Abstract
To obtain effective and safe depigmenting agents, we investigated the effects of Scirpi rhizoma, a medicine among Chinese herbs, on melanogenesis. Dried S. rhizoma was refluxed with 70% aqueous ethanol and the extract was evaporated to dryness. To determine the effects as a whitening agent, various in vitro tests were performed such as free radical scavenging activity, melanin formation assay, tyrosinase activity and expression of tyrosinase, TRP-1 and TRP-2(western blot and RT-PCR) in B16 melanoma cells. S. rhizoma showed scavenging activities of free radicals and reactive oxygen species (ROS) with the $IC_{50}\;of\;638{\mu}g/mL$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and $21.7{\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. S. rhizoma significantly inhibited melanin production in B16 melanoma cells. S. rhizoma treatment(48 h) suppressed the biosynthesis of melanin up to 27% at 100{\mu}g/mL$ and reduced tyrosinase activity up to 31% at $100{\mu}g/mL$ in B16 melanoma cells. S. rhizoma was also able to significantly inhibit tyrosinase and TRP-1 expression in protein and mRNA level. These results suggest that S. rhizoma inhibited melanin biosynthesis by regulating tyrosinase activity and expression in B16 melanoma cells. Therefore, S. rhizoma may be useful as a new antioxidant and whitening agent to inhibit melanogenesis.
본 연구에서는 한방 천연 미백 소제를 개발하기 위하여 삼릉추출물의 미백 효과에 대하여 연구하였다. 삼릉추출물은 프리 라디칼 소거활성(DPPH)에서 $IC_{50}=638{\mu}g/mL$, superoxide radicals 소거활성은 $IC_{50}=21.7{\mu}g/mL$을 나타냈다. 삼릉추출물의 B16 melanoma 세포에서의 멜라닌 생합성 저해효과는 $100{\mu}g/mL 삼릉추출물을 48 h 처리한 세포에서는 멜라닌 합성량이 27% 감소되었다. 삼릉 추출물은 농도에 비례하여 B16 melanoma 세포내의 타이로시네이즈 활성을 저해하였으며, western blot을 이용하여 타이로시네이즈와 타이로시나아제 관련 단백질(TRP-1)의 발현감소를 확인하였다. 또한, RT-PCR을 이용하여 삼릉추출물이 멜라닌 생성 과정에 관련하는 유전자 발현을 조사한 결과 타이로시네이즈와 TRP-1의 mRNA발현을 억제하는 것을 확인하였다. 그러므로 삼릉추풀물은 항산화 효과와 함께 멜라닌 저해 효과가 우수하여 새로운 미백 화장품으로 응용할 수 있을 것으로 생각된다.
