Effect of quercetin on cadmium chloride-induced impairments in sexual behaviour and steroidogenesis in male Wistar rats

Prevention of Male Late-Onset Hypogonadism by Natural Polyphenolic Antioxidants

Androgen production primarily occurs in Leydig cells located in the interstitial compartment of the testis. In aging males, testosterone is crucial for maintaining muscle mass and strength, bone density, sexual function, metabolic health, energy levels, cognitive function, as well as overall well-being. As men age, testosterone production by Leydig cells of the testes begins to decline at a rate of approximately 1% per year starting from their 30s. This review highlights recent findings concerning the use of natural polyphenolics compounds, such as flavonoids, resveratrol, and phenolic acids, to enhance testosterone production, thereby preventing age-related degenerative conditions associated with testosterone insufficiency. Interestingly, most of the natural polyphenolic antioxidants having beneficial effects on testosterone production tend to enhance the expression of the steroidogenic acute regulatory protein (Star) gene in Leydig cells. The STAR protein facilitates the entry of the steroid precursor cholesterol inside mitochondria, a rate-limiting step for androgen biosynthesis. Natural polyphenolic compounds can also improve the activities of steroidogenic enzymes, hypothalamus-pituitary gland axis signaling, and testosterone bioavailability. Thus, many polyphenolic compounds such as luteolin, quercetin, resveratrol, ferulic acid phenethyl ester or gigantol may be promising in delaying the initiation of late-onset hypogonadism accompanying aging in males.

Effects of garlic (Allium sativum L) and Citrullus colocynthis (L.) Schrad individually and in combination on male reproductive damage due to diabetes: suppression of the AGEs/RAGE/Nox-4 signaling pathway

BACKGROUND

Diabetes Mellitus is associated with disturbances in male reproductive function and fertility. Studies have shown that oxidative stress with the subsequent inflammation and apoptosis cause these complications in diabetes. Garlic (G) (Allium sativum L) and Citrullus colocynthis (L.) Schrad (C) both have antidiabetic and antioxidant properties. Recently, we demonstrated their synergistic effects in alleviating reproductive complications when administered concomitantly. However, as even medicinal plants in long term usage may lead to some unwanted side effects of their own, we examined whether with half the original doses of these two medicinal plants we could achieve the desired results.

METHODS

Thirty-five male Wistar rats were divided into five groups (n = 7/group): Control, Diabetic, Diabetic + G (0.5 ml/100 g BW), Diabetic + C (5 mg/kg BW) and Diabetic + GC (0.5 ml/100 g BW of garlic and 5 mg/kg BW of C. colocynthis) groups. The experimental period was 30 days.

RESULTS

Oxidative stress, advanced glycation end products (AGEs), immunoexpression of caspase-3, and expression of mRNAs for receptor for advanced glycation end products (RAGE), NADPH oxidase-4 (NOX-4) and nuclear factor kappa B increased in testis of diabetic rats. Treatment with garlic and C. colocynthis alone showed some beneficial effects, but in the combination form the effectiveness was more profound.

CONCLUSIONS

We conclude that the combination therapy of diabetic rats with lower doses is still as efficient as higher doses; therefore, the way forward for reducing complications in long term consumption.

Long-term exposure to the mixture of phthalates induced male reproductive toxicity in rats and the alleviative effects of quercetin

Phthalates (PEs), such as di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP) could cause reproductive and developmental toxicities, while human beings are increasingly exposed to them at low-doses. Phytochemical quercetin (Que) is a flavonoid that has estrogenic effect, anti-inflammatory and anti-oxidant effects. This study was conducted to assess the alleviative effect of Que. on male reproductive toxicity induced by the mixture of three commonly used PEs (MPEs) at low-dose in rats, and explore the underlying mechanism. Male rats were treated with MPEs (16 mg/kg/day) and/or Que. (50 mg/kg/d) for 91 days. The results showed that MPEs exposure caused male reproductive injuries, such as decreased serum sex hormones levels, abnormal testicular pathological structure, increased abnormal sperm rate and changed expressions of PIWIL1 and PIWIL2. Furthermore, MPEs also changed the expression of steroidogenic proteins in steroid hormone metabolism, including StAR, CYP11A1, CYP17A1, 17β-HSD, CYP19A1. However, the alterations of these parameters were reversed by Que. MPEs caused male reproductive injuries in rats; Que. inhibited MPEs' male reproductive toxicity, which might relate to the improvement of testosterone biosynthesis.

Omega 3 fatty acid improves sexual and erectile function in BPF-treated rats by upregulating NO/cGMP signaling and steroidogenic enzymes activities

Bisphenol F (BPF) is an environmental pollutant that has been implicated in sexual dysfunction. Omega 3 fatty acid (O3FA), on the other hand, is an antioxidant with the ability to improve fertility indices. However, no study has explored the possible ameliorative effect of O3FA on BPF-induced sexual dysfunction. Thus, the effect of BPF and/or O3FA on male sexual performance was investigated. Male Wistar rats were randomized into 6 groups, corn oil-treated, O3FA low and high dose (100 and 300 mg/kg), BPF-treated, BPF + O3FA low and BPF + O3FA high dose. BPF significantly impaired male sexual competence, evidenced by a reduction in motivation to mate, prolonged mount, intromission and ejaculation latency, and post-ejaculatory index. Furthermore, a reduction in mount, intromission, and ejaculation frequency were observed. Also, BPF caused a decrease in gonadotropin releasing hormone, follicle stimulating hormone, luteinizing hormone, testosterone, nitric oxide (NO) cyclic guanosine monophosphate (cGMP), 3beta-hydroxysteroid dehydrogenase (3β-HSD), 17beta-hydroxysteroid dehydrogenase (17β-HSD), dopamine, and acetylcholine esterase. Furthermore, it was accompanied by a significant increase in prolactin and estrogen and poor pregnancy outcomes. These observed BPF-led alterations were abolished by O3FA administration. This study showed that O3FA ameliorates BPF-induced sexual dysfunction by upregulating NO/cGMP signaling and steroidogenic enzymes activities.

Effects of postnatal exposure to cadmium on male sexual incentive motivation and copulatory behavior: Estrogen and androgen receptors expression in adult brain rat

There are numerous evidence showing that cadmium (Cd) is an endocrine disruptor that exerts multiple toxic effects at different reproductive levels, including male sexual behavior (MSB). The effect of early exposure to Cd on sexual incentive motivation (SIM) and MSB in adult stage, and the immunoreactivity of receptors for hormones such as estrogens and androgens in brain regions that are relevant for the SIM and MSB display, have not been studied until now. The present study evaluated the effects of 0.5 and 1 mg/kg CdCl2 from day 1-56 of postnatal life on SIM and MSB in adults rats, as well as serum testosterone concentrations, Cd concentration in blood, testis, and brain areas, and the immunoreactivity in estrogen receptors (ER-α and -β), and androgen receptor (AR) in the olfactory bulbs (OB), medial preoptic area (mPOA), and medial amygdala (MeA). Our results showed that both doses of Cd decreased SIM and MSB, accompanied by low serum concentrations of testosterone. Also, there was a significant reduction in immunoreactivity of ER-α and AR in mPOA, and a significant reduction in AR in MeA on male rats treated with Cd 1 mg/kg. These results show that exposure to high doses of Cd in early postnatal life could alter the correct integration of hormonal signals in the brain areas that regulate and display SIM and MSB in adult male rats.

What Distinguishes Males With Sexual Dysfunction Who Present to Either Psychiatrists or Urologists?

Background Organic and psychological causes are intertwined in the etiology of sexual dysfunction (SD). Another important point, as well as the importance of etiology in the treatment of sexual dysfunctions, is understanding people's approaches to the problem. This study was planned to investigate whether there is a relationship between self-esteem and body perception levels of patients with sexual dysfunction and preferential applications to urology or psychiatry outpatient clinics. Methodology The study included 125 patients who sought treatment at urology and psychiatry outpatient clinics and were diagnosed with erectile dysfunction (ED) or premature ejaculation (PE) as a result of clinical evaluation. Sociodemographic data forms, the International Erectile Function Index (IIEF-6), the Premature Ejaculation Diagnostic Tool (PEDT), the Body Image Questionnaire (BIQ), and the Self-Esteem Rating Scale (SERS), were administered to the patients. Results When the patients were evaluated according to their complaints, there was no difference between the groups in body image or self-esteem. However, when the preferential admissions were evaluated through outpatient clinics, the self-esteem and body perception levels were high in the patients who applied primarily to the psychiatry outpatient clinic (p = 0.032, p = 0.046). Conclusion Psychological factors may affect male sexual dysfunctions in treatment admissions. It is important that andrology and psychiatry doctors work in cooperation in the treatment of sexual dysfunctions.

Managing antipsychotic-related sexual dysfunction in patients with schizophrenia

INTRODUCTION

Schizophrenia is a psychotic disorder and one of the most severe and impactful mental illnesses. Sexual dysfunction is highly prevalent in patients with schizophrenia but remains underdiagnosed and undertreated. Sexual dysfunction is frequently attributed to antipsychotics which may reduce medication adherence, but negative symptoms can also reduce sexual drive.

AREAS COVERED

This review provides an overview of the current knowledge about sexual dysfunction in patients with schizophrenia. The authors first review the literature concerning the mechanisms of sexual dysfunction and explore the impact of antipsychotics on sexual function. Finally, they present the available non-pharmacological and pharmacological treatment strategies for sexual dysfunction in patients with schizophrenia.

EXPERT OPINION

Sexual dysfunction in patients with schizophrenia is still underrated by clinicians despite having a negative impact on the quality of life and therapeutic adherence. Antipsychotic treatment is still perceived as a major cause of sexual impairment. Psychiatrists must be aware of this condition and actively question the patients. A comprehensive approach, addressing pharmacological and non-pharmacological aspects, is fundamental for managing sexual dysfunction in schizophrenia. Pharmacological strategies include (1) Serum-level adjustment of the antipsychotic dose, if possible (2) switching to a well-tolerable antipsychotic (aripiprazole, brexpiprazole) and (3) adding a coadjuvant drug (phosphodiesterase-5 inhibitors).

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

Low Exercise Tolerance as a Marker of Erectile Dysfunction and Depression among Post-Myocardial Infarction Men

Evidence has grown recently on the correlation between lifestyle and physical activity, and their impact on the functioning of the entire organism. In addition, a decrease in physical efficiency may be an indicator of the early diagnosis of systemic diseases. The aim of this study was to determine whether there is a relationship between exercise tolerance and possible erectile dysfunction or mental disorders. A cross-sectional study was conducted among 254 men in 4 cardiac rehabilitation centers in Poland using the standardized International Index of Erectile Function 5 (IIEF-5) and Beck Depression Inventory (BDI) questionnaires. Erectile dysfunction was directly proportional to the metabolic equivalent of the task (MET) variable. An increase in exercise tolerance by 1 point was associated with an increase in the IIEF-5 score by 1.62 points, indicating a reduction in the severity of erectile dysfunction. The 1-point increase in MET was associated with a 1.8-point decrease in BDI, indicating that an increase in exercise tolerance is associated with a decrease in the severity of depressive disorders. Increasing the tolerance of physical effort has a beneficial effect not only on the general well-being, but also on the sexual and mental health of men. An increase in exercise tolerance is associated with a reduction in the incidence of erectile dysfunction. On the other hand, in patients with depressive disorders, the improvement of exercise tolerance reduces the intensity of depression symptoms. Exercise tolerance can be an early and simple marker at the onset of erectile dysfunction or mood disorders.

Combined Protective Effects of Quercetin, Rutin, and Gallic Acid against Cadmium-Induced Testicular Damages in Young-Adult Rats

Cadmium (Cd) is a toxic metal that damages several tissues of animals and humans including the testis. The ameliorative effects of quercetin (QUE), rutin (RUT), and gallic acid (GAL) at 20 mg kg-1 body weight alone or in combination against testicular injury induced by Cd (24 mg kg-1 body weight) in male Wistar rats were evaluated in this study. Forty-two (42) rats were randomly grouped into six (6) groups: (1) vehicle control group, (2) Cd group, (3) RUT+Cd group, (4) GAL+Cd group, (5) QUE+Cd group, and (6) RUT+GAL+QUE+Cd group. At the end of the oral gavage of the tested chemicals, the rats were sacrificed, blood samples were collected, and testes were harvested and processed for biochemical assays. Cd exposure damaged the testis (smaller epithelium thickness and spermatogenesis index and sloughing of the epithelium); increased lipid peroxidation, glutathione S-transferase activity, and DNA fragmentation; and diminished glutathione reductase activity and serum testosterone level 40 days posttreatment. Treatment with the phenolics separately or in combination attenuated the effect of Cd on serum testosterone, glutathione reductase and glutathione S-transferase activities, lipid peroxidation, and percent fragmented DNA. The increased nitric oxide concentration in the QUE+Cd group was attenuated to control values in the combined (RUT+GAL+QUE+Cd) exposure group. Coadministration of the phenolics appears to have more substantial protective effects than their single effects against Cd-induced testicular DNA damage, glutathione S-transferase activity, and the recovery of testosterone levels and spermatogenesis index. Overall, the tested phenolics can reduce testicular damage more efficiently in their combined form than individual administration.

Synergistic properties of garlic and Citrullus colocynthis on reproductive injury caused by diabetes in male rats: Structural and molecular evidence

This study evaluates the synergistic effect of garlic and Citrullus colocynthis on diabetic reproductive damage by suppressing the AGEs/RAGE/Nox-4 signaling pathway. Thirty-five male Wistar rats were divided into five groups (n = 7/group): Control, Diabetic, Diabetic+G (Garlic, 1 mL/100 g b.w), Diabetic+C (C. colocynthis, 10 mg/kg b.w) and Diabetic+GC (Garlic, 1 mL/100 g b.w and C. colocynthis, 10 mg/kg b.w) groups. At the end of the experimental period (30 days), in diabetic rats, glucose increased, and body & testis weight, luteinizing hormone (LH) and testosterone levels, and sperm count decreased significantly and histopathological injuries were observed. In addition, they have increased testicular apoptosis and oxidative stress. Also, the mechanism based on advanced glycation end products (AGEs)/receptors for advanced glycation end products (RAGE)/NADPH oxidase-4 (Nox-4) was activated in diabetic rats. Separate consumption of garlic and C. colocynthis in Diabetic+G and Diabetic+C groups alleviated the negative adverse effect of diabetes to some extent, but when they were used in the combination form (Diabetic+GC) improvement was profound. Testis histopathology, increased body and testis weight, and enhanced capacity in protecting diabetic reproductive injury was seen. Decreases in testosterone and LH concentration and sperm count in diabetic rats were also reversed by combined administration of garlic and C. colocynthis. It regulated oxidative stress markers, meanwhile reducing caspase-3 immunoexpression. In addition, overexpression of RAGE, Nox-4 and nuclear transcription factor-κB (NF-κB) was inhibited by the combination of garlic and C. colocynthis. PRACTICAL APPLICATIONS: Diabetes mellitus is wide spread all around the world with variety of complications in body including reproductive system in which patients suffer from physical and psychological aspects. Despite many efforts in providing agents for controlling diabetes and its complications, economic conditions of some countries make it difficult for people to provide costly medicine and as a result, they have to bear the complications until they pass away. However, traditional medicine is still finding its way, especially in poor countries with emphasis on medicinal plants. There have been many studies on plants to alleviate diabetes or its side effects. But, using one plant for long term, may be not so effective. Here, we attempted to find whether two plants from two different species can show more efficacy than each one alone. We noticed garlic and Citrullus colocynthis despite having beneficial effects when used alone, they could show synergistic effects in combination.

Potential Role of Quercetin in Polycystic Ovary Syndrome and Its Complications: A Review

Polycystic ovary syndrome (PCOS) is a common multisystem disease with reproductive, metabolic and psychological abnormalities. It is characterized by a high prevalence rate in women of childbearing age and highly heterogeneous clinical manifestations, which seriously harm women’s physical and mental health. Quercetin (QUR) is a natural compound of flavonoids found in a variety of foods and medicinal plants. It can intervene with the pathologic process of PCOS from multiple targets and channels and has few adverse reactions. It is mentioned in this review that QUR can improve ovulation disorder, relieve Insulin resistance (IR), reduce androgen, regulate lipid metabolism, regulate gut microbiota and improve vascular endothelial function, which is of great significance in the treatment of PCOS.

Pharmacological action of quercetin against testicular dysfunction: A mini review

The testis is an immune-privileged organ susceptible to oxidative stress and inflammation, two major factors implicated in male infertility. A reduction in the concentration and activities of testicular function biomarkers has been shown to correlate with impaired hypothalamic-pituitary-testicular axis and oxidative stress. However, the use of natural products to ameliorate these oxidative stress-induced changes may be essential to improving male reproductive function. Quercetin possesses several pharmacological activities that may help to combat cellular reproduction-related assaults, such as altered sperm function and reproductive hormone dysfunction, and dysregulated testicular apoptosis, oxidative stress, and inflammation. Studies have shown that quercetin ameliorates testicular toxicity, largely by inhibiting the generation of reactive oxygen species, with the aid of the two antioxidant pharmacophores present in its ring structure. The radical-scavenging property of quercetin may alter signal transduction of oxidative stress-induced apoptosis, prevent inflammation, and increase sperm quality in relation to the hormonal concentration. In this review, the therapeutic potential of quercetin in mediating male reproductive health is discussed.

The consequence and mechanism of dietary flavonoids on androgen profiles and disorders amelioration

Androgen is a kind of steroid hormone that plays a vital role in reproductive system and homeostasis of the body. Disrupted androgen balance serves as the causal contributor to a series of physiological disorders and even diseases. Flavonoids, as an extremely frequent family of natural polyphenols, exist widely in plants and foods and have received great attention when considering their inevitable consumption and estrogen-like effects. Mounting evidence illustrates that flavonoids have a propensity to interfere with androgen synthesis and metabolism, and also have a designated improvement effect on androgen disorders. Therefore, flavonoids were divided into six subclasses based on the structural feature in this paper, and the literature about their effects on androgens published in the past ten years was summarized. It could be concluded that flavonoids have the potential to regulate androgen levels and biological effects, mainly by interfering with the hypothalamic-pituitary-gonadal axis, androgen synthesis and metabolism, androgen binding with its receptors and membrane receptors, and antioxidant effects. The faced challenges about androgen regulation by flavonoids masterly include target mechanism exploration, individual heterogeneity, food matrixes interaction, and lack of clinical study. This review also provides a scientific basis for nutritional intervention using flavonoids to improve androgen disorder symptoms.

Ameliorative effects of a curcumin vitamin E nanocomposite coated with olive oil against cadmium chloride-induced testicular damage

In the current study, we synthesized and prepared a curcumin and vitamin E nanocomposite coated with olive oil (CEONC). Curcumin, vitamin E, and olive oil are fundamental organic antioxidants, and forming nanoparticles from these components endows them with special characteristics. We investigated the protective effect of CEONC on reproductive toxicity induced by cadmium chloride (CdCl2 ) in male rats. Forty rats (170-180 g) were randomly assigned to four groups: Group 1 (control) received oral distilled water; Group 2 intraperitoneal injection with CEONC (30 mg/kg); Group 3 received oral CdCl2 (5 mg/kg); and Group 4 received CdCl2 (5 mg/kg) followed by CEONC (30 mg/kg) for 4 weeks. After 50 days, we terminated the experiment and assessed male reproductive hormones, sperm motility, viability and morphology, and testes histopathology and conducted a comet assay. The results revealed that co-administration of CEONC with CdCl2 exposure increased reproductive hormone levels, improved sperm motility and viability, prevented sperm morphological changes, recovered the testicular histology, and decreased DNA damage in the testicular tissue compared to rats exposed to CdCl2 alone. CEONC administration produced no adverse effects and enhanced all sperm parameters. Our findings demonstrate that CEONC is a potential treatment for preventing reproductive damage induced by cadmium exposure.

Exposure to low-dose cadmium induces testicular ferroptosis

As an environmental pollutant, cadmium (Cd) has been widely reported to induce male infertility due to its gonadotoxicity. However, the specific mechanism of Cd-induced testicular damage remains unclear. We investigated whether Cd causes testicular injury through ferroptosis. Male C57BL/6 J mice were exposed to 0, 0.5, or 5 ppm Cd via drinking water, starting in utero, and continuing through 24 weeks post-weaning. The results showed that Cd accumulated in the testes in a dose-dependent manner. Cd exposure at a concentration of 5 ppm, but not 0.5 ppm, caused a mass loss and detachment of germ cells, as well as a decreased meiotic index and testis weight. Exposure to 5 ppm Cd caused iron accumulation, increased levels of malondialdehyde (MDA) and nitro tyrosine (3-NT), and decreased expression of Nrf2, HO-1 and SOD2. We also found that exposure to 5 ppm Cd significantly decreased the expression of SLC7A11, a marker of ferroptosis in mice, along with the expression of SLC40A1 mRNA and ferritin heavy chain (FTH) protein, whereas there was no obvious change in the mRNA expression of Tfrc, ZIP8, ZIP14, and NCOA4. These findings indicate that 5 ppm Cd exposure increased testicular ferroptosis, which may be attributed to the reduction of stored iron export.

Cadmium induces testosterone synthesis disorder by testicular cell damage via TLR4/MAPK/NF-κB signaling pathway leading to reduced sexual behavior in piglets

Cadmium (Cd) is a highly toxic metal pollutant that can endanger the life and health of animals. Toll-like receptor 4 (TLR4) can result in testicular cell damage by positively regulating mitogen-activated protein kinase (MAPK)/nuclear factor-kappaB (NF-κB) signaling pathway. Meanwhile, Testosterone (T) synthesis disorder can affect sexual behavior. However, the harmful influence of Cd on animal sexual behavior during its growth and development and the role of TLR4/MAPK/NF-κB signaling pathway in testicular cell damage and testosterone production remained poorly understood. Forty-two-day-old male piglets were fed with diets that contained CdCl₂ (20 mg Cd/kg) for 40 days to explore the toxic effects of Cd on sexual behavior. The results showed that Cd activated TLR4, promoted MAPK (p-ERK, p-JNK, and p-p38)/NF-κB expression, induced apoptosis (Caspase-3, Cleaved Caspase3, Bax, Cyt-c, and Caspase-9 expression increased, but Bcl-2 expression decreased) and necroptosis (MLKL, RIPK1, and RIPK3 expression increased) in piglet testis. In addition, Cd exposure decreased mRNA expression of STAR, CYP11A1, 3β-HSD, CYP17A1, and 17β-HSD of testis and the concentrations of T and thyroid-stimulating hormone (TSH). Both the mRNA and protein expression levels of the major genes in TLR4/MAPK/NF-κB signaling pathway, apoptosis signaling pathway, and necroptosis signaling pathway increased significantly and the expression levels of testosterone decreased gradually in pig Leydig cells cultured in vitro after being treated with different concentrations of Cd. Moreover, Cd reduced sexual behavior (the parameters of sniffing, chin resting, and mounting decreased) in piglets. In conclusion, Cd induced testicular cell damage via TLR4/MAPK/NF-κB signaling pathway leading to testosterone synthesis disorder and sexual behavior reduction in piglets.

Physiological Roles of Red Carrot Methanolic Extract and Vitamin E to Abrogate Cadmium-Induced Oxidative Challenge and Apoptosis in Rat Testes: Involvement of the Bax/Bcl-2 Ratio

The precise analysis of the contents of the red carrot is still ambiguous and its role in the maintenance of male fertility needs to be further reconnoitered. Hence, this study targets the physiological impacts of either red carrot methanolic extract (RCME) or vitamin E (Vit. E), co-administrated with cadmium chloride (CdCl₂) on rat testes, specifically those concerned with apoptosis and oxidative challenge. Four groups of adult male rats (n = 12) are used; control, CdCl₂, CdCl₂ + Vit. E and CdCl₂ + RCME. LC-MS analysis of RCME reveals the presence of 20 different phytochemical compounds. Our data clarify the deleterious effects of CdCl₂ on testicular weights, semen quality, serum hormonal profile, oxidative markers and Bax/Bcl-2 ratio. Histopathological changes in testicular, prostatic and semen vesicle glandular tissues are also observed. Interestingly, our data clearly demonstrate that co-administration of either RCME or Vit. E with CdCl₂ significantly succeeded in the modulation (p < 0.05) of all of these negative effects. The most striking is that they were potent enough to modulate the Bax/Bcl-2 ratio as well as having the ability to correct the impaired semen picture, oxidant status and hormonal profile. Thus, RCME and Vit. E could be used as effective prophylactic treatments to protect the male reproductive physiology against CdCl₂ insult.

Counteracting effects of heavy metals and antioxidants on male fertility

Infertility is regarded as a global health problem affecting 8-12% of couples. Male factors are regarded as the main cause of infertility in 40% of infertile couples and contribute to this condition in combination with female factors in another 20% of cases. Abnormal sperm parameters such as oligospermia, asthenospermia, and teratozoospermia result in male factor infertility. Several studies have shown the deteriorative impact of heavy metals on sperm parameters and fertility in human subjects or animal models. Other studies have pointed to the role of antioxidants in counteracting the detrimental effects of heavy metals. In the currents study, we summarize the main outcomes of studies that assessed the counteracting impacts of heavy metal and antioxidants on male fertility. Based on the provided data from animal studies, it seems rational to administrate appropriate antioxidants in persons who suffer from abnormal sperm parameters and infertility due to exposure to toxic elements. Yet, further human studies are needed to approve the beneficial effects of these antioxidants.

Metformin mitigates impaired testicular lactate transport/utilisation and improves sexual behaviour in streptozotocin-induced diabetic rats

CONTEXT

Lactate is the preferred energy substrate for developing testicular germ cells. Diabetes is associated with impaired testicular lactate transport/utilisation, and poor sexual behaviour.

OBJECTIVE

To examine the effects of metformin on parameters involved in testicular lactate production, transport/utilisation, and sexual behaviour in diabetic state.

METHODS

Male Sprague-Dawley rats were assigned into normal control (NC), diabetic control (DC), and metformin-treated diabetic group (n = 6/group). Metformin (300 mg/kg b.w./day) was administrated orally for 4 weeks.

RESULTS

Intra-testicular glucose and lactate levels, and lactate dehydrogenase (LDH) activity increased, while the mRNA transcript levels of genes responsible for testicular glucose and lactate transport/utilisation (glucose transporter 3, monocarboxylate transporter 4 (MCT4), MCT2, and LDH type C) decreased in DC group. Furthermore, penile nitric oxide increased, while cyclic guanosine monophosphate decreased, with impaired sexual behaviour in DC group. Treatment with metformin improved these parameters.

CONCLUSIONS

Metformin increases testicular lactate transport/utilisation and improves sexual behaviour in diabetic state.

Comprehensive Review of Cadmium Toxicity Mechanisms in Male Reproduction and Therapeutic Strategies

Cadmium (Cd) has been widely studied as an environmental pollutant for many years. Numerous studies have reported that Cd exposure causes damage to the heart, liver, kidneys, and thyroid in vivo. The emerging evidence suggests that Cd exposure induces damage on male reproductive system, which is related to oxidative stress, inflammation, steroidogenesis disruption, and epigenetics. Current preclinical animal studies have confirmed a large number of proteins and intracellular signaling pathways involved in the pathological process of Cd-induced male reproductive damage and potential measures for prophylaxis and treatment, which primarily include antioxidants, anti-inflammatory agents, and essential ion supplement. However, explicit pathogenesis and effective treatments remain uncertain. This review collects data from the literatures, discusses the underlying mechanisms of Cd-induced toxicity on male reproductive function, and summarizes evidence that may provide guidance for the treatment and prevention of Cd-induced male reproductive toxicity.

Protective effect of naringenin against cadmium-induced testicular toxicity in male SD rats

This study aimed to investigate the effect of naringenin (Nar) on cadmium (Cd)-induced testicular toxicity. Twenty-four male Sprague-Dawley (SD) rats aged 5 weeks were used. Rats were administered with 0.9% NaCl (control group), CdCl₂ (2 mg/kg b.w. intraperitoneally), Nar (50 mg/kg b.w, orally), and CdCl₂ + Nar (2 mg/kg b.w intraperitoneally and 50 mg/kg b.w. orally, respectively) for 4 weeks. Results showed that body weight, relative testis weights, and sperm quality decreased in the Cd-treated group, and Cd accumulated in serum and testes. Pathological examination showed that Cd can cause testicular damage. Cd decreased the serum concentrations of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. It also decreased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Moreover, exposure to Cd resulted in decreased content of reduced glutathione (GSH) and total antioxidant capacity (T-AOC) concentrations, as well as increased malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents. Cd also provoked testis autophagy by upregulating the expression of the autophagy-related proteins P62 and LC3 II. However, the combined administration of Nar and Cd significantly attenuated the Cd-induced negative effects by increasing the body weight, relative testis weights, and sperm quality and by decreasing testicular damage. Simultaneous supplementation of Nar and Cd markedly restored the decreased levels of GnRH, FSH, LH, testosterone, GSH, and T-AOC and the activities of SOD, CAT, and GPx caused by Cd treatment. Nar further suppressed MDA and H₂O₂ production and protected the testes from Cd-induced autophagy by downregulating P62 and LC3 II expression. Therefore, Nar protected the testes from Cd-induced toxicity.

Improvement of Testicular Steroidogenesis Using Flavonoids and Isoflavonoids for Prevention of Late-Onset Male Hypogonadism

Androgen production, being important for male fertility, is mainly accomplished by the Leydig cells from the interstitial compartment of the testis. Testosterone plays a critical role in testis development, normal masculinization, and the maintenance of spermatogenesis. Within seminiferous tubules, appropriate Sertoli cell function is highly dependent on testicular androgen levels and is essential to initiate and maintain spermatogenesis. During aging, testosterone production by the testicular Leydig cells declines from the 30s in humans at a rate of 1% per year. This review outlines the recent findings regarding the use of flavonoids and isoflavonoids to improve testosterone production, contributing to normal spermatogenesis and preventing age-related degenerative diseases associated with testosterone deficiency. With the cumulation of information on the actions of different flavonoids and isoflavonoids on steroidogenesis in Leydig cells, we can now draw conclusions regarding the structure-activity relationship on androgen production. Indeed, flavonoids having a 5,7-dihydroxychromen-4-one backbone tend to increase the expression of the steroidogenic acute regulatory protein (StAR), being critical for the entry of cholesterol into the mitochondria, leading to increased testosterone production from testis Leydig cells. Therefore, flavonoids and isoflavonoids such as chrysin, apigenin, luteolin, quercetin, and daidzein may be effective in delaying the initiation of late-onset hypogonadism associated with aging in males.

Malaysian propolis and metformin mitigate subfertility in streptozotocin-induced diabetic male rats by targeting steroidogenesis, testicular lactate transport, spermatogenesis and mating behaviour

BACKGROUND

Diabetes mellitus is one of the risk factors for male subfertility/infertility. Malaysian propolis is reported to decrease hyperglycaemia in diabetic state.

OBJECTIVES

The present study investigated the protective effect of Malaysian propolis on diabetes-induced subfertility/infertility. Additionally, its combined beneficial effects with metformin were investigated.

MATERIALS AND METHODS

Forty adult male Sprague Dawley rats were randomly assigned into five groups, namely normal control, diabetic control, diabetic + Malaysian propolis (300 mg/k.g. b.w.), diabetic + metformin (300 mg/kg b.w.) and diabetic + Malaysian propolis + metformin. Diabetes was induced using a single intraperitoneal injection of streptozotocin (60 mg/kg b.w.) and treatment lasted for 4 weeks. During the 4th week, mating behavioural experiments were performed using sexually receptive female rats. Thereafter, fertility parameters were assessed in the female rats.

RESULTS

Malaysian propolis increased serum and intratesticular free testosterone levels, up-regulated the mRNA levels of AR and luteinizing hormone receptor, up-regulated the mRNA and protein levels of StAR, CYP11A1, CYP17A1, 3β-HSD and 17β-HSD in the testes of diabetic rats. Furthermore, Malaysian propolis up-regulated testicular MCT2, MCT4 and lactate dehydrogenase type C mRNA levels, in addition to improving sperm parameters (count, motility, viability and normal morphology) and decreasing sperm nDNA fragmentation in diabetic rats. Malaysian propolis improved mating behaviour by increasing penile guanosine monophosphate levels. Malaysian propolis also improved fertility outcome as seen with decreases in pre- and post-implantation losses, increases in gravid uterine weight, litter size per dam and foetal weight. Malaysian propolis's effects were comparable to metformin. However, their combination yielded better results relative to the monotherapeutic interventions.

CONCLUSION

Malaysian propolis improves fertility potential in diabetic state by targeting steroidogenesis, testicular lactate metabolism, spermatogenesis and mating behaviour, with better effects when co-administered with metformin. Therefore, Malaysian propolis shows a promising complementary effect with metformin in mitigating Diabetes mellitus-induced subfertility/infertility.

Cadmium toxicity: effects on human reproduction and fertility

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

Potential effect of advanced glycation end products (AGEs) on spermatogenesis and sperm quality in rodents

The aim of the present study was to assess whether dietary advanced glycation end products (AGEs) induce testicular dysfunction. Using a BALB/c mouse model, AGE intake and serum levels were found to increase in AGE diet-treated mice relative to the controls. Histopathological damage was detected in the testes and epididymides of the AGE diet-induced mice. The total number of epididymal sperm decreased, and increased abnormal sperm rate was found in the mice. Moreover, the mice testes showed an increased level of the receptor for AGEs (RAGE) and malondialdehyde (MDA). Using a Sprague-Dawley rat model, AGE diet-induced rats showed 3- to 4-fold higher AGE intake than the controls. In these rats, higher serum and sperm MDA levels, decreased epididymal sperm numbers, and increased abnormal sperm rates were also observed. Silymarin, a natural AGE inhibitor, was found to restore these AGE-induced phenomena. Concluding from the above findings, dietary AGEs may promote testicular dysfunction.

The cross talk of adrenal and Leydig cell steroids in Leydig cells

Glucocorticoid is secreted by adrenal cortex, which binds to intracellular glucocorticoid and mineralocorticoid receptors to regulate steroidogenesis-related gene expression and testosterone production in Leydig cells. Glucocorticoid receptor activity shows inhibitory action on Leydig cell steroidogenesis, while mineralocorticoid receptor activity shows the stimulatory action. Leydig cells contain two important glucocorticoid-metabolizing enzymes, 11β-hydroxysteroid dehydrogenase type 1 and type 2, regulating the intracellular levels of glucocorticoids by a pre-receptor mechanism. 11β-Hydroxysteroid dehydrogenase type 1 is a bidirectional enzyme, and its direction is regulated by intracellular NADP⁺/NADPH redox potential. Leydig cells contain many steroidogenic enzymes, possibly regulating NADP⁺/NADPH redox potential by coupling with 11β-hydroxysteroid dehydrogenase type 1. Here, we review the 11β-hydroxysteroid dehydrogenase regulation and possible consequences in Leydig cell biology and pathology.

Rutin alleviates cadmium-induced neurotoxicity in Wistar rats: involvement of modulation of nucleotide-degrading enzymes and monoamine oxidase

Rutin is a flavonoid commonly found in many vegetables, fruits and other plant species. Thus, this study investigated the protective role of rutin on cognitive function and impairment of ectonucleotidase, monoamine oxidase (MAO) and antioxidant enzymes activities in the cortex and hippocampus of cadmium-induced rats. Cognitive impairment was induced by an oral administration of 5 mg/kg Cadmium chloride for 14 consecutive days. Rutin was dissolved in 2% dimethyl sulfoxide (DMSO) and administered orally at the doses of 25 and 50 mg/kg for 14 days. Thereafter, animals were divided into six groups (n = 6) as follows: control, rutin 25 mg/kg, rutin 50 mg/kg, cadmium, cadmium plus rutin 25 mg/kg, cadmium plus rutin 50 mg/kg. After treatment period of 14 days, animals were sacrificed and the brain was dissected into cortex and hippocampus. Results showed that cadmium caused a significant increase in ectonucleotidases, adenosine deaminase (ADA) and MAO activities, with a concomitant decrease in thiol levels and antioxidant enzymes activities. However, treatment with rutin decreased ectonucleotidase, ADA and MAO activities in cadmium-induced rats. In addition, rutin reduced residual level of cadmium ion in the brain of cadmium-induced rats. Conclusively, present findings revealed that rutin could prevent/restored the impairment of the enzymes that regulate the purinergic and monoaminergic extracellular signaling and restore antioxidant status in cognitive impairment caused by prolonged cadmium exposure.

Mechanisms of honey on testosterone levels

Testosterone is an anabolic steroid and the principal sex hormone in males. Maintaining adequate levels of testosterone throughout the life span of male is very desirable, especially it is now well-known that low levels of testosterone is associated with various aging diseases/disorders. Therefore, still, so many research studies have focused on enhancing serum levels of testosterone in males. Here, we intended to systematically discuss and present the impact of honey on serum levels of testosterone in males. This was conducted by searching PubMed, Scopus, and Embase electronic databases for research articles from May 1993 through April 2019 using the keywords “honey” and “honeybee” versus “testosterone”. Moreover, references from relevant published articles were also reviewed and cited to frame an integral discussion, conclusion, and future research needs. In conclusion, the collective evidence, which is mainly based on in vivo system studies, reveals that oral administration of honey increases serum testosterone level in males. Mechanistically, honey may increase serum level of testosterone by increasing the production of luteinizing hormone, enhancing the viability of Leydig cells, reducing oxidative damage in Leydig cells, enhancing StAR gene expression, and inhibiting aromatase activity in the testes. However, further research studies on humans, mainly clinical trials, in this specific research approach are still needed to confirm the effect of honey on testosterone.

Protective effects of quercetin supplementation against short-term toxicity of cadmium-induced hematological impairment, hypothyroidism, and testicular disturbances in albino rats

The aim of this study was to evaluate the probable protective effect of quercetin (QUE) against cadmium (Cd)-induced sub-chronic toxicity in rats. Adult male rats were given either Cd (as cadmium chloride; 5 mg/kg) alone or in combination with QUE (50 mg/kg) daily for 4 weeks by oral gavage. At the end of the experimental period, Cd accumulation, and selected hematological, thyroid, and reproductive markers were assessed. Results revealed that Cd treatment significantly increased Cd concentrations in blood, thyroid gland, and testicular tissue of rats. Cd also caused a decline in hemoglobin content, hematocrit value, and total erythrocyte and leucocyte counts. Further, significant suppressions in the blood levels of hormones related to thyroid gland function, and male reproductive hormones (i.e., testosterone, luteinizing hormone and follicle-stimulating hormone), were observed in Cd-treated rats compared to the control. In parallel, low sperm count and sperm motility, increased sperm abnormalities, and marked pathology occurred in testis. Combination with QUE recorded amelioration of the deleterious effects of Cd, involving regulation of hematological toxicity and thyroid hormonal levels and subsequently modulation of testicular function. In conclusion, it appears that dietary QUE can rescue from Cd-induced hematological dysfunctions and testicular damage by reversing the hypothyroid state.

Testosterone in Males as Enhanced by Onion (Allium Cepa L.)

Testosterone (17β-Hydroxyandrost-4-en-3-one) is the main sex hormone in males. Maintaining and enhancing testosterone level in men is an incessant target for many researchers. Examples of such research approaches is to utilize specific types of food or dietary supplements as a safe and easily reached means. Here, specifically, since 1967 until now, many research studies have revealed the effect of onion on testosterone; however, this link has yet to be collectively reviewed or summarized. To accomplish this contribution, we searched the Scopus, Web of Science, and PubMed databases for full articles or abstracts (published in English language) from April 1967 through December 2018 using the keywords “onion” versus “testosterone”. In addition, a number of related published articles from the same databases were included to improve the integrity of the discussion, and hence the edge of the future directions. In summary, there is an evidence that onions enhance testosterone level in males. The mechanisms by which this occurs is mainly by increasing the production of luteinizing hormone, enhancing the antioxidant defense mechanism in the tests, neutralizing the damaging effects of the generated free radicals, ameliorating insulin resistance, promoting nitric oxide production, and altering the activity of adenosine 5′-monophosphate -activated protein kinase. However, this effect requires further approval in humans, mainly by conducting clinical trials.