Natural product extracts of the Canadian prairie plant, Thermopsis rhombifolia, have anti-cancer activity in phenotypic cell-based assays.

Many plant species within the terrestrial ecological zones of Canada have not yet been investigated for anti-cancer activity. We examined the scientific literature describing the endemic flora from the prairie ecological zone and selected the species, Thermopsis rhombifolia, locally known as the buffalo bean, for investigation of its anti-cancer potential. We tested it in cell-based assays using phenotypic screens that feature some of the hallmarks of cancer. An ethanolic extract prepared from T. rhombifolia was cytotoxic to HT-29 (colon) and SH-SY5Y (brain) cancer cell lines, and showed little cytotoxicity to a normal human cell line (WI-38). In phenotypic assays, we identified activities in the extracts that target cell death, cell cycle and cell adhesion. These data highlight the anti-cancer potential of previously untested plants found in northern ecological zones and the feasibility of using pertinent phenotypic assays to examine the anti-cancer potential of natural product extracts.