Male Infertility: The Effect of Natural Antioxidants and Phytocompounds on Seminal Oxidative Stress

The potential significance of antioxidants in livestock reproduction: Sperm viability and cryopreservation

Male reproductive efficiency is primarily defined by the generation of high-quality and viable sperm cells in farm animals. However, the literature shows that male fertility has declined in recent years due various factors including heat stress, which causes the development of free radicals and reactive oxygen species (ROS) which damages sperm cells. This review aimed to examine the potential significance of antioxidants in increasing and preserving sperm quality and viability. Data used to produce this review paper came from recently published articles in peer reviewed journals. Google Scholar, Science Direct, Research Gate, Web of Science, and the Directory of Open Access Journals were used to access the data. Various studies have shown that antioxidants play acritical role in preserving the sperm quality and viability by protecting sperm cells from the potential damage from oxidative stress induced by the development of oxygen species imbalances. However, there is less information on the use of natural or synthetic antioxidants to preserve semen quality through in vivo procedures, despite its growing popularity and promising results. Hence, there is a need for researchers to explore more on this topic, especially in other livestock species than poultry.

Oxidative Stress Biomarkers in Male Infertility: Established Methodologies and Future Perspectives

Male fertility can be affected by oxidative stress (OS), which occurs when an imbalance between the production of reactive oxygen species (ROS) and the body's ability to neutralize them arises. OS can damage cells and influence sperm production. High levels of lipid peroxidation have been linked to reduced sperm motility and decreased fertilization ability. This literature review discusses the most commonly used biomarkers to measure sperm damage caused by ROS, such as the high level of OS in seminal plasma as an indicator of imbalance in antioxidant activity. The investigated biomarkers include 8-hydroxy-2-deoxyguanosine acid (8-OHdG), a marker of DNA damage caused by ROS, and F2 isoprostanoids (8-isoprostanes) produced by lipid peroxidation. Furthermore, this review focuses on recent methodologies including the NGS polymorphisms and differentially expressed gene (DEG) analysis, as well as the epigenetic mechanisms linked to ROS during spermatogenesis along with new methodologies developed to evaluate OS biomarkers. Finally, this review addresses a valuable insight into the mechanisms of male infertility provided by these advances and how they have led to new treatment possibilities. Overall, the use of biomarkers to evaluate OS in male infertility has supplied innovative diagnostic and therapeutic approaches, enhancing our understanding of male infertility mechanisms.

Kaempferol as an Alternative Cryosupplement for Bovine Spermatozoa: Cytoprotective and Membrane-Stabilizing Effects

Kaempferol (KAE) is a natural flavonoid with powerful reactive oxygen species (ROS) scavenging properties and beneficial effects on ex vivo sperm functionality. In this paper, we studied the ability of KAE to prevent or ameliorate structural, functional or oxidative damage to frozen-thawed bovine spermatozoa. The analysis focused on conventional sperm quality characteristics prior to or following thermoresistance tests, namely the oxidative profile of semen alongside sperm capacitation patterns, and the levels of key proteins involved in capacitation signaling. Semen samples obtained from 30 stud bulls were frozen in the presence of 12.5, 25 or 50 μM KAE and compared to native ejaculates (negative control-CtrlN) as well as semen samples cryopreserved in the absence of KAE (positive control-CtrlC). A significant post-thermoresistance test maintenance of the sperm motility (p < 0.001), membrane (p < 0.001) and acrosome integrity (p < 0.001), mitochondrial activity (p < 0.001) and DNA integrity (p < 0.001) was observed following supplementation with all KAE doses in comparison to CtrlC. Experimental groups supplemented with all KAE doses presented a significantly lower proportion of prematurely capacitated spermatozoa (p < 0.001) when compared with CtrlC. A significant decrease in the levels of the superoxide radical was recorded following administration of 12.5 (p < 0.05) and 25 μM KAE (p < 0.01). At the same time, supplementation with 25 μM KAE in the cryopreservation medium led to a significant stabilization of the activity of Mg2+-ATPase (p < 0.05) and Na+/K+-ATPase (p < 0.0001) in comparison to CtrlC. Western blot analysis revealed that supplementation with 25 μM KAE in the cryopreservation medium prevented the loss of the protein kinase A (PKA) and protein kinase C (PKC), which are intricately involved in the process of sperm activation. In conclusion, we may speculate that KAE is particularly efficient in the protection of sperm metabolism during the cryopreservation process through its ability to promote energy synthesis while quenching excessive ROS and to protect enzymes involved in the process of sperm capacitation and hyperactivation. These properties may provide supplementary protection to spermatozoa undergoing the freeze-thaw process.

Relationship between dietary glycemic index and glycemic load and sperm-quality parameters in Iranian men: a cross-sectional study

BACKGROUND

Infertility is a major clinical problem with psychological, financial and medical costs. Male infertility has recently been linked to 50% of childless couples. It is worth mentioning that diet and its components can be manipulated and applied in counseling meetings of infertile men as a modifiable factor. The goal of this study was to determine the correlation of dietary glycemic index (GI) and glycemic load (GL) with sperm-quality parameters in Iranian men.

MATERIALS AND METHODS

In this cross-sectional study which was carried from Aug to Nov 2023, after excluding smokers, 322 men who were attending the IVF clinic of Ayatollah Mousavi Hospital for seminal analysis were enrolled. Dietary intake was completed by an expert dietitian through face-to-face interviews with a validated 168-item food frequency questionnaire (FFQ). In the present study, sperm-quality parameters, including motility, concentration, normal morphology, vitality, DNA fragmentation index (DFI), and chromatin maturation of sperm, were analyzed. The relationship between dietary GI and CL and these parameters was assessed.

RESULTS

Adjusting for the baseline variables, dietary GI and GL showed positive and negative associations with sperm progressive motility, respectively (p = 0.01 and p < 0.001). Higher dietary GI was associated with lower (p = 0.03); however, a higher dietary GL was associated with higher immotile sperm (p < 0.001). A higher dietary GI was associated with a 77% higher sperm count (p = 0.003). In contrast, higher dietary GL was associated with a lower count (p < 0.001). Higher dietary GI and GL were associated with higher and lower percentages of sperm with normal morphology by 70% and 40%, respectively (p < 0.001 in both). A higher dietary GL was associated with an increase in sperm vitality and DFI of 33% and 53%, respectively (p < 0.001). Higher dietary GI showed a significant negative effect on sperm DFI (p = 0.009). Dietary GI and GL showed significant positive and negative effects on SCMA, respectively (p = 0.002 and p < 0.001).

CONCLUSION

A diet with a higher GI showed beneficial effects on more parameters of sperm; however, higher dietary GL showed deleterious effects, except sperm vitality and SCMA. More studies are needed to obtain a concise result.

The effect of alpha lipoic acid supplementation on sperm functions in idiopathic asthenozoospermic patients: a case-controlled study

Alpha-lipoic acid (ALA) is a natural short chain fatty acid containing sulfhydryl groups generated from octanoic acid and cysteine in the mitochondria, and is found in both the aqueous and lipid phases. The present study aimed to assess the efficacy of ALA supplementation in primary infertile males complaining of idiopathic asthenozoospermia. Eighty patients were randomly allocated to treatment group A (n = 40) and control group B (n = 40) groups, receiving daily doses of 600 mg (divided into two daily doses of 300 mg each) of alpha lipoic acid (ALA) or an identical placebo for 90 days. Semen analysis, anthropometric and total antioxidant capacity were analysed and compared before and after treatment. Daily supplementation with ALA improved total motility and progressive motility of the spermatozoa. In the ALA-treated group, sperm motility and progressive motility increased significantly, similarly, the mean percentage of sperm vitality demonstrated a significant increase among the ALA treated group (p < 0.001). Analysis revealed a statistically significant increase in semen volume and sperm concentration in the ALA supplemented group, while abnormal morphology decreased significantly (p < 0.001). ALA supplementation significantly improved sperm parameters and functional tests in group A patients. ALA supplementation in patients with idiopathic asthenozoospermic thus enhanced sperm quality and viability, which could therefore be considered as an adjunct therapy pending further verification of its association and mechanisms involved.

Antioxidant activity of Flemingia praecox and Mucuna pruriens and their implications for male fertility improvement

Globally, 15-24% couples are unable to conceive naturally and 50% of cases of this problem are due to infertility in males. Of this, about 50% of male infertility problems are developed due to unknown reasons called as idiopathic infertility. It is well established that, reactive oxygen species (ROS) have negative impact on male fertility and are involved in 80% of total idiopathic male infertility cases. Medicinal plants are considered as an alternative approach for mitigating the health problems. The plants with good antioxidant capacity can improve the male infertility symptoms generated by ROS. Such medicinal plants can be used to alleviate the symptoms of male infertility with their diverse phytoconstituents. Mucuna pruriens is a well-accepted herb, with its seeds being used to improve the male fertility in various ways and one of the ways is by eliminating the ROS. In our field survey, another plant, Flemingia praecox, although less known, its roots are used in all problems related to the male fertility by tribal people of the Gadchiroli district of Maharashtra, India. The study was conducted to determine in vitro antioxidant potential of F. praecox and compared the results with the well-established male fertility improving plant M. pruriens with special emphasis on medicinally important roots of F. praecox and seeds of M. pruriens. The objective of the study was investigated by studying their total phenol (TPC) and flavonoid (TFC) content, antioxidant parameters (DPPH, FRAP, ABTS, DMPD, β-carotene bleaching and TAA) and finally DNA damage protection capacity of the plant extracts was studied. The plant parts used for the medicinal purposes have been investigated along with other major parts (leaves, stem and roots of both the plants) and compared with synthetic antioxidants, BHA, BHT and ascorbic acid. Moreover, the inhibition of two male infertility enzyme markers, PDE5 and arginase by F. praecox root and M. pruriens seed extract was also studied in vitro. The results showed that F. praecox possesses higher antioxidant activity than M. pruriens in the majority of studies as observed in TFC, DPPH, TAA, ABTS and DMPD assays. However, M. pruriens seeds showed best results in TPC, FRAP and DNA damage protection assay. F. praecox root extract also gave better PDE5 inhibition value than M. pruriens seeds. This study will help to establish the authenticity of F. praecox used by tribal people and will encourage its further use in managing the male infertility problems.

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.

The role of seminal reactive oxygen species assessment in the setting of infertility and early pregnancy loss

The male contribution to a couple suffering with adverse early pregnancy outcomes is being increasingly investigated. Seminal oxidative stress is considered to cause sperm DNA damage, thus affecting the functional capacity of the sperm. Multiple lines of evidence support an association between elevated seminal reactive oxygen species (ROS) and infertility. In the setting of assisted reproduction various factors in the in vitro environment, differing from the in vivo environment, may exacerbate oxidative stress. Furthermore, seminal ROS levels have been found to be higher in the male partners of couple's affected by both spontaneous and recurrent pregnancy loss. There are several methods by which to assess ROS levels however they are costly, inconsistent and their incorporation into clinical practice is unclear. The value of ROS assessment lies in the ability to plan targeted therapies to improve pregnancy and live birth rates. As such, further robust study is required before firm conclusions can be made to inform clinical practice. We aim to review the available evidence regarding the role of seminal ROS in infertility and pregnancy loss.

The role of HIF-1α-mediated autophagy in ionizing radiation-induced testicular injury

Testis, as a key organ for maintaining male fertility, are extremely sensitive to ionizing radiation (IR). IR-induced testicular dysfunction and infertility are common adverse effects of radiation therapy in patients with pelvic cancer. To study the phenotype and mechanism of IR-induced testicular injury, the mice were irradiated with different radiation doses (0, 2 and 5 Gy) below the semi-lethal dose for one month. Our present results showed that testicular weight and the serum testosterone levels significantly decreased with the structural injury of the testis in an IR dose-dependent manner, indicating that IR caused not only the structural damage of the testis, but also the functional damage. Further analysis by TUNEL staining and Western blotting found that IR induced the apoptosis in a dose-dependent manner as indicated by increased expressions of cleaved caspase3, p53 and Bax on Day 15 after IR treatment. Combined with significantly increased oxidative stress, these results indicated that IR-induced testicular damage may be a long-term, progressively aggravated process, accompanied by apoptosis. Given the role of autophagy in apoptosis, the present study also detected and analyzed the localization and expressions of autophagy-related proteins LC-3I/II, beclin1, p62 and Atg12 in testicular cells, and found that LC-3II, beclin1 and Atg12 expressions significantly increased in the testicular cells of mice irradiated with 2 Gy and 5 Gy, while p62 expression significantly decreased with 5 Gy, implying autophagy was involved in the apoptosis of testicular cells induced by IR. Furthermore, the expressions of HIF-1α and BNIP3 were significantly enhanced in the testis cells of mice irradiated with 2 Gy and 5 Gy, suggesting the potential role of HIF-1α/BNIP3-mediated autophagy in the apoptosis of testicular cells induced by IR. Taken together, our findings demonstrated that HIF-1α/BNIP3-mediated autophagy not only plays a protective effect on the testicular cells of mice irradiated with 2 Gy, but also induces the apoptosis of the testicular cells of mice irradiated with 5 Gy, indicating the double effects on apoptosis, which will help us further understanding the molecular mechanisms of IR-induced testicular injury, and will facilitate us further studies on testicular radioprotection.

Malathion or diazinon exposure and male reproductive toxicity: a systematic review of studies performed with rodents

Malathion and diazinon are pesticides commonly used in agriculture to avoid insects that damage crops; however, they may cause impairment to the male genital system of exposed humans. The present work carried out a systematic review of the literature concerning the primary studies that assessed the reproductive effects resulting from male rats and mice exposed to malathion or diazinon. The search for articles was performed on the databases PubMed, LILACS, Scopus, and SciELO, using different combinations of the search terms "malathion," "diazinon," "mice," "rats," "male reproduction," "fertility," and "sperm," followed by the Boolean operators AND or OR. The results obtained indicate that both pesticides act as reproductive toxicants by reducing sperm quality, diminishing hormonal concentrations, inducing increased oxidative stress, and provoking histopathological damage in reproductive organs. Then, the exposure to malathion and diazinon may provoke diminished levels of testosterone by increasing acetylcholine stimulation in the testis through muscarinic receptors, thus, providing a reduction in steroidogenic activity in Leydig cells, whose effect is related to lower levels of testosterone in rodents, and consequently, it is associated with decreased fertility. Considering the toxic effects on the male genital system of rodents and the possible male reproductive toxicity in humans, it is recommended the decreased use of these pesticides and their replacement for others that show no or few toxic effects for non-target animals.

On Males, Antioxidants and Infertility (MOXI): Certitudes, Uncertainties and Trends

Male infertility (MI) involves various endogenous and exogenous facts. These include oxidative stress (OS), which is known to alter several physiological pathways and it is estimated to be present at high levels in up to 80% of infertile men. That is why since the late 20th century, the relationship between OS and MI has been widely studied. New terms have emerged, such as Male Oxidative Stress Infertility (MOSI), which is proposed as a new category to define infertile men with high OS levels. Another important term is MOXI: Male, Antioxidants, and Infertility. This term refers to the hypothesis that antioxidants could improve male fertility without the use of assisted reproductive technology. However, there are no evidence-based antioxidant treatments that directly improve seminal parameters or birth ratio. In this regard, there is controversy about their use. While certain scientists argue against their use due to the lack of results, others support this use because of their safety profile and low price. Some uncertainties related to the use of antioxidants for treating MI are their questionable efficacy or the difficulties in knowing their correct dosage. In addition, the lack of quality methods for OS detection can lead to excessive antioxidant supplementation, resulting in "reductive stress". Another important problem is that, although the inflammatory process is interdependent and closely linked to OS, it is usually ignored. To solve these uncertainties, new trends have recently emerged. These include the use of molecules with anti-inflammatory and antioxidant potential, which are also able to specifically target the reproductive tissue; as well as the use of new methods that allow for reliable quantification of OS and a quality diagnosis. This review aims to elucidate the main uncertainties about MOXI and to outline the latest trends in research to develop effective therapies with clinically relevant outcomes.

Antibacterial, antifungal, and antioxidant competence of Cardiospermum halicacabum based nanoemulsion and characterized their physicochemical properties

This research was designed to evaluate the pharmaceutical potentials of various proportions of nanoemulsions, Cardiospermum halicacabum Nanoemulsion A and Cardiospermum halicacabum Nanoemulsion B (CHE-NE-A & CHE-NE-B) prepared from the hydroalcoholic extract of Cardiospermum halicacabum through in vitro approach, and their physicochemical properties were characterized using standard scientific analytical techniques. The physicochemical and morphological properties of CHE-NE-A and CHE-NE-B were characterized by FTIR, SEM, TEM, zeta potential, and scattering light intensity analyses. The results revealed that the size, shape, and exterior conditions of nano-droplets of the CHE-NE-A nanoemulsion were suitable as a drug carrier. The reports obtained from in vitro drug releasing potential analysis support this as well. CHE-NE-A nanoemulsion constantly removes the drug from the dialysis bag than CHE-NE-B. Moreover, the CHE-NE-A showed considerable dose-dependent antioxidant activity on DPPH, ABTS, and FRAP free radicals. CHE-NE-A and CHE-NE-B were tested for their antibacterial activity with various bacterial strains. The results demonstrated that the CHE-NE-A nanoemulsion showed remarkable antibacterial activity (zone of inhibition) against test bacterial pathogens than CHE-NE-B. The antibacterial activity of CHE-NE-A at a concentration of 200 µg mL-1was in the following order, P. aeruginosa > S. aureus > S. typhimurium > S. pneumoniae > E. coli. Furthermore, CHE-NE-A has the lowest MIC values against these test bacterial pathogens than CHE-NE-B. Moreover, the CHE-NE-A also demonstrated good antifungal activity against the test fungal pathogens such as Cryptococcus neoformans, Aspergillus niger, Candida pneumonia, and Penicillium expansum than CHE-NE-B. These results strongly suggest that the CHE-NE-A nanoemulsion possesses considerable pharmaceutical potential. Interestingly, the physicochemical properties also rope that the CHE-NE-A nanoemulsion may be considered a drug carrier and useful for drug formulation.

Dietary aflatoxin B1 and antimalarial-a lumefantrine/artesunate-therapy perturbs male rat reproductive function via pro-inflammatory and oxidative mechanisms

We investigated the impact of Coartem™ (COA) and aflatoxin B1 (AFB₁) on rats' hypothalamus, epididymis, and testis. Male rats were randomly grouped (n = 5 rats) and treated: control group (corn oil), AFB₁ (70 µg/kg), COA (5 mg/kg), COA + AFB₁ (5 + 0.035 mg/kg) and COA + AFB₁ (5 + 0.07 mg/kg) for 28 days. Blood samples were collected for serum prolactin, testosterone, follicle-stimulating and luteinising hormones (FSH and LH) assay upon sacrifice. The semen, hypothalamus, epididymis, and testes were harvested for morphological, biochemical, and histopathology determination of oxidative, inflammation stress, genomic integrity, and pathological alterations. Exposure to the COA and AFB₁ caused the cauda epididymal spermatozoa to display low motility, viability, and volume, with increased abnormalities. Hormonal disruption ensued in animals exposed to COA and AFB₁ alone or together, exemplified by increased prolactin, and decreased testosterone, FSH and LH levels. Treatment-related reduction in biomarkers of testicular metabolism-acid and alkaline phosphatases, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase-were observed. Also, COA and AFB₁ treatment caused reductions in antioxidant (Glutathione and total thiols) levels and antioxidant enzyme (Catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase) activities in the examined organs. At the same time, treatment-related increases in DNA damage (p53), oxidative stress (xanthine oxidase, reactive oxygen and nitrogen species and lipid peroxidation), inflammation (nitric oxide and tumour necrosis factor-alpha), and apoptosis (caspase-9, and -3) were observed. Chronic exposure to COA and AFB1 led to oxidative stress, inflammation, and DNA damage in male rats' hypothalamic-reproductive axis, which might potentiate infertility if not contained.

Role of oxidative stress in male infertility

Abstract

Infertility affects millions of couples worldwide. Oxidative stress (OS) causes peroxidation of lipids and damage to spermatozoa, thus, reducing the quality of seminal parameters. In addition, the differences in the levels of antioxidants and reactive oxygen species (ROS) caused by intrinsic and extrinsic variables linked to lifestyle, diet, genetics, and OS also contribute to male infertility. High levels of ROS result in sperm damage of sperm parameters due to lipid peroxidation and oxidation of proteins. Other significant causes of ROS include changes in sex hormone levels, sperm DNA damage, including mutations, and immature spermatozoa. Treating the root causes of OS, by changing one's lifestyle, as well as antioxidant therapy, may be helpful strategies to fight OS-related infertility. However, the determination of male infertility induced by OS is currently a challenge in the field of reproductive health research. This review intends to describe the role of oxidative stress on male infertility and the current understanding of its management.

Lay summary

The inability to conceive affects many couples globally. Oxidative stress refers to imbalances between different oxygen species which can lead to male fertility problems by damaging sperm and semen. Oxidative stress may be caused by several factors, including diets high in fats, sugars and processed foods, lifestyle (including smoking, alcohol consumption and having a sedentary lifestyle), and genetics. Treatment that focuses on the root cause may help combat male infertility. However, there is currently no consensus on the best way to treat male fertility problems, particularly those associated with oxidative stress. This paper describes the role of oxidative stress on male infertility and discusses the current techniques employed in treating male fertility issues.

Oxidative stress, free radicals and antioxidants: potential crosstalk in the pathophysiology of human diseases

Introduction: Free radicals are reactive oxygen species that constantly circulate through the body and occur as a side effect of many reactions that take place in the human body. Under normal conditions, they are removed from the body by antioxidant processes. If these natural mechanisms are disrupted, radicals accumulate in excess and contribute to the development of many diseases. Methodology: Relevant recent information on oxidative stress, free radicals, reactive oxidative species, and natural and synthetic antioxidants was collected by researching electronic databases such as PubMed / Medline, Web of Science, and Science Direct. Results: According to the analysed studies, this comprehensive review provided a recent update on oxidative stress, free radicals and antioxidants and their impact on the pathophysiology of human diseases. Discussion: To counteract the condition of oxidative stress, synthetic antioxidants must be provided from external sources to supplement the antioxidant defense mechanism internally. Because of their therapeutic potential and natural origin, medicinal plants have been reported as the main source of natural antioxidants phytocompounds. Some non-enzymatic phytocompounds such as flavonoids, polyphenols, and glutathione, along with some vitamins have been reported to possess strong antioxidant activities in vivo and in vitro studies. Thus, the present review describes, in brief, the overview of oxidative stress-directed cellular damage and the unction of dietary antioxidants in the management of different diseases. The therapeutic limitations in correlating the antioxidant activity of foods to human health were also discussed.

Obesity-induced oxidative stress and mitochondrial dysfunction negatively affect sperm quality

Obesity is a systemic metabolic disease that can induce male infertility or subfertility through oxidative stress. The aim of this study was to determine how obesity impairs sperm mitochondrial structural integrity and function, and reduces sperm quality in both overweight/obese men and mice on a high-fat diet (HFD). Mice fed the HFD demonstrated higher body weight and increased abdominal fat content than those fed the control diet. Such effects accompanied the decline in antioxidant enzymes, such as glutathione peroxidase (GPX) and catalase and superoxide dismutase (SOD) in testicular and epidydimal tissues. Moreover, malondialdehyde (MDA) content significantly increased in sera. Mature sperm in HFD mice demonstrated higher oxidative stress, including increased mitochondrial reactive oxygen species (ROS) levels and decreased protein expression of GPX1, which may impair mitochondrial structural integrity and reduce mitochondrial membrane potential (MMP) and ATP production. Moreover, cyclic AMPK phosphorylation status increased, whereas sperm motility declined in the HFD mice. Clinical studies demonstrated that being overweight/obese reduced SOD enzyme activity in the seminal plasma and increased ROS in sperm, accompanied by lower MMP and low-quality sperm. Furthermore, ATP content in the sperm was negatively correlated with increases in the BMI of all clinical subjects. In conclusion, our results suggest that excessive fat intake had similar disruptive effects on sperm mitochondrial structure and function, as well as oxidative stress levels in humans and mice, which in turn induced lower sperm motility. This agreement strengthens the notion that fat-induced increases in ROS and impaired mitochondrial function contribute to male subfertility.

The Influence of Metabolic Factors and Diet on Fertility

Infertility is a disease globally affecting 20-30% of the reproductive age female population. However, in up to 50% on recorded cases, problems with infertility are ascribed to men; therefore, it is important to popularize healthy eating also in this group. During the last decade, it has been observed that society's lifestyle changed drastically: reduced energy expenditure in physical activity per day, increased consumption of hypercaloric and high-glycemic-index foods with high content of trans fats, and reduced consumption of dietary fiber, which negatively affects fertility. Increasing evidence points to a link between diet and fertility. It is becoming clear that well-planned nutrition can also contribute to the effectiveness of ART. The low-GI plant-based diet appears to have a positive effect, especially when it is based on Mediterranean dietary patterns: rich in antioxidants, vegetable protein, fiber, MUFA fatty acids, omega-3, vitamins, and minerals. Importantly, this diet has been shown to protect against chronic diseases associated with oxidative stress, which also translates into pregnancy success. As lifestyle and nutrition seem to be important factors affecting fertility, it is worth expanding knowledge in this regard among couples trying to conceive a child.

Effect of CoQ10 Supplement on Spermogram Parameters and Sexual Function of Infertile Men Referred to The Infertility Center of Fatemieh Hospital, Hamadan, Iran, 2019: A Randomized Controlled Trial Study

BACKGROUND

The aim of this study was to investigate the effects of the antioxidant supplement of CoQ10 and placebo in the male infertility treatment.

MATERIALS AND METHODS

The randomized controlled trial study was designed as a clinical trial. Samples in each group consisted of 30 members. The first group received 1 daily dose of 100 mg coenzyme Q10 capsules and the second group received a placebo treatment. Treatment in both groups lasted 12 weeks. Before and after the intervention of semen analysis, hormonal measurement of testosterone, prolactin, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and thyroid stimulating hormone (TSH) were done. Sexual function was assessed before and after the intervention by using the International Index of Erectile Dysfunction questionnare.

RESULTS

The mean age of participants was 34.07 (5.26) years in the CoQ10 group and 34.83 (6.22) in the placebo one. Normal volume of semen (P=0.10), viscosity (P=0.55), sperm count (P=0.28), and sperm motility (P=0.33) in the CoQ10 group increased without statistically significant differences. But the normal sperm morphology increased with statistically significant differences in the CoQ10 group (P=0.01). There was an increase in normal FSH levels and testosterone levels in the CoQ10 group compared with the placebo patients, but these differences were not statistically significant (respectively P=0.58, P=0.61). The results also revealed that the scores of erectile function (P=0.95), orgasm (P=0.86), satisfaction with sexual intercourse (P=0.61), overall satisfaction (P=0.69) and the score of the International Index of Erectile Function (IIEF, P=0.82) were greater after the intervention in the CoQ10 group than in the placebo group although the difference was not statistically significant.

CONCLUSION

The use of CoQ10 supplement can improve sperm morphology; however, in other sperm parameters and also in some hormones increased after the intervention, this was not statistically significant and therefore the result is not conclusive (registration number: IRCT20120215009014N322).

Fertility in the aging male: a systematic review

The negative effect of advanced female age on fertility and offspring health is well understood. In comparison, much less is known about the implications of male age on fertility, with many studies showing conflicting results. Nevertheless, increasing evidence suggests that advanced paternal age has negative effects on sperm parameters, reproductive success, and offspring health. Herein, we summarize the current body of knowledge on this controversial topic, with the belief that this review will serve as a resource for the clinicians providing fertility counseling to couples with older male partners.

Sperm quality and testicular histopathology of Wistar albino male rats treated with hydroethanolic extract of Cordia dichotoma fruits

CONTEXT

Cordia dichotoma Forst. (Boraginaceae) has potent pharmacological impact. Meanwhile, its effect on fertility is unclear.

OBJECTIVE

This study investigates the effect of Cordia fresh fruits hydroethanolic extract on fertility.

MATERIALS AND METHODS

120 Wistar albino male rats were divided into four groups (n = 30). The first group was negative control, and the second, third, and fourth groups received 125, 250, and 500 mg extract/kg bodyweight for 56 days. After 56 days, Cordia force-feeding stopped, and all groups were kept under laboratory conditions for another month to study the recovering effect.

RESULTS

After day 56, extract at 500 mg/kg significantly reduced sperm total count, motility%, and alive%, to 47.60 ± 2.27 × 10⁶ sperm/mL, 43.33% ± 1.49, and 63.67% ± 1.19, respectively, abnormalities% increased considerably (26.67% ± 0.54), compared to the negative control. Also, significant depletion on follicle-stimulating hormone (2.66 ± 0.21 mIU/L), luteinizing hormone (1.07 ± 0.06 mIU/L), and testosterone (2.69 ± 0.13 nmol/L) level was recorded, compared to the negative control. Cordia negative effect showed on histopathological studies of testes, prostate, and seminal vesicles. Fortunately, these adverse effects of Cordia recovered remarkably after stopping administration for one month.

CONCLUSIONS

Cordia antifertility effect may be due to its hypocholesterolemic effect, where cholesterol, the steroid cycle precursor, was significantly reduced. This study can be incorporated in clinical research after being repeated on another small experimental animal, their offspring, and one large experimental animal, then going to a clinical study that we plan to do in the future.

Cordycepin mitigates spermatogenic and redox related expression in H2O2-exposed Leydig cells and regulates testicular oxidative apoptotic signalling in aged rats

CONTEXT

Cordycepin (COR), from Cordyceps militaris L., (Cordycipitaceae), is a valuable agent with immense health benefits.

OBJECTIVE

The protective effects of COR in ageing-associated oxidative and apoptosis events in vivo and hydrogen peroxide (H₂O₂)-exposed spermatogenesis gene alterations in TM3 Leydig cells was investigated.

MATERIALS AND METHODS

Male Sprague-Dawley rats were divided into young control (YC), aged control (AC) and COR treated (COR-20) aged groups. COR-20 group received daily doses of COR (20 mg/kg) for 6 months. Cell viability and hormone levels were analysed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and enzyme immunoassay kits with COR treated at 1, 5, and 10 μg/mL. Oxidative enzymes, spermatogenic, and apoptotic expression in testis tissues were evaluated by Western blotting and real-time RT-PCR.

RESULTS

COR treatment (1, 5, and 10 μg/mL) significantly (p < 0.05 ∼ p < 0.001) inhibited the H₂O₂-induced decrease in the percentage of viable cells (from 63.27% to 71.25%, 85.67% and 93.97%, respectively), and reduced the malondialdehyde (MDA) content (from 4.28 to 3.98, 3.14 and 1.78 nM MDA/mg protein, respectively). Further, the decreased antioxidant enzymes (glutathione-S-transferase mu5, glutathione peroxidase 4 and peroxiredoxin 3), spermatogenesis-related factors (nectin-2 and inhibin-α) and testosterone levels in H₂O₂-exposed TM3 cells were significantly (p < 0.05 ∼ p < 0.001) ameliorated by COR. In aged rats, COR (20 mg/kg) restored the altered enzymatic and non-enzymatic antioxidative status and attenuated the apoptotic p53 and Bax/Bcl-2 expression significantly (p < 0.05).

CONCLUSION

COR might be developed as a potential agent against ageing-associated and oxidative stress-induced male infertility.

Contemporary Comprehensive Review on Arsenic-Induced Male Reproductive Toxicity and Mechanisms of Phytonutrient Intervention

Arsenic (As) is a poisonous metalloid that is toxic to both humans and animals. Drinking water contamination has been linked to the development of cancer (skin, lung, urinary bladder, and liver), as well as other disorders such as diabetes and cardiovascular, gastrointestinal, neurological, and developmental damage. According to epidemiological studies, As contributes to male infertility, sexual dysfunction, poor sperm quality, and developmental consequences such as low birth weight, spontaneous abortion, and small for gestational age (SGA). Arsenic exposure negatively affected male reproductive systems by lowering testicular and accessory organ weights, and sperm counts, increasing sperm abnormalities and causing apoptotic cell death in Leydig and Sertoli cells, which resulted in decreased testosterone synthesis. Furthermore, during male reproductive toxicity, several molecular signalling pathways, such as apoptosis, inflammation, and autophagy are involved. Phytonutrient intervention in arsenic-induced male reproductive toxicity in various species has received a lot of attention over the years. The current review provides an in-depth summary of the available literature on arsenic-induced male toxicity, as well as therapeutic approaches and future directions.

Antioxidant Intervention against Male Infertility: Time to Design Novel Strategies

Infertility is a highly prevalent condition, affecting 9-20% of couples worldwide. Among the identifiable causes, the male factor stands out in about half of infertile couples, representing a growing problem. Accordingly, there has been a decline in both global fertility rates and sperm counts in recent years. Remarkably, nearly 80% of cases of male infertility (MI) have no clinically identifiable aetiology. Among the mechanisms likely plausible to account for idiopathic cases, oxidative stress (OS) has currently been increasingly recognized as a key factor in MI, through phenomena such as mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation and finally, sperm apoptosis. In addition, elevated reactive oxygen species (ROS) levels in semen are associated with worse reproductive outcomes. However, despite an increasing understanding on the role of OS in the pathophysiology of MI, therapeutic interventions based on antioxidants have not yet provided a consistent benefit for MI, and there is currently no clear consensus on the optimal antioxidant constituents or regimen. Therefore, there is currently no applicable antioxidant treatment against this problem. This review presents an approach aimed at designing an antioxidant strategy based on the particular biological properties of sperm and their relationships with OS.

Age-related histopathological and biochemical testicular damages were ameliorated by vitamin C administration

INTRODUCTION AND OBJECTIVES

Aging is an irreversible process associated with decreased biological functions that can lead to the reduction of reproductive organs capacities in males and females. Paternal age is a significant predictor of offspring health and development. So, the aim of this study was to evaluate the effects of vitamin C on histopathological and biochemical testicular changes following aging process with a focus on stereological methods.

MATERIAL AND METHODS

For this study, 48 adult male NMRI mice were divided into two control and experimental groups. Mice in experimental group were supplemented with vitamin C (150mg/kg) including 24-h interval by oral gavage for 33 weeks. Same regime was performed for animals in control group except that vitamin C was replaced by water. Then, right testes were extracted for stereological and left testes were used for molecular analyses on weeks 8, 12, and 33.

RESULTS

Our findings showed low semen quality, decreased level of serum Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), and testosterone along with increased reactive oxygen species (ROS) production and higher apoptotic gene expression following aging. Stereological studies showed that the volume of testes, the length of seminiferous tubules, and the number of spermatogenic and none-spermatogenic cells decreased significantly during aging. Also, vitamin C consumption for 33 weeks significantly improved biochemical and histological indices. The impact of aging on male reproduction seems to be inevitable worldwide. Therefore, the use of protective and preventive remedies conserving male fecundity is very important and based on our results, vitamin C is a beneficial candidate for improving age-related testicular changes due to aging process.

Phthalate plasticizer decreases the prion-like protein doppel essential for structural integrity and function of spermatozoa

Di-n-butyl phthalate (DBP), a well-known endocrine disruptor, causes male reproductive dysfunction. To understand the underlying mechanisms, we performed histological, endocrinological, and biochemical analyses and assessed the expression of genes involved in spermatogenesis and sperm function according to OECD test guideline 407. Following 28 days of administration of the lowest observed adverse effect level dose of DBP to mice, no significant changes in body weight, testis and epididymis weights and histology, serum testosterone level, or testicular daily sperm production were found. Nonetheless, the motility of the epididymal sperm of the DBP group was significantly decreased together with an increase in the incidence of bent tails and abnormal heads. In the testes of the DBP group, lipid peroxidation (LPO) level was significantly increased and testicular Bcl-2 mRNA level was significantly decreased together with an increase in the Bax/Bcl-2 mRNA ratio. In the testes of the DBP group, levels of Prnd mRNA and protein and Pou4f1 mRNA, an activator of the Prnd promotor, were significantly decreased. Of note, prion-like protein doppel (PRND) was significantly decreased together with decreased PRND immunoreactivity in the head, midpiece, and tail of sperm. In the testes of the DBP group, levels of Sox9, Sgp1, and Sgp2 mRNA, which are functional Sertoli cell markers, were significantly decreased. Level of Amh mRNA, a Sertoli cell immaturity marker, was significantly increased together with that of Inha mRNA, suggesting deregulation of the brain-gonadal axis. Together, our findings suggest that DBP at present dosage may potentiate LPO generation and Sertoli cell immaturity via downregulation of Sox9 and disruption of the Pou4f1-Prnd gene network in post-meiotic germ cells without visible changes in spermatogenesis or testosterone level. This may result in structural and functional abnormalities in spermatozoa. Additionally, our findings suggest that assessment of the male reproductive toxicity of phthalate ester plasticizers based on conventional OECD test guidelines should be reconsidered.

Ameliorative effect of methanolic extract of Tribulus terrestris L. on nicotine and lead-induced degeneration of sperm quality in male rats

ETHNOPHARMACOLOGICAL RELEVANCE

The use of herbal and medicinal plants to treat male infertility is well known in history. Tribulus terrestris L. (TT) belongs to the Zygophyllaceae family and it is used in folk medicine to vitalize and also improve both physical performance and sexual function in men in addition to the protective effect of the gross saponins of TT against ischemic stroke and its clinical anti-inflammatory property.

AIM OF THE STUDY

This study aimed to investigate the effects of methanol extract of T. terrestris on nicotine hydrogen tartrate and lead-induced degeneration of sperm quality in male rats and to identify the volatile bioactive non-polar compounds thought to be responsible for its activity using gas chromatography-mass spectrometry (GC-MS).

MATERIALS AND METHODS

The effect of T. terrestris on nicotine hydrogen tartrate and lead-induced infertility was evaluated in male rats. Fifty-four mature male albino rats weighing 220-250 g body weight were used. The rats were randomly divided into 9 equal groups (n = 6). Infertility was induced by administering nicotine hydrogen tartrate (0.50 mg/kg) through peritoneal injection (i.p.) or lead acetate (1.5 g/L) orally with drinking water for sixty days. Two doses (50 and 100 mg/kg body weight of the animal) of T. terrestris were also used. At the end of the experimental period, the rats were anesthetized and sacrificed. Blood samples were collected. Hormonal analyses were carried out on the serum. The testicle, epididymis, and accessory sex organs (seminal vesical and prostates) were removed for histopathological analysis. Gas chromatography-mass spectrometry (GC-MS) analysis of the methanol extract was also carried out to identify major volatile compounds in T. terrestris methanol extract.

RESULTS

Nicotine and lead toxicity caused a significant (p < 0.05) decrease in the number of sperm, motility, and an increase in the sperm abnormalities such as the reduction in weight and size of sexual organs (testis, epididymis, and accessory sex glands), reduction of diameter and length of seminiferous tubules. The administration of T. terrestris methanol extract, however, improved the semen quantity and quality, sexual organ weights, and fertility of male rats and, thus, ameliorated the adverse effects of nicotine and lead. Ten major compounds were found from the GC-MS analysis of the extract of T. terrestris methanol extract.

CONCLUSION

Findings showed that T. terrestris plant methanolic extracts ameliorated nicotine hydrogen tartrate and lead-induced degeneration of sperm quality in male rats. The GC-MS analysis of the T. terrestris plant methanolic extracts revealed the presence of several important bioactive compounds which were thought to be responsible for the ameliorative effect. Further isolation and evaluation of the individual components would provide relevant lead to finding new drugs.

Experimental validation and molecular docking to explore the active components of cannabis in testicular function and sperm quality modulations in rats

Background

Data available support that ninety percent of male infertility cases are due to low sperm counts. There is a scarcity of data on the medicinal effects of cannabis on fertility. This study evaluated testicular function and sperm quality modulation with cannabis in rats.

Methodology

Twenty-five male Wistar rats were randomly grouped into five: A, B, C, and D, each group have 5 rats. A (control): 0.2 ml 2% DMSO, B (vitamin C): 90 mg/kg body weight, C, D, and E were administered: 5 mg/kg, 10 mg/kg and 20 mg/kg body weight of ethanolic leaf extract of cannabis (ELEC) respectively. The rats were sacrificed 24 h after the last day of the 60 day oral administrations. Flavonoids were the predominant phytochemical present in the extract while quercetin, kemferol, silyman and gallic acid were identified.

Results

The results showed a significant improvement (p < 0.05) in sperm quality and a significant increase in the concentrations of follicle-stimulating hormone, luteinizing hormone, triglycerides, cholesterol, and total protein determination compared to the normal control. Similarly, there was a significant increase (p < 0.05) in the activities of acid phosphatase, alkaline phosphatase, and superoxide dismutase compared to the normal control. RAC-alpha serine/threonine-protein kinase (AKT1)-silymarin complexes (-8.30 kcal/mol) and androgen receptor (AR)-quercetin complexes (9.20 kcal/mol) had the highest affinity.

Conclusion

The antioxidant effects of the flavonoids in the ethanolic extract of cannabis may have protected testicular and sperm cells from oxidative damage. Biochemical processes and histopathological morphology were preserved by cannabis. The docking prediction suggests that the bioactive principle of cannabis may activate the androgenic receptors. The androgenic receptor modulation may be attributed to silymarin and quercetin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03704-z.

Chlorella vulgaris ameliorates testicular toxicity induced by carbon tetrachloride in male rats via modulating oxidative stress

This study was aimed to evaluate the protective effects of Chlorella Vulgaris (CVE) (50 and 100 mg/kg doses) on sperm DNA fragmentation, testis oxidative stress in Carbon tetrachloride (CCL4)-exposed rats. Thirty healthy male Wistar rats were divided into five groups (n = 6): Control; CCl4; CVE; CCl4 + CVE50; CCl4 + CVE100. At the end of the experiment, the testicular oxidative stress parameters were estimated. The Chromomycin A3 (CMA3) and Acridine orange (AO) staining were performed to examine the sperm DNA fragmentation status. CCl4 treatment showed a significant decrease in antioxidant markers and sperm count, viability, normal morphology and motility as well as significantly increased the testicular oxidative stress markers, and the percentage of CMA3 and AO positive sperms in normal rats (p < 0.05). While CVE supplementation has revealed a significant decrease in the percentage of CMA3 and AO positive sperms as well as testicular oxidative stress markers and considerably improved the testis antioxidant status (p < 0.05). CVE has also increased the number of sperms with forwarding movement, normal morphology and viability (p < 0.05). Taken together, our analyses suggest that CVE may play a critical role in attenuating the CCl4-induced oxidative stress in the testis, thereby protecting the sperm membrane and DNA against oxidative damage.

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.

The relationship between reactive oxygen species, DNA fragmentation, and sperm parameters in human sperm using simplified sucrose vitrification with or without triple antioxidant supplementation

Objective

This study examined whether the addition of triple antioxidants (3A)—10 µM acetyl-L-carnitine, 10 µM N-acetyl-L-cysteine, and 5 µM α-lipoic acid—in freezing-thawing medium during human sperm cryopreservation using the sucrose vitrification (SuV) and liquid nitrogen vapor (Vapor) techniques could improve post-thaw survival of spermatozoa.

Methods

We analyzed 30 samples from healthy human sperm donors. Each sample was allocated into one of five groups: fresh control, SuV, SuV+3A, Vapor, and Vapor+3A. The sperm motility, morphology, viability, intracellular and extracellular reactive oxygen species (ROS) levels, and sperm DNA fragmentation (SDF) were evaluated.

Results

The cryopreserved spermatozoa had significantly reduced percentages of motility (p<0.05) and viability (p<0.05). Antioxidant supplementation non-significantly improved these parameters (p>0.05). No significant differences were found in sperm morphology between the fresh and frozen-thawed groups (p>0.05). After freezing, the extracellular ROS levels in the frozen-thawed groups were significantly higher (p<0.05) than in the fresh group. However, we did not find any differences in intracellular ROS parameters among these groups (p>0.05). The SDF was higher in the SuV and Vapor groups than in the fresh group, but without statistical significance (p=0.075 and p=0.077, respectively).

Conclusion

Cryopreservation had detrimental effects on sperm motility, viability, and extracellular ROS levels, without changing the morphology or intracellular ROS levels. Antioxidant supplementation was slightly effective in preventing SDF in frozen-thawed spermatozoa.

Distinctive features of the hypothalamic-pituitary-gonadal axis and the level of dopamine in men of the European and Asian North

In recent years, there has been a decrease in reproductive potential, especially among residents of the Arctic territories, having the greatest stress from various body systems, including the state of the hormonal regulation of the male reproductive system. The study of the dopamine levels and the content of sex hormones in the male population of various Arctic regions is relevant due to the increased stress on the part of the dopaminergic system and the hypothalamic-pituitary-gonadal axis in residents of the Northern regions, as well as the lack of information about their interaction among the apparently healthy population. The aim of the investigation is to study the possible effect of various plasma concentrations of the dopamine on the content of sex hormones and sex-steroid-binding β-globulin (SHBG) in apparently healthy men in the Arctic zone of the Russian Federation, taking into account the territory of residence. There were examined 181 men aged 22-60 years, living in the territories of the European and Asian North. The levels of sex hormones, SHBG, and dopamine were determined by the enzyme-linked immunosorbent assay. The inhabitants of the Asian North in comparison with the men of the European North have higher levels of dopamine, luteinizing hormone, progesterone, prolactin, estradiol and SHBG with decreased serum levels of free fractions of testosterone. Reference levels of dopamine in men from the European North are combined with the stimulatory effect of dopamine on LH levels, which may indicate an increase steroidogenesis. The high levels of dopamine in men from the Asian North are combined with increased level of estradiol, which may be related to the effect of dopamine on testosterone aromatization. The separate region with its ecological differences is characterized by the presence of features of compensatory-adaptive reactions of an organism in male representatives on the part of the dopaminergic system and the hypothalamic-pituitary-gonadal axis. The identified features can help in carrying out preventive measures aimed at preserving the male reproductive potential of the inhabitants of the Arctic territories.

In vitro effects of aqueous extract of unfermented rooibos on human spermatozoa

The inability to conceive is a baleful experience for thousands of couples worldwide. Among different well‐known reproductive techniques, medicinal plants have been utilized to treat male infertility. Medicinal plants, provide a therapeutic alternative, which is available and affordable for infertile couples. We investigated the direct effect of unfermented rooibos aqueous extract on human spermatozoa. Semen samples (n = 50) collected from donors and patients consulting for fertility were reassigned as normal (n = 22) and abnormal (n = 28) samples based on the outcome of the baseline semen analysis, using the World Health Organization (WHO) cut off value. Semen samples were allowed to liquefy and subsequently washed with human tubular fluid in bovine serum albumin medium. The samples were then treated with aqueous extracts of unfermented rooibos (0, 0.15, 1.5, 15, 150 μg/ml) at 37°C for 1 h and assessed thereafter. Sperm motility, vitality, DNA fragmentation, intracellular reactive oxygen species and mitochondrial membrane potential in both groups remained unchanged (p > 0.05). However, aqueous extract of unfermented rooibos (only at 1.5 μg/ml) significantly increased capacitation and acrosome reaction in the abnormal sample group (p > 0.05). Unfermented rooibos aqueous extract had no deleterious impact on human spermatozoa's function and might be attributed to its antioxidant properties.

Enzymatic Antioxidant Defense and Polymorphic Changes in Male Infertility

The intensification of oxidative stress and destabilization of the antioxidative defenses of an organism is a consequence of many environmental factors. We considered aspects conditioning male reproductive potential and the functionality of enzymatic antioxidative mechanisms, i.e., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR), and their correlations with Li, Be, B, Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Ag, Cd, Sn, Sb, Ba, Hg, Tl, Pb, and malondialdehyde (MDA), as well as genetic polymorphism IL-4v.C589T (rs2243250) in men with infertility (n = 76). A healthy normozoospermic control (n = 87) was also used. We assessed the impact of negative changes driven by oxidative stress on enzymatic antioxidative mechanisms as well as the role of MDA in the overall process. On this basis, we infer connections between disturbances in enzymatic antioxidative defense and reproductive potential. Based on a molecular analysis of the polymorphism of gene IL-4v.C589T (rs2243250) (chromosome 5) (PCR-RFLP), we considered the relationships among particular genotypes with the possibility of occurrence of male infertility. Concentrations of chemical elements were measured in the blood. The activity of antioxidants and MDA levels were measured in serum. In the infertile group, higher GPx activity was noted (6.56 nmoL·min-1·mL-1, control: 4.31 nmoL·min-1·mL-1; p = 0.004), while GR achieved a greater level in the control (17.74 nmoL·min-1·mL-1, infertile: 15.97 nmoL·min-1·mL-1, p = 0.043), which implies diversified efficiency of the first and second lines of defense. The polymorphism of IL-4v.C589T (rs2243250) was not directly connected with infertility because there were not any differences in the frequency of genotypes between the infertile and control group (p = 0.578). An analysis of genotypes CC and TT (polymorphism IL-4v.C589T (rs2243250)) indicated numerous correlations between antioxidants, chemical elements and MDA. Therefore, chemical economy, antioxidative defense and genetic conditions are connected and jointly shape male reproductive potential. Chemical elements influence antioxidative defense and male fertility; the most important modulators appeared to be Na, Ba, Al and B. The polymorphism of gene IL-4v.C589T (rs2243250) has a limited influence on antioxidative defense and the metabolism of chemical elements.

Clinical Application of Bioextracts in Supporting the Reproductive System of Animals and Humans: Potential and Limitations

There is an increasing demand of spices and herbs in developing countries due to the beneficial effects of plants and herbal preparations as medicines. The basic technological process of obtaining extracts from natural raw materials is extraction, consisting in etching with solvents. Plant extracts are extremely complex, multicomponent mixtures obtained from flowers, fruits, leaves, stems, twigs, or seeds of various plant materials. They are a rich source of polyphenols, flavonoids, phytosterols, carotenoids, and vitamins. The search for alternative methods of treatment is increasingly replacing the scientists' excessive focus on the healing properties of bioextracts. Recent research offers great hope for the development of alternative methods to improve the reproductive system. The use of animal models in experimental research has increased knowledge regarding the beneficial effects of bioextracts on both male and female reproductive systems and reproductive cells. Demonstrating the positive effect of plant extracts creates new opportunities for the use of biowaste, which is a by-product in various production sectors. The aim of this review is to present the functional properties of extracts of natural origin, a cross section of modern methods of their preparation, and a discussion of the possibilities of their use in the auxiliary reproductive system.

Zingerone attenuates zearalenone-induced steroidogenesis impairment and apoptosis in TM3 Leydig cell line

Zingerone¹ (Zing) is one of the bioactive compounds of ginger rhizome (Zingiber officinale), whose beneficial effects have been reported previously on reproductive organ complications. The current study purposed to survey probable protective impacts of Zing against Zearalenone (ZEA)-induced changes in the TM3 Leydig cell line. Exposure of TM3 cells to ZEA (25 μM) attenuates the levels of testosterone and steroidogenesis-related genes, which was reversed by 25 μM of Zing. ZEA also induced ROS generation and apoptosis in TM3 cells. Zing treatment improved the stress oxidative and apoptosis-related changes induced by ZEA in TM3 cells by modulating autophagy-related proteins and activating PI3K-AKT-mTOR and Nrf2 pathways. The findings of this study represented a theoretical basis for Zing's protective actions against ZEA toxic effects on TM3 cells.

Dietary quercetin and vitamin E supplementation modulates the reproductive performance and antioxidant capacity of aged male breeder chickens

Aged male chickens experience rapid declines in spermatogenesis, antioxidant capacity, immunity, and hormone synthesis. Vitamin E plays a significant role in reproduction, nervous system function, and disease resistance in animals. Quercetin also exerts many biological effects, such as antioxidant ability, immunostimulation, and protection of spermatozoal plasma membranes. This study evaluated the effects of combining dietary quercetin (Q) and vitamin E (VE) on sperm quality, antioxidant capacity, immunity, and expression of genes related to spermatogenesis, immunity, apoptosis, and inflammation in aged male chickens. A total of 120 Tianfu breeder male chickens (65 wk old) were randomly allotted to 4 treatments with 3 replicates (10 birds each). The birds were fed diets containing Q (0.4g/kg), VE (0.2g/kg), Q+VE (0.4g/kg + 0.2g/kg), and a basal diet for 11 wk. At the end of the experimental period, blood, semen, liver, testes, and spleen samples were collected from 2 birds per replicate. Serum hormones, antioxidant parameters, cytokines, and immunoglobulins were evaluated; and the mRNA expression of genes related to spermatogenesis, apoptosis, and inflammation are determined in the testes and liver tissues.

The results showed that the combination quercetin and vitamin E significantly promoted the sperm count and motility, as well as elevated the levels of testosterone, follicle-stimulating hormone, and luteinizing hormone, antioxidant enzymes (Superoxide dismutase, Glutathione, and Total antioxidant capacity), and serum immunoglobulins (IgA and IgM) in the aged male chickens; also Q+VE showed protective effects on the liver against injury. In addition, Q+VE significantly increased the expression of genes related to spermatogenesis (AR, pgk2, Cyclin A1, and Cyclin A2), immunity (IFN-γ and IL-2), and anti-inflammatory cytokines (IL-10) (P < 0.05), whereas the expression of proinflammatory cytokines (IL-1β and IL-6) was decreased (P < 0.05). Taken together, these data indicate that the combination of quercetin and vitamin E improved reproductive characteristics such as spermatogenesis, sperm quality, and hormone regulation, as well as promoted antioxidant defense, hepatoprotective capacity, and immune response in aged male chickens without any detrimental effects.

Naturally Occurring Antioxidant Therapy in Alzheimer’s Disease

It is estimated that the prevalence rate of Alzheimer’s disease (AD) will double by the year 2040. Although currently available treatments help with symptom management, they do not prevent, delay the progression of, or cure the disease. Interestingly, a shared characteristic of AD and other neurodegenerative diseases and disorders is oxidative stress. Despite profound evidence supporting the role of oxidative stress in the pathogenesis and progression of AD, none of the currently available treatment options address oxidative stress. Recently, attention has been placed on the use of antioxidants to mitigate the effects of oxidative stress in the central nervous system. In preclinical studies utilizing cellular and animal models, natural antioxidants showed therapeutic promise when administered alone or in combination with other compounds. More recently, the concept of combination antioxidant therapy has been explored as a novel approach to preventing and treating neurodegenerative conditions that present with oxidative stress as a contributing factor. In this review, the relationship between oxidative stress and AD pathology and the neuroprotective role of natural antioxidants from natural sources are discussed. Additionally, the therapeutic potential of natural antioxidants as preventatives and/or treatment for AD is examined, with special attention paid to natural antioxidant combinations and conjugates that are currently being investigated in human clinical trials.

Zinc transporter ZIP12 maintains zinc homeostasis and protects spermatogonia from oxidative stress during spermatogenesis

BACKGROUND

Overwhelming evidences suggest oxidative stress is a major cause of sperm dysfunction and male infertility. Zinc is an important non-enzymatic antioxidant with a wide range of biological functions and plays a significant role in preserving male fertility. Notably, zinc trafficking through the cellular and intracellular membrane is mediated by specific families of zinc transporters, i.e., SLC39s/ZIPs and SLC30s/ZnTs. However, their expression and function were rarely evaluated in the male germ cells. The aim of this study is to determine and characterize the crucial zinc transporter responsible for the maintenance of spermatogenesis.

METHODS

The expression patterns of all 14 ZIP members were characterized in the mouse testis. qRT-PCR, immunoblot and immunohistochemistry analyses evaluated the ZIP12 gene and protein expression levels. The role of ZIP12 expression was evaluated in suppressing the sperm quality induced by exposure to an oxidative stress in a spermatogonia C18-4 cell line. Zip12 RNAi transfection was performed to determine if its downregulation altered cell viability and apoptosis in this cell line. An obese mouse model fed a high-fat-diet was employed to determine if there is a correlation between changes in the ZIP12 expression level and sperm quality.

RESULTS

The ZIP12 mRNA and protein expression levels were higher than those of other ZIP family members in both the mouse testis and other tissues. Importantly, the ZIP12 expression levels were very significantly higher in both mice and human spermatogonia and spermatozoa. Moreover, the testicular ZIP12 expression levels significantly decreased in obese mice, which was associated with reduced sperm zinc content, excessive sperm ROS generation, poor sperm quality and male subfertility. Similarly, exposure to an oxidative stress induced significant declines in the ZIP12 expression level in C18-4 cells. Knockdown of ZIP12 expression mediated by transfection of a ZIP12 siRNA reduced both the zinc content and viability whereas apoptotic activity increased in the C18-4 cell line.

CONCLUSIONS

The testicular zinc transporter ZIP12 expression levels especially in spermatogonia and spermatozoa are higher than in other tissues. ZIP12 may play a key role in maintaining intracellular zinc content at levels that reduce the inhibitory effects of rises in oxidative stress on spermatogonia and spermatozoa viability during spermatogenesis which help counteract declines in male fertility.

Opuntia genus in Human Health: A Comprehensive Summary on Its Pharmacological, Therapeutic and Preventive Properties. Part 1

Opuntia spp. is a diverse and widely distributed genus in Africa, Asia, Australia, and America. Mexico has the largest number of wild species; mainly O. streptacantha, O. hyptiacantha, O. albicarpa, O. megacantha and O. ficus-indica. The latter being the most cultivated and domesticated species. Throughout history, plants and their phytochemicals have played an important role in health care and Opuntia spp. has shown a high nutritional, medicinal, pharmaceutical, and economic impacts. Its main bioactive compounds include pigments (carotenoids, betalains and betacyanins), vitamins, flavonoids (isorhamnetin, kaempferol, quercetin) and phenolic compounds. Together, they favor the different plant parts and are considered phytochemically important and associated with control, progression and prevention of some chronic and infectious diseases. This first review (Part 1), compiles information from published research (in vitro, in vivo, and clinical studies) on its preventive effects against atherosclerotic cardiovascular diseases, diabetes and obesity, hepatoprotection, effects on human infertility and chemopreventive and/or antigenotoxic capacity. The aim is to provide scientific evidences of its beneficial properties and to encourage health professionals and researchers to expand studies on the pharmacological and therapeutic effects of Opuntia spp.

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

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

The Relationship between Plant-Based Diet Index and Semen Parameters of Men with Infertility: A Cross-Sectional Study

BACKGROUND

Infertility is a major clinical problem that affects people psychologically and medically. For the past 40 years, studies have linked nearly 50% of childlessness to male infertility. It is worth noting that unlike other factors contributing to infertility, diet is a tunable factor and can be applied in counseling infertile men. The goal of this study was to determine the relationship between plant diet index (PDI) and semen parameters in Iranian infertile men.

MATERIALS AND METHODS

In this cross-sectional study, dietary intake was determined by a valid 168-item questionnaire (FFQ). In this study, four dependent semen parameters, including total sperm motility (TSM), sperm concentration (SC), normal sperm morphology (NSM), and semen volume (SV) were measured.

RESULTS

Results of this study stated that greater adherence to the healthful plant-based diet index (hPDI), can significantly increase sperm density and motility in men, as well as greater adherence to the PDI dietary pattern is related to a lower risk of sperm volume deficiency, and ultimately more adherence to the unhealthful plant-based diet index (uPDI), can reduce the risk of sperm motility.

CONCLUSION

In this study, for the first time, the relationship between PDI, hPDI, uPDI and male infertility was evaluated. Altogether, this study demonstrated that nutrition has an impact on semen quality and fertility of men.

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.

Oxidative Stress and Male Infertility: Role of Herbal Drugs

Infertility is a universal health problem affecting 15% of couples, out of which 20-30% cases are due to male infertility. The leading causes of male infertility include hormonal defects, physical reasons, sexual problems, hazardous environment, stressful lifestyle, genetic factors, epigenetic factors, and oxidative stress. Various physiological functions involve reactive oxygen species (ROS) and nitrogen species at appropriate levels for proper smooth functioning. ROS control critical reproductive processes such as capacitation, acrosomal reaction, hyperactivation, egg penetration, and sperm head decondensation. The excessive free radicals or imbalance between ROS and endogenous antioxidant enzymes damages sperm membrane by inducing lipid peroxidation causing mitochondrial dysfunction and DNA damage that eventually lead to male infertility. Numerous synthetic products are available in the market to treat infertility problems, largely ending in side effects and repressing symptoms. Ayurveda contains a particular group of Rasayana herbs, called vajikarana, that deals with nourishment and stimulation of sexual tissues, improves male reproductive vitality, and deals with oxidative stress via antioxidant mechanism. The present study aims to describe oxidative stress and the role of herbal drugs in treating male infertility.

Toxicity of Antioxidant Supplements in Patients with Male Factor Infertility: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Treating oxidative stress through antioxidant therapy has been considered an appealing strategy in the management of male infertility. However, evidence regarding the toxicity of antioxidant therapy is controversial. We summarized the available clinical evidence on the toxicity associated with the use of antioxidants in infertile males. A systematic review was performed in March 2021. We included randomized controlled trials evaluating the incidence of adverse events in male patients with infertility receiving antioxidant therapy. Thirteen studies involving 1999 male patients were identified. Antioxidant supplementation in patients with male factor infertility was associated with a statistically significantly increased risk of nausea (Odds Ratio: 2.16, 95% Confidence Interval: 1.05–4.43, p = 0.036), headache (Odds Ratio: 3.05, 95% Confidence Interval: 1.59– 5.85 p = 0.001), and dyspepsia (Odds Ratio: 4.12, 95% Confidence Interval: 1.43–11.85, p = 0.009) compared to a placebo. Treatment discontinuation due to adverse events was not significantly higher in patients taking antioxidants compared to a placebo (Odds Ratio: 2.29, 95% Confidence Interval: 0.76–6.88, p = 0.139). When antioxidant supplementation is considered, a more accurate risk/benefit analysis is warranted.

Glyphaeaside C- enriched extract of Glyphaea brevis restored the antioxidant and reproductive integrity of 1,4-Dinitrobenzene-intoxicated rats

This study assessed the fertility potential of methanol leaf extract of Glyphaea brevis (MGB) in rats exposed to 1,4-Dinitrobenzene (DNB), an environmental reprotoxicant. Male Wistar rats were orally exposed to 50 mg/kg DNB and administered 750 mg/kg MGB, 1500 mg/kg MGB or 300 mg/kg vitamin E for 21 days after 48 h of DNB exposure. Determination of serum reproductive hormone levels by enzyme-linked immunosorbent assays, evaluation of hematologic profile, computer-assisted sperm analyses (CASA) of sperm kinematics and morphology, assessment of testicular and spermatozoan antioxidant systems, and histopathological evaluation of reproductive tissues were performed. HPLC-DAD analysis identify Glyphaeaside C as the major component of the extract. In rats toxified with 50 mg/kg DNB, testicular and epididymal weights, serum levels of luteinizing hormone, testosterone and follicle-stimulating hormone, and packed cell volume, haemoglobin concentration, and white blood cell counts were decreased. There was altered sperm kinematics which reflected in increased sperm abnormalities. Treatment with the Glyphaeaside C -enriched MGB counteracted all DNB-induced changes and corrected DNB-induced aberrations in kinematic endpoints. Also, testicular and epididymal antioxidant systems were disrupted and there was damage to tissue histoarchitecture. Furthermore, our molecular docking study revealed that Glyphaeaside-C exhibited high binding affinities to the binding pocket of some free radical generating enzymes. Conclusively, the results indicated that Glyphaeaside C-enriched extract of Glyphaea brevis leaf enhanced the quality of semen and improved the functional capabilities of spermatozoa following exposure of rats to DNB which could translate to enhanced fertility.

Lycopene protects sperm from oxidative stress in the experimental varicocele model

Oxidative stress (OS) is an important parameter in the evaluation of infertility caused by varicocele. Antioxidants are the most commonly prescribed drugs in these patients. Lycopene molecule, as the powerful antioxidant in the carotenoid family, has beneficial effects on improving fertility in males. Therefore, we investigated the effects of lycopene on induced OS by varicocele in an animal model. Forty-five adult male Wistar rats were divided into two groups: control (n = 12) and varicocele (n = 33). Two months after induced varicocele, five rats in each group were sacrificed randomly and induced varicocele was investigated. Remained rats were divided into five groups (n = 7), including the control (I), varicocele (II), varicocele reserving solvent (III), varicocele reserving lycopene 4 mg/kg (IV), and 10 mg/kg (V) for two months. At the end of the experiment, intracellular reactive oxygen species (ROS), malondialdehyde (MDA), total antioxidant capacity (TAC), %DNA damage, and antioxidant enzymatic levels were measured. The results indicated that there were significant increases in the levels of ROS, MDA, DNA damage, superoxide dismutase (SOD), sperm concentration, and motility in the varicocele groups compared with the control group. In the lycopene group (10 mg/kg), sperm concentration, the levels of TAC, and catalase (CAT) activity were improved so the levels of ROS, MDA, and %DNA damage were reduced compared with varicocele group. Our findings indicated that the administration of lycopene especially at a dose of 10 mg/kg in the varicocele group could protect sperm from OS and sperm DNA damage by increasing antioxidant activity and reducing ROS.

The Effect of Oral Vitamin E on Semen Parameters and IVF Outcome: A Double-Blinded Randomized Placebo-Controlled Clinical Trial

Background

Male infertility is a main clinical problem that affects about 7% of all men worldwide. Many patients with male infertility are caused by a reduced antioxidant capacity of semen. Several antioxidant supplements, especially vitamin E, are proposed to help male infertility treatment. This project was goaled to study the effects of oral synthetic vitamin E (400 IU/day) for eight weeks on betterment of semen parameters and pregnancy rate.

Methods

After dropping the cases, 124 infertile couples with a male factor who were admitted to the IVF program were included. The male patients with idiopathic abnormal motility and/or morphology were randomized into two groups: 61 receiving vitamin E and 63 as the control group receiving placebo for eight weeks. The pretreatment semen parameters of both groups were compared with those of posttreatment. The pregnancy outcomes were considered between the two groups.

Results

There were no significant differences statistically between before and after treatment in the term of sperm volume, count, motility, and morphology. Furthermore, the IVF outcomes of the two groups were not different significantly, either. Interestingly, the percent of normal sperm in the placebo group was significantly decreased after eight weeks.

Conclusion

Vitamin E supplementation might neutralize free radical activity to keep sperm from more oxidative damages. Further studies regarding the influence of higher acceptable doses of vitamin E on semen characteristics and fertility rates are needed. This study was registered as a two-arm, blinded, randomized, placebo-controlled clinical trial (IRCTID: IRCT2014020616506N1, 2014-03-18).

Oxidative Stress: A Comprehensive Review of Biochemical, Molecular, and Genetic Aspects in the Pathogenesis and Management of Varicocele

Oxidative stress is a condition due to an imbalance between the concentrations of oxidants and antioxidants, and it is a well-recognized contributor in several male infertility conditions. Varicocele, a common vascular condition, may cause male infertility due to hyperthermia, hypoxia and/or exposure to toxic adrenal and renal metabolites. In this review, the mechanisms by which oxidative stress can affect cellular integrity and functions are described, along with molecular markers of cellular oxidative damage, and the most commonly performed techniques for their detection in seminal fluid. Moreover, we focus on the role of oxidative stress in the pathophysiology of varicocele based on recently published evidence from omics based studies, such as proteomics and genomics. Finally, we discuss strategies for the management of oxidative stress and the clinical guidelines for testing oxidative stress-related sperm DNA fragmentation in this group of patients.