Inhibition of Human 20S Proteasome by Compounds from Seeds of Psoralea corylifolia

The 26S pro-teasome is composed of 20S core and 19S regulator. Since pro-teasomes interact primarily with endogenous proteins, inhi-bition of the proteolytic action of the proteasome may block the signaling action of the transcription factor NF- κB and, thus, inhibit the completion of the cell cycle and hence the mitotic proliferation of cancerous cells, leading to cell death by apopto-sis and inhibition of angiogenesis and metastasis.