구기자, 건조구기엽, 생구기엽 추출물의 미백효과를 검증하였다. Tyrosinase 저해활성 측정결과 건조구기엽 에탄올추출물 $500{mu}g/mL$에서 44%의 저해활성을 나타내었으며, melanoma cell (B16F10)에서의 melanin 생합성 저해율 측정결과 건조구기 엽 에탄올 추출물 $50{mu}g/mL$에서 14%의 저해효과를 나타내었다. 구기자, 건조구기엽, 생구기엽 추출물을 처리한 B16F10군에서는 tyrosinase protein의 발현이 처리하지 않은 군보다 감소하였다. 특히, 건조구기엽 추출물의 경우 tyrosinase의 단백질 발현량을 많이 저해하였다. 결과적으로 건조구기엽 추출물의 미백활성이 가장 우수하였으며, 식품 및 화장품의 기능성 소재로 이용이 가능할 것으로 판단된다.
The objective of the present study was to evaluate the skin whitening effect of the extracts, Lycii fructus (LF), Dry-L. foilum (DLF) and Fresh-L. folium (FLF). Tyrosinase inhibition activities was 44% in DLF ethanol extracts at a $500{mu}g/mL$. When the tyrosinase activities in B16F10 murine melanoma cell were tested, the activities in DLF ethanol extracts was 14% at a $50{mu}g/mL$ concentration. The protein expression of microphthalmia-associated transcription factor, tyrosinase related protein 1 (TRP-1), TRP-2, and tyrosinase, which are all melanin related factors, showed that LF, DLF and FLF extracts inhibited the protein bio-synthesis in B16F10 melanoma cell. Especially the DLF extract showed greater decrease of protein expressions. Results indicate that the DLF extract tested in the present study had skin whitening activity and can be used as a function a ingredients for food and cosmetic compositions.
