Activity, substrate detection and immunolocalization of glutathione peroxidase (GPx) in bovine reproductive organs and semen

6-Shogaol prevents benzo (A) pyrene-exposed lung carcinogenesis via modulating PRDX1-associated oxidative stress, inflammation, and proliferation in mouse models

In this study, we have investigated the chemopreventive role of 6-shogaol (6-SGL) on benzopyrene (BaP) exposed lung carcinogenesis by modulating PRDX1-associated oxidative stress, inflammation, and proliferation in Swiss albino mouse models. Mice were exposed to BaP (50 mg/kg b.wt) orally twice a week for four consecutive weeks and maintained for 16 weeks, respectively. 6-SGL (30 mg/kg b.wt) were orally administered to mouse 1 h before BaP exposure for 16 weeks. After the experiment's termination, 6-SGL (30 mg/kg b.wt) prevented the loss in body weight, increased lung weight, and the total number of tumors in the mice. Moreover, we observed that 6-SGL treatment reverted the activity of BaP-induced lipid peroxidation and antioxidants in mice. Also, 6-SGL impeded the phosphorylation of MAPK family proteins such as Erk1, p38, and Jnk1 in BaP-exposed mice. PRDX1 is an essential antioxidant protein that scavenges toxic radicals and enhances several antioxidant proteins. Overexpression of PRDX1 substantially inhibits MAPKs, proliferation, and inflammation signaling axis. Hence, PRDX1 is thought to be a novel targeting protein for preventing BaP-induced lung cancer. In this study, we have obtained the 6-SGL treatment in a mouse model that reverted BaP-induced depletion of PRDX1 expression. Moreover, pretreatment of 6-SGL (30 mg/kg b.wt) significantly inhibited enhanced proinflammatory cytokines (TNF-α, IL-6, IL-β1, IL-10) and proliferative markers (Cyclin-D1, Cyclin-D2, and PCNA) in BaP-exposed mice. The histopathological studies also confirmed that 6-SGL effectively protected the cells with less damage. Thus, the study demonstrated that 6-SGL could be a potential phytochemical and act as a chemopreventive agent in BaP-induced lung cancer by enhancing PRDX1 expression.

Deep-frying palm olein oil-fried street falafel induces testicular toxicity in rats

Falafel is the most common Egyptian street food, and deep-frying palm oil is a commonly used for frying it. The main objective of this research was to evaluate the effect of deep-frying palm olein oil-fried street falafel on testes of Wistar rats. Twenty-one adult male Wistar rats were randomly divided into three equal groups and given treatment as follows: control group received only distilled water, fresh palm olein oil (FPO) group received FPO (1 ml/100 g BW/day) and deep-frying palm olein oil (DPO) group received DPO (1 ml/100 g BW/day) orally for 28 days. Serum level of testosterone, testicular tissue oxidative status, and sperm characteristics were determined. Testicular specimens were processed for histopathological examination. The results revealed that DPO group showed a significant (p<0.01) decrease in serum testosterone with significant (p<0.01) reduction of testicular glutathione, superoxide dismutase, and glutathione peroxidase, whereas testicular malondialdehyde was markedly (p<0.001) raised. There were significant decrease in epididymal sperm count (p<0.01), sperm progress motility (p<0.001), and increase abnormal sperm rate (p<0.001) in DPO group. Testicular histology in DPO group showed structural abnormalities which are compatible with lipid peroxidation and antioxidant deficiency. In Conclusion, deep-frying palm olein oil that used for the frying falafel induces testicular abnormalities in rats.

Sodium Selenite inhibits mitophagy, downregulation and mislocalization of blood-testis barrier proteins of bovine Sertoli cell exposed to microcystin-leucine arginine (MC-LR) via TLR4/NF-kB and mitochondrial signaling pathways blockage

This study was conducted to investigate the ameliorative effect of selenium on microcystin-LR induced toxicity in bovine Sertoli cells. Bovine Sertoli cells were pretreated with selenium (Na₂SeO₃) for 24 h after which selenium pretreated and non-pretreated Sertoli cells were cultured in medium containing 10% heat activated fetal bovine serum FBS+ 80 µg/L MC-LR to assess its ameliorative effect on MC-LR toxicity. The results show that selenium pretreatment inhibited the MC-LR induced mitophagy, downregulation and mislocalization of blood-testis barrier constituent proteins in bovine Sertoli cells via NF-kB and cytochrome c release blockage. The observed downregulation of electron transport chain (ETC) related genes (mt-ND2, COX-1, COX-2) and upregulation of inflammatory cytokines (IL-6, TNF-α, IL-1β, IFN-γ, IL-4, IL-10, 1 L-13, TGFβ1) in non-pretreated cells exposed to MC-LR were ameliorated in selenium pretreated cells. There was no significant difference (P > 0.05) in the protein levels of blood-testis barrier constituent proteins (ZO-1, occludin, connexin-43, CTNNB1, N-cadherin) and mitochondria related genes (mt-ND2, COX-1, COX-2, ACAT1, mtTFA) of selenium pretreated Sertoli cell compared to the control. Taken together, we conclude that selenium inhibits MC-LR caused Mitophagy, downregulation and mislocalization of blood-testis barrier proteins of bovine Sertoli cell via mitochondrial and TLR4/NF-kB signaling pathways blockage.

Mineral profiling of ostrich (Struthio camelus) seminal plasma and its relationship with semen traits and collection day

Successful assisted reproduction techniques, with specific focus on in vitro semen storage for artificial insemination, are dependent on certain key elements which includes the biochemical profiling of semen. The objective of this study was to complete an ostrich seminal plasma (SP) evaluation by inductively coupled plasma mass spectrometry (ICP-MS) among seven males at different daily intervals (day 1, 3, 7, 11, 15, 19, 21, 23, 25, 26, 27, 28) for a period of 28 days during spring (August to September) for mineral profiling. The effect of collection day and male on sperm concentration, semen volume and seminal plasma volume, was explored as well as the relationships amongst these specific sperm traits and SP minerals. Variation amongst SP mineral concentrations, accounted for by the fixed effects of sperm concentration, semen volume, seminal plasma volume, collection day and male, ranged from 18% to 77%. Male had the largest effect on variation in SP minerals, namely: phosphorus (P), potassium (K), calcium (Ca), sodium (Na), boron (B), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), barium (Ba), arsenic (As) and selenium (Se). Sperm concentration instigated fluctuations of P, magnesium (Mg), B, zinc (Zn), Fe, aluminium (Al), Se, manganese (Mn) and lead (Pb). Semen volume had an effect on Na, K, B, Pb and Ba while seminal plasma volume only influenced variation in Na. There were fluctuations among collection days of specific micro minerals, Ni and Mo, with initial Ni concentrations being relatively greater and Mo at lesser concentrations. Semen volume, seminal plasma volume and sperm concentration varied amongst males. Sperm concentrations during the initial collection days, 1 and 3, were less than that for days 7 to 28. Significant variation of SP minerals and sperm characteristics among ejaculates and males suggest an association of these specific elements with sperm function and are, therefore, considered to be of potential importance to success of assisted reproduction technology for the ostrich. The relationship amongst sperm concentration and collection day confirms the need to conduct an initial period of collection to stabilise a greater sperm concentration to optimise sperm numbers for artificial insemination purposes.

Sodium Selenite Protects Against Silver Nanoparticle-Induced Testicular Toxicity and Inflammation

Metal nanomaterials hold great potential and play an important role in consumer products. However, the increasing use of nanomaterials has raised concern over inadvertent exposure and potential risks for human health and the environment. Henceforth, in vivo testing of nanoparticles and protection against its toxicity is required. Using rat as an animal model, effect of sodium selenite (Se), an essential trace element, on rat testes exposed to silver nanoparticles (AgNPs) was evaluated. Male rats were treated with AgNPs (5 mg/kg/b.w) i/p or Se (0.2 mg/kg/b.w) by gavage. AgNP administration decreased Glutathione (GSH) levels and activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and increased levels of malondialdehyde (MDA) and expression of interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α). However, treatment with Se increased GSH levels and activities of SOD, CAT, and GPx compared with AgNP-treated group and decreased the level of MDA and inflammatory biomarkers significantly (p < 0.05) as compared with AgNP-treated group. Light microscopic analyses also revealed that AgNP induced histopathological changes in testes tissue. Further, protection by Se on biochemical results was confirmed by alleviation of the histopathological changes in the tissue. Results show the adverse effects of AgNPs on the male reproductive tract, particularly spermatogenesis, and suggest that Se possesses significant potential in reducing AgNP-induced testicular toxicity.

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.

Induced lipid peroxidation in ram sperm: semen profile, DNA fragmentation and antioxidant status

Action of reactive oxygen species, protamination failures and apoptosis are considered the most important etiologies of sperm DNA fragmentation. This study evaluated the effects of induced lipid peroxidation susceptibility on native semen profile and identified the mechanisms involved in sperm DNA fragmentation and testicular antioxidant defense on Santa Ines ram sperm samples. Semen was collected from 12 adult rams (Ovis aries) performed weekly over a 9-week period. Sperm analysis (motility, mass motility, abnormalities, membrane and acrosome status, mitochondrial potential, DNA fragmentation, lipid peroxidation and intracellular free radicals production); protamine deficiency; PRM1, TNP1 and TNP2 gene expression; and determination of glutathione peroxidase (GPx), glutathione reductase, catalase (CAT) and superoxide dismutase activity and immunodetection in seminal plasma were performed. Samples were distributed into four groups according to the sperm susceptibility to lipid peroxidation after induction with ascorbate and ferrous sulfate (low, medium, high and very high). The results were analyzed by GLM test and post hoc least significant difference. We observed an increase in native GPx activity and CAT immunodetection in groups with high susceptibility to induced lipid peroxidation. We also found an increase in total sperm defects, acrosome and membrane damages in the group with the highest susceptibility to induced lipid peroxidation. Additionally, the low mitochondrial membrane potential, susceptible to chromatin fragmentation and the PRM1 mRNA were increased in the group showing higher susceptibility to lipid peroxidation. Ram sperm susceptibility to lipid peroxidation may compromise sperm quality and interfere with the oxidative homeostasis by oxidative stress, which may be the main cause of chromatin damage in ram sperm.

Evaluation of Lasting Effects of Heat Stress on Sperm Profile and Oxidative Status of Ram Semen and Epididymal Sperm

Higher temperatures lead to an increase of testicular metabolism that results in spermatic damage. Oxidative stress is the main factor responsible for testicular damage caused by heat stress. The aim of this study was to evaluate lasting effects of heat stress on ejaculated sperm and immediate or long-term effects of heat stress on epididymal sperm. We observed decrease in motility and mass motility of ejaculated sperm, as well as an increase in the percentages of sperm showing major and minor defects, damaged plasma and acrosome membranes, and a decrease in the percentage of sperm with high mitochondrial membrane potential in the treated group until one spermatic cycle. An increased enzymatic activity of glutathione peroxidase and an increase of stressed cells were observed in ejaculated sperm of the treated group. A decrease in the percentage of epididymal sperm with high mitochondrial membrane potential was observed in the treated group. However, when comparing immediate and long-term effects, we observed an increase in the percentage of sperm with low mitochondrial membrane potential. In conclusion, testicular heat stress induced oxidative stress that led to rescuable alterations after one spermatic cycle in ejaculated sperm and also after 30 days in epididymal sperm.

Gestational form of Selenium in Free-Choice Mineral Mixes Affects Transcriptome Profiles of the Neonatal Calf Testis, Including those of Steroidogenic and Spermatogenic Pathways

In areas where soils are deficient in Selenium (Se), dietary supplementation of this trace mineral directly to cattle is recommended. Because Se status affects testosterone synthesis and frequency of sperm abnormalities, and the form of Se supplemented to cows affects tissue-specific gene expression, the objective of this study was to determine whether the form of Se consumed by cows during gestation would affect the expression of mRNAs that regulate steroidogenesis and/or spermatogenesis in the neonatal calf testis. Twenty-four predominantly Angus cows were assigned randomly to have individual, ad libitum, access of a mineral mix containing 35 ppm of Se in free-choice vitamin-mineral mixes as either inorganic (ISe), organic (OSe), or a 50/50 mix of ISe and OSe (MIX), starting 4 months prior to breeding and continuing throughout gestation. Thirteen male calves were born over a 3-month period (ISe, n = 5; OSe, n = 4; MIX, n = 4), castrated within 2 days of birth, and extracted testis RNA subjected to transcriptomal analysis by microarray (Affymetrix Bovine 1.0 ST arrays) and targeted gene expression analysis by real-time reverse-transcription PCR (RT-PCR) of mRNAs encoding proteins known to affect steroidogenesis and/or spermatogenesis. The form of dam Se affected (P < 0.05) the expression of 853 annotated genes, including 17 mRNAs putatively regulating steroidogenesis and/or spermatogenesis. Targeted RT-PCR analysis indicated that the expression of mRNA encoding proteins CYP2S1 (cytochrome P450, family 2, subfamily S, polypeptide 1), HSD17B7 (hydroxysteroid (17β) dehydrogenase 7), SULT1E1 (sulfotransferase family 1E, estrogen preferring, member 1), LDHA (lactate dehydrogenase A), CDK5R1 (cyclin-dependent kinase 5, regulatory subunit 1), and LEP (leptin) was affected (P < 0.05) by form of Se consumed by dams of developing bull calves, while AKR1C4 (aldo-keto reductase family 1, member C4) and CCND2 (cyclin D2) tended (P < 0.09) to be affected. Our results indicate that form of Se fed to dams during gestation affected the transcriptome of the neonatal calf testis. If these profiles are maintained throughout maturation, then the form of Se fed to dams may impact bull fertility and the development of Se form-dependent mineral mixes that target gestational development of the testis are warranted.

Sex- and age-dependent activity of glutathione peroxidase in reproductive organs in pre- and post-pubertal cattle in relation to total antioxidant capacity

Antioxidative/oxidative balance is crucial for proper functioning of cells and tissues. It is suggested that this balance can be partly controlled by sex steroid hormones and in consequence can exhibit age- and sex-related dependency. The aim of present study was to describe sex- and age-related changes in the activity of glutathione peroxidase (GSH-Px) with respect to total antioxidant activity (TAC) in reproductive organs of cattle. Biological samples were collected from slaughterhouse and comprised of ovaries, uterus, testes as well as livers as reference tissue. Animals were divided into group of bulls (aged between 13 and 24 months; n = 12), cows (aged between 14 and 27 months; n = 12) and female calves (aged between 2 weeks and 2 months; n = 12). Examined parameters were determined spectrophotometrically and the presence of GSH-Px isoform was confirmed by Western blotting technique. Activity of GSH-Px in genital tissues regardless of sex was significantly higher than in livers, while TAC showed opposite relationship. The differences in antioxidative parameters between testes and mature ovaries (e.g. GSH-Px-1.42 ± 0.47 nkat/mg prot vs. 1.08 ± 0.24 and 1.15 ± 0.23) were noticed as well as in chosen values between cows and female calves. Western blotting allowed the detection of cytosolic GSH-Px in all examined tissues with molecular weight around 21 kDa as monomer and around 84 kDa as tetramer depending on conditions of electrophoresis. The results may confirm the influence and regulatory role of sex steroid hormones on GSH-Px activity because the alterations were sex and age dependent.

Effect of age and environmental factors on semen quality, glutathione peroxidase activity and oxidative parameters in Simmental bulls

Taking into account that semen quality depends on animal age and climate conditions and that oxidative stress has been reported to be a common cause of infertility, the objective of this study was to monitor indicators of oxidative stress and antioxidant protection during four seasonal periods in service bulls of various age to get better insight into the significance of these factors upon evaluating service bull semen. The research was conducted over a year on 19 Simmental service bulls. Animals were divided into two groups according to age; Group I consisted of younger bulls aged two to four yrs (n=9), and Group II was comprised of older bulls aged five to ten yrs (n=10). Semen samples were obtained once in the middle of every seasonal period and blood samples for biochemical analysis were collected by jugular venipuncture immediately after ejaculate collection. The activity of total glutathione peroxidase (T-GSH-Px), selenium-dependent glutathione peroxidase (Se-GSH-Px) and selenium-independent glutathione peroxidase (non-Se-GSH-Px), together with the intensity of lipid peroxidation (thiobarbituric acid reactive substances; TBARS) and oxidative protein damage (protein carbonyl content (PCC)) were measured in seminal plasma. In samples of spermatozoa and blood serum, the activity of Se-GSH-Px and TBARS and PCC concentrations were determined. Older service bulls had significantly higher ejaculate volume in summer in comparison with younger bulls, whereas the number of spermatozoa and progressive motility percentage did not significantly vary with age. Younger animals had lower progressive motility percentage during summer than in spring, with more intensive oxidative processes observed in seminal plasma (TBARS) and spermatozoa (TBARS and PCC). Based on the results presented here, it can be concluded that younger bulls are more sensitive to elevated ambient temperatures during the summer, when intensified prooxidative processes in semen plasma and spermatozoa eventually led to decreased sperm progressive motility with consequential semen quality deterioration.

Effect of breed and sperm concentration on the changes in structural, functional and motility parameters of ram-lamb spermatozoa during storage at 4 degrees C

The objectives of this study were (1) to determine the changes in structural, functional and motility parameters of ram-lamb semen stored at two different concentrations at 4 degrees C for 8 days in egg-yolk based extender and (2) to determine the effect of breed of ram-lambs on the changes in structural, functional and motility parameters of ram-lamb semen from different breeds stored at two different concentrations at 4 degrees C for 8 days in egg-yolk based extender. Two different concentrations suitable for laparoscopic and cervical insemination were employed in this experiment. A total of 14 ram-lambs (Polled Dorset-5, Suffolk-5, Katahdin-4) with satisfactory breeding potential were selected. Semen samples were collected by electro-ejaculation. Semen samples were extended to 50 and 200 million sperm per ml with a commercial egg yolk based extender (Triladyl, Minitube of America, Verona, WI, USA) at room temperature and were stored at 4 degrees C. The sperm DNA fragmentation index (DFI), percentages of high mitochondrial membrane potential (hMMP) and plasma membrane integrity (PMI) were assessed using flow cytometry as part of structural and functional parameters on Days 0, 1, 4, 6, and 8. A computer assisted sperm analyser (HTM-IVOS, Version 10.8, Hamilton Thorne Research, Beverly, MA, USA) was used to assess the sperm motility parameters on Days 0, 1, 4, 6, and 8. PROC MIXED procedure was used to determine the effect of days of storage, concentration and breed. The concentration and days of storage significantly affected the sperm structural, functional and motility parameters (P<0.0001). Significant concentration x days of storage interaction was found for all structural and functional parameters. There was a significant concentration x days of storage interaction for average path velocity, curvilinear velocity, straightness and linearity. Overall changes in the sperm structural, functional and sperm motility parameters over the storage period were less dramatic in the 200 x 10(6) ml(-1) concentration when compared to 50 x 10(6) ml(-1) concentration. The hMMP and total progressive motility were influenced by breed. In conclusion, the quality of structural, functional and motility parameters declined as days of storage were increased and the magnitude of changes in the parameters was less dramatic at the higher concentration.