Isorhamnetin-3-O-neohesperidoside: A Novel Natural Dual Inhibitor of Tyrosinase and MC1R for Skin Pigmentation Management

Skin pigmentation is a common aesthetic issue that involves multiple biological processes in its regulation, with tyrosinase (TYR) and melanocortin 1 receptor (MC1R) playing pivotal roles. TYR is a key enzyme in melanin synthesis, while MC1R is involved in regulating the function of melanocytes and pigmentation. We aspire to develop a naturally sourced ingredient for skin pigment management. This study aims to develop a novel natural ingredient for skin pigment management. Our preliminary findings highlighted the superior TYR and MC1R inhibitory activity of isorhamnetin-3-O-neohesperidoside compared to arbutin, making it the focus of subsequent research endeavors. To screen for natural source inhibitors of TYR and MC1R. We conducted an initial screening using molecular docking methods, followed by in vitro cellular experiments to validate the docking results. We employed the dopachrome oxidation assay, Enzyme-Linked Immunosorbent Assay(ELISA), NaOH extraction and immunofluorescence staining to investigate the effects of isorhamnetin-3-O-neohesperidoside on TYR activity, MC1R expression, melanin content, and autophagy-related microtubule-associated protein 1 light chain 3 (MAP1LC3, LC3-II) expression. The results showed that isorhamnetin-3-O-neohesperidoside inhibited TYR activity, decreased MC1R expression and melanin content, and increased LC3-II expression. Based on these findings, we preliminarily conclude that isorhamnetin-3-O-neohesperidoside, identified through molecular docking, represents a promising natural candidate for skin lightening by reducing pigmentation.