Structure, function and tissue-specific gene expression of 3β-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase enzymes in classical and peripheral intracrine steroidogenic tissues

The membrane-bound enzyme 3β-hydroxysteroid dehydrogenase/5-ene-4-ene isomerase (3β-HSD) catalyses an essential step in the transformation of all 5-pregnen-3β-ol and 5-androsten-3β-ol steroids into the corresponding 3-keto-4-ene-steroids, namely progesterone as well as all the precursors of androgens, estrogens, glucocorticoids and mineralocorticoids. We have recently characterized two types of human 3β-HSD cDNA clones and the corresponding genes which encode type I and II 3β-HSD isoenzymes of 372 and 371 amino acids, respectively, and share 93.5% homology. The human 3β-HSD genes containing 4 exons were assigned by in situ hybridization to the p11-p13 region of the short arm of chromosome 1. Human type I 3β-HSD is the almost exclusive mRNA species present in the placenta and skin while the human type II is the predominant mRNA species in the adrenals, ovaries and testes. The type I protein possesses higher 3β-HSD activity than type II. We elucidated the structures of three types of rat 3β-HSD cDNAs as well that of one type of 3β-HSD from bovine and macaque ovary λgt11 cDNA libraries, which all encode a 372 amino acid protein. The rat type I and II 3β-HSD proteins expressed in the adrenals, gonads and adipose tissue share 93.8% homology. Transient expression of human type I and II as well as rat type I and II 3β-HSD cDNAs in HeLa human cervical carcinoma cells reveals that 3β-ol dehydrogenase and 5-ene-4-ene isomerase activities reside within a single protein. These expressed 3β-HSD proteins convert 3β-hydroxy-5-ene-steroids into 3-keto-4-ene derivatives and catalyze the interconversion of 3β-hydroxy and 3-keto-5α-androstane steroids. By site-directed mutagenesis, we demonstrated that the lower activity of expressed rat type II compared to rat type I 3β-HSD is due to a change of four residues probably involved in a membrane-spanning domain. When homogenates from cells transfected with a plasmid vector containing rat type I 3β-HSD is incubated in the presence of dihydrotestosterone (DHT) using NAD? as co-factor, 5α-androstanedione was formed (A-dione), indicating an intrinsic androgenic 17β-hydroxysteroid dehydrogenase (17β-HSD) activity of this 3β-HSD. We cloned a third type of rat cDNA encoding a predicted type III 3β-HSD specifically expressed in the rat liver, which shares 80% similarity with the two other isoenzymes. Transient expression in human HeLa cells reveals that the type III isoenzyme does not display oxidative activity for the classical substrates of 3β-HSD. However, in common with the type I enzyme, it converts A-dione and DHT to the corresponding 3β-hydroxysteroids, thus showing an exclusive 3-ketosteroid reductase activity. When NADPH is used as co-factor, the affinity for DHT of the type III enzyme becomes 10-fold higher than that of the type I. Rat type III mRNA was below the detection limit in intact female liver. Following hypophysectomy, its concentration increased to 55% of the values measured in intact or hypophysectomized male rats, an increase which can be blocked by administration of ovine prolactin (oPRL). Treatment with oPRL for 10 days starting 15 days after hypophysectomy markedly decreased ovarian 3β-HSD mRNA accumulation accompanied by a similar decrease in 3β-HSD activity and protein levels. Treatment with the gonadotropin hCG reversed the potent inhibitory effect of oPRL on these parameters and stimulated 3β-HSD mRNA levels in ovarian interstitial cells. These data indicate that the presence of multiple 3β-HSD isoenzymes offers the possibility of tissue-specific expression and regulation of this enzymatic activity that plays an essential role in the biosynthesis of all hormonal steroids in classical as well as peripheral intracrine steroidogenic tissues.     

Discovery of 2-methyl-1-{1-[(5-methyl-1H-indol-2-yl)carbonyl]piperidin-4-yl}propan-2-ol: A novel,potent and selective type 5 17β-hydroxysteroid dehydrogenase inhibitor

Type 5 17β-hydroxysteroid dehydrogenase (17β-HSD5), also known as aldo-keto reductase 1C3 (AKR1C3), is a member of the aldo-keto reductase superfamily of enzymes and is expressed in the human prostate. One of the main functions of 17β-HSD5 is to catalyze the conversion of the weak androgen, androstenedione, to the potent androgen, testosterone. The concentration of intraprostatic 5α-dihydrotestosterone (DHT) in patients following chemical or surgical castration has been reported to remain as high as 39% of that of healthy men, with 17β-HSD5 shown to be involved in this androgen synthesis. Inhibition of 17β-HSD5 therefore represents a promising target for the treatment of castration-resistant prostate cancer (CRPC). To investigate this, we conducted high-throughput screening (HTS) and identified compound 2, which displayed a structure distinct from known 17β-HSD5 inhibitors. To optimize the inhibitory activity of compound 2, we first introduced a primary alcohol group. We then converted the primary alcohol group to a tertiary alcohol, which further enhanced the inhibitory activity, improved metabolic stability, and led to the identification of compound 17. Oral administration of compound 17 to castrated nude mice bearing the CWR22R xenograft resulted in the suppression of androstenedione (AD)-induced intratumoral testosterone production. Compound 17 also demonstrated good isoform selectivity, minimal inhibitory activity against either CYP or hERG, and enhanced pharmacokinetic and physicochemical properties.     

Estrogen receptor alpha interacts with 17β-hydroxysteroid dehydrogenase type 10 in mitochondria

Estrogen receptor alpha (ERα) is present in the nucleus, the cytosol and in mitochondria. The rat ERα ligand binding domain was employed as bait in a bacterial two-hybrid screening of a human heart cDNA library to detect novel protein-protein interaction partners of ERα in the heart. 17β-Hydroxysteroid dehydrogenase type 10 (17β-HSD10), which converts potent (17β-estradiol) to less potent estrogens (estrone), co-localized with 17β-HSD10 in the mitochondria of rat cardiac myocytes. GST pull-down experiments confirmed the interaction of ERα and 17β-HSD10. These findings suggest that the ERα estrogen receptor might be involved in regulating intracellular estrogen levels by modulating 17β-HSD10 activity.     

Down‐regulated lncRNA HOTAIR alleviates polycystic ovaries syndrome in rats by reducing expression of insulin‐like growth factor 1 via microRNA‐130a

It has been found that long noncoding RNA HOTAIR, microRNA‐130a (miR‐130a) and insulin‐like growth factor 1 (IGF1) expression are associated with ovarian cancer, thus, we hypothesised that the HOTAIR/miR‐130a/IGF1 axis might associate with endocrine disorders and biological behaviours of ovarian granulosa cells in rat models of polycystic ovary syndrome (PCOS). PCOS rat models were established by injection of dehydro‐isoandrosterone, followed by treatment of si‐HOTAIR, oe‐HOTAIR, miR‐130a mimics or miR‐130a inhibitors. Serum hormonal levels were determined to evaluate endocrine conditions. The effect of HOTAIR and miR‐130a on activities of isolated ovarian granulosa cells was assessed, as well as the involvement of IGF1.In the ovarian tissues and granulosa cells of PCOS rat models, highly expressed HOTAIR and IGF1 and poorly expressed miR‐130a were identified. In response to oe‐HOTAIR, serum levels of E₂, T and LH were increased and serum levels of FSH were reduced; the proliferation of granulosa cells was reduced and apoptosis was promoted; notably, expression of miR‐130a was reduced while expression of IGF1 was increased. The treatment of si‐HOTAIR reversed the situation. Furthermore, the binding of HOTAIR to miR‐130a and targeting relationship of miR‐130a and IGF1 were confirmed. LncRNA HOTAIR up‐regulates the expression of IGF1 and aggravates the endocrine disorders and granulosa cell apoptosis through competitive binding to miR‐130a in rat models of PCOS. Based on our finding, we predict that competitive binding of HOTAIR to miR‐130a may act as a novel target for the molecular treatment of PCOS.     

In vivo activity of 11β-hydroxysteroid dehydrogenase type 1 in man: effects of prednisolone and chenodesoxycholic acid

The 11β-hydroxysteroid dehydrogenases (11β-HSDs) play a pivotal role in glucocorticoid (GC) action. 11β-HSD1 is a predominant reductase, activating GCs from inert metabolites, whereas 11β-HSD2 is a potent dehydrogenase inactivating GCs. Knowing the metabolic effects of GCs, a selective inhibition of 11β-HSD1 represents a potential target for therapy of impaired glucose tolerance, insulin insensitivity and central obesity. In vitro, 11β-HSD1 is selectively inhibited by chenodesoxycholic acid (CDCA) and upregulated under GC exposure. Therefore, we aimed to investigate the effects of CDCA and prednisolone on hepatic 11β-HSD1 activity in vivo by measuring 11-reduction of orally given cortisone (E) acetate to cortisol (F). CDCA or placebo was given to 5 male healthy volunteers within a randomised cross-over trial before and after oral administration of 12.5 mg E acetate at 8:00 h. For measurement of in vivo effects of GCs on 11β-HSD1 activity, hepatic reduction of 25 mg E acetate before and after treatment with prednisolone (30 mg for 6 days) was determined in 7 healthy males. Serum GC levels were determined using a fully automated liquid chromatographic system. CDCA had no effect on the activity of 11β-HSD1 in vivo. Prednisolone therapy leads to a marked rise in serum F concentrations and an elevated F/E serum ratio. This proves GC-induced activation of hepatic 11β-HSD1, which could not be extinguished by a parallel increase of IGF-1 under prednisolone. CDCA does not affect in vivo activity of 11β-HSD1 when given in therapeutic dosages. During GC treatment, increased hepatic activation of E to F may aggravate metabolic side effects of GCs such as seen in the metabolic syndrome.     

Novel estrone mimetics with high 17β-HSD1 inhibitory activity

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the reduction of estrone into estradiol, which is the most potent estrogen in humans. Lowering intracellular estradiol concentration by inhibition of this enzyme is a promising new option for the treatment of estrogen-dependent diseases like breast cancer and endometriosis. Combination of ligand- and structure-based design resulted in heterocyclic substituted biphenylols and their aza-analogs as new 17β-HSD1 inhibitors. The design was based on mimicking estrone, especially focusing on the imitation of the D-ring keto group with (substituted) heterocycles. Molecular docking provided insights into plausible protein–ligand interactions for this class of compounds. The most promising compound 12 showed an inhibitory activity in the high nanomolar range and very low affinity for the estrogen receptors α and β. Thus, compound 12 is a novel tool for the elucidation of the pharmacological relevance of 17β-HSD1 and might be a lead for the treatment of estrogen-dependent diseases.     

Androgen receptors in coeliac ganglion in late pregnant rat

The ovarian function is controlled by endocrine factors and neural influence. In late pregnant rat, androstenedione, from the coeliac ganglion, has a luteotrophic effect in the ex vivo coeliac ganglion-superior ovarian nerve-ovary system. In this work we investigate the presence of androgen receptors in the coeliac ganglion of late pregnant rats by immunohistochemistry. We also explore, from a physiological point of view, the potential participation of these receptors in the androstenedione ganglionic action on progesterone release and metabolism, as well as on nitrites release in the ovary compartment. The coeliac ganglion was isolated after being fixed in situ and immunohistochemistry was performed. In the system, three experimental groups were used with the addition of (a) androstenedione, (b) flutamide, and (c) androstenedione plus flutamide in the ganglion compartment. Progesterone and nitrite concentrations were determined in the ovary compartment at different incubation times. Corpora lutea samples isolated at the end of incubation were used to determine the expressions and activities of the progesterone synthesis (3β-hydroxysteroid-dehydrogenase, 3β-HSD) and degradation (20α-hydroxysteroid-dehydrogenase, 20α-HSD) enzymes. Immunohistochemistry revealed cytoplasmatic androgen receptor immunoreactivity in neural somas in the coeliac ganglion. In the coeliac ganglion-superior ovarian nerve-ovary system, androstenedione addition increased 3β-HSD and decreased 20α-HSD, showed a tendency to decrease 20α-HSD expression, and increased nitrites release in relation to control. Androstenedione plus flutamide decreased progesterone and nitrites release in relation to the androstenedione group. This work demonstrates the presence of androgen receptors in neurons of celiac ganglion and provides evidence for the luteotrophic action of androstenedione via a neural pathway that may be mediated by these receptors.     

Design,synthesis, and biological evaluation of novel selective peptide inhibitors of 11β-hydroxysteroid dehydrogenase 1

The enzyme 11β-HSD1 plays a crucial role in the tissue-specific regulation of cortisol levels and it has been associated with various diseases. Inhibition of 11β-HSD1 is an attractive intervention strategy and the discovery of novel selective 11β-HSD1 inhibitors is of high relevance. In this study, we identified and evaluated a new series of selective peptide 11β-HSD1 inhibitors with potential for skin care applications. This novel scaffold was designed with the aid of molecular modeling and two previously reported inhibitors. SAR optimization yielded highly active peptides (IC₅₀ below 400?nM) that were inactive at 1?µM concentration against structurally related enzymes (11β-HSD2, 17β-HSD1 and 17β-HSD2). The best performing peptides inhibited the conversion of cortisone into cortisol in primary human keratinocytes and the most active compound, 5d, was further shown to reverse cortisone-induced collagen damage in human ex-vivo tissue.     

Identification of chemically diverse, novel inhibitors of 17β-hydroxysteroid dehydrogenase type 3 and 5 by pharmacophore-based virtual screening

17β-Hydroxysteroid dehydrogenase type 3 and 5 (17β-HSD3 and 17β-HSD5) catalyze testosterone biosynthesis and thereby constitute therapeutic targets for androgen-related diseases or endocrine-disrupting chemicals. As a fast and efficient tool to identify potential ligands for 17βHSD3/5, ligand- and structure-based pharmacophore models for both enzymes were developed. The models were evaluated first by in silico screening of commercial compound databases and further experimentally validated by enzymatic efficacy tests of selected virtual hits. Among the 35 tested compounds, 11 novel inhibitors with distinct chemical scaffolds, e.g. sulfonamides and triazoles, and with different selectivity properties were discovered. Thereby, we provide several potential starting points for further 17β-HSD3 and 17β-HSD5 inhibitor development. Article from the Special issue on Targeted Inhibitors.     

Synthesis and 11β hydroxysteroid dehydrogenase 1 inhibition of thiazolidine derivatives with an adamantyl group

A new series of thiazolidine derivatives with an adamantyl group was synthesized and evaluated for their ability to inhibit 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1). Our initial compound 5a showed a weak inhibitory activity. Significant improvements in potency were achieved by substituent modification. The potent compound 8g (E) showed good in vitro inhibitory activity toward human 11β-HSD1, selectivity toward 11β-HSD2, metabolic stability, pharmacokinetic, and safety profile. Furthermore, this compound significantly inhibited 11β-HSD1 activity in rat and monkey models, and showed improved glycemic control in KKAy mice.     

Molecular mechanisms of insulin resistance in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy of unknown aetiology that affects women of reproductive age. During the past ten years, defective insulin activity in PCOS has been demonstrated in target tissues and causes insulin resistance and hyperinsulinaemia. Furthermore, presence of insulin receptors in the ovarian tissue and overproduction of androgens by theca cells leads to characteristic hyperandrogenaemia. Recent data suggest a divergence in post-receptor signalling pathways for insulin in its target tissues (muscle, adipocytes and ovarian tissue), where the metabolic pathway of insulin activity is defective, whereas the activation of steroidogenesis is maintained. Investigators are still searching for clues to understand the cause of this enigmatic syndrome, despite great advances in molecular medicine and genetics.     

Curcumin derivatives inhibit testicular 17β-hydroxysteroid dehydrogenase 3

Non-steroidal compounds that inhibit 17β-hydroxysteroid dehydrogenase isoform 3 (17β-HSD3), an enzyme catalyzing the final step in testosterone biosynthesis in Leydig cells, are under development for male contraceptive or treatment of androgen dependent diseases including prostate cancer. A series of curcumin analogues with more stable chemical structures were compared to curcumin as inhibitors of 17β-HSD3 in rat intact Leydig cells as well as rat and human testis microsomes.     

The Role of Heat Shock Protein 90B1 in Patients with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a heterogenetic disorder in women that is characterized by arrested follicular growth and anovulatory infertility. The altered protein expression levels in the ovarian tissues reflect the molecular defects in folliculogenesis. To identify aberrant protein expression in PCOS, we analyzed protein expression profiles in the ovarian tissues of patients with PCOS. We identified a total of 18 protein spots that were differentially expressed in PCOS compared with healthy ovarian samples. A total of 13 proteins were upregulated and 5 proteins were downregulated. The expression levels of heat shock protein 90B1 (HSP90B1) and calcium signaling activator calmodulin 1 (CALM1) were increased by at least two-fold. The expression levels of HSP90B1 and CALM1 were positively associated with ovarian cell survival and negatively associated with caspase-3 activation and apoptosis. Knock-down of HSP90B1 with siRNA attenuated ovarian cell survival and increased apoptosis. In contrast, ovarian cell survival was improved and cell apoptosis was decreased in cells over-expressing HSP90B1. These results demonstrated the pivotal role of HSP90B1 in the proliferation and survival of ovarian cells, suggesting a critical role for HSP90B1 in the pathogenesis of PCOS. We also observed a downregulation of anti-inflammatory activity-related annexin A6 (ANXA6) and tropomyosin 2 (TPM2) compared with the normal controls, which could affect cell division and folliculogenesis in PCOS. This is the first study to identify novel altered gene expression in the ovarian tissues of patients with PCOS. These findings may have significant implications for future diagnostic and treatment strategies for PCOS using molecular interventions.     

Synthesis of new glycyrrhetinic acid derived ring A azepanone, 29-urea and 29-hydroxamic acid derivatives as selective 11β-hydroxysteroid dehydrogenase 2 inhibitors

Glycyrrhetinic acid, the metabolite of the natural product glycyrrhizin, is a well known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and type 2. Whereas inhibition of 11β-HSD1 is currently under consideration for treatment of metabolic diseases, such as obesity and diabetes, 11β-HSD2 inhibitors may find therapeutic applications in chronic inflammatory diseases and certain forms of cancer. Recently, we published a series of hydroxamic acid derivatives of glycyrrhetinic acid showing high selectivity for 11β-HSD2. The most potent and selective compound is active against human 11β-HSD2 in the low nanomolar range with a 350-fold selectivity over human 11β-HSD1. Starting from the lead compounds glycyrrhetinic acid and the hydroxamic acid derivatives, novel triterpene type derivatives were synthesized and analyzed for their biological activity against overexpressed human 11β-HSD1 and 11β-HSD2 in cell lysates. Here we describe novel 29-urea- and 29-hydroxamic acid derivatives of glycyrrhetinic acid as well as derivatives with the Beckman rearrangement of the 3-oxime to a seven-membered ring, and the rearrangement of the C-ring from 11-keto-12-ene to 12-keto-9(11)-ene. The combination of modifications on different positions led to compounds comprising further improved selective inhibition of 11β-HSD2 in the lower nanomolar range with up to 3600-fold selectivity.     

Discovery of highly potent, nonsteroidal 17β-hydroxysteroid dehydrogenase type 1 inhibitors by virtual high-throughput screening

17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the formation of the potent proliferation-stimulating hormone estradiol, and it is thus involved in the development of hormone-dependent breast cancer. Due to its high substrate specificity and the known relationships between its overexpression and disease incidence, 17β-HSD1 is considered an attractive target for drug development. Here, we have used structure-based virtual high-throughput screening to successfully identify potent nonsteroidal 17β-HSD1 inhibitors. Computational screening of a drug-like database containing 13 million compounds identified hits with a 2-benzylidenebenzofuran-3(2H)-one scaffold that we show to be highly potent 17β-HSD1 inhibitors. The most potent in the series, compound 1, showed an IC(50) of 45nM in our 17β-HSD1 inhibition assay, and also showed good selectivity for 17β-HSD1 over 17β-HSD2.     

Synthesis of novel 3-amino and 29-hydroxamic acid derivatives of glycyrrhetinic acid as selective 11β-hydroxysteroid dehydrogenase 2 inhibitors

Glycyrrhetinic acid, the metabolite of the natural product glycyrrhizin, is a well known nonselective inhibitor of 11β-hydroxysteroid dehydrogenase (11β-HSD) type 1 and type 2. Whereas inhibition of 11β-HSD1 is currently under consideration for treatment of metabolic diseases, such as obesity and diabetes, 11β-HSD2 inhibitors may find therapeutic applications in chronic inflammatory diseases and certain forms of cancer. So far, no selective 11β-HSD2 inhibitor has been developed and neither animal studies nor clinical trials have been reported based on 11β-HSD2 inhibition. Starting from the lead compound glycyrrhetinic acid, novel triterpene type derivatives were synthesized and analyzed for their biological activity against overexpressed human 11β-HSD1 and 11β-HSD2 in cell lysates. Several hydroxamic acid derivatives showed high selectivity for 11β-HSD2. The most potent and selective compound is active against human 11β-HSD2 in the low nanomolar range with a 350-fold selectivity over human 11β-HSD1.     

Effects of myo-inositol in women with PCOS: a systematic review of randomized controlled trials

Polycystic ovary syndrome (PCOS) affects 5%-10% of women in reproductive age, and it is the most common cause of infertility due to ovarian dysfunction and menstrual irregularity. Several studies have reported that insulin resistance is common in PCOS women, regardless of the body mass index. The importance of insulin resistance in PCOS is also suggested by the fact that insulin-sensitizing compounds have been proposed as putative treatments to solve the hyperinsulinemia-induced dysfunction of ovarian response to endogenous gonadotropins. Rescuing the ovarian response to endogenous gonadotropins reduces hyperandrogenemia and re-establishes menstrual cyclicity and ovulation, increasing the chance of a spontaneous pregnancy. Among the insulin-sensitizing compounds, there is myo-inosiol (MYO). Previous studies have demonstrated that MYO is capable of restoring spontaneous ovarian activity, and consequently fertility, in most patients with PCOS. With the present review, we aim to provide an overview on the clinical outcomes of the MYO use as a treatment to improve ovarian function and metabolic and hormonal parameters in women with PCOS.     

Effects of phthalates on 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase 3 activities in human and rat testes

The 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) are involved in the reactions that culminate in androgen biosynthesis in Leydig cells. Human and rat testis microsomes were used to investigate the inhibitory potencies on 3β-HSD and 17β-HSD3 activities of 14 different phthalates with various carbon numbers in the ethanol moiety. The results demonstrated that the half-maximal inhibitory concentrations (IC(50)s) of dipropyl (DPrP), dibutyl (DBP), dipentyl (DPP), bis(2-butoxyethyl) (BBOP) and dicyclohexyl (DCHP) phthalate were 123.0, 24.1, 25.5, 50.3 and 25.5μM for human 3β-HSD activity, and 62.7, 30.3, 33.8, 82.6 and 24.7μM for rat 3β-HSD activity, respectively. However, only BBOP and DCHP potently inhibited human (IC(50)s, 23.3 and 8.2μM) and rat (IC(50)s, 30.24 and 9.1μM) 17β-HSD3 activity. Phthalates with 1-2 or 7-8 carbon atoms in ethanol moieties had no effects on both enzyme activities even at concentrations up to 1mM. The mode of action of DCHP on 3β-HSD activity was competitive with the substrate pregnenolone but noncompetitive with the cofactor NAD+. The mode of action of DCHP on 17β-HSD3 activity was competitive with the substrate androstenedione but noncompetitive with the cofactor NADPH. In summary, our results showed that there are clear structure-activity responses for phthalates in the inhibition of both 3β-HSD and 17β-HSD3 activities. The length of carbon chains in the ethanol moieties of phthalates may determine the potency to inhibit these two enzymes.     

Mono-carbonyl curcumin analogues as 11β-hydroxysteroid dehydrogenase 1 inhibitors

A series of structurally novel mono-carbonyl curcumin analogues have been synthesized and biologically evaluated to test their inhibitory potencies and the structure–activity relationship (SAR) on human and rat 11β-hydroxysteroid dehydrogenase isoform (11β-HSD1) activities. 11β-HSD1 selective inhibitors have been discovered and compound A10 is discovered as a very potent with an IC₅₀ value of 97 nM without inhibiting 11β-HSD2.