Sperm DNA Denaturation Research Articles

Effect of St. John's Wort (Hypericum perforatum L.) on Male Sexual and Reproductive Health: A Narrative Review.

Hypericum species are widely acknowledged for their biological attributes, with notable attention being paid to Hypericum perforatum, commonly known as St. John's wort (SJW) within the Hypericum section of the Hypericaceae family. This species is among the most thoroughly investigated herbal medicines, particularly in terms of its application in the management of mild to moderate depression. SJW is used to treat depression, menopausal symptoms, attention-deficit hyperactivity disorder (ADHD), somatic symptom disorder, obsessive-compulsive disorder, and skin conditions, such as wounds and muscle pain. However, the usefulness and effectiveness of SJW for male sexual and reproductive health (SRH) are not well known. To assess the current evidence in the literature on the effect of SJW on male SRH. This narrative review followed a predetermined protocol and used MEDLINE and PubMed to identify articles published in English on the effects of SJW on male SRH. The search used various keywords, such as "Hypericum Perforatum", "St. John's Wort", and terms related to sexual and reproductive health issues. Articles published between the inception of the database and August 2023 were included. We identified 12 articles published from 1999 to 2019, the majority of which were experimental and conducted on animals. These studies demonstrate variability in terms of design, sample size, type of SJW extract used, the dosage administered, and duration of treatment. Studies have indicated potential sexual dysfunction (SD) due to SJW, which includes reduced libido, delayed ejaculation, delayed orgasm, and erectile dysfunction. Additionally, reproductive toxicity has been suggested, as evidenced by spermicidal effects through the inhibition of sperm motility, abnormal spermatozoa, chromosomal aberrations, and DNA denaturation. Furthermore, some studies have reported potential adverse events during maternal exposure, inhibition of fertilization, and disruption of reproductive parameters. Our review suggests that the safety and efficacy of SJW in the treatment of human SRH remain unclear. Further comprehensive, well-designed studies with larger samples, longer exposure periods, and specific dosages are needed to clarify SJW's effects of SJW. Therefore, consultation with healthcare professionals before using herbal remedies or supplements is crucial.

Efficacy of density gradient centrifugation technique (DGC) in enhancing sperm cell DNA quality for assisted reproductive technique

ObjectiveDensity gradient centrifugation (DGC) is commonly used for sperm preparation before assisted reproductive technology (ART) procedures. This technique separates superior motile spermatozoa with normal morphology from the total sperm population. However, there is still controversy as to the effects of this sperm separation technique on sperm cell DNA integrity which is a determining element in the process of fertilization and embryonic development.The objective of this study was to determine the effects of DGC on sperm cell DNA integrity as assessed by a novel association between two cytogenetic tests.Study designsSemen samples were collected from 30 fertile donors and 40 patients being candidates for ART treatment. Each sample was divided into two parts: the first portion was subjected to selection by two layers of DGC (45% and 90%) and the second fraction was rinsed with phosphate-buffered saline solution and centrifuged without density gradient.Abnormal sperm chromatin structure as evaluated by a sperm chromatin dispersion (SCD) test and DNA denaturation as assessed by an acridine orange (AO) test were monitored in the initially washed sample and in the different layers of the density gradient centrifugation.ResultsDGC significantly improved the proportion of sperm progressive motility, total motility, and sperm morphology. Moreover, following density gradient centrifugation, the proportion of spermatozoa with denaturated DNA significantly decreased when compared with whole semen (p < 0.001). In addition, we found that spermatozoa isolated in the 90% layer possessed a significantly lower percentage of sperm chromatin decondensation when compared with those remaining in the 45% layer and unprocessed semen (p < 0.001).ConclusionsUsing double cytogenetic tests, our study shows that semen processing by density gradient centrifugation is useful in selecting sperm with higher double-strand DNA integrity and recommended to be used in sperm preparation for assisted reproduction.

Plasma-Rich in Growth Factors Ameliorates Detrimental Effects of Cryopreservation on Human Sperm: A Prospective Study.

ObjectivesSperm cryopreservation results in damage to membrane integrity, sperm viability, sperm motility, and DNA structure. We aimed to evaluate the effect of plasma rich in growth factors (PRGF) on sperm parameters during the freeze-thaw process.Materials and Methods In the first phase of this prospective study, after sperm preparation, 10 normozoospermic specimens were cryopreserved by rapid freezing with different concentrations of PRGF including 0, 1, 5, and 10% to find the optimum dose. Sperm motility and viability were assessed in this phase. In the second phase of the study, based on the results of first phase, 25 normal sperm samples were frozen with 1% PRGF. All sperm parameters including motility, viability, acrosome reaction, and DNA integrity were assessed before freezing and after thawing. Results The rates of progressive and total sperm motility and viability were significantly higher in 1% PRGF compared to control, 5%, and 10% PRGF in the first phase (P<0.05). Supplementation of freezing medium with 1% PRGF could significantly improve all sperm parameters including sperm motility, viability, normal morphology, acrosome integrity, chromatin structure, chromatin integrity, DNA denaturation, and DNA fragmentation in comparison with the control group. ConclusionIt appears that the supplementation of freezing medium with 1% PRGF could protect human sperm parameters during cryopreservation.

Trehalose Attenuates Detrimental Effects of Freeze-Drying on Human Sperm Parameters.

Freeze-drying is one of the sperm preservation methods leading to the long-term preservation of sperm genetic material. Our main goal of this study was to evaluate the effect of the trehalose freeze-drying method on sperm motility, viability, morphology, acrosome, and DNA integrity compared with a standard protocol without trehalose. Twenty-five normozoospermic samples were included in this prospective study. Direct swim-up was used for sperm preparation. An experiment was performed on freeze-dried samples containing trehalose (0.2 M), and the results were compared to that without trehalose. The sperm parameters, including count, motility, morphology, viability, acrosome reaction, DNA denaturation, and DNA fragmentation, were evaluated before and after freeze-drying in both groups. The spermatozoa were totally immotile after freeze-drying in both groups. Sperm viability, acrosome integrity, and nondenatured sperm DNA were significantly higher in the trehalose group in comparison with that of without trehalose group. Nonfragmented sperm DNA showed an increasing trend in the trehalose group compared to the group without trehalose. While freeze-drying significantly reduced normal morphology, the addition of trehalose did not affect this parameter. The results of this study showed that trehalose can attenuate the detrimental effects of freeze-drying on human sperm parameters.

Canthaxanthin protects human sperm parameters during cryopreservation.

Different antioxidants have been introduced to reduce oxidative stress during the cryopreservation. The main goal of this study was to evaluate the effects of canthaxanthin on human sperm parameters during the freeze-thaw process. This study was performed on 25 normozoospermic semen samples dividing into five groups including 0, 0.1, 1, 10, and 25µM of canthaxanthin. The prepared spermatozoa were cryopreserved by rapid freezing technique. Sperm motility, viability (eosin-nigrosin), morphology (Papanicolaou), acrosome reaction (double staining), DNA denaturation (acridine orange), chromatin packaging (aniline blue and toluidine blue), and DNA fragmentation (sperm chromatin dispersion test) were evaluated before freezing and after thawing. All sperm parameters after thawing significantly were decreased compared to before freezing. Twenty-five micromolar canthaxanthin could significantly improve the progressive and total motility, viability, normal morphology, chromatin packaging, acrosome integrity and DNA denaturation and fragmentation. Ten micromolar canthaxanthin significantly improved total motility, viability, normal morphology, chromatin packaging, acrosome integrity and DNA denaturation and fragmentation. Whereas, in 1µM group, there were significant differences only in improvement of acrosome integrity, chromatin packaging (toluidine blue) and DNA denaturation and fragmentation. But, in 0.1µM group, there were no significant differences in any of measured parameters. It seems that canthaxanthin ameliorates detrimental effects of cryopreservation on human sperm parameters.

1,3-Dinitrobenze-Induced Genotoxicity Through Altering Nuclear Integrity of Diploid and Polyploidy Germ Cells.

1,3-Dinitrobenzene (mDNB) is a widely used intermediate in commercial products and causes testicular injury. However, genotoxic effects upon low-level exposure are poorly understood. The present study evaluated the effects of very low-chronic doses of mDNB on sperm nuclear integrity. Male hamsters were treated with 1.5 mg/kg/d/4 wks (group A), 1.5 mg/kg/mDNB/d/week/4 weeks (group B), 1.0 mg/kg/mDNB/3 d/wk/4 wks (group C), or polyethylene glycol 600 (control). Nuclear integrity of distal cauda epididymal sperm was determined using the sperm chromatin structure assay and acridine orange staining (AOS). The germ cell nuclear integrity was assessed by the comet assay. Testicular histopathology was conducted to evaluate the sensitive stages. The comet assay revealed denatured nuclear DNA in group A (in diploid and polyploid cells from weeks 2-5); respectively at week 4 and weeks 3 to 4 in groups B and C. According to AOS, only group A animals exhibited denatured sperm DNA (weeks 1 and 3). The effective sperm count declined from weeks 1 to 6. Mean sperm DNA denaturation extent, percentage cells outside the main population, and standard deviation indicated altered sperm nuclear integrity in group A. Same animals exhibited progressive disruption of the Sertoli cells, while groups B and C exhibited damages on germ cells. The results suggest that mDNB affects sperm nuclear integrity at very low chronic doses targeting cell-specific testicular damage.

Sperm chromatin quality and DNA integrity in partial versus total globozoospermia

Globozoospermia is a severe form of teratozoospermia with low incidence in infertile patients, considered as one of the important causes of male infertility. The objective was to investigate the chromatin/DNA integrity as well as apoptosis in ejaculated spermatozoa of cases with partial or total globozoospermia. Fifty-seven semen samples were divided into three groups of partial globozoospermia (n=17), total globozoospermia (n=10) and normozoospermia (control; n=30). Sperm chromatin condensation, DNA integrity and apoptosis were assessed using cytochemical assays. The results showed significant differences in sperm parameters of count and motility between two case groups versus controls. The percentages of spermatozoa with abnormal chromatin packaging and protamine deficiency were significantly higher in total and partial globozoospermic men compared to normozoospermic samples. Also, the rates of TUNEL-positive spermatozoa were significantly increased in both globozoospermic cases with respect to the control (18.3±10.1 and 12.3±9.2 versus 5.9±3 respectively). However, no significant differences were noticed between two subgroups of patients with regard to sperm DNA denaturation, DNA fragmentation and apoptosis. Abnormal chromatin packaging, DNA damage and apoptosis were significantly higher in cases than controls. The sperm chromatin/DNA anomalies may be considered as one of the main aetiology of ART failure in globozoospermic patients.

Assessment of human sperm DNA integrity using two cytochemical tests: Acridine orange test and toluidine blue assay.

Primary infertility affects approximately 15% of couples, with male factor infertility accounting for 50% of cases. Semen samples from 41 patients with asthenoteratospermia and 28 men with proven fertility were analysed according to World Health Organization guidelines. Abnormal sperm chromatin structure was assessed by toluidine blue assay (TBA), and DNA denaturation (DD) was detected by the acridine orange test (AOT). The mean (±SEM) rates of DD and abnormal chromatin structure were significantly higher in infertile subjects compared to fertile group respectively p=.003 and p<.001. A significant correlation was established between sperm DD and abnormal chromatin structure (R=.431, p<.001). Sperm DNA damage correlated significantly with abnormal morphology, sperm motility and necrozoospermia. Our study shows that men with increased levels of abnormal sperm chromatin structure have a high incidence of DNA denaturation and altered semen parameters. These findings suggest that male infertility has been linked to sperm DNA damage.

The Effect of Radiation on Semen Quality and Fertility in Men Treated With Brachytherapy for Early Stage Prostate Cancer

We determined the effects of prostatic brachytherapy on semen parameters and sperm DNA integrity, and the potential impact on fertility. Five screened patients treated with brachytherapy participated in a pilot study visit to undergo early morning blood collection for serum hormone evaluation and semen collection for semen analysis and DNA integrity assay by sperm chromatin structure assay. Data on 7,617 infertile men, each with at least 1 semen analysis and sperm DNA integrity assay, were obtained from an institutional database for comparison. Published data on fertile men were compared to data on those with brachytherapy for DNA fragmentation analysis. All brachytherapy cases had normal serum luteinizing hormone, follicle-stimulating hormone and testosterone. Specific semen parameters, such as semen volume (p <0.0005), total sperm concentration (p <0.0004) and percent sperm motility (p <0.004), were significantly lower than normal reference values. As measured by the DNA fragmentation index, the mean sperm DNA fragmentation of 46.4% in brachytherapy cases was significantly higher than in the fertile group (13.3%, p <0.0003), the total infertile group (20.4%, p <0.0002) and the age matched infertile group 45 to 53 years old (27.9%, p <0.03). All men with brachytherapy had an abnormal sperm DNA fragmentation index, indicating likely infertility in all. Infertility may well be a long-term adverse effect of brachytherapy for localized, low grade prostate cancer. All men who undergo brachytherapy should be counseled about its potential impact on fertility.

The association between semen quality in workers and the concentration of di(2-ethylhexyl) phthalate in polyvinyl chloride pellet plant air

To investigate potential associations between semen quality in workers and the concentrations of di(2-ethylhexyl) phthalate (DEHP) in personal air collected from polyvinyl chloride (PVC) plants. Cross-sectional study. PVC plants in Taiwan. Forty-five male workers employed in two PVC pellet plants. None. Sperm concentration, motility, morphology, and chromatin DNA integrity were accessed. The workers were divided into low- and high-DEHP-exposed groups in accordance with the median levels of DEHP (23.7 μg/m(3)) in personal air. In the high-DEHP-exposed group, significant increases were found in the tendency for sperm DNA denaturation (αT) induction, the DNA fragmentation index (DFI), and propensity for coffee drinking. After adjusting for coffee drinking, cigarette smoking, and age, personal air concentrations of DEHP showed positive associations with αT (β = 0.038) and DFI (β = 0.140) and negative associations with sperm motility (β = -0.227). This is the first study to demonstrate a link between DEHP concentration in ambient air and the adverse effects in sperm motility and chromatin DNA integrity. Given the current wide use of these PVC products, the implications for phthalates toxicity and occupational health could be considerable.

Developmental exposure to decabrominated diphenyl ether (BDE‐209): Effects on sperm oxidative stress and chromatin dna damage in mouse offspring

Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants and have been found in human milk in recent years. This study investigates whether prenatal exposure to decabrominated diphenyl ether (BDE-209) induces sperm dysfunction in male offspring. Pregnant CD-1 mice were gavaged once daily with corn oil (control), 10, 500, and 1500 mg kg(-1) body weight of BDE-209 from day 0 of gestation to day 17. The outcomes of male reproductive parameters were assessed on postnatal day 71. Anogenital distance, sperm-head abnormalities, and testicular histopathology were significantly affected in male offspring prenatally exposed to 1500 mg kg(-1). Significant increases in the tendency for sperm DNA denaturation (αT) induction and the DNA fragmentation index (DFI) were found in those exposed to 10, 500, and 1500 mg kg(-1) (P < 0.05). We observed a significant increase of sperm hydrogen peroxide (H(2)O(2)) generation in the 10 and 1500 mg/kg/day groups compared to the control group (P < 0.05). Although our findings suggested that the mechanisms underlying BDE-209-induced sperm DNA damage and H(2)O(2) generation might not be represented as a dose-response relationship, we found that the greater the excess production of sperm H(2)O(2), the greater the sperm αT (r = 0.65, P = 0.0155) and DFI (r = 0.53, P = 0.002). In conclusion, developmental exposure to BDE-209 induced sperm-head abnormality, oxidative stress, chromatin DNA damage, and testicular histopathological changes. These findings suggest that BDE-209-induced male reproductive effects might involve the formation of sperm H(2)O(2) which attacks nucleic acids via H(2)O(2) generation.

Comparación entre el test de fragmentación de ADN espermático mediante la técnica de SCD y el índice de vitalidad medida con el test de naranja de acridina

Introduction Sperm DNA integrity is one of the most important factors currently analyzed in the study of male fertility. There are numerous publications on the utility of diverse methods analyzing sperm chromatin status. One of the simplest is the ethidium bromide/acridine orange (AO) test, which assesses the degree of sperm DNA denaturation according to its binding to acridine orange staining. However, the AO test is limited to these metachromatic properties and consequently provides limited information on the nuclear status of the sperm. Other techniques, such as the sperm chromatin dispersion (SCD) test, analyze sperm DNA fragmentation by assessing DNA strand breaks. Objective To analyze whether there is a correlation between sperm vitality measured through the ethidium bromide/AO test and DNA fragmentation measured through the SCD test. In both cases, the samples were analyzed visually. Material and methods Eighty-two semen samples from men undergoing fertility testing in the Clínica Tambre were included in this study. The ethidium bromide/AO test was used to test sperm vitality and the SCD test (Halosperm, Halotech) was used to evaluate sperm DNA fragmentation. The AO technique detects the proportion of dead sperm, depending on the degree nuclear DNA denaturation. Sperm with orange fluorescence indicate denatured DNA, while those with green fluorescence contain intact DNA. The percentage of fragmentation was measured by the improved SCD test (Halosperm). This test indicates DNA strand breaks based on the size of the halo obtained. In fragmented sperm, no halo is observed when the sample is examined with a fluorescence microscope and GelRed fluorochrome. Sperm with intact DNA show a halo. Student's t-test was used to compare the means between the two groups. Differences of p<0.05 were considered statistically significant. Results The proportion of sperm with denatured DNA detected with the AO test was significantly correlated with the proportion of sperm DNA fragmentation detected with the SCD test (r = 0.5, P < 0.001). In the 82 samples analyzed, the mean vitality index with the AO test was 20.93% (6 ± 50) versus 28.35% (7.3 ± 40) for the fragmentation index. The proportion of sperm with denatured or fragmented DNA was also positively correlated with motility. The two assays showed a statistically significant negative correlation with sperm concentration. Discussion This study demonstrates a correlation between the results of sperm vitality measured by the AO test and the degree of DNA fragmentation measured by the SCD test. These results suggest that the AO test could be the first option to determine sperm chromatin damage before more expensive or complicated tests are performed.

Changes in sperm apoptotic markers as related to seminal leukocytes and elastase

To elucidate the effects of inflammation on sperm quality, this study analysed classical sperm characteristics, leukocytes and elastase in neat semen, and sperm apoptotic markers, i.e. changes in plasma membrane phospholipid asymmetry, mitochondrial membrane potential (MMP), DNA integrity and intracellular reactive oxygen species (ROS), in semen prepared by density gradient using flow cytometry from 348 men of infertile couples. Increased leukocytes (> or = 0.1 x 10(6)/ml) were associated with a decreased sperm concentration, motility and normal morphology (P < or = 0.001). Sperm necrosis and DNA denaturation were increased (31.3 versus 26.6%, P=0.020; 15.5 versus 11.5%, P = 0.011, respectively), whereas spermatozoa with normal MMP were decreased (64.1 versus 70.0%, P=0.004). High leukocyte levels ((> or = 1 x 10(6)/ml) were not associated with any of the observed sperm parameters. At low elastase concentration (100-290 microg/l), DNA denaturation was higher (16.1 versus 10.5%, P = 0.024) compared with very low elastase concentration (< 100 microg/l). A high elastase concentration (290-1000 microg/l) was associated with higher ROS index compared with low elastase concentration (1.28 versus 1.01, P=0.016). Slightly increased leukocytes and elastase are associated with slightly poorer sperm characteristics and/or increased sperm necrosis, DNA denaturation and intracellular ROS and decreased MMP.

Sperm nuclear histone H2B: correlation with sperm DNA denaturation and DNA stainability

To examine the relationship between sperm DNA damage and sperm nuclear histone (H2B) staining. We evaluated sperm samples from 14 consecutive asthenoteratozoospermic infertile men and six consecutive fertile controls. Sperm nuclear histone (H2B) staining and sperm chromatin integrity (assessed by sperm chromatin structure assay and expressed using the percentage of (i) DNA fragmentation index [% DFI] and (ii) high DNA stainability [% HDS)]) were evaluated. Histone H2B immunocytochemistry demonstrated two nuclear staining patterns: (i) focal punctate staining; and (ii) diffuse staining. Infertile men had a higher mean percentage of spermatozoa exhibiting diffuse H2B staining than did fertile men (7.7% +/- 4.6% vs. 1.6% +/- 1.2%, respectively, P < 0.01). We observed significant relationships between the proportion of spermatozoa with diffuse nuclear histone staining and both sperm % DFI (r = 0.63, P < 0.01) and sperm %HDS (r = 0.63, P < 0.01). The data demonstrate that infertile men have a higher proportion of spermatozoa with diffuse histone H2B than do fertile men and suggest that sperm DNA damage might, at least in part, be due to abnormally high histone H2B levels.

Effect of smoking on blood lead levels in workers and role of reactive oxygen species in lead-induced sperm chromatin DNA damage

To investigate whether cigarette smoking affects the blood lead levels (BLL) and whether exposure to lead introduces sperm chromatin DNA damage in factory workers. Cross-sectional study. A battery plant in Taiwan. Eighty male workers employed within a battery plant. Standard semen analysis was performed according to the World Health Organization guidelines. Assessment of BLL, sperm chromatin DNA structure, reactive oxygen species generation and other conventional parameters of semen quality. As compared with nonsmoking workers, the BLL were found to be considerably higher among smokers. Statistically significant differences were found in the sperm DNA denaturation (alphaT) induction and the percentage of sperm with increased DNA denaturation (COMP alphaT) in workers with moderate BLL (>or=25 microg/dL). After adjustment for smoking propensity, a positive correlation was discernible between BLL and alphaT, COMP alphaT, and morphologic abnormality. Furthermore, alphaT and COMP alphaT were also found to have positive correlations with sperm superoxide anion production. Workers with higher BLL were found to be at a higher risk of sperm morphologic abnormality and chromatin DNA integrity. These data are significant because they can facilitate the estimation of lead exposure in reproductive toxicology.

Beneficial Effect of Microsurgical Varicocelectomy on Human Sperm DNA Integrity

No AccessJournal of UrologyUrological Survey: Male Infertility1 Nov 2005Beneficial Effect of Microsurgical Varicocelectomy on Human Sperm DNA Integrity Craig NiederbergerM.D. Craig NiederbergerCraig Niederberger More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(01)68854-2AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "Beneficial Effect of Microsurgical Varicocelectomy on Human Sperm DNA Integrity." The Journal of Urology, 174(5), p. 1943 © 2005 by American Urological Association, Inc.FiguresReferencesRelatedDetails Volume 174Issue 5November 2005Page: 1943 Advertisement Copyright & Permissions© 2005 by American Urological Association, Inc.MetricsAuthor Information Craig Niederberger More articles by this author Expand All Advertisement PDF DownloadLoading ...

Potential adverse effect of sperm DNA damage on embryo quality after ICSI

Sperm DNA damage is prevalent amongst infertile men and has been shown to strongly impact adversely natural reproduction, intrauterine insemination-assisted reproduction and to a lesser degree IVF/ICSI fertilization. The objective of this study was to examine further the relationship between sperm DNA denaturation (DD) and reproductive outcomes after ICSI. We evaluated infertile couples (n = 60) undergoing IVF/ICSI at a single centre. Sperm DD was assessed by flow cytometry analysis of Acridine Orange-treated sperm and expressed as the percentage of sperm with DD. Couples were sub-grouped according to sperm DD results: group 1: 0-15%; group 2: >15-30%; group 3: >30%. There were no differences between the three groups with regard to maternal age, sperm parameters, oocyte maturation, fertilization or pregnancy rates. Group 3 had a significantly higher rate of multinucleation among the embryo cohorts compared to either groups 1 or 2 (20% versus 10% and 8% respectively, P = 0.04). There was a statistically insignificant trend toward an increased spontaneous pregnancy loss rate in group 3 (P =0.50). Although we did not observe significant relationships between sperm DNA damage and either fertilization or pregnancy rates, the potential adverse effect of sperm DNA damage on embryo quality and spontaneous pregnancy loss is concerning.

Beneficial effect of microsurgical varicocelectomy on human sperm DNA integrity

Human sperm DNA damage may adversely affect reproductive outcomes, and the spermatozoa of infertile men possess substantially more DNA damage than that of fertile men. To date, there is no available treatment for men with high levels of sperm DNA damage. The objective of this study was to examine the effect of varicocelectomy on sperm DNA denaturation (DD, an index of sperm DNA damage) in infertile men with a clinical varicocele. We reviewed the reports of 37 men who underwent microsurgical varicocelectomy at our institution from September 2001 to July 2002. Standard semen parameters and the percentage of spermatozoa with DD (monitored by flow cytometry analysis of acridine orange-treated spermatozoa) were assessed before and 6 months after varicocelectomy. The percentage of spermatozoa with DD decreased following varicocelectomy compared with pre-operatively (27.7 versus 24.6%, respectively, P < 0.05). Sperm concentration and the percentages of motile sperm and normal forms (WHO criteria) increased following varicocelectomy, but the difference did not reach statistical significance. Our data suggest that varicocelectomy can improve human sperm DNA integrity in infertile men with varicocele. These data represent the first report of improved sperm DNA integrity after therapy and further support the beneficial effect of varicocelectomy on human spermatogenesis.

Human sperm DNA integrity: correlation with sperm cytoplasmic droplets

Objectives To examine the retention of sperm cytoplasmic droplets (CD) and DNA denaturation (DD) in semen from fertile and infertile men. Methods Semen samples were obtained from consecutive nonazoospermic men presenting for infertility evaluation (n = 101) and fertile men presenting for vasectomy (n = 13). The standard semen parameters (sperm concentration, motility, and morphology), sperm DD, and sperm CD were monitored. Sperm DD was evaluated by flow cytometry analysis of acridine orange-treated spermatozoa and expressed as the percentage of spermatozoa demonstrating denatured DNA. Results The mean (±SE) percentages of spermatozoa with CD and DD were significantly higher in infertile than in fertile men (sperm CD 15.7% ± 0.8% versus 4.8% ± 0.7% and sperm DD 22.0% ± 1.5% versus 10.8% ± 1.8%, respectively). Sperm CD and DD were positively correlated ( r = 0.59). Also, sperm CD and DD values correlated inversely with the standard semen parameters. Conclusions Our data demonstrate that the retention of sperm CD correlates positively with sperm DD and that significantly higher sperm DD and CD are found in infertile than in fertile men. These data suggest that the enhanced susceptibility of sperm DNA to denaturation is associated with the abnormal disposal of residual sperm cytoplasm in the testis and/or epididymis.

Prevalence of abnormal sperm DNA denaturation in fertile and infertile men

Objectives To examine the prevalence of abnormal sperm DNA denaturation (DD), a marker of sperm DNA integrity, in a group of fertile and infertile men. Methods Eighty-eight nonazoospermic, infertile men and 13 fertile men underwent standard semen analysis and acridine orange sperm DNA integrity studies. Standard semen parameters (sperm concentration, motility, and morphology) and sperm DNA integrity (expressed as the percentage of spermatozoa with DD) were measured. Results Of the 88 infertile men, 13 had completely normal semen parameters and the remaining 75 had at least one abnormal semen parameter. The mean (±SE) sperm DD level was significantly lower in the population of infertile men with normal semen parameters compared with those having abnormal parameters (11.1% ± 3.7% versus 23.1% ± 1.8%, respectively, P <0.001). Only 1 (8%) of the 13 men with normal semen parameters had elevated sperm DD (greater than 30%, verified on two separate analyses) compared with 13 (17%) of the 75 infertile men with abnormal semen parameters ( P >0.05). None of the fertile controls had elevated sperm DD. We observed significant inverse correlations between the sperm DD and sperm motility, morphology, and concentration ( P <0.001). Conclusions Our data show that sperm DD negatively correlates with standard semen parameters and that an isolated abnormality of sperm DD, a marker of sperm DNA integrity, is uncommon in infertile men. Additional studies are needed to support the notion that isolated abnormalities of sperm DNA integrity may represent a new diagnosis for men with unexplained infertility.