Diterpenes from Cryptomeria japonica inhibit androgen receptor transcriptional activity in prostate cancer cells.

We identified eight diterpenes from Cryptomeria japonica (Taxodiaceae), which inhibit the activity of the androgen receptor (AR) in human prostate cancer (PCa) 22Rv1-derived 103E cells. The compounds 6,12-dihydroxyabieta-5,8,11,13-tetraen-7-one ( 2), sugiol ( 3), ferruginol ( 4), and 5-epixanthoperol ( 7) have near 100 % AR inhibition efficacy at concentrations of 10, 5, 25, and 25 microM, respectively. Because these compounds have very similar structures, analysis of their differential activity may aid in the design of inhibitors for PCa treatment.