Cover Image

HARDBACK
$59.95



View/Hide Left Panel

Substance

Study Design

Results and Conclusions

 

 

but not androst-4-ene-3,17-dione (∆4-A) (Délos et al., 1995).

Extract of fruit (Permixon), 10 μg/mL

Cells in coculture: human prostate fibroblasts and epithelial cells

Addition of extract inhibited type I and type II steroid 5-α-reductase activity (Bayne et al., 1999).

Extract of fruit (Permixon)

Cells in culture: human prostatic carcinoma cell line (DU 145)

Addition of extract inhibited metabolism of [3H]-testosterone (0.1 μM, 1–6 h) by intact cells in culture (Délos et al., 1994).

Extract of fruit (Permixon)

Human steroid 5-αreductase, type 1 and 2 isoforms expressed in insect cells (fall armyworm, Spodoptera frugiperda Sf9) transfected with baculovirus DNA (Autographa californica nuclear polyhedrosis virus, AcNPV)

Addition of extract inhibited baculovirus DNA steroid 5-α-reductase activity in cell homogenates of transfected cells (using 5 mM NADPH; 1 μM [3H]-testosterone for IC50 assays; 0.1–10 μM [3H]-testosterone for Ki assays). Type 1 isoform: noncompetitive inhibition; IC50 = 4 μg/mL, Ki = 7–8 μg/mL (Délos et al., 1995; Iehlé et al., 1995). Type 2 isoform: uncompetitive inhibition; IC50 = 7 μg/mL, Ki = 5 μg/mL (Iehlé et al., 1995). For comparison, finasteride was found to be a competitive inhibitor of 5α-reductase type 1 (IC50 = 0.5 μM, Ki = 0.3 μM) and type 2 (IC50 = 11 ηM, Ki = 7 ηM).

Addition of extract inhibited activity of partially purified, expressed type 1 steroid 5-α-reductase (liposome entrapped to preserve activity of this nuclear membrane-associated enzyme) (Iehlé et al., 1995).



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement