Melanogenesis can be controlled by tyrosinase inhibition or by blocking the maturation processes of tyrosinase and its related proteins. Mangostenone F was isolated from the seedcases of
Garcinia mangostana. Mangostenone F was shown to be inactive against tyrosinase (IC
50 > 200 渭M) but was a potent 伪-glucosidase inhibitor in vitro (IC
50 = 21.0 渭M). Mangostenone F was found to inhibit production of melanin in the mouse melanoma cell line B16F10. Importantly, unlike most glycosidase inhibitors, mangostenone F displayed very low cytotoxicity (EC
50 > 200 渭M). The Western blot for expression levels of proteins involved in melanogenesis showed that mangostenone F down-regulated tyrosinase and TRP-2 expression. Treating B16F10 cells with mangostenone F significantly increased the susceptibility of tyrosinase to endoglycosidase H digestion, indicating that tyrosinase was unable to mature fully and pass to the
trans-golgi apparatus. Consistent with these data, in lysate assays, mangostenone F was shown to be a better inhibitor of 伪-glucosidases than deoxyno
jirimycin, a representative glycosidase inhibitor.
Keywords:
mangostenone F; 伪-glucosidase; endo H; cytotoxicity; melanogenesis