Apoptosis-independent alterations in membrane dynamics induced by curcumin

Curcumin is a well-known natural compound with antiinflammatory properties. Its antiproliferative effect and ability to modulate apoptotic response ar e considered essential in cancer therapy. The physicochemical properties of curcumin suggest membranous localization, which prompted an investigation of the mechanisms of membrane disturbances evoked by curcumin. We chose the erythrocyte as a convenient model for studying membrane effects of curcumi n and showed its nonspecific, apoptosis-independent way of action. Curcumin was found to expand the cell membrane, inducing echinocytosis. Changes in cell shape were accompanied by transient exposure of phosphatidylserine. Me mbrane asymmetry was recovered by the action of aminophospholipid transloca se, which remained active in the presence of curcumin. Lipids rearrangement s and drug partitioning caused changes of lipid fluidity, Such nonspecific effects of curcumin on cellular membranes would produce artifacts of apopto sis measurement, since several methods are based on membrane changes, (C) 1 998 Academic Press.