Identification of the fungicide epoxiconazole by virtual screening and biological assessment as inhibitor of human 11β-hydroxylase and aldosterone synthase. Issue 192 (September 2019)

• Record Type: Journal Article
• Authors: Akram, Muhammad; Patt, Melanie; Kaserer, Teresa; Temml, Veronika; Waratchareeyakul, Watcharee; Kratschmar, Denise V.; Haupenthal, Joerg; Hartmann, Rolf W.; Odermatt, Alex; Schuster, Daniela
• Is Part Of: Journal of steroid biochemistry and molecular biology. Issue 192(2019)
• Publication Date: 2019-09
• Subjects: EDCs endocrine disrupting chemicals -- ACTH adrenocorticotrophic hormone -- CYP11B1 11β-hydroxylase -- DOC 11-deoxycorticosterone -- CAH congenital adrenal hyperplasia -- Na+ sodium -- K+ potassium -- CYP450 cytochrome P450 -- CYP11B2 aldosterone synthase -- ID50 infectious dose -- 3β-HSD 3β-hydroxysteroid dehydrogenase -- PCBs polychlorinated biphenyls -- VS virtual screening -- 3D three dimensional -- HBD hydrogen bond donors -- HBA hydrogen bond acceptors -- AR aromatic ring interactions -- XVOLs exclusion volumes -- HTS high throughput screening -- APs alanwood pesticides, EUC, EU-cosmetics -- INCI international nomenclature of cosmetics ingredients -- EUFFA EU food flavoring agents -- EUFCM EU food contact materials -- ICs industrial chemicals -- SA Sigma-Aldrich -- DB drug bank -- CAS chemical abstracts service -- MOE molecular operating environment -- DMSO dimethyl sulfoxide -- DMEM Dulbecco's Modified Eagle's Medium -- FBS fetal bovine serum -- HPLC high performance liquid chromatography -- IC50 half maximal inhibitory concentration -- G6P glucose-6-phosphate -- 2D two dimensional -- sd structure data -- RMSD root mean square deviation -- PDB protein data bank -- VS virtual screening -- EtOH ethyl alcohol; Steroidogenesis -- Pharmacophore modeling -- Virtual screening -- Endocrine disruption -- Fungicide -- Environmental chemical -- Cortisol synthase -- Aldosterone synthase; Steroid hormones -- Periodicals; Biochemistry -- Periodicals; Hormones -- Periodicals; Molecular Biology -- Periodicals; Hormones stéroïdes -- Périodiques; Steroid hormones; Periodicals; 572.579
• DOI: 10.1016/j.jsbmb.2019.04.007
• Languages: English
• ISSNs: 0960-0760

Abstract

Highlights: CYP11B1 and CYP11B2 inhibitor pharmacophore models were used for the virtual screening of environmental chemical databases. Four out of 25 tested hits showed activity in hamster V79MZh cells expressing human CYP11B1 and CYP11B2. The most active hit, the fungicide epoxconazole, inhibited CYP11B1 and CYP11B2 with IC50 values of 623 nM and 113 nM, respectively. Epoxiconazole was also tested in H295R cells for steroid inhibition, which confirmed its activity. Abstract: Humans are constantly exposed to a multitude of environmental chemicals that may disturb endocrine functions. It is crucial to identify such chemicals and uncover their mode-of-action to avoid adverse health effects. 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) catalyze the formation of cortisol and aldosterone, respectively, in the adrenal cortex. Disruption of their synthesis by exogenous chemicals can contribute to cardio-metabolic diseases, chronic kidney disease, osteoporosis, and immune-related disorders. This study applied in silico screening and in vitro evaluation for the discovery of xenobiotics inhibiting CYP11B1 and CYP11B2. Several databases comprising environmentally relevant pollutants, chemicals in body care products, food additives and drugs were virtually screened using CYP11B1 and CYP11B2 pharmacophore models. A first round of biological testing used hamster cells overexpressing human CYP11B1 or CYP11B2 to analyze 25 selected virtual hits. Three compounds inhibited CYP11B1 and CYP11B2 with IC50 values below 3 μM. The most potent inhibitor was epoxiconazole (IC50 value of 623 nM for CYP11B1 and 113 nM for CYP11B2, respectively); flurprimidol and ancymidol were moderate inhibitors. In a second round, these three compounds were tested in human adrenal H295R cells endogenously expressing CYP11B1 and CYP11B2, confirming the potent inhibition by epoxiconazole and the more moderate effects by flurprimidol and ancymidol. Thus, the in silico screening, prioritization of chemicals for initial biological tests and use of H295R cells to provide initial mechanistic information is a promising strategy to identify potential endocrine disruptors inhibiting corticosteroid synthesis. A critical assessment of human exposure levels and in vivo evaluation of potential corticosteroid disrupting effects by epoxiconazole is required.