The effect of environmental contaminants on testicular function

The acute effect of respiratory muscle training on cortisol, testosterone, and testosterone-to-cortisol ratio in well-trained triathletes - exploratory study

The study investigated acute changes in cortisol (C) and testosterone (T) associated with a popular RMT method, voluntary isocapnic hyperpnoea (VIH), in well-trained triathletes. 19 athletes (7 females, 12 males) performed a VIH training session with pre- and post- serum C and T measurements. Repeated measures ANOVA was employed to analyze hormone changes during VIH, with additional time-sex interaction. Pearson correlation coefficient has been computed to identify the relationship between hormonal changes and age, anthropometric indices, respiratory muscle strength, and training experience. There was a statistically significant effect for C changes (F = 13.101, p = 0.002, ηp2 = 0.421, ω2 = 0.08). The C concentration was significantly lower after VIH (Mean Difference = -32.49 ± 39.13 nmol*L-1). No significant effects for T, T/C ratio, and time-sex interactions were observed (p > 0.05). Amongst many, significant correlations between the percentage of body fat and changes in C (r=-0.464, p=0.045), body mass and changes in T (r=0.516, p=0.024), height and changes in T (r=0.509, p=0.026) were found. VIH significantly lowered C concentration. No significant effects for T, T/C ratio, and no between-sex differences were observed. Noteworthy individual variability was observed in all the monitored indices. Significant correlations were found between acute hormone changes associated with VIH and selected anthropometric indices. The study provides initial insight into VIH's role in athletes' hormonal balance to possibly guide exercise prescription, autoregulation, arousal state management, and recovery practices in athletes.

The interplay of transition metals in ferroptosis and pyroptosis

Cell death is one of the most important mechanisms of maintaining homeostasis in our body. Ferroptosis and pyroptosis are forms of necrosis-like cell death. These cell death modalities play key roles in the pathophysiology of cancer, cardiovascular, neurological diseases, and other pathologies. Transition metals are abundant group of elements in all living organisms. This paper presents a summary of ferroptosis and pyroptosis pathways and their connection to significant transition metals, namely zinc (Zn), copper (Cu), molybdenum (Mo), lead (Pb), cobalt (Co), iron (Fe), cadmium (Cd), nickel (Ni), mercury (Hg), uranium (U), platinum (Pt), and one crucial element, selenium (Se). Authors aim to summarize the up-to-date knowledge of this topic.In this review, there are categorized and highlighted the most common patterns in the alterations of ferroptosis and pyroptosis by transition metals. Special attention is given to zinc since collected data support its dual nature of action in both ferroptosis and pyroptosis. All findings are presented together with a brief description of major biochemical pathways involving mentioned metals and are visualized in attached comprehensive figures.This work concludes that the majority of disruptions in the studied metals' homeostasis impacts cell fate, influencing both death and survival of cells in the complex system of altered pathways. Therefore, this summary opens up the space for further research.

Effects of microbiota-testis interactions on the reproductive health of male ruminants: A review

Ruminants are one of the world's economically important species, and their reproductive health is critical to the economic development of the livestock industry. In recent years, research on the relationship between microbiota and reproductive health has received much attention. Microbiota disruption affects the developmental health of the testes and epididymis, the male reproductive organs of the host, which in turn is related to sperm quality. Maintaining a stable microbiota protects the host from pathogens and increases breeding performance, which in turn promotes the economic development of animal husbandry. In addition, the effects and mechanisms of microbiota on reproduction were further explored. These findings support new approaches to improving and managing reproductive health in ruminants through the microbiota and facilitate further systematic exploration of microbiota-mediated reproductive impacts.

Effect of quercetin and mirtazapine on spermatogenesis and testis structure in phenylhydrazine-induced hemolytic anemia mice: An experimental study

Anemia poses a significant healthcare challenge across different socioeconomic groups and can result in reproductive system damage through the generation of free radicals and lipid peroxidation. This study examines the protective effects of quercetin (QUE) and mirtazapine (MIR) against the reproductive damage caused by phenylhydrazine (PHZ) in mice. Fifty NMRI mice, aged 8-10 weeks with an average weight of 27.0 ± 2.0 g, were randomly divided into five groups. The control group (Group 1) received oral administration of 10 mL/kg/day of normal saline. Group 2 (PHZ group) received an initial intraperitoneal dose of 8 mg/100 g body weight of PHZ, followed by subsequent doses of 6 mg/100 g every 48 h. Group 3 received PHZ along with oral QUE at a dosage of 50 mg/kg/day. Group 4 received PHZ along with oral MIR at a dosage of 30 mg/kg/day. Group 5 received PHZ along with oral QUE at a dosage of 50 mg/kg/day and MIR at a dosage of 30 mg/kg/day. The treatment duration was 35 days. Sperm samples were collected from the caudal region of the epididymis post-euthanasia to assess the total mean sperm count, sperm viability, motility, DNA damage, and morphology. Testicular tissue was employed to quantify total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) concentrations, while serum levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were analyzed. Additionally, various aspects, including testicular histopathology, oxidative enzyme levels, gene expression related to apoptosis and antiapoptotic pathways, and in vivo fertility index, were evaluated after 35 days. The QUE, MIR, and QUE + MIR groups showed less abnormal morphology and DNA damage, as well as better total and progressive sperm motility, motility characteristics, viability, and plasma membrane function compared to the PHZ group. QUE, MIR, and QUE + MIR administration increased TAC, SOD, and GPx activities in testicular tissue, while reducing MDA levels compared to the PHZ group. Furthermore, QUE, MIR, and QUE + MIR significantly reduced Bax, and caspase-3 expression levels, and increased Bcl-2 expression levels, compared to the PHZ group. Mice treated with QUE, MIR, and QUE + MIR exhibited an increased in vivo fertility index and plasma sex hormone levels compared to the PHZ group. These results show that QUE, MIR, and QUE + MIR might be able to improve the fertility index, boost the testicular antioxidant defense system, and control the death of germ cells. This could mean that they could be used to treat mice with PHZ-induced testicular damage.

Individualizing Basketball-Specific Interval Training Using Anaerobic Speed Reserve: Effects on Physiological and Hormonal Adaptations

PURPOSE

We compared the adaptive responses to supramaximal high-intensity interval training (HIIT) individualized according to anaerobic speed reserve (ASR), the 30-15 Intermittent Fitness Test (VIFT), and velocity associated with maximum oxygen uptake (MAS) to determine which approach facilitates more identical adaptations across athletes with different profiles.

METHODS

Thirty national-level basketball players (age = 28.4 [5] y; body mass = 88.9 [6.3] kg; height = 190 [4.8] cm) were randomly assigned to 3 training groups performing 2 sets of 4, 6, 8, 6, 8, and 10-minute runs (from first to sixth week, respectively), consisting of 15-second running at Δ%20ASR (MAS + 0.2 × ASR), 95%VIFT, and 120%MAS, with 15 seconds recovery between efforts and a 3-minute relief between sets.

RESULTS

All 3 interval interventions significantly (P < .05) enhanced maximum oxygen uptake (V˙O2max), oxygen pulse (V˙O2/HR), first and second ventilatory threshold (VT1 and VT2), cardiac output (Q˙max), stroke volume, peak and average power output, testosterone levels, and testosterone-to-cortisol ratio following the training period. Different values of interindividual variability (coefficient of variation) for the percentage changes of the measured variables were observed in response to HIITASR, HIITvIFT, and HIITMAS for V˙O2max (8.7%, 18.8%, 34.6%, respectively), V˙O2/HR (9.5%, 15.0%, 28.6%), VT1 (9.6%, 19.6%, 34.6%), VT2 (21.8%, 32.4%, 56.7%), Q˙max (8.2%, 16.9%, 28.8%), stroke volume (7.9%, 15.2%, 23.5%), peak power output (20%, 22%, 37.3%), average power output (21.1%, 21.3%, 32.5%), testosterone (52.9%, 61.6%, 59.9%), and testosterone-to-cortisol ratio (55.1%, 59.5%, 57.8%).

CONCLUSIONS

Supramaximal HIIT performed at Δ%20ASR resulted in more uniform physiological adaptations than HIIT interventions prescribed using VIFT or MAS. Although hormonal changes do not follow this approach, all the approaches induced an anabolic effect.

Influence of dietary supplementation with Lepidium meyenii (Maca) on sperm quality in dogs

Maca is a traditional Andean crop used as a nutraceutical for the fertility-enhancing properties that are linked with antioxidant activity. The aim of this study was to evaluate, for the first time, the potential beneficial effects of oral Maca (Lepidium meyenii or Lepidium peruvianum) supplementation in improving reproductive performance in male dogs. Forty-eight male dogs of different breeds were enrolled in the study, fed the same maintenance diet, and exposed to the same environmental conditions. The subjects were divided into four groups of 12 dogs each: Subfertile treatment group, Subfertile control group, Normofertile treatment group, and Normofertile control group. The dogs in the treatment groups received Lepidium meyenii in their diet in a capsule formulation [75 mg/kg Maca extract 10:1, thickening agent (hydroxypropyl methylcellulose), ground rice], while the control groups received placebo capsule (starch). For each subject included in the study, the spermiogram was analyzed at three time points of the sperm cycle: at day 0 (T0), day 31 (T31), and day 62 (T62). Dietary supplementation with Maca in subfertile subjects resulted in a significant increase in ejaculate volume and total sperm count compared to the control group. This increase was also observed in normofertile subjects in the treatment group. In addition, total and progressive motility as well as sperm morphology were significantly improved in the groups treated with Maca compared to the control groups. The results thus highlight, for the first time, the potential efficacy of supplementation with 75 mg/kg of Maca extract daily in improving semen quality in dogs.

The protective effect of aqueous extract of Stevia rebaudiana against tartrazine toxicity in male Wistar rat

Tartrazine is a yellow colouring agent that is commonly used in foods; however, high dosages of Tartrazine affect fertility and create oxidative stress by generating free radicals. A plant species known as Stevia rebaudiana has natural antioxidants that show promise for protecting testicular tissue. Consequently, this study was intended to examine the ameliorative effect of the aqueous extract of S. rebaudiana (Stevia) on the fertility of male Wistar rats induced by the daily oral intake of Tartrazine. Utilizing gas chromatography-mass spectrometry, phytochemical identification was accomplished for Stevia extract. Study groups were separated into several groups: the first group (the control) got distilled water for up to 56 days; the Stevia group (1000 mg/kg), the Tartrazine group (300 mg/kg) and the Stevia and Tartrazine group (the group was given Tartrazine after 1 h of Stevia extract intake). Also, the oxidative damage in testicular tissues was assessed by measuring the levels of malondialdehyde (MDA) and antioxidants (catalase [CAT], superoxide dismutase [SOD] and glutathione reductase [GSH]). Further, histological alterations were examined. In addition, cyclic AMP-responsive element modulator (Crem) gene expression levels and their relative proteins were measured in the testicular tissues using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Sperm analysis and testosterone concentration were also performed. SPSS version 25 was used for the analysis of results while (p < .05) was regarded as significant. Compared with the control group, the results demonstrated that Tartrazine caused a significant reduction (p < .05) in the testosterone hormone level (0.70 ± 0.21) and the Crem protein quantity (1.21 ± 0.23) in the treated Tartrazine group. Also, it had a significant decrease (p < .05) in sperm motility, viability, count and antioxidant levels. Moreover, there was a significant increase (p < .05) in sperm abnormalities, MDA level (7.40 ± 1.10), kidney and liver function parameters, and DNA degradation in the treated Tartrazine group compared with the control group. On the contrary, the Stevia extract intake enhanced the testosterone (2.50 ± 0.60), antioxidants and Crem protein levels (2.33 ± 0.10) with an improvement in sperm quality in the Stevia and Tartrazine-treated group compared with the Tartrazine group. Stevia also caused a significant decrease (p < .05) in the MDA level (3.20 ± 0.20), and sperm abnormalities with an enhancement of the liver and kidney function parameters in the Stevia and Tartrazine-treated group compared to the Tartrazine group. Stevia administration has a protective effect on the testicular tissues and sperm quality against toxicity induced by Tartrazine exposure, so it will be a good antioxidant drug to be administered daily before daily administration of Tartrazine.

Bisphenol-A disturbs hormonal levels and testis mitochondrial activity, reducing male fertility

STUDY QUESTION

How does bisphenol-A (BPA) influence male fertility, and which mechanisms are activated following BPA exposure?

SUMMARY ANSWER

BPA exposure causes hormonal disruption and alters mitochondrial dynamics and activity, ultimately leading to decreased male fertility.

WHAT IS KNOWN ALREADY

As public health concerns following BPA exposure are rising globally, there is a need to understand the exact mechanisms of BPA on various diseases. BPA exposure causes hormonal imbalances and affects male fertility by binding the estrogen receptors (ERs), but the mechanism of how it mediates the hormonal dysregulation is yet to be studied.

STUDY DESIGN SIZE DURATION

This study consisted of a comparative study using mice that were separated into a control group and a group exposed to the lowest observed adverse effect level (LOAEL) (n = 20 mice/group) after a week of acclimatization to the environment. For this study, the LOAEL established by the US Environmental Protection Agency of 50 mg/kg body weight (BW)/day of BPA was used. The control mice were given corn oil orally. Based on the daily variations in BW, both groups were gavaged every day from 6 to 11 weeks (6-week exposure). Before sampling, mice were stabilized for a week. Then, the testes and spermatozoa of each mouse were collected to investigate the effects of BPA on male fertility. IVF was carried out using the cumulus-oocyte complexes from female hybrid B6D2F1/CrljOri mice (n = 3) between the ages of eight and twelve weeks.

PARTICIPANTS/MATERIALS SETTING METHODS

Signaling pathways, apoptosis, and mitochondrial activity/dynamics-related proteins were evaluated by western blotting. ELISA was performed to determine the levels of sex hormones (FSH, LH, and testosterone) in serum. Hematoxylin and eosin staining was used to determine the effects of BPA on histological morphology and stage VII/VIII testicular seminiferous epithelium. Blastocyst formation and cleavage development rate were evaluated using IVF.

MAIN RESULTS AND THE ROLE OF CHANCE

BPA acted by binding to ERs and G protein-coupled receptors and activating the protein kinase A and mitogen-activated protein kinase signaling pathways, leading to aberrant hormone levels and effects on the respiratory chain complex, ATP synthase and protein-related apoptotic pathways in testis mitochondria (P < 0.05). Subsequently, embryo cleavage and blastocyst formation were reduced after the use of affected sperm, and abnormal morphology of seminiferous tubules and stage VII and VIII seminiferous epithelial cells (P < 0.05) was observed. It is noteworthy that histopathological lesions were detected in the testes at the LOAEL dose, even though the mice remained generally healthy and did not exhibit significant changes in BW following BPA exposure. These observations suggest that testicular toxicity is more than a secondary outcome of compromised overall health in the mice due to systemic effects.

LARGE SCALE DATA

Not applicable.

LIMITATIONS REASONS FOR CAUTION

Since the protein expression levels in the testes were validated, in vitro studies in each testicular cell type (Leydig cells, Sertoli cells, and spermatogonial stem cells) would be required to shed further light on the exact mechanism resulting from BPA exposure. Furthermore, the BPA doses employed in this study significantly exceed the typical human exposure levels in real-life scenarios. Consequently, it is imperative to conduct experiments focusing on the effects of BPA concentrations more in line with daily human exposures to comprehensively assess their impact on testicular toxicity and mitochondrial activity.

WIDER IMPLICATIONS OF THE FINDINGS

These findings demonstrate that BPA exposure impacts male fertility by disrupting mitochondrial dynamics and activities in the testes and provides a solid foundation for subsequent investigations into the effects on male reproductive function and fertility following BPA exposure, and the underlying mechanisms responsible for these effects. In addition, these findings suggest that the LOAEL concentration of BPA demonstrates exceptional toxicity, especially when considering its specific impact on the testes and its adverse consequences for male fertility by impairing mitochondrial activity. Therefore, it is plausible to suggest that BPA elicits distinct toxicological responses and mechanistic endpoints based on the particular concentration levels for each target organ.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2018R1A6A1A03025159). No competing interests are declared.

Activation of Nrf-2 Transcription Factor and Caspase Pathway with Royal Jelly Reduces Fluoride Induced Testicular Damage and Infertility in Rats

This study was carried out to investigate the protective properties of royal jelly on the testicular tissue of rats with testicular damage by giving fluoride. Sperm motility, epididymal sperm density and abnormal sperm ratios were examined and visualized with a light microscope. Expression levels of Caspase-3, Bcl-2, Nrf-2, NF-κB, COX-2, TNF-α and IL1-α proteins in testis tissue were determined by western blot technique. As a result of the study, MDA level, expression level of Bcl-2, NFҡB, COX-2, TNF-α and IL1-α proteins, abnormal sperm rates were found higher in Fluoride-50 and Fluoride100 groups compared to other groups. In addition GSH, Catalase enzyme levels, expression levels of Caspase-3 and Nrf-2 proteins were found to be higher in Fluoride + Royal Jelly groups compared to Fluoride-50 and Fluoride-100 groups. In addition, lower degeneration of testicular tissue was found in the histological evaluation in the Fluoride + Royal Jelly groups compared to the other groups. When the data are evaluated royal jelly provides effective protection against testicular damage. From this point of view, we hope that similar results will be obtained when royal jelly is tested on humans.

A Review on the Impact of Oxidative Stress and Medicinal Plants on Leydig Cells

Leydig cells are essential for steroidogenesis and spermatogenesis. An imbalance in the production of reactive oxygen species (ROS) and the cellular antioxidant level brings about oxidative stress. Oxidative stress (OS) results in the dysfunction of Leydig cells, thereby impairing steroidogenesis, spermatogenesis, and ultimately, male infertility. To prevent Leydig cells from oxidative insults, there needs to be a balance between the ROS production and the cellular protective capacity of antioxidants. Evidence indicates that medicinal plants could improve Leydig cell function at specific concentrations under basal or OS conditions. The increased usage of medicinal plants has been considered a possible alternative treatment for male infertility. This review aims to provide an overview of the impact of oxidative stress on Leydig cells as well as the effects of various medicinal plant extracts on TM3 Leydig cells. The medicinal plants of interest include Aspalathus linearis, Camellia sinensis, Moringa oleifera, Morinda officinale, Taraxacum officinale, Trichilia emetica, Terminalia sambesiaca, Peltophorum africanum, Ximenia caffra, Serenoa repens, Zingiber officinale, Eugenia jambolana, and a combination of dandelion and fermented rooibos (CRS-10). According to the findings obtained from studies conducted on the evaluated medicinal plants, it can, therefore, be concluded that the medicinal plants maintain the antioxidant profile of Leydig cells under basal conditions and have protective or restorative effects following exposure to oxidative stress. The available data suggest that the protective role exhibited by the evaluated plants may be attributed to their antioxidant content. Additionally, the use of the optimal dosage or concentration of the extracts in the management of oxidative stress is of the utmost importance, and the measurement of their oxidation reduction potential is recommended.

Punica granatum (Pomegranate) Peel Extract Pre-Treatment Alleviates Fenpropathrin-Induced Testicular Injury via Suppression of Oxidative Stress and Inflammation in Adult Male Rats

Fenpropathrin (FNP) is one of the commonly used insecticides in agriculture and domestically, leading to environmental and health problems. The goal of the current investigation was to determine how well pomegranate peel extract (PGPE) could prevent the testicular toxicity and oxidative stress induced by FNP. Four groups of male Wistar rats were randomly assigned: negative control (corn oil), PGPE (500 mg/kg BW), positive control (FNP; 15 mg/kg BW, 1/15 LD50), and PGPE + FNP. For four weeks, the rats received their doses daily and orally via gavage. The major phytochemical components (total phenolic, flavonoids, and tannins contents) detected in PGPE by GC-MS included ellagic acid, hydroxymethylfurfurole, guanosine, and pyrogallol with high total phenolic, flavonoids, and tannin contents. FNP-treated rats showed a marked elevation in testicular levels of thiobarbituric acid-reactive substances, hydrogen peroxide, and protein carbonyl content, as well as the activity of aminotransferases and phosphatases. Meanwhile. a significant decline in body weight, gonadosomatic index, glutathione, protein contents, enzymatic antioxidants, and hydroxysteroid dehydrogenase (3β HSD, and 17β HSD) activity was observed. In addition, significant alterations in testicular P53, Cas-3, Bcl-2, IL-β, IL-10, testosterone, follicle-stimulating and luteinizing hormones, and sperm quality were detected. Furthermore, biochemical and molecular changes were corroborated testicular histological abnormalities. Moreover, PGPE-pretreated FNP-intoxicated rats demonstrated considerable improvement in the majority of the studied parameters, when compared to FNP-treated groups. Conclusively, PGPE provided a potent protective effect against the testicular toxicity caused by FNP, due to its antioxidant-active components.

A Dynamic In vitro developing testis model reflects structures and functions of testicular development in vivo

To better define appropriate applications of our 3-dimensional testicular co-culture as a model for reproductive toxicology, we evaluated the ability of the model to capture structural and functional elements that can be targeted by reproductive toxicants. Testicular co-cultures were prepared from postnatal day 5 male rats and cultured with a Matrigel overlay. Following a 2-day acclimation period, we characterized functional pathway dynamics by evaluating morphology, protein expression, testosterone concentrations, and global gene expression at a range of timepoints from experimental days 0 to 21. Western blotting confirmed expression of Sertoli cell, Leydig cell, and spermatogonial cell-specific protein markers. Testosterone detected in cell culture media indicates active testosterone production. Quantitative pathway analysis identified Gene Ontology biological processes enriched among genes significantly changing over the course of 21 days. Processes enriched among genes significantly increasing through time include general developmental processes (morphogenesis, tissue remodeling, etc.), steroid regulation, Sertoli cell development, immune response, and stress and apoptosis. Processes enriched among genes significantly decreasing over time include several related to male reproductive development (seminiferous tubule development, male gonad development, Leydig cell differentiation, Sertoli cell differentiation), all of which appear to peak in expression between days 1 and 5 before decreasing at later timepoints. This analysis provides a temporal roadmap for specific biological process of interest for reproductive toxicology in the model and anchors the model to sensitive phases of in vivo development, helping to define the relevance of the model for in vivo processes.

SP22 sperm protein as a potential biomarker of fertility in humans: A preliminary study

Infertility affects approximately 15% of couples of reproductive age, and 50% of the cases are directly related to men. The evaluation of male fertility is based on analyses of routine seminal parameters and the use of more advanced techniques can help identify fertility biomarkers. SP22 sperm protein is considered a biomarker in murine species since its concentration is highly correlated with sperm fertility. As the role of this protein as a biomarker is already well-established in other species, we hypothesized that this same correlation could apply to human. Thus, the present study aimed to investigate possible correlations between SP22 concentration and sperm parameters in fertile and infertile men. For this, a study was carried out on 21 volunteers' seminal samples who were grouped according to fertility as fertile (n = 10) or infertile (n = 11). Conventional and functional sperm analyses, membrane protein extraction, quantification and immunolocalization of SP22 were performed. The infertile volunteers showed an increase in the percentage of sperm with abnormalities in head morphology and a decrease in the percentage of sperm with intact plasma membrane and damaged acrosomal membrane. Serum concentration of the hormone SHBG was also decreased in infertile volunteers. The damage to the plasma membrane was positively correlated with the superoxide anion production. Although none of the functional parameters were correlated with SP22 concentration, type D sperm motility was negatively correlated and type A+B sperm motility was positively correlated. This preliminary study opens new paths in the characterization of SP22 as a non-invasive biomarker for predicting fertility/infertility.

Therapeutic potential of rutin in male infertility: A mini review

Male infertility has become a problem worldwide, and recent research has emphasized the development of more effective therapy options. Among natural compounds, rutin has been widely studied for its potential to treat dysfunction related to male infertility, including a reduction in sperm quality, spermatogenesis disruption and structural disruption in the testis. A thorough review of scientific literature published in several databases, including Google Scholar, PubMed/MEDLINE and Scopus, was used to synthesize the present state of research on the role of rutin in male reproductive health. Rutin has been shown to possess antiapoptotic, antioxidant and anti-inflammatory activities, among others, which are crucial in the management of male infertility. Numerous investigations have shown that rutin protects against male infertility and have explored the underlying mechanisms involved. The present review, therefore, assesses the therapeutic mechanisms involved in male infertility treatment using rutin. Rutin was able to mitigate the induced oxidative stress, apoptosis, inflammation, and related physiological processes that can cause testicular dysfunction. Please cite this article as: Rotimi DE, Elebiyo TC, Ojo OA. Therapeutic potential of rutin in male infertility: a mini review. J Integr Med. 2022; Epub ahead of print.

Adaptive responses of cardiorespiratory system and hormonal parameters to individualized high-intensity interval training using anaerobic power reserve in well-trained rowers

The current study investigated the efficacy of individualizing exercise intensity according to anaerobic power reserve (APR) on hormonal, physiological, and performance adaptations in athletes with different profiles. Sixteen highly-trained male rowers (age = 22 ± 3 years, height = 183 ± 6 cm, weight = 83 ± 7 kg, body fat = 11 ± 2%, experience = 12 ± 5 years) were randomized to a high-intensity interval training consisting of 2 × (6, 6, 8, 8, 10, 10 repetitions from 1st to 6th week, respectively) × 60 s intervals using a rowing ergometer at ∆%30 APR (APR_∆%30) or the same sets and repetitions at 130% maximal aerobic power (MAP_130%). In both groups, relief intervals were set at 1:1 with 3 min of rest between sets. On four occasions separated by 24 h recovery, participants attended the laboratory to assess 2000-m rowing ergometer performance, maximal oxygen uptake (V̇O₂max) and related physiological adaptations, and hormonal parameters. Significant increases were observed in 2000-m performance, V̇O₂max, ventilation at V̇O₂max, first and second ventilatory threshold, MAP and maximal sprinting power (MSP), total testosterone, and testosterone to cortisol ratio in response to 6 weeks of APR_∆%30 and MAP_130% protocols. The coefficient of variation (inter-subject variability) in the adaptive response of cardiorespiratory parameters to HIIT performed using the APR_∆%30 protocol was lower than those of the MAP_130% group. However, this is not the case for hormonal changes. Prescribing HIIT based on an athlete's APR may help to create a more consistent level of the mechanical and physiological stimulus relative to the athlete's capacity, potentially leading to more similar adaptations across athletes with varying profiles. Mechanisms influencing total testosterone are multifactorial and are not affected by this approach.

Mechanisms of Male Reproductive Toxicity of Polybrominated Diphenyl Ethers

Polybrominated diphenyl ethers (PBDE) are a group of flame retardants used in a variety of artificial materials. Despite being phased out in most industrial countries, they remain in the environment and human tissues due to their persistence, lipophilicity, and bioaccumulation. Populational and experimental studies demonstrate the male reproductive toxicity of PBDEs including increased incidence of genital malformations (hypospadias and cryptorchidism), altered weight of testes and other reproductive tissues, altered testes histology and transcriptome, decreased sperm production and sperm quality, altered epigenetic regulation of developmental genes in spermatozoa, and altered secretion of reproductive hormones. A broad range of mechanistic hypotheses of PBDE reproductive toxicity has been suggested. Among these hypotheses, oxidative stress, the disruption of estrogenic signaling, and mitochondria disruption are affected by PBDE concentrations much higher than concentrations found in human tissues, making them unlikely links between exposures and adverse reproductive outcomes in the general population. Robust evidence suggests that at environmentally relevant doses, PBDEs and their metabolites may affect male reproductive health via mechanisms including AR antagonism and the disruption of a complex network of metabolic signaling.

Paternal cadmium exposure affects testosterone synthesis by reducing the testicular cholesterol pool in offspring mice

Cadmium（Cd） is a heavy metal that is harmful to human health. Early studies have shown that cadmium can damage testicular structure, affecting testosterone synthesis and spermatogenesis. However, the effect of paternal Cd exposure on the reproductive system of offspring remains unclear. In this study, male 8-week C57BL/6 J mice were used as research objects, and Cd was injected intraperitoneally every other day at a dose of 1 mg/kg for 5 weeks, after which the effect on the reproductive system of offspring male mice was studied. Our results showed that the body weight of the offspring male mice increased faster, with increases of the testicular and epididymis indices under Cd exposure. At the same time, the serum testosterone and free cholesterol decreased, total cholesterol increased, and the sperm concentration decreased. Further qRT-PCR and western blot analyses showed that the expressions of StAR, P450scc, 3β-HSD and 17β-HSD, which are related to testosterone synthesis, was significantly downregulated. Additionally, ATGL, LDLR and SR-BI, which are related to the intracellular cholesterol pool were downregulated, leading to the reduction of the cholesterol pool and the accumulation of lipid droplets. Oil red O and BODIPY staining revealed an increase in the abundance of lipid droplets in testicular tissue of newborn and adult mice. Prediction of tsRNA target genes in the sperm of parents and testicular transcriptome of newborn mice showed that the differentially expressed genes were associated with catabolism of fatty acids, cholesterol and ion channels, while the mitochondrial and lysosome functions of testicular tissue of adult offspring mice were decreased. Overall, our results suggest that paternal Cd exposure reduced the intracellular cholesterol pool of testicular of offspring, affected testosterone synthesis and reproductive system development.

First study of in vitro protective effect of Lepidium meyenii (Maca) on frozen–thawed bovine spermatozoa

Background and Aim:

Lepidium meyenii Walp (Maca) is an herbaceous plant that grows in the Peruvian Andes and it has been widely used as a nutritional supplement and fertility enhancer and has been used in the treatment of a variety of diseases, such as rheumatism, respiratory disorders, and anemia. The most notable feature of Maca is its potent antioxidant capacity, which helps in the scavenging of free radicals and protection of cells from oxidative stress. This study aimed to evaluate the in vitro effect of Maca extract on thawed sperm cells from bulls.

Materials and Methods:

Three dilutions of 1, 10, and 100 mg/mL of Maca extract were incubated with frozen–thawed bovine semen and analyzed at 1, 3, and 24 h of exposure time, evaluating the activity of the extract on the DNA, motility, morphology, viability, integrity of the membrane and acrosome of spermatozoa.

Results:

The Maca extract improved the studied sperm parameters of motility, acrosome integrity, vitality, and DNA integrity of sperm cells at a concentration of 10 mg/mL, and at 1 mg/mL, an improvement was observed in the morphology and integrity of the membrane. However, the best activity of the Maca extract was observed on the DNA integrity of the sperm, which was effective at the three concentrations evaluated after 24 h of incubation.

Conclusion:

The results indicate that L. meyenii can help in maintaining spermatozoa cellular integrity after the frozen–thaw process, especially in the protection against DNA fragmentation. Therefore, Maca would be a feasible supplementation to protect sperm to maintain their fertile ability after thawing.

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.

Effects of different DDE exposure paradigms on testicular steroid hormone secretion and hepatic oxidative stress in male Long-Evans rats

Chronic exposure to low doses of anthropogenic chemicals in the environment continues to be a major health issue. Due to concerns about the effects in humans and wildlife, use of persistent organic pollutants, such as dichlorodiphenyltrichloroethane (DDT), is prohibited. However, their ubiquitous nature and persistence allows them to remain in the environment at low levels for decades. Dichlorodiphenyldichloroethylene (DDE) is the most persistent metabolite of DDT and has been shown to cause hepatotoxicity, nephrotoxicity, hormonal disorders, and induce oxidative stress in many organisms. Although the effects of acute exposure to DDT and its metabolite DDE have been extensively studied, the chronic effects of sub-lethal DDE exposure at levels comparable to those found in the environment have not been well documented. Long-Evans male rats were used to determine the effect of relatively chronic and short term DDE (doses ranged from 0.001 to 100 μg/L) exposure on endocrine function and oxidative stress at different developmental time points. We found that circulating serum testosterone (T) levels were significantly decreased and T secretion in testicular explants were significantly influenced in a dose dependent manner in both pre-pubertal and pubertal male rats after DDE exposure, with pubertal rats being the most affected contrary to our original prediction. Additionally, exposure to DDE increased expression of protein oxidation indicating a possible increase in cellular damage caused by oxidative stress. This study suggests that chronic exposures to environmentally relevant levels of DDE affected testicular function and decreased T secretion with implications for reproductive capacity.

Differential Expression Profiles and Potential Intergenerational Functions of tRNA-Derived Small RNAs in Mice After Cadmium Exposure

Cadmium (Cd) is a toxic heavy metal and ubiquitous environmental endocrine disruptor. Previous studies on Cd-induced damage to male fertility mainly focus on the structure and function of testis, including cytoskeleton, blood-testis barrier, and steroidogenesis. Nevertheless, to date, no studies have investigated the effects of Cd exposure on sperm epigenetic inheritance and intergenerational inheritance. In our study, we systematically revealed the changes in sperm tRNA-derived small RNAs (tsRNA) profiles and found that 14 tsRNAs (9 up-regulated and 5 down-regulated) were significantly altered after Cd exposure. Bioinformatics of tsRNA-mRNA-pathway interactions revealed that the altered biological functions mainly were related to ion transmembrane transport, lipid metabolism and cell membrane system. In addition, we focused on two stages of early embryo development and selected two organs to study the impact of these changes on cell membrane system, especially mitochondrion and lysosome, two typical membrane-enclosed organelles. Surprisingly, we found that the content of mitochondrion was significantly decreased in 2-cell stage, whereas remarkably increased in the morula stage. The contents of mitochondrion and lysosome were increased in the testes of 6-day-old offspring and livers of adult offspring, whereas remarkably decreased in the testes of adult offspring. This provides a possible basis to further explore the effects of paternal Cd exposure on offspring health.

Bisphenol S exposure induces cytotoxicity in mouse Leydig cells

Bisphenol S (BPS), an increasingly used alternative to bisphenol A, has been linked to testosterone deficiency and male reproductive dysfunction in laboratory animals. This study aimed to examine the cytotoxicity of BPS exposure to Leydig cells and to investigate its possible mechanisms. After treatment with BPS (100, 200 and 400 μM) for 48 h in vitro, TM3 mouse Leydig cells exhibited a dose-dependent decrease in the viability. Furthermore, BPS challenge triggered oxidative stress manifested by compromised activities of superoxide dismutase and catalase with exaggerated formation of reactive oxygen species. Especially, BPS exposure resulted in augmented mitochondrial permeability transition pore opening, dissipated mitochondrial membrane potential and reduced ATP generation, along with an altered energy metabolism. Moreover, BPS stimulation enhanced BAX expression and caspase-3 activity and inhibited BCL-2 expression. In addition, BPS-treated TM3 cells showed an accumulation of autophagic vacuoles, together with increased Beclin1 and P62 expression and elevated LC3B-II/LC3B-I ratio. These results demonstrated that in vitro exposure to BPS exerted cytotoxicity to TM3 Leydig cells through inducing oxidative stress, mitochondrial impairment, autophagic disturbance and apoptosis.

Oxidative Stress and Toxicity in Reproductive Biology and Medicine: A Comprehensive Update on Male Infertility Volume II - Conclusion

Infertility is a globally under-recognized public health problem significantly impacting individual health and socioeconomics affecting millions of couples. The reasons for infertility are manifold and not only include many couples decision to postpone having children but also diseases (e.g., diabetes, infections, or varicocele), lifestyle (e.g., obesity), and environmental factors (e.g., bisphenol A, DTT or dioxin). In the pathology of many causes of infertility, oxidative stress plays a significant role as reactive oxygen species (ROS) exert significant detrimental effects. On the other hand, a small amount of ROS is essential to trigger physiological events such as capacitation. Therefore, a fine balance between oxidation and reduction has to be maintained. Apart from treating the underlying disease or correcting the cause of the infertility, oxidative stress can be treated by antioxidant supplementation. Since plants and their extracts contain numerous phytochemicals which exhibit antioxidant activity, many people tend to use herbal products. Alternatively, isolated antioxidants such as vitamin C or E are also used. However, when using purified antioxidants, it is essential that the redox balance is maintained to avoid a "reductive stress" situation, which is as harmful as oxidative stress.

The Role of Environmental Toxicant-Induced Oxidative Stress in Male Infertility

Infertility is a serious public health issue affecting around 15% of couples globally. Of the 60-80 million people of reproductive age affected by infertility, 40-50% are due to male factor while 30-40% of cases are still idiopathic. The recent global deterioration in sperm quality raises apprehensions regarding the toxic effects of environmental pollutants on reproductive health of males. Environmental toxicants have shown strong evidences for inducing oxidative stress affecting spermatogenesis severely, thereby leading to reduced sperm motility, count, and DNA damage. Reactive oxygen species (ROS) influences the spermatozoa development and transit process both internally and externally. Low level of ROS is indispensable for critical physiological sperm processes like sperm capacitation, motility, acrosome reaction, hyper-activation, sperm-oocyte interaction, etc., while excessive ROS disrupt antioxidant molecules which is detrimental to normal functioning of the sperm. Hence, identification of potential environmental toxicant may have clinical relevance for early screening and diagnosis of male infertility.

Flusilazole-induced damage to SerW3 cells via cytotoxicity, oxidative stress and lipid metabolism: An in vitro study

Flusilazole (C₁₆H₁₅F₂N₃Si) is a triazole fungicide and it is being used widely in recent years to control fungal infections in various fruits and vegetables. This study aims to evaluate the impact of flusilazole on cytotoxicity, ATP-dependent cassette transporter proteins (ABC transporter proteins) in SerW3 cells. In this study, SerW3 cells have administrated with 25, 100, and 200 μM flusilazole, cell viability was performed. The quantity of the cellular lipids was evaluated spectrophotometrically. Moreover, the expression of the ABCA1 and ABCB1 proteins determined by immunofluorescence microscopy. Furtherly, evaluation of the cell death type and measurement of the activity of the antioxidant enzymes was performed. According to the results, flusilazole treatment gave rise to inhibition in cell viability, increase in apoptotic cell number, reduction in cellular lipids, and inhibition in the expression of ABCA1 and ABCB1 proteins. Furthermore, it caused decreases in antioxidant enzyme activities. It may be concluded that flusilazole administration may cause infertility/subfertility. The mechanism of action can be due to cytotoxicity, impairment of the detoxification mechanisms, lipid metabolism, and dysregulation of cell functions.

The Impact of Endocrine-Disrupting Chemicals in Male Fertility: Focus on the Action of Obesogens

The current scenario of male infertility is not yet fully elucidated; however, there is increasing evidence that it is associated with the widespread exposure to endocrine-disrupting chemicals (EDCs), and in particular to obesogens. These compounds interfere with hormones involved in the regulation of metabolism and are associated with weight gain, being also able to change the functioning of the male reproductive axis and, consequently, the testicular physiology and metabolism that are pivotal for spermatogenesis. The disruption of these tightly regulated metabolic pathways leads to adverse reproductive outcomes. The permanent exposure to obesogens has raised serious health concerns. Evidence suggests that obesogens are one of the leading causes of the marked decline of male fertility and key players in shaping the future health outcomes not only for those who are directly exposed but also for upcoming generations. In addition to the changes that lead to inefficient functioning of the male gametes, obesogens induce alterations that are “imprinted” on the genes of the male gametes, establishing a link between generations and contributing to the transmission of defects. Unveiling the molecular mechanisms by which obesogens induce toxicity that may end-up in epigenetic modifications is imperative. This review describes and discusses the suggested molecular targets and potential mechanisms for obesogenic–disrupting chemicals and the subsequent effects on male reproductive health.

Cadmium attenuates testosterone synthesis by promoting ferroptosis and blocking autophagosome-lysosome fusion

Ferroptosis is a newly defined programmed cell death pathway characterized by iron overload and lipid peroxidation. Increasing studies show that autophagy regulates testosterone synthesis and promotes ferroptosis. Testosterone is essential for sexual development and the maintenance of male characteristics. The deficiency of testosterone induced by cadmium (Cd) can severely affect male fertility. However, the underlying mechanism of testosterone reduction after Cd exposure remains blurry. In this study, we found that Cd affected iron homeostasis and elicited ferroptosis, ultimately reducing testosterone production. Mechanically, our findings revealed that Cd-induced ferroptosis depended upon the excessive activation of Heme oxygenase 1 (HMOX1) and the release of free iron from heme. Additionally, Cd exposure promoted autophagosome formation but blocked autophagosome-lysosome fusion, which attenuated the absorption of total cholesterol and triglycerides, further aggravating testosterone synthesis disorder. Collectively, Cd induced ferroptosis by iron homeostasis dysregulation, mediated by excessive activation of HMOX-1. The disruption of autophagy flow contributed to Cd-induced testicular dysfunction and attenuated testosterone synthesis.

Histopathological Findings of Testicular Tissue Following Cadmium Toxicity in Rats

Background & Objective:

Reproductive toxicity of cadmium (Cd) as an environmental toxicant has been proved in animals and humans. Exposure to Cd impairs testes organs and can reduce male fertility. The present study was designed to investigate the spectrum of histopathological changes in testicular tissue focusing on Sertoli cells in rats following Cd intoxication.

Methods:

In the present experiment, acute testicular toxicity was induced by an intraperitoneal injection of 1.2 mg/kg CdCl₂ to the animals in the test group, while the control group received normal saline. After 52 days, the animals were euthanized, and testicular tissue was stained by Hematoxylin and Eosin. In addition, immunohistochemical staining was performed on Sertoli cells for Wilms' Tumor, Melan-A, and CD99 to evaluate histopathological changes.

Results:

Cd caused significant alterations in seminiferous tubules with varying effects on the patterns of spermatozoa production. These histopathological changes were significantly higher in the Cd group, compared to the control group.

Conclusion:

The Cd-induced stepwise spectrum changes included sloughing, disorganization, hypospermatogenesis, spermatic cell arrest, germ cell hypoplasia, Sertoli cell-only pattern, fibro-hyalinized seminiferous tubules, and calcification. Sertoli cells accumulated and created multinucleated giant cells in the seminiferous tubules during the atrophic process, which could be dependent upon Sertoli cells viability and function.

Effect of Copper Sulphate and Cadmium Chloride on Non-Human Primate Sperm Function In Vitro

In order to address the large percentage of unexplained male infertility in humans, more detailed investigations using sperm functional tests are needed to identify possible causes for compromised fertility. Since many environmental and lifestyle factors might be contributing to infertility, future studies aiming to elucidate the effect of such factors on male fertility will need the use of appropriate research models. The current study aimed to assess the effects of two heavy metals, namely copper sulphate, and cadmium chloride, on non-human primate (NHP) sperm function in order to establish the possibility of using these primate species as models for reproductive studies. Our combined results indicated that the functionality of NHP spermatozoa is inhibited by the two heavy metals investigated. After in vitro exposure, detrimental effects, and significant lowered values (p < 0.05) were obtained for sperm motility, viability and vitality, acrosome intactness, and hyperactivation. These metals, at the tested higher concentrations, therefore, have the ability to impair sperm quality thereby affecting sperm fertilizing capability in both humans and NHPs.

An Integrated Analysis of Network Pharmacology, Molecular Docking, and Experiment Validation to Explore the New Candidate Active Component and Mechanism of Cuscutae Semen-Mori Fructus Coupled-Herbs in Treating Oligoasthenozoospermia

PURPOSE

One of the most common types of male infertility is recognized as oligoasthenozoospermia (OA), characterized by low sperm count and quality in males. As a traditional Chinese medicine (TCM), Cuscutae Semen-Mori Fructus coupled-herbs (CSMFCH) has been known to act a curative effect on OA for thousands of years. Nevertheless, the substantial basis and molecular mechanism of CSMFCH in treating OA remain elusive.

METHODS

Herein, an integrated approach, including network pharmacology, molecular docking, and experiment validation, was utilized to reveal the new candidate active component and mechanism of CSMFCH in treating OA.

RESULTS

The results show that kaempferol is the most significant bioactive component of CSMFCH on OA. The mechanism and targets of CSMFCH against OA are relevant to hormone regulation, oxidant stress, and reproductive promotion. In order to validate network pharmacology results, molecular docking and experiment validation were conducted. In detail, molecular docking was employed to verify the strong binding interactions between kaempferol and the core targets. UHPLC-Q-Orbitrap-MS was used to identify kaempferol in the CSMFCH extract. In vitro and in vivo experiments further proved CSMFCH and kaempferol could enhance the mouse Leydig (TM3) and mouse Sertoli (TM4) cell viability, improve the male reproductive organ weights, sperm quality, and decrease testis tissue damage in the OA mouse model induced by CP.

CONCLUSION

Our results not only identify the new candidate active component of CSMFCH in treating OA but also provide new insights into the mechanisms of CSMFCH against OA.

Low Doses of Glyphosate/Roundup Alter Blood-Testis Barrier Integrity in Juvenile Rats

It has been postulated that glyphosate (G) or its commercial formulation Roundup (R) might lead to male fertility impairment. In this study, we investigated the possible effects of G or R treatment of juvenile male rats on blood-testis barrier function and on adult male sperm production. Pups were randomly assigned to the following groups: control group (C), receiving water; G2 and G50 groups, receiving 2 and 50 mg/kg/day G respectively; and R2 and R50 groups receiving 2 and 50 mg/kg/day R respectively. Treatments were performed orally from postnatal day (PND) 14 to 30, period of life that is essential to complete a functional blood-testis barrier. Evaluation was done on PND 31. No differences in body and testis weight were observed between groups. Testis histological analysis showed disorganized seminiferous epithelium, with apparent low cellular adhesion in treated animals. Blood-testis barrier permeability to a biotin tracer was examined. A significant increase in permeable tubules was observed in treated groups. To evaluate possible mechanisms that could explain the effects on blood-testis barrier permeability, intratesticular testosterone levels, androgen receptor expression, thiobarbituric acid reactive substances (TBARS) and the expression of intercellular junction proteins (claudin11, occludin, ZO-1, connexin43, 46, and 50 which are components of the blood-testis barrier) were examined. No modifications in the above-mentioned parameters were detected. To evaluate whether juvenile exposure to G and R could have consequences during adulthood, a set of animals of the R50 group was allowed to grow up until PND 90. Histological analysis showed that control and R50 groups had normal cellular associations and complete spermatogenesis. Also, blood-testis barrier function was recovered and testicular weight, daily sperm production, and epididymal sperm motility and morphology did not seem to be modified by juvenile treatment. In conclusion, the results presented herein show that continuous exposure to low doses of G or R alters blood-testis barrier permeability in juvenile rats. However, considering that adult animals treated during the juvenile stage showed no differences in daily sperm production compared with control animals, it is feasible to think that blood-testis barrier impairment is a reversible phenomenon. More studies are needed to determine possible damage in the reproductive function of human juvenile populations exposed to low doses of G or R.

Exogenous Factors Affecting the Functional Integrity of Male Reproduction

Natural processes along with increased industrial production and the irresponsible behavior of mankind have resulted in environmental pollution. Environmental pollutants can be categorized based on their characteristics and appearance into the following groups: physical, biological, and chemical. Every single one of them represents a serious threat to the male reproductive tract despite the different modes of action. Male gonads and gametes are especially vulnerable to the effect of exogenous factors; therefore, they are considered a reliable indicator of environmental pollution. The impact of xenobiotics or radiation leads to an irreversible impairment of fertility displayed by histological changes, modulated androgen production, or compromised spermatozoa (or germ cells) quality. The present article reviews the exogenous threats, male reproductive system, the mode of action, and overall impact on the reproductive health of humans and animals.

Reproductive toxic potential of phthalate compounds - State of art review

Phthalates are pervasive compounds, and due to the ubiquitous usage of phthalates, humans or even children are widely exposed to them. Since phthalates are not chemically bound to the plastic matrix, they can easily leach out to contaminate the peripheral environment. Various animal and human studies have raised vital health concern including developmental and reproductive toxicity of phthalate exposure. The present review is based upon the available literature on phthalates with respect to their reproductive toxic potential. Common reproductive effects such as declined fertility, reduced testis weight, variations in accessory sex organs and several female reproductive disorders appeared to be largely associated with the transitional phthalates. Among the higher molecular weight phthalates (≥ C7), di-isononyl phthalate (DINP) produces some minor effects on development of male reproductive tract and among low molecular weight phthalates (≤C3), di-methyl (DMP) and di-isobutyl (DIBP) phthalate produce some adverse effects on male reproductive system. Whereas transitional phthalates such as di-butyl phthalate, benzyl butyl phthalate, and di-(2-ethylhexyl) phthalate have shown adverse effects on female reproductive system. Owing to these, non-toxic alternatives to phthalates may be developed and use of phthalates could be rationalized as an important issue where human reproduction system is involved. Though, more epidemiological studies are needed to substantiate the reported findings on phthalates.

Decabromodiphenyl ether (BDE-209) exposure to lactating mice perturbs steroidogenesis and spermatogenesis in adult male offspring

Decabromodiphenyl ether (BDE-209) is widely used as a flame retardant in many products like electronic equipments, plastics, furniture and textiles. BDE-209, a thyroid hormones (THs)-disrupting chemical, affects male reproductive health through altered THs status in mouse model. The present study was designed in continuation to our earlier work to elucidate whether early life exposure to BDE-209 has a long term potential risk to male reproductive health. This study, therefore, aimed to evaluate the effect of maternal BDE-209 exposure during lactation and to elucidate possible mechanism(s) of its action on male reproduction in adult Parkes mice offspring. Lactating female Parkes mice were orally gavaged with 500, and 700 mg/kg body weight of BDE-209 in corn oil from postnatal day (PND) 1 to PND 28 along with 6-propyl-2-thiouracil (PTU)-treated positive controls and vehicle-treated controls. Male pups of lactating dams were euthanized at PND 75. Maternal BDE-209 exposure during lactation markedly affected histoarchitecture of testis and testosterone production with concomitant down-regulation in the expression of various steroidogenic markers in adult offspring. Maternal exposure to BDE-209 during lactation also interfered with germ cell dynamics and oxidative status in testes of adult mice offspring. A decreased expression of connexin 43 and androgen receptor was also evident in testes of these mice offspring; further, number, motility and viability of spermatozoa were also adversely affected in these mice. The results thus provide evidences that maternal exposure to BDE-209 during lactation causes reproductive toxicity in adult mice offspring.

The effects of CoQ10 supplement on matrix metalloproteinases, oxidative DNA damage and pro-inflammatory cytokines in testicular ischaemia/reperfusion injury in rats

We aimed to study the effect of coenzyme Q10 on pro-inflammatory cytokine, matrix metalloproteinase, oxidative DNA damage, caspase 3 and caspase 8 in ischaemia/reperfusion injury led to by testicular torsion/detorsion. Our research is a controlled experimental animal research using rats. This study was conducted with fifty-six adult male Albino Wistar rats. Interleucine-1β, 2, 6, 10, tumour necrosis factor-α, matrix metalloproteinase-2, 3, 9, 13, tissue inhibitor matrix metalloproteinase-1, 2, malondialdehyde and leucocyte 8-hydroxy-2-deoxy guanosine/10⁶ deoxyguanosine was detected in serum and tissue samples. In addition, immunohistochemical analysis of caspase 2 and caspase 8 was performed. In testicular I/R injury, especially 24 hr after detorsion, oxidative damage pro-inflammatory cytokines and matrix metalloproteinases were increased. At the coenzyme Q10 group, a meaningful decrease was observed in these parameters. In addition, a decrease in the expression of caspase3 and caspase 8 was viewed in coenzyme Q10-treated groups. The coenzyme Q10 has beneficial effects on oxidative damage, pro-inflammatory cytokine levels, remodelling of extracellular matrix and apoptosis in testicular I/R injury.

Bromelain from Ananas comosus stem attenuates oxidative toxicity and testicular dysfunction caused by aluminum in rats

BACKGROUND

Aluminum (Al) has been reported to induce testicular injury via oxidative stress. Ananas comosus stem extract is an inexpensive byproduct waste rich in bromelain which is a group of sulfur-containing enzymes known for its biological activities and medicinal applications. So, the current investigation aims to evaluate the efficacy of bromelain in counteracting oxidative injury and testicular dysfunction stimulated by aluminum in rats.

METHODS

Male adult Wistar rats were divided into four groups. The first group used as control, however, the second and third groups were received bromelain (250 mg/kg) and AlCl₃ (34 mg/Kg, 1/25 LD₅₀), and the fourth group supplemented with bromelain one hour before AlCl₃ intoxication, respectively. Bromelain was administered daily while AlCl₃ was given every other day by oral gavages for one month.

RESULTS

Al intoxicated animals revealed an elevation in lipid peroxidation (TBARS and H₂O₂) level and lactate dehydrogenase (LDH) activity. However, reduced glutathione (GSH) and protein contents, antioxidant enzymes (SOD, CAT, GPx, GR, GST), phosphatases (ALP, AcP) and aminotransferases (AST, ALT) activities were significantly reduced. Additionally, considerable amendments in hormonal levels (testosterone, luteinizing and follicle-stimulating hormone) and sperm characteristics were spotted. Further, histological variations in the testes section were detected and this supports the biochemical observations. Otherwise, rats supplemented with bromelain alone diminished TBARS and H₂O₂ and augmented mostly other parameters. Furthermore, supplementation with bromelain before Al intoxication in rats exhibited worthy betterment in oxidative stress markers, hormones, and sperm quality compared to Al treated group.

CONCLUSION

In conclusion, bromelain had a powerful protective role against Al-induced testicular dysfunction so, it represents a novel approach in metal toxicity processing.

Protective effect of vitamin E on sperm quality and in vitro fertilizing potential and testosterone concentration in polyvinyl chloride treated male rats

Polyvinyl chloride (PVC) has toxic effects through the induction of oxidative stress in the body and testicles. Vitamin E (Vit E) is a dietary compound that functions as an antioxidant scavenging toxic free radicals. The present study aimed to probe the protective effect of Vit E against PVC-induced reprotoxicity in male rats. In this experimental study, 24 male rats were randomly divided into four groups (n=6) including control, Vit E (150 mg kg^-1 per day; orally), PVC (1000 mg kg^-1 per day; orally) and PVC + Vit E. After 40 days, rats were euthanized and epididymal sperms characteristics, embryo development and malondialdehyde (MDA) and testosterone levels were examined. The PVC decreased sperm count, motility and viability as well as testosterone level and increased sperms with damaged chromatin in comparison with controls. Also, the percentages of fertilization, two-cell embryos and blastocysts as well as MDA levels were decreased in PVC-treated rats. However, Vit E improved PVC-induced alterations in aforesaid parameters. The results indicated that PVC can reduce fertility potential in male rats probably through androgen and sperm quality and quantity reductions, while Vit E can exert protective effects in PVC-related reproductive toxicities.

External and Genetic Conditions Determining Male Infertility

We explain environmental and genetic factors determining male genetic conditions and infertility and evaluate the significance of environmental stressors in shaping defensive responses, which is used in the diagnosis and treatment of male infertility. This is done through the impact of external and internal stressors and their instability on sperm parameters and their contribution to immunogenetic disorders and hazardous DNA mutations. As chemical compounds and physical factors play an important role in the induction of immunogenetic disorders and affect the activity of enzymatic and non-enzymatic responses, causing oxidative stress, and leading to apoptosis, they downgrade semen quality. These factors are closely connected with male reproductive potential since genetic polymorphisms and mutations in chromosomes 7, X, and Y critically impact on spermatogenesis. Microdeletions in the Azoospermic Factor AZF region directly cause defective sperm production. Among mutations in chromosome 7, impairments in the cystic fibrosis transmembrane conductance regulator CFTR gene are destructive for fertility in cystic fibrosis, when spermatic ducts undergo complete obstruction. This problem was not previously analyzed in such a form. Alongside karyotype abnormalities AZF microdeletions are the reason of spermatogenic failure. Amongst AZF genes, the deleted in azoospermia DAZ gene family is reported as most frequently deleted AZF. Screening of AZF microdeletions is useful in explaining idiopathic cases of male infertility as well as in genetic consulting prior to assisted reproduction. Based on the current state of research we answer the following questions: (1) How do environmental stressors lessen the quality of sperm and reduce male fertility; (2) which chemical elements induce oxidative stress and immunogenetic changes in the male reproductive system; (3) how do polymorphisms correlate with changes in reproductive potential and pro-antioxidative mechanisms as markers of pathophysiological disturbances of the male reproductive condition; (4) how do environmental stressors of immunogenetic disorders accompany male infertility and responses; and (5) what is the distribution and prevalence of environmental and genetic risk factors.

Low Dose of Genistein Alleviates Mono-(2-Ethylhexyl) Phthalate-Induced Fetal Testis Disorder Based on Organ Culture Model

Mono-(2-ethylhexyl) phthalate (MEHP) and genistein have been classified as endocrine-disrupting chemicals (EDCs) which interfere with the differentiation and development of the male reproductive system. However, how these two EDCs would affect fetal rat testis development at a low dose was rarely studied. In this study, we established the organ culture system and applied it to evaluate testicular effects following multiple EDC exposure at a low dose. 15.5 days postcoitum fetal rat testes were dissected, cultured, and exposed to vehicle (control), GEN (1 μmol/L, G), MEHP (1 μmol/L, M), or GEN (1 μmol/L)+MEHP (1 μmol/L, G+M). Testicular cell markers, testosterone concentration, redox state, testicular histology, and testicular ultrastructure were evaluated. Our results showed that a low dose of MEHP suppressed the development of Sertoli cells, Leydig cells, and gonocytes by triggering oxidative injuries, which was consistent with the ultrastructural findings. However, coadministration of genistein at a low dose could partially attenuate MEHP-induced fetal testis damage through antioxidative action. Cotreatment of genistein at a low dose may have a promising future on its protecting role for attenuating other EDC-induced reproductive disorders during early life. Based on the results, it can be speculated that dietary intake of isoflavones may make the fetal testis less susceptible to phthalate-induced injury.

Enrichment of imidacloprid and its metabolites in lizards and its toxic effects on gonads

Soil contaminants can cause direct harm to lizards due to their regular swallowing of soil particles. As the world's fastest growing insecticide with long half-life in soil, the endocrine disrupting effect of neonicotinoids on lizards deserves more attention. In this report, we assessed the endocrine disrupting effect of imidacloprid on Eremias argus during 28 days of continuous exposure. Among the imidacloprid and its metabolites, only the metabolite 6-chloropyridic acid had a significant accumulation in the gonads and was positively correlated with its blood concentration. Imidacloprid might cause endocrine disrupting effects on lizards in two ways. First, the desnitro metabolites of imidacloprid could accumulate in the brain, inhibited the secretion of gonadotropin-releasing hormone, and ultimately affected the feedback regulation of hypothalamic-pituitary-gonadal related hormones. Secondly, imidacloprid severely inhibited the gene expression of the corresponding enzymes in the gonadal anti-oxidative stress system, causing histological damage to the gonads and ultimately affecting gonadal function. Specifically, exposure to imidacloprid resulted in abnormal arrangement of spermatogenic epithelial epithelium, hyperplasia of epididymal wall, and oligospermia of male lizard. Meanwhile, gene expressions of cyp17, cyp19, and hsd17β were severely inhibited in the imidacloprid exposure group, consistent with decreased levels of testosterone and estradiol in plasma. Imidacloprid exposure could cause insufficient androgen secretion and less spermatogenesis in male lizards. The risk of imidacloprid exposure to female lizards was not as severe as that of male lizards, but it still inhibited the expression of cyp19 in the ovaries and led to a decrease in the synthesis of estradiol. This study firstly reported the endocrine disruption of imidacloprid to lizards, providing new data for limiting the use of neonicotinoids.

Impact of environmental contaminants on reproductive health of male domestic ruminants: a review

Environmental contaminants are gaining more attention in the livestock sector lately due to their harmful effects on productivity and fertility of livestock. Recent research indicates that many domestic ruminants are becoming subfertile/infertile due to confounding reasons associated with management. Contaminants like metals, metalloids, herbicides, pesticides, insecticides, chemicals, or natural contaminants are present everywhere in day to day life and are becoming a threat to the livestock. Studies on a broad-spectrum of animals suggest that high doses of acute or low doses of chronic exposure to the contaminants lead to disruption of multi-organs/systems including reproductive function. The lowered reproductive efficiency in animals is attributed to the endocrine disruptor activities of the environmental contaminants on the gonads, affecting gametogenesis and steroidogenesis. In vitro studies on testicular cells and the semen suggest that spermatozoa are more susceptible to damage by environmental contaminants. The quality of the semen happens to be a critical factor in the livestock industry. Contaminants affecting gametogenesis and steroidogenesis may lead to devastating consequences to the livestock reproduction, and thus the production. However, there is a lack of collective data on the effect of such environmental contaminants on the fertility of male domestic ruminants. This review discusses the studies related to the impact of environmental contaminants on male fertility in large (bull and buffalo) and small (sheep and goat) ruminants by focusing on the underlying molecular interactions between the contaminants and gonads.

Cross-talk between autophagy and apoptosis regulates testicular injury/recovery induced by cadmium via PI3K with mTOR-independent pathway

Autophagy and apoptosis are two major modes of cell death. A balanced interplay between both is vital for phagocytic clearance of apoptotic testicular cells. Here, generating a SD rats model-treated with cadmium (Cd) to mimic environmental exposure on human, we show that autophagy and apoptosis present synchronous change trends in Cd-induced testicular injury/self-recovery. Further, the cross-talk of autophagy and apoptosis is investigated in four testicular cell lines (GC-1/GC-2/TM3/TM4 cells) respectively. Results reveal that Cd-exposure for five consecutive weeks induces reproductive toxicity in male rats. After one cycle of spermatogenesis within 8 weeks without Cd, toxic effects are ameliorated significantly. In vitro, we find that PI3K inhibitor 3-MA regulates apoptosis by inhibiting autophagy with mTOR-independent pathway in Cd-treated testicular cells. Conclusively, cross-talk between autophagy and apoptosis regulates testicular injury/recovery induced by Cd via PI3K with mTOR-independent pathway.

Triclosan treatment to pregnant albino rats affects offspring numbers and the liver of both the pregnant rats and their offspring, and these effects are ameliorated by co-treatment with bee honey

We have assessed the effects of the broad-spectrum bactericide triclosan on the liver of pregnant albino rats and their offspring, and evaluated the protective potential of bee honey, which has radical-scavenging properties. The study involved treatment of 72 pregnant rats followed by examination of the pregnant rats and their offspring. The pregnant rats were divided equally into six groups (I-VI), each of which was subdivided equally into two Subgroups (A and B). Rats in the A subgroups were gavaged with a daily dose of 1.26 ml distilled water (IA), 1 ml corn oil (IIA), 1.68 ml aqueous solution of Clover Blossom honey (IIIA), 0.3 mg triclosan (IVA), 13 mg triclosan (VA), or 1.68 ml aqueous solution of honey with 13 mg triclosan (VIA), throughout pregnancy. Rats in the B subgroups received the same treatments throughout pregnancy and for 14 days after delivery. At the end of the experiments, the offspring's numbers were recorded and blood samples were taken from the pregnant rats for analysis. The livers of the studied groups were subjected for; histological study, morphometric analysis, and biochemical estimation of markers of oxidative stress. The results showed that the acceptable daily intake of triclosan did not induce significant pathological changes in the liver while high dose of triclosan induced pathological changes in the livers and reduced the numbers of offspring. Co-administration of honey with triclosan ameliorated most pathological change. Therefore, decrease the exposure of the pregnant women to triclosan is encouraged or co-supplementation with bee honey if exposure could not be avoided.

RXFP2 as novel potential biomarker for abnormal differentiation induced by diethylstilbestrol in the gubernaculum of fetal mice

Environmental estrogens (EEs) have been correlated with abnormalities in the male urogenital system. However, the mechanism underlying the effect of these molecules remains unclear. In vitro and in vivo experiments were performed to examine the expression level and mechanism of relaxin family peptide receptor 2 (RXFP2) in the gubernaculum of fetal mice following diethylstilbestrol (DES) treatment. The in vivo results demonstrate that DES treatment increased the stillbirth rate gradually, decreased the gubernacular cone volume significantly, and disrupted the tissue structure, leading to incomplete testicular descent. In vitro experiments reveal that DES administration resulted in abnormal cellular morphology and structural disorder of gubernacular cells, which lost their original morphology in a dose-dependent manner. Moreover, DES-induced F-actin rearrangement and stress fiber formation in cultured cells. Protein quantitative analysis showed that the RXFP2 level in each experimental group was significantly lower than that of the normal group. In conclusion, DES affects the morphology and alters the gubernaculum structure, as well as the expression of RXFP2 protein. These data demonstrate that DES is toxic to gubernaculum in fetal mice, and that RXFP2 is associated with the abnormal gubernaculum morphology induced by DES. Taken together, these data suggest that RXFP2 may be a novel potential biomarker for abnormal differentiation of the gubernaculum.

Effects of Bisphenols on Testicular Steroidogenesis

Over the last decades, the adverse effects of human exposure to the so-called "endocrine disruptors" have been a matter of scientific debate and public attention. Bisphenols are synthetic chemicals, widely used in the manufacture of hard plastic products. Bisphenol A (BPA) is one of the best-known environmental toxicants proven to alter the reproductive function in men and to cause other health problems. Consumer concern resulted in "BPA free" products and in the development of bisphenol analogs (BPA-A) to replace BPA in many applications. However, these other bisphenol derivatives seem to have effects similar to those of BPA. Although a number of reviews have summarized the effects of BPA on human reproduction, the purpose of this article is to review the effects of bisphenols on testicular steroidogenesis and to explore their mechanisms of action. Testicular steroidogenesis is a fine-regulated process, and its main product, testosterone (T), has a crucial role in fetal development and maturation and in adulthood for the maintenance of secondary sexual function and spermatogenesis. Contradictory outcomes of both human and animal studies on the effects of BPA on steroid hormone levels may be related to various factors that include study design, dosage of BPA used in in vitro studies, timing and route of exposure, and other confounding factors. We described the main possible molecular target of bisphenols on this complex pathway. We report that Leydig cells (LCs), the steroidogenic testicular component, are highly sensitive to BPA and several mechanisms concur to the functional impairment of these cells.

Maternal Exposure to T-2 Toxin Induces Changes in Antioxidant System and Testosterone Synthesis in the Testes of Mice Offspring

Simple Summary

This study investigated the effects of maternal T-2 toxin exposure on the development of testis in the mice offspring. The detrimental effects were assessed by testicular weight, antioxidant capacity, and testosterone synthesis and secretion. Studies have shown that the toxin carried by the mother has bad effects on the testicular development of offspring at puberty, affecting the antioxidant system and testosterone synthesis in the testis, but the maternal exposure of T-2 toxin had no significant impact on the testes of offspring after sexual maturity, suggesting the recovery of reproductive function.

Abstract

T-2 toxin, the most toxic member of trichothecene mycotoxin, is widely distributed in cereals, and has been extensively studied, but few studies focus on the toxicity of maternal exposure to offspring. This study focused on the effects of maternal exposure to T-2 toxin (during gestation and lactation) on the testicular development of mice offspring. Dams were orally administered with T-2 toxin at 0, 0.005, or 0.05 mg/kg body weight from the late stage of gestation to the end of lactation. Testicular samples of the mice offspring were collected on the postnatal day 21, 28, and 56. The results showed significant decreases in body weight and testicular weight on the postnatal day 28. Moreover, significant inhibition of antioxidant system and testosterone synthesis was detected on the postnatal day 28. Furthermore, there were significant decreases in the gene expression levels of StAR and 3β-HSD, which are involved in testosterone synthesis. In general, present results demonstrated that maternal exposure to T-2 toxin during gestation and lactation led to bad effects on the capacity of antioxidant system and inhibited testosterone synthesis in testes during pre-puberty with no significant effects on post-puberty.