Development and application of a scintillation proximity assay (SPA) for identification of selective inhibitors of 11beta-hydroxysteroid dehydrogenase type 1

Triterpenoids with multi-skeletons as 11 β -HSD1 inhibitors from Euphorbia sikkimensis

An exploration for 11β-HSD1 inhibitors from the whole plant of Euphorbia sikkimensis led to the identification of 10 undescribed triterpenoids 1-10, as well as 7 known triterpenoids (11-17). Their structures were determined by a combination of spectrum elucidations, conformational analyses and quantum chemical calculations. (23E)-25-methoxy-eupha-14,23-diene-3β,7α-diol (1) and (23E)-3β-dihydroxy-27-noreupha-7,23-diene-25-one (2) are two rare cases that feature a rearrangement of Me-30 (14 → 8) and a degradation of Me-27, respectively, in the euphane-type triterpenoid family. It is an interesting phenomenon that (23E)-3β-hydroxy-25-methoxy-eupha-8,23-diene-7-one (4) and (23E)-3β-hydroxy-25-methoxy-lanost-8,23-diene-7-one (5) coexist in the same plant, sharing the same planar structure but belonging to different structural types of triterpenoids. Compounds 3-5 and 14 show significant inhibitory activity against 11β-HSD1 with IC₅₀ values of 6.50 ± 0.22, 1.31 ± 0.34, 9.38 ± 0.64, and 8.27 ± 0.33 μM, respectively. The structure-activity relationship study shows that the euphane-type triterpenoids exhibit the best inhibitory activity, which is in accord with the fact of the euphane-type triterpenoids having the best ability to bind to the active pocket of 11β-HSD1 in the molecular docking experiments.

Development and structure-activity relationships of tanshinones as selective 11β-hydroxysteroid dehydrogenase 1 inhibitors

11β-Hydroxysteroid dehydrogenase 1 (11β-HSD1) represents a promising drug target for metabolic syndrome, including obesity and type 2 diabetes. Our initial screen of a collection of natural products from Danshen led to the identification of tanshinones as the potent and selective 11β-HSD1 inhibitors. To improve the druggability and explore the structure-activity relationships (SARs), more than 40 derivatives have been designed and synthesized using tanshinone IIA and cryptotanshinone as the starting materials. More than 10 derivatives exhibited potent in vitro 11β-HSD1 inhibitory activity and good selectivity over 11β-HSD2 across human and mouse species. Based on the biological results, SARs were further discussed, which was also partially rationalized by a molecular docking model of 1 bound to the 11β-HSD1. Remarkably, compounds 1, 17 and 30 significantly inhibited 11β-HSD1 in 3T3-L1 adipocyte and in livers of ob/ob mice, which merits further investigations as anti-diabetic agents. This study not only provides a series of novel selective 11β-HSD1 inhibitors with promising therapeutic potentials in metabolic syndromes, but also expands the boundaries of the chemical and biological spaces of tanshinones.

Limonoids and Triterpenoids as 11β-HSD1 Inhibitors from Walsura robusta

Nine new cedrelone-type limonoid derivatives, walsunoids A-I (1-9), and 11 known compounds were isolated from the leaves of Walsura robusta. Walsunoid A (1) is a new degradation product of cedrelone-type limonoids, and walsunoid I (9) is a rare cedrelone-type limonoid amide. Their structures and absolute configurations were determined by spectroscopic data, single-crystal X-ray diffraction, and ECD data analyses. Five compounds showed moderate inhibitory activities against human and/or mouse 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with IC50 values ranging from 0.69 to 9.9 μM.

UFSRAT: Ultra-fast Shape Recognition with Atom Types--the discovery of novel bioactive small molecular scaffolds for FKBP12 and 11βHSD1

MOTIVATION

Using molecular similarity to discover bioactive small molecules with novel chemical scaffolds can be computationally demanding. We describe Ultra-fast Shape Recognition with Atom Types (UFSRAT), an efficient algorithm that considers both the 3D distribution (shape) and electrostatics of atoms to score and retrieve molecules capable of making similar interactions to those of the supplied query.

RESULTS

Computational optimization and pre-calculation of molecular descriptors enables a query molecule to be run against a database containing 3.8 million molecules and results returned in under 10 seconds on modest hardware. UFSRAT has been used in pipelines to identify bioactive molecules for two clinically relevant drug targets; FK506-Binding Protein 12 and 11β-hydroxysteroid dehydrogenase type 1. In the case of FK506-Binding Protein 12, UFSRAT was used as the first step in a structure-based virtual screening pipeline, yielding many actives, of which the most active shows a KD, app of 281 µM and contains a substructure present in the query compound. Success was also achieved running solely the UFSRAT technique to identify new actives for 11β-hydroxysteroid dehydrogenase type 1, for which the most active displays an IC50 of 67 nM in a cell based assay and contains a substructure radically different to the query. This demonstrates the valuable ability of the UFSRAT algorithm to perform scaffold hops.

AVAILABILITY AND IMPLEMENTATION

A web-based implementation of the algorithm is freely available at http://opus.bch.ed.ac.uk/ufsrat/.

Ricinodols A–G: new tetracyclic triterpenoids as 11β-HSD1 inhibitors from Ricinodendron heudelotii

Chemical investigation of Ricinodendron heudelotii has returned seven new tetracyclic triterpenoids with moderate to significant inhibitory effect against 11β-HSD1 enzyme.

Lithocarpic Acids A-N, 3,4-seco-Cycloartane Derivatives from the Cupules of Lithocarpus polystachyus

Fourteen new 3,4-seco-cycloartane-type triterpenes, lithocarpic acids A-N (1-14), together with one known compound, coccinetane E (15), were identified from the cupules of Lithocarpus polystachyus. The structures of 1-14 were determined by spectroscopic data analysis and chemical methods, and the absolute configurations of 1 and 4 were defined unequivocally by X-ray crystallography using Cu Kα radiation. Compounds 1-15 are the first examples of 3,4-seco-cycloartane derivatives isolated from the genus Lithocarpus. Among them, compounds 1 and 2, 9 and 10, and 11 and 12 were found to be three pairs of C-24 epimers, while compounds 7 and 8 represent the first examples of 3,4-seco-norcycloartane-type triterpenes. Compound 1, as the major component of the plant extract, showed potent antibacterial activity against Micrococcus luteus and Bacillus subtilis, with MIC values of 3.1 and 6.3 μg/mL, respectively, as well as inhibitory activity against human and mouse 11β-hydroxysteroid dehydrogenase type 1, with IC50 values of 1.9 and 0.24 μM, respectively.

Dammarane-type triterpenoids as 11β-HSD1 inhibitors from Homonoia riparia

An exploration for 11β-HSD1 inhibitors from Homonoia riparia returned eight new dammarane-type triterpenoids, horipenoids A–H (1–8), and a known oleanane-type triterpenoid (9). Their structures were elucidated on the basis of comprehensive analysis of spectroscopic data, and the absolute configuration of horipenoid E (5) was established by single crystal X-ray crystallography. Compounds 1–4 represent a rare class of octanortriterpenoids. Horipenoids C (3) and E (5) showed potent inhibition against mouse 11β-HSD1 with IC50 values of 0.810 ± 0.058 and 0.898 ± 0.215 μM, respectively.

Ingol-type diterpenes from Euphorbia antiquorum with mouse 11β-hydroxysteroid dehydrogenase type 1 inhibition activity

Eighteen new ingol-type diterpenes, euphorantins A-R (1-18), along with four known analogues (19-22), were isolated from the aerial parts of Euphorbia antiquorum. Compounds 1-3 are the first examples of C-17-oxygenated ingol-type diterpenes, and compounds 16-18 represent a rare class of 2,3-di-epimers of ingols. Diterpenes 1, 14, and 22 exhibited inhibitory activities against mouse 11β-HSD1 with IC50 values of 12.0, 6.4, and 0.41 μM, respectively.

New rearranged limonoids from Walsura cochinchinensis

This paper describes the discovery of a rare class of rearranged limonoids from Walsura cochinchinensis.

11β-HSD1 inhibitors from Walsura cochinchinensis

A search for inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) from Walsura cochinchinensis yielded 10 new limonoids, cochinchinoids A-J (1-10), and two new triterpenoids, 3-epimesendanin S (11) and cochinchinoid K (12). Their structures were assigned on the basis of spectroscopic data, with the absolute configurations of 1 and 12 being established by X-ray diffraction analysis. Of these compounds, cochinchinoid K (12) displayed inhibitory activity against mouse 11β-HSD1 with an IC50 value of 0.82 μM.

Chronic inhibition of 11 β -hydroxysteroid dehydrogenase type 1 activity decreases hypertension, insulin resistance, and hypertriglyceridemia in metabolic syndrome

Metabolic syndrome is a constellation of risk factors including hypertension, dyslipidemia, insulin resistance, and obesity that promote the development of cardiovascular disease. Metabolic syndrome has been associated with changes in the secretion or metabolism of glucocorticoids, which have important functions in adipose, liver, kidney, and vasculature. Tissue concentrations of the active glucocorticoid cortisol are controlled by the conversion of cortisone to cortisol by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). Because of the various cardiovascular and metabolic activities of glucocorticoids, we tested the hypothesis that 11β-HSD1 is a common mechanism in the hypertension, dyslipidemia, and insulin resistance in metabolic syndrome. In obese and lean SHR/NDmcr-cp (SHR-cp), cardiovascular, metabolic, and renal functions were measured before and during four weeks of administration of vehicle or compound 11 (10 mg/kg/d), a selective inhibitor of 11β-HSD1. Compound 11 significantly decreased 11β-HSD1 activity in adipose tissue and liver of SHR-cp. In obese SHR-cp, compound 11 significantly decreased mean arterial pressure, glucose intolerance, insulin resistance, hypertriglyceridemia, and plasma renin activity with no effect on heart rate, body weight gain, or microalbuminuria. These results suggest that 11β-HSD1 activity in liver and adipose tissue is a common mediator of hypertension, hypertriglyceridemia, glucose intolerance, and insulin resistance in metabolic syndrome.

Design and synthesis of (R)-1-arylsulfonylpiperidine-2-carboxamides as 11β-hydroxysteroid dehydrogenase type 1 inhibitors

R adamantly beats S: 11β-HSD1 is a target for treating metabolic syndrome. The R isomer 5 was selected as a starting point for optimization and SAR studies. Inhibitor 8 w emerged after several rounds of optimization, showing cross-species inhibition of human and mouse 11β-HSD1. It also displays a good DMPK profile in vitro, and was advanced to PK/PD evaluations in vivo. The results confirmed its dose-dependent activity in mice.

Discovery of 2-Alkyl-1-arylsulfonylprolinamides as 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitors

On the basis of scaffold hopping, a novel series of 2-alkyl-1-arylsulfonylprolinamides was discovered as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) inhibitors. A representative compound 4ek, obtained through SAR and structure optimization studies, demonstrates excellent in vitro potency against 11β-HSD-1 and dose-dependent in vivo inhibition of 11β-HSD-1 in a prednisone/prednisolone transformation biomarker study in mice.

Discovery of novel sulfonamides as potent and selective inhibitors against human and mouse 11β-hydroxysteroid dehydrogenase type 1

Several classes of non-steroid 11β-HSD1 inhibitors have been developed as promising treatments for Type 2 Diabetes (T2D). Using a human 11β-HSD1 selective inhibitor as a starting point, we designed and synthesized a new class of derivatives of 1-arylsulfonyl piperidine-3-carboxamides. It was found that the large lipophilic group on the amino moiety may lead to cross-species potency towards human and mouse, allowing drug development by evaluating compounds in rodent model. By exploring structure-activity-relationship, the (R)-(+)-bornylamine derivative is identified as the most potent inhibitor of mouse enzyme 11β-HSD1 with an IC(50) of 18 nM. Docking studies revealed the different possible interaction modes of the S-enantiomer and R-enantiomer bound to h11β-HSD1, and explained why the S-enantiomer is more active than the R-enantiomer. Finally, two potent and isoform-selective compounds, (+)-isopinocampheylamine derivative 8m and (R)-(+)-bornylamine derivative 8l, with suitable in vitro properties, could be selected for future PK/PD evaluation in rodent models. Then, 8l was subjected a pharmacodynamics study in vivo with rodent model. It was shown that 8l have 71% and 63% inhibition in adipose and liver tissue at 1h after administration, but it was a short-acting compound displaying a significant drop in potency in the subsequent 3h. This study not only provides compounds as novel h11β-HSD1 inhibitors, but also presents structure-activity relationships for designing potent human/mouse 11β-HSD1 inhibitors suitable for in vivo evaluation in rodent models.

Emodin, a natural product, selectively inhibits 11beta-hydroxysteroid dehydrogenase type 1 and ameliorates metabolic disorder in diet-induced obese mice

BACKGROUND AND PURPOSE

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is an attractive therapeutic target of type 2 diabetes and metabolic syndrome. Emodin, a natural product and active ingredient of various Chinese herbs, has been demonstrated to possess multiple biological activities. Here, we investigated the effects of emodin on 11beta-HSD1 and its ability to ameliorate metabolic disorders in diet-induced obese (DIO) mice.

EXPERIMENTAL APPROACH

Scintillation proximity assay was performed to evaluate inhibition of emodin against recombinant human and mouse 11beta-HSDs. The ability of emodin to inhibit prednisone- or dexamethasone-induced insulin resistance was investigated in C57BL/6J mice and its effect on metabolic abnormalities was observed in DIO mice.

KEY RESULTS

Emodin is a potent and selective 11beta-HSD1 inhibitor with the IC(50) of 186 and 86 nM for human and mouse 11beta-HSD1, respectively. Single oral administration of emodin inhibited 11beta-HSD1 activity of liver and fat significantly in mice. Emodin reversed prednisone-induced insulin resistance in mice, whereas it did not affect dexamethasone-induced insulin resistance, which confirmed its inhibitory effect on 11beta-HSD1 in vivo. In DIO mice, oral administration of emodin improved insulin sensitivity and lipid metabolism, and lowered blood glucose and hepatic PEPCK, and glucose-6-phosphatase mRNA.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated a new role for emodin as a potent and selective inhibitor of 11beta-HSD1 and its beneficial effects on metabolic disorders in DIO mice. This highlights the potential value of analogues of emodin as a new class of compounds for the treatment of metabolic syndrome or type 2 diabetes.

Emodin, a natural product, selectively inhibits 11beta-hydroxysteroid dehydrogenase type 1 and ameliorates metabolic disorder in diet-induced obese mice

BACKGROUND AND PURPOSE

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is an attractive therapeutic target of type 2 diabetes and metabolic syndrome. Emodin, a natural product and active ingredient of various Chinese herbs, has been demonstrated to possess multiple biological activities. Here, we investigated the effects of emodin on 11beta-HSD1 and its ability to ameliorate metabolic disorders in diet-induced obese (DIO) mice.

EXPERIMENTAL APPROACH

Scintillation proximity assay was performed to evaluate inhibition of emodin against recombinant human and mouse 11beta-HSDs. The ability of emodin to inhibit prednisone- or dexamethasone-induced insulin resistance was investigated in C57BL/6J mice and its effect on metabolic abnormalities was observed in DIO mice.

KEY RESULTS

Emodin is a potent and selective 11beta-HSD1 inhibitor with the IC(50) of 186 and 86 nM for human and mouse 11beta-HSD1, respectively. Single oral administration of emodin inhibited 11beta-HSD1 activity of liver and fat significantly in mice. Emodin reversed prednisone-induced insulin resistance in mice, whereas it did not affect dexamethasone-induced insulin resistance, which confirmed its inhibitory effect on 11beta-HSD1 in vivo. In DIO mice, oral administration of emodin improved insulin sensitivity and lipid metabolism, and lowered blood glucose and hepatic PEPCK, and glucose-6-phosphatase mRNA.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated a new role for emodin as a potent and selective inhibitor of 11beta-HSD1 and its beneficial effects on metabolic disorders in DIO mice. This highlights the potential value of analogues of emodin as a new class of compounds for the treatment of metabolic syndrome or type 2 diabetes.

Derivatives of (phenylsulfonamido-methyl)nicotine and (phenylsulfonamido-methyl)thiazole as novel 11beta-hydroxysteroid dehydrogenase type 1 inhibitors: synthesis and biological activities in vitro

AIM

To design and synthese a novel class of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) inhibitors, featuring the (phenylsulfonamido-methyl)pyridine and (phenylsulfonamido-methyl)thiazole framework.

METHODS

Our initial lead 4-(phenylsulfonamido-methyl)benzamides were modified. Inhibition of human and mouse 11beta-HSD1 enzymatic activities by the new compounds was determined by a scintillation proximity assay (SPA) using microsomes containing 11beta-HSD1.

RESULTS

Sixteen new compounds (6a-6h, 7a-7h) were designed, synthesized and bioassayed. In dose-response studies, several compounds showed strong inhibitory activities with IC50 values at nanomolar or low nanomolar concentrations. Structure-activity relationships are also discussed with respect to molecular docking results.

CONCLUSION

This study provides two promising new templates for 11beta-HSD1 inhibitors.

11beta-Hydroxysteroid dehydrogenase 1 reductase activity is dependent on a high ratio of NADPH/NADP(+) and is stimulated by extracellular glucose

To assess the impact of the NADPH/NADP(+) ratio and the influence of extracellular glucose on 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) activity, we applied microsomal preparations and intact HEK-293 cells expressing 11beta-HSD1 in the presence or absence of hexose-6-phosphate dehydrogenase (H6PDH). A NADPH/NADP(+) ratio of ten or higher was required for efficient microsomal 11beta-HSD1 reductase activity. Measurements in intact cells suggested that the ER-luminal NADPH concentration is highly sensitive to fluctuating extracellular glucose levels. Lowering glucose in the culture medium dose-dependently decreased 11beta-HSD1 reductase activity and diminished the cortisol/cortisone ratio measured after 24h of incubation. Coexpression with H6PDH potentiated 11beta-HSD1 reductase activity at high glucose. This effect was significantly decreased at low glucose, with concomitantly increased 11beta-HSD1 dehydrogenase activity. In contrast, 11beta-HSD1 reductase activity in H4IIE liver cells and in 3T3-L1 adipocytes was less sensitive to changes in the medium. 11beta-HSD1 dehydrogenase activity was observed in H4IIE cells only at subphysiological glucose levels, indicating a highly efficient supply of substrate for H6PDH and NADPH generation in the ER-lumen. Our results suggest significant cell type-specific differences in ER-luminal NADPH generation that might allow a fine-tuned regulation of glucocorticoid action.

Discovery of novel inhibitors of 11beta-hydroxysteroid dehydrogenase type 1 by docking and pharmacophore modeling

11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is a potential target for treatment of diabetes and metabolic syndrome. Docking and pharmacophore modeling have been used to discover novel inhibitors of 11beta-HSD1. Several compounds, with large structural diversity and good potency against 11beta-HSD1, have been found and their potency was determined by the enzyme assay. New scaffolds of 11beta-HSD1 inhibitors are also reported.

High capacity homogeneous non-radioactive cortisol detection assays for human 11beta-hydroxysteroid dehydrogenase type 1

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes the interconversion of inert glucocorticoid (cortisone) to the active glucocorticoid (cortisol) and is enriched in liver and fat tissues. Increasing evidence suggests that selective inhibition of 11beta-HSD1 may reduce the excess glucocorticoid levels that underlie the etiology of many common disorders that constitute the metabolic syndrome. Measurement of 11beta-HSD1 activity has historically involved the detection of cortisol by methods unfavorable for large-scale screening, such as high performance liquid chromatography or thin layer chromatography. Here we describe the development and validation of novel homogeneous time-resolved fluorescence resonance energy transfer (TR-FRET) and electrochemiluminescence assays for the measurement of cortisol. These non-radioactive assays were easy to perform and produced robust results with reference compound values comparable to those obtained by conventional methods. The TR-FRET assay was easily automated and was successfully employed for the high-throughput screening of a large compound library for inhibitors of purified human recombinant 11beta-HSD1.

Improved Homogeneous Proximity-Based Screening Assay of Potential Inhibitors of 17β-Hydroxysteroid Dehydrogenases

17beta-Hydroxysteroid dehydrogenases (17beta-HSDs) are substrate- and tissue-specific isoenzymes that regulate activation and inactivation of steroid hormones. Up-regulation and downregulation in expression of 17beta-HSDs are linked to onset of many steroid-dependent diseases, such as colon, prostate, and breast cancer; thus 17beta-HSDs are potential drug screening targets. Currently their enzymatic activities are usually measured using laborious chromatographic separations followed by radioactive detection of substrate and product. We have previously reported the use of a homogeneous luminescence resonance energy transfer-based immunoassay for 17beta-estradiol in screening of potential inhibitors of 17beta-HSD type 1 (17beta-HSD-1). By replacing the previously used cell-based enzyme reactions with recombinant enzyme reactions the sensitivity of the screening assay improved considerably. In addition, the single assay was able to detect the influence of a tested compound not only on 17beta-HSD-1 but also on 17beta-HSD type 2 (17beta-HSD-2), catalyzing the opposite reaction. The screening results of the tested molecules obtained from the optimized immunoassay were very similar when compared with the results of high performance liquid chromatography separation analysis. The Z factors were 0.79 and 0.83 for 17beta-HSD-1 and 17beta-HSD-2 assays, respectively. Thus the immunoassay measuring samples converted with the recombinant enzymes was a very suitable method for primary high throughput screening, and it could be used also in further characterization of potential drugs.

Detection of competitive enzyme inhibition with end point progress curve data

A model for a dimensionless factor, the inhibition detection limit (IDL), which describes the limit of detection of competitive inhibition for end point assays as a function of the proportion of substrate converted into product, has been developed. For a given end point enzymatic assay, the IDL function has a maximum that is dependent on the error structure parameters (four parameters) of the assay, the value of [S]o/K(ms), and the extent of product inhibition (K(ms)/K(mp)). Accordingly, the substrate conversion level that maximized the ability to detect samples with high Ki/[I] ratios was predicted for each member of a population of simulated assays. Furthermore, we identified a consensus substrate conversion level where the probability of a near-optimal robustness and detection limit for all the members of the assay population is maximal. Unlike the optimal substrate conversion level for individual assays, this consensus substrate conversion level was dependent only on [S]o/K(m), K(ms)/K(mp), and whether the signal increases or decreases during the course of the reaction. Consensus substrate conversion levels were beyond the initial velocity range for almost all the analyzed assay populations. It was shown that the IDL factor was a more informative indicator of assay quality than the popular Z' factor.

High-Throughput Screening of 11β-Hydroxysteroid Dehydrogenase Type 1 in Scintillation Proximity Assay Format

11beta-Hydroxysteroid dehydrogenase type-1 (11beta-HSD1) is a potential target for the treatment of diabetes, obesity, and hyperlipidemia. This enzyme is mainly responsible for reactivating glucocorticoid hormone inside cells such as adipose cells and liver cells by converting the inactive cortisone to active cortisol. Enzyme assays for 11beta-HSD1 involve either a thin-layer chromatography or high-performance liquid chromatography step to separate cortisol from the substrate cortisone. This additional step is labor intensive and increases the assay time, which limits assay throughput. A homogenous scintillation proximity assay-based method has been recently developed that enables high-throughput screening of 11beta-HSD1 inhibitors. We have applied this novel 11beta-HSD1 assay to screening a large-size compound collection and identified several structural classes of lead compounds that selectively inhibit the activity of 11beta-HSD1.