Curcumin mediated apoptosis in AK-5 tumor cells involves the production ofreactive oxygen intermediates

Curcumin, the active ingredient of the rhizome of Curcuma longa has anti-in flammatory, antioxidant and antiproliferative activities. Although its prec ise mode of action remains elusive, studies have shown that chemopreventive action of curcumin might be due to its ability to induce apoptosis in canc er cells, Curcumin was shown to be responsible for the inhibition of AK-5 t umor (a rat histiocytoma) growth by inducing apoptosis in AK-5 tumor cells via caspase activation, This study was designed to investigate the mechanis m leading to the induction of apoptosis in AK-5 tumor cells, Curcumin treat ment resulted in the hyperproduction of reactive oxygen species (ROS), loss of mitochondrial membrane potential (Delta Psi(m)) and cytochrome c releas e to the cytosol, with the concomitant exposure of phosphatidylserine (PS) residues on the cell surface. This study suggests redox signalling and casp ase activation as the mechanisms responsible for the induction of curcumin mediated apoptosis in AK-5 tumor cells, (C) 1999 Federation of European Bio chemical Societies.