A Study of the Whitening Activities of Magnolia obovata Bark Ethyl Acetate Fractions as Cosmetic Ingredient

Abstract

EtOAc fractions of Magnolia obovata (M. obovata) Bark extracts were studied for the potential ingredient as a safe and effective whitening cosmetic material. The concentration of active substances honokiol was determined by HPLC. In vitro, the fractions reduced the extracellular and intracellular melanin contents in B16F10 cells in dose dependently and inhibited extracellular melanin secretion (IC50 = 11.05 μg/mL). The 12.5 μg/mL treatment of maximum concentration effectively inhibited up to about 60% to the amount of extracullular melanin. Also, the 12.5 μg/mL treatment of maximum concentration effectively inhibited up to about 59% to the amount of intracullular melanin (IC50 = 10.85 μg/mL). The IC50 value of α-arbutin used as a positive control was 59.99 μg/mL. So, EtOAc fractions of M. obovata Bark extracts showed whitening effect when compared with the non-treatment group. In case of in vivo study, Cosmetic cream with EtOAc fractions of M. obovata Bark extracts was approved by Ethics committee of KDRI (IRB number: KDRI-IRB-1537). As a result in progress for skin sensitization as well as assessment of skin irritation through repeated patch test, skin allergens was identified as non sensitizing agents. Also, cosmetic cream with EtOAc fractions of M. obovata Bark extracts showed significant topical whitening effect and reliable skin safety when compared with the non-treatment group. In conclusion, EtOAc fractions of M. obovata Bark extracts may be a useful cosmetic ingredient for effective skin whitening.