Waltenberger B.,University of Innsbruck |
Schuster D.,University of Innsbruck |
Schuster D.,Inte Ligand GmbH |
Paramapojn S.,Mahidol University |
And 5 more authors.
Phytomedicine | Year: 2011
Prasaplai is a medicinal plant mixture that is used in Thailand to treat primary dysmenorrhea, which is characterized by painful uterine contractility caused by a significant increase of prostaglandin release. Cyclooxygenase (COX) represents a key enzyme in the formation of prostaglandins. Former studies revealed that extracts of Prasaplai inhibit COX-1 and COX-2. In this study, a comprehensive literature survey for known constituents of Prasaplai was performed. A multiconformational 3D database was created comprising 683 molecules. Virtual parallel screening using six validated pharmacophore models for COX inhibitors was performed resulting in a hit list of 166 compounds. 46 Prasaplai components with already determined COX activity were used for the external validation of this set of COX pharmacophore models. 57% of these components were classified correctly by the pharmacophore models. These findings confirm that the virtual approach provides a helpful tool (i) to unravel which molecular compounds might be responsible for the COX-inhibitory activity of Prasaplai and (ii) for the fast identification of novel COX inhibitors. © 2010 Elsevier GmbH.
Fakhrudin N.,University of Vienna |
Fakhrudin N.,Gadjah Mada University |
Ladurner A.,University of Vienna |
Atanasov A.G.,University of Vienna |
And 11 more authors.
Molecular Pharmacology | Year: 2010
Peroxisome proliferator-activated receptor gamma (PPARγ) agonists are used for the treatment of type 2 diabetes and metabolic syndrome. However, the currently used PPARγ agonists display serious side effects, which has led to a great interest in the discovery of novel ligands with favorable properties. The aim of our study was to identify new PPARγ agonists by a PPARγ pharmacophore-based virtual screening of 3D natural product libraries. This in silico approach led to the identification of several neolignans predicted to bind the receptor ligand binding domain (LBD). To confirm this prediction, the neolignans dieugenol, tetrahydrodieugenol, and magnolol were isolated from the respective natural source or synthesized and subsequently tested for PPARγ receptor binding. The neolignans bound to the PPARγ LBD with EC 50 values in the nanomolar range, exhibiting a binding pattern highly similar to the clinically used agonist pioglitazone. In intact cells, dieugenol and tetrahydrodieugenol selectively activated human PPARγ-mediated, but not human PPARα- or -β/δ-mediated luciferase reporter expression, with a pattern suggesting partial PPARγ agonism. The coactivator recruitment study also demonstrated partial agonism of the tested neolignans. Dieugenol, tetrahydrodieugenol, and magnolol but not the structurally related eugenol induced 3T3-L1 preadipocyte differentiation, confirming effectiveness in a cell model with endogenous PPARγ expression. In conclusion, we identified neolignans as novel ligands for PPARγ, which exhibited interesting activation profiles, recommending them as potential pharmaceutical leads or dietary supplements. Copyright © 2010 The American Society for Pharmacology and Experimental Therapeutics.
Kratschmar D.V.,University of Basel |
Vuorinen A.,University of Innsbruck |
Da Cunha T.,University of Basel |
Wolber G.,Free University of Berlin |
And 5 more authors.
Journal of Steroid Biochemistry and Molecular Biology | Year: 2011
Modulation of intracellular glucocorticoid availability is considered as a promising strategy to treat glucocorticoid-dependent diseases. 18β-Glycyrrhetinic acid (GA), the biologically active triterpenoid metabolite of glycyrrhizin, which is contained in the roots and rhizomes of licorice (Glycyrrhiza spp.), represents a well-known but non-selective inhibitor of 11β-hydroxysteroid dehydrogenases (11β-HSDs). However, to assess the physiological functions of the respective enzymes and for potential therapeutic applications selective inhibitors are needed. In the present study, we applied bioassays and 3D-structure modeling to characterize nine 11β-HSD1 and fifteen 11β-HSD2 inhibiting GA derivatives. Comparison of the GA derivatives in assays using cell lysates revealed that modifications at the 3-hydroxyl and/or the carboxyl led to highly selective and potent 11β-HSD2 inhibitors. The data generated significantly extends our knowledge on structure-activity relationship of GA derivatives as 11β-HSD inhibitors. Using recombinant enzymes we found also potent inhibition of mouse 11β-HSD2, despite significant species-specific differences. The selected GA derivatives potently inhibited 11β-HSD2 in intact SW-620 colon cancer cells, although the rank order of inhibitory potential differed from that obtained in cell lysates. The biological activity of compounds was further demonstrated in glucocorticoid receptor (GR) transactivation assays in cells coexpressing GR and 11β-HSD1 or 11β-HSD2. 3D-structure modeling provides an explanation for the differences in the selectivity and activity of the GA derivatives investigated. The most potent and selective 11β-HSD2 inhibitors should prove useful as mechanistic tools for further anti-inflammatory and anti-cancer in vitro and in vivo studies. Article from the Special issue on Targeted Inhibitors. © 2011 Elsevier Ltd. All rights reserved.
PubMed | Inte Ligand GmbH and University of Innsbruck
Type: Journal Article | Journal: Drug discovery today. Technologies | Year: 2014
The most common pharmacophore building concepts based on either 3D structure of the target or ligand information are discussed together with the application of such models as queries for 3D database search. An overview of the key techniques available on the market is given and differences with respect to algorithms used and performance obtained are highlighted. Pharmacophore modelling and 3D database search are shown to be successful tools for enriching screening experiments aimed at the discovery of novel bio-active compounds.:
Seidel T.,Inte Ligand GmbH |
Ibis G.,Inte Ligand GmbH |
Bendix F.,Inte Ligand GmbH |
Wolber G.,Inte Ligand GmbH |
Wolber G.,Free University of Berlin
Drug Discovery Today: Technologies | Year: 2010
3D pharmacophore-based techniques have become one of the most important approaches for the fast and accurate virtual screening of databases with millions of compounds. The success of 3D pharmacophores is largely based on their intuitive interpretation and creation, but the virtual screening with such three-dimensional geometric models still poses a considerable algorithmic and conceptual challenge. Most current implementations favor fast screening speed at the detriment of accuracy. This review describes the general strategies and algorithms employed for 3D pharmacophore searching by some current pharmacophore modeling platforms and will highlight their differences. © 2010 Elsevier Ltd. All rights reserved.