NCIt definition : A small-molecule organic arsenical with potential antineoplastic activity. Although
the exact mechanism of action is unclear, darinaparsin, a highly toxic metabolic intermediate
of inorganic arsenicals (iAs) that occurs in vivo, appears to generate volatile cytotoxic
arsenic compounds when glutathione (GSH) concentrations are low. The arsenic compounds
generated from darinaparsin disrupt mitochondrial bioenergetics, producing reactive
oxygen species (ROS) and inducing ROS-mediated tumor cell apoptosis; in addition,
this agent or its byproducts may initiate cell death by interrupting the G2/M phase
of the cell cycle and may exhibit antiangiogenic effects. Compared to inorganic arsenic
compounds such as arsenic trioxide (As2O3), darinaparsin appears to exhibit a wide
therapeutic window.;