Prevention of cancer and inflammation by soybean protease inhibitors

Several plant-based nutrients and non-nutrients that can inhibit mutagenesis and cell proliferation have been identified. Some of the most promising compounds identified as chemopreventive and anti-metastatic agents include soybean-derived protease inhibitors (PIs), Bowman-Birk Inhibitor (BBI) and Kunitz-Trypsin Inhibitor (KTI). A growing body of evidence suggests that BBI could act as anti-carcinogenic agent and KTI is considered to prevent cancer invasion and metastasis. These inhibitors are non-toxic, are of low cost and can be taken orally or as a part of the daily diet. PIs are undergoing investigation in the clinical setting as potential agents for chemoprevention and anti-metastasis. A complex scenario about the interaction between PIs and cell signaling has been emerging. Soybean PIs are not just anti-proteolytic proteins, but can also be modulators of cell signal transduction. Cancer and inflammatory treatment strategies modulating signal transduction need further investigation.