Glucopsychosine increases cytosolic calcium to induce calpain-mediated apoptosis of acute myeloid leukemia cells

To identify novel anti-cancer agents, we created and screened a unique nutraceutical library for activity against acute myeloid leukemia (AML) cells. From this screen, we determined that glucopsychosine was selectively toxic toward AML cell lines and primary AML patient samples with no effect toward normal hematopoietic cells. It delayed tumor growth and reduced tumor weights in mouse xenograft models without imparting toxicity. Glucopsychosine increased cytosolic calcium and induced apoptosis through calpain enzymes. Extracellular calcium was functionally important for glucopsychosine-induced AML cell death and surface calcium channel expression is altered in AML cells highlighting a unique mechanism of glucopsychosine's selectivity.