Advances in the analytical methodologies: Profiling steroids in familiar pathways-challenging dogmas.

The comprehensive evaluation of the adrenal steroidogenic pathway, given its complexity, requires methodology beyond the standard techniques currently employed. Advances in LC-MS/MS, coupled with in vitro cell models that produce all the steroid metabolites of the mineralo-, glucocorticoid and androgen arms, present a powerful approach for the comprehensive evaluation of adrenal steroidogenesis in response to compounds of interest including bioactives, drug treatments and endocrine disrupting compounds. UHPLC-MS/MS analysis of steroid panels in forskolin, angiotensin II and K(+) stimulated H295R cells provides a snapshot of their effect on intermediates and end products of adrenal steroidogenesis. The impact of full steroid panel evaluations by LC- and GC-MS/MS extends to clinical profiling with the characterization of normal pediatric steroid reference ranges in sexual development and of disease-specific profiles improving diagnosis and sub classification. Comprehensive analyses of steroid profiles may potentially improve patient outcomes together with the application of treatments specifically suited to clinical subgroups. LC-MS/MS and GC-MS/MS applications in the analyses of comprehensive steroid panels are demonstrated in clinical conditions such as congenital adrenal hyperplasia in newborns requiring accurate diagnoses and in predicting metabolic risk in polycystic ovary syndrome patients. Most notable perhaps is the impact of LC-MS/MS evaluations on our understanding of the basic biochemistry of steroidogenesis with the detection of the long forgotten adrenal steroid, 11ß-hydroxyandrostenedione, at significant levels. The characterization of its metabolism to androgen receptor ligands in the LNCaP prostate cancel cell model, specifically within the context of recurring prostate cancer, lends new perspectives to old dogmas. We demonstrate that UHPLC-MS/MS has enabled the analyses of novel metabolites of the enzymes, SRD5A, 11ßHSD and 17ßHSD, in LNCaP cells. Undoubtedly, the continuous advances in the analytical methodologies used for steroid profiling and quantification will give impetus to the unraveling of the remaining enigmas, old and new, of both hormone biosynthesis and metabolism.

Rooibos flavonoids inhibit the activity of key adrenal steroidogenic enzymes, modulating steroid hormone levels in H295R cells.

Major rooibos flavonoids--dihydrochalcones, aspalathin and nothofagin, flavones--orientin and vitexin, and a flavonol, rutin, were investigated to determine their influence on the activity of adrenal steroidogenic enzymes, 3ß-hydroxysteroid dehydrogenase (3ßHSD2) and cytochrome P450 (P450) enzymes, P450 17α-hydroxylase/17,20-lyase (CYP17A1), P450 21-hydroxylase (CYP21A2) and P450 11ß-hydroxylase (CYP11B1). All the flavonoids inhibited 3ßHSD2 and CYP17A1 significantly, while the inhibition of downstream enzymes, CYP21A2 and CYP11B1, was both substrate and flavonoid specific. The dihydrochalcones inhibited the activity of CYP21A2, but not that of CYP11B1. Although rutin, orientin and vitexin inhibited deoxycortisol conversion by CYP11B1 significantly, inhibition of deoxycorticosterone was <20%. These three flavonoids were unable to inhibit CYP21A2, with negligible inhibition of deoxycortisol biosynthesis only. Rooibos inhibited substrate conversion by CYP17A1 and CYP21A2, while the inhibition of other enzyme activities was <20%. In H295R cells, rutin had the greatest inhibitory effect on steroid production upon forskolin stimulation, reducing total steroid output 2.3-fold, while no effect was detected under basal conditions. Nothofagin and vitexin had a greater inhibitory effect on overall steroid production compared to aspalathin and orientin, respectively. The latter compounds contain two hydroxyl groups on the B ring, while nothofagin and vitexin contain a single hydroxyl group. In addition, all of the flavonoids are glycosylated, albeit at different positions--dihydrochalcones at C3' and flavones at C8 on ring A, while rutin, a larger molecule, has a rutinosyl moiety at C3 on ring C. Structural differences regarding the number and position of hydroxyl and glucose moieties as well as structural flexibility could indicate different mechanisms by which these flavonoids influence the activity of adrenal steroidogenic enzymes.

Rooibos influences glucocorticoid levels and steroid ratios in vivo and in vitro: a natural approach in the management of stress and metabolic disorders?

SCOPE: To determine the effect of Rooibos (Aspalathus linearis) on glucocorticoid biosynthesis and inactivation in vivo and in vitro. METHODS AND RESULTS: Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) analyses of in vivo studies showed that human Rooibos consumption increased cortisone plasma levels in males (p = 0.0465) and reduced cortisol:cortisone ratios in males and females (p = 0.0486) at risk for cardiovascular disease. In rats, corticosterone (CORT) (p = 0.0275) and deoxycorticosterone (p = 0.0298) levels as well as the CORT:testosterone ratio (p = 0.0009) decreased following Rooibos consumption. The inactivation of cortisol was investigated in vitro by expressing 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) and type 2 (11ßHSD2) in CHO-K1 cells. Rooibos inhibited 11ßHSD1, which resulted in a significant reduction in the cortisol:cortisone ratio (p < 0.01). No significant effect was detected on 11ßHSD2. In vitro studies in adrenal H295R cells showed that Rooibos and rutin, one of the more stable flavonoid compounds present in Rooibos, significantly reduced the levels of cortisol and CORT in cells stimulated with forskolin to mimic a stress response. CONCLUSION: In vivo studies demonstrate that Rooibos significantly decreased glucocorticoid levels in rats and steroid metabolite ratios linked to metabolic disorders--cortisol:cortisone in humans and CORT:testosterone in rats. Results obtained at cellular level elucidate possible mechanisms by which these effects were achieved.

11ß-hydroxyandrostenedione returns to the steroid arena: biosynthesis, metabolism and function.

The biological significance of 11ß-hydroxyandrostenedione (11OHA4) has eluded researchers for the past six decades. It is now known that 11OHA4 is biosynthesized in the androgen arm of the adrenal steroidogenesis pathway and subsequently metabolized by steroidogenic enzymes in vitro, serving as precursor to recognized and novel androgenic steroids. These in vitro findings extend beyond the adrenal, suggesting that 11OHA4 could be metabolized in steroid-responsive peripheral tissues, as is the case for androgen precursor metabolites of adrenal origin. The significance thereof becomes apparent when considering that the metabolism of 11OHA4 in LNCaP androgen dependent prostate cancer cells yields androgenic steroid metabolites. It is thus possible that 11OHA4 may be metabolized to yield ligands for steroid receptors in not only the prostate but also in other steroid-responsive tissues. Future investigations of 11OHA4 may therefore characterize it as a vital steroid with far-reaching physiological consequences. An overview of the research on 11OHA4 since its identification in 1953 will be presented, with specific focus on the most recent works that have advanced our understanding of its biological role, thereby underscoring its relevance in health and disease.

11ß-Hydroxydihydrotestosterone and 11-ketodihydrotestosterone, novel C19 steroids with androgenic activity: a putative role in castration resistant prostate cancer?

Adrenal C19 steroids, dehydroepiandrostenedione (DHEA(S)) and androstenedione (A4), play a critical role in castration resistant prostate cancer (CRPC) as they are metabolised to dihydrotestosterone (DHT), via testosterone (T), or via the alternate 5α-dione pathway, bypassing T. Adrenal 11OHA4 metabolism in CRPC is, however, unknown. We present a novel pathway for 11OHA4 metabolism in CRPC leading to the production of 11ketoT (11KT) and novel 5α-reduced C19 steroids - 11OH-5α-androstanedione, 11keto-5α-androstanedione, 11OHDHT and 11ketoDHT (11KDHT). The pathway was validated in the androgen-dependent prostate cancer cell line, LNCaP. Androgen receptor (AR) transactivation studies showed that while 11KT and 11OHDHT act as a partial AR agonists, 11KDHT is a full AR agonist exhibiting similar activity to DHT at 1nM. Our data demonstrates that, while 11OHA4 has negligible androgenic activity, its metabolism to 11KT and 11KDHT yields androgenic compounds which may be implicated, together with A4 and DHEA(S), in driving CRPC in the absence of testicular T.

11ß-hydroxyandrostenedione, the product of androstenedione metabolism in the adrenal, is metabolized in LNCaP cells by 5α-reductase yielding 11ß-hydroxy-5α-androstanedione.

11ß-Hydroxyandrostenedione (11OHA4), which is unique to the adrenal, was first isolated from human adrenal tissue in the fifties. It was later shown in the sixties that 11ß-hydroxytestosterone (11OHT) was also produced by the human adrenal. Attention has shifted back to these adrenal androgens once more, as improved analytical techniques have enabled more accurate detection of steroid hormones. In this paper, we investigated the origin of these metabolites as well as their subsequent metabolism and examined a possible physiological role for 11OHA4 in prostate cancer cells. In H295R cells treated with forskolin and trilostane, etomidate, a reported cytochrome P450 11ß-hydroxylase (CYP11B1) inhibitor, blocked the production of corticosterone, cortisol, 11OHA4 and 11OHT. The metabolism of androstenedione and testosterone by CYP11B1 and aldosterone synthase (CYP11B2) was assayed. Androstenedione was converted by CYP11B1, while the conversion by CYP11B2 was negligible. Both enzymes readily converted testosterone. The metabolism of these 11ß-hydroxylated metabolites by 11ß-hydroxysteroid dehydrogenase (11ßHSD) types 1 and 2 was subsequently investigated. 11ßHSD2 catalyzed the conversion of both 11OHA4 and 11OHT to their respective keto-steroids, while 11ßHSD1 catalyzed the conversion of 11-ketoandrostenedione and 11-ketotestosterone to their respective hydroxy-steroids in Chinese hamster ovary cells. Investigating a functional role, steroid 5α-reductase types 1 and 2 converted 11OHA4 to 11ß-hydroxy-5α-androstanedione (11OH-5α-dione), identified by accurate mass detection. UPLC-MS/MS analyses of 11OHA4 metabolism in LNCaP androgen-dependent prostate cancer cells, identified the 5α-reduced metabolite as well as 11-ketoandrostenedione and 11-ketotestosterone, with the latter indicating conversion by 17ß-hydroxysteroid dehydrogenase. Downstream metabolism by 11ßHSD2 and by 5α-reductase may therefore indicate a physiological role for 11OHA4 and/or 11OH-5α-dione in normal and prostate cancer cells.

The influence of Aspalathus linearis (Rooibos) and dihydrochalcones on adrenal steroidogenesis: quantification of steroid intermediates and end products in H295R cells.

The steroid hormone output of the adrenal gland is crucial in the maintenance of hormonal homeostasis, with hormonal imbalances being associated with numerous clinical conditions which include, amongst others, hypertension, metabolic syndrome, cardiovascular disease, insulin resistance and type 2 diabetes. Aspalathus linearis (Rooibos), which has been reported to aid stress-related symptoms linked to metabolic diseases, contains a wide spectrum of bioactive phenolic compounds of which aspalathin is unique. In this study the inhibitory effects of Rooibos and the dihydrochalcones, aspalathin and nothofagin, were investigated on adrenal steroidogenesis. The activities of both cytochrome P450 17α-hydroxylase/17,20 lyase and cytochrome P450 21-hydroxylase were significantly inhibited in COS-1 cells. In order to study the effect of these compounds in H295R cells, a human adrenal carcinoma cell line, a novel UPLC-MS/MS method was developed for the detection and quantification of twenty-one steroid metabolites using a single chromatographic separation. Under both basal and forskolin-stimulated conditions, the total amount of steroids produced in H295R cells significantly decreased in the presence of Rooibos, aspalathin and nothofagin. Under stimulated conditions, Rooibos decreased the total steroid output 4-fold and resulted in a significant reduction of aldosterone and cortisol precursors. Dehydroepiandrosterone-sulfate levels were unchanged, while the levels of androstenedione (A4) and 11ß-hydroxyandrostenedione (11ßOH-A4) were inhibited 5.5 and 2.3-fold, respectively. Quantification of 11ßOH-A4 showed this metabolite to be a major product of steroidogenesis in H295R cells and we confirm, for the first time, that this steroid metabolite is the product of the hydroxylation of A4 by human cytochrome P450 11ß-hydroxylase. Taken together our results demonstrate that Rooibos, aspalathin and nothofagin influence steroid hormone biosynthesis and the flux through the mineralocorticoid, glucocorticoid and androgen pathways, thus possibly contributing to the alleviation of negative effects arising from elevated glucocorticoid levels.