Citrulluside T, Isolated from the Citrullus lanatus Stem, Inhibits Melanogenesis in α-MSH-Induced Mouse B16F10 Cells

With the increasing number of cosmetic consumers emphasizing value consumption and sustainability, upcycling has gained attention as a solution to agricultural by-products, which are main culprits environmental problems. In this study, we isolated citrulluside T with whitening activity from discarded Citrullus lanatus stems investigated anti-melanogenic effect underlying mechanisms. We found that did not exhibit cytotoxicity up concentration 90 μM significantly reduced melanin content intracellular tyrosinase in B16F10 cells. addition, inhibited expression melanogenic enzymes such tyrosinase, tyrosinase-related protein (TRP)-1, TRP-2, well synthesis via cAMP-dependent kinase (PKA)/cAMP response element-binding (CREB)-mediated downregulation microphthalmia-associated transcription factor (MITF), key melanogenesis. Furthermore, exerted its by downregulating β-catenin upregulating phosphorylated β-catenin. Finally, confirmed was safe for skin through irritation tests on 33 subjects, suggesting applicability protective agent against hyperpigmentation topical applications cosmetics ointments.