Phloretin is the aglucone of phlorizin, a plant-derived dihydrochalcone phytochemical reported to promote potent antioxidative activities in peroxynitrite scavenging and the inhibition of lipid peroxidation. Phloretin, which is present in apples, pears, and tomatoes, has been found to inhibit the growth of several cancer cells and induce apoptosis of B16 melanoma and HL60 human leukemia cells. Phloretin also inhibits HT-29 cell growth by inducing apoptosis, which may be mediated through changes in mitochondrial membrane permeability and activation of the caspase pathways. Phloretin is a biomarker for the consumption of apples. As for topical application to the skin, phloretin neutralizes damaging free radicals, helps improve cell turnover, and improves the appearance of discoloration.