Anti-oxidant and Whitening Effect of Low Molecular Weight Kaki-tannin with Gamma irradiation

Abstract

Purpose: This study aimed to investigate the use of purified Kaki-tannin obtained from a Korean natural product, Diospyros kaki Thumb. In order to confirm the potential application of kaki-tannin to cosmetics, the efficacy was evaluated by kakit-annin that molecular weight decreased by gamma irradiation.Methods: Kaki-tannin polymer was extracted by hydrothermal extraction from persimmon. The molecular weight of Kaki-tannin polymer reduced by gamma-ray irradiation, and then separated and purified. Further, the molecular weight of this polymer was reduced by gamma-ray irradiation; subsequently, it was separated and purified. Radical scavenging activities of this reduced molecular weight Kaki-tannin were examined by the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) diammonium salt radical cation, and hydroxyl radical scavenging assays. Moreover, the inhibitory effects of Kaki-tannin on tyrosinase and melanin synthesis in B16F10 melanoma cells were measured in vitro. Furthermore, the expression of tyrosinase, microphthalmia-associated transcription factor (MITF), tyrosinase-related protein (TRP)-1, and TRP-2 during melanogenesis was confirmed by western blotting.Results: Irradiated Kaki-tannin exhibited an antioxidant effect as well as suppressed tyrosinase activity and melanogenesis. The results of this study confirmed that the expression of tyrosinase, MITF, and TRP-2 decreased as the treatment of irradiated Kaki-tannin increased.Conclusion: In the present study, to incorporate high molecular weight Kaki-tannin in cosmetics, it was first irradiated with gamma rays in order to reduce its weight. This study confirmed that Kaki-tannin irradiated by gamma-ray has antioxidant and whitening effects as well as the potential to be used as a cosmetic material.