Ergosteroids. II: Biologically active metabolites and synthetic derivatives of dehydroepiandrosterone

A systematic review of the impact of 7-keto-DHEA on body weight

7-Keto-DHEA has been commercially advertised as a dietary supplement to support weight loss. The objective of the present systematic review it to summarize the evidence supporting the use of 7-keto-DHEA in overweight and obese population. The systematic search was conducted in Medline, Embase, Cochrane Library, CINAHL, Web of Science, Scopus, ICTRP, and ClinicalTrials.gov. Additionally, reference lists of eligible studies were considered, and authors of relevant studies were contacted. Two authors independently screened the studies against the inclusion criteria and assessed their risk of bias. In total, 4 out of 686 studies were included in the review. They all held a low risk of bias. Half of them showed a significant reduction in body weight. One study found a decrease in body fat percentage and another one reported a decrease in BMI. Two studies stated an increase in resting metabolic rate. No serious adverse effects were reported. Various possible mechanisms in favor of weight loss are discussed; however, with the evidence currently available, no clear answer can be given regarding 7-keto-DHEA and weight loss. Further studies need to be conducted to clarify the efficacy and safety of this drug before it can be recommended for therapeutic use.

7-oxo-DHEA enhances impaired M. tuberculosis-specific T cell responses during HIV-TB coinfection

BACKGROUND

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB), affecting approximately one third of the world's population. Development of an adequate immune response will determine disease progression or progress to chronic infection. Risk of developing TB among human immunodeficiency virus (HIV)-coinfected patients (HIV-TB) is 20-30 times higher than those without HIV infection, and a synergistic interplay between these two pathogens accelerates the decline in immunological functions. TB treatment in HIV-TB coinfected persons is challenging and it has a prolonged duration, mainly due to the immune system failure to provide an adequate support for the therapy. Therefore, we aimed to study the role of the hormone 7-oxo-dehydroepiandrosterone (7-OD) as a modulator of anti-tuberculosis immune responses in the context of HIV-TB coinfection.

METHODS

A cross-sectional study was conducted among HIV-TB patients and healthy donors (HD). We characterized the ex vivo phenotype of CD4 + T cells and also evaluated in vitro antigen-specific responses by Mtb stimulation of peripheral blood mononuclear cells (PBMCs) in the presence or absence of 7-OD. We assessed lymphoproliferative activity, cytokine production and master transcription factor profiles.

RESULTS

Our results show that HIV-TB patients were not able to generate successful anti-tubercular responses in vitro compared to HD, as reduced IFN-γ/IL-10 and IFN-γ/IL-17A ratios were observed. Interestingly, treatment with 7-OD enhanced Th1 responses by increasing Mtb-induced proliferation and the production of IFN-γ and TNF-α over IL-10 levels. Additionally, in vitro Mtb stimulation augmented the frequency of cells with a regulatory phenotype, while 7-OD reduced the proportion of these subsets and induced an increase in CD4 + T-bet+ (Th1) subpopulation, which is associated with clinical data linked to an improved disease outcome.

CONCLUSIONS

We conclude that 7-OD modifies the cytokine balance and the phenotype of CD4 + T cells towards a more favorable profile for mycobacteria control. These results provide new data to delineate novel treatment approaches as co-adjuvant for the treatment of TB.

Changes of BMI, steroid metabolome and psychopathology in patients with anorexia nervosa during hospitalization

Anorexia nervosa (AN) is associated with various alterations including the dysfunction of the HPA axis and consequently the hypercortisolemia and deficit in sex hormones but the comprehensive evaluation of changes in circulating steroids during the hospitalization of AN patients is lacking. We investigated the effect of realimentation of women with AN during hospitalization on 45 circulating steroids, the relationships between BMI, its change during hospitalization and physical activity, on one side and initial levels and their changes for two adipokines, circulating steroids, anorexia-specific (hunger, appetite and satiety), and anorexia non-specific symptoms (anxiety, depression fatigue, sleep, and body pain) on the other side. We included 33 women with anorexia who were hospitalized for 38(35, 44) days (median with quartiles). The increase of BMI from the initial value 15.2 (13.2, 16.6) kg/m² was 1.69 (1.37, 2.66) kg/m². The patients with more severe anorexia showed higher activity in 7β-, and 16α-hydroxylation of androgen precursors, which declined during hospitalization. Otherwise, the 7α-hydroxylation activity is higher in AN patients with less severe malnutrition and the ratio of 5-androstene-3β,7α,17β-triol to 5-androstene-3β,7β,17β-triol increased during the realimentation. Our data allow to speculate that the intensive 7β-, and 16α- and possibly also the 7α-hydroxylation of C19 Δ⁵ steroids participate in the pathophysiology of anorexia by additional catabolism of substrates available for synthesis of active androgens and estrogens. However, the question remains whether the synthetic analogues of 7α/β- and 16α-hydroxy-steroids prevent the catabolism of the sex steroid precursors, or further activate the "energy wasting" mitochondrial thermogenic metabolism.

Activation of Adrenal Steroidogenesis and an Improvement of Mood Balance in Postmenopausal Females after Spa Treatment Based on Physical Activity

Spa treatment can effectively reestablish mood balance in patients with psychiatric disorders. In light of the adrenal gland’s role as a crossroad of psychosomatic medicine, this study evaluated changes in 88 circulating steroids and their relationships with a consolidation of somatic, psychosomatic and psychiatric components from a modified N-5 neurotic questionnaire in 46 postmenopausal 50+ women with anxiety-depressive complaints. The patients underwent a standardized one-month intervention therapy with physical activity and an optimized daily regimen in a spa in the Czech Republic. All participants were on medication with selective serotonin reuptake inhibitors. An increase of adrenal steroidogenesis after intervention indicated a reinstatement of the hypothalamic-pituitary-adrenal axis. The increases of many of these steroids were likely beneficial to patients, including immunoprotective adrenal androgens and their metabolites, neuroactive steroids that stimulate mental activity but protect from excitotoxicity, steroids that suppress pain perception and fear, steroids that consolidate insulin secretion, and steroids that improve xenobiotic clearance. The positive associations between the initial values of neurotic symptoms and their declines after the intervention, as well as between initial adrenal activity and the decline of neurotic symptoms, indicate that neurotic impairment may be alleviated by such therapy provided that the initial adrenal activity is not seriously disrupted.

Synthesis of 3α-deuterated 7α-hydroxy-DHEA and 7-oxo-DHEA and application in LC-MS/MS plasma analysis

7-Oxygenated metabolites of dehydroepiandrosterone (DHEA) are known for their neuroprotective and immunomodulatory properties. These neuroactive steroids are currently predominately analysed by mass spectrometry, for which the use of internal deuterated standards is necessary. The aim of this study was to synthesize the deuterated derivatives of 7α-hydroxy-DHEA and 7-oxo-DHEA and test them in liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to enhance the performance characteristics of this method. Here we report the synthesis of 3α deuterium-labelled 7α-hydroxy-DHEA and 7-oxo-DHEA. Deuterium was introduced into the 3α position by reduction of the corresponding 3-ketone with a protected 17-carbonyl group using NaBD4. Our new procedure allows the easier synthesis of deuterated steroid labelled compounds. The use of these deuterated steroids enabled us to improve the human plasma LC-MS/MS analysis of 7α-hydroxy-DHEA and 7-oxo-DHEA in terms of sensitivity, precision and recovery.

Dehydroepiandrosterone and 7-oxo-dehydroepiandrosterone in male reproductive health: Implications of differential regulation of human Sertoli cells metabolic profile

Dehydroepiandrosterone (DHEA) is a precursor of androgen synthesis whose action is partially exerted through its metabolites. 7-Oxo-dehydroepiandrosterone (7-oxo-DHEA) is a common DHEA metabolite, non-convertible to androgens, which constitutes a promising therapeutic strategy for multiple conditions. Sertoli cells (SCs) are responsible for the support of spermatogenesis, having unique metabolic characteristics strongly modulated by androgens. Consequently, disruptions in androgen synthesis compromise SCs function and hence male fertility. We aimed to evaluate the effects of DHEA and 7-oxo-DHEA in human SCs (hSCs) metabolism and oxidative profile. To do so, hSCs were exposed to increasing concentrations of DHEA and 7-oxo-DHEA (0.025, 1 and 50 μM) that revealed to be non-cytotoxic in these experimental conditions. We measured hSCs metabolites consumption/production by (1)H NMR, the protein expression levels of key players of the glycolytic pathway by Western blot as well as the levels of carbonyl groups, nitration and lipid peroxidation by Slot blot. The obtained data demonstrated that 7-oxo-DHEA is a more potent metabolic modulator than DHEA since it increased hSCs glycolytic flux. DHEA seem to redirect hSCs metabolism to the Krebs cycle, while 7-oxo-DHEA has some inhibitory effect in this path. The highest 7-oxo-DHEA concentrations (1 and 50 μM) also increased lactate production, which is of extreme relevance for the successful progression of spermatogenesis in vivo. None of these steroids altered the intracellular oxidative profile of hSCs, illustrating that, at the concentrations used they do not have pro- nor antioxidant actions in hSCs. Our study represents a further step in the establishment of safe doses of DHEA and 7-oxo-DHEA to hSCs, supporting its possible use in hormonal and non-hormonal therapies against male reproductive problems.

N-Hydroxyphthalimide catalyzed allylic oxidation of steroids with t-butyl hydroperoxide

A new and optimized procedure for the allylic oxidation of Δ(5)-steroids with t-butyl hydroperoxide in the presence of catalytic amounts of N-hydroxyphthalimide (NHPI) under mild conditions was developed, showing excellent regioselectivity and chemoselectivity (functional group compatibility). It was found that Co(OAc)2 could enhance the catalytic ability of NHPI resulting in better yields and shorter reaction times. The reaction mechanism and the scope of the reaction with a variety of Δ(5)-steroidal substrates were also investigated.

A comparison of dehydroepiandrosterone and 7-keto dehydroepiandrosterone with other drugs that modulate ethanol intake in rats responding under a multiple schedule

Dehydroepiandrosterone (DHEA), 7-keto DHEA, and several comparison drugs (ethanol, chlordiazepoxide, rauwolscine, and RO15-4513) were administered to male rats responding under a multiple schedule of food and ethanol presentation to determine their selectivity for decreasing ethanol-maintained responding. DHEA and 7-keto DHEA significantly decreased both ethanol-maintained and food-maintained responding, compared with the control, while also decreasing the blood ethanol concentration (BEC). Acute ethanol administration also decreased responding for both food and ethanol; however, ethanol-maintained responding was more potently decreased than food-maintained responding. BEC remained relatively stable after increasing ethanol doses. Among the other drugs tested, RO15-4513 was the most selective for decreasing ethanol-maintained responding compared with food-maintained responding, and it decreased BECs as ethanol-maintained responding decreased. The largest dose of rauwolscine significantly decreased responding for food, whereas it did not affect ethanol-maintained responding compared with the control. Low to intermediate doses of rauwolscine produced small, nonsignificant increases in ethanol-maintained responding and BECs. Chlordiazepoxide produced significant decreases in food-maintained responding and the dose of ethanol presented, but only at the highest dose tested. Although DHEA and 7-keto DHEA did not decrease ethanol-maintained responding as selectively as ethanol or RO15-4513 under the multiple schedule, these neurosteroids may be valuable pharmacological tools in the development of new treatments for alcohol abuse and dependence.

Neurosteroid Binding Sites on the GABA(A) Receptor Complex as Novel Targets for Therapeutics to Reduce Alcohol Abuse and Dependence

Despite the prevalence of alcohol abuse and dependence in the US and Europe, there are only five approved pharmacotherapies for alcohol dependence. Moreover, these pharmacotherapeutic options have limited clinical utility. The purpose of this paper is to present pertinent literature suggesting that both alcohol and the neurosteroids interact at the GABA_A receptor complex and that the neurosteroid sites on this receptor complex could serve as new targets for the development of novel therapeutics for alcohol abuse. This paper will also present data collected by our laboratory showing that one neurosteroid in particular, dehydroepiandrosterone (DHEA), decreases ethanol intake in rats under a variety of conditions. In the process, we will also mention relevant studies from the literature suggesting that both particular subtypes and subunits of the GABA_A receptor play an important role in mediating the interaction of neurosteroids and ethanol.

Effects of 7-keto dehydroepiandrosterone on voluntary ethanol intake in male rats

Administration of dehydroepiandrosterone (DHEA), a neurosteroid that can negatively modulate the GABA A receptor, has been shown to decrease voluntary intake of ethanol in rats. In vivo, DHEA can be metabolized to a variety of metabolites, including 3β-acetoxyandrost-5-ene-7,17-dione (7-keto DHEA), a metabolite without the prohormonal effects of DHEA. This study compared the effectiveness of 7-keto DHEA with DHEA for reducing ethanol intake in the same group of rats. The subjects, previously trained to drink ethanol using a saccharin-fading procedure, had access to ethanol for 30 min daily and the amount consumed was recorded. Subjects were administered 10 and 56 mg/kg of DHEA or 7-keto DHEA intraperitoneally 15 min before drinking sessions. Subjects received each particular dose daily until one of two criteria was met, that is, either ethanol intake did not differ by more than 20% of the mean for 3 consecutive days or for a maximum of 8 days. Both 10 and 56 mg/kg of 7-keto DHEA significantly reduced the dose of ethanol consumed. Although 10mg/kg of 7-keto DHEA produced decreases similar to those found with DHEA, the 56-mg/kg dose of 7-keto DHEA was significantly more effective at decreasing the dose of ethanol consumed than the same dose of DHEA. These results show that 7-keto DHEA is comparable with, or possibly more effective than, DHEA at decreasing ethanol consumption in rats, and that 7-keto DHEA is a compound deserving further investigation as a possible clinical treatment for alcohol abuse without the prohormonal effects of DHEA.

The effects of DHEA, 3beta-hydroxy-5alpha-androstane-6,17-dione, and 7-amino-DHEA analogues on short term and long term memory in the mouse

Neurosteroids have been reported to modulate memory processes in rodents. Three analogues of dehydroepiandrosterone (DHEA), two of them previously described (7beta-aminoDHEA and 7beta-amino-17-ethylenedioxy-DHEA), and a new one (3beta-hydroxy-5alpha-androstane-6,17-dione) were synthesized, and their effects were evaluated on memory. This study examined their effects on long term and short term memory in male (6 weeks old) NMRI mice in comparison with the reference drug. Long term memory was assessed using the passive avoidance task and short term memory (spatial working memory) using the spontaneous alternation task in a Y maze. Moreover, the effects of DHEA and its analogues on spontaneous locomotion were measured. In all tests, DHEA and analogues were injected at three equimolar doses (0.300-1.350-6.075 microM/kg). DHEA and its three analogues administered immediately post-training at the highest doses (6.075 microM/kg, s.c.) improved retention in passive avoidance test. Without effect per se in the spatial working memory task, the four compounds failed to reverse scopolamine (1mg/kg, i.p.)-induced deficit in spontaneous alternation. These data suggested an action of DHEA and analogues in consolidation of long term memory particularly when emotional components are implied. Moreover, data indicated that pharmacological modulation of DHEA as performed in this study provides derivatives giving the same mnemonic profile than reference molecule.

First synthesis of 7α- and 7β-amino-DHEA, dehydroepiandrosterone (DHEA) analogues and preliminary evaluation of their cytotoxicity on Leydig cells and TM4 Sertoli cells

Efficient syntheses of new DHEA analogues, and their apoptotic and necrotic effects on Leydig cells and TM4 Sertoli cells are described. The key step in the synthetic strategy of 7-amino-DHEA derivatives involves a bromination on C-7 position to give an epimeric mixture of bromides which were substituted by azides and reduced to give 7alpha- and 7beta-amino-3beta-hydroxyandrost-5-en-17-ones. No cytotoxic effect induced by apoptosis mechanism was observed on Leydig and TM4 Sertoli cells by treatment with these amino-DHEA analogues. A necrotic effect was induced only in TM4 Sertoli cells. The best activity was obtained with 7alpha,beta-amino-androst-5-en-3beta-ol and 7beta-amino-3beta-hydroxy-androst-5-en-17-one.

HUM5007, a novel combination of thermogenic compounds, and 3-acetyl-7-oxo-dehydroepiandrosterone: each increases the resting metabolic rate of overweight adults

This study tested the hypothesis that 3-acetyl-7-oxo-dehydroepiandrosterone alone (7-Keto) and in combination with calcium citrate, green tea extract, ascorbic acid, chromium nicotinate and cholecalciferol (HUM5007) will increase the resting metabolic rate (RMR) of overweight subjects maintained on a calorie-restricted diet. In this randomized, double-blind, placebo-controlled, crossover trial, overweight adults on a calorie-restricted diet were randomized to three 7-day treatment periods with 7-Keto, HUM5007 or placebo. Resting metabolic rate was measured by indirect calorimetry at the beginning and end of each treatment period with a 7-day washout between testing periods. Of 45 subjects enrolled, 40 completed the study (30 women, 10 men; mean age, 38.5 years; mean mass index, 32.0 kg/m(2)). During the placebo treatment, RMR decreased by 3.9% (75+/-111 kcal/day; mean+/-S.D.); however, RMR increased significantly by 1.4% (21+/-115 kcal/day) and 3.4% (59+/-118 kcal/day) during the 7-Keto and HUM5007 treatment periods, respectively (each compared to placebo, P=.001). No significant differences were found between the treatment periods with respect to compliance or adverse events. In this study, the administration of HUM5007 or 7-Keto reversed the decrease in RMR normally associated with dieting. HUM5007 and 7-Keto increased RMR above basal levels and may benefit obese individuals with impaired energy expenditure. HUM5007 and 7-Keto were generally well tolerated and no serious adverse events were reported.

Redox reactions of dehydroepiandrosterone and its metabolites in differentiating 3T3-L1 adipocytes: A liquid chromatographic-mass spectrometric study

Dehydroepiandrosterone is known to depress fatty acid formation in differentiating 3T3-L1 adipocytes. The metabolism of dehydroepiandrosterone and four of its natural metabolites in differentiating adipocytes was studied by liquid chromatography-mass spectrometry. Adipocytes rapidly converted dehydroepiandrosterone to androst-5-ene-3beta,17beta-diol. 7alpha-Hydroxy-DHEA was interconverted with 7-oxo-DHEA and 7beta-hydroxy-DHEA and the corresponding 17beta reduced products. Dehydroepiandrosterone and its derivatives were detected only in the culture medium suggesting that dehydroepiandrosterone is metabolized via enzymes located in close proximity to, or that are integral parts of the cell membrane. Alternatively, there may be efficient mechanisms at play for extrusion of the steroids to the aqueous media rather than being retained in the lipid-rich cell. An interesting aspect of the study was finding androstenediol as the major metabolite of dehydroepiandrosterone. Androst-5-ene-3beta,17beta-diol has been implicated in prostate cancer. The contribution of adipose cells to the circulating supply of androst-5-ene-3beta,17beta-diol may therefore be considered in managing prostate cancer.

The identification and simultaneous quantification of 7-hydroxylated metabolites of pregnenolone, dehydroepiandrosterone, 3beta,17beta-androstenediol, and testosterone in human serum using gas chromatography-mass spectrometry

7-Hydroxy-metabolites of dehydroepiandrosterone (DHEA) and 3beta,17beta-androstenediol (AD) possess immunomodulatory and neuroprotective properties; therefore, the measurement of these steroids in patients with autoimmune diseases or disturbances in the CNS may be of interest. A gas chromatography-mass spectrometry (GC-MS) method for the determination of 7-hydroxy-metabolites of pregnenolone, DHEA, AD, and testosterone including the parent steroids was applied to serum samples from 12 adult men (27-66 years), 13 male adolescents (13-20 years), 5 boys (6-10 years), 15 women in the follicular phase of the menstrual cycle (22-45 years), 17 women in the luteal phase (22-45 years), and 4 girls (6-10 years). The steroids were age and sex dependent, but independent of the menstrual cycle. The ratio of the 7alpha-hydroxy-metabolites to their parent steroids were age dependent, exhibiting an increasing trend (p < 0.0001, ANOVA) from pregnenolone (5%) to AD (20%). The ratio of 7beta- to 7alpha-metabolites ranged from 0.6 to 1. These results are consistent with models suggesting 7alpha-hydroxylation of the parent steroid, conversion to a 7-oxo-steroid and finally to the 7beta-hydroxylated-metabolite. Partial correlations suggested that 7-hydroxylation might reduce the concentration of circulating androgens. Despite the three times lower concentration of AD-metabolites, their antiglucocorticoid, immunomodulatory, and neuroprotective effects may be comparable to that of DHEA based on their reported greater biological activity.

Effect of lean system 7 on metabolic rate and body composition

OBJECTIVE

This study evaluated whether a commercial weight-loss product (Lean System 7) would result in less reduction in resting metabolic rate (RMR) in overweight subjects on a calorie-restricted diet and exercise regimen than in subjects using diet and exercise alone.

METHODS

In this randomized, double-blind, placebo-controlled study, healthy overweight adults were given three capsules of a commercial weight-loss product twice daily or an identical placebo and followed a calorie-restricted diet and an exercise program for 8 wk. RMR, body weight, body mass index, waist and hip circumferences, and body composition by dual-energy x-ray absorptiometry were measured at baseline and week 8. An intention-to-treat analysis was performed.

RESULTS

Of 47 adults enrolled, 35 completed the study. Subjects taking the commercial weight-loss product had a significant (P = 0.03) increase in RMR, 7.2% increase versus 0.7% decrease in the placebo group. Subjects taking the commercial weight-loss product also had a significant (P = 0.04) decrease in hip circumference, 3.78 cm versus 2.07 cm in the placebo group. There were no other statistically significant differences in any other outcome variable, diet composition, exercise compliance, or adverse events.

CONCLUSION

The results of this study showed that administration of a commercial weight-loss product to overweight adults in conjunction with a calorie-restricted diet and moderate exercise program effectively reverses the decrease in RMR associated with calorie restriction within this study population. The commercial weight-loss product was well tolerated, and there were no serious adverse events over the 8 wk studied.

C19‐5‐ene Steroids in Nature

Dehydroepiandrosterone (DHEA), produced from cholesterol in the adrenals, is the most abundant steroid in our circulation. It is present almost entirely as the sulfate ester, but the free steroid is the form that serves as a precursor of estrogens and androgens, as well as 7- and 16-oxygenated derivatives. Mammalian tissues reduce the 17-keto Group of DHEA to produce androstenediol-a weak estrogen and full-fledged androgen. Its androgen activity is not inhibited by the anti-androgens commonly used to treat prostate cancer. It is probably responsible for the growth of therapy-resistant prostate cancer. DHEA is hydroxylated at the 7 alpha position, and this derivative is oxidized by 11 beta-hydroxysteroid dehydrogenase to form 7-keto DHEA. The latter is reduced by the same dehydrogenase to form 7 beta-hydroxy DHEA. When fed to rats, each of the latter three steroids induce the formation of two thermogenic enzymes in the liver. The late-term human fetus produces relatively large amounts of 16 alphahydroxy DHEA, which serves the mother as a precursor of estriol.

Bioconversion of 3beta-hydroxy-5-cholenoic acid into chenodeoxycholic acid by rat brain enzyme systems

We have previously demonstrated that the rat brain contains three unconjugated bile acids, and chenodeoxycholic acid (CDCA) is the most abundantly present in a tight protein binding form. The ratio of CDCA to the other acids in rat brain tissue was significantly higher than the ratio in the peripheral blood, indicating a contribution from either a specific uptake mechanism or a biosynthetic pathway for CDCA in rat brain. In this study, we have demonstrated the existence of an enzymatic activity that converts 3beta-hydroxy-5-cholenoic acid into CDCA in rat brain tissue. To distinguish marked compounds from endogenous related compounds, 18O-labeled 3beta-hydroxy-5-cholenoic acid, 3beta,7alpha-dihydroxy-5-cholenoic acid, and 7alpha-hydroxy-3-oxo-4-cholenoic acid were synthesized as substrates for in vitro incubation studies. The results clearly suggest that 3beta-hydroxy-5-cholenoic acid was converted to 3beta,7alpha-dihydroxy-5-cholenoic acid by microsomal enzymes. The 7alpha-hydroxy-3-oxo-4-cholenoic acid was produced from 3beta,7alpha-dihydroxy-5-cholenoic acid by the action of microsomal enzymes, and Delta4-3-oxo acid was converted to CDCA by cytosolic enzymes. These findings indicate the presence of an enzymatic activity that converts 3beta-hydroxy-5-cholenoic acid into CDCA in rat brain tissue. Furthermore, this synthetic pathway for CDCA may relate to the function of 24S-hydroxycholesterol, which plays an important role in cholesterol homeostasis in the body.

The neuroactive steroid 3-alpha-ol-5-beta-pregnan-20-one hemisuccinate, a selective NMDA receptor antagonist improves behavioral performance following spinal cord ischemia

The initial response to an ischemic event is the rapid release of excitatory amino acid's followed by the activation of the "ischemic cascade". It has been suggested that neurosteroids, which act as negative modulators of excitatory amino acid receptors, may improve behavioral functions and promote neuronal survival following ischemia. The present study evaluated the pharmacological effects of 3-alpha-ol-5-beta-pregnan-20-one hemisuccinate (ABHS), a neurosteroid that inhibits excitatory amino acid receptor function, in a rabbit reversible spinal cord ischemia model (RSCIM). ABHS was administered (25 mg/kg) intravenously (i.v.) 5 or 30 min following the start of occlusion to groups of rabbits exposed to ischemia induced by temporary occlusion of the infrarenal aorta. The group P50 represents the duration of ischemia (min) associated with a 50% probability of resultant permanent paraplegia. Quantal analysis indicated that the P50 of the control group was 23.44 +/- 4.32 min. Using the RSCIM, neuroprotection is observed if a drug significantly prolongs the P50 compared to the control group. Treatment with ABHS (25 mg/kg) 5 min post-occlusion significantly (p < 0.05) prolonged the P50 of the group to 49.18 +/- 10.44 min, an increase of 110%. The effect of ABHS was not durable following a single injection since a significant difference between the control and ABHS-treated groups was not measurable at 48 h. However, if ABHS was injected 5 min following the start of ischemia and again 24 h after ischemia, there was a persistent effect of the drug at 48 h. Moreover, ABHS also increased the tolerance to ischemia if administered 30 min following the start of occlusion. Our results suggest that neuroactive steroids such as ABHS, which are selective NMDA receptor antagonists, may have substantial therapeutic benefit for the treatment of ischemic injuries including spinal cord neurodegeneration and stroke.

Mitotic and neurogenic effects of dehydroepiandrosterone (DHEA) on human neural stem cell cultures derived from the fetal cortex

Dehydroepiandrosterone (DHEA) is a neurosteroid with potential effects on neurogenesis and neuronal survival in humans. However, most studies on DHEA have been performed in rodents, and there is little direct evidence for biological effects on the human nervous system. Furthermore, the mechanism of its action is unknown. Here, we show that DHEA significantly increased the growth rates of human neural stem cells derived from the fetal cortex and grown with both epidermal growth factor (EGF) and leukemia inhibitory factor (LIF). However, it had no effect on cultures grown in either factor alone, suggesting a specific action on the EGF/LIF-responsive cell. Precursors of DHEA such as pregnenolone or six of its major metabolites, had no significant effect on proliferation rates. DHEA did not alter the small number (<3%) of newly formed neuroblasts or the large number (>95%) of nestin-positive precursors. However, the number of glial fibrillary acidic protein-positive cells, its mRNA, and protein were significantly increased by DHEA. We found both N-methyl-d-aspartate and sigma 1 antagonists, but not GABA antagonists, could completely eliminate the effects of DHEA on stem cell proliferation. Finally we asked whether the EGF/LIF/DHEA-responsive stem cells had an increased potential for neurogenesis and found a 29% increase in neuronal production when compared to cultures grown in EGF/LIF alone. Together these data suggest that DHEA is involved in the maintenance and division of human neural stem cells. Given the wide availability of this neurosteroid, this finding has important implications for future use.

Antioxidant effects of dehydroepiandrosterone and 7alpha-hydroxy-dehydroepiandrosterone in the rat colon, intestine and liver

This study examined in healthy male Wistar rats the in vivo antioxidant effect of dehydroepiandrosterone (DHEA) and 7alpha-hydroxy-DHEA administered by intraperitoneal injections (50 mg/kg body weight) for 2 or 7 days. Markers of oxidative damage to lipids (thiobarbituric acid-reacting substances, TBARS) and to proteins (protein carbonyls) were assessed in colon, small intestine, and liver homogenates. DHEA and 7alpha-hydroxy-DHEA caused a decrease in body weight. DHEA treatment significantly increased liver, colon, and small intestine cell weights. After 7 days, DHEA exerted an antioxidant effect in all organs studied. In the colon, oxidative damage protection was accompanied by a goblet cell proliferation and increase in acidic mucus production. After 2 days, the antioxidant effect of 7alpha-hydroxy-DHEA was mainly observed in the liver. Nonprotein sulfhydryl groups (mostly glutathione levels) were altered by DHEA in the liver whereas they remained unchanged after 7alpha-hydroxy-DHEA treatment. The results indicate that in healthy animals, DHEA exerts a protective effect, particularly in the colon, by reducing the tissue susceptibility to oxidation of both lipids and proteins. This effect was not limited to a specific tissue, whereas the metabolite 7alpha-hydroxy-DHEA exerted its antioxidant effect towards the two markers of oxidative damage earlier than DHEA, and mainly in the liver.

7-oxo-DHEA and Raynaud's phenomenon

Patients with Raynaud's phenomenon have abnormal digital vasoconstriction in response to cold. The pathogenesis remains unknown but may involve a local neurovascular defect leading to vasoconstriction. Diagnosis of primary Raynaud's phenomenon is based on typical symptomatology coupled with normal physical examination, normal laboratory studies and lack of observable pathology by nail fold capillaroscopy. Secondary Raynaud's phenomenon is known to occur associated with several connective tissue diseases, vascular injury due to repeated vibrational trauma, and other causes which produce demonstrable vascular and microcirculatory damage. Treatment of Raynaud's symptoms is conservative and aimed at prevention of attacks. Patients are advised to remain warm and, if possible, to live in warm climates. We suggest that an ergogenic (thermogenic) steroid, 7-oxo-DHEA (3-acetoxyandrost-5-ene-7,17-dione), which is available without prescription as the trademarked 7-keto DHEA, may be very helpful in prevention of primary Raynaud's attacks by increasing the basal metabolic rate and inhibiting vasospasm.

Synthesis of two new haptens of 16alpha-hydroxydehydroepiandrosterone (3beta,16alpha-dihydroxyandrost-5-en-17-one)

Synthetic routes leading to 19E and 7Z O-(carboxymethyl)oximes derived from 16alpha-hydroxydehydroepiandrosterone were developed using two independent methods for introduction of the 16alpha-hydroxy group. Firstly, the oxime moiety was built, and then, either epoxidation of the enol acetate followed by the boron trifluoride mediated rearrangement or alkaline hydrolysis of the corresponding alpha-bromide in aqueous N,N-dimethylformamide were employed. The last step in both methods was removal of the protecting groups, which consisted of acid deprotection of the acetates and gentle alkaline hydrolysis of the methyl ester. Final haptens were designed as components for immunoanalytical kits.

Transformations of DHEA and its metabolites by rat liver

Because dehydroepiandrosterone (DHEA) has a wide variety of weak beneficial effects in experimental animals and humans, we searched for metabolites of this steroid in the hope of finding more active compounds that might qualify for the title "steroid hormone." Incubation of DHEA with rat liver homogenate fortified with energy-yielding substrates resulted in rapid hydroxylation at the 7alpha-position of the molecule and subsequent conversion to other 7-oxygenated steroids in the sequence DHEA --> 7alpha-hydroxyDHEA --> 7-oxoDHEA --> 7beta-hydroxyDHEA, with branching to diols, triols, and sulfate esters. The ability of these metabolites to induce the formation of liver thermogenic enzyme activity increased from left to right in that sequence. A total of 25 different steroids were characterized, and at least six additional structures that are currently under study were produced from DHEA. 7-OxoDHEA is more effective than DHEA in enhancing memory performance in old mice and in reversing the amnesic effects of scopolamine.

Ergosteroids VII: perchloric acid-induced transformations of 7-oxygenated steroids and their bio-analytical applications--a liquid chromatographic-mass spectrometric study

Sulfate esters of 7-oxo-delta(5)-steroids can be selectively and quantitatively hydrolyzed to the corresponding free steroids in the presence of carboxylic acid esters by solvolysis with perchloric acid in ethyl acetate at room temperature. Sulfates as well as carboxylic acid esters, methyl ethers, and ketals can be quantitatively converted to the corresponding 3,5-diene-7-one derivatives by heating with perchloric acid in methanol at 65 degrees C. The dienes have a strong UV absorption with maximum centered around 284 nm. These reactions have been used for the characterization and structural elucidation of 7-oxygenated-delta(5)-steroids that are present in complex biomatrices and can also be used for the quantitative estimation of total 7-oxo-delta(5)-steroids (free as well as conjugated) in biological matrices.

Analysis of ergosteroids. VIII: Enhancement of signal response of neutral steroidal compounds in liquid chromatographic-electrospray ionization mass spectrometric analysis by mobile phase additives

The signal response of moderately polar to nonpolar neutral steroidal compounds in positive ion mode was significantly improved in electrospray ionization mode by addition of volatile organic acids (trifluoroacetic acid, acetic and formic) at concentrations much lower than those normally employed for high-performance liquid chromatographic separations of ionic compounds. Each of the three acids enhanced the sensitivity, the order being: formic acid (approximately 50-200 ppm, v/v) > acetic acid (100-500 ppm) > trifluoroacetic acid (5-20 ppm). Higher concentrations caused decrease in the sensitivity. The extent of increase in the sensitivity was compound specific and also depended on the nature of organic modifier present in the mobile phase. Acetic acid was the acid of choice for the 'wrong-way-round' ionization of sulfate conjugates. The postcolumn addition of silver nitrate produced highly stable (M + Ag)+ adducts with concomitant increase in signal response and reduction in baseline noise.

Ergosteroids V: preparation and biological activity of various D-ring derivatives in the 7-oxo-dehydroepiandrosterone series

Our previous finding that D-ring seco derivatives of dehydroepiandrosterone retained biologic activity (Reich et al., Steroids 1998;63:542-53) motivated us to synthesize and test a number of steroids in which the D-ring is retained but altered in various ways. Several new steroids were synthesized and characterized by (1)H and (13)C NMR spectroscopy. The availability of a number of closely related compounds allowed detailed (13)C chemical shift correlations. Using the induction of two thermogenic enzymes in rats, liver mitochondrial glycerophosphate dehydrogenase (GPDH) and cytosolic malic enzyme, as criteria of biologic activity some 30 compounds were assayed. Hydroxylation of dehydroepiandrosterone (DHEA) at the 16 alpha position was previously shown to diminish activity (Lardy et al., Steroids 1998;63:158-65); the corresponding 7-oxo compound is fully active. Hydroxylation at the 15 beta position of DHEA, 7-oxo-DHEA, or 16 alpha-hydroxy-7-oxo-DHEA greatly diminished the induction of GPDH but induction of malic enzyme was retained. Most 5,15 diene steroids tested had 2 weak, or no, ability to enhance the formation of GPDH but did increase malic enzyme.

Ergosteroids. VI. Metabolism of dehydroepiandrosterone by rat liver in vitro: a liquid chromatographic-mass spectrometric study

Because relatively large amounts of dehydroepiandrosterone (DHEA) are required to demonstrate its diverse metabolic effects, it is postulated that this steroid may be converted to more active molecules. To search for the possible receptor-recognized hormones. DHEA was incubated with whole rat liver homogenate and metabolite appearances were studied by LC-MS as a function of time to predict the sequence of their formation. An array of metabolites has been resolved, identified and characterized by highly specific and accurate technique of LC-MS, and several of these steroids were analyzed quantitatively. Their identities were established by comparison with pure chemically synthesized compounds and by chemical degradation of isolated fractions. In the present study, we have reasonably established that DHEA was converted to 7alpha-OH-DHEA, 7-oxo-DHEA, and 7beta-OH-DHEA in sequence. These metabolites were further reduced at position 7 and/or 17 to form their respective diols and triols, which were also sulfated at 3beta-position. DHEA and its 7-oxygenated derivatives were also converted to their respective 3beta-sulfate esters. Several of these steroids are being reported for the first time. 16Alpha-hydroxy-DHEA, androst-5-ene-3beta,16alpha,17beta-triol, androst-4-ene-3,17-dione, 11-hydroxy-androst-4-ene-3,17-dione, androst-5-ene-3,17-diol and testosterone were also identified and characterized. In all, 19 metabolites of DHEA are being reported in this extensive study. We have also detected the formation of 12 additional metabolites including several conjugates, which are the subject of current investigation.

Ergosteroids IV: synthesis and biological activity of steroid glucuronosides, ethers, and alkylcarbonates

The 7-oxo derivative of dehydroepiandrosterone is more active than the parent steroid and is devoid of adverse side effects in rats, monkeys and humans. In anticipation of possible therapeutic use we have sought more active, longer lasting forms of 7-oxo- and 7beta-hydroxydehydroepiandrosterones. The 7-oxo- and 7-hydroxy steroids have been converted to glucuronides, ethers and carbonate esters. The syntheses of these compounds are described and their ability to induce the formation of liver thermogenic enzymes when fed to rats is reported. Some of the new derivatives were found to be somewhat more effective than the equimolar amounts of 7-oxo-DHEA with which they were compared in each experiment.

Short-term hypothermia activates hepatic mitochondrial sn-glycerol-3-phosphate dehydrogenase and thermogenic systems

The contribution of the sn-glycerol-3-phosphate (G-3-P) shuttle in the control of energy metabolism is well established. It is also known that its activity may be modulated by hormones involved in thermogenesis, such as thyroid hormones or dehydroepiandrosterone and its metabolites, that act by inducing de novo synthesis of mitochondrial G-3-P dehydrogenase (mGPDH). However, little is known as to the factors that may influence the activity without enzyme induction. In the present study we investigated the possible role of the G-3-P shuttle in the thermogenic response to different hypothermic stresses. It was found that a decrease of body temperature causes the liver rapidly to enhance mGPDH activity and G-3-P-dependent respiration. The enhancement, which does not result from de novo synthesis of enzymes, has the potential of increasing heat production both by decreased ATP synthesis during the oxidation of G-3-P and by activation of the glycolytic pathway.

The effect of 7-oxo-DHEA acetate on memory in young and old C57BL/6 mice

7-Oxo-dehydroepiandrosterone, which can be formed from dehydroepiandrosterone (DHEA) by several mammalian tissues, is more effective than its parent steroid as an inducer of thermogenic enzymes when administered to rats. Using the Morris water maze procedure, we tested DHEA and its 7-oxo-derivative for their ability to reverse the memory abolition induced by scopolamine in young C57BL/6 mice, and for their effect on memory in old mice. A single dose of 7-oxo-DHEA-acetate at 24 mg/kg b.w. completely reversed the impairment caused by 1 mg of scopolamine per kg b.w. (P < 0.001). DHEA (20 mg/kg) was also effective (P < 0.01). In old mice given the same single doses followed by feeding 0.05% of the respective steroid in the diet, memory of the water maze training was retained through a four week test period in mice receiving 7-oxo-DHEA-acetate (P < 0.05) but not in the control or DHEA-treated groups. When old mice were not tested until five weeks after being trained 7-oxo-DHEA exerted a slight, but statistically insignificant, improvement in memory retention. The possible effect of 7-oxo-DHEA in human memory problems deserves investigation.

Suppression of Delta(5)-androstenediol-induced androgen receptor transactivation by selective steroids in human prostate cancer cells

Our earlier report suggested that androst-5-ene-3beta,7beta-diol (Delta(5)-androstenediol or Adiol) is a natural hormone with androgenic activity and that two potent antiandrogens, hydroxyflutamide (Eulexin) and bicalutamide (Casodex), fail to block completely the Adiol-induced androgen receptor (AR) transactivation in prostate cancer cells. Here, we report the development of a reporter assay to screen several selective steroids with anti-Adiol activity. Among 22 derivatives/metabolites of dehydroepiandrosterone, we found 4 steroids [no. 4, 1,3,5(10)-estratriene-17alpha-ethynyl-3, 17beta-diol; no. 6, 17alpha-ethynyl-androstene-diol; no. 8, 3beta, 17beta-dihydroxy-androst-5-ene-16-one; and no. 10, 3beta-methylcarbonate-androst-5-ene-7,17-dione] that have no androgenic activity and could also block the Adiol-induced AR transactivation in prostate cancer PC-3 cells. Interestingly, these compounds, in combination with hydroxyflutamide, further suppressed the Adiol-induced AR transactivation. Reporter assays further showed that these four anti-Adiol steroids have relatively lower glucocorticoid, progesterone, and estrogenic activity. Together, these data suggest some selective steroids might have anti-Adiol activity, which may have potential clinical application in the battle against the androgen-dependent prostate cancer growth.

Development and validation of a high-performance liquid chromatography assay for the quantitative determination of 7-oxo-dehydroepiandrosterone-3beta-sulfate in human plasma

A new, simple, reproducible and reliable high-performance liquid chromatography method with ultraviolet absorbance detection at 240 nm was developed and validated for the determination of 7-oxo-dehydroepiandrosterone-3beta-sulfate in human plasma. The method was based upon solid-phase (C18) extraction of plasma after addition of 17beta-hydroxy-3beta-methoxyandrost-5-en-7-one as internal standard. Using 1 ml of plasma for extraction, the detection limit of the assay was 3 ng/ml. The standard curve was linear over the concentration range 10-1000 ng/ml. Stored at -20 degrees C for about 4 months at various concentrations in plasma, 7-oxo-dehydroepiandrosterone-3beta-sulfate did not reveal any appreciable degradation. Also included herein is a method for the simultaneous detection and determination of 7-oxo-dehydroepiandrosterone and 7-oxo-dehydroepiandrosterone-3beta-acetate in plasma.

An acute oral gavage study of 3beta-acetoxyandrost- 5-ene-7,17-dione (7-oxo-DHEA-acetate) in rats

The present study was done to assess the tolerance of rats for 3-acetoxyandrost-5-ene-7,17-dione (7-oxo-DHEA-acetate, 7-ODA) when administered as a single oral gavage dose. Five groups of Sprague-Dawley rats (Crl:CD (SD) BR VAF/Plus) (five/sex/group) were treated with 7-ODA at a dose level of 0 (control), 250, 500, 1000, or 2,000 mg/kg of body weight in a dose volume of 10 ml/kg. Food and water were provided ad libitum. All animals survived in good health to the scheduled sacrifice on Day 15. The single oral administration of 7-ODA had no apparent effects on body weight. Food consumption was significantly higher for all female treated groups during week two; however, the statistically significant differences were not considered to be of clinical consequence. Treatment caused no apparent changes of gross or microscopic anatomical structures of nine different organs. This study demonstrated that the no-observable adverse effect level for a single oral dose of 7-ODA in male and female rats was 2,000 mg/kg.

An escalating dose oral gavage study of 3beta-acetoxyandrost-5-ene-7, 17-dione (7-oxo-DHEA-acetate) in rhesus monkeys

To test the effects of 7-oxo-dehydroepiandrosterone-3 acetate (hereafter 7-ODA) in Rhesus macaques the steroid was administered by oral gavage to two male and two female monkeys. Dose levels of 250, 500, and 1,000 mg/kg body weight (BW)/day were administered on days 1, 3, and 5 respectively, and 1,000 mg/kg on days 7 through 11. Each group received the dose in a volume of 10 ml/kg BW. All animals survived to the scheduled sacrifice on day 12. No adverse clinical effects of 7-ODA were observed at the 250 or 500 mg/kg doses. Females vomited on non-treatment days and all animals vomited on some days after being given the 1000 mg/kg dose. Excessive salivation was observed before or immediately after dosing on days 9 through 11. Appearance, behavior and body weights were not altered by the treatments. Visual examination of all body cavities, and macroscopic and microscopic examination of 42 different organs and tissues found no lesions or abnormalities.

Ergosteroids III. Syntheses and biological activity of seco-steroids related to dehydroepiandrosterone

The unusual activity of some D-ring-seco estrogens led us to prepare several seco steroids related to dehydroepiandrosterone (DHEA) and to test for their ability to mimic thyroid hormone and 7-oxo-DHEA (1) as inducers of thermogenic enzymes in rats' livers. Only one, 3 beta-acetoxy-17a-oxa-androst-5-ene-7,17-dione (17), was capable of inducing both mitochondrial glycerophosphate dehydrogenase and malic enzyme. The closely related 3 beta-hydroxy-17a-oxa-androsta-5,15-diene-7,17-diones (both 14 alpha and 14 beta, 14 and 15) induce the formation of malic enzyme but not of glycerophosphate dehydrogenase. The 3 beta-propionyl ester of the above 14 alpha steroid was not active, presumably because it was not deacylated in vivo. The 16,17 dicarboxylic acid (9) produced by opening the D-ring also induced the formation of malic enzyme but not of glycerophosphate dehydrogenase. 3 beta-Acetoxyandrost-5-ene-7,16,17-trione, an intermediate in the synthesis of D-ring seco compounds enhanced the formation of both enzymes. Twelve other D-ring seco compounds were not active. Seco androstanes oxygenated at position 7 and with expanded A or B rings were not active.