抄録
Mannosylerythritol lipids (MELs) are biosurfactants known for their versatile interfacial and biochemical properties. To broaden their application in cosmetics, we investigated the antioxidant properties of different MEL derivatives (MEL-A, -B, and -C) by using a 1,1-diphenyl-2-picryl hydrazine (DPPH) free-radical- and superoxide anion-scavenging assay. All MEL derivatives tested showed antioxidant activity in vitro, but at lower levels than those of arbutin. Of the MELs, MEL-C, which is produced from soybean oil by Pseudozyma hubeiensis, showed the highest rates of DPPH radical scavenging (50.3% at 10 mg/mL) and superoxide anion scavenging (>50% at 1 mg/mL). The antioxidant property of MEL-C was further examined using cultured human skin fibroblasts (NB1RGB cells) under H2O2-induced oxidative stress. Surprisingly, MEL-C had a higher protective activity against oxidative stress than arbutin did: 10 μg/mL of MEL-C and arbutin had protective activities of 30.3% and 13%, respectively. Expression of an oxidative stress marker, cyclooxygenase-2, in these cells was repressed by treatment with MEL-C as well as by arbutin. MEL-C was thus confirmed to have antioxidant and protective effects in cells, and we suggest that MELs have potential as anti-aging skin care ingredients.
