Discovery of A Novel Cyclopeptide as Tyrosinase Inhibitor for Skin Lightening

Melanin content significantly influences the skin-lightening effects of active ingredients, with inhibition of melanin synthesis contributing to skin-lightening effects. This study evaluates the effects of novel cyclopeptide CHP-9 as a safe and potent human tyrosinase inhibitor. CHP-9 showed a significant inhibition rate of approximately 28.57% at 1% concentration. The melanin formation assay, upon exposure to CHP-9 alone, resulted in a reduction of cellular melanin content from 30.90±1.13 μg/mL to 23.51±1.14 μg/mL. Additionally, in silico molecular docking experiments were conducted to verify the tyrosinase inhibitory activity of the cyclopeptide CHP-9 on tyrosinase and it was observed that hydrogen bonding is pivotal in the binding affinity of CHP-9 with the target enzyme in docking. These results suggest that the cyclopeptide CHP-9 may serve as a valuable bioactive compound for skin-lightening agents in cosmetics applications, specifically in reducing melanin production.