Physiological Activity of Magnolia kobus A. P. DC. Leaf Extracts and Enhancement of Skin Permeation Using PCL-PEG Polymer Micelle and Cell Penetrating Peptide

목련 잎 추출물의 생리 활성 및 PCL-PEG 고분자 미셀과 세포투과 펩티드를 적용한 피부흡수증진 효과

In this study, we report the development of a cosmetic material from Magnolia kobus A. P. DC. leaves. Following an assessment of the anti-oxidant, anti-wrinkle, and whitening effects of the hydrothermal and ethanol extracts, total polyphenol contents were quantified as 39.68 mg/g and 60.95 mg/g respectively, while the DPPH radical scavenging activity (IC50 values) were 476.03 ㎍/mL and 161 ㎍/mL respectively, and the SOD-like activities were 79.80% and 97.75%, respectively at a concentration of 100 ㎍/mL. At a concentration of 1,000 ㎍/mL, the elastase inhibition activities of hydrothermal and ethanol extracts were 55.17% and 57.77% respectively, and at concentration of 4,000 ㎍/mL, the tyrosinase inhibition activities were 27.36% and 75.58%, respectively. To solve the problem of insolubility with ethanol extract, which is more physiologically active than hydrothermal extract, PCL-PEG polymeric micelle was used resulting in solubility of the ethanol extract and reductions in particle sizes of greater than one-tenth. In addition, to improve skin permeability, 0.1% cell-penetrating peptide R6 (hexa-D-arginine) was used; the cumulative permeated amounts of: i) 1.0% ethanol extract, ii) ethanol extract and distilled water (1:1 mixture solvent), and iii) PCL-PEG polymeric micelle containing 1.0% ethanol extract, were 58.07 ㎍/cm², 75.86 ㎍/cm², 95.59 ㎍/cm², respectively. In other words: i) various physiological activities were affected by ethanol extracts, ii) the ethanol extract was solubilized by PCL-PEG and, iii) skin absorption was increased following addition of the cell-penetrating peptide, R6. These results confirm the potential for Magnolia kobus A. P. DC. leaf ethanol extract to serve as a new, natural functional cosmetic material.