Male reproductive process is regulated by intricately balanced mechanisms involving the hypothalamus-pituitary-testis axis and accessory sex organs. It is believed that for initiation as well as maintenance of spermatogenesis in humans, both FSH and testosterone are needed. The gonadotropin-releasing hormone (GnRH) secreted by the hypothalamus regulates the synthesis and release of FSH and LH from the pituitary. FSH acts on the Sertoli cells, which are located within the seminiferous tubules in close proximity of developing germ cells, and stimulates production of various proteins including inhibin, androgen-binding protein (ABP), aromatase, anti-Mullerian hormone (AMH), etc. The LH acts on the Leydig cells located in the intertubular space and stimulates production of testosterone. Intratesticular testosterone concentration in humans is about 200-300 times higher than that in peripheral circulation. Testosterone has profound influence on germ cell development and differentiation. It exerts a negative feedback action on LH secretion, and also on FSH (at higher concentration) acting on hypothalamic-pituitary axis.[
13]
Results of the present study clearly show that tulsi treatment (2 g/day) brings about a reduction in sperm count, which is in agreement with the earlier reports. Khanna
et al, have reported significant decrease in sperm count and motility as well as decrease in the weight of testes, epididymis, seminal vesicle, and ventral prostate after long-term feeding of OS leaves.[
14] The long-term feeding of fresh tulsi leaves (465 mg/kg/day) have shown to increase the body weight, while decrease the weights of testes, prostate, and adrenal gland in rats. The results suggested that infertility in male rats seems to be due to impairment of spermatogenesis as well as changes like decrease in pH, hypotonic environment, and chemical substances like mucoproteins, alkaline phosphatase and acid phosphatase in spermatogenic cells leading to formation of non-viable spermatozoa.[
15] However, Seth
et al, reported that benzene extract of OS leaves significantly altered the weight of testes but did not have any significant effect on epididymis, seminal vesicle, prostate, and vas deferens.[
16] Treatment with OS leaves led to a highly significant increase in testosterone levels. FSH and LH levels also showed a significant decrease in the test group after tulsi treatment. A possible hypothesis to explain this pattern of changes in hormone levels could be that tulsi leaves probably contain some androgenic analogue, which increased the circulating testosterone levels sufficiently to inhibit LH but not sufficient to accumulate in the testis at the required concentration for normal spermatogenesis. However, the decreased LH levels will diminish intratesticular production of testosterone by Leydig cells, which results in reduced levels of spermatogenesis. For suppression of spermatogenesis, different androgens and progestins have been used either alone or in combination. Reddy and Rao administered testosterone propionate 100 mg daily intramuscularly to normal volunteers and achieved azoospermia in 100% subjects.[
17] Weekly IM injections of 200 mg testosterone enanthate given to 399 normal healthy fertile males produced azoospermia or severe oligospermia (sperm density <3 million/ml) in more than 95% volunteers. This contraceptive effect was comparable to female contraceptive pills, and was reversible.[
18]
It can thus be concluded that antispermatogenic effect of OS is brought about by modulation of levels of reproductive hormones. Since this is a preliminary study, further studies are required to establish the role of OS as an effective herbal male contraceptive.
This article has been 