Peonidin chloride is a preparation of Peonidin, a methoxy anthocyanidin compound that exhibits antiinflammatory effects. Peonidin is described to inhibit 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced COX-2 expression, to decrease TPA-induced neoplastic transformation, and to block TPA-induced phosphorylation of extracellular signal-regulated kinases in JB6 P(+) cells.