Effects of male accessory sex glands on sperm decondensation and oocyte activation during in vivo fertilization in golden hamsters

The relevance of the use of plant extracts on testicular cells: A systematic review

This review aims to establish an association between traditional and scientific knowledge to allow the evaluation of the effectiveness of medicinal plants, as well as their risks based on the testicular microenvironment. A systematic search was performed using PRISMA guidelines. The descriptors were structured based on search filters built for three domains: Animals, Plants, and Testis. The filters on the PubMed/Medline platform were constructed using a hierarchical distribution of the MeSH Terms. Methodological quality assessments were performed using the SYRCLE risk bias tool. Data on testicular cells, hormones and biochemistry, sperm, and sexual behavior were evaluated and compared. The search came out with 2644 articles, and 36 articles met the inclusion criteria and were used in this review. The included studies analyzed testicular cells from murine models treated with crude plant extracts. Plant extracts act directly on the hypothalamic-pituitary axis and/or directly on testicular cells, inhibiting and stimulating the reproductive process, thus causing alterations in fertility rates. Apiaceae and the Cucurbitaceae families are the most used in male reproductive biology experiments, being Apiaceae described as sexual stimulants, while Cucurbitaceae are the main sources of deleterious effects on the male reproductive system.

How bad is brazilian ginseng extract for reproductive parameters in mice?

Properties attributed to the Panax ginseng are also attributed to the Brazilian ginseng, such as adaptogenic and aphrodisiac effects. There are studies demonstrating that the Brazilian ginseng (BGE) possibly increases the serum levels of testosterone and nitric oxide in mice and rats. The present study aimed to evaluate the effects of its extract on male fertility and sperm quality. Male Swiss mice (n = 60) were divided into six groups. The control animals were provided 0.5 mL of water, and 0.5 mL of water containing 7 mg/kg per day (d) sildenafil citrate. Other animals were treated with BGE at 100 mg/kg/d, 200 mg/kg/d, and 400 mg/kg/d by gavage for 42 days. Finally, animals from the last group received 200 mg/kg BGE every 3 days (3-3d) by gavage for 42 days. The results showed a reduction in the number of resistant spermatids in the testis and damage to daily sperm production, culminating in a reduction in the number of epididymal spermatozoa. Although the sperm quality decreased in all experimental animals, only males treated with BGE 100 mg/kg/d showed pre and post implantation embryo losses. We concluded that BGE alters sperm viability compromising the embryonic development after implantation.

Seminal fluid and reproduction: much more than previously thought

The influence of seminal plasma on the cytokine and immune uterine environment is well characterised in mice and humans, while the effects of disruption to uterine seminal plasma exposure on pregnancy and offspring health is becoming more clearly understood. The cellular and molecular environment of the uterus during the pre- and peri-implantation period of early pregnancy is critical for implantation success and optimal foetal and placental development. Perturbations to this environment not only have consequences for the success of pregnancy and neonatal health and viability, but can also drive adverse health outcomes in the offspring after birth, particularly the development of metabolic disorders such as obesity, hypertension and insulin resistance. It is now reported that an absence of seminal plasma at conception in mice promotes increased fat accumulation, altered metabolism and hypertension in offspring. The evidence reviewed here demonstrates that seminal plasma is not simply a transport medium for sperm, but acts also as a key regulator of the female tract environment providing optimal support for the developing embryo and benefiting future health of offspring.

Effects of sperm DNA damage on the levels of RAD51 and p53 proteins in zygotes and 2-cell embryos sired by golden hamsters without the major accessory sex glands

We previously reported that the male accessory sex gland (ASG) secretion is the main source of antioxidants to safeguard sperm genomic integrity and functional competence. Removal of all ASGs in the golden hamster can reduce male fertility by increasing embryo wastage. This study aims to investigate whether the oxidative DNA-damaged sperm from hamsters without all ASGs (TX) could successfully fertilize oocytes and to qualify the status of DNA repair by the expression of RAD51 and p53 proteins. Here we demonstrated a significantly higher DNA-base adduct formation (8-hydroxy-2'-deoxyguanosine) in sperm from TX males than those from sham-operated males. Comet assays demonstrated that all female pronuclei in both zygotes were intact, but single- and double-strand DNA damage was found in decondensed sperm in TX males only. DNA damage could also be detected in both nuclei of the TX 2-cell embryos. RAD51, a DNA repair enzyme, was found to be evenly distributed in the cytoplasm and nuclei in oocytes/zygotes, while at the 2-cell stage, a strong expression of p53 protein and a larger clear perinuclear area without RAD51 expression were found in TX embryos. In conclusion, we demonstrated for the first time DNA damage in decondensed sperm of zygotes and blastomeres of 2-cell stage embryos sired by TX males, resulting in the activation of DNA repair. Sperm DNA damage could induce the increase in p53 expression and the reduction of RAD51 expression in the TX 2-cell stage embryos.

Ablation of paternal accessory sex glands imparts physical and behavioural abnormalities to the progeny: an in vivo study in the golden hamster

The functional significance of male accessory sex glands (ASG) remains unclear. This study explored their importance in reproduction. In previous investigations, embryos sired by males with ASG either totally or partially removed had a shift in the cell cycle and delayed cleavage during preimplantation development, higher incidence of apoptosis, early oviductal-uterine transit, higher proportion of embryo degeneration, lower implantation rate, and ultimately reduced fertility and fecundity. Some pups were born alive; but would they be normal? We hypothesized that the first generation offspring (F1) could also bear undesirable traits. To test our hypothesis, we raised and studied these F1 pups from birth to 8 weeks. We monitored physical growth and assessed behaviour such as nest patch odor preference, acoustic startle response (ASR) and exploratory activity. We detected deviations from the norm in physical growth, a premature cessation of nest patch odor preferences, accelerated acoustic startle habituation and more frequent rearing when exposed to a novel environment. In terms of structure, we found one incidence of diphallus with duplicated urethra. We concluded that sperm lacking contact with ASG secretions gave rise to progeny with abnormal traits.

Male genital tract antioxidant enzymes--their ability to preserve sperm DNA integrity

Male germ cells are unique because they lose a bulk of their cytoplasm as cytoplasmic droplets when they develop, leading to a decrease in endogenous antioxidant and hence a dependence on extracellular antioxidant system to overcome oxidative stress. Spermatozoa are particularly vulnerable to oxidative stress because their plasma membrane is rich in polyunsaturated fatty acids and membrane-bound NADPH oxidase. To protect spermatozoa from oxidative attack, an optimal amount of reactive oxygen species is maintained by balancing the reactive oxygen species generated during sperm maturation in the epididymidis and antioxidants in secretions of the male reproductive tract. The male accessory sex glands secretions have been shown to be the major source of antioxidant enzymes in the ejaculate and have the important function of preserving sperm DNA integrity from oxidative stress experienced in the uterine environment. In our in vivo golden hamster model, ablation of the five major male accessory sex glands, namely the ampullary glands, coagulating glands, dorsolateral prostate, ventral prostate and seminal vesicle, was found to cause higher incidence and greater degree of DNA damage in spermatozoa. These damaged sperm are able to undergo fertilization at the same rate as intact ones; however, the outcome of embryos sired is seriously affected.

Male genital tract antioxidant enzymes: their source, function in the female, and ability to preserve sperm DNA integrity in the golden hamster

Recently, we reported that male accessory sex gland (ASG) secretions protect sperm genomic integrity by demonstrating that DNA damage was more extensive in sperm not exposed to the secretions. The present study was conducted to find out if ASGs secrete the main antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx or GSH-Px), and catalase (CAT) and if the most abundant one, SOD, can protect those sperm that were not exposed to ASG secretions against NADPH-induced oxidative stress. Four experimental groups of male golden hamsters were used: intact animals with proven fertility, animals with all major ASGs removed (TX), animals that were bilaterally vasectomized, and sham-operated controls. SOD, CAT, and GPx activities were measured in secretions from all 5 ASGs and sperm-free uterine flushing from virgin females and those mated with the experimental males. The alkaline comet assay was used to analyze DNA integrity of the TX group sperm after incubation in a medium containing 50 U/mL of SOD along with 0 to 20 mmol/L NADPH. The main antioxidant enzyme in ASGs was SOD from coagulating glands (P <.05) and GPx together with CAT from ampullary glands (P <.05). Uterine flushing of ejaculates that contained ASG secretions had more SOD and CAT activities than those with epididymal secretions alone (P <.05 and P <.001, respectively), whereas activity of GPx was the same (P >.05). Addition of SOD in vitro dose dependently decreased the incidence of single-strand DNA damage in sperm not exposed to ASG secretions incubated in the presence of 0 to 20 mmol/L NADPH (P <.001). These results indicated that, in terms of abundance, SOD was the main antioxidant enzyme secreted by male ASGs, whereas CAT was the second one. The GPx activity came from both epididymis and ASGs. We conclude that ASG secretions play a significant role in protecting sperm against oxidative stress.

The effect of FIV infection on CD4+ and CD8+ counts in periradicular lesions

AIM

The purpose of this study was to elucidate whether a decrease/increase in T-cell populations is present in the development of periradicular disease in the immunocompromised feline model.

METHODOLOGY

Eight cats were immunosuppressed with steroids prior to infection with feline immunodeficiency virus (FIV). Another eight cats, age and sex matched littermates, were monitored and tested at equivalent periods of time and served as uninoculated, seronegative controls. Periradicular lesions were induced using local bacterial inoculations into the pulp of the canine teeth and assessed after one- and four-week periods, corresponding to the acute and chronic stages of the periradicular disease. Block sections were obtained and specimens were prepared for H & E and immunohistochemical staining for CD4+ and CD8+ receptors. Cells were quantified using a computer imaging system and data analysed using generalized estimating equation (GEE) regression models.

RESULTS

Significantly lower CD4+ counts and CD4+/ CD8+ ratios were observed at all time periods in the periradicular region of the FIV group (P = 0.0006). No significant difference in CD8+ counts was observed between the two groups. In both groups there was a significant difference in the CD4+ counts between one week and baseline, and 1 week and 4 weeks. There was no significant difference between baseline and 4 weeks for either group.

CONCLUSION

FIV infection reflected decreased CD4+ counts at the periradicular level, however, inflammation and progression of the lesion, appeared to be comparable to the non-immunocompromised controls.