The expression of glutathione reductase in the male reproductive system of rats supports the enzymatic basis of glutathione function in spermatogenesis

Ferroptosis: From regulation of lipid peroxidation to the treatment of diseases

Ferroptosis is a regulated cell death mainly manifested by iron-dependent lipid peroxide accumulation. The leading cause of ferroptosis is the imbalance of intracellular oxidative systems (e.g., LOXs, POR, ROS) and antioxidant systems (e.g., GSH/GPx4, CoQ10/FSP1, BH4/GCH1), which is regulated by a complex network. In the past decade, this metabolic network has been continuously refined, and the links with various pathophysiological processes have been gradually established. Apoptosis has been regarded as the only form of regulated cell death for a long time, and the application of chemotherapeutic drugs to induce apoptosis of cancer cells is the mainstream method. However, studies have reported that cancer cells' key features are resistance to apoptosis and chemotherapeutics. For high proliferation, cancer cells often have very active lipid metabolism and iron metabolism, which pave the way for ferroptosis. Interestingly, researchers found that drug-resistant or highly aggressive cancer cells are more prone to ferroptosis. Therefore, ferroptosis may be a potential strategy to eliminate cancer cells. In addition, links between ferroptosis and other diseases, such as neurological disorders and ischemia-reperfusion injury, have also been found. Understanding these diseases from the perspective of ferroptosis may provide new insights into clinical treatment. Herein, the metabolic processes in ferroptosis are reviewed, and the potential mechanisms and targets of ferroptosis in different diseases are summarized.

Eriodictyol attenuates Furan induced testicular toxicity in Rats: Role of oxidative stress, steroidogenic enzymes and apoptosis

Furan (C₄H₄O) is a naturally occurring organic compound. It develops as a result of the thermal processing of food and stimulates critical impairments in male reproductive tract. Eriodictyol (Etyol) is a natural dietary flavonoid possessing diverse pharmacological potentials. The recent investigation was proposed to ascertain the ameliorative potential of eriodictyol against furan-instigated reproductive dysfunctions. Male rats (n = 48) were classified into 4 groups: untreated/control, furan (10 mg/kg), furan+ eriodictyol (10 mg/kg + 20 mg/kg) and eriodictyol (20 mg/kg). At the 56th day of the trial, the protective effects of eriodictyol were evaluated by assessing various parameters. Results of the study revealed that eriodictyol attenuated furan-induced testicular toxicity in the biochemical profile by increasing catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) along with glutathione reductase (GSR) activities, whereas reduced the reactive oxygen species (ROS) along with malondialdehyde (MDA) levels. It also restored the normal state of sperm motility, viability, the count of hypo-osmotic tail swelled sperm as well as epididymal sperm number along with reduced sperm anomalies (morphological) tail, mid-piece and head. Furthermore, it elevated the decreased levels of luteinizing hormone (LH), plasma testosterone and follicle-stimulating hormone (FSH) as well steroidogenic enzymes (17β-HSD, StAR protein & 3β-HSD) and testicular anti-apoptotic marker (Bcl-2) expression, whereas, down-regulating apoptotic markers (Bax & Caspase-3) expression. Eriodictyol treatment also effectively mitigated the histopathological damages. The outcomes of the current study provide fundamental insights into the ameliorative potential of eriodictyol against furan-instigated testicular toxicity.

Ferroptosis: A Novel Type of Cell Death in Male Reproduction

Ferroptosis, an iron-dependent type of regulated cell death, is triggered by the accumulation of lethal lipid peroxides. Due to its potential in exploring disease progression and highly targeted therapies, it is still a widely discussed topic nowadays. In recent studies, it was found that ferroptosis was induced when testicular tissue was exposed to some high-risk factors, such as cadmium (Cd), busulfan, and smoking accompanied by a variety of reproductive damage characteristics, including changes in the specific morphology and ferroptosis-related features. In this literature-based review, we summarize the related mechanisms of ferroptosis and elaborate upon its relationship network in the male reproductive system in terms of three significant events: the abnormal iron metabolism, dysregulation of the Cyst(e)ine/GSH/GPX4 axis, and lipid peroxidation. It is meaningful to deeply explore the relationship between ferroptosis and the male reproductive system, which may provide suggestions regarding pristine therapeutic targets and novel drugs.

Investigation of Changes in Spermatozoon Characteristics, Chromatin Structure, and Antioxidant/Oxidant Parameters after Freeze-Thawing of Hesperidin (Vitamin P) Doses Added to Ram Semen

We conducted this study to determine the potential cryopreservative effects of different hesperidin (vitamin P; H) doses on ram semen after freeze-thawing. Semen samples were obtained from Sönmez rams using an artificial vagina. The samples were divided into six groups: control, 10, 50, 100, 250, and 500 µg/mL H (C, H10, H50, H100, H250, and H500, respectively). At the end of the study, sperm motility and kinetic parameters, acrosome integrity (AI), mitochondrial membrane potential (MMP), viability, lipid peroxidation levels (LPL), chromatin damage, oxidant parameters, and antioxidant parameters were assayed. None of the doses of H added to the semen extender showed any enhancing effects on progressive motility compared to C (p > 0.05). In fact, H500 had negative effects (p < 0.05). Moreover, AI was the highest at the H10 dose, while LPL values were the lowest at the same dose (p < 0.05). The doses of H10 and H50 added to the Tris extender medium showed positive effects on sperm cell chromatin damage. Consequently, we can say that H doses used in this study are not effective on semen progressive motility, but the H10 dose is effective on AI and chromatin damage by reducing LPL.

Protective role of Codiaeum variegatum against genotoxicity induced by carmustine in somatic and germ cells of male mice

Background

Carmustine (Cr) is an important chemotherapeutic drug, widely used in the treatment of brain tumors. Herein, the protective role of Codiaeum variegatum leaves ethyl acetate fraction was determined against genotoxicity of Cr. The technique HPLC-qTOF-MS/MS was used to identify the constituents in C. variegatum.

Materials

90 male mice were used to evaluate micronuclei (MPCEs) in bone marrow, chromosomal aberration (CAs) in bone marrow and mouse spermatocytes, sperm abnormalities, and gene expression (qRT-PCR). The following groups were included, I: Negative control (ethanol 30%), II: Positive control (i.p injected once with 30 mg/kg Cr), III: Control orally treated with C. variegatum at 500 mg/kg, four days. IV-VI: treated with 100, 300, and 500 mg/kg of the plant (4 days) plus a single dose of Cr.

Results

In bone marrow, Cr induced significant increase in MPCEs and CAs by 3 and 7-folds respectively over the control. Cr also induced a significant percentage of CAs in spermatocytes in meiosis in the form of univalent (X–Y and autosomal univalent) and also a significant percentage of morphological sperm abnormalities was recorded. A large number of coiled tail abnormalities were detected indicating the effect of Cr in sperm motility. Cr induced an overexpression of p53 gene. C. variegatum mitigated all deleterious genotoxic effects of Cr. Chemical analysis showed that flavones (35.21%) and phenolic acids (17.62%) constitute the main components.

Conclusions

The results indicated that Cr is genotoxic in both somatic and germ cells. The active components in C. variegatum together participate in the obtained protective role.

Protective role of the dried white mulberry extract on the reproductive damage and fertility in rats treated with carmustine

The present study investigated the protective effect of dried white Mulberry extract (DWME) against carmustine (Crm) induced biochemical alterations and spermatological, histopathological, and fertility damage in Wistar albino rats. Male rats were divided into four groups (control, Crm, Crm + DWME, and DWME group). It was found that Crm decreased the motility. Crm decreased the concentration (not different from control group) compared to DWME groups. Total blood MDA levels were reduced during the recovery period. Also, the recovery period reduced the MDA levels in the Crm group/testicular tissue. The GSH levels in the Crm + DWME group were the highest among all groups in the testicular tissue/experiment period. In the immunohistochemical evaluation of the testicular tissue, a high level of caspase-3 was observed in the cells that underwent meiosis in the Crm group. The most pronounced DNA damage was also detected in the Crm group. The Crm + DWME group showed the highest number of offspring born during recovery period. In conclusion, dried white mulberry extract protects against the spermatological damages caused by carmustine. Moreover, recovery period played a positive effect on spermatological parameters and fertility.

Physiological role of reactive oxygen species in testis and epididymal spermatozoa

The reactive oxygen species (ROS) play an important role in various aspects of male reproductive function, for spermatozoa to acquire the ability to fertilize. However, the increase in ROS generation, both due to internal and external factors, can induce oxidative stress, causing alterations in the structure and function of phospholipids and proteins. In the nucleus, ROS attack DNA, causing its fragmentation and activation of apoptosis, thus altering gene and protein expression. Accumulating evidence also reveals that endogenously produced ROS can act as second messengers in regulating cell signalling pathways and in the transduction of signals that are responsible for regulating spermatogonia self-renewal and proliferation. In the epididymis, they actively participate in the formation of disulphide bridges required for the final condensation of chromatin, as well as in the phosphorylation and dephosphorylation of proteins contained in the fibrous sheath of the flagellum, stimulating the activation of progressive motility in epididymal spermatozoa. In this review, the role of small amounts of ROS during spermatogenesis and epididymal sperm maturation was discussed.

Mitigation of cisplatin induced nephrotoxicity by casticin in male albino rats

Cisplatin (CP) is a commonly used, powerful antineoplastic drug, having numerous side effects. Casticin (CAS) is considered as a free radical scavenger and a potent antioxidant. The present research was planned to assess the curative potential of CAS on CP persuaded renal injury in male albino rats. Twenty four male albino rats were distributed into four equal groups. Group-1 was considered as a control group. Animals of Group-2 were injected with 5mg/kg of CP intraperitoneally. Group-3 was co-treated with CAS (50mg/kg) orally and injection of CP (5mg/kg). Group-4 was treated with CAS (50mg/kg) orally throughout the experiment. CP administration substantially reduced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione S-transferase (GST), glutathione reductase (GSR), glutathione (GSH) content while increased thiobarbituric acid reactive substances (TBARS), and hydrogen peroxide (H2O2) levels. Urea, urinary creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, albumin and creatinine clearance was significantly reduced in CP treated group. The results demonstrated that CP significantly increased the inflammation indicators including nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activity and histopathological damages. However, the administration of CAS displayed a palliative effect against CP-generated renal toxicity and recovered all parameters by bringing them to a normal level. These results revealed that the CAS is an effective compound having the curative potential to counter the CP-induced renal damage.

Toxicological effects of thimerosal on rat kidney: a histological and biochemical study

Thimerosal is an organomercurial compound, which is used in the preparation of intramuscular immunoglobulin, antivenoms, tattoo inks, skin test antigens, nasal products, ophthalmic drops, and vaccines as a preservative. In most of animal species and humans, the kidney is one of the main sites for mercurial compounds deposition and target organs for toxicity. So, the current research was intended to assess the thimerosal induced nephrotoxicity in male rats. Twenty-four adult male albino rats were categorized into four groups. The first group was a control group. Rats of Group-II, Group-III, and Group-IV were administered with 0.5µg/kg, 10µg/kg, and 50µg/kg of thimerosal once a day, respectively. Thimerosal administration significantly decreased the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), glutathione reductase (GR), glutathione (GSH), and protein content while increased the thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) levels dose-dependently. Blood urea nitrogen (BUN), creatinine, urobilinogen, urinary proteins, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) levels were substantially increased. In contrast, urinary albumin and creatinine clearance was reduced dose-dependently in thimerosal treated groups. The results demonstrated that thimerosal significantly increased the inflammation indicators including nuclear factor kappaB (NF-κB), tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), Interleukin-6 (IL-6) levels and cyclooxygenase-2 (COX-2) activities, DNA and histopathological damages dose-dependently. So, the present findings ascertained that thimerosal exerted nephrotoxicity in male albino rats.

Morphometric analysis and redox state of the testicles in nandrolone decanoate and swimming treated adult male rats

Background

During the last decades, the abuse of anabolic androgenic steroids (AASs) has become popular among professional and recreational athletes. The abuse of AASs leads to decreased levels of sex hormones, but the available literature a gives very small pool of data regarding the effects of swimming alone or combined with AASs on testicle tissue. The aim of this study was to investigate the effects of four-week administration of nandrolone decanoate and swimming training alone or in combination on morphometric parameters, androgen receptor (AR) and redox state in testicle tissue. The study included Wistar albino male rats, 10 weeks old, classified into 4 groups: control (T-N-), nandrolone (T-N+), swimming training (T+N-) and swimming training with nandrolone (T+N+). The rats from nandrolone (N+) groups received nandrolone decanoate 20 mg/kg b.w.once per week. The rats from training (T+) groups, swam 1 h/day 5 days/week. The isolated testicles were measured, left testicles were routinely processed for histological analysis, while right testicles were homogenized and prepared for the analysis of the following oxidative stress biomarkers: index of lipid peroxidation (TBARS), nitrites, catalase, superoxide dismutase (SOD), and reduced glutathione (GSH).

Results

Diameter, as well as cross-section area of seminiferous tubules were decreased by 10 % and 21 % (respectively) in the T-N+ group and by 15% and 41 % (respectively) in the T+N+ group compared to control. Interstitium of the testicles was decreased in all experimental groups. Reduction of immunoreactivity of AR in T-N+ group was 22 %, in T+N+ group was 9 % compared to control. TBARS levels were increased in T+N- and T+N+ groups. Nitrites were decreased in T+N+ group. Catalase activity was increased in all experimental groups. Swimming alone or combined with nandrolone decreased the level of GSH compared to control. SOD activity was decreased in T-N+ and T+N+ groups compared to control.

Conclusions

Nandrolone alone or combined with swimming decreased morphometric parameters and amount of AR in testicle tissue. Changes in the redox state indicate reproductive dysfunction.

Acetyl-11-keto-β-boswellic acid prevents testicular torsion/detorsion injury in rats by modulating 5-LOX/LTB4 and p38-MAPK/JNK/Bax/Caspase-3 pathways

AIMS

Testicular torsion/detorsion (T/D) is a critical medical condition that necessitates prompt surgical intervention to avoid testicular atrophy and infertility. The use of natural compounds may protect against the associated detrimental oxidative stress and inflammatory responses. Interestingly, acetyl-11-keto-β-boswellic acid (AKBA), the main active constituent of Boswellia resin, has shown potent inhibitory effect on 5-lipoxygenase enzyme which converts arachidonic acid into inflammatory mediators. Therefore, this study was conducted to assess the protective mechanisms by which AKBA may protect against testicular T/D injury in rats.

MAIN METHODS

Male rats were randomly distributed into five groups: Sham, AKBA (50 mg/kg, p.o.), unilateral testicular T/D, AKBA at two dose levels (25 or 50 mg/kg for 15 successive days) followed by T/D. Histological examination and Johnsen's score were performed to assess testicular injury and perturbations in spermatogenesis. Biochemical parameters included markers of testicular function (serum testosterone), oxidant/antioxidant status (malondialdehyde, glutathione), inflammation (5-lipoxygenase, leukotriene-B4, myeloperoxidase, interleukin-1β, interleukin-6), apoptosis (Bax, Bcl2, caspase-3), DNA integrity (quantitative DNA fragmentation, DNA laddering, PARP-1), energy production (ATP), in addition to p38 MAPK and JNK protein expression.

KEY FINDINGS

In a dose dependent manner, AKBA significantly inhibited testicular T/D-induced upregulation of 5-LOX/LTB4 and p38-MAPK/JNK/Bax pathways and their associated downstream inflammatory and apoptotic cascades. These effects were accompanied with ATP replenishment and DNA preservation, resulting ultimately in salvage of the testis.

SIGNIFICANCE

Unprecedentedly, the present mechanistic study revealed the pathways by which AKBA may inhibit testicular T/D injury and offered a novel protective approach that may attenuate the severity of this condition.

Assessing the effect of MitoQ10 and Vitamin D3 on ovarian oxidative stress, steroidogenesis and histomorphology in DHEA induced PCOS mouse model

Polycystic ovary syndrome (PCOS) continues to be one of the most complex reproductive and endocrine disorder among women of reproductive age. Recent reports have identified close interaction of Vitamin D deficiency and oxidative stress (OS) in exacerbating the pathophysiology of PCOS. This current study aims at assessing the combine effect of MitoQ₁₀ and Vitamin D3 on dehydroepiandrosterone (DHEA) induced PCOS. Following successful induction of PCOS using DHEA, mice were organized into five groups (n = 8) namely: Negative Control (NC), Vitamin D3 Vehicle (VDV), Vitamin D3 (VD), MitoQ₁₀ (MQ), Vitamin D3 plus MitoQ₁₀ (V+M) and DHEA, ethanol and distilled water, Vitamin D3, MitoQ₁₀ and Vitamin D3 plus MitoQ₁₀ were respectively administered for 20 consecutive days. The study also included positive control (PC) group (n = 8) in which no treatment was applied. Treatment effects were assessed using hormonal assays, biochemical assays, Real-Time PCR, western blotting and histological analysis. Combination of Vitamin D3 and MitoQ₁₀ significantly reduced levels of estradiol, progesterone, FSH, LH, LH/FSH, SOD and MDA. The expression rate of mRNAs of 3β-HSD, Cyp19a1, Cyp11a1, StAR, Keap1, HO-1 and Nrf2 were also significantly low in V+M group. Moreover, the histomorphological inspection of ovaries from this group revealed many healthy follicles at various stages of development including few atretic follicles, pre-antral and antral follicles and many corpora lutea. The characteristics observed in this group were in many ways similar to that of the PC group. The combination of MitoQ₁₀ and Vitamin D3 may be potential candidate to ameliorate PCOS.

Impact of thermal stress exposure on seminal quality, antioxidant defence system, TNF-α and TIMP-3 in Ossimi ram

Heat stress (HS) occupies huge importance nowadays as it leads to severe economic losses especially in livestock. Preserving sheep against HS is one of the governmental scopes where it represents huge percentage of global ruminant. The present research was conducted to study semen quality, some stress and inflammatory markers in Ossimi rams under both hot and mild climatic conditions. The current study was conducted on selected 46 ram samples divided into two groups during summer and winter. Semen analysis, testosterone (TES), cortisol (COR) and blood glucose (BG) levels, and lipid and protein profiles were done. Concentrations of tumour necrosis factor alpha (TNF-α), tissue inhibitor of metalloproteinase-3 (TIMP-3), nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) and specific activity of glutathione peroxidase (GPx) and superoxide dismutase (SOD) were assessed. The results in summer compared to winter revealed significant elevation of total defects and number of dead sperms; however, there was reduction in sperm total motility and concentration and external epididymal tail duct diameter. Histological study of epididymal tail lumen exhibited azoospermia. Further, TES, TIMP-3 and GSH levels were decreased and COR, TNF-α, NO and MDA were raised. Specific activities of GPx and SOD were also declined. Additionally, there was a significant increase in concentrations of BG and lipid profiles except high-density lipoprotein. Our data concluded that there were new insights into TNF-α and TIMP-3 as biomarkers can be used in diagnosis of sheep suffering from HS, but further studies are recommended to do in future work about such aspect.

Taurine and hesperidin rescues carbon tetrachloride-triggered testicular and kidney damage in rats via modulating oxidative stress and inflammation

AIMS

This study assessed the prophylactic or therapeutic effects of taurine (TR) and/or hesperidin (HES) on carbon tetrachloride (CCl₄) induced acute kidney and testicular injury in rats.

MAIN METHODS

Rats were randomly divided into nine experimental groups including control; corn oil; CCl₄; HES/CCl₄; TR/CCl₄; HES + TR/CCl₄; CCl₄/HES; CCl₄/TR; and CCl₄/HES + TR groups. CCl₄ was intraperitoneally injected with a single dose of 2 ml /kg b.w. HES and TR were orally gavaged twice weekly 100 mg/kg b.w. for four weeks. Kidney function, inflammatory response, sexual hormones, and oxidative stress indicators were assessed. Histomorphological and immune-histochemical studies of the inflammatory marker nuclear factor kappa (NF-κB) in renal and testicular tissues were performed.

KEY FINDINGS

The results showed that the TR and/or HES treatment significantly suppressed CCl₄ induced rise of urea, uric acid, potassium, and follicle-stimulating hormone levels. However, significant restoration of sodium, testosterone, and luteinizing hormone was apparent in CCl₄ exposed rats received HES and/or TR. Also, the HES and/or TR treatment significantly rescues CCl₄ induced oxidative stress and inflammation. Moreover, the HES and/or TR dosing significantly repaired the CCl₄ evoked altered renal and testicular architecture and suppressed NF-κB immunoexpression. Notably, alleviating CCl₄ induced renal and testicular damage was more effective in the prophylactic groups than the therapeutic groups. Also, most of the estimated parameters of the HES + TR group did not significantly vary from those of single TR or HES.

SIGNIFICANCE

In conclusion, HES or TR could efficiently guard against CCl₄ nephro-and reprotoxic effects, but both bioactive combinations afford only a limited synergistic outcome.

Dietary Micronutrient Supplementation for 12 Days in Obese Male Mice Restores Sperm Oxidative Stress

Male obesity, which often co-presents with micronutrient deficiencies, is associated with sub-fertility. Here we investigate whether short-term dietary supplementation of micronutrients (zinc, selenium, lycopene, vitamins E and C, folic acid, and green tea extract) to obese mice for 12 days (designed to span the epididymal transit) could improve sperm quality and fetal outcomes. Five-week-old C57BL6 males were fed a control diet (CD, n = 24) or high fat diet (HFD, n = 24) for 10 weeks before allocation to the 12-day intervention of maintaining their original diets (CD, n = 12, HFD n = 12) or with micronutrient supplementation (CD + S, n = 12, HFD + S, n = 12). Measures of sperm quality (motility, morphology, capacitation, binding), sperm oxidative stress (DCFDA, MSR, and 8OHdG), early embryo development (2-cell cleavage, 8OHdG), and fetal outcomes were assessed. HFD + S males had reduced sperm intracellular reactive oxygen species (ROS) concentrations and 8OHdG lesions, which resulted in reduced 8OHdG lesions in the male pronucleus, increased 2-cell cleavage rates, and partial restoration of fetal weight similar to controls. Sub-fertility associated with male obesity may be restored with very short-term micronutrient supplementation that targets the timing of the transit of sperm through the epididymis, which is the developmental window where sperm are the most susceptible to oxidative damage.

Testicular toxicity of gentamicin in adult rats: Ameliorative effect of lycopene

The current study was aimed to investigate the ameliorative effect of lycopene against gentamicin-induced testicular toxicity in adult rat testes. Pretreatment with lycopene (4 mg/kg/day) significantly prevented the decrease in the absolute testes weight and relative testes weight and the reduction in sperm count, motility, viability, and daily sperm production in gentamicin (100 mg/kg/day)-treated rats. Gentamicin significantly decreased the level of serum testosterone and testicular lactate dehydrogenase-X and G6PDH activities but a marked increase was observed upon pretreatment with lycopene. Testicular caspase-3 and -9 activities were significantly increased but lycopene showed significant protection from gentamicin-induced apoptosis. Oxidative stress was induced by gentamicin treatment as evidenced by increased hydrogen peroxide level and lipid peroxidation and decreased the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities and glutathione content. These alterations were effectively prevented by lycopene pretreatment. Histopathological examination showed loss of spermatogenesis and morphological abnormalities of the testis after treatment with gentamycin. These abnormalities were effectively normalized by pretreatment with lycopene. In conclusion, gentamicin decreases rat testes weight and inhibits spermatogenesis. It induces oxidative stress and apoptosis by possible mitochondrial dysfunction. These data provide insight into the mode of action of gentamicin-induced testicular toxicity and the beneficial role provided by lycopene to restore the suppressed spermatogenesis.

MitoQ ameliorates testicular damage induced by gamma irradiation in rats: Modulation of mitochondrial apoptosis and steroidogenesis

AIMS

The deleterious effect of gamma radiation on testicular tissue is a challenging problem in nuclear medicine. This study investigated the potential radioprotective effect of mitoquinol (MitoQ), a mitochondria-targeted antioxidant, against testicular damage induced by gamma irradiation in rats.

MAIN METHODS

Rats were allocated into four groups. The first group served as the control, the second group received MitoQ (2 mg / kg / day; i.p.) for seven days, the third group was exposed to gamma radiation (5 Gy as a single dose) and the last group received MitoQ prior to irradiation. Rats were sacrificed. Then, sperm analyses and the serum testosterone were determined. Moreover, evaluation of mitochondrial oxidative stress parameters (SOD, GSH and GPx) as well as apoptosis indicators (cytochrome-c, Bax, Bcl-2 and caspase-3) was performed. Additionally, analysis of steroidogensis biomarkers (StAR, 3β-HSD and 17β-HSD) and histopathological investigations were carried out.

KEY FINDINGS

MitoQ replenished mitochondrial SOD, GPx and GSH indicating its strong antioxidant effect in addition to its energy preservation manifested by the elevated ATP. MitoQ inhibited the intrinsic apoptosis via diminution of Bax, cytochrome-c and caspase-3 and alleviation of Bcl-2. This antioxidant conferred protection to steroidogenesis as verified by the increase in testosterone and the up-regulation of StAR, 3β-HSD and 17β-HSD expression; these effects might be correlated with its antioxidant/anti-apoptotic potential. Histopathological and sperm analyses corroborated the biochemical findings.

SIGNIFICANCE

This study identifies MitoQ as a novel agent for the management of testicular toxicity induced by gamma irradiation.

Antioxidant enzyme expression of mRNA and protein in the epididymis of finasteride-treated male rat offspring during postnatal development

INTRODUCTION

We verify whether finasteride had a transgenerational effect on the epididymal expression of antioxidant enzymes, and the correlation between these enzymes and blood androgen concentrations in male offspring (F1:Fin) of females fertilized by finasteride-treated male rats.

MATERIAL AND METHODS

The expression of CAT, SOD1, GPX5, GR on the mRNA and protein levels was evaluated in the epididymis at postnatal day (PND) 7, 14, 21, 28 and 90. Levels of T and DHT were correlated with mRNA levels of enzymes by Spearman's rank correlation coefficient.

RESULTS

A change in the levels of transcripts was noted in F1:Fin rats: CAT decreased at PND 28 (p < 0.01) and increased at PND 90 (p < 0.01); SOD1 increased at PND 7 (p < 0.0001), 21 (p < 0.001), 90 (p < 0.0001) and decreased at 14 PND (p < 0.01); GPX5 increased at PND 14 and 21 (p < 0.0001); GR decreased at PND 21 and 28 (p < 0.0001). Altered immunolocalization of enzymes within the epididymal epithelium was observed. Negative correlations between GPX5 mRNA with androgens (T, p = 0.0002; DHT, p = 0.0009) were visible in the control rats, and positive correlation between DHT and CAT mRNA (p = 0.03), in opposite to F1:Fin group were was negative for both androgens (T, p = 0.044 and DHT, p = 0.02).

CONCLUSIONS

Finasteride treatment of adult male rats may cause changes in antioxidant defense system in the epididymis of their offspring, leading to improper ROS concentrations that can affect post-testicular sperm maturation.

In vitro study of doxorubicin-induced oxidative stress in spermatogonia and immature Sertoli cells

Pediatric chemotherapy treatments can impair long-term male fertility. Unfortunately, no fertility preservation solution is available for pre-pubertal boys. Studies suggest that doxorubicin, used against pediatric cancers, induces oxidative stress in the testis. However, the targeted testicular cell types remain unknown. The goal of this study was to determine whether doxorubicin can induce oxidative stress in rat spermatogonia (GC-6Spg) and immature Sertoli (Ser-W3) cell lines, and to assess their protection by antioxidants. Using the MTT assay, we have shown that doxorubicin induces a time- and dose-dependent cytotoxicity in these two cell lines, Ser-W3 being more sensitive than GC-6Spg. After 3 h of treatment, reactive oxygen species and nuclear 8-oxo-deoxyguanosine increase in Ser-W3, but not in GC-6Spg. Moreover, after 6 h of treatment, intracellular reduced glutathione levels decrease significantly in Ser-W3 cells. These results show that doxorubicin induces oxidative stress in the Ser-W3 cell line. However, a depletion in glutathione does not affect their survival, and supplementation only offers a weak protection after exposure to doxorubicin, suggesting that the glutathione system is not essential for Ser-W3 cell line's defense against doxorubicin. On the other hand, among four antioxidants selected from the literature, none reduces the cytotoxicity of doxorubicin in Ser-W3 cells. Together, our data suggest that oxidative stress may not be a major pathway for doxorubicin's cytotoxicity in GC-6Spg and Ser-W3 lines. This study provides new insights in the mechanisms by which chemotherapies affect the pre-pubertal testis, with the long-term goal to help improve the quality of life of pediatric cancer survivors.

p,p'-DDT induces testicular oxidative stress-induced apoptosis in adult rats

BACKGROUND

The 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDT) is a known persistent organic pollutant and male reproductive toxicant. The present study is designed to test the hypothesis that oxidative stress mediates p,p'-DDT-induced apoptosis in testis.

METHODS

Male Wistar rats received an intraperitoneal (ip) injection of the pesticide at doses of 50 and 100mg/kg for 10 consecutive days. The oxidative stress was evaluated by biomarkers such lipid peroxidation (LPO) and metallothioneins (MTs) levels. Antioxidant enzymes activities was assessed by determination of superoxide dismutase (SOD), catalase (CAT) and hydrogen peroxide (H₂O₂) production. In addition, glutathione-dependent enzymes and reducing power in testis was evaluated by glutathione peroxidase (Gpx), glutathione reductase (GR), glutathione S-transferase (GST) activities and reduced and oxidized glutathione (GSH - GSSG) levels. Apoptosis was evaluated by DNA fragmentation detected by agarose gel electrophoresis. Germinal cells apoptosis and the apoptotic index was assessed through the TUNEL assay.

RESULTS

After 10 days of treatment, an increase in LPO level and H₂O₂ production occurred, while MTs level, SOD and CAT activities were decreased. Also, the Gpx, GR, GST, and GSH activities were decreased, whereas GSSG activity was increased. Testicular tissues of treated rats showed pronounced degradation of the DNA into oligonucleotides as seen in the typical electrophoretic DNA ladder pattern. Intense apoptosis was observed in germinal cells of DDT-exposed rats. In addition, the apoptotic index was significantly increased in testis of DDT-treated rats.

CONCLUSIONS

These results clearly suggest that DDT sub-acute treatment causes oxidative stress in rat testis leading to apoptosis.

Lipoic acid and Calligonum comosumon attenuate aroclor 1260-induced testicular toxicity in adult rats

Aroclor 1260 is one of the more representative polychlorinated biphenyls found in biota. This study was designed to delineate the testicular toxicity of Aroclor 1260 and to elucidate the potential protective role of Calligonum comosum (C. comosum) and lipoic acid in adult rats. Aroclor 1260 was dissolved in corn oil and given to rats by gavage at doses 0, 20, 40, or 60 mg/kg/day for 15 consecutive days (Groups I, II, III, and IV, respectively). Groups V and VI were pretreated with C. comosum (200 mg/kg/day) and lipoic acid (35 mg/kg/day) respectively 24 h before Aroclor 1260 (40 mg/kg/day) treatment for 15 consecutive days. Aroclor 1260 (20, 40 or 60 mg/kg/day) treatment significantly decreased testes weight, sperm count and motility and daily sperm production. Serum testosterone was significantly decreased in response to treatment with 40 and 60 mg/kg/day of Aroclor 1260. LDH-X activity was significantly decreased at the three dose levels. Hydrogen peroxide (H₂ O₂ ) production (in a dose-related manner) and lipid peroxidation were significantly increased in response to Aroclor 1260 (20, 40, or 60 mg/kg/day) treatment. Aroclor 1260 at the three dose levels decreased the activities of the antioxidant enzymes SOD, CAT, GPx, and GR and the non-enzymatic antioxidant GSH level. CAT, GPx and GSH showed a dose-response effect. These abnormalities were effectively attenuated by pretreatment with C. comosum (200 mg/kg/day) or lipoic acid (35 mg/kg/day). Histopathological examination showed a dose-related increase in morphological abnormalities of the testis in response to Aroclor 1260 treatment. In conclusion, Aroclor 1260 induced testicular toxicity at least, in part, by induction of oxidative stress. By reversal of biochemical and morphological changes towards normalcy, the cytoprotective role of C. comosum and lipoic acid is illuminated. In comparison, lipoic acid was more protective than C. comosum extract against testicular toxicity induced by Aroclor 1260. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1147-1157, 2017.

Repeated administration of ethambutol in therapeutic dose causes testes alteration and spermatogenesis disruption in Wistar rats

Ethambutol (EMB) is conventionally used to treat tuberculosis and atypical Mycobacterium infections in combination with other antimycobacterial drugs. Eventually, EMB testicular toxicity has not been explored extensively yet. The aim of the study is to evaluate testicular toxicity of EMB. We explored the impact of EMB on male rats' fertility, testosterone level and germ cells state, testicular pro- and anti-oxidant status and DNA damage, as well as identified EMB effects on cytochrome P-450 2E1 (CYP2E1) both with computer simulation and in vivo. We demonstrated that EMB administration to male rats decreased in epididymal sperm count (19%) and fertility index (53%). These events were accompanied by reduction in serum testosterone content (1.6 times) and appearance of spermatogenic epithelium damages. It was also found in testes the intensification of lipid peroxidation, decrease in reduced glutathione content and changes in DNA fragmentation. Additionally, computer simulation showed direct interaction of EMB with CYP2E1 active site and heme. On the top of this, we demonstrated that level of testicular CYP2E1 messenger RNA in EMB-treated rats was increased 8.7 folds and p-nitrophenol hydroxylase activity in testes rose three folds. As this shows, EMB-caused CYP2E1 induction, oxidative stress, and apoptosis in the testes contribute to inhibition of steroidogenesis enzymes and spermatogenesis disruption.

Does Ataxia Telangiectasia Mutated (ATM) protect testicular and germ cell DNA integrity by regulating the redox status?

A balanced redox homeostasis in the testis is essential for genetic integrity of sperm. Reactive oxygen species can disturb this balance by oxidation of glutathione, which is regenerated using NADPH, formed by glucose-6-phosphate dehydrogenase (G6PDH). G6PDH is regulated by the Ataxia Telangiectasia Mutated (Atm) protein. Therefore, we studied the redox status and DNA damage in testes and sperm of mice that carried a deletion in Atm. The redox status in heterozygote mice, reflected by glutathione levels and antioxidant capacity, was lower than in wild type mice, and in homozygotes the redox status was even lower. The redox status correlated with oxidative DNA damage that was highest in mice that carried Atm deletions. Surprisingly, G6PDH activity was highest in homozygotes carrying the deletion. These data indicate that defective Atm reduces the redox homeostasis of the testis and genetic integrity of sperm by regulating glutathione levels independently from G6PDH activity.

Glutathione and its related enzymes in the gonad of Nile Tilapia (Oreochromis niloticus)

Glutathione (GSH) concentration, the activity of its metabolizing enzymes, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and the antioxidant enzyme catalase (CAT) in O. niloticus ovary and testis were examined. GSH concentration of O. niloticus testis exhibited high concentration (129 ± 21 nmol/g tissue) compared with GSH concentration (49.2 ± 8.3 nmol/g tissue) in the ovary. GST, GPx, GR, and CAT activities of O. niloticus testis exhibited high values compared with their corresponding values in ovary homogenates. However, protein concentration in ovary homogenates exhibited higher values (175 ± 40.6 mg) compared with testis homogenates (27.1 ± 3.7 mg). O. niloticus ovary was less effective in excretion of xenobiotices compared with the testis, where its function is mainly in increasing the protein content of the eggs; however, in O. niloticus testis, the glutathione cycle operated in accelerated way in the direction of reduced GSH production in order to protect the maturation stages in a save way. A simple reproducible procedure for the purification of GST from O. niloticus ovary was established. The enzymes proved to be homogenous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its molecular weight was calculated to be 25.1 kDa. GST of O. niloticus ovary exhibited maximum activity at pH 7.5. The Michaelis-Menten constant (K(m)) of the purified ovary GST for GSH and CDNB was 0.076 mM and 1.0 mM, respectively. Cibacron blue was the most potent inhibitor of ovary GST activity (IC50 value, concentration of inhibitor that will give 50% inhibition, equal 0.002 μM). The specific activity of GST toward different electrophilic substrates was determined. GST activity toward benzyl isothiocyanate was the highest compared with phenethyl isothiocyanate and allyl isothiocyanate.

Design and Synthesis of N-Arylphthalimides as Inhibitors of Glucocorticoid-Induced TNF Receptor-Related Protein, Proinflammatory Mediators, and Cytokines in Carrageenan-Induced Lung Inflammation

N-Arylphthalimides (1-10P) derived from thalidomide by insertion of hydrophobic groups were evaluated for anti-inflammatory activity, and (4-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-N'-[(4-ethoxyphenyl)methylidene]benzohydrazide 6P was identified as a promising anti-inflammatory agent. Further testing confirmed that compared with the control, 6P treatment resulted in a considerable decrease in CD4(+), NF-κB p65(+), TNF-α(+), IL-6(+), GITR(+), and IL-17(+) cell populations and an increase in the Foxp3(+), CD4(+)Foxp3(+), and IκBα(+) populations in whole blood and pleural fluid of a mouse model of lung inflammation. Moreover, treatment with compound 6P decreased the proteins associated with inflammation including TNF-α, IL-6, IL-17, GITR, NF-κB, COX-2, STAT-3, and iNOS and increased the anti-inflammatory mediators such as IL-10 and IL-4. Further, histopathological examination confirmed the potent anti-inflammatory effects of compound 6P. Thus, the N-arylphthalimide derivative 6P acts as a potent anti-inflammatory agent in the carrageenan-induced lung inflammation model, suggesting that this compound may be useful for the treatment of inflammation in a clinical setting.

Amelioration of nandrolone decanoate-induced testicular and sperm toxicity in rats by taurine: effects on steroidogenesis, redox and inflammatory cascades, and intrinsic apoptotic pathway

The wide abuse of the anabolic steroid nandrolone decanoate by athletes and adolescents for enhancement of sporting performance and physical appearance may be associated with testicular toxicity and infertility. On the other hand, taurine; a free β-amino acid with remarkable antioxidant activity, is used in taurine-enriched beverages to boost the muscular power of athletes. Therefore, the purpose of this study was to investigate the mechanisms of the possible protective effects of taurine on nandrolone decanoate-induced testicular and sperm toxicity in rats. To achieve this aim, male Wistar rats were randomly distributed into four groups and administered either vehicle, nandrolone decanoate (10mg/kg/week, I.M.), taurine (100mg/kg/day, p.o.) or combination of taurine and nandrolone decanoate, for 8 successive weeks. Results of the present study showed that taurine reversed nandrolone decanoate-induced perturbations in sperm characteristics, normalized serum testosterone level, and restored the activities of the key steroidogenic enzymes; 3β-HSD, and 17β-HSD. Moreover, taurine prevented nandrolone decanoate-induced testicular toxicity and DNA damage by virtue of its antioxidant, anti-inflammatory, and anti-apoptotic effects. This was evidenced by taurine-induced modulation of testicular LDH-x activity, redox markers (MDA, NO, GSH contents, and SOD activity), inflammatory indices (TNF-α, ICAM-1 levels, and MMP-9 gene expression), intrinsic apoptotic pathway (cytochrome c gene expression and caspase-3 content), and oxidative DNA damage markers (8-OHdG level and comet assay). In conclusion, at the biochemical and histological levels, taurine attenuated nandrolone decanoate-induced poor sperm quality and testicular toxicity in rats.

The effect of etoricoxib, a cyclooxygenase-2-specific inhibitor, on the 1,2-dimethylhydrazine-administered rat intestinal membrane structure and function

ABSTRACT To gain insight into the chemopreventive effects of etoricoxib, which is a selective inhibitor of cycloxygenase-2, a study was carried out in the procarcinogen 1,2-dimethylhydrazine-treated rat intestine. The male Sprague Dawley rats were divided into three different groups. Group 1 served as control (vehicle treated). All animals in Group 2 were given a weekly subcutaneous injection of 1,2-dimethylhydrazine (DMH; 30 mg/kg body weight) for 6 weeks. Group 3 animals were given an additional oral dose of etoricoxib (6 mg/kg body weight) along with weekly DMH injections for 6 weeks. At the end of 6 weeks of treatments, the results indicated significant alterations in the biochemical parameters, membrane lipid composition, and membrane fluorescence studies of the intestine in the presence of DMH, which were recovered nearly to the control level and, therefore, may suggest the chemopreventive efficacy of etoricoxib against the experimental intestinal cancer in rats.

Increased sensitivity to testicular toxicity of transplacental benzo[a]pyrene exposure in male glutamate cysteine ligase modifier subunit knockout (Gclm-/-) mice

Polycyclic aromatic hydrocarbons (PAHs), like benzo[a]pyrene (BaP), are ubiquitous environmental pollutants formed by the incomplete combustion of organic materials. The tripeptide glutathione (GSH) is a major antioxidant and is important in detoxification of PAH metabolites. Mice null for the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in GSH synthesis, have decreased GSH concentrations. We investigated the effects of Gclm deletion alone on male fertility and spermatogenesis and its effect on the sensitivity of male embryos to the transplacental testicular toxicity of BaP. Gclm-/- males had dramatically decreased testicular and epididymal GCL enzymatic activity and total GSH concentrations compared with Gclm+/+ littermates. Ratios of reduced to oxidized GSH were significantly increased in Gclm-/- testes. GSH reductase enzymatic activity was increased in Gclm-/- epididymides. We observed no changes in fertility, testicular weights, testicular sperm head counts, or testicular histology and subtle changes in cauda epididymal sperm counts, motility, and morphology in Gclm-/- compared with Gclm+/+ males. Prenatal exposure to BaP from gestational day 7 to 16 was dose dependently associated with significantly decreased testicular and epididymal weights, testicular and epididymal sperm counts, and with vacuolated seminiferous tubules at 10 weeks of age. Gclm-/- males exposed prenatally to BaP had greater decreases in testicular weights, testicular sperm head counts, epididymal sperm counts, and epididymal sperm motility than Gclm+/+ littermates. These results show no effects of Gclm deletion alone on male fertility and testicular spermatogenesis and subtle epididymal effects but support increased sensitivity of Gclm-/- males to the transplacental testicular toxicity of BaP.

Unveiling the roles of the glutathione redox system in vivo by analyzing genetically modified mice

Redox status affects various cellular activities, such as proliferation, differentiation, and death. Recent studies suggest pivotal roles of reactive oxygen species not only in pathogenesis under oxidative insult but also in intracellular signal transduction. Glutathione is present in several millimolar concentrations in the cytoplasm and has multiple roles in the regulation of cellular homeostasis. Two enzymes, γ-glutamylcysteine synthetase and glutathione synthetase, constitute the de novo synthesis machinery, while glutathione reductase is involved in the recycling of oxidized glutathione. Multidrug resistant proteins and some other transporters are responsible for exporting oxidized glutathione, glutathione conjugates, and S-nitrosoglutathione. In addition to antioxidation, glutathione is more positively involved in cellular activity via its sulfhydryl moiety of a molecule. Animals in which genes responsible for glutathione metabolism are genetically modified can be used as beneficial and reliable models to elucidate roles of glutathione in vivo. This review article overviews recent progress in works related to genetically modified rodents and advances in the elucidation of glutathione-mediated reactions.

Bisphenol A effect on glutathione synthesis and recycling in testicular Sertoli cells

BACKGROUND AND OBJECTIVE

Controversial effects of bisphenol A (BPA) have been reported on testicular function. These differences might reflect dissimilar exposure conditions. Dose responses to toxicants may be non-linear, e.g. U-shaped, with effects at low and at high levels of exposure and lower or inexistent effects at intermediate levels. Sertoli cells produce high levels of glutathione (GSH) as a cell defense mechanism. In this study, we addressed the question whether the exposure to different doses of BPA could influence Sertoli cell GSH synthesis and recycling.

MATERIALS AND METHODS

Primary Sertoli cell cultures were exposed to various doses of BPA (0.5 nM-100 μM). Cell viability was measured as an outcome of toxic effect. GSH cell content was determined to evaluate cell response to toxicant exposure. Glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunit expression were assessed to estimate GSH synthesis, and GSH reductase (GR) expression to estimate GSH recycling.

RESULTS

BPA 100 μM, but not lower doses, decreased cell viability. BPA 10 and 50 μM, but not lower doses, induced an increment in Sertoli cell GSH levels, due to a rapid upregulation of GCLC and GR and a slower upregulation of GCLM.

CONCLUSIONS

High doses of BPA are deleterious for Sertoli cells. Intermediate doses do not affect Sertoli cell viability and increase cell content of GSH owing to increased GSH synthesis and recycling enzyme expression. Lower doses of BPA are not capable of eliciting a cell defense response. These observations may explain a non-linear dose response of Sertoli cells to BPA.

Toxic effects of T-2 toxin on reproductive system in male mice

The present study was conducted to evaluate the effects of T-2 toxin on semen quality, fertility and serum testosterone concentration in mice. Adult male mice were mated with sexually mature untreated female mice after being exposed to intraperitoneal injection of T-2 toxin at 0, 5, 10 or 15 mg/kg body weight daily for 7 successive days. Semen quality, serum testosterone concentration and fertility of treated mice were assessed. The results showed that the number of abnormal spermatozoa increased significantly and a significant decrease in spermatozoa with integrated acrosome was observed in males treated with T-2 toxin at all doses, As well, the amount of live spermatozoa decreased significantly in mice treated with 10 and 15 mg/kg body weight T-2 toxin. Low pregnancy rate and high fetal resorption rate were observed when females were mated with T-2 toxin—exposed males. Testicular and cauda epididymal sperm counts, efficiency of sperm production and serum testosterone concentration were significantly reduced in mice treated with T-2 toxin at all doses in a dose-dependent manner. In conclusion, these findings indicated that T-2 toxin presented toxic effects on reproductive system of adult male mice.

Raphanus sativus extract protects against Zearalenone induced reproductive toxicity, oxidative stress and mutagenic alterations in male Balb/c mice

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium in cereals and agricultural products. It has been implicated in several mycotoxicosis in farm animals and in humans. There is unequivocal evidence of reproductive toxicity of ZEN in male mice although the mechanism of action is unknown. Several reports suggest that exposure to ZEN resulted in oxidative stress, genotoxicity and perturbation of reproductive parameters. Therefore, the aim of the current study was to evaluate the protective effects of aqueous extract of Raphanus sativus growing in Tunisia against ZEN-induced reproductive toxicity and oxidative stress. Fifty male Balb/c mice were divided into five groups and treated for 28 days as follows: the control group, olive oil-treated groups, another treated with ZEN (40 mg/kg b.w), the last one treated with R. sativus extract alone (15 mg/kg b.w) and the other with ZEN + R. sativus extract. Testis samples were collected for the epididymal sperm count, testosterone concentration, and MDA level, GPx, CAT and SOD activities. Blood samples were collected for different biochemical analyses. Also, RAPD-PCR method was performed to assess the antigenotoxic effect of the extract in germ cells. The results indicated that ZEN-induced toxicological effects in accordance to those reported in the literature: decreasing in the sperm number, testosterone level and antioxidant enzyme status. The RAPD-PCR analysis revealed an alteration in the DNA bands patterns between control and ZEN-treated mice. The extract alone, rich in many antioxidant compounds, was safe and succeeded in counteracting the oxidative stress and protect against the toxicity resulting from ZEN.

Sulfasalazine induced oxidative stress: a possible mechanism of male infertility

The mechanism of action of sulfasalazine (SASP) in male infertility is not well elucidated. For it, an oxidative stress-like mechanism inductor of infertility was hypothesized. Adult male Sprague-Dawley rats (20/group) were orally administered 0, 300, and 600mg SASP/kg body weight for 14 days. One-half of animals in each group remained an additional period of 14 days without treatment. SASP induced a significant decrease of superoxide dismutase (SOD) and glutathione reductase (GR) at the highest dose in both testis and epididymis. GR remained altered in these tissues within the recovery period. However, an increase in SOD was noted in epididymis. An increase in thiobarbituric acid-reactive substances (TBARS) was noted in all SASP-treated groups. In epididymis, catalase (CAT) significantly increased at 600mg/(kgday). These results suggest that SASP induces oxidative stress, which in turn might act as a possible mechanism of male-induced infertility.

Effect of nonsteroidal anti-inflammatory drugs and the procarcinogen 1,2-dimethylhydrazine on the antioxidant defense system

The present study was designed to evaluate the effects of three nonsteroidal anti-inflammatory drugs (NSAIDs) with varying cycloxygenase selectivities on the small intestinal antioxidant enzyme status and surface characteristics during 1,2-dimethylhydrazine (DMH) administration. Male Sprague-Dawley rats were divided into five different groups: Group 1 (control, vehicle treated); group 2 (DMH treated, 30 mg/kg body weight/week, subcutaneously); group 3 (DMH + aspirin 60 mg/kg body weight); group 4 (DMH + celecoxib 6 mg/kg body weight); group 5 (DMH + etoricoxib 0.64 mg/kg body weight). Postmitochondrial fraction were isolated from the intestinal segments and different oxidative parameters and other parameters studied, such as the lipid peroxides, reduced and total glutathione, superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase, nitric oxide, citrulline, and nucleic acids. At the end of 6 weeks of treatment, the results indicated a significant alteration in the antioxidative defense status of the intestine in the presence of the procarcinogen DMH, which was restored with the administration of NSAIDs. The study, therefore, suggests a possible mechanism for the chemopreventive effects of NSAIDs against the experimental intestinal cancer in rats.

Oxidative effects of Na+--specific ionophore monensin on the rat epididymis

The carboxylic antibiotic ionophore monensin is well-known for the Na+/H+ exchanger activity across the biological membranes. The current study has been designed to investigate the effect of monensin on spermatozoal concentration, motility, and oxidative stress-related parameters in the rat epididymis. Monensin was administered orally at a dose of 3.5 mg/kg body weight daily for 70 days, a duration that coincides with the completion of the spermatogenic cycle. At the end of the respective treatment, the epididymis was isolated into three separate regions--the capitum, corpus, and the cauda--successively away from the head of the testis. Marked changes were noted in the body weight, organ (epididymis) weight, sperm concentration and motility, as well as the morphologic observations of the sperm and the histologic architecture of the epididymal epithelium. Significant alterations were also recorded in the oxidative stress parameters such as the lipid peroxidation product, malonyldialdehyde, and the activity of superoxide dismutase, glutathione sulfotransferase, glutathione reductase, and catalase. The nonenzymatic thiol content such as the total, oxidized, and reduced glutathione showed significant changes and the tissue phosphatases such as alkaline and acid phosphatase were increased, indicative of the interference of the drug in lysosomal and Golgi membrane complex. The findings of the current study indicate interactions during the spermatozoal maturational process in the epididymis, and a significant potential use of monensin in male contraception may be suggested.

FSH and bFGF stimulate the production of glutathione in cultured rat Sertoli cells

Migration of developing germ cells from the basal to the adluminal compartment of the seminiferous epithelium requires extensive tissue restructuring, resulting in the production of reactive oxygen species. Sertoli cells are involved in this process. Glutathione (GSH), produced by Sertoli cells, has an essential role in cell protection against oxidative stress. Intracellular GSH content is maintained by de novo synthesis, involving glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunits, and by recycling from oxidized GSH, catalysed by glutathione reductase (GR). To assess whether follicle-stimulating hormone (FSH) and basic fibroblast growth factor (bFGF) modulate GSH production in Sertoli cells by regulating the expression of GCLC, GCLM and/or GR, we performed in vitro studies using rat Sertoli cells in primary culture. FSH and bFGF stimulation increased Sertoli cell GSH levels after 24 h incubation. The simultaneous addition of FSH and bFGF did not produce any further effect. GCLM expression was upregulated by FSH and bFGF 6 h. At 24 h, only the FSH-mediated effect was still observed. FSH and bFGF also upregulated GR expression. In conclusion, our results show that FSH and bFGF increase GSH levels in Sertoli cells through stimulation of the de novo synthesis and recycling by upregulating GCLM and GR expression respectively. Therefore, protection of germ cells against oxidative stress seems to be regulated by hormones and germ cell-released growth factors capable of influencing the production of Sertoli cell GSH.

Effect of monensin on the enzymes of oxidative stress, thiamine pyrophosphatase and DNA integrity in rat testicular cells in vitro

Monensin, a sodium specific ionophore was evaluated for its in vitro effects on rat testis by studying changes at biochemical parameters as well as at the DNA level. It was observed that monensin produced marked alterations in the activities of various enzymes associated with the testicular functions. The significant inhibition of different enzymes of oxidative defense system points toward the generation of reactive oxygen species (ROS) by monensin treatment. The significant depletion of reduced glutathione and elevation in the level of lipid peroxidation further support the above findings. The significant inhibition of the activities of lactate dehydrogenase and adenosine triphosphatase shows the interference of monensin with the normal energy supply in spermatogenesis. Moreover, the significant increase in the activities of acid phosphatase and thiamine pyrophosphatase demonstrates the interference of monensin with the Golgi-lysosomal complex of the rat testis. Induced DNA fragmentation indicates towards the impact of monensin on the DNA integrity and apoptosis. Further studies are needed to understand the important molecular mechanisms responsible for these effects.

In vivo effects of BISGMA-a component of dental composite-on male mouse reproduction and fertility

The aim of this study is to investigate the effects of the resin monomer bisphenol A glycerolate dimethacrylate (BISGMA) on adult male mouse fertility. Male Swiss mice were administered various concentrations of BISGMA (0, 25, and 100 microg/kg) for a period of 28 days, and the effects on fertility was assessed by breeding these males with untreated female mice after the exposure periods. The results showed that fertility was significantly reduced when male mice were exposed to BISGMA, in comparison with their control counterparts. In females mated with males exposed to BISGMA, there was a significant reduction in the pregnancy rates as well as the number of viable fetuses. The number of resorptions out of the total number of implantations was significantly increased in females mated with males that had been exposed to BISGMA. Furthermore, the number of females with resorptions was also significantly increased. Significant reductions in bodyweight and weights of the testis and preputial glands were also observed. The weights of the seminal vesicles were significantly increased in males exposed to BISGMA in comparison with their control counterparts. There were significant reductions in testicular sperm counts, epididymal sperm counts and in the efficiency of sperm production. In conclusion, exposure of male mice to BISGMA results in an impairment of the reproductive system and fertility.

2-Acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylcarbonylamino)- phenylcarbamoylsulfanyl]propionic acid and its derivatives as a novel class of glutathione reductase inhibitors

Glutathione reductase (GR) catalyzes the reduction of oxidized glutathione to reduced glutathione. The enzyme is an attractive target for the development of antimalarial agents, agents to decrease malarial drug resistance and anticancer agents. In addition, inhibition of the enzyme has been employed as a tool in research for various purposes. In this paper, we present a rational design of 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylcarbonylamino)phenylcarbamoylsulfanyl]propionic acid and its derivatives as irreversible GR inhibitors. The K(i) and k(inact) values of 2-acetylamino-3-[4-(2-acetylamino-2-carboxyethylsulfanylcarbonylamino)phenylcarbamoylsulfanyl]propionic acid, the most potent derivative of the series, are 88 muM and 0.1 min(-1), respectively. Although the K(i) value of the inhibitor is in the micromolar range, it is more potent than N,N-bis(2-chloroethyl)-N-nitrosourea, which is currently the most commonly employed irreversible GR inhibitor with a reported IC(50) value of 646 microM. Additional attractive features of the inhibitor include its ready availability through a one-step synthesis and good solubility in both organic and aqueous solutions.

Glutathione reductase is expressed at high levels in pancreatic islet cells

Reactive oxygen species are, at least partly, involved in the diabetogenic agent-induced dysfunction of pancreatic beta-cells because the expression of antioxidative and redox proteins is low. We examined the levels of antioxidant/redox proteins, peroxiredoxins-1, -4, and -6 and glutathione reductase (GR), by immunohistochemistry and found that the expression of GR was very high in pancreatic islet cells compared to exocrine cells. When diabetes was induced by an intravenous injection of streptozotocin, the pre-administration of 1,3-bis[2-chloroethyl]-1-nitrosourea, an irreversible inhibitor of GR, made islet cells more vulnerable to streptozotocin. These data point to a pivotal role of the glutathione redox system in pancreatic islet cells against diabetogenic stress.

Detection of S-glutathionylated proteins by glutathione S-transferase overlay

Oxidative and nitrosative stress lead to the S-glutathionylation of proteins and subsequent functional impairment. Glutathione S-transferase (GST) from Schistosoma japonicum was found to bind to the glutathione moiety of S-glutathionylated proteins, thus establishing a convenient method for detecting S-glutathionylated proteins by biotinylated GST. Applications of this method to proteins that were prepared from cultured cells and blotted onto a membrane exhibited numerous positive bands, which were abolished by treatment with dithiothreitol. Treatment of a cellular extract with nitrosoglutathione led to enhanced staining of the bands in a dose-dependent manner. The method was also applicable for the histochemical detection of S-glutathionylated proteins in situ. The positive staining by biotin-GST became faint in the presence of S-glutathionylated ovalbumin, suggesting that the reaction is specific to S-glutathionylated proteins. Collectively, these data indicate that the method established here is simple and useful for detecting S-glutathionylated proteins on blotted membrane and in situ.

Metabolism of amino acids by cultured rat Sertoli cells

Sertoli cells support spermatogenesis both spatially and energetically; for this reason, these cells have important adaptations. The energetic metabolism of Sertoli cells was adapted to provide lactate and pyruvate to developing germ cells, because these substrates are essential for spermatocytes and spermatids. In this study, we investigated whether Sertoli cells use alanine, leucine, valine, and glycine as energetic substrates and whether the simultaneous addition of other nutrients, such as glucose and glutamine, might affect the metabolism of these amino acids. Alanine, leucine, valine, and glutamine are almost totally oxidized to CO2 by these cells. In contrast, glycine has been demonstrated to be a poor energetic substrate, being mainly incorporated into proteins, and their metabolism did not change in the presence of palmitic acid, glucose, and/or glutamine. The metabolism of the 3 other amino acids was modified by palmitic acid; besides, glucose changed alanine, leucine, and valine oxidation. Glutamine decreased the oxidation of alanine, leucine, and valine to CO2. Conversely, both alanine and leucine decreased the oxidation of glutamine. Our present findings show that Sertoli cells can adapt its energy metabolism to the oxidative substrates available to fulfill their role in spermatogenic energetic supply.

Molecular Cloning, Identification and Characteristics of a Novel Isoform of Carbamyl Phosphate Synthetase I in Human Testis

A gene coding a novel isoform of carbamyl phosphate synthetase I (CPS1) was cloned from a human testicular library. As shown by cDNA microarray hybridization, this gene was expressed at a higher level in human adult testes than in fetal testes. The full length of its cDNA was 3831 bp, with a 3149 bp open reading frame, encoding a 1050-amino-acid protein. The cDNA sequence was deposited in the GenBank (AY317138). Sequence analysis showed that it was homologous to the human CPS1 gene. The putative protein contained functional domains composing the intact large subunit of carbamoyl phosphate synthetase, thus indicated it has the capability of arginine biosynthesis. A multiple tissue expression profile showed high expression of this gene in human testis, suggesting the novel alternative splicing form of CPS1 may be correlated with human spermatogenesis.