Skin lightening effect of the dietary intake of citrus peel extract against UV-induced pigmentation

Abstract

Recent studies revealed that citrus peel has beneficial effects in various disorders associated with nitric oxide and/or oxidative stress. In this study, we investigated the effects of Jeju citrus (Citrus unshiu) peel using various in vitro and in vivo methods. First, the inhibitory effect of citrus peel extract (CPE) on enzymatic activity of tyrosinase was evaluated. Tyrosinase activity was dose-dependently decreased by CPE. Second, the effect of CPE on melanogenesis was determined by measuring the melanin content in melan-a cells. The inhibitory effect of CPE on melanin synthesis was greater than that of vitamin C. Finally, the effect of long-term supplementation with CPE on ultraviolet B-induced skin pigmentation was examined in Guinea pigs. Administration of CPE improved ΔL-value compared with the nontreated ultraviolet control group. As a strong inhibitor of melanogenesis, CPE could be used as a depigmentation agent and a supplement for skin lightening.