Figure 3.

AR signaling pathway and the possible effect of soy isoflavones. Several possible mechanisms have been proposed to explain the mechanism by which isoflavone activity affects AR. Possible mechanism include the transcriptional regulation of AR, the induction of AR degradation by the proteasomal pathway and the inhibition of ligand-AR complex translocation to the nucleus, leading to the possible inhibition of nuclear AR binding to ARE and thereby triggering an effect on the transcription of androgen-dependent genes (e.g., PSA). Indirect effects of isoflavones on AR may also be mediated by affecting the synthesis of testosterone, its conversion to DHT and the sequestration of DHT from binding AR, thereby reducing prostate cancer risk. ↑ indicates induction; ⊥ indicates inhibition. AR, androgen receptor; ARE, androgen response element; DHT, dihydrotestosterone; Hsp90, heat-shock protein 90; PSA, prostatic-specific antigen; ub, ubiquitin; T, testosterone.