The protective effect of epigallocatechin-3-gallate on testicular oxidative stress in lead-induced toxicity mediated by Cyp19 gene / estradiol level

Allicin and hesperidin protect sperm production from environmental toxins in mice

This study investigates the protective effects of Allicin (A), a bioactive compound from garlic, and Hesperidin (HSD), a citrus flavonoid, against reproductive damage induced by para-nonylphenol (p-NP), an environmental pollutant, in mice. Fifty 8- to 10-week-old NMRI mice were divided into five groups: a control group, a group exposed to p-NP, and three groups treated with p-NP plus either Allicin, Hesperidin, or both. Treatments lasted for 35 days. Researchers analyzed sperm count, viability, motility, DNA damage, and morphology, alongside testicular parenchyma markers like antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels. Hormone levels (testosterone, LH, and FSH), testicular histopathology, apoptosis-related gene expression, and fertility indices were also evaluated. Results showed that mice treated with Allicin, Hesperidin, or both had reduced abnormal sperm morphology and DNA damage, with improvements in sperm motility, viability, and membrane integrity compared to the p-NP group. Antioxidant enzyme activities (TAC, SOD, GPx) and hormone levels increased, while MDA levels decreased, indicating reduced oxidative stress. Furthermore, expression of pro-apoptotic genes Bax and caspase-3 declined, while anti-apoptotic Bcl-2 expression rose. Treated mice demonstrated higher fertility indices and hormone levels. These findings suggest Allicin and Hesperidin mitigate p-NP-induced testicular damage by enhancing antioxidant defenses and regulating cell death pathways.

Regulation and mechanism of Bletilla striata polysaccharide on delaying aging in Drosophila melanogaster

Bletilla striata polysaccharide (BSP) is a natural bioactive compound known for its promising health benefits, including antioxidant, immunomodulatory, and anti-inflammatory effects. However, its potential in combating aging remains largely unexplored. This study aims to investigate the anti-aging effects of BSP in the Drosophila melanogaster model. The results show that BSP supplementation significantly extends the lifespan of flies in a concentration-dependent manner, with the most pronounced effects observed at a concentration of 3 mg/mL. Lifespan extension is associated with enhanced antioxidative capacities, as evidenced by increased SOD and CAT activities, and decreased MDA content. Additionally, BSP ameliorates age-related symptoms, including improved climbing ability and enhanced intestinal barrier function. Furthermore, BSP supplementation enhances resistance to H2O2-induced oxidative and starvation stresses, attenuates the lead (Pb)-induced toxicity, and delays the onset of Alzheimer's phenotypes in flies. RNA-Seq analysis reveals that BSP supplementation leads to the differential expression of 992 genes. KEGG pathway analysis highlights significant changes in metabolic pathways, including galactose metabolism, starch and sucrose metabolism, and carbon metabolism. Key genes such as Mal-A1, Amy-d, Men-b, Pgm-1, Mdh1, and Hex-C are downregulated, while CG32026, CG11291, and Ald2 are upregulated. These findings suggest BSP exhibits significant anti-aging and protective properties, making it a potential therapeutic agent.

Beneficial effects of EGCG on boar sperm quality during liquid storage at 4 °C are mediated by DRD2 receptor

Epigallocatechin gallate (EGCG), a natural antioxidant, plays a vital role in modulating sperm function, yet its protective impact on boar spermatozoa during liquid preservation at 4 °C remains elusive. This study aimed to investigate the beneficial effects of EGCG on boar semen preservation, and elucidate the potential mechanism. Multiple parameters including sperm quality, anti-oxidative status, protein phosphorylation levels, membrane receptor and cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling pathways were analyzed using computer-assisted semen analysis system, Western blot and molecular docking techniques. Results revealed that supplementation with EGCG, particularly with 10 μg/mL, significantly increased sperm motility, acrosome integrity, mitochondrial membrane potential and intracellular ATP content. Moreover, EGCG enhanced the antioxidant defenses of sperm through eliminating excessive reactive oxygen species. Intriguingly, the antioxidant property of EGCG partly prevented protein dephosphorylation, thereby indirectly enhancing protein phosphorylation. Additionally, the dopamine receptor (DRD2) was detected in boar spermatozoa and inhibition of DRD2 greatly prevented EGCG-caused enhancement of protein phosphorylation levels and sperm motility, suggesting the role of DRD2 in regulation of the beneficial effects of EGCG. Molecular docking results indicated that EGCG has favorable binding interactions with the active sites of DRD2, involving crucial hydrogen bonding and hydrophobic interactions, further suggesting that EGCG might directly interact with DRD2, mediate protein phosphorylation via activating the DRD2/cAMP/PKA pathway and thus boost sperm motility. The present study is the first to explore the interacting cell-surface receptor of EGCG on boar sperm and provides comprehensive insights into the protective mechanism of EGCG during hypothermic liquid storage.

Perinatal exposure to lead alters male reproductive behaviour and immunoreactivity of androgen and oestrogen receptors in the brain

Lead (Pb) exposure during perinatal development alters testosterone (T) concentrations and delays puberty in children and laboratory rodents. In addition, exposure to the metal during adult life decreases T and libido in men and affects male reproductive behaviour (MRB) in rats. MRB is regulated by various brain nuclei including the medial preoptic area (MPOa) and the medial amygdala (MeA), in which T and oestradiol (E2) act through their respective androgen (AR) and oestrogen (ER) receptors. However, the mechanism by which MRB is affected by Pb exposure is not known. The objectives of the present study were to evaluate whether perinatal Pb exposure affects MRB and the number of cells immunoreactive to AR and ERα in the MPOa and the MeA. Male Wistar rats exposed to Pb (320 ppm) in drinking water from the beginning of pregnancy until weaning were used. The experimental group experienced significant alterations in MRB, an important decrease in T and E2 concentrations, and a significant increase in Pb concentrations in the blood, MPOa (hypothalamus) and MeA. In addition, in the studied areas the number of cells immunoreactive to AR and ERα, or detected using the Nissl technique, decreased significantly. These results show that perinatal exposure to Pb alters MRB. This event may be related to a decrease in both the concentrations of sex hormones and the number of cells that express their receptors as well as in the neuronal Nissl staining population. This ultimately affects the quality of life of the individual.

Natural antioxidants mitigate heavy metal induced reproductive toxicity: prospective mechanisms and biomarkers

Heavy metals are harmful environmental pollutants that have attracted widespread attention, attributed to their health hazards to humans and animals. Due to the non-degradable property of heavy metals, organisms are inevitably exposed to heavy metals such as arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg). Several studies revealed that heavy metals can cause reproductive damage by the excessive production of reactive oxygen species (ROS), which exacerbates oxidative stress, inflammation, and endocrine disruption. Natural antioxidants, mainly polyphenols, carotenoids, and vitamins, have been shown to mitigate heavy metal-induced reproductive toxicity potentially. In this review, accumulated evidences on the influences of four non-essential heavy metals As, Cd, Pb, and Hg on both males and females reproductive system were established. The purpose of this review is to explore the potential mechanisms of the effects of heavy metals on reproductive function and point out the potential biomarkers of natural antioxidants interventions toward heavy metal-induced reproductive toxicity. Notably, increasing evidence proven that the regulations of hypothalamic-pituitary-gonadal axis, Nrf2, MAPK, or NF-κB pathways are the important mechanisms for the amelioration of heavy metal induced reproductive toxicity by natural antioxidants. It also provided a promising guidance for prevention and management of heavy metal-induced reproductive toxicity.

Acetate attenuates lead-induced dysregulation of testicular steroidogenesis and spermatogenesis by targeting oxidative stress, inflammatory cytokines, and apoptosis

Lead exposure has been implicated in the aetiopathogenesis of male infertility via an oxidative stress-sensitive pathway. Conversely, acetate has been shown to confer cellular protection by improving the antioxidant defense mechanism. Yet, the effect of acetate on lead-induced testicular toxicity, viz., dysregulation of testicular steroidogenesis and spermatogenesis, has not been reported. The present study probed the influence of acetate on lead-induced dysregulation of testicular steroidogenesis and spermatogenesis. In our study, a reduction in body weight gain and testicular weight was identified in lead-exposed rats. While histopathological results established distortion of testicular histoarchitecture, reduced germ cell count, and suppressed spermatogenesis, biochemical studies confirmed that lead-deregulated testicular steroidogenesis was associated with reduced circulating gonadotropin-releasing hormone and gonadotropins, as well as down-regulated testicular 3β-HSD and 17β-HSD activities. These findings were accompanied by increased testicular malondialdehyde, TNF-α, IL-1β, and IL-6, and reduced glutathione, thiol and non-thiol protein levels, total antioxidant capacity, superoxide dismutase, and catalase activities. In addition, lead exposure increased NFkB and Bax levels, as well as caspase 3 activity, but reduced Bcl-2 levels. However, co-administration of acetate ameliorated lead-induced alterations. Collectively, acetate attenuated lead-induced dysregulation of testicular steroidogenesis and spermatogenesis by targeting oxidative stress, NFkB-mediated inflammation, and caspase 3-driven apoptosis.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43188-024-00250-3.

The emergence of natural products as potential therapeutics for male infertility

Infertility is a major reproductive health problem. Approximately 50% of all documented cases of infertility are attributable to male factors, such as poor testicular function and semen quality. The recent significant global decline in sperm counts has serious implications for male fertility, but the armamentarium for improving testicular function and semen quality is limited. Natural products have a wide range of activities and are a major source of drugs for disease prevention and treatment. To provide ideas and a theoretical basis for the research and development of therapeutic drugs for male infertility, this review summarizes natural products (mostly monomers) that have been shown to improve testicular function and semen quality and their possible mechanisms of action. These natural products primarily improve testicular function and semen quality via antioxidant, antiapoptotic, and anti-inflammatory effects, in addition to increasing serum testosterone and reducing DNA damage in spermatozoa and testicular cells. Prospects for the application of natural products in the treatment of male infertility are discussed.

Targeting JAK2/STAT3, NLRP3/Caspase-1, and PK2/PKR2 Pathways with Arbutin Ameliorates Lead Acetate-Induced Testicular Injury in Rats

The reproductive system of males is adversely impacted by lead (Pb), a toxic heavy metal. The present study examined arbutin, a promising hydroquinone glycoside, for its potential ameliorative impact against Pb-induced testicular impairment in rats. The testicular injury was induced by the intraperitoneal administration of Pb acetate (20 mg/kg/day) for 10 consecutive days. Thirty-six rats were divided into six experimental groups (n = 6 per group): control, control treated with oral arbutin (250 mg/kg), control treated with intraperitoneal arbutin (75 mg/kg), untreated Pb, Pb treated with oral arbutin, and Pb treated with intraperitoneal arbutin. The treatments were administered daily for 10 days. Arbutin was administered by the oral and intraperitoneal routes to compare the efficacy of both routes in mitigating Pb acetate-induced testicular dysfunction. The current data revealed that both oral and intraperitoneal administration of arbutin significantly enhanced serum testosterone and sperm count/motility, indicating the amelioration of testicular dysfunction. In tandem, both routes lowered testicular histopathological aberrations and Johnsen's damage scores. These favorable outcomes were driven by dampening testicular oxidative stress, evidenced by lowered lipid peroxidation and increased glutathione and catalase antioxidants. Moreover, arbutin lowered testicular p-JAK2 and p-STAT3 levels, confirming the inhibition of the JAK2/STAT3 pro-inflammatory pathway. In tandem, arbutin suppressed the testicular NLRP3/caspase-1/NF-B axis and augmented the cytoprotective PK2/PKR2 pathway. Notably, intraperitoneal arbutin at a lower dose prompted a more pronounced mitigation of Pb-induced testicular dysfunction compared to oral administration. In conclusion, arbutin ameliorates Pb-evoked testicular damage by stimulating testicular antioxidants and the PK2/PKR2 pathway and inhibiting the JAK2/STAT3 and NLRP3/caspase-1 pro-inflammatory pathways. Hence, arbutin may be used as an adjunct agent for mitigating Pb-induced testicular impairment.

Exposure to particulate matter may affect semen quality via trace metals: Evidence from a retrospective cohort study on fertile males

Particulate matter (PM) exposure may be associated with male semen quality. Besides, PM exposure induces up and down levels of trace metals in tissues or organs. The levels of trace metals in semen are critical for adverse male semen quality. This study aims to evaluate the concentrations of seminal-level trace metals in fertile men and assess its associations with PM exposure and to explore the mediation role of trace metals in seminal plasma plays in the relationship between PM exposure and semen quality. Total 1225 fertile men who participated in a cohort study from 2014 to 2016 were finally recruited. Multivariate linear regression was applied to explore associations between each two of PM exposure, trace metals and semen parameters. 1-year PM2.5 and PM10 exposure levels were positively associated with arsenic (As), mercury (Hg), lanthanum (La), praseodymium (Pr), neodymium (Nd) but negatively associated with vanadium (V), magnesium (Mg), strontium (Sr), barium (Ba) in semen. It was also found that most of the elements were associated with total sperm number, followed by sperm concentration. Redundancy analysis (RDA) also determined several strong positive correlations or negative correlations between 1-year PM exposure and trace metals. Mediation analysis found that trace metals had a potentially compensatory or synergetic indirect effect on the total effect of the association between 1-year PM exposure and semen quality. The retrospective cohort study provides long-term PM exposure that may cause abnormal semen quality by affecting seminal plasma element levels.

Zinc protects against lead-induced testicular damage via modulation of steroidogenic and xanthine oxidase/uric acid/caspase 3-mediated apoptotic signaling in male Wistar rats

AIM

This study evaluated the effect of lead, with or without zinc co-administration, on steroidogenic and xanthine oxidase (XO)/uric acid (UA)/caspase 3-mediated apoptotic signaling in the testis.

MATERIALS AND METHODS

Forty male Wistar rats were divided into four groups at random; vehicle-treated control, zinc-treated, lead-treated, and lead + zinc-treated groups.

RESULTS

Lead exposure significantly lowered overall weight gain, testicular, epididymal, seminal vesicle, and prostate weights. Also, lead decreased sperm count, viability and motility but increased the fraction of sperm with aberrant morphology. In addition, lead caused a marked rise in the level of UA and XO activity but a decrease in nuclear factor erythroid 2-related factor 2 (Nrf2), reduced glutathione (GSH) as well as total antioxidant capacity (TAC) levels, and superoxide dismutase (SOD) and catalase activities. Furthermore, lead increased the testicular levels of nuclear factor kappa B (NFkB), interleukin-1beta (IL-1β), and tumour necrotic factor-alpha (TNF-α), which were associated with an increase in testicular caspase 3 activity and DNA fragmentation as well as a decline in circulating gonadotropin releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and testicular 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD). These were associated with lead-induced degenerative changes in testicular tissues evidenced by shrunken seminiferous tubules, degeneration and sloughing of germ cells. Co-administration of zinc prevented lead-induced testicular injury by ameliorating oxidative stress, apoptosis, and inflammation through downregulation of XO/UA/caspase 3 pathway and upregulation of testicular 3β-HSD/17β-HSD.

CONCLUSION

This study demonstrated that zinc protected against lead-induced testicular toxicity via the downregulation of XO/UA/caspase 3 signaling.

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.

Melatonin or vitamin C attenuates lead acetate-induced testicular oxidative and inflammatory damage in mice by inhibiting oxidative stress mediated NF-κB signaling

Lead (Pb) acts as an environmental endocrine disruptor and has negative effects in animals; excessive accumulation of lead causes reproductive dysfunction in male animals. Oxidative stress plays a vital role in Pb-induced injury. However, the mechanisms underlying chronic testicular toxicity of Pb remain unclear. In this study, we aimed to determine the effects of lead acetate on reproductive function in male mice, identify the underlying mechanisms, and test counter measures to alleviate the toxic effects. Male mice were dosed with lead acetate (500 mg/L) in free drinking water for 12 weeks, and administered melatonin (5 mg/kg) or vitamin C (500 mg/kg) by intraperitoneal injection. Blood from the eyeball, testicles, and sperm from the caudal epididymis were collected after 12 weeks and analyzed. Pb exposure reduced sperm count and motility, increased sperm malformation (P < 0.01), disrupted testicular morphology and structure, and decreased the expression of steroid hormone synthesis-related enzymes and serum testosterone concentration (P < 0.01). Pb also increased the number of inflammatory cells and the levels of the pro-inflammatory cytokines TNF-α and IL-6 (P < 0.01), and activated NF-κB signaling. Furthermore, the ROS yield and oxidation indicators LPO and MDA were significantly increased (P < 0.01), and the antioxidant indicators T-AOC, SOD, and GSH were significantly reduced (P < 0.01). Treatment with melatonin or vitamin C reversed the effects of lead acetate; vitamin C was more effective in restoring SOD activity (P < 0.01) and enhancing ZO-1 protein levels (P < 0.01). Thus, long-term exposure to lead acetate at low concentrations could adversely affect sperm quality and induce inflammatory damage by oxidative stress mediated NF-κB signaling. Vitamin C could act as a protective agent and improve reproductive dysfunction in male animals after lead accumulation.

Protective effects of epigallocatechin gallate in the mice induced by chronic scrotal hyperthermia

One of the most common complications of chronic scrotal hyperthermia (SHT) is a serious disorder in the male reproductive system. The most important factor in the occurrence of these disorders is oxidative stress. Currently, we investigated the effects of epigallocatechin gallate (EGCG), as a highly potent antioxidant, against cells and tissue disorders in mice affected by chronic SHT. Fifty-six male adult NMRI mice were allocated into seven equal groups. Except the non-treated (Control) group, six other groups were exposed to heat stress. Two treated groups including Preventive and Curative received oral administration of EGCG (50 mg/kg/day) starting immediately before heat exposure and fifteen consecutive days after the end of the heat exposure, respectively. For each treated group, two subgroups including positive control (Pre/Cur + PC groups) and vehicle (Pre/Cur + vehicle groups) were considered. At the end of the study, sperm characteristics, testosterone levels, stereological parameters, apoptosis, oxidant state, and molecular assessments were performed. We found that the sperm parameters, testosterone levels, the numerical density of spermatogonia, primary spermatocytes, spermatids, sertoli, leydig cells, and seminiferous tubules, biochemical factors (except MDA), and expression of c-kit gene were significantly higher in the Preventive and Curative groups, especially in Preventive ones, compared to other groups (P < 0.05). This is while expression of HSP72 and NF-κβ genes, MDA levels, as well as density of apoptotic cells considerably decreased in both EGCG-treated groups compared to other groups and it was more pronounced in Preventive ones (P < 0.05). Generally, EGCG attenuated cellular and molecular disorders induced by heat stress in the testis and it was more pronounced in Preventive status.

Protective effect of Agaricus bisporus mushroom against maternal and fetal damage induced by lead administration during pregnancy in rats

INTRODUCTION

Lead (Pb) is a toxic pollutant, which can affect different tissues of the human body. The use of natural elements, as medicinal mushroom can reduce the toxic effects of Pb.

OBJECTIVE

We evaluated, through preclinical tests, the oral co exposures to mushroom Agaricus bisporus (Ab) by gavage and Pb in drinking water, and the capability of Ab be a protective agent for both pregnant rats and their fetuses.

METHODS

Female Wistar rats were divided into four groups (n = 5/group): Group I-Control; Group II-Ab 100 mg/kg; Group III-Pb 100 mg/L; Group IV-Ab +Pb -100 mg/kg +100 mg/L. Exposure was performed until the 19th day of gestation. On the 20th day, pregnant rats were euthanized, and the outcomes evaluated were weight gain; hematological profile; biochemical markers; oxidative stress markers; reproductive capacity; and embryo fetal development.

RESULTS

The characterization of mushrooms reveals them to be a valuable source of nutrients. However, Pb ingestion resulted in reduced weight gain and negative impacts on hematological and biochemical parameters. Fortunately, co administration of mushrooms helped to mitigate these negative effects and promote recovery. The mushroom also showed antioxidant activity, improving parameters of oxidative stress. In addition, Ab partially recovered the damage in fetal morphology and bone parameters.

CONCLUSION

Our findings indicated that the co administration of Ab improved the toxicity caused by Pb, and the mushroom could be used as a natural alternative as a protective/chelator agent.

The Palliative and Antioxidant Effects of Hesperidin against Lead-Acetate-Induced Testicular Injury in Male Wistar Rats

Lead (Pb)-induced reprotoxicity is a detrimental consequence of Pb exposure, which results in abnormal spermatogenesis, testicular degeneration, and pathogenic sperm changes. The association between impaired male reproductive function and Pb-induced oxidative stress (OS) has been demonstrated, with consequent testicular antioxidant deficiency. The current study investigated the protective role of the natural antioxidant hesperidin (HSD) against lead-acetate (PbAc)-induced testicular toxicity. Male Wistar rats (n = 40) were randomly divided into four experimental groups: Group I (negative control) received 2.0 mL/kg BW 0.9% saline; Group II received 100 mg/kg BW PbAc; Group III received 100 mg/kg BW HSD; and Group IV received HSD two hours before PbAc using the abovementioned doses. The treatments were administered daily for 30 consecutive days. The results showed that HSD treatment significantly restored PbAc-induced decrease in body, epididymal, and testicular weights as well as in semen parameters, reproductive hormones, and testicular markers of OS. Reduced MDA levels and improved testicular histopathological findings were also observed. Collectively, this study sheds light on the preventive role of HSD against PbAc-induced testicular injury, which is mediated via the suppression of OS and the modulation of reproductive hormones as well as the plausibility of HSD being used as a supplementary therapeutic option for recovery.

Mechanisms Underlying the Effects of the Green Tea Polyphenol EGCG in Sarcopenia Prevention and Management

Sarcopenia is prevalent among the older population and severely affects human health. Tea catechins may benefit for skeletal muscle performance and protect against secondary sarcopenia. However, the mechanisms underlying their antisarcopenic effect are still not fully understood. Despite initial successes in animal and early clinical trials regarding the safety and efficacy of (-)-epigallocatechin-3-gallate (EGCG), a major catechin of green tea, many challenges, problems, and unanswered questions remain. In this comprehensive review, we discuss the potential role and underlying mechanisms of EGCG in sarcopenia prevention and management. We thoroughly review the general biological activities and general effects of EGCG on skeletal muscle performance, EGCG's antisarcopenic mechanisms, and recent clinical evidence of the aforesaid effects and mechanisms. We also address safety issues and provide directions for future studies. The possible concerted actions of EGCG indicate the need for further studies on sarcopenia prevention and management in humans.

Epigallocatechin gallate alleviates mono-2-ethylhexyl phthalate-induced male germ cell pyroptosis by inhibiting the ROS/mTOR/NLRP3 pathway

Mono-2-ethylhexyl phthalate (MEHP) exposure is known to induce severe testicular injury via reactive oxygen species (ROS). However, few effective treatments are available for the precise treatment of MEHP-induced germ cell damage. Epigallocatechin gallate (EGCG), one of the major polyphenols in green tea, has potential antioxidant activity and can alleviate many diseases induced by oxidative stress. This study explored whether EGCG protects germ cells from MEHP-induced oxidative stress damage. Cells were treated with 400 μM MEHP and 60 μM EGCG for 24 h. EGCG reduced MEHP-induced ROS overgeneration in the spermatogonial cell line GC-1 and spermatocyte cell line GC-2. Western blotting and immunofluorescence showed that the MEHP+EGCG group exhibited lower nuclear factor (erythroid-derived 2)-like 2 (NRF2), heme oxygenase (decycling) 1 (HO-1), and superoxide dismutase (SOD) expression than the MEHP group. Moreover, activation of the mammalian target of rapamycin (mTOR) pathway was decreased. The expression of key factors of pyroptosis was downregulated, and interleukin-10 (IL-10) expression was reduced. Additionally, apoptosis was inhibited by EGCG. The findings indicate that EGCG protects against MEHP-induced germ cell pyroptosis by scavenging ROS, suppressing the mTOR pathway, and inhibiting pyroptosis. EGCG may thus be a potential treatment for MEHP-related spermatogenic dysfunction.

Hormonal regulation of health-promoting compounds in tea (Camellia sinensis L.)

Tea is the most frequently consumed natural beverage across the world produced with the young leaves and shoots of the evergreen perennial plant Camellia sinensis (L.) O. Kuntze. The expanding global appeal of tea is partly attributed to its health-promoting benefits such as anti-inflammation, anti-cancer, anti-allergy, anti-hypertension, anti-obesity, and anti- SARS-CoV-2 activity. The many advantages of healthy tea intake are linked to its bioactive substances such as tea polyphenols, flavonoids (catechins), amino acids (theanine), alkaloids (caffeine), anthocyanins, proanthocyanidins, etc. that are produced through secondary metabolic pathways. Phytohormones regulate secondary metabolite biosynthesis in a variety of plants, including tea. There is a strong hormonal response in the biosynthesis of polyphenols, catechins, theanine and caffeine in tea under control and perturbed environmental conditions. In addition to the impact of preharvest plant hormone manipulation on green tea quality, changes in hormones of postharvest tea also regulate quality-related metabolites in tea. In this review, we discuss the health benefits of major tea constituents and the role of various plant hormones in improving the endogenous levels of these compounds for human health benefits. The fact that the ratio of tea polyphenols to amino acids and the concentrations of tea components are changed by environmental conditions, most notably by climate change-associated variables, the selection and usage of optimal hormone combinations may aid in sustaining tea quality, and thus can be beneficial to both consumers and producers.

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.

Tea and coffee polyphenols and their biological properties based on the latest in vitro investigations

Tea and coffee contain numerous polyphenolic compounds that exhibit health-promoting properties for humans, including antioxidant and neuroprotective properties, and can also take part in the treatment of covid-19 and improve fertility. This review, presents the activity of polyphenols found in different types of tea and coffee and describes the effects of tea fermentation and coffee roasting on their polyphenol composition and antioxidant properties. Polyphenol oxidase activity is reduced in the fermentation process; therefore black tea contains significantly less polyphenolic compounds compared to green and white tea. Epigallocatechin-3-gallate - a polyphenol from tea - effectively has been shown to inhibit the activity of SARS-CoV-2 as it blocked binding of coronavirus 2 to human angiotensin converting enzyme 2, decreased the expression of inflammatory factors in the blood, including tumor necrosis factor-α and interleukin-6, and significantly increased the overall fertilization efficiency in animals. Coffee roasting process influences both the content of polyphenols and the oxidative activity. The lowest levels of active compounds such as caffeine, chlorogenic acid and coffee acids are identified in roasted coffee beans. On the other hand, light coffee and green coffee show the strongest cytotoxic potential and antioxidant properties, and thus the greatest ability to decrease apoptosis by stopping the cell cycle in the S phase. Proteins, such as components of milk, can strongly bind/interact with phenolic compounds (especially, the CGAs) contain in coffee, which may explain the negative influence of milk on its antioxidant properties. Coffee polyphenols have also antiproliferative and antiesterase activities, which may be important in prevention of cancer and neurodegenerative disorders, respectively. In this review, biological properties of tea and coffee polyphenols, observed mainly in in vitro studies have been described. Based on these findings, future directions of the research works on these compounds have been suggested.

Tea and coffee polyphenols and their biological properties based on the latest in vitro investigations

Tea and coffee contain numerous polyphenolic compounds that exhibit health-promoting properties for humans, including antioxidant and neuroprotective properties, and can also take part in the treatment of covid-19 and improve fertility. This review, presents the activity of polyphenols found in different types of tea and coffee and describes the effects of tea fermentation and coffee roasting on their polyphenol composition and antioxidant properties. Polyphenol oxidase activity is reduced in the fermentation process; therefore black tea contains significantly less polyphenolic compounds compared to green and white tea. Epigallocatechin-3-gallate - a polyphenol from tea - effectively has been shown to inhibit the activity of SARS-CoV-2 as it blocked binding of coronavirus 2 to human angiotensin converting enzyme 2, decreased the expression of inflammatory factors in the blood, including tumor necrosis factor-α and interleukin-6, and significantly increased the overall fertilization efficiency in animals. Coffee roasting process influences both the content of polyphenols and the oxidative activity. The lowest levels of active compounds such as caffeine, chlorogenic acid and coffee acids are identified in roasted coffee beans. On the other hand, light coffee and green coffee show the strongest cytotoxic potential and antioxidant properties, and thus the greatest ability to decrease apoptosis by stopping the cell cycle in the S phase. Proteins, such as components of milk, can strongly bind/interact with phenolic compounds (especially, the CGAs) contain in coffee, which may explain the negative influence of milk on its antioxidant properties. Coffee polyphenols have also antiproliferative and antiesterase activities, which may be important in prevention of cancer and neurodegenerative disorders, respectively. In this review, biological properties of tea and coffee polyphenols, observed mainly in in vitro studies have been described. Based on these findings, future directions of the research works on these compounds have been suggested.

Plant Polyphenols: Potential Antidotes for Lead Exposure

Lead is one of the most common heavy metal elements and has high biological toxicity. Long-term lead exposure will induce the contamination of animal feed, water, and food, which can cause chronic lead poisoning including nephrotoxicity, hepatotoxicity, neurotoxicity, and reproductive toxicity in humans and animals. In the past few decades, lead has caused widespread concern because of its significant threat to health. A large number of in vitro and animal experiments have shown that oxidative stress plays a key role in lead toxicity, and endoplasmic reticulum (ER) stress and the mitochondrial apoptosis pathway can also be induced by lead toxicity. Therefore, plant polyphenols have attracted attention, with their advantages of being natural antioxidants and having low toxicity. Plant polyphenols can resist lead toxicity by chelating lead with their special chemical molecular structure. In addition, scavenging active oxygen and improving the level of antioxidant enzymes, anti-inflammatory, and anti-apoptosis are also the key to relieving lead poisoning by plant polyphenols. Various plant polyphenols have been suggested to be useful in alleviating lead toxicity in animals and humans and are believed to have good application prospects.

Improvement roles of zinc supplementation in low dose lead induced testicular damage and glycolytic inhibition in mice

Lead (Pb) is a toxic metal that affects the male reproductive system. This study aimed to investigate the effects of zinc (Zn) intake between recommended dietary allowances (RDAs) and tolerable upper intake levels (ULs) in preventing male testis damage induced by low-dose Pb. Forty-five mice were randomly divided into control, Pb, and Pb + Zn groups. They were given distilled water ad libitum with 0, 200 mg/L Pb²⁺, or 15 mg/L Zn²⁺ mixed with 200 mg/L Pb²⁺ for 90 consecutive days. The Zn levels in the blood and testis of the Pb group were significantly lower than those of the control group. The Pb levels in the blood and testis of the Pb + Zn group were significantly lower than those of the Pb group. Additionally, a significant decrease in sperm density and viability, with a significant increase in sperm abnormality rate and DNA fragmentation index, was observed in the Pb group. Zn supplementation significantly improved the above sperm parameters. Moreover, Zn supplementation decreased low-dose Pb-induced lipid peroxidation and increased glutathione, total superoxide dismutase (SOD), and copper/Zn-SOD levels. Furthermore, Zn treatment improved glycolysis products and lactate transporters in Pb-treated mouse testes. Our findings suggest that Zn intake between RDAs and UL can act as a therapeutic agent in protecting against the reproductive impairments associated with Pb exposure.

Anthocyanin from purple sweet potato attenuates lead-induced reproductive toxicity mediated by JNK signaling pathway in male mice

The present work aimed to explore the protective effect of APSP on Pb-induced reproductive toxicity and possible mechanism. APSP (100 mg/kg) was administered to Pb-intoxicated (0.2% lead acetate) male Kunming mice once daily by oral gavage for 6 weeks. Our results showed that APSP exerted male reproductive protection effects as showed by attenuated Pb-induced testicular injury, improved sperm count and motility, and reduced sperm abnormality rate. APSP also restored Pb-induced decrease in both enzymatic and non-enzymatic antioxidants, and GSH/GSSG ratio, but inhibited lipid peroxidation in serum and testes. Moreover, APSP downregulated Pb-induced Bax mRNA and protein expressions, suppressed activation of caspase-3, upregulated Bcl-2 protein expression, and prevented Pb-induced DNA damage. APSP treatment also interfered with Pb-induced testicular JNK signaling through inhibition of JNK mRNA expression and phosphorylation, resulting in inhibition of c-Jun expression. These effects of APSP were abolished by Pb. In conclusion, APSP represents a potential therapeutic agent for preventing Pb-caused reproductive toxicity, which is attributed to its antioxidant and anti-apoptotic properties, as well as, modulation of JNK signaling pathway.

Pb induced mitochondrial fission of fibroblast cells via ATM activation

Previous study showed that lead (Pb) could induce ATM-dependent mitophagy. However, whether Pb has any impact on mitochondrial fusion and fission, the upstream events of mitophagy, and how ATM connects to these processes remain unclear. In this study, we found that Pb can disrupt mitochondrial network morphology as indicated by increased percentage of shortened mitochondria and by decreased mitochondrial footprints. Correspondingly, the expression of fission protein Drp1 and its association with mitochondrial marker Hsp60 were significantly increased, while those of fusion proteins Mfn2 and Opa1 and their co-localization with Hsp60 were drastically attenuated. Notably, the expression of p-Drp1 (Ser616) and its translocation to mitochondria were dramatically elevated. Moreover, a small amount of ATM could be detected in the cytoplasm around mitochondria in response to Pb, and the co-localization of p-ATM (Ser1981) with Drp1 and p-Drp1 (Ser616) was obviously increased while its co-localization with Mfn2 and Opa1 was dramatically decreased. Furthermore, siRNA silencing of ATM evidently promoted greater fission in response to Pb stress, indicating that ATM is involved in mitochondrial fragmentation. Our results suggest that cytoplasmic ATM is an important regulator of Pb-induced mitochondrial fission.

Green Tea Infusion Ameliorates Histological Damages in Testis and Epididymis of Diabetic Rats

Green tea is a popular drink used for therapeutic purposes to mitigate the consequences of diabetes. In this study, we aimed at evaluating the potential of green tea infusion to ameliorate structural and enzymatic damages caused by hyperglycemia in the testis and epididymis of Wistar rats. For that, nondiabetic and streptozotocin-induced diabetic rats (negative control and diabetes control, respectively) received 0.6 mL of water by gavage. Another set of diabetic animals received 100 mg/kg of green tea infusion diluted in 0.6 mL of water/gavage (diabetes + green tea) daily. After 42 days of treatment, the testes and epididymides were removed and processed for histopathological analysis, micromineral determination, and enzymatic assays. The results showed that treatment with green tea infusion preserved the testicular and epididymal histoarchitecture, improving the seminiferous epithelium and the sperm production previously affected by diabetes. Treatment with green tea reduced tissue damages caused by this metabolic condition. Given the severity of hyperglycemia, there was no efficacy of the green tea infusion in maintaining the testosterone levels, antioxidant enzyme activity, and microminerals content. Thus, our findings indicate a protective effect of this infusion on histological parameters, with possible use as a complementary therapy for diabetes.

Effect of Visnagin on Altered Steroidogenesis and Spermatogenesis, and Testicular Injury Induced by the Heavy Metal Lead

BACKGROUND

Lead (Pb) is an environmental pollutant causing serious health problems, including impairment of reproduction. Visnagin (VIS) is a furanochromone with promising antioxidant and anti-inflammatory effects; however, its protective efficacy against Pb toxicity has not been investigated.

OBJECTIVE

This study evaluated the protective effect of VIS on Pb reproductive toxicity, impaired steroidogenesis and spermatogenesis, oxidative stress and inflammation.

METHODS

Rats received VIS (30 or 60 mg/kg) and 50 mg/kg lead acetate for 3 weeks and blood and testes samples were collected.

RESULTS

Pb intoxication impaired the pituitary-testicular axis (PTA) manifested by the decreased serum levels of gonadotropins and testosterone. Pb decreased sperm count, motility and viability, increased sperm abnormalities, and downregulated the steroidogenesis markers StAR, CYP17A1, 3β-HSD and 17β-HSD in the testis of rats. VIS significantly increased serum gonadotropins and testosterone, alleviated sperm parameters and upregulated steroidogenesis. In addition, VIS decreased pro-inflammatory cytokines, testicular lipid peroxidation and DNA fragmentation, downregulated Bax, and enhanced antioxidants and Bcl-2.

CONCLUSION

These results demonstrate the protective effect of VIS against Pb reproductive toxicity in rats. VIS improved serum gonadotropins and testosterone, enhanced steroidogenesis and spermatogenesis, and attenuated oxidative injury, inflammation and apoptosis. Therefore, VIS is a promising candidate for the protection against Pb-induced reproduction impairment.

Epigallocatechin Gallate for Management of Heavy Metal-Induced Oxidative Stress: Mechanisms of Action, Efficacy, and Concerns

In this review, we highlight the effects of epigallocatechin gallate (EGCG) against toxicities induced by heavy metals (HMs). This most active green tea polyphenol was demonstrated to reduce HM toxicity in such cells and tissues as testis, liver, kidney, and neural cells. Several protective mechanisms that seem to play a pivotal role in EGCG-induced effects, including reactive oxygen species scavenging, HM chelation, activation of nuclear factor erythroid 2-related factor 2 (Nrf2), anti-inflammatory effects, and protection of mitochondria, are described. However, some studies, especially in vitro experiments, reported potentiation of harmful HM actions in the presence of EGCG. The adverse impact of EGCG on HM toxicity may be explained by such events as autooxidation of EGCG, EGCG-mediated iron (Fe3+) reduction, depletion of intracellular glutathione (GSH) levels, and disruption of mitochondrial functions. Furthermore, challenges hampering the potential EGCG application related to its low bioavailability and proper dosing are also discussed. Overall, in this review, we point out insights into mechanisms that might account for both the beneficial and adverse effects of EGCG in HM poisoning, which may have a bearing on the design of new therapeutics for HM intoxication therapy.

Research Progress on the Relationship between Obesity-Inflammation-Aromatase Axis and Male Infertility

Aromatase is a key enzyme in the transformation of androgen into estrogen. Its high expression will destroy the hormonal balance in the male body, and the excessive transformation of androgen into estrogen in the body will further damage the spermatogenic function of the testis, affect the normal development of the sperm, and cause spermatogenic disturbance. Adipose tissue has a high expression of aromatase and shows high enzymatic activity and ability to convert estrogen. Adipose tissue is the most estrogen-producing nongonadal tissue in the body because of its large size, accounting for about 20% of the body mass in healthy adults. PPARγ is recognized as the key adipose differentiation in the transcriptional regulation of the transcription factor. In the process of adipocyte differentiation, PPARγ regulate the expression of aromatase. The increase of aromatase is associated with the inflammatory response in adipose tissue caused by obesity. After obesity, the increase of proinflammatory factors in adipocytes will lead to enhanced transcription of the CYP19 gene encoding aromatase in adipocytes, which in turn will lead to increased expression of aromatase in adipocytes. This article reviews the regulation of male sterility from the angle of the "obesity-inflammation-aromatase" axis.

Chrysin protects against testicular toxicity caused by lead acetate in rats with its antioxidant, anti-inflammatory, and antiapoptotic properties

In the present study, the protective effects of chrysin (CHR) against testicular damage caused by lead acetate (PbAc) were examined. In this way, 30 min after rats were given 25 and 50 mg/kg/b.w CHR orally for seven consecutive days, 30 mg/kg/b.w PbAc was administered orally. In biochemical analysis of testicular tissue, it was found that PbAc-reduced antioxidant parameters [glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT)], while it increased lipid peroxidation, inflammatory markers [nuclear factor kappa-B (NF-κB), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE-2), and inducible nitric oxide synthase (iNOS)], and 8-hydroxy-2'-deoxyguanosine (8-OHdG). In the immunohistochemical examination, it was determined that PbAc increased the expression of tumor necrosis factor-α (TNF-α) and caspase-3. Accordingly, PbAc was found to cause a decrease in sperm motility and an increase in the percentage of dead sperm. However, it has been observed that CHR relieves oxidative stress due to its antioxidant properties, thus protecting against inflammation and apoptosis. It also allowed the CHR sperm parameters to return to control group levels. The results revealed that CHR could be a natural substance to be used in Pb-induced testicular toxicity. PRACTICAL APPLICATIONS: Lead (Pb) is an important environmental contaminant heavy metal. Pb is believed to reduce fertility in men. Oxidative stress plays a significant role in the damage caused by Pb to testicular tissue. CHR is an antioxidant substance that occurs naturally in various plants and has various pharmacological properties. In the present study, it was investigated whether CHR has a protective effect against testicular toxicity induced by PbAc. The results revealed that in rats, CHR protects the testicular tissue from PbAc toxicity by showing antioxidant, anti-inflammatory and anti-apoptotic effects, thus bringing sperm parameters closer to normal.

Interplay between male reproductive system dysfunction and the therapeutic effect of flavonoids

Male infertility has affected many families around the world. However, due to the mechanism underlying male reproductive system dysfunction are not completely elucidated, the use of drugs for male reproductive system dysfunction treatment only insignificant higher pregnancy outcomes, low-quality evidence suggests that clinical pregnancy rates may increase. Therefore, the focus in the future will be on developing more viable treatment options to prevent or treatment of male reproductive system dysfunction and achieve the purpose of improving fertility. Interestingly, natural products, as the potential inhibitors for the treatment of male reproductive system dysfunction, have shown a good therapeutic effect. Among many natural products, flavonoids have been extensively investigated for the treatment of male reproductive system dysfunction, such as testicular structural disruption, spermatogenesis disturbance and sperm quality decline. Flavonoids have been reported to have antioxidant, anti-inflammatory, immune stimulating, anti-apoptotic, anticarcinogenic, anti-allergic and antiviral activities, investigating for the treatment of male reproductive system dysfunction. In this review, we evaluate the therapeutic effects of flavonoids on male reproductive system dysfunction under different cellular scenarios and summarize the therapeutic strategies of flavonoids based on the aforementioned retrospective analysis. In the end, we describe some perspective research areas relevant to the application of flavonoids in the treatment of male reproductive system dysfunction.

Umbelliferone Inhibits Spermatogenic Defects and Testicular Injury in Lead-Intoxicated Rats by Suppressing Oxidative Stress and Inflammation, and Improving Nrf2/HO-1 Signaling

INTRODUCTION

Lead (Pb) is an environmental toxic metal that threatens human health. Umbelliferone (UMB) is a coumarin with known medicinal and protective properties against cytotoxicity. This study explored the ameliorative effect of UMB against Pb-induced testicular toxicity in rats, focusing on steroidogenesis, oxidative stress and inflammation.

MATERIALS AND METHODS

Rats received lead acetate (50 mg/kg) and UMB (25, 50 or 100 mg/kg) via oral gavage for 4 weeks.

RESULTS

Pb-intoxicated rats exhibited testicular tissue injury and decreased serum levels of LH, FSH and testosterone. The count, viability, motility and normal morphology of the sperms were decreased accompanied with downregulated steroidogenesis markers in Pb-induced group. UMB prevented testicular injury, increased serum levels of LH, FSH and testosterone, upregulated steroidogenesis markers and improved the semen quality. In addition, UMB attenuated oxidative stress and oxidative DNA damage, downregulated the expression of pro-inflammatory mediators and Bax, boosted antioxidant defenses and Bcl-2, and upregulated Nrf2/HO-1 signaling in Pb-intoxicated rats.

CONCLUSION

UMB prevents Pb-induced testicular injury by suppressing oxidative damage, inflammation and cell death, and boosting antioxidant defenses, Nrf2/HO-1 signaling and pituitary-gonadal axis. Thus, UMB may represent a protective and cost-effective agent against Pb testicular toxicity, pending further investigations to elucidate other underlying mechanisms.

Heavy metal exposure, oxidative stress and semen quality: Exploring associations and mediation effects in reproductive-aged men

BACKGROUND

Heavy metal exposure induces oxidative stress, which is critical for adverse male reproductive health.

OBJECTIVE

To explore the mediating effect of oxidative stress on the relationship of heavy metal exposure with semen quality.

METHODS

Urinary levels of three oxidative stress markers, semen quality, and urinary arsenic, cadmium and lead were examined among 1020 men. Multivariate linear regression was applied to explore cross-sectional associations, and the role of oxidative stress as mediators was investigated.

RESULTS

Quartiles of metals showed significant dose-dependent relationships with increasing levels of 8-hydroxy-2deoxyguanosine (8-OHdG), 8-iso-prostaglandin F2α (8-isoPGF2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA). Significant or suggestive associations were also found between urinary 8-OHdG levels and the percentage of normal sperm morphology (p_trend < 0.001), between urinary 8-isoPGF2α levels and total motility (p_trend = 0.052), progressive motility (p_trend = 0.050) respectively. The mediation analysis showed that about 14.59%, 18.06%, 15.35% or 16.49% of the association between arsenic/cadmium exposure and the decreased total motility/progressive motility was mediated by 8-isoPGF_2α, respectively. In addition, about 16.47% of the relationship between lead exposure and the decreased percentage of normal sperm morphology was mediated by 8-OHdG.

CONCLUSIONS

Our findings suggest that higher urinary arsenic, cadmium and lead levels were associated with increased oxidative stress markers, which also related with altered semen quality. 8-isoPGF_2α and 8-OHdG might be the possible mediators of the associations between urinary heavy metals and total motility, progressive motility or the proportion of normal sperm morphology.