Cannabidiol-induced apoptosis in human leukemia cells: a novel role of cannabidiol

In the current study, we examined the effects of the nonpsy-choactive cannabinoid, cannabidiol, on the induction of apo-ptosis in leukemia cells. Exposure of leukemia cells to canna-bidiol led to cannabinoid receptor 2 (CB2)-mediated reduction in cell viability and induction in apoptosis. Furthermore, canna-bidiol treatment led to a significant decrease in tumor burden and an increase in apoptotic tumors in vivo. From a mechanistic standpoint, cannabidiol exposure resulted in activation of caspase-8, caspase-9, and caspase-3, cleavage of poly(ADP-ribose) polymerase, and a decrease in full-length Bid, suggest-ing possible cross-talk between the intrinsic and extrinsic apoptotic pathways. The role of the mitochondria was further suggested as exposure to cannabidiol led to loss of mitochon-drial membrane potential and release of cytochrome c. It i