Quercetin supplementation restores testicular function and augments germ cell survival in the estrogenized rats

El Gendy A, Serag A, Abd El-Fadeal NM, Abdel-Karim RI, Mostafa MM, El-Sheikh DH, Zayed MA. Acacia saligna extract alleviates quetiapine-induced sexual toxicity in male albino rats: Insights from UPLC-MS/MS metabolite profiling, structural and PI3K/NF-κB pathway assessments

Background

Quetiapine (QET) abuse has increased due to its anxiolytic and hedonic effects, necessitating protective adjunct treatments. Acacia saligna (A. saligna) flowers, used in traditional medicine, have potential health benefits.

Aim

To investigate the protective role of A. saligna flower extract against QET-induced sexual toxicity, and to elucidate the possible underlying mechanisms through metabolomic and physiological studies.

Methods

A. saligna extract was subjected to metabolite profiling via High-Resolution Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-ESI-qTOF-MS). Forty-eight adult male albino rats were assigned into six groups for 30 days. The intracavernosal pressure (ICP), semen, biochemical, hormonal, histological, genetic and Western blot (WB) analyses were determined.

Results

A. saligna extract is rich in phenolic compounds, flavonoids, tannins, and unsaturated fatty acids. QET significantly decreased ICP and negatively affected semen parameters. A. saligna mitigated decreased sperm motility and ameliorated overexpressed proinflammatory genes in QET-55 group. A. saligna ameliorated the reduction of the antioxidant biomarkers, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), concurrent with downregulation of the nuclear factor kappa B (NF-κB) protein. A. saligna counteracted the disrupted testicular and prostatic structures revealed by histological examination.

Conclusion

The extract from A. saligna, which contains a high concentration of antioxidants and anti-inflammatory chemicals, effectively mitigates sexual toxicity caused by QET. This study provided the first known explanation of the hypothesized processes behind the protective properties of A. saligna through biological, biochemical, and histological parameters. The results emphasize the potential of A. saligna as a safeguarding agent against drug-induced sexual toxicity.

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

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

Quercetin promotes the secretion of musk by regulating the hormone level and microbial structure of forest musk deer

Musk is a scarce and precious medical resource secreted by male forest musk deer (FMD). Current research to promote musk secretion in FMD has used almost exclusively hormone injections, but this approach can be detrimental to the health of FMD. In order to conserve this endangered species as much as possible while increasing the production of musk, this study first used bioinformatics methods to predict the function of quercetin, a flavonoid that promotes testosterone (T) production and prevents late-onset male hypogonadism. On the basis of good prediction effect, different concentrations of quercetin were added to the diet of FMD. The results showed that quercetin could change the levels of T, luteinizing hormone releasing hormone, luteinizing hormone, and estradiol, and regulate the structure of intestinal microorganisms and musk microorganisms of FMD. Moreover, there is a correlation among musk components, hormones, intestinal microorganisms, and musk microorganisms, which indicates that the production of musk may be regulated by these three at the same time, and the addition of quercetin with 800 mg per kg diet could significantly increase the yield of muscone (P < 0.05), the most effective ingredient in musk. In addition, quercetin decreased the high level of cortisol during musk secretion, which may relieve the stress on FMD in this process. This may help to protect the health of FMD. Combined with the results of software prediction, we finally proposed a possible mechanism for the complex process of musk secretion in FMD with a view to providing ideas for further studies.

Punica granatum peel extract modulates levofloxacin-induced oxidative stress and testicular damage in rats

Levofloxacin (LEV) is one of the Fluoroquinolones antibiotic groups, which are utilized in the therapy of numerous diseases, particularly in reproductive organs. Punica granatum peel is a waste byproduct rich in phytochemicals that are known for their different biological activities. The current research was designed to assess the capability of pomegranate peel extract (PGPE) in counteracting LEV-induced oxidative stress and testicular injury in rats. Rats groups were divided as follows: control, PGPE (500 mg/kg BW), LEV (300 mg/kg BW), and PGPE plus LEV. Rats were treated orally for two weeks daily. The chemical and nutritional content of Punica granatum peel (PGP) were investigated. GC/MS analysis showed the major phytochemical constituents in PGPE as gallic acid, ellagic acid, 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl, and caffeic acid with DPPH, ABTS, and NO radical scavenging activity, as well as Fe3+- reducing antioxidant activity. Results revealed that LEV increased TBARS and H2O2 concentrations and LDH activity in rat testes significantly. While the activities of antioxidant enzymes, phosphatases, aminotransferases, and reduced glutathione content as well as protein levels, were significantly reduced. Worthy changes in testosterone, luteinizing, and follicle-stimulating hormone levels, as well as sperm characteristics, were also discovered. LEV was also found to trigger apoptosis, as evidenced by elevated p53 and caspase-3 levels and decreased Bcl2 levels. Furthermore, alterations in histological and immunohistochemical PCNA expression were observed in rat testes, confirming the biochemical findings. Furthermore, PGPE pretreatment of LEV-treated rats restored the majority of the tested parameters when compared to the LEV-treated group. In conclusion, pomegranate peel extract had a powerful modulating role against the adverse effects of levofloxacin in rat testes and represents a perspective of the utilization of food waste by-products.

Enzymatically modified isoquercitrin in soy protein temporarily enhanced the plasma amino-acid concentrations, antioxidant index, and plasma hormone levels: a randomized, double-blind cross-over trial

This study investigated the effects of a dietary protein supplement containing enzymatically modified isoquercitrin (EMIQ) on plasma amino-acid levels in healthy people. A randomized double-blind cross-over trial (UMIN000044791) was conducted with a sample of nine healthy individuals. These participants ingested soy protein with or without 42 mg EMIQ for 7 days after performing mild exercise. Plasma amino-acid levels were measured before ingestion and at 15, 30, 45, 60, 90, 120, 180, and 240 min after ingestion on the last day. The concentrations of total amino acids at 0 and 120 min and easily oxidized amino acids at 120 min were significantly higher in the plasma of individuals who consumed 42 mg EMIQ. Oxidative stress levels were lower and plasma testosterone levels were higher in participants who ingested soy protein with 42 mg EMIQ than in those who did not. These results suggest that daily ingestion of soy protein with 42 mg EMIQ can be useful for effective protein absorption.

Quercetin Protects against Levetiracetam induced gonadotoxicity in rats

The purpose of this study was to determine whether quercetin may counteract the negative effects of levetiracetam on rat reproductive capabilities by examining its influence on a few reproductive parameters following levetiracetam administration. Twenty (20) experimental rats were employed, with five (n = 5) animals per treatment group. Rats in group 1 received saline (10mL/kg, p.o.) which served as control. Quercetin (20mg/kg, p.o./day) was given to groups 2 and 4 for 28 days starting from 29 to 56 days, respectively. However, animals in groups 3-4 received LEV (300mg/kg) once daily for 56 days with a 30-minute break in between treatments. All rats had their serum sex hormone levels, sperm characteristics, testicular antioxidant capability, and levels of oxido-inflammatory/apoptotic mediators evaluated. Additionally, the expression of proteins associated to BTB, autophagy, stress response was examined in rat testes. LEV increased sperm morphological defects and decreased sperm motility, sperm viability, sperm count body weight and testes weight, MDA and 8OHdG levels in the testis of LEV-treated rats were elevated, while antioxidant enzyme expression was concurrently decreased. Additionally, it reduced the levels of serum gonadotropins, testosterone, mitochondrial membrane potential, and cytochrome C liberation into the cytosol from the mitochondria. Caspase-3 and Caspase-9 activity increased. While Bcl-2, Cx-43, Nrf2, HO-1, mTOR, and Atg-7 levels were lowered, NOX-1, TNF-α, NF-kß, IL-1ß, and tDFI levels increased. Histopathological scoring provided further support for the decreased spermatogenesis. In contrast to all of these gonadotoxic effects of LEV, improvements in LEV-induced gonadal damage were seen through upregulation of Nrf2/ HO-1, Cx-43/NOX-1, mTOR/Atg-7 expression and attenuation of hypogonadism, poor sperm quality, mitochondria-mediated apoptosis, and oxidative inflammation due to quercetin post-treatment. The modulation of Nrf2/HO-1, /mTOR/Atg-7 and Cx-43/NOX-1 levels and the inhibition of mitochondria-mediated apoptosis and oxido-inflammation in LEV-induced gonadotoxicity in rats suggest that quercetin may hold promise as a possible therapeutic treatment.

Natural flavonoids exhibit potent anticancer activity by targeting microRNAs in cancer: A signature step hinting towards clinical perfection

Cancer prevalence and its rate of incidence are constantly rising since the past few decades. Owing to the toxicity of present-day antineoplastic drugs, it is imperative to explore safer and more effective molecules to combat and/or prevent this dreaded disease. Flavonoids, a class of polyphenols, have exhibited multifaceted implications against several diseases including cancer, without showing significant toxicity towards the normal cells. Shredded pieces of evidence suggest that flavonoids can enhance drug sensitivity and suppress proliferation, metastasis, and angiogenesis of cancer cells by modulating several oncogenic or oncosuppressor microRNAs (miRNAs, miRs). They play pivotal roles in regulation of various biological and pathological processes, including various cancers. In the present review, the structure, chemistry and miR targeting efficacy of quercetin, luteolin, silibinin, genistein, epigallocatechin gallate, and cyanidin against several cancer types are comprehensively discussed. miRs are considered as next-generation medicine of recent times, and their targeting by naturally occurring flavonoids in cancer cells could be deemed as a signature step. We anticipate that our compilations related to miRNA-mediated regulation of cancer cells by flavonoids might catapult the clinical investigations and affirmation in the future.

Quercetin Abates Aluminum Trioxide Nanoparticles and Lead Acetate Induced Altered Sperm Quality, Testicular Oxidative Damage, and Sexual Hormones Disruption in Male Rats

This study examined the effects of exposure to lead acetate (PbAc) and/or aluminum trioxide nanoparticles (Al₂O₃NPs) on testicular function. Additionally, the probable reproprotective effects of quercetin (QTN) against Al₂O₃NPs and PbAc co-exposure in male Sprague Dawely rats were assessed. Al₂O₃NPs (100 mg/kg b.wt.), PbAc (50 mg/kg b.wt.), and QTN (20 mg/kg b.wt.) were orally administered for 60 days. Then, spermiogram, histopathological examinations of the testis and accessory glands, and immunohistochemical detection of androgen receptors (AR) and tumor necrotic factor alpha (TNF-α) were achieved. Moreover, serum levels of male sex hormones and testicular levels of antioxidant indices were estimated. The results showed that Al₂O₃NP_s and/or PbAc caused significant sperm abnormalities, testicular oxidative stress, and histopathological changes. Furthermore, serum testosterone, LH, and FSH levels significantly decreased, while estradiol levels significantly increased. The Al₂O₃NPs and/or PbAc co-exposed group had more obvious disturbances. Furthermore, QTN co-administration significantly reversed the Al₂O₃NPs and PbAc-induced testicular histopathological alterations, reduced antioxidant defenses, and altered AR and TNF-α immune expression in testicular tissues. Conclusively, Al₂O₃NPs and/or PbAc evoked testicular dysfunction by inducing oxidative injury and inflammation. However, QTN oral dosing effectively mitigated the negative effects of Al₂O₃NPs and PbAc by suppressing oxidative stress and inflammation and improving the antioxidant defense system.

Pharmacological action of quercetin against testicular dysfunction: A mini review

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

Mediterranean Diet as a Shield against Male Infertility and Cancer Risk Induced by Environmental Pollutants: A Focus on Flavonoids

The role of environmental factors in influencing health status is well documented. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, ultrafine particles, produced by human activities put a strain on the body’s entire defense system. Therefore, together with public health measures, evidence-based individual resilience measures are necessary to mitigate cancer risk under environmental stress and to prevent reproductive dysfunction and non-communicable diseases; this is especially relevant for workers occupationally exposed to pollutants and/or populations residing in highly polluted areas. The Mediterranean diet is characterized by a high intake of fruits and vegetables rich in flavonoids, that can promote the elimination of pollutants in tissues and fluids and/or mitigate their effects through different mechanisms. In this review, we collected evidence from pre-clinical and clinical studies showing that the impairment of male fertility and gonadal development, as well as cancers of reproductive system, due to the exposure of organic and inorganic pollutants, may be counteracted by flavonoids.

Environmental heat stress in rabbits: implications and ameliorations

Profitable production of rabbit meat requires comfortable environment for expression of good quality traits embedded in the genetic components of rabbits. One of the major problems facing rabbit production is heat stress, especially in hot regions of the world. This is further aggravated by global warming being experienced as a result of climate change. Rabbits have no or few sweat glands, complicating the problem of heat dissipation, thereby predisposing the animals to heat stress (HS). Heat stress adversely affect welfare and adaptation, feed consumption and utilization, immunity and health status, growth, reproduction, and milk production in rabbits. Rabbits are homoeothermic animals. They should be capable of body temperature regulation within a narrow range. Thermoregulation is extremely poor in rabbits because of lack of sweat glands. Rabbits are highly sensitive to high ambient temperature. The presence of thick insulator fur on the skin further impedes heat loss in rabbits. This review summarizes data available literatures in the last two decades (2000-2020). Short compilation on management techniques adopted in rearing rabbits under hot conditions is included.

Regulatory effects of quercetin on testicular histopathology induced by cyanide in Wistar rats

Several causes of infertility have been identified, and several papers have documented some compounds that cause infertility. One of the compounds reported to be toxic to the reproductive system is cyanide. In the management of infertility, various mechanisms ranging from synthetic drugs, natural products and supplements have been employed. Quercetin is an antioxidant supplement that has been used in the treatment of a variety of ailments. This work is aimed at investigating the role of quercetin in attenuating spermato-toxicity and testicular-histopathology induced by cyanide.

Seventy-two (72) male wistar rat (weight 190 g ± 10 g) were divided into nine groups (n = 8) except for groups 4 and 5 with (n = 16). Group 1 (control) received physiological saline while Groups 2 and 3 received 0.5 and 1 mg/kg body weight (bwt) cyanide respectively for 56 days, groups 4 and 5 received 0.5 and 1 mg/kg bwt cyanide respectively for 30 days. At day 30, eight animals were sacrificed from Groups 4 and 5 and the remaining eight (8) rats were subdivided into groups (6 and 7) and were given 20 and 40 mg/kg bwt of quercetin respectively for twenty-six days. Co-administration of cyanide and quercetin at a dose of 0.5 mg/kg cyanide +20 mg/kg quercetin and 1 mg/kg cyanide +40 mg/kg quercetin were given to group 8 and 9 respectively for 56 days.

Significant decreases in sperm parameters (count, motile and normal sperm) and increases in malondiadehyde concentration were observed in the cyanide treated groups. Testicular histoarchitecture showed few to no spermatozoa in the lumen of rats treated with cyanide. All these effects were attenuated by quercetin.

In conclusion, quercetin regulates testicular histopathology induced by cyanide in Wistar rats. Data from this work suggests potential preventive or therapeutic applications of quercetin for individuals subjected to cyanide environmental pollution.

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.

Impact of quercetin supplementation on testicular functions in summer heat-stressed rabbits

<p>The current study was designed to determine the effects of dietary quercetin on epididymal sperm and testicular changes in male rabbits during summer heat stress (HS). Twelve adult male New Zealand white rabbits were submitted to summer heat conditions (temperature-humidity index 29.9±1.2). One group was fed a basal ration (BR; n = 6), whereas the other group was fed the same basal diet supplemented with quercetin (30 mg/kg d; Que-BR; n = 6) for 60 d, and both groups were sacrificed at the end of the experiment. Epididymis and testicles isolation was done for sperm, histopathology and apoptosis assessments. The results showed that quercetin improved epididymis weight, but did not affect other testicular dimensions except testicular length. A significant improvement was observed in epididymal sperm motility, concentration, kinematic parameters, viability, mitochondrial potential and acrosome integrity in Que-BR compared to the BR group. Lowered serum malondialdehyde level was observed in quercetin supplemented rabbits. Moreover, the quercetin supplementation maintained the interstitial stroma, seminiferous tubules architecture, germinal and Sertoli cells under HS, decreasing the apoptotic germ cell rate in seminiferous tubules. In conclusion, HS condition affects the sperm and testes configurations in rabbits and dietary quercetin minimises oxidative stress, which in turn protects the testes and sperm against HS induced damage.</p>

Effects of quercetin, sitagliptin alone or in combination in testicular toxicity induced by doxorubicin in rats

Objective

This study aimed to evaluate the effect of quercetin and/or sitagliptin on testicular damage induced by doxorubicin (DOX).

Methodology

Twenty-five male Wistar rats, weighing 240±20 g, were randomly divided into five groups as follows: a negative control group; that was treated with 1 mL of 0.9% sodium chloride; a DOX-treated group received Intraperitoneal (I.P.) DOX injection (3 mg/kg); a group treated with quercetin 80 mg/kg + sitagliptin 10 mg/kg + DOX; a group treated with quercetin 80 mg/kg + DOX; and a group treated with sitagliptin 10 mg/kg+ DOX. All treatment were given orally daily for 21 days with I.P. DOX 3 mg/kg injection for the treatment groups at days 8, 10, 12, 15, 17, and 19. On day 22, blood was collected for analysis of testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glutathione peroxidase (GPx), and total antioxidant capacity (TAOC). The testes were also removed and sent for histopathological examination.

Results

The study revealed that the combination of quercetin with sitagliptin produced a significant increase in testosterone and FSH levels with a non-significant increase in LH level. This combination also non-significantly decreased the level of ALP and LDH and restored the GPx level with enhancing TAOC.

Conclusion

The results suggest quercetin/sitagliptin combination as a promising therapeutic modality for attenuation of DOX-induced testicular toxicity in rats, and the main mechanism involved in such effect could be due to the antioxidant and anti-inflammatory properties of both agents.

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In vitro antioxidation effect of Quercetin on sperm function from the infertile patients with leukocytospermia

PROBLEM

Quercetin has been shown to display intensive antioxidant activity against ROS-mediated damage in chilled semen, and the effects and molecular mechanisms of Quercetin on sperm function in the infertile patients with leukocytospermia remain largely unknown.

METHODS

Semen samples were collected from the infertile men with leukocytospermia (n = 56) and fertile men (n = 44). Computer-assisted semen analysis (CASA) was used to determine sperm motility before and after Quercetin incubation (10 μmol/L). Changes in H₂ O₂ , sperm mitochondrial DNA (mtDNA), cytochrome B (Cty B), and NADH dehydrogenase 5 (NADH5) contents were measured. Furthermore, hyperactivated motility (HA) and acrosome reaction rates were detected after the stimulation by progesterone with or without Quercetin, respectively.

RESULTS

Quercetin could significantly improve sperm motility from the leukocytospermic patients. The level of H₂ O₂ was significantly decreased in the supernatant of leukocytospermic patients after Quercetin treatment. The content of mtDNA in sperm was significantly decreased, whereas the contents of Cyt B and NADH 5 in sperm were significantly increased. Sperm hyperactivated motility and acrosome reaction induced by progesterone were enhanced by Quercetin in sperm from the infertile men with leukocytospermia.

CONCLUSION

These data indicate Quercetin could display protective effects against oxidative damage on sperm from the infertile men with leukocytospermia.

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

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

Dietary quercetin maintains the semen quality in rabbits under summer heat stress

This study focused to determine beneficial impact of feeding quercetin supplemented diet on semen quality in summer heat imposed rabbits. Twelve heat stressed (HS) adult rabbits bucks were either fed with basal diet (HS; n = 06) or quercetin supplemented diet (QU-HS; n = 06) for a period of 56 days. Semen samples were collected and evaluated for volume, osmolality, morphology, concentration, motility, motion kinetics, viability, acrosome integrity, mitochondrial potential, and seminal plasma MDA level. Semen volume, concentration, motility and sperm kinetics parameters were affected by diet supplementation. Diet affected the sperm mitochondrial potential and day of treatment affected the viable sperm percentage. There was an effect of diet, day of treatment and diet by day interaction on acrosome reaction rate. Sperm head abnormalities were influenced by diet provision, sperm mid-piece abnormalities were affected by diet and day of treatment, whereas, the effect of diet and diet by day of treatment interaction were observed for total sperm abnormalities. There was an effect of diet and diet by day interaction for seminal plasma MDA level. In conclusions, quercetin reduces the damaging effects of HS and maintains the semen quality by lowering the oxidative stress in rabbits.

Dose- dependent ameliorative effects of quercetin and l-Carnitine against atrazine- induced reproductive toxicity in adult male Albino rats

This study aimed to determine the protective effects of co-administration of Quercetin (QT) or l-Carnitine (LC) against the oxidative stress induced by Atrazine (ATZ) in the reproductive system of intact male Albino rats. 36 rats were divided equally into 6 groups. Rats in the control negative "CNT" group received 1.5 ml distilled water for 21 days. All rats in the other groups received ATZ (120 mg/kg bw) through gavage. Groups 3 and 4 were co-administered with either low or high dose of QT (10 "ATZLQT" and 50 "ATZHQT" mg/kg bw, respectively). Groups 5 and 6 were co-administered with either low or high dose of LC (200 "ATZLLC" and 400 "ATZHLC" mg/kg bw, respectively). At the end of the experiment, animals were sacrificed and all samples were collected. ATZ significantly increased serum level of malondialdehyde (MDA) and decreased total antioxidant capacity (TAC). Also, ATZ increased significantly the sperm cell abnormalities and reduced both testicular IgA and serum testosterone levels. Testicular DNA laddering % and CYP17A1 mRNA expression were significantly reduced in ATZ group. Interestingly, co-administration with low dose QT or different doses of LC succeeded to counteract the negative toxic effects of ATZ on serum oxidative stress indicators, serum testosterone levels, testicular IgA level and improved testicular CYP17A1 mRNA expression. In conclusion, QT in low dose and LC in both low and high doses exerted a significant protective action against the reproductive toxicity of ATZ, while higher dose of QT failed induce immune-stimulant effect against ATZ in adult male Albino rats.

Indian propolis ameliorates the mitomycin C-induced testicular toxicity by reducing DNA damage and elevating the antioxidant activity

Development of excellent curative therapy for most of the malignancies has resulted in a growing population of cancer survivors who are at increased risk for a variety of health problems including infertility. Therefore, fertility preservation has become an important issue during cancer treatment in recent years. Combination therapy with natural agents such as vitamins, antioxidants, dietary supplements, and plant products are considered as an attractive option to mitigate normal tissue toxicity imparted by chemotherapy. The aim of the present study was to explore the beneficial effect of hydroethanolic extract of Indian propolis (HEIP) on mitigating mitomycin C (MMC)-induced testicular damage and its mechanism of action. Healthy adult male mice were injected intraperitoneally with saline, MMC, HEIP and HEIP followed by MMC after 1h. The animals were dissected at 35days after various treatments to analyze testicular function. MMC administration resulted in significant reduction in testicular function in a dose-dependent manner at 35days after treatment which significantly improved by HEIP pre-treatment. At 24h after treatment, MMC induced significant increase in oxidative stress, γ-H2AX foci and expression of RAD51 and KU80 in testicular cells. Prior treatment with HEIP decreased the oxidative stress, reduced DNA damage and restored the testicular testosterone and inhibin B level. In conclusion, co-administration of Indian propolis extract may play a promising beneficial role in fertility preservation of males undergoing chemotherapy.

Cytoprotective effects of dietary flavonoids against cadmium-induced toxicity

Cadmium (Cd) damages the liver, kidney, bones, reproductive system, and other organs. Flavonoids, such as anthocyanins and flavonols, which are commonly found in plant foods, have shown protective effects against Cd-induced damage. The cytoprotective effects of flavonoids against Cd-induced diseases are mainly attributable to three mechanisms. First, flavonoids clear reactive oxygen species, thereby reducing lipid peroxide production and improving the activity of antioxidation enzymes. Second, flavonoids chelate Cd, thus reducing the accumulation of Cd and altering the levels of other essential metal ions in vivo. Third, flavonoids reduce DNA damage and inhibit apoptosis. In addition, flavonoids were found to inhibit inflammation and fibrosis and improve glycometabolism and the secretion of reproductive hormones. We introduce the daily dosage and absorption rate of flavonoids and then focus on their bioactive effects against Cd-induced toxicity and reveal the underlying metabolic pathway, which provides a basis for further study of the nutritional prevention of Cd-induced injury. In particular, a better understanding is needed of the structure-activity relationship of flavonoids against Cd toxicity, which has not yet been reported.

Beneficial effects of quercetin on titanium dioxide nanoparticles induced spermatogenesis defects in mice

Many recent studies have demonstrated that most nanoparticles (NPs) have an adverse or toxic action on male germ cells. In present study, protective effect of quercetin (Que) on titanium dioxide nanoparticle (NTiO₂)-induced spermatogenesis defects in mice was investigated. Thirty-two Naval Medical Research Institute (NMRI) mice were randomly divided into four groups. Que group received 75 mg/kg of Que for 42 days. NTiO₂ group received 300 mg/kg NTiO₂ for 35 days. NTiO₂ + Que group initially received 75 mg/kg Que for 7 days and was followed by concomitant administration of 300 mg/kg NTiO₂ for 35 days. Control group received only normal saline for 42 days. Sperm parameters, testosterone concentration, histological criteria, and apoptotic index were assessed. Product of lipid peroxidation (MDA), superoxide dismutase (SOD), and catalase (CAT) activities were also evaluated for oxidative stress in testicular tissue. Administration of NTiO₂ significantly induced histological changes in testicular tissue; increased apoptotic index; and decreased testicular weight, testosterone concentration, and sperm quality (p < 0.01). In the testis, NTiO₂ increased oxidative stress through an increase in lipid peroxidation and a decrease in SOD and CAT activities (p < 0.05). Que pretreatment could significantly attenuate testicular weight; apoptotic index; and histological criteria including vacuolization, detachment, and sloughing of germ cells in seminiferous tubules. Serum and tissue testosterone levels were significantly increased in Que-pretreated mice (p < 0.01). Sperm parameters including sperm number, motility, and percentage of abnormality were also effectively improved by Que pretreatment (p < 0.01). Pretreatment of Que significantly ameliorated oxidative stress and increased the activities of SOD and CAT in testicular tissue. These results indicate that sperm production can be increased by Que pretreatment in NTiO₂-intoxicated mice. The improved sperm quality and reverse testis histology by Que pretreatment may be a consequence of elevation testosterone concentration, reduction in germ cell apoptosis, and suppression of oxidative stress in testicular tissue.

Geroprotective and Radioprotective Activity of Quercetin, (-)-Epicatechin, and Ibuprofen in Drosophila melanogaster

The modulation of longevity genes and aging-associated signaling pathways using pharmacological agents is one of the potential ways to prolong the lifespan and increase the vitality of an organism. Phytochemicals flavonoids and non-steroidal anti-inflammatory drugs have a large potential as geroprotectors. The goal of the present study was to investigate the effects of long-term and short-term consumption of quercetin, (-)-epicatechin, and ibuprofen on the lifespan, resistance to stress factors (paraquat, hyperthermia, γ-radiation, and starvation), as well as age-dependent physiological parameters (locomotor activity and fecundity) of Drosophila melanogaster. The long-term treatment with quercetin and (-)-epicatechin didn't change or decreased the lifespan of males and females. In contrast, the short-term treatment with flavonoids had a beneficial effect and stimulated the resistance to paraquat and acute γ-irradiation. The short-term ibuprofen consumption had a positive effect on the lifespan of females when it was carried out at the middle age (30–40 days), and to the survival of flies under conditions of oxidative and genotoxic stresses. However, it didn't change the lifespan of males and females after the treatment during first 10 days of an imago life. Additionally, quercetin, (-)-epicatechin, and ibuprofen decreased the spontaneous locomotor activity of males, but had no effect of stimulated the physical activity and fecundity of females. Revealed quercetin, (-)-epicatechin, and ibuprofen activity can be associated with the stimulation of stress response mechanisms through the activation of pro-longevity pathways, or the induction of hormesis.

Differential roles of estrogen receptors, ESR1 and ESR2, in adult rat spermatogenesis

Estrogens, through their receptors, play an important role in regulation of spermatogenesis. However, the precise role of the estrogen receptors (ESR1 and ESR2) has been difficult to determine as in vivo estradiol treatment would signal through both the ESRs. Hence we had developed in vivo selective ESR agonist administration models in adult male rats to decipher the individual roles of the ESRs. Treatment with both ESR1 and ESR2 agonists decreased sperm counts after 60 days of treatment. The present study aimed to delineate the precise causes of decreased sperm counts following treatment with the two ESR agonists. Treatment with ESR1 agonist causes an arrest in differentiation of round spermatids into elongated spermatids, mainly due to down-regulation of genes involved in spermiogenesis. ESR2 agonist administration reduces sperm counts due to spermiation failure and spermatocyte apoptosis. Spermiation failure observed is due to defects in tubulobulbar complex formation because of decrease in expression of genes involved in actin remodelling. The increase in spermatocyte apoptosis could be due to increase in oxidative stress and decrease in transcripts of anti-apoptotic genes. Our results suggest that the two ESRs regulate distinct aspects of spermatogenesis. ESR1 is mainly involved with regulation of spermiogenesis, while ESR2 regulates spermatocyte apoptosis and spermiation. Activation of estrogen signaling through either of the receptors can affect their respective processes during spermatogenesis and lead to low sperm output. Since many environmental estrogens can bind to the two ESRs with different affinities, these observations can be useful in understanding their potential effects on spermatogenesis.

Effect of Quercetin-loaded liposomes on induced oxidative stress in human spermatozoa

A strategy to circumvent the poor polyphenols bioavailability is to load these compounds into liposomes. We evaluated the in vitro effects of quercetin (Q) and Q-loaded liposomes (QLL, 30, 50, 100μM) on motility, viability and chromatin integrity of swim-up selected human sperm. Antioxidant power was assayed against tert-butylhydroperoxide induced lipid peroxidation (LPO) using C11-BODIPY581/591 fluorescent probe and transmission electron microscopy. QLL showed decreased toxicity for sperm motility and viability and increased DNA damage compared to Q. The percentage of sperm with fluorescence, marker of LPO, was decreased in samples incubated with Q vs QLL (P<0.001). The ultrastructure of acrosomes and membranes was preserved with Q 30/100μM, whereas QLL did not prevent membrane injury. Q alone appeared more effective than Q incorporated into liposomes; however liposomes could be considered as carriers that may convey different compounds inside sperm; they may therefore represent a field of research rich of many applications.

Therapeutic Potential of Date Palm Pollen for Testicular Dysfunction Induced by Thyroid Disorders in Male Rats

Hyper- or hypothyroidism can impair testicular function leading to infertility. The present study was designed to examine the protective effect of date palm pollen (DPP) extract on thyroid disorder-induced testicular dysfunction. Rats were divided into six groups. Group I was normal control. Group II received oral DPP extract (150 mg kg^-1), group III (hyperthyroid group) received intraperitoneal injection of L-thyroxine (L-T4, 300μg kg^-1; i.p.), group IV received L-T4 plus DPP extract, group V (hypothyroid group) received propylthiouracil (PTU, 10 mg kg^-1; i.p.) and group VI received PTU plus DPP extract. All treatments were given every day for 56 days. L-T4 or PTU lowered genital sex organs weight, sperm count and motility, serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone (T), testicular function markers and activities of testicular 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD). Moreover, L-T4 or PTU increased estradiol (E2) serum level, testicular oxidative stress, DNA damage and apoptotic markers. Morphometric and histopathologic studies backed these observations. Treatment with DPP extract prevented LT4- or PTU induced changes. In addition, supplementation of DPP extract to normal rats augmented sperm count and motility, serum levels of LH, T and E2 paralleled with increased activities of 3β-HSD and 17β-HSD as well as testicular antioxidant status. These results provide evidence that DPP extract may have potential protective effects on testicular dysfunction induced by altered thyroid hormones.

Effects of motor vehicle exhaust on male reproductive function and associated proteins

Air pollution is consistently associated with various diseases and subsequent death among children, adult, and elderly people worldwide. Motor vehicle exhaust contributes to a large proportion of the air pollution present. The motor vehicle exhaust systems emit a variety of toxic components, including carbon monoxide, nitrogen oxides, volatile organic compounds, ozone, particulate matter, and polycyclic aromatic hydrocarbons. Several epidemiological studies and laboratory studies have demonstrated that these components are potentially mutagenic, carcinogenic, and endocrine disrupting agents. However, their impact on male reproductive function and associated proteins is not very clear. Therefore, a comprehensive review on the effects of motor vehicle exhaust on male reproductive function and associated proteins is needed to better understand the risks of exhaust exposure for men. We found that motor vehicle exhaust can cause harmful effects on male reproductive functions by altering organ weights, reducing the spermatozoa qualities, and inducing oxidative stress. Remarkably, motor vehicle exhaust exposure causes significant changes in the expression patterns of proteins that are key components involved in spermatogenesis and testosterone synthesis. In conclusion, this review helps to describe the risks of vehicle exhaust exposure and its relationship to potential adverse effects on the male reproduction system.