Breeding Dry Beans (Phaseolus vulgaris L.) for Cancer Inhibitory Activity: A New Facet in Contemporary Crop Improvement.

Dry edible beans (Phaseolus vulgaris L.)are distinguished by seed characteristics  that classify them into distinct market classes such as navy bean and white kidney bean.  Based on our evaluation of ten dry bean market classes, we found dry beans, incorporated into a purified rodent diet in a form eaten by humans, inhibited experimentally-induced breast cancer by as much as 70%, an effect that could not be accounted for by  isoflavone content (which is low), by total phenolic content , or by seed coat pigment.  Moreover, marked variation in cancer preventive activity was associated with the geographic origin (referred to as Center of Domestication, COD) of the dry bean market classes. The fact that the cancer inhibitory activity of dry beans differed based on COD has been used to facilitate efforts to elucidate the mechanisms that account for this protective activity. This presentation will review ongoing efforts to: 1) identify the cellular basis for cancer preventive activity of dry beans against mammary carcinogenesis,  2) investigate the cell signaling pathway(s) modulated by dry beans that could account for their cancer preventive activity, and 3) elucidate the classes of chemicals that account for cancer inhibitory activity of dry beans and for the differences observed between dry beans from different COD.  Our goal is determine what chemicals account for dry bean effects on cellular/molecular mechanisms that inhibit carcinogenesis and whether the difference between COD is due to the presence of the same chemicals in different amounts or to different chemicals in dry beans from each COD.