b-Amyloid (bA) induced oxidative stress is a well-established pathway of neuronal cell death in Alzheimer's disease. From turmeric, Curcuma longa L. (Zingiberaceae), three curcuminoids, curcumin, demethoxycurcumin, and bisdemethoxycurcumin, were found to protect PC12 rat pheochromocytoma and normal human umbilical vein endothelial (HUVEC) cells from bA(1±42) insult, as measured by 3-[4,5-dimeth...