Selective Radioprotection of Normal Tissues by Bowman-Birk Proteinase Inhibitor (BBI) in Mice

Abstract

BBI acts as a potent selective normal-tissue radioprotector in vitro and in vivo, apparently without protecting tumors, and thus has the potential to improve clinical radiotherapy.

Bowman-Birk inhibitor concentrate prevents atrophy, weakness, and oxidative stress in soleus muscle of hindlimb-unloaded mice

“…BBI is a well-characterized soy protein (6) that has anticarcinogenic (41), chemoprotective (19), and radioprotective (10,15) effects via mechanisms of action that include serine protease inhibition (6) and antioxidant properties (14,15,39). In support of the latter mechanism, BBI has been shown to lessen production of reactive oxygen species by nonmuscle cell types (14,39) and to diminish the systemic oxidative stress caused by whole body irradiation (15).…”

Bowman-Birk Inhibitors from Legumes: Utilisation in Disease Prevention and Therapy

“…The radioprotective properties of BBI have been tested on cell cultures; so far, no data regarding efficacy in humans are available. Soybean BBI have shown potent and selective radioprotection of normal tissue in vitro [80] and in vivo [81], without protecting tumor tissue. Dittmann et al [81] showed that soybean BBI increased clonogenic survival after irradiation only in cells, either normal or transformed, having a wild-type p53 tumor suppressor gene.…”

“…Soybean BBI have shown potent and selective radioprotection of normal tissue in vitro [80] and in vivo [81], without protecting tumor tissue. Dittmann et al [81] showed that soybean BBI increased clonogenic survival after irradiation only in cells, either normal or transformed, having a wild-type p53 tumor suppressor gene. In a cell line with inducible expression of mutated p53, the radioprotective effect of BBI was only detected when the expression of the mutated p53 was switched off [75].…”

Contemporary Radiation Countermeasure

“…It was demonstrated that pretreatment of mice with BBI significantly decreased radiationinduced leg contracture 47 . Based on the previous experiments, it was determined that this inhibitor improved DNA repair of initial damage and thus enhanced genomic integrity and prevented radiation-induced terminal differentiation of fibroblasts 46 .…”