Screening of antioxidants and cosmeceuticals from natural plant resources in Jeju Island

Fifty-four natural plants from Jeju Island, Korea were extractesd by 70% methanol. The extracts containing the highest total phenolic contents (TPC) (>250mg gallic acid equivalents/g dry sample) were obtained from Ostrya japonica, Geranium thunbergeii, Malus siebildii, Ardisia japaoneca, and Agrumonia pilosa. DPPH inhobotion activity was greatest in Tyrosinase inhibition anhibition activities of more than 85% were obtained from the extracs of Persicaria filiformis, Rhus javanica, Alnus furma, and Myrica rubra. On the other hand, the P. filiformis and M. rubra extracts each showed more than 90% XOD inhibition activity. The five natural plants with the highest biological activities were also extracted by pressurized liquid (PLE, 100% methanol, 13.6 MPa, 40°C). The DPPH and turosinase activities were almost the same in both the 70% methanol and PLE extracts. The DPPH and tyrosinase inhibition activites were almost the same in both the 70% methanol and PLE extracts. The IC ₅₀ for tyrosinase and elastase inhibition activities in PLE wrer 802 and 88 ppm in A. Japonica, and 959 and 66 pm in M. rubra, respectively.