Leptin level and oxidative stress contribute to obesity-induced low testosterone in murine testicular tissue

Evaluating the Role of Gynecomastia Surgery in Improving Sexual Function and Hormonal Profiles

BACKGROUND

Patients with gynecomastia may experience hormonal imbalances and sexual dysfunctions, such as erectile and ejaculatory disorders.

OBJECTIVES

This study evaluates the changes in hormonal parameters and sexual function following gynecomastia surgery.

METHODS

Thirty-two male patients (aged 15-65) without systemic or genetic comorbidities underwent gynecomastia surgery. Preoperative and postoperative hormonal parameters free and total testosterone, estrogen (EST), prolactin (PRL), follicle-stimulating hormone, luteinizing hormone, sex hormone-binding globulin, and sexual function scores (International Index of Erectile Function [IIEF], Premature Ejaculation Diagnostic Tool [PEDT]) were assessed. A urologist blinded to the study evaluated patients andrologically.

RESULTS

The mean age of the patients was 25.69 ± 10.37 years. Postoperative PRL and EST levels significantly decreased (P = .03 and P < .001, respectively). All IIEF subscale scores showed significant postoperative improvements (P-values ranging from <.001 to .006). PEDT scores significantly decreased postoperatively (P < .001).

CONCLUSIONS

Surgical treatment of gynecomastia leads to significant improvements in hormonal parameters and sexual function. These benefits should be considered in surgical planning.

LEVEL OF EVIDENCE: 4

Do Lifestyle Interventions Mitigate the Oxidative Damage and Inflammation Induced by Obesity in the Testis?

Obesity results from a disproportionate accumulation of fat and has become a global health concern. The increase in adipose tissue is responsible for several systemic and testicular changes including hormone levels (leptin, adiponectin, testosterone, estrogen), inflammatory cytokines (increase in TNF-α and IL-6 and decrease in IL-10), and redox state (increase in reactive oxygen species and reduction in antioxidant enzymes). This results in poor sperm quality and compromised fertility in men with obesity. Lifestyle modifications, particularly diet transition to caloric restriction and physical exercise, are reported to reverse these negative effects. Nevertheless, precise mechanisms mediating these benefits, including how they modulate testicular oxidative stress, inflammation, and metabolism, remain to be fully elucidated. The main pathway described by which these lifestyle interventions reverse obesity-induced oxidative damage is the Nrf2-SIRT1 axis, which modulates the overexpression of antioxidant defenses. Of note, some of the detrimental effects of obesity on the testis are inherited by the descendants of individuals with obesity, and while caloric restriction reverses some of these effects, no significant work has been carried out regarding physical exercise. This review discusses the consequences of obesity-induced testicular oxidative stress on adult and pediatric populations, emphasizing the therapeutic potential of lifestyle to mitigate these detrimental effects.

The role of leptin in the male reproductive system

Leptin is a hormone produced from adipose tissue, targeting the hypothalamus and regulating energy expenditure, adipose tissue mass, and reproductive function. Leptin concentration reflects body weight and the amount of energy stored, as well as the level of reproductive hormones and male fertility. In this review, the aim was to focus on leptin signaling mechanisms and the significant influence of leptin on the male reproductive system and to summarize the current knowledge of clinical and experimental studies. The PubMed database was searched for studies on leptin and the male reproductive system to summarize the mechanism of leptin in the male reproductive system. Studies have shown that obesity-related, high leptin levels or leptin resistance negatively affects male reproductive functions. Leptin directly affects the testis by binding to the hypothalamic-pituitary-gonadal axis and the receptors of testicular cells, and thus the location of leptin receptors plays a key role in the regulation of the male reproductive system with the negative feedback mechanism between adipose tissue and hypothalamus. Based on the current evidence, leptin may totally inhibit male reproduction, and investigation of this role of leptin has established a potential interaction between obesity and male infertility. The mechanism of leptin in the male reproductive system should be further investigated and possible treatments for subfertility should be evaluated, supported by better understanding of leptin and associated signaling mechanisms.

Improvement of Late-Onset Hypogonadism Symptoms of Fermented Morinda citrifolia Extract in TM3 Leydig and TM4 Sertoli Cells

BACKGROUND/OBJECTIVES

Late-onset hypogonadism (LOH), characterized by declining testosterone levels with age, negatively affects the health of men, causing physical, psychological, and sexual dysfunction. Conventional testosterone replacement therapies have side effects, which has led to interest in natural alternatives. We investigated the effects of a standardized fermented Morinda citrifolia extract (FME) on oxidative stress-induced damage in TM3 Leydig and TM4 Sertoli cells. The cells were treated with H2O2 to simulate oxidative stress, followed by the FME treatment.

METHODS

Cytotoxicity assays, testosterone measurements, and gene and protein expression analyses were conducted to evaluate the restorative properties of FME.

RESULTS

The H2O2 treatment significantly decreased the cell viability, testosterone production, and the expression of proteins involved in testosterone synthesis and spermatogenesis, and the FME treatment improved testosterone production and restored the luteinizing hormone receptor, steroidogenic acute regulatory protein, CYP11A1, 3β-hydroxysteroid dehydrogenase, 17,20 desmolase, and 17β-hydroxysteroid dehydrogenase levels in the TM3 Leydig cells. It also reduced the expression of testosterone-degrading enzymes, aromatase and 5α-reductase. The FME treatment restored the levels of the androgen receptor and follicle-stimulating hormone receptor in the TM4 Sertoli cells.

CONCLUSIONS

FME alleviates oxidative stress-induced damage in Leydig and Sertoli cells by promoting testosterone synthesis and spermatogenesis while regulating testosterone metabolism. These findings suggest that FME could be a promising candidate for the management of LOH symptoms.

Effect of fluoride-induced testicular alteration in rats fed a high-fat diet

Previous research on the well-known environmental pollutant fluoride has demonstrated that fluoride exposure can lead to oxidative stress-related male infertility. Obesity is another public health issue that has a detrimental impact on male fertility. Previously, findings on fluoride toxicity in high-fat diet (HFD) conditions associated with oxidative stress have been evidenced. This study aimed to evaluate the impact of subchronic fluoride exposure (5 mg/kg) plus a HFD on testicular alteration in Wistar rats. Animals were divided into four groups (control, HFD, fluoride, and fluoride 5 mg/kg plus HFD). The HFD contained a 50% kcal increase in fat (saturated fat), after 90 days of co-exposure to fluoride plus HFD, the animals showed a significant decrease in the adiposity index. The co-exposed group showed oxidative damage assessed through decreased glutathione (GSH) concentration (p < 0.0001), increased concentrations of malondialdehyde (MDA) (p < 0.0001), and the oxidation of proteins (p < 0.0001) vs the control group. Finally, testicular histology exhibited a reduction in spermatogonia and spermatocytes. The results of the study indicate that under these conditions, subchronic co-exposure to fluoride under HFD conditions could protect against the accumulation of epididymal fat, however, oxidative alteration at the testicular level is maintained.

Positive association between serum bilirubin within the physiological range and serum testosterone levels

BACKGROUNDS

Research has demonstrated that elevated serum total bilirubin (STB) levels have a beneficial impact on various diseases, particularly metabolic syndrome. This study aims to investigate the association between STB levels and serum testosterone (STT) in order to determine if bilirubin plays a protective role in relation to testosterone deficiency (TD) risk.

METHODS

In this study, a total of 6,526 eligible male participants aged 20 years or older were analyzed, all of whom took part in the National Health and Nutrition Examination Survey (NHANES) conducted between 2011 and 2016. To investigate the relationship between STB and STT levels, we employed weighted multivariate regression models along with restricted cubic splines (RCS). Additionally, a subgroup analysis was conducted to explore the heterogeneity of this relationship across different subpopulations.

RESULTS

Among the participants, 1,832 individuals (28.07%) were identified as having testosterone deficiency (TD), defined as an STT level below 300 ng/dL. A significant positive correlation between STB and STT levels was observed in both crude and adjusted models (all P < 0.0001). The association between STB and STT levels was found to be statistically significant up to a threshold of 17.1 µmol/L, after which it became statistically insignificant(P for non-linearity = 0.0035). Weighted logistic regression analysis indicated that a 1 µmol/L increase in STB was associated with a 4% decrease in the likelihood of TD (odds ratio = 0.96, P < 0.0001). Subgroup analysis showed that the inverse relationship was limited to individuals aged 60 and over, non-smokers/drinkers, and obese individuals.

CONCLUSION

STB within the physiological range(17.1 µmol/L) was positively associated with STT in adult males. The potential protective role of bilirubin regarding testosterone levels merits further exploration.

1-DNJ Alleviates Obesity-Induced Testicular Inflammation in Mice Model by Inhibiting IKKβ/ NF-kB Pathway

Obesity is associated with chronic inflammation that affects various organs in the body, including the reproductive system, which is a key factor in male infertility. 1-Deoxynojirimycin (1-DNJ) is a natural alkaloid in mulberry leaves, which has anti-inflammatory capabilities, yet, it's effects on obesity-induced inflammation-related male infertility remain unclear. Therefore, this research investigates the underlying mechanism by which 1-DNJ may mitigate fertility impairment in male mice caused by obesity-related inflammation. Male mice with high-fat diet (HFD)-induced obesity were treated with 1-DNJ or metformin for 8 weeks. Metabolic profiles were evaluated by enzyme method. Reproductive capacity was assessed by sperm viability, motility and counts, immunohistochemistry was performed to evaluate the testicular damage caused by obesity and inflammation. The inflammation was assessed by measuring the levels of tumor necrosis factor α (TNFα), interleukin 1β (IL-1β), and interleukin 6 (IL-6). The activation of IκB kinase β (IKKβ) and nuclear factor κB (NF-κB) was examined using western blot and immunohistochemistry. HFD induced obesity in mice with obvious lipid metabolism disorder. The obese male mice had a decreased testosterone level, impaired sperm motility, and increased inflammatory factors. 1-DNJ treatment improved the testosterone level in the obese mice, ameliorated the testicular structure damage and improve sperm viability. In addition, 1-DNJ treatment inhibited IKKβ/NF-kB signaling pathway and reduced inflammation in obese mice. 1-DNJ can improve the fertility of obese men by reducing obesity as well as obesity-induced inflammation. These findings provide new insights for 1-DNJ to alleviate inflammation caused by obesity and provide future possibilities for treating male infertility.

High-fat diet disrupts the gut microbiome, leading to inflammation, damage to tight junctions, and apoptosis and necrosis in Nyctereutes procyonoides intestines

Given the burgeoning Nyctereutes procyonoides breeding industry and its growing scale, it is imperative to investigate the impact of high-fat diets on the health of these animals. This study involved 30 male Nyctereutes procyonoides of comparable weights (3 kg ±0.5), randomly assigned to either a control group or a high-fat diet group (n = 15 each). The latter group was fed a mixture of lard and basal diet in a 2:5 ratio, establishing a high-fat diet model in Nyctereutes procyonoides. This diet induced diarrhea and histopathological changes in the Nyctereutes procyonoides. Analysis of the small intestine contents using 16S rRNA sequencing revealed a high-fat diet-induced disruption in the gut microbiota. Specifically, Escherichia-Shigella emerged as the biomarker in the high-fat diet group (P = 0.049), while Vagococcus was prevalent in the control group (P = 0.049), indicating a significant increase in harmful bacteria in the high-fat diet group. Furthermore, this disrupted gut flora correlated with inflammation and oxidative stress, as evidenced by marked increases in TNF-α (P < 0.01), IL-1β (P < 0.05), and IL-6 (P < 0.05) levels, measured via q-PCR, Western blot, and oxidative stress assays. In addition, q-PCR analysis revealed significant upregulation of apoptosis and necrosis markers, including Bax, Caspase3, Caspase9, Caspase12, RIPK3, and RIPK1 (P < 0.01 to P < 0.001), and a concurrent downregulation of the anti-apoptotic gene Bcl-2 (P < 0.01) in the high-fat diet group, consistent with protein expression trends. These findings suggest that a high-fat diet alters the gut microbiome toward a more harmful bacterial composition, escalating inflammatory responses and intestinal tissue permeability, culminating in intestinal cell apoptosis and necrosis.IMPORTANCEThis study examines the impact of high-fat diets on Nyctereutes procyonoides. Our research established a Nyctereutes procyonoides model on a high-fat diet, revealing significant health impacts, such as diarrhea, histological anomalies, and alterations in the gut microbiota. These findings emphasize the importance of preventing health issues and promoting sustainable industry growth. They highlight the significant impact of diet on gut microbiota and overall animal health.

Dietary Patterns and Fertility

Diet has a key role in the reproductive axis both in males and females. This review aims to analyze the impacts of different dietary patterns on fertility. It appears that the Mediterranean diet has a predominantly protective role against infertility, while the Western diet seems to be a risk factor for infertility. Moreover, we focus attention also on dietary patterns in different countries of the World (Middle Eastern diet, Asian diet). In particular, when analyzing single nutrients, a diet rich in saturated fatty acids, cholesterol, animal proteins, and carbohydrates with high glycemic index is highly associated with male and female infertility. Finally, we evaluate the effects of vegetarian, vegan, and ketogenic diets on fertility, which seem to be still unclear. We believe that comprehension of the molecular mechanisms involved in infertility will lead to more effective and targeted treatments for infertile couples.

Toxic effects and potential mechanisms of zinc pyrithione (ZPT) exposure on sperm and testicular injury in zebrafish

Zinc pyrithione (ZPT) is widely recognized for its beneficial properties as an antifouling, antibacterial, and antifungal agent. Despite its positive industrial contributions, ZPT has been proven to exhibit toxicity towards various ecosystems, particularly affecting marine life. However, there is still a dearth of comprehensive research on ZPT toxicity and its toxicological mechanism in reproductive systems of aquatic organisms. In our study, we conducted a thorough analysis and unveiled a multitude of abnormalities in zebrafish sperm and testicular tissue caused by ZPT exposure, including a dose-dependent diminishing of testosterone levels, various sperm deformities, decreased sperm concentration and motility, and ROS-induced testicular tissue DNA damage. In addition, our study suggested that ZPT-induced testicular damage is associated with heightened oxidative stress, apoptosis, and possible hyperpolarization of the mitochondrial membrane. Through RNA-seq analysis, a total of 409 DEGs associated with ZPT-induced testicular injury were identified, and the hub gene was determined using a protein-protein interaction network (PPI). The genes and pathways uncovered in this study point to potential mechanisms of ZPT exposure on sperm and testicular injury in zebrafish.

Pyrroloquinoline quinone inhibits PCSK9-NLRP3 mediated pyroptosis of Leydig cells in obese mice

Abnormal lipid metabolism and chronic low-grade inflammation are the main traits of obesity. Especially, the molecular mechanism of concomitant deficiency in steroidogenesis-associated enzymes related to testosterone (T) synthesis of obesity dominated a decline in male fertility is still poorly understood. Here, we found that in vivo, supplementation of pyrroloquinoline quinone (PQQ) efficaciously ameliorated the abnormal lipid metabolism and testicular spermatogenic function from high-fat-diet (HFD)-induced obese mice. Moreover, the transcriptome analysis of the liver and testicular showed that PQQ supplementation not only inhibited the high expression of proprotein convertase subtilisin/Kexin type 9 (PCSK9) but also weakened the NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis, which both played a negative role in T synthesis of Leydig Cells (LCs). Eventually, the function and the pyroptosis of LCs cultured with palmitic acid in vitro were simultaneously benefited by suppressing the expression of NLRP3 or PCSK9 respectively, as well the parallel effects of PQQ were affirmed. Collectively, our data revealed that PQQ supplementation is a feasible approach to protect T synthesis from PCSK9-NLRP3 crosstalk-induced LCs' pyroptosis in obese men.

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.

Mitochondria Quality Control and Male Fertility

Mitochondria are pivotal to cellular homeostasis, performing vital functions such as bioenergetics, biosynthesis, and cell signalling. Proper maintenance of these processes is crucial to prevent disease development and ensure optimal cell function. Mitochondrial dynamics, including fission, fusion, biogenesis, mitophagy, and apoptosis, maintain mitochondrial quality control, which is essential for overall cell health. In male reproduction, mitochondria play a pivotal role in germ cell development and any defects in mitochondrial quality can have serious consequences on male fertility. Reactive oxygen species (ROS) also play a crucial role in sperm capacitation, but excessive ROS levels can trigger oxidative damage. Any imbalance between ROS and sperm quality control, caused by non-communicable diseases or environmental factors, can lead to an increase in oxidative stress, cell damage, and apoptosis, which in turn affect sperm concentration, quality, and motility. Therefore, assessing mitochondrial functionality and quality control is essential to gain valuable insights into male infertility. In sum, proper mitochondrial functionality is essential for overall health, and particularly important for male fertility. The assessment of mitochondrial functionality and quality control can provide crucial information for the study and management of male infertility and may lead to the development of new strategies for its management.

The effects of alcohol on testosterone synthesis in men: a review

INTRODUCTION

Testosterone concentrations in men decline with advancing age, with low testosterone concentrations being associated with multiple morbidities, an increased risk of early mortality, and a reduced quality of life. The purpose of this study was to examine the effects of alcohol on testosterone synthesis in men by investigating its effects on each level of the hypothalamic-pituitary-gonadal axis.

AREAS COVERED

Acute consumption of a low-to-moderate amount of alcohol increases testosterone concentrations in men, while consumption of a large volume of alcohol is associated with a reduction in serum testosterone concentrations. Elevated testosterone concentrations result from the increased activity of detoxification enzymes in the liver. Conversely, the primary mechanisms of action involved in the reduction of testosterone are increased hypothalamic-pituitary-adrenal axis activity, inflammation, and oxidative stress. When alcohol is consumed in excess, particularly chronically, it negatively affects testosterone production in men.

EXPERT OPINION

Since testosterone is an important component of men's health and wellbeing, current levels of alcohol consumption in many countries of the world require urgent attention. Elucidating the relationship between alcohol consumption and testosterone may be useful in identifying strategies to attenuate the testosterone-reducing effects of excessive or chronic alcohol consumption.

Anthocyanins Prevent AAPH-Induced Steroidogenesis Disorder in Leydig Cells by Counteracting Oxidative Stress and StAR Abnormal Expression in a Structure-Dependent Manner

Testosterone deficiency may increase the risk of sexual dysfunction and the failure of spermatogenesis. Oxidative stress that is derived from the destruction of homeostasis, disease, and exposure to contaminants can damage the steroidogenicity process in Leydig cells, resulting in a reduction in testosterone synthesis. Anthocyanins are a group of innoxious antioxidants widely recognized in food sources, and are an ideal candidate to relieve oxidative stress-related steroidogenesis disorder. However, there is still a major gap in our knowledge of the structure-function relationship of anthocyanin on the activity mentioned above. In the present study, four anthocyanins including cyanidin-3-glucoside (Cy-3-glu), delphinidin-3-glucoside (Dp-3-glu), pelargonidin-3-glucoside (Pg-3-glu), and cyanidin-3,5-diglucoside (Cy-3,5-diglu) were applied to reverse testosterone generation after employing 2,2'-Azobis(2-amidinopropane)-dihydrochloride (AAPH) as the inducer of oxidative stress in R2C cells. The results demonstrated that all four kinds of anthocyanins can inhibit ROS generation, alleviate mitochondrial membrane potential damage, and contribute to increased testosterone. Among them, Cy-3,5-diglu with diglycoside performed best on antioxidative ability and improved cell dysfunction and upregulated the expression of the steroidogenic acute regulatory protein (StAR). The molecular docking further revealed the direct combination between anthocyanins and StAR, suggesting that anthocyanins with monosaccharide were more likely to interact with StAR than with diglycoside. Taken together, these data indicate that recipient R2C cells under oxidative stress submitted to anthocyanins exhibited improved steroidogenesis in a structure-dependent manner. Anthocyanins could be considered the ideal ingredients against oxidative stress-induced testosterone deficiency.

Obesity: A Doorway to a Molecular Path Leading to Infertility

The dramatic rise in obesity has recently made it a global health issue. About 1.9 billion were overweight, and 650 million global populations were obese in 2016. Obese women suffer longer conception time, lowered fertility rates, and greater rates of miscarriage. Obesity alters hormones such as adiponectin and leptin, affecting all levels within the hypothalamic-pituitary-gonadal axis. Advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are inflammatory cytokines that may play an important role in the pathophysiology of ovarian dysfunction in obesity. In obese males, there are altered sperm parameters, reduced testosterone, increased estradiol, hypogonadism, and epigenetic modifications transmitted to offspring. The focus of this article is on the possible adverse effects on reproductive health resulting from obesity and sheds light on different molecular pathways linking obesity with infertility in both female and male subjects. Electronic databases such as Google Scholar, Embase, Science Direct, PubMed, and Google Search Engine were utilized to find obesity and infertility-related papers. The search strategy is detailed in the method section. Even though multiple research work has shown that obesity impacts fertility in both male and female negatively, it is significant to perform extensive research on the molecular mechanisms that link obesity to infertility. This is to find therapeutics that may be developed aiming at these mechanisms to manage and prevent the negative effects of obesity on the reproductive system.

An association between adropin hormone and total testosterone in obese men: a case-control study

BACKGROUND

Obesity is associated with low testosterone levels that could be caused by many mechanisms. Adropin, a peptide hormone, its levels are decreased in obesity and its receptors are expressed in the hypothalamus, the pituitary gland, and the testis. Adropin association to total testosterone in obese men is not detected yet. This study tries to find out possible associations between serum levels of adropin, adiponectin, total testosterone, and lipid profile in obese men.

METHODS

Serum levels of adropin, adiponectin, total testosterone, and lipid profile parameters were measured in 43 obese men and 40 age-matched normal-weight men.

RESULTS

Adropin, adiponectin, and testosterone levels were significantly lower in obese men versus normal-weight men. In all participants, positive correlations between adropin, adiponectin, and total testosterone were detected. Adropin is considered a predictor risk factor for testosterone.

CONCLUSIONS

This study suggests a possible causal relationship between adropin and total testosterone which needs further investigation.

TRIAL REGISTRATION

Clincialtrials.gov NCT03724825 , registered October 30th, 2018.

Adipose Tissue Dysfunction and Obesity-Related Male Hypogonadism

Obesity is a chronic illness associated with several metabolic derangements and comorbidities (i.e., insulin resistance, leptin resistance, diabetes, etc.) and often leads to impaired testicular function and male subfertility. Several mechanisms may indeed negatively affect the hypothalamic–pituitary–gonadal health, such as higher testosterone conversion to estradiol by aromatase activity in the adipose tissue, increased ROS production, and the release of several endocrine molecules affecting the hypothalamus–pituitary–testis axis by both direct and indirect mechanisms. In addition, androgen deficiency could further accelerate adipose tissue expansion and therefore exacerbate obesity, which in turn enhances hypogonadism, thus inducing a vicious cycle. Based on these considerations, we propose an overview on the relationship of adipose tissue dysfunction and male hypogonadism, highlighting the main biological pathways involved and the current therapeutic options to counteract this condition.

Erectile Dysfunction in Relation to Metabolic Disorders and the Concentration of Sex Hormones in Aging Men

Background: The aim of this study was to analyze the relationship between the prevalence of erectile dysfunction in men as diagnosed by the International Index of Erectile Function (IIEF) questionnaire and the respective levels of sex hormones and biochemical parameters, as well as indices of visceral fat accumulation and activity. Material and Methods: The study comprised 148 male (60–75 years) patients from primary care outpatient clinics in the city of Szczecin (Poland). The men were asked to complete a shortened survey questionnaire with sociodemographic data, as well as a shortened version of the IIEF (five items). Venous blood samples were collected. Total testosterone (TT), estradiol (E2), sex hormone-binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEAS), total cholesterol (ChT), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), fasting plasma glucose (FPG) and albumin were determined. Lipid accumulation product (LAP) and visceral adiposity index (VAI) were calculated. Results: A correlation was found in the analysis of LAP index values (OR = 1.017; p = 0.050). The analysis of hormone concentrations showed a correlation between the diagnosed trait and the value of TT (OR = 1.216; p = 0.046) and SHBG (OR = 1.020; p = 0.007). Conclusions: VAI and LAP have been shown to be good indicators for assessing erectile dysfunction in men over 60 years of age.

Oxidative Stress in Men with Obesity, Metabolic Syndrome and Type 2 Diabetes Mellitus: Mechanisms and Management of Reproductive Dysfunction

Reactive oxygen species (ROS) are critical physiological mediators of cellular function, including male fertility. When ROS exceed antioxidant regulation, oxidative stress occurs which is detrimental to cellular function. Oxidative stress has been found to be a central mediator of obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM), as well as with male infertility. Human studies have correlated testicular oxidative stress in obese males, and animal studies have further provided insight into potential mechanisms of action. Management of oxidative stress is not well defined. Appropriate nutrition and exercise can be recommended for all diabetic patients, and weight loss for obese patients with MetS and T2DM. Consideration of dietary supplements including micronutrients, antioxidants or medicinal herbs are recommended. Metformin may also offer benefits on testicular oxidative stress and fertility parameters. Significantly more research on causation, mechanisms, clinical assessments and appropriate management of infertility on obesity, MetS and T2DM is still required.

Animal models of male subfertility targeted on LanCL1-regulated spermatogenic redox homeostasis

Oxidative stress in spermatozoa is a major contributor to male subfertility, which makes it an informed choice to generate animal models of male subfertility with targeted modifications of the antioxidant systems. However, the critical male germ cell-specific antioxidant mechanisms have not been well defined yet. Here we identify LanCL1 as a major male germ cell-specific antioxidant gene, reduced expression of which is related to human male infertility. Mice deficient in LanCL1 display spermatozoal oxidative damage and impaired male fertility. Histopathological studies reveal that LanCL1-mediated antioxidant response is required for mouse testicular homeostasis, from the initiation of spermatogenesis to the maintenance of viability and functionality of male germ cells. Conversely, a mouse model expressing LanCL1 transgene is protected against high-fat-diet/obesity-induced oxidative damage and subfertility. We further show that germ cell-expressed LanCL1, in response to spermatogenic reactive oxygen species, is regulated by transcription factor specific protein 1 (SP1) during spermatogenesis. This study demonstrates a critical role for the SP1-LanCL1 axis in regulating testicular homeostasis and male fertility mediated by redox balance, and provides evidence that LanCL1 genetically modified mice have attractive applications as animal models of male subfertility.

Diet and Male Fertility: The Impact of Nutrients and Antioxidants on Sperm Energetic Metabolism

Diet might affect male reproductive potential, but the biochemical mechanisms involved in the modulation of sperm quality remain poorly understood. While a Western diet is considered a risk factor for male infertility, the Mediterranean diet seems to protect against male infertility; moreover, the role of a vegetarian habitus in the preservation of sperm quality is controversial. The aim of this review is to analyze the molecular effects of single nutrients on sperm quality, focusing on their involvement in biochemical mechanisms related to sperm bioenergetics. It appears that diets rich in saturated fatty acids (SFA) and low in polyunsaturated fatty acids (PUFA) negatively affect sperm quality, whereas unsaturated fatty acids supplementation ameliorates sperm quality. In fact, the administration of PUFA, especially omega-3 PUFA, determined an increase in mitochondrial energetic metabolism and a reduction in oxidative damage. Carbohydrates and proteins are also nutritional modulators of oxidative stress and testosterone levels, which are strictly linked to sperm mitochondrial function, a key element for sperm quality. Moreover, many dietary natural polyphenols differentially affect (positively or negatively) the mitochondrial function, depending on their concentration. We believe that an understanding of the biochemical mechanisms responsible for sperm quality will lead to more targeted and effective therapeutics for male infertility.

A comparative study between curcumin and curcumin nanoemulsion on high-fat, high-fructose diet-induced impaired spermatogenesis in rats

Objectives

Curcumin is a promising nutraceutical with reported diverse therapeutic properties, but of limited oral bioavailability. The current manuscript investigates the role of encapsulation of curcumin in nanoemulsion form in counteracting the adverse effect of chronic ingestion of a high-fat high-fructose diet (HFHF) by juvenile male rats regarding testicular abnormalities and declined spermatogenesis.

Methods

Curcumin nanoemulsion was administered orally to Wistar rats at a dose of 5 or 10 mg/kg and compared with curcumin powder, followed by a pharmacological and histological assessment.

Key findings

Results demonstrated that curcumin nanoemulsion was superior to curcumin powder, particularly in enhancing the percentage progressive motility of spermatozoa, normalization of essential and non-essential amino acids in semen, normalization of serum leptin and testosterone levels, as well as normalization of oxidative and nitrosative parameters. It was also proven to reduce testicular DNA fragmentation, while elevating testicular cellular energy. In addition, curcumin nanoemulsion administered at a dose of 10 mg/kg induced the highest level of spermatogenesis, delineated by histological examination of the seminiferous tubules.

Conclusions

It can be concluded that curcumin nanoemulsion administered at a dose of 10 mg/kg successfully ameliorates the adverse effects of a HFHF on spermatogenesis.

Novelkaraya gum micro-particles loaded Ganoderma lucidum polysaccharide regulate sex hormones, oxidative stress and inflammatory cytokine levels in cadmium induced testicular toxicity in experimental animals

Presented research aimed to develop a spray drying process without the use of organic solvents for the preparation of novel Karaya gum polymer microparticles (MPs) of Ganoderma lucidum polysaccharide (GLP). The prepared microparticles were characterized and evaluated. Prepared novel karaya gum micro-particles loaded Ganoderma lucidum polysaccharide (GLP MPs) were observed an effect on cadmium (CAD) induced testicular toxicity. A total of 40 rats (male) was divided into 4 groups viz. 1. Control group, 2. GLP MPs (250 mg/kg, 60 days of b.w per day), 3. CAD (60 days of 30 mg/l/day), 4. GLP MPs + CAD. CAD was responsible for altering the sex hormones, oxidative stress and inflammatory cytokines. Furthermore, elevated levels of indicator of oxidative stress, malondialdehyde, and a reduced action of SOD, GSH, and CAT (antioxidant enzymes), were observed in the tissues of the testicles of CAD- treated group. Such harmful occurrences were followed by an up-regulation in proinflammatory cytokines (TNF-α, IL-1β) levels, protein expression of Nrf2, and HO-1 expression was decreased. GLP MPs pre-treatment significantly abrogated these toxic effects which were confirmed histologically. This study concluded that pre-treatment with GLP MPs exerts a protective effect against CAD-induced male reproductive testicular toxicity.

Oxidative Stress-Induced Male Infertility: Role of Antioxidants in Cellular Defense Mechanisms

Male infertility is linked to several environmental and mutagenic factors. Most of these factors, i.e., lifestyle, radiations, and chemical contaminations, work on the fundamental principles of physics, chemistry, and biology. Principally, it may induce oxidative stress (OS) and produce free radicals within the cells. The negative effect of OS may enhance the reactive oxygen species (ROS) levels in male reproductive organs and impair basic functions in a couple's fertility. Evidence suggests that infertile men have significantly increased ROS levels and a reduced antioxidant capacity compared with fertile men. Although, basic spermatic function and fertilizing capacity depend on a delicate balance between physiological activity of ROS and antioxidants to protect from cellular oxidative injury in sperm, that is essential to achieve pregnancy. The ideal oxidation-reduction (REDOX) equilibrium requires a maintenance of a range of ROS concentrations and modulation of antioxidants. For this reason, the chapter focuses on the effects of ROS in sperm functions and the current concepts regarding the benefits of medical management in men with diminished fertility and amelioration of the effect to improve sperm function. Also, this evidence-based study suggests an increasing rate of infertility that poses a global challenge for human health, urging the need of health care professionals to offer a correct diagnosis, comprehension of the process, and an individualized management of the patients.

Proteomic analysis reveals proteins and pathways associated with declined testosterone production in male obese mice after chronic high-altitude exposure

OBJECTIVE

Obesity is common in highland areas owing to lifestyle alterations. There are pieces of evidence to suggest that both obesity and hypoxia may promote oxidative stress, leading to hypogonadism in males. These findings indicate an increased risk of hypogonadism in obese males following hypoxia exposure. However, the mechanisms underlying the disease process remain unclear. The current study aims to explore the mechanism of testosterone production dysfunction in obese male mice exposed to a chronic high-altitude hypoxia environment.

METHODS

An obese male mouse model was generated by inducing obesity in mice via a high-fat diet for 14 weeks, and the obese mice were then exposed to a high-altitude hypoxia environment for 24 days. Sera and testicular tissues were collected to detect serum lipids, sex hormone level, and testicular oxidative stress indicators. Morphological examination was performed to assess pathological alterations in testicular tissues and suborganelles in leydig cells. Proteomic alterations in testicular tissues were investigated using quantitative proteomics in Obese/Control and Obese-Hypoxia/Obese groups.

RESULTS

The results showed that chronic high-altitude hypoxia exposure aggravated low testosterone production in obese male mice accompanied by increased testicular oxidative stress and histological damages. In total, 363 and 242 differentially expressed proteins (DEPs) were identified in the two comparison groups, Obese/Control and Obese-Hypoxia/Obese, respectively. Functional enrichment analysis demonstrated that several significant functional terms and pathways related to testosterone production were altered in the two comparison groups. These included cholesterol metabolism, steroid hormone biosynthesis, peroxisome proliferator-activated receptor (PPAR) signaling pathway, oxidative stress responses, as well as retinol metabolism. Finally, 10 representative DEPs were selected for parallel reaction monitoring verification. Among them, StAR, DHCR7, NSDHL, CYP51A1, FDPS, FDX1, CYP11A1, ALDH1A1, and GPX3 were confirmed to be downregulated in the two groups.

CONCLUSIONS

Chronic hypoxia exposure could exacerbate low testosterone production in obese male mice by influencing the expression of key proteins involved in steroid hormone biosynthesis, cholesterol biosynthesis, oxidative stress responses and retinol metabolism.

Could parental high-fat intake program the reproductive health of male offspring? A review

High-fat diet (HFD) intake can cause overweight and obesity and has become a global public health concern in recent years. Nutritional adversity at vulnerable windows of development can affect developing cells and their functions, including germ cells. Evidence shows that parental HFD intake prior to conception and/or during gestation and lactation could program the reproductive health of male offspring, ultimately resulting in impairment of the first as well as subsequent generations. In male offspring, adipose tissue and hypothalamic-pituitary-gonadal axis imbalance can impair the production of gonadotropins, leading to dysfunction of testosterone production and pubertal onset. The gonads can be directly impaired through oxidative stress, causing poor testosterone production and spermatogenesis; low sperm count, viability, and motility; and abnormal sperm morphology, which results in low sperm quality. Parental HFD intake could also be a risk factor for prostate hyperplasia and cancer in advanced age. It can impact the reproductive pattern of male offspring resulting in impairments in the subsequent generations. The investigation of semen quality must be extended to epidemiological and clinical studies of the male offspring of overweight and/or obese parents in order to improve the quality of human semen. This review addresses the effects of parental HFD intake on the reproductive parameters of male offspring and discusses the possible underlying mechanisms.

High fat diet-induced- and genetically inherited- obesity differential alters DNA demethylation pathways in the germline of adult male rats

Obesity is a multifactorial condition with predominantly genetic and environmental causes and is an emerging risk factor for male infertility/subfertility. Epigenetic mechanisms are vulnerable to genetic and environmental changes. Our earlier studies have shown differential effects of genetically inherited (GIO) - and diet-induced- obesity (DIO) on DNA methylation in male germline. Contrary to DNA methylation is DNA demethylation, which also regulates the gene expression by activating transcription. The present study aimed to delineate the effects of obesity on the DNA demethylation pathway using two rat models: GIO (WNIN/Ob) and DIO (high-fat diet). We observed differential alterations in enzymes involved in DNA demethylation by oxidation (Tet1-3) pathway in testis in both groups. An increase in Tets in DIO group and a decrease in GIO group were noted. Analysis of oxidation pathway intermediates (5-hmC, 5-fC, and 5-caC) did not show any effect on testis in DIO group but an increase in 5-hmC and decrease in 5-caC levels in GIO group was observed. Analysis of transcript levels of enzymes related to deamination pathway in testis showed an increase (Gadd45a, Aicda, and Tdg) in DIO group and a decrease (Gadd45a, Aicda, and Tdg) in GIO group. Also, 5-hmC levels were differentially altered in the spermatozoa of both groups without any changes in Tet enzyme levels. These findings highlight differences in effects of GIO and DIO on DNA demethylation mechanisms in male germline, which could be due to differences in endocrine and metabolic profile as well as white fat distribution observed earlier in two groups.

Comparative protective effects of N-acetylcysteine and melatonin against obesity-induced testicular dysfunction in rats

N-acetylcysteine (NAC) and melatonin were reported to exert protective effects on testicular tissues. Thus, this study aimed to determine which of these is more efficient against obesity-induced testicular dysfunction in albino rats. A total of 32 adult male rats (195 ± 10 g) were divided into four groups: control, obese rats fed a high-fat diet (HFD), HFD+NAC (150 mg/kg per day, i.p.) and HFD+melatonin (10 mg/kg per day, i.p.), for 5 weeks. Testes and epididymis were weighed. Lipid profile, pituitary-testicular hormones, tumor necrosis factor α (TNFα), epididymal sperm parameters, testicular oxidant-antioxidant system, testicular and the epididymal histopathology and immunohistochemical localization for androgen receptors (AR) and Bax reaction were analyzed. Administration of NAC or melatonin significantly improved the lipid parameters, gonadal hormones, TNFα level, sperm count and abnormal morphology, oxidant-antioxidant system and the absolute testicular and epididymal mass with an enhancement of testicular architecture, AR expression and apoptosis as compared with that in the obese group. Additionally, as compared with the NAC group, the melatonin group had significantly reduced body mass index, total cholesterol, triglyceride, and TNFα and increased testosterone, sperm count, motility, superoxide dismutase activity, mitigated histomorphometrical changes, Bax expression, and increased testicular AR expression. Therefore, melatonin was more efficient than NAC in affording fortification against HFD-induced testicular dysfunction.

Porous SiO2 -coated ultrasmall selenium particles nanospheres attenuate cerulein-induce acute pancreatitis in mice by downregulating oxidative stress

OBJECTIVE

To investigate the potential therapeutic role of porous SiO₂ -coated ultrasmall selenium particles nanospheres (Se@SiO₂ nanospheres) pretreatment in acute pancreatitis (AP) and to investigate the related mechanism.

METHODS

C57BL/6 mice were randomized to the normal control (CON) group, the AP (induced by cerulein injection) (CAE) group, and AP pretreated with Se@SiO₂ nanocomposites at 1 and 2 mg/kg (CAE + 1 or 2 mg/kg Se@SiO₂ ) groups, respectively. Serum levels of amylase and lipase, inflammatory cytokines (interleukin [IL]-6, IL-1β and tumor necrosis factor [TNF]-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine (Cr) were measured, and histopathology was performed to examine the tissue samples of the pancreas, lungs, kidneys and liver. Immunofluorescence assay of reactive oxygen species (ROS), myeloperoxidase (MPO) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling were conducted, and levels of MPO, malondialdehyde, superoxide dismutase and glutathione were evaluated. Finally, Western blot analysis was used to evaluate protein expressions of Nrf2, HO-1, NQO1, TLR4, MyD88 and p-p65 in pancreatic tissue.

RESULTS

Se@SiO₂ nanospheres alleviated pathological damage to the pancreas, and reduced pancreatic enzymes and inflammatory cytokines. Injury to other organs such as the liver, lungs and kidneys was also alleviated, as indicated by decreased ALT, AST, BUN, and Cr levels as well as improved histopathology. Moreover, Se@SiO₂ nanospheres reduced oxidative stress, and ultimately inhibited TLR4/ MyD88/p-p65 pathway and increased the protein expressions of NQO1, Nrf2, and HO-1.

CONCLUSION

Se@SiO₂ nanospheres may alleviate AP by relieving oxidative stress and targeting the TLR4/Myd88/p-p65 and NQO1/Nrf2/HO-1 pathways.

A Brief Overview of Oxidative Stress in Adipose Tissue with a Therapeutic Approach to Taking Antioxidant Supplements

One of the leading causes of obesity associated with oxidative stress (OS) is excessive consumption of nutrients, especially fast-foods, and a sedentary lifestyle, characterized by the ample accumulation of lipid in adipose tissue (AT). When the body needs energy, the lipid is broken down into glycerol (G) and free fatty acids (FFA) during the lipolysis process and transferred to various tissues in the body. Materials secreted from AT, especially adipocytokines (interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α)) and reactive oxygen species (ROS), are impressive in causing inflammation and OS of AT. There are several ways to improve obesity, but researchers have highly regarded the use of antioxidant supplements due to their neutralizing properties in removing ROS. In this review, we have examined the AT response to OS to antioxidant supplements focusing on animal studies. The results are inconsistent due to differences in the study duration and diversity in animals (strain, age, and sex). Therefore, there is a need for different studies, especially in humans.

Leptin and inflammatory factors play a synergistic role in the regulation of reproduction in male mice through hypothalamic kisspeptin-mediated energy balance

BACKGROUND

Energy balance is closely related to reproductive function, wherein hypothalamic kisspeptin mediates regulation of the energy balance. However, the central mechanism of kisspeptin in the regulation of male reproductive function under different energy balance states is unclear. Here, high-fat diet (HFD) and exercise were used to change the energy balance to explore the role of leptin and inflammation in the regulation of kisspeptin and the hypothalamic-pituitary-testis (HPT) axis.

METHODS

Four-week-old male C57BL/6 J mice were randomly assigned to a normal control group (n = 16) or an HFD (n = 49) group. After 10 weeks of HFD feeding, obese mice were randomly divided into obesity control (n = 16), obesity moderate-load exercise (n = 16), or obesity high-load exercise (n = 17) groups. The obesity moderate-load exercise and obesity high-load exercise groups performed exercise (swimming) for 120 min/day and 120 min × 2 times/day (6 h interval), 5 days/week for 8 weeks, respectively.

RESULTS

Compared to the mice in the normal group, in obese mice, the mRNA and protein expression of the leptin receptor, kiss, interleukin-10 (IL-10), and gonadotropin-releasing hormone (GnRH) decreased in the hypothalamus; serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels and sperm quality decreased; and serum leptin, estradiol, and tumor necrosis factor-α (TNF-α) levels and sperm apoptosis increased. Moderate- and high-load exercise effectively reduced body fat and serum leptin levels but had the opposite effects on the hypothalamus and serum IL-10 and TNF-α levels. Moderate-load exercise had anti-inflammatory effects accompanied by increased mRNA and protein expression of kiss and GnRH in the hypothalamus and increased serum FSH, LH, and testosterone levels and improved sperm quality. High-load exercise also promoted inflammation, with no significant effect on the mRNA and protein expression of kiss and GnRH in the hypothalamus, serum sex hormone level, or sperm quality. Moderate-load exercise improved leptin resistance and inflammation and reduced the inhibition of kisspeptin and the HPT axis in obese mice. The inflammatory response induced by high-load exercise may counteract the positive effect of improving leptin resistance on kisspeptin and HPT.

CONCLUSION

During changes in energy balance, leptin and inflammation jointly regulate kisspeptin expression on the HPT axis.

Mobility and Biomechanical Functions in the Aging Male: Testosterone and the Locomotive Syndrome

In the current aging society, the occurrence of the locomotive syndrome, a condition in which the locomotive organs are impaired, is increasing. The locomotive system includes support (bones), mobility and impact absorption (joints and intervertebral disks), drive and control (muscles, nerves), and network (blood vessels). The impairment of any of those systems can lead to a major decrease in quality of life. In recent years, several studies on methods to improve and prevent conditions impairing the locomotive syndrome have been conducted. Almost in parallel with the structure supporting mobility and body functions, testosterone levels decrease with age. Testosterone is a hormone-regulating several pathways affecting each aspect of the locomotive syndrome. Testosterone is regulated by the pituitary gland triggering several processes in the body through genomic and non-genomic pathways, affecting muscles, bones, nerves, joints, intervertebral discs, and blood vessels. The purpose of this review is to investigate the role of testosterone in each of the systems involved in the locomotive syndrome.

Cratoxylum formosum dyer extract alleviates testicular damage in hypertensive rats

The effects of a Cratoxylum formosum (Jack) Dyer ssp. (CF) extract on testicular damage were assessed in hypertensive rats. N^ω -nitro-L-arginine methyl ester hydrochloride (L-NAME; 40 mg kg^-1  day^-1 ) was administered for 5 weeks to induce hypertension in male Sprague-Dawley rats, and treated with CF extract (100, 300 or 500 mg kg^-1  day^-1 ) or sildenafil (5 mg kg^-1  day^-1 ) during the final 2 weeks (n = 8/group). Biochemical components of the CF extract were identified and mainly contained phenolic compounds. The CF extract significantly reduced systolic blood pressure and alleviated impaired sperm quality and seminiferous tubular morphology in hypertensive rats. CF extract restored reduced serum testosterone and protein expression of steroidogenic acute regulatory protein (StAR), nuclear factor erythroid-related factor 2 (Nrf2), and haem oxygenase 1 (HO-1) in L-NAME rats. Hypertensive rats presented decreased antioxidant enzyme activities, and increased testicular and plasma malondialdehyde (MDA) levels and superoxide production, all of which were normalised by CF extract. Furthermore, endothelial nitric oxide synthase (eNOS) expression in testicular tissue and plasma nitrate/nitrite levels were restored in hypertensive rats administered CF extract. Conclusion: CF extract alleviated testicular damage in hypertensive rats. Potential molecular mechanisms may involve suppression of oxidative stress and restoration of StAR, Nrf2, HO-1 and eNOS expression in hypertensive rats.

Cinnamomum zeylanicum alleviate testicular damage induced by high fat diet in albino rats; histological and ultrastructural studies

Hyperlipidemia has been related to sever health outcome include cardiovascular complication, metabolic disorders and infertility. Moreover, obesity has also been linked to dangerous effects on testicular morphology, spermatogenesis and sperm malformation. Many studies using different herbal medicines exert protective and therapeutic effect on the testes, spermatogenesis and fertility in animals fed high fat diet. Objective: this study aimed to find out the protective effect of cinnamon on testes of albino rat fed high fat diet (HFD). Forty adult male albino rats were selected and equally divided into 4 groups. Group 1: animals of this group were fed standard diet. Group 2: rats were fed standard diet and cinnamon "15% weight by weight, w/w" for 8 weeks. Group 3: animals in this group were fed HFD (2% cholesterol, 15 % sucrose, 15% corn, 15% cocoa butter, starch and 4.7% cellulose) for 8 weeks. Group 4: animals in this group were fed HFD and cinnamon. At the end of 4 weeks half animals were sacrificed and the rest of animals were sacrificed at the end of 8 weeks and blood samples were collected to assay the testosterone level. As well as testes were taken and prepared for both histological and ultrastructure studies. Histological examination of testicular tissue of HFD-fed animals revealed many pathological changes include degenerated seminiferous tubules, distorted germinal layers and interstitial tissue appeared degenerated with intertubular hemorrhage. Ultrastructural observations showed severe degenerated features including both different types of spermatogonia and interstitial tissue. On the other hand, both histological and ultrastructural alterations were substantially but not completely protect in obese animals fed HFD and cinnamon for 4 weeks while advanced degree of improvement tissue appeared after 8 weeks of the same treatment. As well as, significantly increase in the level of testosterone was recorded when compared with HFD-fed animals. The present work concluded that cinnamon dietary uptake may improve testicular damage induced by HFD as it has anti-inflammatory, anti-obesity and antioxidant activities.

Combined effects of obesity and di-(2-ethylhexyl) phthalate on testosterone levels and kisspeptin/GPR54 expression in hypothalamus and testes of male mice

BACKGROUND

This study evaluated whether obese male mice exposed to di-(2-ethylhexyl) phthalate (DEHP) showed synergistic effects on testosterone levels and the potential underlying mechanism.

METHODS

Forty-eight male mice were assigned to six groups for 12-week treatments as follows: normal, DEHP100, diet-induced obesity (DIO), DIO + DEHP30, DIO + DEHP100, and DIO + DEHP300. Serum hormone levels, including testosterone (T), luteinizing hormone (LH), and leptin, were detected by ELISA. The levels of Ob-R, kisspeptin, and GPR54 protein expression in hypothalamus and testicular tissues were measured by western blot.

RESULTS

There were significantly lower levels of serum T and LH, higher levels of serum leptin and Ob-R, and kisspeptin and GPR54 protein expression were reduced in hypothalamus and testicular tissues in the DIO and DEHP groups compared with controls. Moreover, serum T and leptin levels were more severe in the combined DIO and DEHP exposure group than in the single exposure groups. Serum LH levels and GPR54 expression in the testis were significantly decreased in DIO + DEHP300 mice compared with DIO mice (p < 0.05).

CONCLUSION

Obesity- and DEHP-only exposure had adverse effects on testosterone levels in mice, which may be due to high leptin levels and decreased Ob-R, kisspeptin, and GPR54 expression. Obesity combined with DEHP exposure had an additive adverse effect on testosterone levels in mice. One of the potential mechanisms is higher leptin levels and decreased GPR54 expression in the testes.

Transcriptome Analysis of Testis from HFD-Induced Obese Rats (Rattus norvigicus) Indicated Predisposition for Male Infertility

Obesity is a worldwide life-threatening metabolic disorder, associated with various chronic diseases, including male infertility. Obesity was induced by high fat diet (HFD), and testis RNA was used for the transcriptome analysis using RNAseq via Illumina NovaSeq 6000 System and NovaSeq 6000 Kit. Gene expression level was estimated as FPKM (Fragments Per Kilobase of transcript per Million mapped reads). Differential expressed genes (DEGs) were annotated against gene ontology (GO) and KEGG databases. More than 63.66 million reads per sample were performed with 100 bp cutoff and 6 Gb sequencing depth. Results of this study revealed that 267 GO terms (245 biological processes (BP), 14 cellular components (CC), eight molecular functions (MF)), and 89 KEGG pathways were significantly enriched. Moreover, total numbers of 136 genes were differentially expressed (107 upregulated, 29 downregulated) with |FC| ≥ 2 and bh adjusted <0.05. Interesting DEGs were detected, including obesity and lipid metabolism-related genes, immune response-related genes, cytochrome P450 genes, including aromatase were upregulated, whereas genes related to male fertility and fertilization, cell adhesion, and olfactory receptors were downregulated. The combined expression pattern of the DEGs in obese animals indicated an increase in cholesterol metabolism. Furthermore, high aromatase activity enhances the testosterone turnover into estradiol and lowers the testosterone/estradiol (T/E) ratio, which ultimately reduces fertility. In addition, downregulation of cadherens junction components genes leads to the pre-mature release of sperm from Sertoli cells resulting in the reduction of fertility. Moreover, the downregulation of olfactory receptor genes reduces the chemotaxis capacity of sperms in tracking the oocyte for fertilization, which reduces male fertility. Furthermore, various obesity molecular markers were detected in our transcriptome. The results of this study will enhance our understanding of the molecular network of obesity development, development of obesity novel molecular diagnosis markers, molecular bases of obesity-induced infertility, and the development of anti-obesity drugs.

Green Coffea arabica Extract Ameliorates Testicular Injury in High-Fat Diet/Streptozotocin-Induced Diabetes in Rats

Diabetes mellitus (DM) is a chronic endocrine disease characterized by persistent hyperglycemia. Oxidative damage, inflammatory cytokines, and apoptotic cell death play a major role in the induction and progression of male testicular damage. Plant-derived phytochemicals such as green coffee (Coffea arabica) can possess antidiabetic effects with little toxicity. The current study is aimed at investigating the therapeutic roles of green coffee in diabetic testicular injury stimulated by high-fat diet/streptozotocin administration. Diabetes mellitus was induced by a high-fat diet and a single dose of streptozotocin (STZ) (35 mg kg-1) in male albino rats. Diabetic animals were orally given two different concentrations of green coffee (50 mg kg-1 and 100 mg kg-1) for 28 days. The levels of testosterone, luteinizing hormone, and follicle-stimulating hormone and parameters of oxidative stress, inflammation, and apoptosis were measured. mRNAs and protein levels were detected quantitatively by real-time PCR and ELISA, respectively. In the diabetic group, the levels of testosterone, luteinizing hormone, and follicle-stimulating hormone showed a significant reduction while they increased significantly after green coffee treatment. A significant increase of antioxidant markers glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase along with decreased levels of lipid peroxides and nitric oxide was observed after green coffee treatment in the diabetic group. Finally, the levels of IL-1β, TNF-α, Bax, and caspase-3 were also decreased in both treated groups (metformin and green coffee) when compared to the diabetic group. We conclude that testicular oxidative impairment induced by a high-fat diet (HFD) and STZ can be reversed by green coffee. Administration of green coffee could represent a promising therapeutic agent which can help the treatment of type 2 DM-induced testicular dysfunction.

Gut microbiota dysbiosis might be responsible to different toxicity caused by Di-(2-ethylhexyl) phthalate exposure in murine rodents

Di-(2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer, which can enter the body through a variety of ways and exerted multiple harmful effects, including liver toxicity, reproductive toxicity and even glucose metabolism disorder. Many studies have suggested that changes of gut microbiota are closely related to the occurrence of various diseases, but the effects of DEHP exposure on gut microbiota are still unclear. It was found in this study that the damage to different tissues by DEHP on two strains each from two different species of male rodents before puberty was dose and time of exposure dependent, and also depending on the strain and species of rodent. Sprague-Dawley (SD) rats showed highest sensitivity to DEHP exposure, with most severe organ damage, highest Th1 inflammatory response and most significant body weight gain. Correspondingly, the gut microbiota of SD rats showed most significant changes after DEHP exposure. Only SD rats, but not Wistar rats, BALB/c and C57BL/6J mice showed an increase in Firmicutes/Bacteroidetes ratio and Proteobacteria abundance in the fecal samples, which are known to associate with obesity and diabetes. This is consistent with the increasing body weight gain which was only found in SD rats. In addition, the decrease in the level of butyrate, increase in the abundance of potential pathogens and microbial genes linked to colorectal cancer, Parkinson's disease, and type 2 diabetes in the SD rats were associated with issue and functional damages and Th1 inflammatory response caused by DEHP exposure. We postulate that the differential effects of DEHP on gut microbiota may be an important cause of the differences in the toxicity on different strains and species of rodents to DEHP.

Adenosine accumulation causes metabolic disorders in testes and associates with lower testosterone level in obese mice

Overweight and obese men face numerous health problems, including type 2 diabetes, subfertility, and even infertility. However, few studies have focused on the effects of nutritional status and obesity-related regulatory signals on fertility deficiency. Our previous observations have shown that the elevation of plasma 5'-adenosine monophosphate (5'-AMP) and the accumulation of adenosine in liver and muscle of obese diabetic db/db mice are related to insulin resistance. Here, we found that adenosine accumulation in testis is a common marker of both genetic obesity and high-fat-diet induced obese mice. An messenger RNA sequencing analysis indicated that 78 upregulated genes and 155 downregulated genes in the testis of 5'-AMP-treated mice overlapped with the same genes in the testis of ob/ob mice, and these genes belonged to the clusters of steroid metabolic process and regulation of hormone levels, respectively. Serum testosterone was reduced in ob/ob and 5'-AMP-treated mice. Metabolomic analysis based on ¹ H nuclear magnetic resonance showed that the testicular metabolic profiles of ob/ob mice were similar to those of 5'-AMP treated mice. Exogenous 5'-AMP inhibited the phosphorylation of AKT and mammalian target of rapamycin signal transduction and reduced the proliferating cell nuclear antigen expressions in testes. Our results suggest that the accumulation of adenosine causes metabolic disorders in testes and associates lower testosterone level in obese mice.

Effect of Different Exercise Loads on Testicular Oxidative Stress and Reproductive Function in Obese Male Mice

This study is aimed at investigating the effect of different exercise loads on the reproductive function of obese male mice and the underlying mechanisms. Male mice with high-fat diet-induced obesity were divided into obesity control (OC), obesity moderate-load exercise (OME), and obesity high-load exercise (OHE) groups. The OME and OHE groups were subjected to swimming exercise 5 days per week over a duration of 8 weeks, with the exercise load progressively increased to 2 h per day in the OME group and 2 h twice per day in the OHE group. In the OC group mice without exercise regimen, we observed a decrease in mRNA expression of antioxidant enzymes, increase in free radical products, upregulation of mRNA and protein expression of nuclear factor-κB and proinflammatory cytokines, inhibition of mRNA and protein expression of testosterone synthases, decrease in the serum testosterone level and sperm quality, and increase in sperm apoptosis. Although both moderate-load exercise and high-load exercise reduced body fat, only moderate-load exercise effectively alleviated obesity-induced oxidative stress, downregulated the expression of nuclear factor-κB and proinflammatory cytokines, and reversed the decrease in mRNA and protein expression of testosterone synthases, serum testosterone level, and sperm quality. These changes were not observed in the OHE group mice. Obesity-induced testicular oxidative stress and inflammatory response decreased testosterone synthesis and sperm quality. Moderate-load exercise alleviated the negative effect of obesity on male reproductive function by decreasing testicular oxidative stress and inflammatory responses. Although high-load exercise effectively reduced body fat, its effects on alleviating oxidative stress and improving male reproductive function were limited.

A paternal hypercaloric diet affects the metabolism and fertility of F1 and F2 Wistar rat generations

Increased fat and carbohydrate intakes based on the Western diet are important lifestyle modifications that lead to hypercaloric inputs, obesity, and male fertility negative effects. Epigenetic transmission may also predispose descended generations to chronic diseases, such as obesity, type 2 diabetes, behavioral, and reproductive disorders. The present study sought to evaluate the influence of a high-fat-high-sugar (HFHS) diet supplied to Wistar rats from 25 to 90 days of life on reproductive and metabolic parameters in male generations F0, F1, and F2. The standard group received the normocaloric - Nuvilab Quimtia® -3.86 kcal/kg. The hypercaloric diet (HD) group received the HFHS diet - PragSoluções® -4.77 kcal/kg. Body weight, adiposity, F1 and F2 prepubertal age evaluations, oral glucose tolerance test, insulin tolerance test, organ weights, sperm count and morphology assessments, and histometric testicular analyses were performed. The HFHS diet promoted dyslipidemia, higher adiposity, lower relative organ weights, and higher mean kidney weight, decreased mean testicle and parenchyma weights and lower height of seminiferous epithelium (HE) for the F0 generation. F1 and F2 offspring of HD group displayed early preprepubertal development, although did not alter the metabolic parameters. Decreased HE and tubular testicular compartment volumetric density and increased intertubular testicular compartment volumetric density and volume in the F1 generation of HD group were observed. Alterations in histometry of intertubular testicular compartment were also noted. It is concluded that the HFHS experimental model altered only paternal metabolic parameters. However, reproductive parameters of the three generations were affected.

A chronic high-fat diet causes sperm head alterations in C57BL/6J mice

A chronic-positive energetic balance has been directly correlated with infertility in men, but the involved mechanisms remain unknown. Herein we investigated weather in a mouse model a chronic feeding with a diet supplemented with chicken fat affects sperm head morphology. To accomplish this, we fed mice for 16 weeks with either control food (low-fat diet, LFD) or control food supplemented with 22% chicken fat (high-fat diet, HFD). At the end of the feeding regimen, we measured: redox and inflammatory changes, cholesterol accumulation in testis and analyzed testicular morphological structure and ultra-structure and liver morphology. We found that the mice fed HFD resembled some features of the human metabolic syndrome, including systemic oxidative stress and inflammation, this group showed an increment in the following parameters; central adiposity (adiposity index: 1.07 ± 0.10 vs 2.26 ± 0.17), dyslipidemia (total cholesterol: 153.3 ± 2.6 vs 175.1 ± 8.08 mg/dL), insulin resistance (indirect Insulin resistance index, TG/HDL-c: 2.94 ± 0.33 vs 3.68 ± 0.15) and fatty liver. Increased cholesterol content measured by filipin was found in the testicles from HFD (fluorescence intensity increase to 50%), as well as an alteration of spermiogenesis. Most remarkably, a disorganized manchette-perinuclear ring complex and an altered morphology of the sperm head were observed in the spermatozoa of HFD-fed mice. These results add new information to our understanding about the mechanisms by which systemic oxidative stress and inflammation may influence sperm-head morphology and indirectly male fertility.

Proteomic alterations underlie an association with teratozoospermia in obese mice sperm

BACKGROUND

Obesity is a worldwide crisis impairing human health. In this condition, declines in sperm quality stem from reductions in sperm concentration, motility and increase in sperm deformity. The mechanism underlying these alterations remains largely unknown. This study, determined if obesity-associated proteomic expression patterns in mice sperm parallel those in spermatozoa obtained from obese humans.

METHODS

An obese mouse model was established via feeding a high-fat diet (HFD). Histological analysis identified testicular morphology and a computer assisted semen analyzer (CASA) evaluated sperm parameters. Proteome analysis was performed using a label-free quantitative LC-MS/MS system. Western blot, immunohistochemical and immunofluorescent analyses characterized protein expression levels and localization in testis, sperm and clinical samples.

RESULTS

Bodyweight gains on the HFD induced hepatic steatosis. Declines in sperm motility accompanied sperm deformity development. Differential proteomic analysis identified reduced cytoskeletal proteins, centrosome and spindle pole associated protein 1 (CSPP1) and Centrin 1 (CETN1), in sperm from obese mice. In normal weight mice, both CSPP1 and CETN1 were localized in the spermatocytes and spermatids. Their expression was appreciable in the post-acrosomal region parallel to the microtubule tracks of the manchette structure in spermatids, which affects spermatid head shaping and morphological maintenance. Moreover, CSPP1 was localized in the head-tail coupling apparatus of the mature sperm, while CETN1 expression was delimited to the post-acrosomal region within the sperm head. Importantly, sperm CSPP1 and CETN1 abundance in both the overweight and obese males decreased in comparison with that in normal weight men.

CONCLUSION

These findings show that regionally distinct expression and localization of CETN1 and CSPP1 is strongly related to spermiogenesis and sperm morphology maintaining. Obesity is associated with declines in the CETN1 and CSPP1 abundance and compromise of both sperm morphology in mice and relevant clinical samples. This parallelism between altered protein expression in mice and humans suggests that these effects may contribute to poor sperm quality including increased deformity.

Marjoram and sage oils protect against testicular apoptosis, suppressed Ki-67 expression and cell cycle arrest as a therapy for male infertility in the obese rats

Alterations in testicular apoptosis, cell cycle progression and proliferation rate in dietary-induced obese male rats and role of oral administration of marjoram (0.16 ml/kg BW) and sage (0.05 ml/kg BW) oils were evaluated. Results showed increased body weight, serum leptin, testicular lipid peroxidation, protein oxidation and nitric oxide, with reduction in serum testosterone, sperm count and endogenous enzymatic and non-enzymatic antioxidants in testis of the obese rats. Flow cytometry results revealed increased number of annexin-V (+ve) cells with activation of apoptotic proteins (Bax, caspase-3) and reduction of anti-apoptotic Bcl-2. Cell cycle arrest at phases S and G2/M with decline in expression of Bcl-2 and germ cell proliferation marker ki-67 was also validated, indicating lowered spermatogenesis in the obese rats. Supplementation of marjoram or sage oils displayed normalized body weight, sperm count, germ cells apoptosis and proliferation, suggesting the two oils as a new therapeutic approach against obesity promoted male infertility. PRACTICAL APPLICATIONS: Obese men have a greater chance of fertility problems compared to those with normal weight. Obesity-associated oxidative stress and free radicals production have shown to adversely affect sperm quality with activation of pro-apoptotic pathways, allowing germ cell death. Marjoram and sage essential oils are now being widely studied due to their antioxidant and radical scavenging properties. Our findings indicated effectiveness of the two oils for combating body weight gain, testicular oxidative stress, and apoptosis, which seemed to aid in increasing sperm count. The outcomes of this study may help scientists to formulate novel medications for improving fertility problems in men.

Sulforaphane Protects the Male Reproductive System of Mice from Obesity-Induced Damage: Involvement of Oxidative Stress and Autophagy

(1) Background: In recent decades, the prevalence of obesity has grown rapidly worldwide, thus causing many diseases, including male hypogonadism. Sulforaphane (SFN), an isothiocyanate compound, has been reported to protect the reproductive system. This research investigated the protective effect of SFN against obesity-induced impairment in the male reproductive system and explored the potential mechanism involved in mice. (2) Methods: One hundred thirty mice were divided into 5 groups (Control, DIO (diet-induced obesity), DIO + SFN 5 mg/kg, DIO + SFN 10 mg/kg, and DIO + SFN 20 mg/kg). The effects of SFN on the male reproductive system were determined based on the sperm count and motility, relative testes and epididymis weights, hormone levels, and pathological analyses. Oxidative stress was determined by measuring malondialdehyde (MDA), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione (GSH), H₂O₂, catalase (CAT), and glutathione peroxidase (GSH-PX) levels. Protein expression of nuclear factor erythroid-2 related factor 2 (Nrf2), Kelch-like ECH-associated protein-1 (Keap1), Microtubule-associated protein light chain 3 (LC3), Beclin1, and P62 were determined by western blotting. (3) Results: High-fat diet (HFD)-induced obesity significantly decreased relative testes and epididymis weights, sperm count and motility, and testosterone levels but increased leptin and estradiol levels. SFN supplementation ameliorated these effects. Additionally, SFN administration inhibited the obesity-induced MDA accumulation and increased the SOD level. Western blot indicated that SFN had an important role in the downregulation of Keap1. Moreover, SFN treatment attenuated obesity-induced autophagy, as detected by LC3 and Beclin1. (4) Conclusions: SFN ameliorated the reproductive toxicity associated with obesity by inhibiting oxidative stress mediated by the nuclear factor erythroid-2 related factor 2/ antioxidant response element (Nrf2/ARE) signaling pathway and recovery of normal autophagy.