Delphinidin (chloride) is an anthocyanidin, a natural plant pigment which serves as the precursor of certain anthocyanins that provide the blue-red colors of flowers, fruits, and red wine. Delphinidin induces the release of nitric oxide by vascular endothelium, causing vasorelaxation. It also inhibits signaling through epithelial growth factor receptors, suppressing the expression of estrogen receptor α and inducing both apoptosis and autophagy at a dose of 1-40 μM. Delphinidin also inhibits the histone acetyltransferase activities of p300/CBP (IC50 = ~ 30 μM).