Postnatal ontogeny of Neuromedin S and its receptors NMUR1 and NMUR2 expression in mouse testis.

Neuromedin S (NMS) is a well-known anorexigenic neuropeptide. Despite some reports of the presence of its transcript and precursor protein in testis, the expression and localization of NMS and its receptors during the postnatal development of mammalian testis remains elusive. We investigated the expression patterns and testicular localization of NMS and its receptors NMUR1 and NMUR2, during 5, 10, 20, 30, and 90 days of postnatal development, using real time PCR, immunoblot analysis and immunohistochemistry in mice. NMS and its receptors are present at all age groups at transcript level in mouse testis. At the protein level, NMS and NMUR2 are present in all age groups, whereas NMUR1 is present primarily in 30- and 90-day testis. Immunolocalization study showed that NMS and NMUR2 are expressed in spermatogonia, spermatocytes, Sertoli cells, and Leydig cells, in contrast to NMUR1 which is expressed exclusively in the Leydig cells of 30- and 90-day testis. The results also confirm the intranuclear localization of NMS in spermatogonia and spermatocytes. Although NMS-NMUR2 is expressed in Sertoli cells at all stages of the spermatogenic cycle, they showed a stage-specific expression pattern in spermatogonia and primary spermatocytes. In conclusion, NMS and its receptors NMUR1 and NMUR2 are expressed in the testis and may regulate spermatogenesis, possibly by modulating steroidogenesis and Sertoli cell function in the testis.

Sub-Chronic Restraint Stress Suppresses Sexual Potency and Erection Efficiency by Targeting the Hypothalamic-Pituitary-Testicular Axis and the Nitric Oxide/Cyclic Guanosine Monophosphate/Phosphodiesterase 5α Pathway in Adult Rats.

INTRODUCTION: Male sexual potency and vigor are a complex neuroendocrine process and an important component of well-being. Psychological stress is one of the leading causes of male impotence worldwide. Therefore, to better understand the effects of psychological stress on male sexual potency, vigor, and the physiology of erection, we used the rat restraint stress (RS) model, which can most aptly simulate psychological stress. METHODS: Adult male SD rats were exposed to RS for 1.5 or 3 h/day for 30 days. Neuromodulators and hormones of sexual potency and penile erection were quantified using ELISA kit. The histoarchitecture of the penis was examined using Masson trichrome staining. Immunoblotting and immunofluorescence were used to assess the expression and immunolocalization patterns of penile erection markers. To assess sexual potency and vigor, a noncontact erection and a copulatory test were performed. RESULTS: RS exposure decreased the circulatory levels of gonadotropins and testosterone while increasing the serum corticosterone level. RS exposure altered the histomorphology of the penis by decreasing the smooth muscle/collagen ratio and increasing oxidative stress in penile tissue. Furthermore, RS adversely affected NO availability for penile erection by decreasing the neurotransmitter acetylcholine and other erection facilitatory markers such as p-Akt, nNOS, eNOS, and cGMP, while increasing the inhibitory marker PDE5α in the penis. RS exposure significantly reduced the frequencies of mount, intromission, and ejaculation, whereas it prolonged sexual exhaustion by increasing latencies of postejaculatory mount, intromission, and ejaculation. CONCLUSION: The current findings suggest that psychological stressors, such as RS, cause erectile dysfunction in adult male rats by modulating the hypothalamic-pituitary-testicular axis, oxidative balance, penile fibrosis, and the NO/cGMP/PDE5α pathway of penile erection.

Sub-chronic restraint stress exposure in adult rats: An insight into possible inhibitory mechanism on testicular function in relation to germ cell dynamics.

Psychological stress is now widely recognized as one of the major risk factors for male fertility. Its impact on the dynamics of testicular germ cells, however, has yet to be fully investigated. Therefore, we used the rat restraint stress (RS) model as a psychological stressor to assess the impact of psychological stress on testicular germ cell dynamics. Adult male SD rats were exposed to sub-chronic RS for 1.5 and 3 h per day for 30 days. The quality of cauda epididymis spermatozoa was adversely affected by RS exposure, and the frequency of spermatozoa with tail abnormalities was higher than that of spermatozoa with head abnormalities. RS exposure adversely affected testicular daily sperm production by disturbing the meiotic and post meiotic germ cell kinetics in the testis. The histomorphology of the testis was altered by loosening and vacuolization in the seminiferous epithelium, germ cell exfoliation and the presence of giant cells. Seminiferous tubules of stage I-VI and VII-VIII were severely affected in rats exposed to RS for 3 h. By interfering with steroidogenic enzymes, RS exposure disrupts testosterone biosynthesis. The testicular oxidative balance was also disturbed by RS exposure, which disrupted the levels/activities of lipid peroxidation, Nrf-2, superoxide dismutase and catalase. There was also an increase in caspase-3 activity and a decrease in the Bax-Bcl2 ratio. In conclusion, our findings suggest that psychological stressors like RS impair testicular functions in rats by disrupting germ cell dynamics, downregulating testicular androgenesis and increasing oxidative stress and apoptosis.

Profertility effects of Shilajit on cadmium-induced infertility in male mice.

Shilajit is claimed as a Vajikarak (aphrodisiac) and used for the treatment of male infertility by traditional healers of the Indian subcontinent. Therefore, the present investigation was designed to assess the effectiveness of Shilajit for treatment of male infertility resulting from exposure to perilous chemicals. Effect of daily oral administration (p.o.) of Shilajit (50 mg, 100 mg and 200 mg/Kg BW) was investigated for a single spermatogenic cycle (35 days) in cadmium-induced (2 mg/Kg BW, p.o. for 35 days) infertile adult (12-14 week) swiss male mice. Shilajit treatment increased weights of reproductive organs, testicular daily sperm production, activities of testicular Δ5 3ß-HSD and 17 ß-HSD enzymes and serum level of testosterone. Histopathological evaluation of testis revealed that Shilajit restored spermatogenesis as reflected by a gradual augmentation in germ cell layers with increased doses of Shilajit compared to cadmium-treated mice. Further, Shilajit treatment reverted back the adverse effects of cadmium on motility and concentration of spermatozoa. Secretory activities of the epididymis and seminal vesicle and libido, fertility and the number of litters per female were also improved by Shilajit in cadmium-treated mice. Results thus suggest the potent androgenic nature of Shilajit and its role in fertility improvement against cadmium-induced infertility.

Natural products in regulation of male fertility.

Medicinal plants may prove useful in developing plant-based strategies for regulation of male fertility. The present review describes the antifertility potential of certain medicinal plants, viz. Azadirachta indica, Curcuma longa, Allamanda cathartica and Bacopa monnieri in Parkes (P) male mice. The results suggested that treatment with the aqueous extracts of these plants caused reversible suppression of spermatogenesis and fertility in P mice and that there were no signs of detectable toxicity in treated mice. Further research needs to be done to develop plant-based strategies for control of male fertility.

Reproductive effects of lipid soluble components of Syzygium aromaticum flower bud in male mice.

BACKGROUND: The flower buds of Syzygium aromaticum (clove) have been used in indigenous medicines for the treatment of male sexual disorders in Indian subcontinent. OBJECTIVE: To evaluate the effect of Syzygium aromaticum flower bud on male reproduction, using Parkes (P) strain mice as animal model. MATERIALS AND METHODS: Mice were orally administered lipid soluble components of Syzygium aromaticum flower bud in doses of 15, 30, and 60 mg/kg body weight for 35 days, and several male reproductive endpoints were evaluated. RESULTS: Treatment with lower dose (15 mg) of Syzygium increased the motility of sperm and stimulated the secretory activities of epididymis and seminal vesicle, while higher doses (30 and 60 mg) had adverse effects on sperm dynamics of cauda epididymidis and on the secretory activities of epididymis and seminal vesicle. Libido was not affected in treated males; however, a significant decrease in litter in females sired by males treated with higher doses of Syzygium was recorded. CONCLUSION: Treatment with Syzygium aromaticum flower bud causes dose-dependent biphasic effect on male reproductive indices in P mice; lower dose of Syzygium appears stimulatory, while the higher doses have adverse effect on male reproduction. The results suggest that the lower dose of Syzygium may have androgenic effect, but further studies are needed to support this contention.

Antispermatogenic and antifertility effects of fruits of Piper nigrum L. in mice.

Effect of oral administration (25 and 100 mg/kg body wt/day, for 20 and 90 days) of fruit powder of Piper nigrum L. on the male reproductive organs of mice, Parkes strain, was investigated. Various reproductive end points such as organs weight, histopathology, sperm parameters, sialic acid and fructose contents, and fertility indices were assessed. Histologically, testes in treated mice, except in those treated with 100 mg of dose for 90 days, showed non-uniform degenerative changes in the seminiferous tubules, as both affected and normal tubules were observed in the same section. In mice treated with 100 mg dose for 90 days, degenerative changes were observed in all the tubules. Affected seminiferous tubules showed intraepithelial vacuolation, loosening of germinal epithelium, occurrence of giant cells, and mixing of spermatids of different stages of spermatogenesis; in severe cases, the tubules were lined by mainly a layer of Sertoli cells. Percentage of affected tubules in testes of Piper-treated mice was dose-and duration-related. Further, Piper nigrum treatment for 20 days did not cause appreciable alterations in histological appearance of the epididymis, while the treatment for 90 days caused detectable alterations in the duct. The treatment also had adverse effects on sperm parameters, levels of sialic acid and fructose, and on litter size. Fifty six days after cessation of treatment, the alterations induced in the reproductive organs recovered to control levels, though the litter size in females impregnated by Piper-treated males remained significantly decreased compared to controls.

Reversible antifertility effect of aqueous rhizome extract of Curcuma longa L. in male laboratory mice.

BACKGROUND: The purpose of the present study was to evaluate the antifertility potential of Curcuma longa L. in the male laboratory mouse. STUDY DESIGN: Mice of the Parkes (P) strain were orally administered aqueous rhizome extract of C. longa (600 mg/kg body weight per day for 56 and 84 days), and effect of the treatment on various male reproductive endpoints and fertility was evaluated. Recovery studies were also performed. RESULTS: Histologically, testes in mice treated with the plant extract showed nonuniform degenerative changes in the seminiferous tubules as both affected and normal tubules were observed in the same section; the affected tubules showed loosening of germinal epithelium, intraepithelial vacuolation and mixing of spermatids of different stages of spermatogenesis. Marked reductions in diameter of seminiferous tubules, height of germinal epithelium and number of germ cells in Stage VII tubules were also noted in testes of extract-treated mice. Epididymis and seminal vesicle also showed histological alterations. Furthermore, the treatment had adverse effects on motility, viability, morphology and number of spermatozoa in the cauda epididymidis, levels of sialic acid in the epididymis and fructose in the seminal vesicle, serum level of testosterone and on fertility and litter size. By 56 days of treatment withdrawal, however, the above parameters recovered to control levels. CONCLUSIONS: The results show that in P mice C. longa treatment causes reversible suppression of spermatogenesis and fertility, thereby suggesting the potential of this plant in the regulation of male fertility.

Safety assessment of Syzygium aromaticum flower bud (clove) extract with respect to testicular function in mice.

The flower buds of Syzygium aromaticum (clove), a common food flavor, have been used as indigenous medicine for the treatment of male sexual disorders in Asian countries. However, the possible mechanism(s) by which it acts at testicular level remain obscure. Therefore, to investigate its effect on testicular function, chronic oral exposure of hexane extract of flower buds of Syzygium aromaticum in three doses (15 mg, 30 mg, and 60 mg/kg BW) were evaluated for a single spermatogenic cycle (35 days) in Parkes (P) strain mice. The treatment did not induce systemic toxicity at the doses tested. Lower dose (15 mg) of the extract increased the activities of Delta(5) 3 beta-HSD and 17 beta-HSD, and serum level of testosterone. The higher doses (30 and 60 mg) of extract inhibited these parameters and induced non-uniform degenerative changes in the seminiferous tubules associated with decrease in daily sperm production and depletion of 1C (round and elongated spermatids) population. Taken together these results suggest biphasic action of hexane extract of Syzygium aromaticum flower bud on testicular function, thereby advocating a cautious use of the flower bud as an aphrodisiac in indigenous systems of medicine in Asian countries.

Effect of aqueous leaf extract of Azadirachta indica on the reproductive organs in male mice.

Effect of oral administration (50, 100, and 200 mg/kg body weight/day, for 28 days) of aqucous leaf extract of neem (Azadirachta indica) on the male reproductive organs of the Parkes (P) strain mice was investigated. The treatment had no effect on body weight and the reproductive organs weight. In treated mice, testes showed both normal and affected seminiferous tubules in the same sections; the affected seminiferous tubules showed intraepithelial vacuolation, loosening of germinal epithelium, marginal condensation of chromatin in round spermatids, occurrence of giant cells, mixing of germ cell types in stages of spermatogenesis and degenerated appearance of germ cells. In severe cases, the tubules were lined with Sertoli cells only, Sertoli cells and rare germ cells, or with Sertoli cells and several germ cells but without cellular association patterns. Also, the frequency of affected seminiferous tubules in testes of the extract-treated mice was significantly higher than the controls, though this remained unaffected in mice treated at 50 mg/kg body weight of the extract. Doses at 50 or 100 mg/kg body weight of neem leaf extract did not cause appreciable alterations in histological appearance of the epididymis, while a dose of 200 mg/kg body weight caused marked alterations both in histological appearance and the level of sialic acid in the duct. The treatment also had adverse effects on motility, morphology, and number of spermatozoa in the cauda epididymidis, level of fructose in the seminal vesicle, and on litter size. After 42 days of withdrawal of the treatment, the alterations induced in the reproductive organs recovered to control levels. Our results suggested that treatment with neem leaf extract caused reversible alterations in the male reproductive organs of P mice.