Modulation of oxidative stress and melanogenesis by proanthocyanidins

Proanthocyanidins (PAs) are polymer chains of flavonoids known to have a high free radical scavenging capacity. However, their efficacy for use in dermatological health has not been fully explored. In the present study, we investigated the inhibitory property of PAs on melanogenesis and oxidative stress of cultured B16F10 melanoma cells (B16 cells) utilizing both oligomer and polymer PAs that were isolated from freshly crushed persimmon peel. To assess the suppressive effects of PAs against oxidative insults, lipid peroxidation, total reactive species (RS), peroxynitrite (ONOO(-)), superoxide ( O(2)), and nitric oxide (NO ) were quantitated. In addition, the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio was measured to evaluate the cellular oxidative status. Results showed that the PAs studied had a strong inhibitory effect on the murine tyrosinase and melanin synthesis that was correlated with the modulation of oxidative stress. Thus, our present work produced evidence that in B16 cells, the anti-melanogenic capacity of PAs as shown by the inhibition of tyrosinase and melanin synthesis likely occurs through the suppression of oxidative stress by the ability of PAs to modulate total RS, O(2), NO , ONOO(-), lipid peroxidation, and redox balance.