Provided are indole alkaloid compounds of formula I, for example, pubescine, and the use of such compounds and compositions thereof to promote (e.g., enhance) melanogenesis and pigmentation.Also provided are plant extracts containing a compound of formula I, for example, pubescine, and the use of such a plant extract to promote (e.g., enhance) melanogenesis and pigmentation. The compound or plant extract may be prepared as pharmaceutical and cosmetic compositions, and may be used for the prevention and treatment of conditions that are related to aberrant melanogenesis activity.
