Taxifolin Inhibits Neurosteroidogenic Rat Steroid 5α-Reductase 1 and 3α-Hydroxysteroid Dehydrogenase.
Pharmacology 2019;
105:397-404. [PMID:
31865316 DOI:
10.1159/000504057]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 10/09/2019] [Indexed: 11/19/2022]
Abstract
AIMS
Taxifolin, a flavonoid, has several pharmacological activities. Taxifolin inhibits some steroid biosynthetic enzymes, suggesting that it might inhibit neurosteroid synthesis. Here, we investigated effects of taxifolin on rat neurosteroidogenic enzymes, steroid 5α-reductase 1 -(SRD5A1), 3α-hydroxysteroid dehydrogenase (AKR1C9), and retinol dehydrogenase 2 (RDH2).
METHODS
SRD5A1, AKR1C9, and RDH2 were expressed in COS-1 cells and the direct effects of taxifolin on these enzymes and the mode of action were determined using steroid substrates and thin chromatography separation-coupled radiometric scanning.
RESULTS
The half maximal inhibitory concentration values of taxifolin on SRD5A1 and AKR1C9 were 100 and 1.01 mol/L. Taxifolin did not inhibit RDH2 even at as high as 100 mol/L. Taxifolin competitively inhibited rat AKR1C9 against steroid dihydrotestosterone (DHT), and docking analysis revealed that taxifolin bound to the steroid binding site of rat AKR1C9 with similar free energy with the substrate DHT.
CONCLUSION
Taxifolin is a potent inhibitor of rat AKR1C9 and moderate inhibitor of rat SRD5A1, thereby controlling the rate of neurosteroid biosynthesis.
Collapse