Insights into differentiation and function of the transition region between the seminiferous tubule and rete testis.

Seminiferous tubules physically connect to the rete testis through short segments called the transition region (TR). During fetal development, this specialized junction is considered the initial site where testis cords begin to form and to grow in length well beyond birth and into adulthood and form convoluted tubular cores. Mitotic activity of the Sertoli cell, the somatic cell of the epithelium, ceases before puberty, but modified Sertoli cells in the TR remain immature and capable of proliferation. This review presents what is known about this specialized region of the testis, with an emphasis on the morphological, molecular and physiological features, which support the hypothesis that this short region of epithelial transition serves as a specialized niche for undifferentiated Sertoli cells and spermatogonial stem cells. Also, the region is populated by an elevated number of immune cells, suggesting an important activity in monitoring and responding to any leakage of autoantigens, as sperm enter the rete testis. Several structure/function characteristics of the transition region are discussed and compared across species.

Fluted pumpkin seeds protect against busulfan-induced oxidative stress and testicular injuries in adult mice.

Fluted pumpkin is traditionally claimed to improve fertility health of male adult subjects. This study evaluated the adjuvant protective potential of fluted pumpkin seeds (FPS) extract on the deleterious effects of busulfan on the testes. Tubular germ cell depletion was induced in the testis of mice by i.p. administration of busulfan (15 mg/kg body wt. two injections, seven days apart) and the effect of ethanolic extract of FPS (200 mg/kg body wt.) was investigated after 40 days of oral administration. Busulfan caused extensive damage to the seminiferous epithelium, decreased Johnsen's score index for spermatogenesis and number of Leydig cells (p < 0.05) in the interstitial areas. Co-treatment with FPS improves the testicular cyto-architecture and re-population of the seminiferous tubules with spermatogonia, spermatocytes and spermatids (p < 0.05). Interestingly, administration of FPS increases Leydig cells count in the interstitial areas (p < 0.05) and plasma testosterone but not follicle stimulating hormone and luteinizing hormone concentrations. This study established that FPS prevented oxidative damage and increased the number of spermatogonia, spermatids, spermatocytes and Leydig cells thereby restoring spermatogenesis in busulfan-treated mice. Thus FPS is a potential complementary adjuvant during chemotherapy-induced tubular germ cell depletion.

Telfairia occidentalis-supplemented diet induces changes in sperm parameters and testosterone level in rats.

The growing patronage on herbal remedies and formulations from natural products in most developing countries has warranted research into certain health challenges including their antifertility effects. This study assessed the effects of boiled Telfairia occidentalis (TO) seed-supplemented diets on the level of testosterone and semen quality in Wistar rats. Boiled TO seed diets at 10%, 15% and 30% were given to rats for 60 days. Our study showed that sperm quality was impaired as evidenced by the decreased number of motile spermatozoa, epididymal sperm numbers, percentage live/dead ratio and increased numbers of abnormal spermatozoa comparable to control values (p < .05). Feeding of rats with 10% and 15% TO seed-supplemented diets increased testosterone levels nonsignificantly, while in the 30% TO seed diet animals, the level of serum testosterone was found to decrease significantly compared to control values. Furthermore, TO diet caused a nonsignificant increase in the activity of superoxide dismutase and the concentrations of reduced glutathione and malondialdehyde except for the significant increase in malondialdehyde level in the testes of the 10% TO diet group. A nonsignificant decrease in myeloperoxidase activity was also observed in the 10% and 15% but not 30% TO diet group. Histological damages characterised by severe loss of germ cells were more pronounced in the 10% TO diet group. Fourier transform infrared spectroscopy analysis of boiled TO seeds revealed the presence of esters, alkenes, hydroxyl and alcohol functional groups. Thus, boiled TO seed-supplemented diet evoked antifertility effects in rats, and the effects on the toxicity end points investigated were not dose-dependent.

Oral administration of Moringa oleifera oil but not coconut oil prevents mercury-induced testicular toxicity in rats.

This study was conducted to compare the effects of administration of coconut oil (CO) and Moringa oleifera oil (MO) on testicular oxidative stress, sperm quality and steroidogenesis parameters in rats treated with mercury chloride (HgCl2 ). After 15 days of oral administration of CO (2 ml kg-1 body weight) and MO (2 ml kg-1 body weight) along with intraperitoneal (i.p.) administration of HgCl2 (5 mg kg-1 body weight) alone or in combination, we found that CO treatment did not protect against HgCl2 -induced poor sperm quality (motility, count) as well as decreased testosterone level and 17ß-hydroxysteroid dehydrogenase (17ß-HSD) activity. Treatment with CO alone decreased glutathione (GSH), and glutathione peroxidase (GSH-Px) activities and increased malondialdehyde (MDA) level in rat's testis, whereas MO did not change these parameters. Cotreatment with MO prevented HgCl2 -induced testicular catalase (CAT) and superoxide dismutase (SOD) activities, poor sperm quality and low testosterone level and also blocks the adverse effect of CO+HgCl2 (2 ml kg-1 body weight + 5 mg kg-1 body weight) on the investigated endpoints. In conclusion, MO and not CO decreased the deleterious effects of HgCl2 on sperm quality and steroidogenesis in rats and also strengthen the antioxidant defence of the testes. Therefore, MO is beneficial as an antioxidant in HgCl2 -induced oxidative damage.

Rutin, an antioxidant flavonoid, induces glutathione and glutathione peroxidase activities to protect against ethanol effects in cadmium-induced oxidative stress in the testis of adult rats.

Exposure to cadmium (Cd) reduces sperm quality and induces oxidative stress in the testis. Rutin is an effective antioxidant flavonoid. We studied the effect of ethanol (EtOH, 5 g/kg b.wt.) intake on Cd (50 mg/kg b.wt.)-induced testicular toxicity with or without RUT pre-treatment (25, 50, 100 mg/kg b.wt.) in rats. At the end of the 15-day oral treatment, co-treatment with EtOH decreased the activities of glutathione (GSH), GSH-peroxidase and superoxide dismutase resulting to slight increase in the testicular MDA level compared to Cd-treated rats. The Cd+EtOH animals had higher levels of abnormal spermatozoa, decreased epididymal sperm number and serum testosterone levels (p < .05) compared to the Cd-treated animals. Rutin co-administration protected against the EtOH effects in a dose-dependent manner, with the Cd+EtOH+50 mg/kg RUT- and Cd+EtOH+100 mg/kg RUT-treated animals having higher GSH and GSH-Px activities beyond the control values (p < .05). In a supplementary study, animals treated daily with RUT alone (25, 50, 100 mg/kg b.wt.) for 15 days dose-dependently increased testicular GSH-peroxidase and GSH activities by 9.38%, 31.25%, 56.25% and 7.14%, 32.14%, 60.71%, respectively, compared to control values. Therefore, RUT induces GSH and GSH-Px activities to protect against Cd+EtOH-induced testis oxidative stress in rats.

Antioxidant enzymes activity, lipid peroxidation, oxidative damage in the testis and epididymis, and steroidogenesis in rats after co-exposure to atrazine and ethanol.

Concomitant alcohol use and exposure to xenobiotics can adversely affect gonadal functions. This study investigated the oxidative status of the testis and epididymis and steroidogenesis of rats co-exposed to ethanol (EtoH, 5 mg kg(-1) b.wt.) and atrazine (ATZ, 50, 100, 300 mg kg(-1) b.wt.) for 3 weeks. The activities of catalase, superoxide dismutase, glutathione peroxidase, as well as the concentrations of glutathione and malondialdehyde, as indicators of oxidative stress were measured in the homogenates of the testis and epididymis. Testosterone and cholesterol concentrations as well as 17ß-hydroxysteroid dehydrogenase (17ß-HSD) activity were assayed in the plasma and testis respectively. After the administration of EtoH alone, or in combination with different doses of ATZ, oxidative damage as evident by malondialdehyde level was not observed in both the testis and epididymis. The combine exposure group showed dose-dependent decrease in plasma testosterone and testis cholesterol level and increase in testis 17ß-HSD activity compared to the EtoH group. Furthermore, the testes and epididymis of the EtoH-exposed rats treated with high dose of ATZ had severe histopathological damage. Therefore, ATZ-exposed alcohol-treated rats have histological damage of the testis and epididymis and lower testosterone level than EtoH-treated rats.

Quercetin exacerbates the effects of subacute treatment of atrazine on reproductive tissue antioxidant defence system, lipid peroxidation and sperm quality in rats.

The study investigated the reproductive function and the antioxidant defence system of rats co-exposed to atrazine [ATZ, 120 mg kg(-1) body weight (b. wt)] and quercetin (QT, 20 mg kg(-1) b. wt.). ATZ had no significant effects on feed intake, body weights and reproductive organs weight except prostate weight. Sperm abnormalities were increased, whereas sperm production, sperm motility and epididymal and testicular sperm numbers were decreased with ATZ treatment. Antioxidant enzymes including superoxide dismutase, glutathione-S-transferase and glutathione peroxidase were significantly altered in the epididymis and testis resulting to lipid peroxidation. A potentiating response on glutathione-S-transferase and aspartate aminotransferase activities in the testis and on lactate dehydrogenase activity and glutathione level in the epididymis was observed in the QT + ATZ animals. Quercetin alone decreased seminal vesicle and prostate weights, increased superoxide dismutase activity in the testis and ascorbate level in the epididymis. Mild pathological changes were observed in the ATZ group, whereas considerable necrosis of seminiferous tubular cells with hypoplasia of the epithelia was observed in the QT + ATZ animals. The epididymis of these animals had multilayered and sometimes a single lining epididymal epithelium with few spermatozoa. We conclude that quercetin at the investigated dose increases the susceptibility of rat reproductive tissues to atrazine-induced oxidative damage.

The protective effects of quercetin on the cytotoxicity of atrazine on rat Sertoli-germ cell co-culture.

To evaluate the direct effect of atrazine (ATZ) and the protective effect of quercetin (QT) on testicular cells, we used primary cultures of rat Sertoli-germ cells (SGCs). ATZ (232 µm) up-regulated the mRNA expression of GATA-4, androgen receptor (AR), androgen-binding protein (ABP), steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme (CYP11A1), cyclooxygenase-2 (COX-2) and NF-κappaB (NF-κB) and down-regulated the expression of stem cell factor (SCF) mRNA. There was no change on the mRNA expression of oestrogen receptor-alpha (ER-α). Simultaneous supplementation of QT in the culture normalizes the expression of these genes. The stimulatory action of follicle stimulating hormone (10 ng/mL) on ATZ-induced StAR and CYP11A1 mRNA levels were also prevented by QT. Furthermore, ATZ-stimulatory action on AR mRNA was opposed in a dose-dependent manner in the presence of increasing concentrations of QT (10-50 µm).The dislodgement of germ cells from the Sertoli cells monolayer and decrease in SGCs viability was prevented by QT. To show whether or not the disrupted interactions of Sertoli and germ cells impaired spermatogenesis, adult male rats exposed in vivo to ATZ (50 mg/kg b.wt) for 1 week had their daily spermatozoa production (DSP) per gram testis lowered by 30%. DSP was significantly increased in the QT(10 mg/kg) + ATZ-treated rats as compared with the ATZ-treated rats. Taken together, ATZ can alter SGCs expression of spermatogenesis- and steroiodogenesis-related genes resulting in a decrease in sperm production in the testis as well as cell viability. QT might block these molecular events-induced by ATZ thereby protecting testicular Sertoli-germ cells from ATZ-induced toxicity.

Influence of quercetin on haematological indices and biomarkers of oxidative stress in the serum of rats exposed to atrazine.

The study was carried out to compare the effects of quercetin (QT) at doses of 5mg/kg (Q5) and 10mg/kg (Q10) against the hematological toxicity and oxidative stress caused by atrazine (ATR). Male rats were orally gavaged with ATR at a dose of 120mg/kg for 16 days. Erythropenia, leucopenia was observed in ATR treated rats. Other hematological variables such as packed cell volume (PCV), hemoglobin concentration (HGB), mean cell hemoglobin concentration (MCHC), mean corpuscular volume (MCV), neutrophils (NEU), lymphocytes (LYM) and blood platelet (PLT) showed no significant change with respect to the control values. The activities of the antioxidant defense molecules including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glutathione (GSH) were decreased; malondialdehyde (MDA) level increased but catalase (CAT) activity showed no change.Co-administration of Q5 did not prevent the oxidative stress and the hematological alterations caused by ATR. In these groups of animals, the values of PLT and NEUT were increased while LYM decreased indicating more pronounce hematological changes. The changes in both the biochemical and hematological variables were normalized to the control values on co-administration of Q10. We suggest that the antioxidant activities of QT at a doses of 10mg/kg could be responsible for its protective effects against ATR-induced oxidative stress and hematological toxicity.

Rutin- and selenium-attenuated cadmium-induced testicular pathophysiology in rats.

Cadmium (Cd) is known to cause oxidative damage in the testes of rats. The aim of this study was to investigate the protective role of rutin (RUT, 30 mg/kg) and selenium (Se, 0.15 ppm) alone or in combination against Cd (200 ppm)-induced lipid peroxidation, steroidogenesis and changes in antioxidant defence system in the rat testes. The obtained results showed that Cd increased lipid peroxidation and abnormal sperm count and decreased plasma testosterone, lactate dehydrogenase, acid phosphatase, alkaline phosphatase and testicular steroidogenic enzymes: 3ß-hydroxysteroid dehydrogenase (HSD), 17ß-HSD activities as well as epididymal sperm counts and motility, while RUT and Se treatment reversed this change to control values. Acute intoxication with Cd was also followed by significantly decreased activity of the antioxidant defence system (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione (GSH), and glutathione-S-transferase (GST)). Treatment with RUT and Se reversed Cd-induced alterations of antioxidant defence system and significantly prevented Cd-induced testes damage and depletion of plasma and testicular Se levels. RUT and Se appear not to have more profound effects than their separate effects against Cd-induced testicular toxicity, although Se was more potent than RUT in the recovery of testosterone levels. These results suggest that both RUT and Se do not have synergistic role against Cd-induced testicular injury.

Rutin Ameliorates Cyclophosphamide-induced Reproductive Toxicity in Male Rats.

Cyclophosphamide (CYC) as an anticancer alkylating agent has been known as a male reproductive toxicant. This study was aimed to evaluate the protective effect of rutin (RUT) on CYC-induced reproductive toxicity. Sexually mature Wistar rats (weighing 199 ± 10 g with five animals in each group) were given CYC (15 mg/kg) and/or RUT (30 mg/kg) twice a week via gavage for 4 weeks. The sperm counts, sperm motility, sperm morphology, daily sperm production (DSP), testicular, and epididymal antioxidant systems: superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione reductase (GR), glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and testicular steroidogenic enzymes (3ß-hydroxysteroid dehydrogenase and 17ß-HSD and spermatogenesis marker enzymes (lactate dehydrogenase (LDH), sorbitol dehydrogenase (SDH), alkaline phosphatase (ALP), acid phosphatase (ACP) in the testes, epididymis and seminal vesicles were investigated at the end of the fourth week. By the end of the fourth week, RUT prevented lower sperm counts, sperm motility, DSP, and higher abnormal sperm numbers induced by CYC. In testes, RUT decreased SOD, LDH, and SDH and increased CAT, 3ß-HSD, 17ß-HSD, ALP, and ACP induced by CYC. In epididymis, RUT increased SOD, CAT, GSH, GSH-Px, GR, GST SDH, ALP and ACP and decreased MDA and LDH induced by CYC. In seminal vesicles, marker enzymes were unchanged in rats given CYC alone or in combination with RUT. It appears that RUT ameliorates CYC reproductive toxicity at the investigated dose.

Biflavanone-kolaviron protects human dopaminergic SH-SY5Y cells against atrazine induced toxic insult.

Atrazine (ATR) is a widespread agrochemical contaminant frequently detected in water systems and kolaviron (KV) is a seed-derived biflavonoid which is reported to modulate the effects of many mutagens and carcinogens. We investigated the protective effects of KV on ATR-induced cell death in the human neuroblastoma cell line (SHY-SY5Y). KV prevents ATR-induced generation of reactive oxygen species (ROS), cell death and inhibited cell proliferation by reduction of cell proliferation. Further, ATR-induced levels malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) activities, increased leakage of lactate dehydrogenase (LDH), inhibited cellular LDH activity and depleted glutathione (GSH) levels in SHY-SY5Y cells were blocked by KV. Comparable to the control, KV increased GR but not GSH-Px activities. ATR mediated nuclear changes associated with apoptosis; including nuclear fragmentation, condensation, DNA laddering, and increased caspase-3 activity were blocked on addition of KV. ATR-induced changes in the expressions of p53, Bax, Bcl-2, p21, and mRNA levels of caspase-3 and caspase-9 were prevented by KV. Based on these results, we propose a model for the protective effect of KV on ATR-induced cell injury in neuronal cell.

Atrazine induces transcriptional changes in marker genes associated with steroidogenesis in primary cultures of rat Leydig cells.

Reproductive toxicity of atrazine (ATZ) is well reported in mammals. However, the underlying mechanisms are poorly understood and need to be explored. Thus, we investigate ATZ induced transcriptional changes in selected markers of steroidogenesis in primary cultures of rat interstitial Leydig cells (ILCs). Cytotoxic studies were carried out by exposing the cells to ATZ (0.5-50 µg/mL or 2.32-232 µM) for 24-72 h, whereas; the exposure period of expression studies was for 2 h. ATZ exposure of (25 and 50 µg/ml) for 48 h onwards was found to be cytotoxic in MTT (dimethylthiazol-diphenyl tetrazolium bromide salt) assay, while in NRU (neutral red uptake) assay, cytotoxicity could be recorded at 50 µg/ml exposure of 72 h only. A significant dose dependent induction in the levels of mRNA expression of genes of steroidogenic acute regulatory protein (STAR), cytochrome P45011A1, 3ß-hydroxysteroid dehydrogenase (3ß-HSD), and other steroidogenic proteins were observed in cells exposed to ATZ. Our data suggest the applicability of these selected marker genes of steroidogenesis as an indicator of short term exposure of ATZ induced testicular toxicity in rats interstitial Leydig cells (ILCs).