Bakuchiol exhibits anti-metastasis activity through NF-κB cross-talk signaling with AR and ERβ in androgen-independent prostate cancer cells PC-3.

Androgen-independent prostate cancer (PCa) is a developed tumor derived from the local androgen dependent PCa, which often affects elderly men. Psoralea corylifolia L, a traditional Chinese medicine, has been widely used for PCa treatment as an important part of a common prescription, while the mechanism remains unclear. Our study was aimed to investigate the tumor-inhibitory effect of its main component bakuchiol in androgen-independent PCa cell line PC-3 cells. Bakuchiol significantly suppressed PC-3 cell proliferation and migration; the expressions of PCNA and MMP-9 were consistently down regulated as well. Meanwhile, both the constitutive and LPS-induced NF-κB activation were significantly inhibited by bakuchiol. The inhibitory effects of bakuchiol on cell proliferation, migration and invasion were recovered when LPS were added together with bakuchiol. SiRNA against androgen receptor (AR) or estrogen receptor β (ERβ) were transfected and the regulation of bakuchiol-suppressed proliferation, invasion, NF-κB signaling and MMP-9 secretion in response to LPS were blocked. Taken together, our data demonstrated that bakuchiol inactivated NF-κB signaling via AR and ERβ, which contributes to inhibition of PC-3 cell proliferation and migration, indicating that bakuchiol is one of the key component from P. corylifolia L for PCa treatment and has a potential as anti-prostate cancer drug candidates.