The protective and therapeutic effects of 5-androstene3ß, 17ß-diol (ADIOL) in abdominal post-operative adhesions in rat: Suppressing TLR4/NFκB/HMGB1/TGF1 ß/α SMA pathway.

Neurosteroid, 5-androstenediol (ADIOL) had been experimentally applied to protect against many diseases as it had anti-oxidant, anti-inflammatory, and anti-apoptotic effects. In our study, we investigate its role in abdominal postoperative adhesion (APA) formations. Our results demonstrate that ADIOL alleviates APA formation after induction by cecal abrasion (CA) model in the male rat. Interestingly, per administration of ADIOL before APA induction leads to inhibit oxidative stress by increasing superoxide dismutase (SOD) and decreasing Malondialdehyde (MAD) levels to a similar level to the sham group, in addition inhibiting inflammatory pathway by decreasing toll-like receptor 4 (TLR4), nuclear factor kappa-B (NFκB), and High mobility group box 1 (HMGB1) to a similar level to the sham group, furthermore decreasing Transforming growth factor beta 1 (TGFß1) and alpha Smooth muscle -actin (α SMA) levels to similar levels in the sham group. While administration of ADIOL after APA induction lead to decrease adhesions formation by decreasing oxidative stress (↓MDA and ↑SOD levels), inflammatory markers (↓TLR4, ↓NFκB, and ↓HMGB1levels), and collagen deposition by (↓TGF1 ß and↓α SMA levels) is the highly significant manner to those levels in CA model but also significant to those levels in the sham group. Concluded that, pre-administration of ADIOL before APA induction was more effective than its administration after adhesions formations.

5-Androstenediol prevents radiation injury in mice by promoting NF-κB signaling and inhibiting AIM2 inflammasome activation.

In the present study, the therapeutic effects of 5-androstenediol on radiation-induced myeloid suppression and tissue damage in mice and the possible mechanism were explored. The mice were subjected to whole-body irradiation, and 5-androstenediol was administered subcutaneously at different times and doses. The evaluation of the survival rate showed that the administration of 5-androstenediol every three days post-irradiation was the most effective in decreasing the death of the mice. Additionally, 5-androstenediol dose-dependently reduced the death caused by 9 Gy radiation. The pharmacological mechanism was investigated by blood analysis, western blot analysis, immunofluorescence and immunohistochemistry. 5-Androstenediol significantly ameliorated myeloid suppression, as demonstrated by elevated levels of total white blood cells, including neutrophils and platelets, in the peripheral blood. By H&E staining, we found that radiation-induced myeloid suppression in the bone marrow and spleen, as well as tissue damage in the lung and colon, was significantly ameliorated by treatment with 5-androstenediol. Immunohistochemistry showed elevated phosphorylation of p65 in the bone marrow and spleen, indicating the activation of NF-κB signaling. Moreover, 5-androstenediol markedly hampered the radiation-induced activation of caspase-1 and GSDMD in the colon by decreasing the interaction between AIM2 and ASC. Taken together, our results suggest that, by promoting NF-κB signaling and inhibiting inflammasome-mediated pyroptosis, 5-androstenediol can be used as a radioprotective drug.

The Non-Aromatic Δ5-Androstenediol Derivative of Dehydroepiandrosterone Acts as an Estrogen Agonist in Neonatal Rat Osteoblasts through an Estrogen Receptor α-related Mechanism.

Purpose: It has been proposed that DHEA influences bone formation through, bioconversion to 17ß-estradiol; however, DHEA is converted to Δ5-androstenediol (Δ5-Adiol), a metabolite with estrogenic potential involved in diverse biological process. To gain new insight into the role of Δ5-Adiol in bone cells, we examined DHEA and Δ5-Adiol effects in neonatal rat and human hFOB1.19 osteoblasts. Methods: Osteoblast activity was assessed by analyzing proliferation, alkaline phosphatase activity, and expression of OSX and ALPL. We also examined binding affinities for osteoblast-ER and transcriptional activation of human (h)ERα, hERß or hAR in U2-OS cells. Results: The most striking finding was that Δ5-Adiol had greater stimulatory effect than DHEA on rat osteoblast proliferation and differentiation, as well as ALPL expression in human osteoblasts. Interestingly, the Δ5-Adiol or DHEA-induced effects were not precluded with letrozole or trilostane, consistent with bioconversion of DHEA to Δ5-Adiol due to elevated expression of Hsd17b1 in neonatal rat osteoblasts, suggesting a high level of 17ß-hydroxysteroid dehydrogenase type 1 activity. Conversely, Δ5-Adiol and DHEA-induced proliferative effects were inhibited with ICI 182780 alone or combined with trilostane, which correlates with the higher binding affinity of Δ5-Adiol for ER compared to DHEA. Furthermore, Δ5-Adiol showed a greater relative agonist activity for hERα than for hERß or hAR. Conclusion: This study is the first to show that a bioactive DHEA derivative stimulates E2-dependent osteoblast activities, including proliferation and differentiation in rat and human osteoblasts, through ERα-related mechanisms.

Potential neuroprotective effect of androst-5-ene-3ß, 17ß-diol (ADIOL) on the striatum, and substantia nigra in Parkinson's disease rat model.

Parkinson's disease (PD) is a progressive neurodegenerative disorder with behavioral and motor abnormalities. Androst-5-ene-3ß, 17ß-diol (ADIOL), an estrogen receptor (ER) ß agonist, was found to mediate a transrepressive mechanism that selectively modulates the extent of neuroinflammation and, in turn, neurodegeneration. In consensus, ERß polymorphism was more frequently detected in early-onset PD patients. Thus, in an approach to elucidate the role of ERß agonists on PD, our study was designed to investigate the possible neuroprotective effect of ADIOL, in three dose levels (0.35, 3.5, 35 mg/kg/day), against rotenone (ROT)-induced PD rat model. Amelioration in striatal dopamine (DA), nuclear factor-kappa B (NF-κB), and the expression of down-stream inflammatory mediators, as well as apoptotic markers were observed in the striatum and substantia nigra (SN) upon pre-treatment with the three doses of ADIOL. Similarly, light microscopy (LM) examination revealed declined degeneration of neurons upon pretreatment with ADIOL. Significant improvement in nigral tyrosine hydroxylase (TH) and reduction of nigral α-synuclein densities were also detected after ADIOL pre-treatment with better results frequently achieved with the middle dose (3.5 mg/kg/day). The middle dose of ADIOL showed behavioral improvement, with elevation in the ATP level, which was emphasized by the improvement in mitochondrial integrity observed upon electron microscopy (EM) examination. In conclusion, the present study confirmed for the first time the ability of ADIOL to protect against neuroinflammation and, in turn, neurodegeneration process and motor dysfunction in PD animal model, which was more obviously observed with the middle dose.

Protective Effects of Fetal Zone Steroids Are Comparable to Estradiol in Hyperoxia-Induced Cell Death of Immature Glia.

Impaired neurodevelopment in preterm infants is caused by prematurity itself; however, hypoxia/ischemia, inflammation, and hyperoxia contribute to the extent of impairment. Because preterm birth is accompanied by a dramatic decrease in 17ß-estradiol (E2) and progesterone, preliminary clinical studies have been carried out to substitute these steroids in preterm infants; however, they failed to confirm significantly improved neurologic outcomes. We therefore hypothesized that the persistently high postnatal production of fetal zone steroids [mainly dehydroepiandrosterone (DHEA)] until term could interfere with E2-mediated protection. We investigated whether E2 could reduce hyperoxia-mediated apoptosis in three immature glial cell types and detected the involved receptors. Thereafter, we investigated protection by the fetal zone steroids DHEA, 16α-hydroxy-DHEA, and androstenediol. For DHEA, the involved receptors were evaluated. We examined aromatases, which convert fetal zone steroids into more estrogenic compounds. Finally, cotreatment was compared against single hormone treatment to investigate synergism. In all cell types, E2 and fetal zone steroids resulted in significant dose-dependent protection, whereas the mediating receptors differed. The neuroprotection by fetal zone steroids highly depended on the cell type-specific expression of aromatases, the receptor repertoire, and the potency of the fetal zone steroids toward these receptors. No synergism in fetal zone steroid and E2 cotreatment was detected in two of three cell types. Therefore, E2 supplementation may not be beneficial with respect to neuroprotection because fetal zone steroids circulate in persistently high concentrations until term in preterm infants. Hence, a refined experimental model for preterm infants is required to investigate potential treatments.

Molecular Mechanisms of Androstenediol in the Regulation of the Proliferative Process of Human Endometrial Cells.

Proliferation in endometria of women with polycystic ovarian syndrome (PCOS) is increased, similar to the biosynthesis of androstenediol (estrogenic metabolite). As previously shown, in human endometrial cells, androstenediol increases CYCLIN D1 levels and KI67 and decreases P27 content. The objective of the present investigation was to determine the mechanisms by which androstenediol promotes endometrial cell-cycle progression. Estrogen receptor α (ERα) activation and changes in CYCLIN D1 and P27 levels were evaluated by Western blot in T-HESC and St-T1b endometrial cell lines, using receptor antagonists; activation of PI3K-protein kinase B (AKT) and mitogen-activated protein kinases-extracellular signal-regulated kinases (MAPK-ERK)1/2 pathways was evaluated using PI3K, MAPK/ERK kinase (MEK)1/2, and RNA-polymerase II inhibitors. The data showed that androstenediol treatment significantly increases CYCLIN D1 and decreases P27 levels through ERα activation ( P < .05). In addition, an increase in AKT/ERK1/2 phosphorylations was determined ( P < .05). In the presence of RNA-polymerase II inhibitor, phosphorylation of AKT/ERK1/2 decreased ( P < .05), meaning that endometrial cells need transcriptional activity to activate the kinases involved. It was also observed that PI3K action is required for P27 and CYCLIN D1 changes. Therefore, the action of androstenediol in endometria depends on PI3K-AKT and MAPK-ERK1/2 pathways activation, together with cell transcriptional machinery. This could be of clinical significance, as in pathologies such as PCOS, increased endometrial levels of androstenediol together with a high prevalence of endometrial hyperplasia and adenocarcinoma have been reported.

Medical Countermeasures for Radiation Exposure and Related Injuries: Characterization of Medicines, FDA-Approval Status and Inclusion into the Strategic National Stockpile.

World events over the past decade have highlighted the threat of nuclear terrorism as well as an urgent need to develop radiation countermeasures for acute radiation exposures and subsequent bodily injuries. An increased probability of radiological or nuclear incidents due to detonation of nuclear weapons by terrorists, sabotage of nuclear facilities, dispersal and exposure to radioactive materials, and accidents provides the basis for such enhanced radiation exposure risks for civilian populations. Although the search for suitable radiation countermeasures for radiation-associated injuries was initiated more than half a century ago, no safe and effective radiation countermeasure for the most severe of these injuries, namely acute radiation syndrome (ARS), has been approved by the United States Food and Drug Administration (FDA). The dearth of FDA-approved radiation countermeasures has prompted intensified research for a new generation of radiation countermeasures. In this communication, the authors have listed and reviewed the status of radiation countermeasures that are currently available for use, or those that might be used for exceptional nuclear/radiological contingencies, plus a limited few medicines that show early promise but still remain experimental in nature and unauthorized for human use by the FDA.

The promyelinating properties of androstenediol in gliotoxin-induced demyelination in rat corpus callosum.

AIMS: Experimental evidence has shown that the adrenal steroid hormone, androstenediol, dampens the symptoms of demyelination. However, the cellular and molecular effects of androstenediol are not yet known. In the present study, we investigated the cellular and subcellular effects of this hormone in a gliotoxin-induced demyelination model. METHODS: Male Sprague Dawley rats received 2 µl of either saline or the gliotoxin ethidium bromide (EB, 0.04%) into the corpus callosum. These rats received daily subcutaneous injections of either oil or androstenediol (5 mg/kg). Their brains were collected at 2, 7, 14 and 28 days post-EB injection. Demyelinated lesions were assessed using Luxol fast blue staining. Immunofluorescent staining was used to investigate the number of oligodendrocyte progenitor cells, their maturation and microglial activation at the lesion site. Remyelination was further explored using transmission electron microscopy. The expression levels of total and phosphorylated MBP isoforms and CNPase were explored using western blot. RESULTS: Androstenediol decreased the size of demyelinated lesions in the corpus callosum at 7 and 14 days post-EB injection. It enhanced the number of oligodendrocyte precursor cells, promoted an increase in the number of mature oligodendrocytes and reduced microglial activation. Androstenediol also stimulated the phosphorylation of MBP at the site of the lesion and promoted remyelination of the affected axons. CONCLUSIONS: These data strongly suggest that androstenediol is endowed with promyelinating properties in a model of focal gliotoxin-induced demyelination. It induces its promyelinating effects by enhancing the number of oligodendrocyte precursor cells and their maturation at the lesion site.

A study of the effect of sequential injection of 5-androstenediol on irradiation-induced myelosuppression in mice.

Herein, we aimed at examining the therapeutic effects of 5-androstenediol (5-AED), a natural hormone produced in the adrenal cortex, on radiation-induced myelosuppression in C3H/HeN mice. The mice were subjected to whole-body irradiation with a sublethal dose of 5 Gy gamma-irradiation to induce severe myelosuppression, and 5-AED (50 mg/kg) was administered subcutaneously. 5-AED was administrated 1 day before irradiation (pre-treatment) or twice weekly for 3 weeks starting from 1 h after irradiation (post-treatment). Treatment with 5-AED significantly ameliorated the decrease in the peripheral blood neutrophil and platelet populations in irradiated myelosuppressive mice, but had no effect on the lymphocyte population. It also ameliorated hypocellularity and disruption of bone marrow induced by irradiation and led to rapid recovery of myeloid cells. Further, it attenuated the decrease in spleen weight and megakaryocyte and myeloid cell populations in the spleen and promoted multilineage hematopoietic recovery. We found that a single injection of 5-AED produced only a temporary therapeutic effect, while sequential injection of 5-AED after irradiation had a more pronounced and prolonged therapeutic effect and reduced myelosuppression by irradiation. Thus, sequential injection of 5-AED after irradiation has therapeutic potential for radiation-induced myelosuppression when administered continuously and can be a significant therapeutic candidate for the management of acute radiation syndrome, particularly in a mass casualty scenario where rapid and economic intervention is important.

Androstenediol modulates sepsis induced alterations of survival and immune functions in a murine model of sepsis.

BACKGROUND: Recently the benefit of subcutaneously applied dehydroepiandrosterone (DHEA) during sepsis was demonstrated. It was therefore supposed that the impact of DHEA might be induced by its metabolite androstenediol produced via conversion in subcutaneous tissue. Thus we postulate a comparable impact of intravenously applied androstenediol like DHEA. MATERIAL AND METHODS: Male NMRI mice were subjected to sham-operation (laparotomy) or sepsis (cecal ligation and puncture). Animals received saline, DHEA (20 mg/kg/day) subcutaneously, androstenediol (20 mg/kg/day) subcutaneously and androstenediol (10 mg/kg/day) intravenously. During 48 h of sepsis and treatment clinical parameters such as survival and body temperature were observed. Termination of animals was performed 48 hrs after induction of sepsis in order to monitor splenocyte apoptosis (Annexin V binding capacity), cytokine release (IL-10 and TNF-α, ELISA), and immunological capacity by DTH-Reaction (Delayed type of hypersensitivity). RESULTS: Subcutaneous and intravenous androstenediol administration improved the survival rate of septic mice 48 hrs after induction of CLP like subcutaneous administration of DHEA. (86% vs 53%). This effect was paralleled by a restoration of splenocyte proliferation and DTH reaction, a decreased cellular apoptosis rate of splenocytes, and an attenuation of cytokine release. CONCLUSIONS: Administration of androstenediol induces an increased survival rate and improved cellular immune functions in septic mice. This effect was detected independent of the way of administration and is comparable to those effects induced by subcutaneous DHEA administration. With respect to clinical use during critical illness, intravenous administration of androstenediol seems to be an alternative to subcutaneous DHEA administration.

What are the physiological estrogens?

Estradiol (E2) is the principal physiological estrogen in mammals. E2 and its active metabolites, estrone and estriol have a characteristic phenolic A ring, unlike progesterone, testosterone, cortisol and aldosterone, which have an A ring containing a C3-ketone, a Δ(4) bond and a C19 methyl group. Crystal structures of E2 in the estrogen receptor (ER) confirm the importance of the A ring in stabilizing E2 in the ER. However, other steroids, including Δ(5)-androstenediol, 5α-androstanediol and 27-hydroxycholesterol, which have a saturated A ring containing a 3ß-hydroxyl and a C19 methyl group, also mediate physiological responses through binding to estrogen receptor-α (ERα) and ERß. Moreover, selective estrogen response modulators (SERMs) with diverse structures also regulate transcription of ERα and ERß. Our understanding of the physiological responses mediated by these "alternative" estrogens is in its infancy. Further studies of the role of these steroids and SERMs in regulating responses mediated by ERα and ERß a variety of tissues, during different stages of development, are likely to uncover additional estrogenic activities.

DHEA metabolites activate estrogen receptors alpha and beta.

Dehydroepiandrosterone (DHEA) levels were reported to associate with increased breast cancer risk in postmenopausal women, but some carcinogen-induced rat mammary tumor studies question this claim. The purpose of this study was to determine how DHEA and its metabolites affect estrogen receptors α or ß (ERα or ERß)-regulated gene transcription and cell proliferation. In transiently transfected HEK-293 cells, androstenediol, DHEA, and DHEA-S activated ERα. In ERß transfected HepG2 cells, androstenedione, DHEA, androstenediol, and 7-oxo DHEA stimulated reporter activity. ER antagonists ICI 182,780 (fulvestrant) and 4-hydroxytamoxifen, general P450 inhibitor miconazole, and aromatase inhibitor exemestane inhibited activation by DHEA or metabolites in transfected cells. ERß-selective antagonist R,R-THC (R,R-cis-diethyl tetrahydrochrysene) inhibited DHEA and DHEA metabolite transcriptional activity in ERß-transfected cells. Expression of endogenous estrogen-regulated genes: pS2, progesterone receptor, cathepsin D1, and nuclear respiratory factor-1 was increased by DHEA and its metabolites in an ER-subtype, gene, and cell-specific manner. DHEA metabolites, but not DHEA, competed with 17ß-estradiol for ERα and ERß binding and stimulated MCF-7 cell proliferation, demonstrating that DHEA metabolites interact directly with ERα and ERßin vitro, modulating estrogen target genes in vivo.

17α-androstenediol-mediated oncophagy of tumor cells by different mechanisms is determined by the target tumor.

Δ5-androstene-3ß,17α-diol (17α-AED) mediates oncophagy of human myeloid, glioma, and breast tumor cells by apoptotic- and autophagic-programmed cell death pathways, whereas the 17ß-epimer does not. In hematologically derived myeloid tumor cells, 17α-AED induced apoptosis, as determined by TUNEL staining, caspase, PARP activation, and electron microscopy. In contrast, 17α-AED treatment of glioma cells of neuroectodermal lineaged induced autophagy, evident by the presence of acidic vesicular organelles, LC3 processing, and upregulation of beclin-1. Proliferation inhibition studies on primary and established glioma cells demonstrated that the IC-50 of the steroid is ∼15 µM. In the case of breast cancer cells, the bioactivity of 17α-AED is independent of the expression of estrogen or androgen receptors. Collectively, oncophagy is induced by 17α-AED treatment in human tumor cells and proceeds by the induction of either autophagy or apoptosis. The neoplastic cell determines which oncophagic pathway is utilized.

5-Androstene-3ß,17ß-diol promotes recovery of immature hematopoietic cells following myelosuppressive radiation and synergizes with thrombopoietin.

PURPOSE: 5-Androstene-3ß,17ß-diol (5-AED) stimulates recovery of hematopoiesis after exposure to radiation. To elucidate its cellular targets, the effects of 5-AED alone and in combination with (pegylated) granulocyte colony-stimulating factor and thrombopoietin (TPO) on immature hematopoietic progenitor cells were evaluated following total body irradiation. METHODS AND MATERIALS: BALB/c mice were exposed to radiation delivered as a single or as a fractionated dose, and recovery of bone marrow progenitors and peripheral blood parameters was assessed. RESULTS: BALB/c mice treated with 5-AED displayed accelerated multilineage blood cell recovery and elevated bone marrow (BM) cellularity and numbers of progenitor cells. The spleen colony-forming unit (CFU-S) assay, representing the life-saving short-term repopulating cells in BM of irradiated donor mice revealed that combined treatment with 5-AED plus TPO resulted in a 20.1-fold increase in CFU-S relative to that of placebo controls, and a 3.7 and 3.1-fold increase in comparison to 5-AED and TPO, whereas no effect was seen of Peg-G-CSF with or without 5-AED. Contrary to TPO, 5-AED also stimulated reconstitution of the more immature marrow repopulating (MRA) cells. CONCLUSIONS: 5-AED potently counteracts the hematopoietic effects of radiation-induced myelosuppression and promotes multilineage reconstitution by stimulating immature bone marrow cells in a pattern distinct from, but synergistic with TPO.

Effects of CYP7B1-related steroids on androgen receptor activation in different cell lines.

The widely expressed steroid hydroxylase CYP7B1 is involved in metabolism of a number of steroids reported to influence estrogen and androgen signaling. Several studies by us and other investigators have linked this enzyme to effects on estrogen receptor activation. In a previous report we examined the effect of CYP7B1-mediated hormone metabolism for estrogen-mediated response in kidney-derived HEK293 cells. In the current study we used an androgen response element (ARE) reporter system to examine androgen-dependent response of some CYP7B1 substrates and CYP7B1-formed metabolites in several cell lines derived from different tissues. The results indicate significantly lower androgen receptor activation by CYP7B1-formed steroid metabolites than by the corresponding steroid substrates, suggesting that CYP7B1-mediated catalysis may decrease some androgenic responses. Thus, CYP7B1-dependent metabolism may be of importance not only for estrogenic signaling but also for androgenic. This finding, that CYP7B1 activity may be a regulator of androgenic signaling by converting AR ligands into less active metabolites, is also supported by real-time RT-PCR experiment where a CYP7B1 substrate, but not the corresponding product, was able to stimulate known androgen-sensitive genes. Furthermore, our data indicate that the effects of some steroids on hormone response element reporter systems are cell line-specific. For instance, despite transfection of the same reporter systems, 5-androstene-3ß,17ß-diol strongly activates an androgen-dependent response element in prostate cancer cells whereas it elicits only ER-dependent responses in kidney HEK293 cells. Potential roles of cell-specific metabolism or comodulator expression for the observed differences are discussed.

Beta androstenediol mitigates the damage of 1 GeV/n Fe ion particle radiation to the hematopoietic system.

Space exploration is associated with exposure to 1-3 Gy solar particle radiation and galactic cosmic radiation that could increase cancer rates. Effective nontoxic countermeasures to high linear energy transfer (LET) radiation exposure are highly desirable but currently not available. The aim was to determine whether a single subcutaneous injection of androstenediol (Δ(5) androsten-3ß, 17ß-diol [AED]) could mitigate and restore the mouse hematopoetic system from the radiation-mediated injury of 3 Gy whole-body high LET (56)Fe(26+) exposure. The findings show that postradiation AED treatment has an overall positive and significant beneficial effect to restore the levels of hematopoeitic elements (p<0.001). Androstenediol treatment significantly increased monocyte levels at days 4, 7, and 14 and, similarly, increased red blood cell, hemoglobin, and platelet counts. Flow cytometry analysis 14 days after radiation and AED treatment demonstrated an increase (p<0.05) in bone marrow cells counts. Ex vivo osteoclastogenesis studies show that AED treatment is necessary and advantageous for the development and restoration of osteoclastogenesis after radiation exposure. These findings clearly show that androstenediol functions as a countermeasure to remedy hematopoeitic injury mediated by high LET iron ion radiation. Presently, no other agent has been shown to have such properties.

Hydroxylation of DHEA, androstenediol and epiandrosterone by Mortierella isabellina AM212. Evidence indicating that both constitutive and inducible hydroxylases catalyze 7α- as well as 7ß-hydroxylations of 5-ene substrates.

The course of transformation of DHEA, androstenediol and epiandrosterone in Mortierella isabellina AM212 culture was investigated. The mentioned substrates underwent effective hydroxylation; 5-ene substrates--DHEA and androstenediol--were transformed into a mixture of 7α- and 7ß- allyl alcohols, while epiandrosterone was converted into 7α- (mainly), 11α- and 9α- monohydroxy derivatives. Ketoconazole and cycloheximide inhibition studies suggest the presence of constitutive and substrate-induced hydroxylases in M. isabellina. On the basis of time course analysis of the hydroxylation of DHEA and androstenediol, the oxidation of allyl C(7)-H(α) and C(7)-H(ß) bonds by the same enzyme is a reasonable assumption.

Comparison of the effects of dietary protein, androstenediol and forearm muscle area on radial bone variables in healthy prepubertal children.

Adequate dietary habits are supposed to be one of the most important modifiable factors in osteoporosis prevention. However, the importance of specific nutrients is controversial. We examined relevant nutrients which are supposed to have an impact on bone parameters and compared their effect sizes with those of two known predictors of bone development: bone-related muscle mass and androgen levels. We analysed nutritional, hormonal and anthropometric data from 107 prepubertal children participating in the Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Diaphyseal bone mineral content (BMC), cortical area (CA), periosteal circumference, strength strain index and muscle area of the non-dominant forearm were measured by peripheral quantitative computed tomography. Data on long-term nutrient intakes (e.g. protein, Ca and vitamin D) were derived from 3 d weighed dietary records. Twenty-four hour urinary excretion rates of androgen metabolites including the sex steroid androstenediol were measured using GC-MS. Of all considered nutrients, only protein showed a trend for an association with BMC (ß = +0·11; P = 0·073) and CA (ß = +0·11; P = 0·056) in stepwise linear regression models. None of the other considered dietary variables was associated with bone parameters. The size of the bone anabolic effect of protein was partly comparable with that of androstenediol. Even though boys gained more bone mass in comparison with girls, the protein effect did not differ between sexes. Bone-related muscle area and sex steroids have the strongest effects on prepubertal diaphyseal bone. However, dietary protein may have a similar bone anabolic influence compared with androstenediol. In children without explicit nutrient deficits, protein seems to be the most important dietary component for diaphyseal bone status.

Androstenediol reverses steroid-inhibited wound healing.

It is well recognized that stress of any nature will cause a delay in the wound healing response. This delayed healing response appears closely associated with immune regulators. In this study, CD-1 mice were injected with a long acting form of methyl prednisolone to cause a steroid-induced immune suppression. After 24 hours, two 6-mm full thickness wounds were placed on the animals' backs and one group of animals received the immune-regulating hormone, androstenediol. Wound contraction was quantified by planimetry for the subsequent 14 days. Animals that were stressed with methyl prednisolone but receiving androstenediol contracted their open wounds at faster rates compared with methyl prednisolone-stressed animals treated with the vehicle alone. These findings suggest that restoration of immune regulation by androstenediol can reverse the delayed open wound contraction secondary to steroid stress.

Inhibition of androstenediol-dependent LNCaP tumour growth by 17alpha-ethynyl-5alpha-androstane-3alpha, 17beta-diol (HE3235).

Androst-5-ene-3beta, 17beta-diol (AED) is an adrenal hormone that has been reported to sustain prostate cancer growth after androgen deprivation therapy (ADT). LNCaP cells express a mutated androgen receptor that confers the ability to respond not only to androgen but also to oestrogen and adrenal hormones such as AED, and thus provide a cell line useful for identifying compounds capable of inhibiting AED-stimulated cell growth. We sought to determine whether structurally related steroids could inhibit AED-stimulated LNCaP cell growth in vitro and tumour growth in vivo. We report here the identification of a novel androstane steroid, HE3235 (17alpha-ethynyl-5alpha-androstan-3alpha, 17beta-diol), with significant inhibitory activity for AED-stimulated LNCaP proliferation. This inhibitory activity is accompanied by an increase in the number of apoptotic cells. Animal studies have confirmed the cytoreductive activity of HE3235 on LNCaP tumours. The results suggest that this compound may be of clinical use in castration-resistant prostate cancer.