Emodin Studies on Anti-inflammatory and Skin Barrier Improvement Activities

It has been reported that emodin, a major pharmacologically active ingredient of herbal medicines such as Polygonum cuspidatum, Polygonum multiflorum, Rheum palmatum, and Aloe vera, is effective in antioxidant, antibacterial, anti-inflammatory, anticancer, and liver protection. In this study, to investigate the potential of emodin to be used as a skin disease and functional material, the activity related to the improvement of inflammation and skin barrier function was confirmed. To observe the anti-inflammatory effect on HaCaT cells, which are human keratinocytes, cytokine inhibition was confirmed by ELISA kit and protein expression by western blot. In HaCaT cells activated with TNF-α (10 ng/mL)/IFN-γ (10 ng/mL), emodin was treated with each concentration (5, 10, 20, 40) µM. As a result, It was confirmed that the production amount of TNF-α, IL-1β and IL-6 decreased as the concentration of emodin increased. In the experimental results on the expression levels of inflammation-related proteins iNOS and COX-2, it was confirmed that 48% of iNOS and 29% of COX-2 were inhibited compared to control at a concentration of 20 µM of emodin. As an indicator of skin barrier function improvement, the mRNA expression level of filaggrin, involucrin, and loricirn and the production amount of filaggrin, involucrin, and loricirn were confirmed. and excellent results were obtained with an emodin concentration-dependent increase. In particular, filaggrin, which was produced twice as much as the control at a concentration of 20 µM, is a protein involved in the formation of NMF, a natural moisturizing factor, and is known to play an important role in moisturizing the stratum corneum. In conclusion, it was confirmed that emodin can be used as a material for improving inflammation and improving skin barrier function, which is part of the potential for use as a skin disease and functional material. It is believed that if additional research is performed in the future, the scope of its application can be further expanded.

Emodin의 항염 및 피부장벽개선 활성 연구

호장근, 적하수오, 대황, 알로에 등과 같은 생약재의 주요 약리 활성 성분인 emodin은 항산화, 항균, 항염, 항암, 간보호 등에 효능이 있는 것으로 보고되었다. 본 연구에서는 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성을 알아보기 위해 염증 개선과 피부장벽기능 개선 관련 활성을 확인하였다. human keratinocyte인 HaCaT 세포에 대하여 항염효과를 관찰하기 위해 cytokine억제능은 ELISA kit로, 단백질 발현은 western blot으로 확인하였다. TNF-α (10 ng/mL)/IFN-γ (10 ng/mL)로 활성화된 HaCaT 세포에서 emodin을 농도별(5, 10, 20, 40) µM로 처리한 결과 TNF-α, IL-1β 및 IL-6의 생성량은 emodin의 농도가 증가함에 따라 감소됨을 확인하였다. 염증관련 단백질인 iNOS, COX-2 발현량에 대한 실험결과에서도 emodin 20 µM 농도에서 control 대비 iNOS는 48%, COX-2는 29%가 저해됨을 확인하였다. 피부장벽기능 개선의 지표로써 filaggrin, involucrin, loricirn의 mRNA 발현 정도와 filaggrin, involucrin, loricirn의 생성량을 확인한 결과 에모딘 농도에 의존적으로 증가하는 우수한 결과가 얻어졌다. 특히 20 µM 농도에서 대조군 대비 2배의 생성량 증가를 보인 filaggrin은 천연보습인자인 NMF의 형성에 관계되는 단백질로 각질층의 보습에 중요한 역할을 하는 것으로 알려져 있다. 결론적으로 emodin의 피부 질환 및 기능성 소재로서의 활용 가능성 중 염증 개선 및 피부장벽기능 개선 소재로 활용될 수 있음을 확인하였으며 향후 추가적인 연구가 수행되면 그 활용 범위가 더 넓어질 수 있을 것으로 사료된다.