The in vitro effects of melatonin on human sperm function and its scavenging activities on NO and ROS

Various systems of antioxidants exist endogenously in the body to help protect it against free radical damage by scavenging excessive ROS and RNS. Melatonin, a hormone secreted by the pineal gland, and responsible for controlling the circadian rhythm, is one such endogenous antioxidant. Melatonin has been reported to be present in human seminal fluid, but its antioxidant activities in semen are rather contradictory. This study aimed at establishing the effects of melatonin treatment on human spermatozoa. Spermatozoa were incubated with 2 mm melatonin (120 min, 37 °C, 5% CO₂) after which motility parameters were measured by computer aided motility analysis, while cell viability (PI), intracellular NO (DAF‐2/DA) and ROS (DCFH‐DA) were assessed using flow cytometry. In vitro melatonin treated samples (n = 12) showed a significantly higher percentage of motile, progressive motile and rapid cells, while simultaneously reducing the number of nonviable spermatozoa when compared with the control. Endogenous NO was significantly decreased, but no effect was observed on ROS levels. From these results, it can be concluded that melatonin was able to directly or indirectly scavenge NO, as indicated by the reduction in 4,5‐diaminofluorescein‐2/diacetate fluorescence. Future studies will indicate whether melatonin treatment during sperm preparation techniques could protect spermatozoa from excessive NO production.     

High level of intracellular sperm oxidative stress negatively influences embryo pronuclear formation after intracytoplasmic sperm injection treatment

This study evaluates the relationship between sperm intracellular reactive oxygen species (ROS; H₂O₂, O₂), DNA fragmentation (DF), low mitochondria membrane potential (MMP) of sperm and normal pronuclear formation among intracytoplasmic sperm injection (ICSI) patients. Semen samples were obtained from 62 infertile male who were candidates for ICSI treatment. After sperm processing, metaphase II (MII) oocytes were injected, and the mean percentages of intracellular ROS, MMP and DF were evaluated using flow cytometry. The mean percentages of pronuclear formation and zygote score (Z) were also recorded, and Pearson, Spearman's rank correlation coefficient and Kruskal–Wallis tests were applied to analyse the data. The amounts of sperm intracellular H₂O₂ and ˙ had significant positive correlation with low MMP (P < 0.01). The intracellular ROS had a negative correlation with pronuclear formation (P < 0.05), and its effect was higher than 66.66%. In addition, the mean percentages of neither H₂O₂ nor ˙ affected the quality of pronuclear embryos (Z‐score). This study shows that although high levels of both sperm intracellular H₂O₂ and ˙ in ICSI patients have deleterious effect on sperm MMP, only H₂O₂ may interfere in pronuclear formation.     

The efficacy of antioxidants in sperm parameters and production of reactive oxygen species levels during the freeze-thaw process: A systematic review and meta-analysis

To investigate the impact of antioxidants in sperm parameters and reduction in reactive oxygen species production during the freeze-thaw process. PubMed, Scopus, Web of Science, Embase and Cochrane central library were systematically searched. Of the 1583 articles, 23 studies were selected for data extraction. Our results show that antioxidants improved sperm progressive motility (standardised mean difference (SMD) = 1; 95% CI: 0.62, 1.38; p < .001) and viability (SMD = 1.20; 95% CI: 0.50, 1.91; p = .001) and reduced sperm DNA fragmentation (SDF) and hydrogen peroxide (H₂O₂) production, but there was no significant improvement in total sperm motility after thawing. Acetyl-l-carnitine/l-carnitine, melatonin and catalase had a significant positive impact on progressive motility. The role of tempol and melatonin in improving viability was significant compared to other antioxidants. Moreover, a significant reduction in SDF was observed after addition of butylated hydroxytoluene, tempol and vitamin E. However, the prevention of H₂O₂ production was significant only after the addition of tempol. Our overall results displayed the positive impact of antioxidants on progressive sperm motility, viability and reduction in SDF and H₂O₂ production, but no significant impact of antioxidants on total sperm motility was seen during the freeze-thaw process.     

In vitro antioxidant effect of curcumin on human sperm quality in leucocytospermia

Decreased sperm quality was caused by oxidative stress in semen from patients with leucocytospermia. Curcumin is a traditional Chinese herbal monomer extracted from Zingiberaceae turmeric and zedoary turmeric and has antioxidative and anti‐inflammatory effects. This study aimed to investigate the effects and specific molecular mechanisms of curcumin on sperm quality in patients diagnosed with leucocytospermia. Forty cases of semen samples were collected from patients with leucocytospermia and 35 cases from normal fertile male. Computer‐assisted semen analysis (CASA) was used to detect sperm motility after curcumin incubation. ELISA was used to measure the changes in H₂O₂, sperm mitochondrial DNA (mtDNA), cytochrome B (Cyt B) and NADH dehydrogenase 5 (NADH5) contents before and after curcumin treatment. The results indicate that curcumin can significantly improve sperm motility from the patients with leucocytospermia. After curcumin treatment, the level of the H₂O₂ was significantly decreased in the supernatant of curcumin‐incubated spermatozoa from leucocytospermic patients. The content of mtDNA was significantly decreased, while the content of Cyt B and NADH5 in spermatozoa was significantly increased. In conclusion, curcumin can significantly improve sperm motility of leucocytospermic patients, against the oxidative damage induced by H₂O₂. Therefore, curcumin may play a role in mitigating the H₂O₂‐induced injury to sperm.     

Antioxidant effects of penicillamine against in vitro-induced oxidative stress in human spermatozoa

Oxidative stress contributes importantly to the aetiology of male infertility, impairing sperm function. The protective effect of antioxidants on seminal parameters has been established, and the antioxidant penicillamine has shown beneficial effects; however, its protective effect on human spermatozoa exposed to oxidative stress has not been reported. The objective of this work was to evaluate the effect of penicillamine on human spermatozoa exposed in vitro to oxidative stress. First, the effect of penicillamine on spermatozoa from normozoospermic donors was evaluated. Then, the effect of penicillamine on spermatozoa exposed to oxidative stress induced separately by ionomycin and hydrogen peroxide (H₂O₂) was analysed. An untreated control and a control treated only with the oxidative stress inducer were included. Reactive oxygen species (ROS) levels, viability, mitochondrial membrane potential (MMP) and motility were analysed. The results showed that penicillamine, added to the incubation medium, decreased the ROS levels induced by ionomycin and H₂O₂, and this effect was associated with better preservation of MMP, motility, and ATP levels. These results highlight the potential advantages of penicillamine supplementation of sperm culture medium, especially for semen samples with high ROS levels and also in circumstances where laboratory handling can cause an increase in ROS production.     

Testicular tissue nitric oxide and thiobarbituric acid reactive substance levels: evaluation with respect to the pathogenesis of varicocele

The aim of the present study is to evaluate tissue nitric oxide (NO) and thiobarbituric acid reactive substance (TBARS) levels in testicular tissue, and to determine their relationship with seminal parameters in order to explain possible effects on varicocele pathophysiology.Ten adult male Wistar rats at 8 weeks old underwent partial left renal vein ligation. A sham operation was performed on control rats in a second group of another ten rats. All animals were killed 4 weeks after surgery. The testes were removed and histological changes were observed by light microscopy with haematoxylin and eosin stain on half of each testis. The rest of testis was used for the evaluation of testicular tissue NO and TBARS levels. Epididymal aspirated seminal plasma was used for semen analysis and morphological analysis was carried out according to Krugers criteria. Statistical analysis was performed by using Mann-Whitney U-tests and Spearman rank correlations between the two groups for NO and TBARS levels and for seminal parameters. Testicular tissue NO and TBARS levels (mean±SEM) were 62.8±10.1 mol/g protein and 4.7±0.3 nmol/g protein in group 1. These parameters were 16.9±2.2 mol/g protein and 3.1±0.2 nmol/g protein in the group 2 controls. There were significant differences between these parameters (P_NO=0.000, P_TBARS=0.001). Although a positive and significant correlation between testicular tissue NO and TBARS levels was found (r_s=0.739, P=0.014), there was only a strong negative correlation between NO levels and sperm motility in group 1 (r_s=–0.815, P=0.004). We found that this effect of NO on sperm motility was independent from TBARS levels after regression analysis (r²=-0.687, =0.825, P=0.034). Although there were statistically significant differences in seminal parameters between the two groups, there was no difference between them in the histopathological examination. We found that sperm motility was significantly related to testicular tissue NO levels only. Thus, we suggest that NO is an important mediator in the pathogenesis of varicocele. TBARS and other substances have been effective via NO pathways.     

Effect of tertiary‐butyl hydroperoxide (TBHP)‐induced oxidative stress on mice sperm quality and testis histopathology

Male infertility is responsible for approximately 50% of infertility worldwide. Reactive oxygen species are one of the major causes of male infertility. In this study, the effects of oxidative stress induced by tertiary‐butyl hydroperoxide (TBHP) on sperm quality and testis tissue are investigated. After determination of LD₅₀, TBHP with a concentration of 1 : 10 LD₅₀ was injected in adult male mice strains Balb/c for two consecutive weeks. Their testis tissues were used for cell viability, histopathology analysis and ROS assay. The epididymis was also surveyed for sperm analysis by CASA system. The sperm motility, count and viability decreased in the TBHP‐treated mice compared to the control mice. The flow cytometry analysis showed a significant increase in H₂O₂ and levels in both testis and sperm within 2 weeks after intraperitoneal injection. Body weights revealed no treatment‐related effects, but atrophy of testis and a decrease of testis cells viability were observed. The results showed that exposure to TBHP could lead to morphological changes in seminiferous tubules. TBHP‐induced oxidative stress caused a decrease in sperm parameters and testis cells viability. That is due to an increase level of ROS in the testis and their deleterious effects on genomic levels.     

Alpha‐lipoic acid minimises reactive oxygen species‐induced damages during sperm processing

Shearing forces during sperm preparation for assisted reproduction techniques may lead to excessive production of reactive oxygen species (ROS) which may have an unpleasant effect on embryonic development. In the current study, we assessed the effect of alpha‐lipoic acid (ALA) on ROS‐induced damages during sperm preparation process. Semen samples were collected from 15 normozoospermic men. Each semen sample was divided into two parts; one part was washed and centrifuged with sperm washing medium plus 0.02 mM ALA. Then, sperm pellet was diluted and incubated for 1 hr at 37°C in sperm washing media in the absence (ALA?) or presence of 0.02 mM ALA (ALA+). The second part was washed and centrifuged with sperm washing media in the absence of ALA, and then, sperm pellet was incubated for 1 hr at 37°C in sperm washing media in the absence (ALA?) or presence of 0.02 mM ALA (ALA+). Sperm viability, motility, intracellular oxidative stress and DNA fragmentation were assessed by eosin‐nigrosin, computer‐assisted sperm analysis system, H₂DCFDA staining and acridine orange staining respectively. Our results showed that addition of ALA as a fat‐ and water‐soluble antioxidant to sperm washing media maintains sperm viability and motility by reduction in ROS production and can also protect sperm DNA integrity.     

The effect of cysteine and glutamine on human sperm functional parameters during vitrification

Assuming the adverse effects of reactive oxygen species (ROS) on sperm function, this study was conducted to assess the effects of cysteine and glutamine as effective antioxidants on human sperm parameters under vitrification. Twenty normozoospermic samples were used. The samples were subjected to a vitrification process and cysteine (5 and 10 mM) and glutamine (10 and 15 mM). The sperm motility parameters, mitochondrial membrane potential (MMP), plasma membrane integrity (PMI), DNA damage and intracellular ROS damage were assessed for each sample. Statistical analyses showed that motility, mitochondrial membrane potential and DNA damage decreased in the vitrified groups with cysteine 5, 10 mM and glutamine 10, 15 mM separately. Also intracellular ROS increased significantly compared to the fresh group (p < .05). No significant differences were observed for PMI compared with the fresh group (p > .05). Supplementation of cysteine and glutamine in both concentrations separately decreased intracellular ROS and DNA damage of spermatozoa with significant increase in PMI, MMP and progressive motility compared to vitrified control group (p < .05). The results showed no significant effect of a specific concentration in cysteine and glutamine on sperm parameters compared to other concentrations. Both amino acids have the potential to improve the harmful effects of freezing on sperm parameters.     

Sperm quality improvement after date seed oil in Vitro supplementation in spontaneous and induced oxidative stress

In vitro supplementation with date seed oil （DSO） can protect spermatozoa against hydrogen peroxide （HiO2）- mediated damage and can improve sperm function, possibly owing to antioxidant properties. We tested the antioxidant effects of DSO on human sperm motility, sperm viability, reacted acrosome and lipid peroxidation assessed in vitro after H202-mediated oxidative damage in spermatozoa. Sixteen patients （mean age： 35 years; range： 25-45 years） referred to the Histology-Embryology Laboratory of the Medicine Faculty of Sfax for semen analysis after 12-24 months of sexual intercourse without conception were selected. After spermiogram, sperm selection by twointerface discontinuous Sill Select gradient was performed, and selected spermatozoa were used in four experimental assays： control; incubation with 100um H2O2; incubation with 0.1% DSO; and co-incubation with 0.1% DSO and 100 um H2O2. Motility and viability were determined using World Health Organization criteria. Acrosome reaction and lipid peroxidation were assessed by staining with fluorescein isothiocyanate-Pisum sativum and spectrophotometric measurement of malondialdehyde, respectively. Results showed that incubation with H2O2 alone led to a significant increase in lipid peroxidation （57.83%, P 〈 0.05） associated with a significant decrease in sperm motility, sperm viability （after 30 min and 24 h） and percentage of reacted acrosome （P 〈 0.05）. Date seed oil im- proved sperm motility after 24 h of incubation （P 〈 0.05） and protected spermatozoa against the deleterious effects of H2O2 on motility, viability, acrosome reaction and lipid peroxidation. We conclude that supplementation with DSO may have a function in antioxidant protection against male infertility.     

Reactive oxygen species mediate detrusor overactivity via sensitization of afferent pathway in the bladder of anaesthetized rats

OBJECTIVES

To investigate the effects of reactive oxygen species (ROS) on the micturition reflex in vivo, especially in bladder afferent signalling in rats, as several pathophysiological conditions in the urinary bladder (e.g. ischaemia/reperfusion and inflammation) are characterized by the formation of ROS.

MATERIALS AND METHODS

Adult female Sprague‐Dawley rats under urethane anaesthesia (normal or pretreated with 125 mg/kg capsaicin, subcutaneously, 4 days before) were assessed by continuous cystometrography (CMG) with or without the intravesical administration of H₂O₂ (0.003–3%) to stimulate ROS damage. To investigate the mechanism of H₂O₂, catalase (a H₂O₂ scavenger) was applied intravesically (2000 IU/mL), or rats were given intravenous injections with superoxide dismutase (SOD, 20 000 IU/kg, a superoxide anion scavenger), dimethylthiourea (DMTU, 100 mg/kg, a hydroxyl radical scavenger), deferoxamine (20 mg/kg, an iron‐chelator that prevents the formation of hydroxyl radical), indomethacin (3 mg/kg, a cyclooxygenase inhibitor) or ketoprofen (1 mg/kg, a cyclooxygenase inhibitor) just before or during the intravesical administration of H₂O₂. Prostaglandin (PG) levels (PGE₂ and 6‐keto‐PGF_1α) were measured in the bladder of rats treated with intravesical 0.3% H₂O₂ for 30 min with or without indomethacin.

RESULTS

Intravesical administration of H₂O₂ induced detrusor overactivity, as shown by a reduction in the mean (sem ) intercontraction interval (ICI), in a dose‐dependent manner in normal rats (0.3% H₂O_2, P < 0.01, 36.2 (4.7)% of the control ICI). H₂O₂‐induced detrusor overactivity was almost abolished by catalase and significantly suppressed by DMTU, deferoxamine, capsaicin pretreatment, indomethacin or ketoprofen but not by SOD. The level of PGs was significantly increased by H₂O₂ instillation, and indomethacin significantly inhibited the increase in PGs.

CONCLUSION

These results indicate that oxidative stress induced by H₂O₂ activates capsaicin‐sensitive C‐fibre afferent pathways, at least in part, mediated via stimulation of the cyclooxygenase pathway, thereby inducing detrusor overactivity. Thus, rats treated with intravesical H₂O₂ appear to be a suitable model for the study of detrusor overactivity.     

Antioxidant effect of hydroxytyrosol on human sperm quality during in vitro incubation

The aim of the study was to evaluate the antioxidant potential of hydroxytyrosol (HT) on human sperm quality during incubation in vitro. Semen samples collected from men attending the Laboratory of Histology‐Embryology of Sfax Faculty of Medicine (Tunisia) for infertility investigations were evaluated for initial sperm parameters. Only normal selected ejaculates (n = 15) were centrifuged and incubated further with or without HT (200ug ml^?1) at room temperature for 45 min. After incubation, sperm motility and viability, DNA oxidation and reactive oxygen species (ROS) production were assessed. The results showed that centrifugation significantly influenced sperm motility and viability. The supplementation of HT in incubating media improved (P = 0.01) significantly sperm viability and decreased sperm DNA oxidation (P < 0.001) and ROS levels (P = 0.03) following centrifugation. It can be concluded that supplementation of HT might be helpful to maintain the human spermatozoon after centrifugation.     

Magnetic activated cell sorting: an effective method for reduction of sperm DNA fragmentation in varicocele men prior to assisted reproductive techniques

Semen parameters of varicocele men have been usually suspected to exhibit higher levels of abnormalities including DNA fragmentation, reactive oxygen species (ROS) and apoptotic markers. Negative correlation between increased level of DNA fragmentation and assisted reproductive techniques (ART) outcome has been studied by several authors. In the current study, we aim to evaluate the possible value of magnetic activated cell sorting (MACs) technology in reduction of DNA fragmentation in infertile varicocele patients prior to ART. Semen samples, collected from 36 varicocele patients, were prepared by density gradient centrifugation (DGC). Every sample was subsequently divided into two aliquots. One aliquot was kept untouched as pre‐MACs control while the other aliquot was subjected to MACs technique, for depletion of apoptotic spermatozoa, and serves as post‐MACs test. Sperm count, motility and DNA fragmentations were evaluated for both control and test samples. Post‐MACs samples showed no deleterious reduction in total sperm motility (80.64 ± 6.97%) compared with control samples (80.97 ± 7.74%) while sperm DNA fragmentations were significantly reduced in post‐MACs samples (9.61 ± 5.62%) compared with pre‐MACs controls (12.43 ± 6.29%) (P < 0.05). It can be concluded that MACs technique is a simple, noninvasive, technique that can efficiently reduce DNA fragmentation in infertile varicocele patients prior to ART.     

In vitro reprotoxicity of carboxyl‐functionalised single‐ and multi‐walled carbon nanotubes on human spermatozoa

Reproductive toxicity of carboxyl‐functionalised carbon nanotubes (CNT‐COOH), as the most commonly used form of water‐soluble CNTs, is not clearly studied. The aim of this study was to investigate in vitro toxicity of carboxylated single‐walled and multi‐walled CNTs (SWCNT‐COOH and MWCNT‐COOH) against human spermatozoa. Sperm cells from healthy donors were incubated with 0.1–100 μg/ml of SWCNT‐COOH or MWCNT‐COOH at 37°C for up to 5 hr. Viability of sperm cells was assessed using MTT test, and sperm motility was evaluated following World Health Organization guideline. Production of reactive oxygen species (ROS) and nitric oxide (NO) in sperm was also assessed. We showed that both MWCNT‐COOH and SWCNT‐COOH following incubation in vitro with human spermatozoa did not exert negative effect on viability while motility was significantly (p < .05) dropped in a dose‐dependent manner. Moreover, there was no significant effect of the type, dose and exposure time of the CNT‐COOH on NO production. Exposure of sperm cells to both examined types of CNTs at concentrations as low as 0.1 μg/ml caused a significant increase in ROS levels. In conclusion, carboxylated forms of CNTs seem to be harmful for human spermatozoa. Further studies, especially using in vivo models, are needed to decide about reprotoxicity of carboxylated forms of CNTs.     

Kolaviron protects against ethylene glycol monoethyl ether‐induced toxicity in boar spermatozoa

This study investigated the ameliorative effects of kolaviron (a biflavonoid from the seed of Garcinia kola) and vitamin C on ethylene glycol monoethyl ether (EGEE)‐induced oxidative damage in boar spermatozoa in vitro. EGEE (1.0 mm ) was incubated with boar spermatozoa for 3 h with or without either kolaviron (50 and 100 μm ) or vitamin C (1.0 mm ). Spermatozoa parameters were determined hourly during the incubation period, whereas aminotransferases and alkaline phosphatase activities and oxidative stress indices were assessed after the incubation period. Results showed a time‐dependent decline in spermatozoa motility and viability with significant elevation in total abnormalities in EGEE‐treated spermatozoa. Exposure to EGEE resulted in significant increase in aminotransferases, alkaline phosphatase and superoxide dismutase (SOD) activities, whereas it markedly decreased glutathione (GSH) level, catalase (CAT) and glutathione S‐transferase (GST) activities with concomitant increase in hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) levels. Pre‐treatment of spermatozoa with kolaviron or vitamin C significantly decreased H₂O₂ and MDA levels, improved spermatozoa characteristics and ameliorated oxidative damage in EGEE‐treated spermatozoa. Taken together, EGEE exhibited its spermatotoxicity via induction of oxidative stress. The protective effects by kolaviron and vitamin C against EGEE‐induced oxidative damage may be due to their intrinsic antioxidative potentials.     

Short‐term storage of salmonids semen in a sodium alginate‐based extender

Short‐term storage of semen is a useful strategy for preservation of fish spermatozoa. However, there is a significantly decrease on sperm function mainly due to oxidative stress. In this way, sodium alginate plays an important role as free radical scavenger compound. Accordingly, the aim of our study was to analyse the effect of a sodium alginate‐based extender on sperm function in the short‐term storage of salmonids semen. Samples of Salmo salar, Oncorhynchus kisutch, and Oncorhynchus mykiss were stored in Storfish^® (Ext‐C) and Storfish^® supplemented with sodium alginate (Ext‐A) during 10 days at 4°C. After storage, motility, viability, mitochondrial membrane potential (ΔΨmit), superoxide anion (O₂^?) level and DNA fragmentation (DNA Frag) were assessed. Ext‐A had positive effect in preservation of sperm motility, viability, ΔΨmit, O₂^? level and DNA integrity in the three species analysed compared to control samples. In Ext‐A, the spermatozoa of S. salar and O. mykiss showed significantly higher motility, viability and ΔΨmit than O. kisutch. However, O. kisutch and O. mykiss had significantly lower O₂^? level than S. salar, and DNA fragmentation in O. kisutch and S. salar was significantly lower than in samples of O. mykiss (p < 0.05). Dilution of salmonids semen in a sodium alginate‐based extender is effective for protecting sperm quality during 10 days of short‐term storage.     

Seminal androgens,oestradiol and progesterone in oligoasthenoteratozoospermic men with varicocele

This study aimed to assess seminal androgens, oestradiol, progesterone levels in oligoasthenoteratozoospermic (OAT) men with varicocele (Vx). In all, 154 men with matched age and body mass index were investigated that were divided into healthy fertile controls (n = 35), OAT men with Vx (n = 55), OAT men without Vx (n = 64). They were subjected to assessment of semen parameters, seminal levels of testosterone (T), androstenedione (A), 5α‐androstane‐3 α,17 β‐diol (3 α‐diol), oestradiol (E₂), 17‐hydroxyprogesterone (17‐OHP) and progesterone (P). Seminal levels of T and A were significantly decreased where seminal levels of 3 α‐diol, E₂, 17‐OHP, P were significantly higher in OAT men with/without Vx compared with fertile controls. Sperm count, sperm motility and sperm normal forms percentage demonstrated significant positive correlation with seminal T and A and significant negative correlation with seminal 3 α‐diol, E₂, P. It is concluded that in fertile men, seminal T and A are significantly increased and seminal 3 α‐diol, E₂, 17‐OHP, P are significantly decreased compared with infertile OAT men with/without Vx. Association of Vx demonstrated a nonsignificant influence on these hormonal levels in OAT cases. Sperm count, sperm motility and sperm normal forms demonstrated significant positive correlation with seminal T, A and significant negative correlation with seminal 3 α‐diol, E₂, P.     

Berberine ameliorates experimental varicocele‐induced damages at testis and sperm levels; evidences for oxidative stress and inflammation

The present study was performed to show the ameliorative effect of berberine (BBR), as an antioxidant and anti‐inflammatory agent, against experimental varicocele (VCL)‐induced molecular and histological damages. For this purpose, 50 mature Wistar rats were divided into control, control‐sham, VCL‐sole, 50 mg/kg and 100 mg/kg BBR‐treated VCL‐induced groups. The tissue levels of interleukin‐6 (IL‐6), tumour necrosis factor‐α (TNF‐α), nitric oxide (NO), total antioxidant capacity (TAC), malondialdehyde (MDA), superoxide dismutase (SOD) and gluthatione peroxidase (GSH‐px) as well as the mRNA levels of testicular CuZn SOD, MnSOD, EC‐SOD and GSH‐px were evaluated. The serum concentration of testosterone and germ cells mRNA damage were analysed. Finally, the sperm viability, motility, DNA integrity and chromatin condensation were analysed. Observations revealed that, the BBR significantly downregulated VCL‐increased IL‐6, TNF‐α and NO levels, upregulated the CuZn SOD, MnSOD, EC‐SOD and GSH‐px mRNA level, decreased testicular MDA content, enhanced serum testosterone level and ameliorated testicular TAC, SOD and GSH‐px levels. The animals in BBR‐treated groups exhibited diminished mRNA damage versus non‐treated VCL‐induced group. The BBR has significantly (p < 0.05) improved sperm parameters. In conclusion, the BBR by promoting testicular antioxidant potential and by downregulating inflammatory reactions fairly promotes spermatogenesis and upregulates the sperm quality.     

Ascorbic acid reduces redox potential in human spermatozoa subjected to heat‐induced oxidative stress

Oxidation–reduction potential (ORP) is a new measure of oxidative stress. It is a balance between the total available oxidants and reductants. This study measures the efficiency of ascorbic acid (AA) against oxidative stress induced by either heat alone or heat and hydrogen peroxide in sperm suspensions using the MiOXSYS System. Two concentrations of ascorbic acid (400 and 600 μmol/L) were tested against heat‐ and heat plus hydrogen peroxide‐induced oxidative stress in sperm suspensions after 2 and 4 hr of incubation. Sperm motility and static oxidation reduction potential (sORP) were measured at 2 and 4 hr of incubation at three different temperatures. A significant decrease in sORP was observed as a function of AA concentration. The 600 μmol/L AA had more pronounced reduction in sORP compared to 400 μmol/L AA (p = .001). Significant decreases in sperm motility ranging from 4.89% to 14.02% were observed both as a function of incubation time and addition of H₂O₂ (p < .001). Ascorbic acid is efficacious to reduce heat‐induced oxidative stress in sperm preparations in vitro. The supplementation of ascorbic acid may be advantageous for semen preparations in IUI, IVF and ICSI.