Delphinidin chloride, a natural plant pigment found in berries and red wine, is a precursor of certain anthocyanins. Delphinidin chloride induces the release of nitric oxide from the vascular endothelium, resulting in vascular relaxation. At the dose of 1-40 µM, epithelial growth factor receptor signaling and estrogen receptor alpha expression were inhibited, which was associated with apoptosis and autophagy. Delphinidin chloride regulates JAK/STAT3 and MAPKinase signaling. Delphinidin also inhibited the histone acetyltransferase activity of p300/CBP (IC50 was about 30 µM).