Skin-Lightening Effect of a Polyphenol Extract from Acerola (Malpighia emarginata DC.) Fruit on UV-Induced Pigmentation

To investigate the physiological functions of polyphenols from acerola (Malpighia emarginata DC.) fruit, the effects on melanogenesis were studied. The crude polyphenol concentrated extract from acerola (GAP) was used to examine the skin-lightening effect on brownish guinea pigs which had been subjected to controlled UVB irradiation. The results show that GAP significantly lightened the UVB-irradiated skin pigmentation. Furthermore, treatment with GAP reduced the content of melanin in B16 melanoma cells, suggesting that the in vivo skin-lightening effect of GAP was due to the suppression of melanin biosynthesis in melanocytes. In addition, we found that GAP could effectively inhibit mushroom tyrosinase activity, the main constituents responsible for this effect being thought to be such anthocyanins as cyanidin-3-alpha-O-rhamnoside (C3R) and pelargonidin-3-alpha-O-rhamnoside (P3R). This result indicates that the skin-lightening effect of GAP can he partly attributed to the suppression of melanogenesis through the inhibition of tyrosinase activity in melanocytes. An oral ingestion of GAP may therefore be efficacious for reducing UVB-induced hyper-pigmentation by inhibiting the tyrosinase in melanocytes.