In vitro and in vivo androgen regulation of Dendropanax morbiferus leaf extract on late-onset hypogonadism.

Late-onset hypogonadism (LOH) is associated with advancing age and is caused by a deficiency in serum testosterone levels. The aim of this study was to examine the effect of a Dendropanax morbiferus H.Lév. leaf extract (DME) on LOH using TM3 cells and aging male rats as in vitro and in vivo models, respectively. The in vitro effects of DME on testosterone levels and 3ß-hydroxysteroid dehydrogenase (3ß-HSD) protein expression in TM3 cells were analyzed. In the in vivo experiments, DME was orally administered to rats at three doses (50, 100, and 200 mg/kg/day) for 4 weeks. DME significantly increased the testosterone levels and 3ß-HSD protein expression in TM3 cells. The DME groups showed significantly increased levels of androgenic hormones such as testosterone and dehydroepiandrosterone sulfate. The sex hormone-binding globulin production was significantly lower in the DME groups than that in the control group, while the neurohormone levels in the hypothalamic-pituitary-gonadal axis markedly increased. No significant differences were observed in the glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, and prostate-specific antigen levels among the DME and control groups. The triglyceride and low-density lipoprotein cholesterol levels were significantly lower, while the high-density lipoprotein cholesterol levels were significantly higher in the DME groups than those in the control group. The latency time in the rotarod, treadmill, and swimming tests increased with the DME treatment. Furthermore, the sperm counts in the epididymis markedly increased. These results suggest that DME can be effectively used to alleviate the symptoms of LOH.

Reproductive toxic potential of panmasala in male Swiss albino mice.

Some ingredients of panmasala have the ability to penetrate the blood-testis barrier but the reproductive toxic potential of panmasala has not been studied. This study is aimed to assess the possible damage caused by panmasala to male reproductive system in mice. Swiss albino male mice were randomly divided into 7 groups receiving either standard control diet or panmasala-containing diet. Three doses (0.5%, 1.5% and 3%) of panmasala plain (PMP) as well as panmasala with tobacco (PMT)-gutkha were given for a period of 6 months. Assessment of organ weight, sperm count and morphology, spermatid count, sperm production, testicular 17ß-hydroxysteroid dehydrogenase (17ß-HSD) activity and histology were conducted. A nonsignificant decrease in absolute and relative weight of testis and epididymis was observed. Spermatid count, sperm count and production were significantly decreased and 17ß-HSD activity was found considerably declined at 3% of both PMP- and PMT-treated groups as compared to control. The histological observations revealed panmasala induced testicular damage. Abnormal morphology of sperm head shape was significantly elevated in higher doses of both types of panmasala-treated groups than control. The results suggests that panmasala has reproductive toxic potential and more alteration is seen with gutkha as compared to panmasala plain, indicating that similar effects might also be possible in humans.

Effects of leaf extract of Stephania hernandifolia on testicular gametogenesis and androgenesis in albino rats: a dose-dependent response study.

The present study was undertaken to evaluate the dose-dependent effects of a leaf extract of Stephania hernandifolia on testicular activities in albino rats. Whether this leaf extract has any toxic effect on metabolic organs or on the liver or kidney was studied. Adult male Wistar rats, maintained under standard laboratory conditions, were forcefully fed with the aqueous extract of these leaves at the dose of 2 g or 4 g of leaves/mL distilled water/100 g body weight/day for 28 days. All the animals, along with vehicle-treated controls, were killed on the Day 29 of the experiment. Treatment with this leaf extract at both doses resulted in significant reduction in relative weight in the testis, the seminal vesicles, the prostate, and the epididymis without any significant change in the liver and kidney weight in comparison to control. Activities of testicular steroidogenic key enzymes and plasma testosterone level were decreased significantly, along with a significant reduction in the number of germ cells at stage VII of the spermatogenic cycle and in the seminiferous tubular diameter in both treated groups in comparison to control. Activities of glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, acid phosphatase, and alkaline phosphatase were not altered significantly in the liver and kidney in both treated groups compared with controls. We concluded that treatment with an aqueous extract of leaves resulted in diminution in the activities of testicular androgenic key enzymes and plasma level of testosterone along with inhibition of spermatogenesis without any induction of hepatic and renal toxicity.

Localization of type 5 17beta-hydroxysteroid dehydrogenase, 3beta-hydroxysteroid dehydrogenase, and androgen receptor in the human prostate by in situ hybridization and immunocytochemistry.

An important source of androgens in the human prostate are those synthesized locally from the inactive adrenal precursor dehydroepiandrosterone (DHEA) and its sulfated derivative DHEA-S. Three beta-HSD (hydroxysteroid dehydrogenase) converts DHEA into androstenedione (4-dione), whereas type 5 17beta-HSD catalyzes the reduction of 4-dione into testosterone in the human prostate and other peripheral intracrine tissues. In the present study, we have used two complementary approaches, namely in situ hybridization and immunocytochemistry, to identify the cells that contain the type 5 17beta-HSD messenger RNA and enzyme in human benign prostatic hyperplasia (BPH). Localization of 3beta-HSD and of the androgen receptor (AR) was also investigated by immunostaining in the same tissue. To find out whether there are any differences between BPH and normal prostate tissue, the localization of type 5 17beta-HSD was reexamined by immunocytochemistry in the normal human prostate samples and also in normal prostate epithelial cell line (PrEC). The in situ hybridization results obtained with a tritiated uridine triphosphate (3H-UTP)-labeled type 5 17beta-HSD riboprobe are in agreement with the immunostaining data obtained with a specific antibody to the enzyme. The immunostaining results obtained from normal prostate tissue and BPH were found to be similar. Thus, in the glandular epithelium, basal cells highly express the messenger RNA and the enzyme, whereas luminal cells show a much lower and variable level of expression. In the stroma and walls of blood vessels, fibroblasts and the endothelial cells lining the blood vessels show positive staining. Similar results are observed when the cellular distribution of 3beta-HSD is investigated. AR immunoreactivity, however, shows a different distribution because, in the epithelium, most of the nuclei of basal cells are negative, whereas the majority of nuclei of the luminal cells show positive staining. A strong reaction for AR is also found in most stromal cell nuclei and in the nuclei of most endothelial cells, as well as in some other cells of the walls of blood vessels. In conclusion, human type 5 17beta-HSD, as well as 3beta-HSD, are highly expressed, not only in the basal epithelial cells and stromal fibroblasts but also in the endothelial cells and fibroblasts of the blood vessels. AR, on the other hand, is highly expressed in the luminal cells. The present data suggest that DHEA is transformed in the basal cells of the glandular epithelium into 4-dione by 3beta-HSD and then into testosterone by type 5 17beta-HSD, whereas dihydrotestosterone is synthesized in the luminal cells after diffusion of testosterone from the underlying layer of basal cells. The potential role of androgen formation and action in blood vessels is unknown and opens new avenues of investigation for a better understanding of the multiple roles of androgens.

Cloning of rat 17 beta-hydroxysteroid dehydrogenase type 2 and characterization of tissue distribution and catalytic activity of rat type 1 and type 2 enzymes.

17 beta-Hydroxysteroid dehydrogenases (17HSDs) are enzymes catalyzing the conversion between 17 beta-hydroxy- and 17-ketosteroids. Both estrogens and androgens possess their highest activity in the 17 beta-hydroxy form, and the enzymes, therefore, regulate the biological activity of sex hormones. In this study, we have characterized the complementary DNA (cDNA) for rat 17HSD type 2. The cDNA encodes a protein with a predicted mol wt of 42,010 Da. The protein has 77% similarity and 62% identity with the human 17HSD type 2 enzyme. Furthermore, the hydropathicity profiles of the enzymes are very similar. The two isozymes contain a putative transmembrane region close to the N-terminus. However, the rat isozyme lacks the two lysine-rich amino acid cluster present at the N- and C-terminals of human 17HSD type 2. The tissue distribution of the rat 17HSD type 1 and type 2 enzymes is very similar to that of the human enzymes. The highest expression of 17HSD type 2 was detected in the placenta. In addition, a 1.5-kilobase messenger RNA for the enzyme was detected in the small intestine, liver, and kidney of both sexes. The two messenger RNAs for rat 17HSD type 1 (1.4 and 1.7 kilobases) were highly expressed only in the ovary, and at very low concentrations in the kidney of both sexes. Transiently expressed rat 17HSD type 2 showed oxidative activity almost exclusively in cultured human embryonic kidney 293 cells, converting estradiol into estrone and testosterone into androstenedione, whereas the opposite was observed for the rat type 1 enzyme. The data suggest that similarly to the corresponding human isoforms, rat 17HSD type 2 is mostly involved in the oxidation of 17 beta-hydroxysteroids into their relatively inactive keto derivative in peripheral tissues, whereas rat 17HSD type 1 is mainly involved in the glandular biosynthesis of estradiol.

Localization of 17beta-hydroxysteroid dehydrogenase and characterization of testosterone in the brain of the male frog.

Several enzymes involved in the formation of steroids of the pregnene and pregnane series have been identified in the brain, but the biosynthesis of testosterone has never been reported in the central nervous system. In the present study, we have investigated the distribution and bioactivity of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) (EC 1.1.1.62; a key enzyme that is required for the formation of testosterone and estradiol) in the brain of the male frog Rana ridibunda. By using an antiserum against human type I placental 17beta-HSD, immunoreactivity was localized in a discrete group of ependymal glial cells bordering the telencephalic ventricles. HPLC analysis of telencephalon and hypothalamus extracts combined with testosterone radioimmunoassay revealed the existence of two peaks coeluting with testosterone and 5alpha-dihydrotestosterone. After HPLC purification, testosterone was identified by gas chromatography/mass spectrometry. Incubation of telencephalon slices with [3H]pregnenolone resulted in the formation of metabolites which coeluted with progesterone, 17alpha-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone, and 5alpha-dihydrotestosterone. The newly synthesized steroid comigrating with testosterone was selectively immunodetected by using testosterone antibodies. These data indicate that 17beta-HSD is expressed in a subpopulation of gliocytes in the frog telencephalon and that telencephalic cells are capable of synthesizing various androgens, including dehydroepiandrosterone, androstenedione, testosterone, and 5alpha-dihydrotestosterone.

Immunocytochemical localization of type I 17 beta-hydroxysteroid dehydrogenase in the rat brain.

Type I 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) is mainly involved in the reductive transformation of estrone to estradiol. Such a conversion is known to occur in mammalian brain. In order to determine the brain areas and the nerve cell types containing this enzyme, we have proceeded to its immunocytochemical localization in the adult rat brain. Immunoblot analysis showed that the antibodies used could specifically bind to one brain protein band corresponding to purified 17 beta-HSD. Immunolabelled cells were found in high concentration in the hypothalamus, thalamus, hippocampus, cerebral cortex, caudate putamen and pineal gland. At the light microscopic level, 17 beta-HSD immunoreactive material appeared to be present only in glial and ependymal cells, including tanycytes. Double staining procedures showed that the 17 beta-HSD nerve cells also contained glial fibrillary acidic protein (GFAP), a specific marker for glial cells. Immunoelectron microscopic studies demonstrated that immunoreactive material was diffusely distributed throughout the cytoplasm of glial and ependymal cells, thus confirming the association of 17 beta-HSD immunoreactivity with nonneuronal cells. These data suggest that glial cells play an important role in the conversion of a weak estrogen, estrone, to a more potent estrogen, estradiol.

Androgen hydroxysteroid dehydrogenases under the influence of pyridoxine derivatives.

The metabolism of testosterone in the rat ventral prostate, anterior pituitary, basal hypothalamus and amygdala was studied in vitro under the influence of vitamin B6 compounds. The influence of these compounds on the activity of 5 alpha-reductase (5 alpha-R), 3 alpha- and 17 beta-hydroxysteroid dehydrogenase (3 alpha-HSD, 17 beta-HSD) was determined for all the examined tissues. Pyridoxine hydrochloride significantly increased the activity of 5 alpha-R, 3 alpha- and 17 beta-HSD, but pyridoxal hydrochloride had an inhibitory influence on 5 alpha-R and showed no effect on 3 alpha-HSD activity at the prostate level. Male rat anterior pituitary, basal hypothalamus or amygdala incubated with pyridoxal phosphate and pyridoxal hydrochloride showed modified enzymatic activities. Pyridoxal hydrochloride showed an inhibitory effect on 5 alpha-R in the rat pituitary and basal hypothalamus as well as in the rat prostate.