cigarette smoking remains an unneglectable human health concern. Whereas cadmium exposure has been correlated with increased incidence of a variety of kidney diseases, little is known pertaining to its effect on renal drug disposition and response in patients. Here, we report that cadmium exposure significantly increased the activity of organic cation transporter 2 (OCT2), a critical renal drug transporter recommended in United States Federal Drug Administration guidance for assessment during drug development. Cadmium enhanced OCT2 trafficking to the cell membrane both in vitro and in vivo. Mechanistically cadmium-mediated OCT2 translocation was found to involve protein-protein interaction between serine/threonine-protein kinase AKT2, calcium/calmodulin and the AKT substrate AS160 in in vitro cellular studies. The formed protein complex could selectively facilitate phosphorylation of AKT2 at T309, which induced translocation of OCT2 to the plasma membrane. Moreover, cadmium exposure markedly exacerbated nephrotoxicity induced by cisplatin, an OCT2 substrate, by increasing its accumulation in the mouse kidney. Consistently, there was a significant correlation between plasma cadmium level and alteration of renal function in cervical cancer patients who underwent chemotherapy with cisplatin. Thus, our studies suggest that membrane transporter distribution induced by cadmium exposure is a previously unrecognized factor for the broad variation in renal drug disposition and response.

Logistic Regression Analysis Factors Affecting Sperm Motility and Abnormal Sperm Morphology in Boars

Simple Summary

Reduced sperm motility and morphological abnormalities have significant negative impacts on conception rates in sows and are important indexes of semen. The identification of factors that influence sperm motility and morphology will improve boar fertility in commercial herds. On the basis of analysis of 5042 ejaculates from 385 boars using a logistic regression model, we found that serum Cu excess, serum Fe deficiency, and Pb presence in seminal plasma were risk factors for poor semen quality in boars. More importantly, the presence of seminal plasma Pb had more serious effect on the probability of abnormal sperm morphology than serum Cu excess and serum Fe deficiency. In addition, Yorkshire and Landrace boars had higher sperm motility and lower abnormal sperm morphology than Duroc boars. The difference in serum and seminal plasma elements among boars with different semen qualities may become a guide for regulating these elements used in boar diet. The highly predictive values of serum Cu, Fe, and seminal plasma Pb could be used in the future as an additional tool in semen quality evaluation.

Abstract

Logistic regression models, including variables of boar breed, age, serum, and seminal plasma elements, were used to identify the influencing factors of sperm motility and morphology in this study. Sperm motility degree was classified as grade 0: ≤85% and grade 1: >85%. Abnormal sperm morphology was classified as grade 0: ≤10%, grade 1: 10–20%, and grade 2: >20%. Element concentration of 385 boars was detected by inductively coupled plasma mass spectrometry. Results showed that boars with serum Cu ≥ 2.5 mg/L had lower sperm motility (odds ratio (OR): 0.496; 95% confidence interval (CI): 0.285–0.864) and higher abnormal sperm morphology (OR: 2.003; 95% CI: 1.189–3.376) than those with serum Cu ≤ 2.0 mg/L. Boars with serum Fe ≥ 1.5 mg/L had lower abnormal sperm morphology than those with serum Fe ≤ 1.0 mg/L (OR: 0.463; 95% CI: 0.255–0.842). The presence of Pb in seminal plasma increased abnormal sperm morphology. The probability of abnormal sperm morphology >20% from boars with seminal plasma Pb increased with a range of 5.78–15.30% than that from boars without seminal plasma Pb among three breeds. In conclusion, serum Cu excess, serum Fe deficiency, and seminal plasma Pb are risk factors for poor semen quality in boars.

Cadmium-calcium interference in the Rhinella arenarum oviduct

Given that the cadmium (Cd) toxicity could be due to its interference with the calcium (Ca) homeostasis, the aim of this work was to study the effect of Cd over the presence, distribution and volume density (Vv) of Ca and Ca-ATPase in the secretory cells of the pars preconvoluta (PPC) and the pars convoluta (pc) in Rhinella arenarum. The severe effect of the xenobiotic (CdCl₂ 2.5 mg/kg) in sexually matured females was evaluated. Co-localization, as well as a marked reduction of Ca and Ca-ATPase, was observed in treated animals, in the areas analyzed, compared to control. Low calcium deposits were found in the secreting granules (SG) of the epithelial (ESC) and glandular secretory cells (GSC), while an increase in their cytoplasm and intracellular space was observed. The Ca-ATPase in treated and control animals was detected at the SG and the plasmatic membrane of the ESC and GSC. In relation to the Vv estimates, a substantial reduction of Ca deposits and Ca-ATPase activity was observed in the treated group, with respect to the control. Both amounts of Vv of Ca and Ca-ATPase activity were higher in PPC than in pc, and, higher in ESC than in GSC. These results were associated with the Cd concentration in the oviductal PC, determining that it is a bioaccumulator organ. Thus, this work demonstrated that the Cd interacted with Ca-ATPase, leading to an increase of cytosolic Ca, which is responsible for the possible disruptions in cellular metabolism.

Testicular toxicity of gentamicin in adult rats: Ameliorative effect of lycopene

The current study was aimed to investigate the ameliorative effect of lycopene against gentamicin-induced testicular toxicity in adult rat testes. Pretreatment with lycopene (4 mg/kg/day) significantly prevented the decrease in the absolute testes weight and relative testes weight and the reduction in sperm count, motility, viability, and daily sperm production in gentamicin (100 mg/kg/day)-treated rats. Gentamicin significantly decreased the level of serum testosterone and testicular lactate dehydrogenase-X and G6PDH activities but a marked increase was observed upon pretreatment with lycopene. Testicular caspase-3 and -9 activities were significantly increased but lycopene showed significant protection from gentamicin-induced apoptosis. Oxidative stress was induced by gentamicin treatment as evidenced by increased hydrogen peroxide level and lipid peroxidation and decreased the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and glutathione content. These alterations were effectively prevented by lycopene pretreatment. Histopathological examination showed loss of spermatogenesis and morphological abnormalities of the testis after treatment with gentamycin. These abnormalities were effectively normalized by pretreatment with lycopene. In conclusion, gentamicin decreases rat testes weight and inhibits spermatogenesis. It induces oxidative stress and apoptosis by possible mitochondrial dysfunction. These data provide insight into the mode of action of gentamicin-induced testicular toxicity and the beneficial role provided by lycopene to restore the suppressed spermatogenesis.

Oxidation reduction potential: a new biomarker of male infertility

Oxidative stress is considered a major etiology for male infertility, more specifically idiopathic infertility. The causes of seminal oxidative stress can be intrinsic, such as varicocele or due to the presence of active leukocytes and immature germ cells. Reported external causes are smoking, alcohol or exposure to environmental toxins. Traditional methods to determine the seminal oxidative stress do not evaluate this status directly, but rather measure its components or intermediate products indirectly, instead. The major disadvantages of the traditional methods are related with time and cost as these methods are extremely time consuming and require expensive equipment, consumables and highly skilled laboratory personnel. To overcome these drawbacks, the MiOXSYS® system, a method which directly measures the oxidation-reduction potential (ORP), was developed. The evaluation of the ORP using MiOXSYS® is cost-effective, easy and quick. However, this newly introduced method to evaluate the oxidative status of semen still requires validation in different andrology laboratory settings across the world.

Water and soil pollution as determinant of water and food quality/contamination and its impact on male fertility

Over the past two decades, public health has focused on the identification of environmental chemical factors that are able to adversely affect hormonal function, known as endocrine disruptors (EDs). EDs mimic naturally occurring hormones like estrogens and androgens which can in turn interfere with the endocrine system. As a consequence, EDs affect human reproduction as well as post and pre-natal development. In fact, infants can be affected already at prenatal level due to maternal exposure to EDs. In particular, great attention has been given to those chemicals, or their metabolites, that have estrogenic properties or antagonistic effects on the activity of androgen or even inhibiting their production. These compounds have therefore the potential of interfering with important physiological processes, such as masculinization, morphological development of the urogenital system and secondary sexual traits. Animal and in vitro studies have supported the conclusion that endocrine-disrupting chemicals affect the hormone-dependent pathways responsible for male gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, epidemiological studies have reported an overall decline of male fertility and an increased incidence of diseases or congenital malformations of the male reproductive system. The majority of studies point towards an association between exposure to EDs and male and/or female reproductive system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants has yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Despite the lack of consistency in the results of so many studies investigating endocrine-disrupting properties of many different classes of chemicals, the overall conclusion points toward a positive association between exposure to EDs and reproductive system. Future studies should focus on a uniform systems to examine human populations with regard to the exposure to specific EDs and the direct effect on the reproductive system.

Exposure to Pb and Cd alters MCT4/CD147 expression and MCT4/CD147-dependent lactate transport in mice Sertoli cells cultured in vitro

Sertoli cells (SCs) provide lactate as an energy substrate to develop germ cells during spermatogenesis. Lead (Pb) and cadmium (Cd) can induce SC toxicity. However, the mechanisms remain unclear. This study aimed to investigate the molecular mechanisms by which Pb and Cd alter lactate transport and production by SCs. Mouse SC line (15P-1 cells) were cultured in the absence and presence of lead acetate (PbAc, 1, 10, 20 and 30 μM) or cadmium chloride (CdCl₂, 0.5, 5, 10 and 15 μM) for 24 h. The results showed that PbAc exposure significantly decreased lactate dehydrogenase (LDH) activity and mRNA level, intracellular and extracellular lactate, and MCT4 and CD147 protein levels but increased MCT4 and CD147 mRNA levels. However, PbAc did not alter the glucose uptake, glucose transporters 1 (GLUT1) and 3 (GLUT3) mRNA expression of SCs. Thus, PbAc mainly decreased lactate production by inhibiting LDH activity. In CdCl₂-treated SCs, intracellular lactate content increased but extracellular lactate content decreased significantly, P < .05. The glucose uptake, LDH activity, and mRNA expression of GLUT1, GLUT3 and LDH, all significantly increased. But the mRNA and protein levels of MCT4 and CD147 significantly decreased. Moreover, the fluorescence intensity of co-localizations of the MCT4-CD147 complex dose-dependently decreased in the cell membrane. Thus, CdCl₂ may reduce lactate export by suppressing MCT4 and CD147 expression. These results suggest that PbAc and CdCl₂ disrupt lactate production and transport in mouse SCs by disturbing glycolysis or inhibiting MCT4-CD147 transporter expression and co-localizations.

Treating varicocele in 2018: current knowledge and treatment options

PURPOSE

Varicocele is defined as a state of varicosity and tortuosity of the pampiniform plexus around the testis caused by retrograde blood flow through the internal spermatic vein. The prevalence of clinically relevant varicocele ranges from 5 to 20% in the male population and is often associated with infertility and reduction of sperm quality. In this review, the pathophysiology and clinical aspects of varicocele are reviewed along with therapeutic options and treatment effects on sperm parameters and fertility both in adult and in pediatric/adolescent subjects.

METHODS

We conducted a Medline and a PubMed search from 1965 to 2018 to identify publications related to varicocele clinical aspects, treatment procedures and treatment outcomes. Keywords used for the search were: "varicocele", "varicocelectomy", "sclerotherapy", "male infertility", "subfertility", and "semen abnormalities".

RESULTS

Data from a large number of studies in adolescent and adult males indicate that varicocele correction improves semen parameters in the majority of patients, reducing oxidative stress and improving sperm nuclear DNA integrity either with surgical or percutaneous approach.

CONCLUSIONS

Varicocele repair seems to represent a cost-effective therapeutic option for all males (both adolescent and adults) with a clinical varicocele in the presence of testicular hypotrophy, worsening sperm alterations or infertility. On the other hand, some investigators questioned the role of varicocelectomy in the era of assisted reproduction. Thus, a better understanding of the pathophysiology of varicocele-associated male subfertility is of paramount importance to elucidating the deleterious effects of varicocele on spermatogenesis and possibly formulating new treatment strategies.

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility.

Cadmium Testicular Toxicity in Male Wistar Rats: Protective Roles of Zinc and Magnesium

Cadmium (Cd) is a highly toxic element, which may cause toxicity to most organs in the body. Zinc (Zn) and magnesium (Mg) are essential minerals with probable benefits on Cd harmful effects. Finding an efficient and non-pathological treatment against Cd toxicity seems promising. Fifty adult rats were divided into ten experimental groups of five rats each. The Cd group was treated with 1 mg Cd/kg and the control group received 0.5 cm³ normal saline. The other eight groups received Zn (0.5 and 1.5 mg/kg) and Mg (0.5 and 1.5 mg/kg) either alone or in combination with 1 mg Cd/kg through IP injection for 3 weeks. Testis malondialdehyde (MDA), sperm parameters, and testis histopathology were investigated. Cd reduced sperm parameters and increased testis MDA. Moreover, Cd exposure caused a significant histological damage in testis of male rats. However, Zn or Mg treatment prevented and reversed Cd toxic alterations in testis. These findings suggest that co-administration of Zn or Mg could improve cadmium testicular toxicity in male Wistar rats.

Associations of semen quality with non-essential heavy metals in blood and seminal fluid: data from the Environment and Male Infertility (EMI) study in Lebanon

BACKGROUND

Human exposure to environmental pollutants is widespread. It was suggested that exposure to non-essential heavy metals may adversely affect semen development in men.

PURPOSE

To evaluate associations between non-essential heavy metals in blood and seminal fluid and semen quality parameters in men.

METHODS

Male partners of heterosexual couples were included. The following elements were measured in blood and seminal fluid: lead (Pb), cadmium (Cd), arsenic (As), barium (Ba), mercury (Hg), and uranium (U) using ion-coupled plasma-mass spectrometry.

SETTING

The fertility clinic at the American University of Beirut Medical Center.

MAIN OUTCOME MEASURES

Semen quality parameters (volume, concentration, total count, progressive motility, viability, and normal morphology).

RESULTS

We found that participants with low-quality semen had significantly higher Cd and Ba concentrations in the seminal fluid than participants with normal-quality semen. We also observed significant associations between low sperm viability and higher blood Cd and Ba, as well as higher seminal Pb, Cd, Ba, and U. Furthermore, U concentrations in the seminal fluid were associated with increased odds ratios for below-reference progressive sperm motility and normal morphology.

CONCLUSIONS

Environmental exposures to Pb, Cd, Ba, and U appear to adversely influence sperm development in men. In non-occupationally exposed men, measurements of heavy metals in the seminal fluid may be more predictive of below-reference sperm quality parameters than in blood.

Mimosa pudica Protects the Testes Against Cadmium-Induced Inflammation and Oligospermia: Potential Benefits in Treatment of Heavy Metal Toxicity

Cadmium is a known environmental and industrial pollutant with an enormous tissue disrupting potential. Mimosa pudica (M. pudica) is a creeping annual or perennial herb known to possess anti asthmatic, anti-epileptic, anti-tumour, anti-fertility, aphrodisiac, analgesic, anti-depressant, sedative, emetic properties and a strong radical scavenging activity. This research was aimed at investigating the ameliorative effects of M. pudica on cadmium-induced testicular damage in adult male Sprague Dawley rats. Twenty adult Sprague Dawley rats were employed in the study. They were divided into 4 groups (A-D) of 5 rats each, and toxicity was induced by administering 0.4 mg/ml cadmium chloride through drinking water to groups B-D for 21days. M. pudica extract was administered orally at 250 and 500 mg/kg to groups C and D. Animals in Groups C and D showed remarkable histological improvements in testicular tissue and markedly reduced damages when compared with group B.The active sperm motility of group B (6.00 ± 1.00%) was significantly (p = 0.0001) decreased compared to that of the groups A (15.00 ± 0.00%)) and C (13.00 ± 1.22%). Sperm count analysis of group B (1.36 ± 0.28 × 10⁶/cc), C (4.18 ± 0.81 × 10⁶/cc) and D (2.54 ± 1.13 × 10⁶/cc) were significantly lower (p = <0.05) when compared with group A (12.78 ± 0.92 × 10⁶/cc), respectively. Sperm morphology of group A (70.00 ± 3.16%), B (66.00 ± 2.50), C (74.00 ± 2.45%) and D (64.00 ± 2.45%) recorded no significant difference. This study demonstrates that M. pudica has potential protective and restorative properties on the histoarchitecture of the testes of cadmium-treated rats.