The present disclosure discloses a novel use of genistein, epigallocatechin gallate (EGCG), derivatives thereof, isomers thereof, pharmaceutically acceptable salts thereof, prodrugs thereof, hydrates thereof and solvates thereof. A composition containing genistein, epigallocatechin gallate, derivatives thereof isomers thereof, pharmaceutically acceptable salts thereof, prodrugs thereof, hydrates thereof or solvates thereof reduces the expression of factors related to increase of melanin producing ability, reduces the expression of senescence marker proteins and regulates the expression of enzymes involved in melanin production, and thus may have an effect of rejuvenating cells including melanocytes.