Anti-proliferative action of endogenous dehydroepiandrosterone metabolites on human cancer cell lines

Novel Steroidal[17,16-d]pyrimidines Derived from Epiandrosterone and Androsterone: Synthesis, Characterization and Configuration-Activity Relationships

Two series of novel steroidal[17,16-d]pyrimidines derived from natural epiandrosterone and androsterone were designed and synthesized, and these compounds were screened for their potential anticancer activities. The preliminary bioassay indicated that some of these prepared compounds exhibited significantly good cytotoxic activities against human gastric cancer (SGC-7901), lung cancer (A549), and hepatocellular liver carcinoma (HepG2) cell lines compared with 5-fluorouracil (5-FU), epiandrosterone, and androsterone. Especially the respective pairs from epiandrosterone and androsterone showed significantly different inhibitory activities, and the possible configuration-activity relationships have also been summarized and discussed based on kinase assay and molecular docking, which indicated that the inhibition activities of these steroidal[17,16-d]pyrimidines might obviously be affected by the configuration of the hydroxyl group in the part of the steroidal scaffold.

Dehydroepiandrosterone in fibrotic interstitial lung disease: a translational study

BACKGROUND

Dehydroepiandrosterone (DHEA) is a precursor sex hormone with antifibrotic properties. The aims of this study were to investigate antifibrotic mechanisms of DHEA, and to determine the relationship between DHEA-sulfate (DHEAS) plasma levels, disease severity and survival in patients with fibrotic interstitial lung diseases (ILDs).

METHODS

Human precision cut lung slices (PCLS) and normal human lung fibroblasts were treated with DHEA and/or transforming growth factor (TGF)-β1 before analysis of pro-fibrotic genes and signal proteins. Cell proliferation, cytotoxicity, cell cycle and glucose-6-phosphate dehydrogenase (G6PD) activity were assessed. DHEAS plasma levels were correlated with pulmonary function, the composite physiologic index (CPI), and time to death or lung transplantation in a derivation cohort of 31 men with idiopathic pulmonary fibrosis (IPF) and in an independent validation cohort of 238 men and women with fibrotic ILDs.

RESULTS

DHEA decreased the expression of pro-fibrotic markers in-vitro and ex-vivo. There was no cytotoxic effect for the applied concentrations, but DHEA interfered in proliferation by modulating the cell cycle through reduction of G6PD activity. In men with IPF (derivation cohort) DHEAS plasma levels in the lowest quartile were associated with poor lung function and higher CPI (adjusted OR 1.15 [95% CI 1.03-1.38], p = 0.04), which was confirmed in the fibrotic ILD validation cohort (adjusted OR 1.03 [95% CI 1.00-1.06], p = 0.01). In both cohorts the risk of early mortality was higher in patients with low DHEAS levels, after accounting for potential confounding by age in men with IPF (HR 3.84, 95% CI 1.25-11.7, p = 0.02), and for age, sex, IPF diagnosis and prednisone treatment in men and women with fibrotic ILDs (HR 3.17, 95% CI 1.35-7.44, p = 0.008).

CONCLUSIONS

DHEA reduces lung fibrosis and cell proliferation by inducing cell cycle arrest and inhibition of G6PD activity. The association between low DHEAS levels and disease severity suggests a potential prognostic and therapeutic role of DHEAS in fibrotic ILD.

Investigation of Physiological Effects Induced by Dehydroepiandrosterone in Human Endothelial Cells and Ovarian Cancer Cell Line

Objectives

Dehydroepiandrosterone (DHEA) is an endogenous hormone that acts as a ligand for several cellular receptors. An age-dependent decline in circulating levels of DHEA is linked to changes in various physiological functions. In gynecological clinical practice, DHEA is commonly prescribed to induce ovulation. Some clinical studies report a positive association between high serum concentrations of DHEA and an increased risk of developing ovarian cancer. However, the in vitro physiological effects of DHEA on ovarian cancerous cells have not been explored thus far. In this study, we aimed to investigate the physiological effects of DHEA treatment (0-200 μM, 24-72 hours) on MDAH-2774 human ovarian cancer cell line and primary HuVeC human endothelial cells.

Materials and Methods

The physiological effects of DHEA treatment (0-200 μM, 24-72 hours) on MDAH-2774 human ovarian cancer cell line and primary HuVeC human endothelial cells were investigated with the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, acridine orange/ethidium bromide staining, and scratch assay.

Results

DHEA treatment promoted proliferation of the MDAH-2774 cancer cell line in a dose-dependent manner (r=0.6906, p<0.0001, for 24 hours) (r=0.6802, p<0.0001, for 48 hours) (r=0.7969, p<0.0001, for 72 hours). In contrast, DHEA inhibited proliferation of the primary HuVeC cells (r=0.9490, p<0.0001, for 24 hours) (r=0.9533, p<0.0001, for 48 hours) (r=0.9584, p<0.0001, for 72 hours). In agreement with these observations, DHEA treatment resulted in a dose-dependent increase in the number of necrotic cells in the primary HuVeC cells (r=0.97, p<0.0001). However, the number of necrotic or apoptotic cells did not change significantly when the MDAH-2774 cells was exposed to DHEA. Moreover, we found that DHEA treatment reduced the migration rate of HuVeC cells in a dose-dependent manner (r=0.9868, p<0.0001), whereas only a slight increase was observed in the MDAH-2774 ovarian cancer cell line (r=0.8938, p<0.05).

Conclusion

Our findings suggest that DHEA promotes the proliferation of ovarian cancer cells in a dose-dependent manner in vitro. Moreover, DHEA induced necrosis and inhibited proliferation in endothelial cells. Although mechanistic evidence is required, our preliminary findings imply that exposure to high doses of DHEA may be associated with an increased risk of developing ovarian cancer.

Microbial biotransformation of bioactive and clinically useful steroids and some salient features of steroids and biotransformation

Steroids are perhaps one of the most widely used group of drugs in present day. Beside the established utilization as immunosuppressive, anti-inflammatory, anti-rheumatic, progestational, diuretic, sedative, anabolic and contraceptive agents, recent applications of steroid compounds include the treatment of some forms of cancer, osteoporosis, HIV infections and treatment of declared AIDS. Steroids isolated are often available in minute amounts. So biotransformation of natural products provides a powerful means in solving supply problems in clinical trials and marketing of the drug for obtaining natural products in bulk amounts. If the structure is complex, it is often an impossible task to isolate enough of the natural products for clinical trials. The microbial biotransformation of steroids yielded several novel metabolites, exhibiting different activities. The metabolites produced from pregnenolone acetate by Cunning hamella elegans and Rhizopus stolonifer were screened against tyrosinase and cholinesterase showed significant inhibitory activities than the parent compound. Diosgenin and its transformed sarsasapogenin were screened for their acetyl cholinesterase and butyryl cholinesterase inhibitory activities. Sarsasapogenin was screened for phytotoxicity, and was found to be more active than the parent compound. Diosgenin, prednisone and their derivatives were screened for their anti-leishmanial activity. All derivatives were found to be more active than the parent compound. The biotransformation of steroids have been reviewed to a little extent. This review focuses on the biotransformation and functions of selected steroids, the classification, advantages and agents of enzymatic biotransformation and examines the potential role of new enzymatically transformed steroids and their derivatives in the chemoprevention and treatment of other diseases. tyrosinase and cholinesterase inhibitory activities, severe asthma, rheumatic disorders, renal disorders and diseases of inflammatory bowel, skin, gastrointestinal tract.

Dehydroepiandrosterone reduced lipid droplet accumulation via inhibiting cell proliferation and improving mitochondrial function in primary chicken hepatocytes

Dehydroepiandrosterone (DHEA) possesses fat-reducing effect, while little information is available on whether DHEA regulates cell proliferation and mitochondrial function, which would, in turn, affect lipid droplet accumulation in the broiler. In the present study, the lipid droplet accumulation, cell proliferation, cell cycle and mitochondrial membrane potential were analysis in primary chicken hepatocytes after DHEA treated. The results showed that total area and counts of lipid droplets were significantly decreased in hepatocytes treated with DHEA. The cell viability was significantly increased, while cell proliferation was significantly inhibited in a dose dependent manner in primary chicken hepatocytes after DHEA treated. DHEA treatment significantly increased the cell population in S phase and decreased the population in G2/M in primary chicken hepatocytes. Meanwhile, the cyclin A and cyclin-dependent kinases 2 (CDK2) mRNA abundance were significantly decreased in hepatocytes after DHEA treated. No significant differences were observed in the number of mitochondria, while the mitochondrial membrane permeability and succinate dehydrogenase (SDH) activity were significantly increased in hepatocytes after DHEA treated. In conclusion, our results demonstrated that DHEA reduced lipid droplet accumulation by inhibiting hepatocytes proliferation and enhancing mitochondrial function in primary chicken hepatocytes.

Autophagy and Autophagic Cell Death: Uncovering New Mechanisms Whereby Dehydroepiandrosterone Promotes Beneficial Effects on Human Health

Dehydroepiandrosterone (DHEA) is the most abundant steroid hormone in human serum and a precursor of sexual hormones. Its levels, which are maximum between the age of 20 and 30, dramatically decline with aging thus raising the question that many pathological conditions typical of the elderly might be associated with the decrement of circulating DHEA. Moreover, since its very early discovery, DHEA and its metabolites have been shown to be active in many pathophysiological contexts, including cardiovascular disease, brain disorders, and cancer. Indeed, treatment with DHEA has beneficial effects for the cure of these and many other pathologies in vitro, in vivo, and in patient studies. However, the molecular mechanisms underlying DHEA effects have been only partially elucidated. Autophagy is a self-digestive process, by which cell homeostasis is maintained, damaged organelles removed, and cell survival assured upon stress stimuli. However, high rate of autophagy is detrimental and leads to a form of programmed cell death known as autophagic cell death (ACD). In this chapter, we describe the process of autophagy and the morphological and biochemical features of ACD. Moreover, we analyze the beneficial effects of DHEA in several pathologies and the molecular mechanisms with particular emphasis on its regulation of cell death processes. Finally, we review data indicating DHEA and structurally related steroid hormones as modulators of both autophagy and ACD, a research field that opens new avenues in the therapeutic use of these compounds.

Amphiphilic derivatives of (3β,17β)-3-hydroxyandrost-5-ene-17-carboxylic acid

A series of amphiphilic derivatives of (3β,17β)-3-hydroxyandrost-5-ene-17-carboxylic acid (1) with the polyamine spermine and three other diamines, 1,2-diaminoethane, piperazine and cadaverine, were synthesized and their antimicrobial activity and cytotoxicity were investigated. Among the target compounds, several ones showed antimicrobial activity on Gram positive and Gram negative microorganisms. The most active compounds were 20 (Streptococcus mutans CCM 7409, 3.125 µM), 16 (Streptococcus mutans CCM 7409, 12.5 µM) and 10d (Escherichia coli CCM 3954, 12.5 µM). In addition, compounds 5d, 10d, 13 and 20 displayed cytotoxicity on CEM (12.1 ± 2.1 µM, 7.6 ± 1.0 µM, 19.0 ± 0.4 µM and 5.9 ± 0.7 µM, respectively). Two additional compounds displayed medium cytotoxicity on CEM, 5a (34.6 ± 5.2 µM) and 5c (37.7 ± 5.9 µM). The compound 13 and 20 displayed high toxicity also on normal fibroblasts.

The effect of newly synthesized progesterone derivatives on apoptotic and angiogenic pathway in MCF-7 breast cancer cells

Due to its high potency and selectivity, anticancer agents consisting of combined molecules have gained great interests. The current study introduces newly synthesized progesterone derivatives of promising anticancer effect. Moreover, the pro-apoptotic and anti-angiogenic effects of these compounds were studied extensively. Several thiazole, pyridine, pyrazole, thiazolopyridine and pyrazolopyridine progesterone derivatives were synthesized. The structure of the novel progesterone derivatives was elucidated and confirmed using the analytical and spectral data. This novel derivatives were tested for their cytotoxic effect against human breast cancer cells (MCF-7) using neutral red uptake assay. Tested compounds showed anticancer activity against MCF-7 cancer cell line in the descending order of 7>2>3>8>6>9>4. The expression levels of Bcl-2, survivin, CCND1, CDC2, P53 and P21, VEGF, Hif-1α, MMP-2, MMP-9, Ang-1, Ang-2, and FGF-1 genes were investigated using QRT-PCR (Quantitative real time-polymerase chain reaction). The study clarified that compounds 2, 3, 4, 6, 7, 8 and 9 showed significant pro-apoptotic effect through the down regulation of Bcl-2., besides, survivin and CCND1 expression levels were down regulated by compounds 3, 4, 6, 7, 8, 9. However, Compound 4 may exert this pro-apoptotic effect through the up-regulation of P53 gene expression. On the other hand, the anti-angiogenic effect of these newly synthesized derivatives was due to their down regulation of VEGF, Ang-2, MMP-9 and FGF-1; and the up-regulation of HIF-1α and ang-1. This study recommended promising pro-apoptotic and anti-angiogenic anticancer agents acting through the regulation of key regulators of apoptosis, cell cycle genes, and pro-angiogenic genes.

The Origin of 7α-Hydroxy-Dehydroepiandrosterone and Its Physiological Role: a History of Discoveries

Nearly 60 years has elapsed since the first isolation and identification of 7α-hydroxy-dehydroepiandrosterone, and in that time much information has been gained on its occurrence, metabolism, ontogeny, immunomodulatory activity, cell proliferation, cortisol control in local tissues and neuroactivity. Additional knowledge about this steroid may elucidate its role in obesity, neurodegenerative disturbances such as Alzheimer’s disease, or psychiatric disorders such as schizophrenia or depression. This review aims to provide a comprehensive summary of the available literature on 7α-hydroxy-dehydroepiandrosterone.

Evaluation of heterocyclic steroids and curcumin derivatives as anti-breast cancer agents: Studying the effect on apoptosis in MCF-7 breast cancer cells

Anticancer agents consisting of hybrid molecules are used to improve effectiveness and diminish drug resistance. The current study aimed to introduce newly synthesized hetero-steroids of promising anticancer effects. Besides, the pro-apoptotic effects of new compounds were investigated extensively. Several pyrimidino-, triazolopyrimidino-, pyridazino-, and curcumin-steroid derivatives were synthesized, elucidated and confirmed using the spectral and analytical data. The synthesized hetero-steroids, compounds 9, 10, 11, 12, 13, 14, 15, 18, 20, 21, 22 and 24, were tested for their cytotoxic effects versus human breast cancer cells (MCF-7) using neutral red supravital dye uptake assay. Compound 24 (IC50=18μM) showed more inhibitory influence on MCF-7 growth. Using QRT-PCR (Quantitative real time-polymerase chain reaction), CCND1, Survivin, BCL-2, CDC2, P21 and P53, genes expression levels were investigated. The study results disclose that compounds 4, 7, 18, 24 knocked down the expression levels of CCND1, Survivin, BCL-2 and CDC2. However, P21 and P53 were up-regulated by compounds 21, 22. This study introduced promising pro-apoptotic anticancer agents acting through the modulation of key regulators of apoptosis and cell cycle genes.

Effects of G6PD activity inhibition on the viability, ROS generation and mechanical properties of cervical cancer cells

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been revealed to be involved in the efficacy to anti-cancer therapy but the mechanism remains unclear. We aimed to investigate the anti-cancer mechanism of G6PD deficiency. In our study, dehydroepiandrosterone (DHEA) and shRNA technology were used for inhibiting the activity of G6PD of cervical cancer cells. Peak Force QNM Atomic Force Microscopy was used to assess the changes of topography and biomechanical properties of cells and detect the effects on living cells in a natural aqueous environment. Flow cytometry was used to detect the apoptosis and reactive oxygen species (ROS) generation. Scanning electron microscopy was used to observe cell morphology. Moreover, a laser scanning confocal microscope was used to observe the alterations in cytoskeleton to explore the involved mechanism. When G6PD was inhibited by DHEA or RNA interference, the abnormal Young's modulus and increased roughness of cell membrane were observed in HeLa cells, as well as the idioblasts. Simultaneously, G6PD deficiency resulted in decreased HeLa cells migration and proliferation ability but increased ROS generation inducing apoptosis. What's more, the inhibition of G6PD activity caused the disorganization of microfilaments and microtubules of cytoskeletons and cell shrinkage. Our results indicated the anti-cervix cancer mechanism of G6PD deficiency may be involved with the decreased cancer cells migration and proliferation ability as a result of abnormal reorganization of cell cytoskeleton and abnormal biomechanical properties caused by the increased ROS. Suppression of G6PD may be a promising strategy in developing novel therapeutic methods for cervical cancer.

The greedy nature of mutant RAS: a boon for drug discovery targeting cancer metabolism?

RAS oncogene mutations are frequently detected in human cancers. Among RAS-mediated tumorigenesis, KRAS-driven cancers are the most frequently diagnosed and resistant to current therapies. Despite more than three decades of intensive efforts, there are still no specific therapies for mutant RAS proteins. While trying to block those well-established downstream pathways, such as the RAF-MAPK pathway and the PI3K-AKT pathway, attentions have been paid to potential effects of RAS on metabolic pathways and the feasibility for targeting these pathways. Recent studies have proved that RAS not only promotes aerobic glycolysis and glutamine metabolism reprograming to provide energy, but it also facilitates branched metabolism pathways, autophagy, and macropinocytosis. These alterations generate building blocks for tumor growth and strengthen antioxidant defense in tumor cells. All of these metabolic changes meet different demands of RAS-driven cancers, making them distinct from normal cells. Indeed, some achievements have been made to inhibit tumor growth through targeting specific metabolism rewiring in preclinical models. Although there is still a long way to elucidate the landscape of altered metabolism, we believe that specific metabolic enzymes or pathways could be therapeutically targeted for selective inhibition of RAS-driven cancers.

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.

Synthesis of sex hormone-derived modified steroids possessing antiproliferative activity

During recent years intensive research has been focused on the synthesis of structurally modified steroid hormones in order to obtain compounds with beneficial biological activity such as cell-growth inhibition. Experimental results have revealed that some steroidal derivatives possess direct cytostatic effect on cancer cells in a hormone receptor-independent manner. After a brief account on the most important biological function and characteristics of the naturally occurring sex hormones in physiological and pathological conditions, structural modifications of estrane and androstane scaffolds are discussed in detail. The review covers literature publications (from 2002 to 2012) relating to the synthesis and antiproliferative activity of semisynthetic sex hormone-derived molecules containing simple or heterocyclic substituents. The compounds reviewed are divided into three main categories according to their sterane framework and the nature of substitution. This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors".

Metallocenes as Target Specific Drugs for Cancer Treatment

The application use of organometallic compounds into the cancer research was established in the late 1970s by Köpf-Maeir and Köpf. This new research area has been developed for the past thirty years. In the early 1980s, Jaouen and coworkers recognized the potential application of organometallic compounds vectorized with pendant groups that can deliver the drug to certain specific receptors. This is what is called nowdays Target Specific Drugs. This review will focus on metallocenes vectorized with steroids derivatives of hormones, nonsteroidal and selective endrocrine modulator.

Novel steroid inhibitors of glucose 6-phosphate dehydrogenase

Novel derivatives of the steroid DHEA 1, a known uncompetitive inhibitor of G6PD, were designed, synthesized, and tested for their ability to inhibit this dehydrogenase enzyme. Several compounds with approximately 10-fold improved potency in an enzyme assay were identified, and this improved activity translated to efficacy in a cellular assay. The SAR for steroid inhibition of G6PD has been substantially developed; the 3β-alcohol can be replaced with 3β-H-bond donors such as sulfamide, sulfonamide, urea, and carbamate. Improved potency was achieved by replacing the androstane nucleus with a pregnane nucleus, provided a ketone at C-20 is present. For pregnan-20-ones incorporation of a 21-hydroxyl group is often beneficial. The novel compounds generally have good physicochemical properties and satisfactory in vitro DMPK parameters. These derivatives may be useful for examining the role of G6PD inhibition in cells and will assist the future design of more potent steroid inhibitors with potential therapeutic utility.

Dehydroepiandrosterone reduces preadipocyte proliferation via androgen receptor

Several studies have suggested that both testosterone and dehydroepiandrosterone (DHEA) have weight-reducing and antidiabetic effects, especially in rodent studies; however, the precise mechanism of their action remains unclear. Here, we investigated the effect of DHEA on cell growth in adipose tissue. The appearance of senescence-associated β-galactosidase in stromal vascular fraction (SVF) isolated from Otsuka Long-Evans Tokushima fatty rats, an animal model of inherent obese type 2 diabetes, was prevented by DHEA administration. Next, the effects of DHEA and testosterone were compared in vivo and in vitro to evaluate whether these hormones influence cell growth in adipose tissue. Both DHEA and testosterone reduced body weight and epididymal fat weight equivalently when administered for 4 wk. To assess the effect of DHEA and testosterone on cell growth in adipose tissue, 5-bromo-2'-deoxyuridine (BrdU) uptake by SVF was measured. Quantification analysis of BrdU uptake by examining DNA isolated from each SVF revealed that treatment with DHEA and testosterone reduced cell replication. These results indicated that DHEA- and testosterone-induced decreased adiposity was associated with reduced SVF growth. Incubation with DHEA and testosterone equally decreased BrdU uptake by 3T3-L1 preadipocytes. Pretreatment with the androgen receptor (AR) inhibitor flutamide, but not the estrogen receptor inhibitor fulvestrant, abolished these effects. Knockdown of AR with siRNA also inhibited DHEA-induced decreases in BrdU uptake. These results suggest that DHEA-induced growth suppression of preadipocytes is mediated via AR. Therefore, both DHEA and testosterone similarly decrease adipocyte growth possibly via a common mechanism.

Oxidative metabolism of dehydroepiandrosterone (DHEA) and biologically active oxygenated metabolites of DHEA and epiandrosterone (EpiA)--recent reports

Dehydroepiandrosterone (DHEA) is a multifunctional steroid with a broad range of biological effects in humans and animals. DHEA can be converted to multiple oxygenated metabolites in the brain and peripheral tissues. The mechanisms by which DHEA exerts its effects are not well understood. However, evidence that the effects of DHEA are mediated by its oxygenated metabolites has accumulated. This paper will review the panel of oxygenated DHEA metabolites (7, 16 and 17-hydroxylated derivatives) including a number of 5α-androstane derivatives, such as epiandrosterone (EpiA) metabolites. The most important aspects of the oxidative metabolism of DHEA in the liver, intestine and brain are described. Then, this article reviews the reported biological effects of oxygenated DHEA metabolites from recent findings with a specific focus on cancer, inflammatory and immune processes, osteoporosis, thermogenesis, adipogenesis, the cardiovascular system, the brain and the estrogen and androgen receptors.

Bioactivities and antiradical properties of millet grains and hulls

Antioxidant activities of phenolic extracts of kodo and pearl millet whole grains, dehulled grains, and hulls were examined by monitoring inhibition of radical-induced DNA scission, human low-density lipoprotein (LDL) cholesterol, and phospholipid liposome oxidation. Total phenolic content (TPC), hydroxyl and peroxyl radical inhibition, and antiproliferative activities against HT-29 cells were also determined. Major hydroxycinnamic acids in dehulled grains and hulls were identified and quantified using HPLC. Phenolic extract of kodo millet exhibited higher inhibition activities against oxidation of LDL cholesterol and liposome than that of pearl millet. All phenolic extracts exhibited a dose-dependent inhibition of DNA scission. The TPC of hulls of kodo and pearl millets were 3 times higher than those of their corresponding whole grains. At the end of 96 h of incubation, kodo millet extracts inhibited cell proliferation in the range of 75-100%. Antioxidant activities of phenolic extracts were in the order hull > whole grain > dehulled grain. Dehulling reduced the antioxidant potential of whole millet grains. Ferulic and p-coumaric acids were the major hydroxycinnamic acids, and their contents ranged from 17.8 to 1685 μg/g defatted meal and from 3.5 to 680 μg/g defatted meal, respectively. Dehulled grains, as well as the hull fraction, may serve as potential sources of nutraceutical and functional food ingredients in health promotion.

Biochemical disorders associated with antiproliferative effect of dehydroepiandrosterone in hepatoma cells as revealed by LC-based metabolomics

DHEA is known to have chemopreventive and antiproliferative activities, and was initially thought to be mediated by inhibition of G6PD. Our previous study has shown that DHEA may act through interference with energy metabolism. To study the effect of pharmacological dose of DHEA on cellular metabolism, and to further delineate the mechanism underlying its antiproliferative effect, we applied a metabolomic approach to globally profile the changes in metabolites in SK-Hep1 cells underexpressing G6PD (Sk-Gi) and control cells (Sk-Sc) after DHEA treatment. RRLC-TOF-MS was used to identify metabolites, and tandem mass spectrometry was used to confirm their identity. DHEA induced changes in glutathione metabolism, lipid metabolism, s-adenosylmethionine (SAM) metabolism, as well as lysine metabolism. Elevation in level of glutathione disulfide, together with a concomitant decrease in level of reduced glutathione, was indicative of increased oxidative stress. Depletion of carnitine and its acyl derivatives reflected decline in fatty acid catabolism. These changes were associated with mitochondrial malfunction and reduction in cellular ATP content. Cardiolipin (CL) and phosphatidylcholine (PC) levels decreased significantly, suggesting that alterations in lipid composition are causally related to decline in mitochondrial function after DHEA treatment. The decline in cellular SAM content was accompanied by decreased expression of methionine adenosyltransferase genes MAT2A and MAT2B. SAM supplementation partially rescued cells from DHEA-induced growth stagnation. Our findings suggest that DHEA causes perturbation of multiple pathways in cellular metabolism. Decreased SAM production, and cardiolipin depletion and the resulting mitochondrial dysfunction underlie the antiproliferative effect of DHEA.

Effects of dehydroepiandrosterone on proliferation, migration, and death of breast cancer cells

Cancer invasion and metastasis are the leading causes of mortality in patients with breast cancer. Dehydroepiandrosterone (DHEA) has a protective role against cancer, however, the mechanism by which DHEA has this effect remains poorly understood. The present study was aimed at investigating the actions of DHEA on the proliferation, cell cycle, death and migration of breast cancer cell lines. We used MCF-7 cells (estrogen receptors positive) and MDA-MB-231 and Hs578T cells (estrogen receptors negative) for these studies. Cell proliferation was evaluated by crystal violet staining, cell cycle by flow cytometry, and cell death by the carboxyfluorescein FLICA analysis of caspase activation. Migration was evaluated by transwell cell migration and wound assay. We also determined the expression of ECM-1 protein by western blotting and RT-PCR in real time. DHEA inhibited the proliferation of all breast cancer cell lines. This was associated with an arrest in the G1 phase of the cell cycle and death in MCF-7 cells. There was no alteration in any of the cell cycle phases or death in DHEA treated MDA-MB-231 or Hs578T cells. DHEA also suppressed the migration of all breast cancer cell lines, independently of the presence of estrogen receptors and decreased the expression of ECM-1 protein in Hs578T cells. These results suggest that the mechanism of DHEA actions against breast cancer involves the inhibition of cell proliferation and the suppression of migration, indicating that DHEA could be useful in the treatment of breast cancer.

New insights into the protective effects of DHEA1)

Numerous studies investigated the effects of pharmacological doses of DHEA in animals. Among protective effects, antiglucocorticoid potencies, triggering and modulation of immunity and anticancerous effects were reported. Because DHEA levels decrease in aging humans, this steroid has been assayed as replacement therapy in elderly volunteers without striking evidence for beneficial effects. Examination of the investigations carried out in animals lead to suspect that, rather than DHEA, its metabolites produced in tissues could be responsible for some of the observed effects. Known as the "mother steroid", DHEA is a precursor for androgenic and estrogenic steroid hormones. In addition, DHEA is hydroxylated at the 7α position by the cytochrome P450 7B1 (CYP7B1), and the 7α-hydroxy-DHEA produced is a substrate for the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which converts it into 7β-hydroxy-DHEA. Both 7-hydroxylated metabolites were shown to favor the onset of immunity in mice and the activation of memory T cells in humans. Other DHEA and testosterone-derived metabolites, namely epiandrosterone and 5α-androstane-3β,17β-diol, are also substrates for the CYP7B1 and their 7α-hydroxylated products were also converted into the 7β epimer by the 11β-HSD1. When assayed at doses 104 lower than DHEA, 7β-hydroxy-epiandrosterone was shown to shift the prostaglandin metabolism patterns from prostaglandin E2 (PGE2) to PGD2 production, thus triggering the resolution of inflammation. In addition, 7β-hydroxy-epiandrosterone (1 nM) exerted the same effects as tamoxifen (1 μM) on the proliferation of MCF-7 and MDA-231 human breast cancer cells. These findings suggest that the observed effects of 7β-hydroxy-epiandrosterone could be mediated by estrogen receptors. This overview of recent research implies that DHEA does not act directly and that its effects are due to its metabolites when produced in tissues. Treatments with DHEA should take into account the target tissue abilities to produce the desired metabolites through the two key enzymes, CYP7B1 and 11β-HSD1.

Synthesis and cytotoxicity studies of steroid-functionalized titanocenes as potential anticancer drugs: sex steroids as potential vectors for titanocenes

Six titanocenyls functionalized with steroidal esters have been synthesized and characterized by infrared, (1)H, and (13)C NMR spectroscopy and elemental analysis. Among those steroids, dehydroepiandrosterone, trans-androsterone, and androsterone are androgens and pregnenolone is a progesterone precursor. Clionasterol is a natural steroid compound. These steroid-functionalized titanocenyls were tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for in vitro cytotoxicity for MCF-7 breast cancer and HT-29 colon cancer cells. All complexes exhibited more cytotoxicity than titanocene dichloride. The titanocenyls containing androgen and progesterone derivatives as pendant groups had higher antiproliferative activities than those with cholesterol steroid compounds. Of particular significance is titanocenyl-dehydroepiandrosterone complex, which is 2 orders of magnitude more cytotoxic than titanocene dichloride and also shows much more sensitivity and selectivity for the MCF-7 cell line.

Dehydroepiandrosterone reverses systemic vascular remodeling through the inhibition of the Akt/GSK3-{beta}/NFAT axis

BACKGROUND

The remodeled vessel wall in many vascular diseases such as restenosis after injury is characterized by proliferative and apoptosis-resistant vascular smooth muscle cells. There is evidence that proproliferative and antiapoptotic states are characterized by a metabolic (glycolytic phenotype and hyperpolarized mitochondria) and electric (downregulation and inhibition of plasmalemmal K(+) channels) remodeling that involves activation of the Akt pathway. Dehydroepiandrosterone (DHEA) is a naturally occurring and clinically used steroid known to inhibit the Akt axis in cancer. We hypothesized that DHEA will prevent and reverse the remodeling that follows vascular injury.

METHODS AND RESULTS

We used cultured human carotid vascular smooth muscle cell and saphenous vein grafts in tissue culture, stimulated by platelet-derived growth factor to induce proliferation in vitro and the rat carotid injury model in vivo. DHEA decreased proliferation and increased vascular smooth muscle cell apoptosis in vitro and in vivo, reducing vascular remodeling while sparing healthy tissues after oral intake. Using pharmacological (agonists and antagonists of Akt and its downstream target glycogen-synthase-kinase-3beta [GSK-3beta]) and molecular (forced expression of constitutively active Akt1) approaches, we showed that the effects of DHEA were mediated by inhibition of Akt and subsequent activation of GSK-3beta, leading to mitochondrial depolarization, increased reactive oxygen species, activation of redox-sensitive plasmalemmal voltage-gated K(+) channels, and decreased [Ca(2+)](i). These functional changes were accompanied by sustained molecular effects toward the same direction; by decreasing [Ca(2+)](i) and inhibiting GSK-3beta, DHEA inhibited the nuclear factor of activated T cells transcription factor, thus increasing expression of Kv channels (Kv1.5) and contributing to sustained mitochondrial depolarization. These results were independent of any steroid-related effects because they were not altered by androgen and estrogen inhibitors but involved a membrane G protein-coupled receptor.

CONCLUSIONS

We suggest that the orally available DHEA might be an attractive candidate for the treatment of systemic vascular remodeling, including restenosis, and we propose a novel mechanism of action for this important hormone and drug.

Inhibition of Trypanosoma brucei glucose-6-phosphate dehydrogenase by human steroids and their effects on the viability of cultured parasites

Dehydroepiandrosterone (DHEA) is known as an intermediate in the synthesis of mammalian steroids and a potent uncompetitive inhibitor of mammalian glucose-6-phosphate dehydrogenase (G6PDH), but not the enzyme from plants and lower eukaryotes. G6PDH catalyzes the first step of the pentose-phosphate pathway supplying cells with ribose 5-phosphate, a precursor of nucleic acid synthesis, and NADPH for biosynthetic processes and protection against oxidative stress. In this paper we demonstrate that also G6PDH of the protozoan parasite Trypanosoma brucei is uncompetitively inhibited by DHEA and epiandrosterone (EA), with K(i) values in the lower micromolar range. A viability assay confirmed the toxic effect of both steroids on cultured T. brucei bloodstream form cells. Additionally, RNAi mediated reduction of the G6PDH level in T. brucei bloodstream forms validated this enzyme as a drug target against Human African Trypanosomiasis. Together these findings show that inhibition of G6PDH by DHEA derivatives may lead to the development of a new class of anti-trypanosomatid compounds.

Dehydroepiandrosterone, epiandrosterone and synthetic derivatives inhibit Junin virus replication in vitro

In the present paper the in vitro antiviral activity of dehydroepiandrosterone (DHEA), epiandrosterone (EA) and 16 synthetic derivatives against Junin virus (JUNV) replication in Vero cells was studied. DHEA and EA caused a selective inhibition of the replication of JUNV and other members of the Arenaviridae family such as Pichinde virus and Tacaribe virus. The compounds were not virucidal to cell-free JUNV. The impairment of viral replication was not due to an inhibitory effect of the steroids on virus adsorption or internalization. An inhibitory effect of the compounds on JUNV protein synthesis and both intracellular and extracellular virus production was demonstrated. A partial inhibitory action on cell surface expression of JUNV glycoprotein G1 was also detected on DHEA- and EA-treated cultures. Like DHEA and EA, three compounds obtained from EA by chemical synthesis showed selectivity indexes higher than ribavirin, the only antiviral compound that has shown partial efficacy against arenavirus infections.

Enhancing antioxidant, antiproliferation, and free radical scavenging activities in strawberries with essential oils

Several natural antimicrobial compounds derived from essential oils of plants were investigated for their efficacies in inhibiting decay and extending the shelf life of strawberries (Fragaria x ananassas Duch.). The severity of decay in strawberries stored at 10 degrees C was significantly reduced by treatment with thymol. Treatments with menthol or eugenol also suppressed the fungal growth, but to a lesser extent. All of these three natural antimicrobial compounds extended shelf life of strawberries as compared to the control. Strawberries treated with thymol, menthol, or eugenol also maintained better fruit quality with higher levels of sugars, organic acids, phenolics, anthocyanins, flavonoids, and oxygen radical absorbance capacity than the untreated fruits. The free radical scavenging properties of strawberry fruit were evaluated against 2,2-diphenyl-1-picryhydrazyl (DPPH(.)), hydroxyl (HO(.)), and superoxide radicals (O2(.-)) using electron spin resonance measurements. Higher radical scavenging capacities were found against DPPH(.) and HO(.) in all treated fruit, particularly in berries treated with thymol, compared to those in the control groups. In addition, strawberry extracts were evaluated for their antiproliferative activities using HT-29 colon cancer cells. Extracts from all treated fruit exhibited significantly stronger inhibition on HT-29 cell proliferation than those from the control fruit. These data provide evidence that, in addition to possessing antimicrobial activity, the essential oils also increase free radical scavenging capacity and antiproliferative activity in fruit and, in turn, enhance the resistance of fruit tissues to deterioration and spoilage.

The neuro-steroid, 3beta androstene 17alpha diol exhibits potent cytotoxic effects on human malignant glioma and lymphoma cells through different programmed cell death pathways

The neuro-steroids 3β-androstene-17α-diol (17α-AED), 3β-androstene-17β-diol (17β-AED), 3β-androstene-7α,-17β-triol (7α-AET) and 3β-androstene-7β,-17β-triol (7β-AET) are metabolites of dehydroepiandrosterone and are produced in neuro-ectodermal tissue. Both epimers of androstenediols (17α-AED and 17β-AED) and androstenetriols (7α-AET and 7β-AET) have markedly different biological functions of their chemical analogue. We investigated the cytotoxic activity of these neuro-steroids on human T98G and U251MG glioblastoma and U937 lymphoma cells. Proliferation studies showed that 17α-AED is the most potent inhibitor, with an IC₅₀ ∼15 μM. For T98G glioma, 90% inhibition was achieved with 25 μM of 17α-AED. Other neuro-steroids tested only marginally suppressed cell proliferation. Reduced cell adherence and viability could be detected after 18 h of 17α-AED exposure. Treatment with 17α-AED induced a significant level of apoptosis in U937 lymphoma cells, but not in the glioma cells. Cytopathology of 17α-AED-treated T98G cells revealed the presence of multiple cytoplasmic vacuoles. Acridine orange staining demonstrated the formation of acidic vesicular organelles in 17α-AED-treated T98G and U251MG, which was inhibited by bafilomycin A1. These findings indicate that 17α-AED bears the most potent cytotoxic activity of the neuro-steroids tested, and the effectiveness may depend on the number of hydroxyls and their position on the androstene molecule. These cytotoxic effects may utilize a non-apoptotic pathway in malignant glioma cells.

Antioxidative and antiproliferative properties of selected barley (Hordeum vulgarae L.) cultivars and their potential for inhibition of low-density lipoprotein (LDL) cholesterol oxidation

Aqueous methanolic extracts of whole kernels from six different barley cultivars, namely, Falcon, AC Metcalfe, Tyto, Tercel, Phoenix, and Peregrine, were examined for their total phenolic content (TPC), oxygen radical scavenging capacity (ORACFL), hydroxyl radical scavenging capacity (HORACFL), potency in prevention of lipid oxidation using the Rancimat method, efficacy in inhibition of Cu(II)-induced human LDL cholesterol oxidation, and antiproliferative activities using Caco-2 colorectal adenocarcinoma cell line. Total phenolic content as measured by Folin-Ciocalteu's method ranged from 0.68 to 1.19 mg of ferulic acid equiv/g of defatted material, whereas ORACFL and HORACFL values were 11.28-19.10 and 9.06-12.99 micromol of Trolox equiv/g of defatted material, respectively. Protection factor (PF), a measure of the effect of extracts on the prevention of oxidation of stripped corn oil as measured by Rancimat, ranged from 0.97 to 1.59. Furthermore, barley extracts showed 19.64-33.93% inhibition against Cu(II)-induced human LDL cholesterol oxidation at a final concentration of 0.02 mg/mL. The proliferation of Caco-2 colon cancer cells was significantly (p < 0.05) inhibited in a dose-dependent fashion in the presence of all barley extracts tested at the end of the day 4 of incubation. At the end of day 4, barley extracts rendered 29.3-51.2 and 9.3-15.9% inhibition of cell proliferation at 0.5 and 0.05 mg/mL, respectively. Phenolic extracts from whole barley kernel tested possessed high antioxidant, antiradical, and antiproliferative potentials. Therefore, inclusion of whole barley into the daily diet may render beneficial health benefits.

The native anti-glucocorticoid paradigm

Circulating 3beta-hydroxysteroids including dehydroepiandrosterone (DHEA) are 7alpha-hydroxylated by the cytochrome P450-7B1 in the liver, skin and brain, which are the target organs of glucocorticoids. Anti-glucocorticoid effects with 7alpha-hydroxy-DHEA were observed in vivo without an interference with glucocorticoid binding to its receptor. In the organs mentioned above, the circulating inactive cortisone was reduced into active cortisol by the 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). We demonstrated that 7alpha-hydroxy-DHEA was also a substrate for this enzyme. Studies of the 11beta-HSD1 action on 7alpha-hydroxy-DHEA showed the reversible production of 7beta-hydroxy-DHEA through an intermediary 7-oxo-DHEA, and the kinetic parameters favored this production over that of active glucocorticoids. Both the production of 7alpha-hydroxysteroids and their interference with the activation of cortisone into cortisol are basic to the concept of native anti-glucocorticoids efficient at their production site. This opens a promising new area for research.

Chemical compositions, antioxidant capacities, and antiproliferative activities of selected fruit seed flours

Seed flours from black raspberry, red raspberry, blueberry, cranberry, pinot noir grape, and chardonnay grape were examined for their total fat content, fatty acid composition, total phenolic content (TPC), total anthocyanin content (TAC), radical scavenging capacities against the peroxyl (ORAC) and stable DPPH radicals, chelating capacity against Fe(2+), and antiproliferative activities using the HT-29 colon cancer cell line. Significant levels of fat were detected in the fruit seed flours and their fatty acid profiles may differ from those of the respective seed oils. Cranberry seed flour had the highest level of alpha-linolenic acid (30.9 g/100 g fat) and the lowest ratio of n-6/n-3 fatty acids (1.2/1). The ORAC value of the chardonnay seed flour was 1076.4 Trolox equivalents mumol/g flour, and its TPC was 186.3 mg gallic acid equivalents/g flour. These values were 3-12 times higher than the other tested fruit seed flours. Furthermore, the ORAC value was significantly correlated to the TPC under the experimental conditions (P < 0.05). These fruit seed flours also differed in their TAC values and Fe(2+)-chelating capacities. In addition, black raspberry, cranberry, and chardonnay grape seed flour extracts were evaluated for their antiproliferative effects using HT-29 colon cancer cells. All three tested seed flour extracts significant inhibited HT-29 cell proliferation. The data from this study suggest the potential of developing the value-added use of these fruit seed flours as dietary sources of natural antioxidants and antiproliferative agents for optimal human health.

Dehydroepiandrosterone decreases while cortisol increases in vitro growth and viability of Entamoeba histolytica

In vitro exposure of Entamoeba histolytica trophozoites to the sex steroids 17beta-estradiol, progesterone, and dehydrotestosterone had little effect on parasite viability or proliferation. However, treatment with the adrenal steroid dehydroepiandrosterone (DHEA) markedly inhibited parasite proliferation, adherence and motility, and at a certain dose it induced trophozoite lysis. The opposite effect on proliferation was found when the trophozoites were exposed to cortisol. Moreover, DHEA decreased while cortisol increased the parasite's DNA synthesis determined by 3H-thymidine incorporation. Trophozoite lysis by DHEA appeared to be caused by a necrotic rather than an apoptotic process, as observed in propidium iodide and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling assays. A possible mechanisms of action was derived from experiments demonstrating that the activity of a putative 3-hydroxy-3-methyl glutaryl CoA reductase detected in trophozoite extracts was inhibited in the presence of DHEA. Contrary to its in vitro inhibitory effect, in vivo administration of DHEA to infected hamsters resulted in exacerbation of the amebic liver abscesses. These results demonstrated that androgen steroids act directly upon E. histolytica growth and viability, and may shed new light on some age and gender differences in disease progression, as well as finding application in the drug treatment of human amebiasis.

Dehydroepiandrosterone inhibits the proliferation of human umbilical vein endothelial cells by enhancing the expression of p53 and p21, restricting the phosphorylation of retinoblastoma protein, and is androgen- and estrogen-receptor independent

Dehydroepiandrosterone (DHEA), a steroid hormone, modified the proliferation of human umbilical vein endothelial cells in a dose-dependent manner. Its inactive sulfate ester (DHEA-S) and two of its metabolites -- estradiol and testosterone -- had no inhibitory effect at physiological concentrations. Antiproliferation was associated with arrest in the G1 phase of the cell cycle, but not with cell death, as evaluated by cleavage of poly(ADP-ribose) polymerase and exposure of phosphatidylserine. The effect was not blocked by inhibitors of androgen or estrogen receptors. DHEA diminished the levels of phosphorylated retinoblastoma protein and increased the expression of p53 and p21 mRNAs. These results show that DHEA inhibits endothelial cell proliferation by regulating cell cycle relevant proteins through a cytoplasmic steroid hormone-independent pathway.

All-trans Retinoic Acid Induction of Sulfotransferases

All-trans retinoic acid is the bioactive form of vitamin A (retinol). Retinoids have been used clinically as therapeutic agents against a number of cancers. Retinoids have been reported to induce the phase I drug metabolizing enzymes, cytochrome P-450s. In contrast, effects of retinoids on sulfotransferases have not been as well studied. The present investigation evaluates the role of retinoic acid on the expression of aryl sulfotransferase IV and hydroxysteroid sulfotransferase a in male and female Sprague-Dawley rat liver and intestine. Cultured human hepatic carcinoma cells (Hep G2) and intestinal carcinoma cells (Caco-2) were also used to study retinoic acid's effect on simple phenol sulfating sulfotransferase, dehydroepiandrosterone sulfotransferase and oestrogen sulfotransferase. Enzyme assay and Western blot were used to determine sulfotransferase protein expression. Retinoic acid induced aryl sulfotransferase IV in liver of female rats and sulfotransferase a in liver of male rats. Intestinal rat aryl sulfotransferase IV and sulfotransferase a in male rats and intestinal aryl sulfotransferase IV in female rats were also induced after retinoic acid treatment. In Hep G2 and Caco-2 cells, retinoic acid differentially induced the three human sulfotransferase isoforms. In general, intestinal sulfotransferases were found to be more responsive than hepatic sulfotransferases to retinoic acid treatment. mRNA expressions were investigated using reverse transcription polymerase chain reaction with gene specific primers. Reverse transcription polymerase chain reaction results are in good agreement with enzyme activity and Western blot results. This suggests that retinoic acid induction of sulfotransferases is at the transcriptional level.

Simultaneous determination of dehydroepiandrosterone and its 7-oxygenated metabolites in human serum by high-resolution gas chromatography--mass spectrometry

A highly sensitive and specific method has been developed for the simultaneous measurement of free (unconjugated) or sulfate-conjugated forms of dehydroepiandrosterone (DHEA), 7alpha-hydroxy-DHEA (7alpha-OH-DHEA), 7beta-hydroxy-DHEA (7beta-OH-DHEA), and 7-oxo-DHEA (7-oxo-DHEA) in human serum. This method is based upon a stable isotope-dilution technique by gas chromatography-selected-ion monitoring mass spectrometry. Free steroids were extracted from serum with an organic solvent and the sulfate-conjugated steroids remained in aqueous phase. Free steroids were purified by solid-phase extraction, while sulfate-conjugated steroids were hydrolyzed by sulfatase and deconjugated steroids were purified by solid-phase extractions. The extracts were treated with O-methylhydroxylamine hydrochloride and were subsequently dimethylisopropylsilylated. The resulting methyloxime-dimethylisopropylsilyl (MO-DMIPS) ether derivatives were quantified by gas chromatography-selected-ion monitoring mass spectrometry in a high-resolution mode. The detection limits of MO-DMIPS ether derivatives of DHEA, 7alpha-OH-DHEA, 7beta-OH-DHEA and 7-oxo-DHEA were 1.0, 0.5, 0.5 and 2.0pg, respectively. Coefficients of variation between samples ranged from 10.6 to 22.9% for free 7-oxygenated DHEA to less than 10% for DHEA and sulfate-conjugated 7-oxygenated DHEA. The concentrations of these steroids were measured in 18 sera samples from healthy volunteers (9 males and 9 females; aged 23-78 years). Free DHEA, 7alpha-OH-DHEA, 7beta-OH-DHEA and 7-oxo-DHEA levels ranged between 0.21-3.55, 0.001-0.194, 0.003-0.481, and 0.000-0.077ng/ml, respectively, and the sulfate-conjugated steroid levels of these metabolites ranged between 253-4681, 0.082-3.001, 0.008-0.903, and 0.107-0.803ng/ml, respectively. The free DHEA-related steroid concentrations were much lower than those previously measured by RIA and low-resolution GC-MS. The present method made it possible to determine simultaneously serum DHEA-related steroid levels with sufficient sensitivity and accuracy.

Dehydroepiandrosterone sulphate (DHEAS) inhibits growth of human vascular endothelial cells

Dehydroepiandrosterone sulphate (DHEAS) is a steroid product of the adrenal gland, which circulates in high concentrations, but whose functions are largely unknown. There is evidence for antiproliferative effects of DHEAS in neoplastic tissue. The present study was designed to investigate the effects of DHEAS on vascular endothelial cell proliferation. It was found that DHEAS at physiological concentrations (10 microM) caused inhibition of cellular growth, which was reversible following removal of the steroid. This effect was not mimicked by other steroids, suggesting that it is not mediated by androgen or estrogen receptors. Uptake of 3H-thymidine was not altered by DHEAS, suggesting that this steroid may induce apoptosis in vascular endothelial cells.

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.

Dehydroepiandrosterone, a sex steroid metabolite in development for systemic lupus erythematosus

Deficiency of the weak androgen dehydroepiandrosterone (DHEA) and its sulfoconjugated metabolite DHEA-S has been associated with a number of serious illnesses, including lupus, diabetes, Alzheimer's disease and some cancers. Accordingly, supplementation with DHEA has been proposed for a variety of illnesses. Observational clinical studies and in vitro experiments have suggested that DHEA treatment might have a significant impact on immunological function, bone density, cognition, atherosclerotic disease, some malignancies, insulin resistance and obesity. Endogenous circulating DHEA levels, however, may vary widely by gender, age and ethnicity and can be affected by acute changes in corticosteroid production, alcohol intake, smoking, body mass index, medications and thyroid function [1-3]. Clearly, these variables complicate the interpretation of clinical data. DHEA also gives rise to a number of as yet poorly characterised metabolites, further confusing the assessment of its net effects when considered as treatment in heterogenous populations. Given the complexity of potential effects of DHEA and its metabolites, coupled to the diversity of clinical conditions that they might, at least in theory, affect, it is not surprising that clinical confirmation of efficacy in several clinical contexts has been inconsistent and controversial, hampering drug development in what might potentially be an important and widespread market. The current review will consider recent work suggesting efficacy of DHEA (GL-701, prasterone, Prestara( trade mark ) [US], Anastar( trade mark ) [Europe]; Genelabs) in systemic lupus erythematosus.