A Study on the Whitening and Anti-Wrinkle Effects of Red Sword Bean Extract in Functional Cosmetics for Skin Care

In this study, to analyze and determine the bioactive compounds of red sword bean as natural ingredients for functional cosmetics, hot water extraction was performed with ethanol contents of 20%, 50%, and 80%. In addition, for the respective extracts, a gas chromatography-mass spectrometry (GC-MS) analysis for the determination of bioactive compounds and liquid chromatography-mass spectrometry (LC-MS) analysis for the determination of polyphenol and flavonoid contents were performed along with the determination of antioxidant capacity. Moreover, experiments were performed to test the skin whitening and anti-wrinkle effects; a cytotoxicity evaluation was also conducted. As a result of the colorimetric assay, the lightness (L) value decreased with increasing ethanol content, whereas the redness (a*) and yellowness (b*) values tended to increase. This is presumed to be because the active compounds of the double bond structure increased as the ethanol content increased. As a result of GC-MS analysis to determine chemical composition, the detection of ethyl gallate, an antioxidant, and mandelic acid, an active compound with whitening and wrinkle improvement effects, was confirmed; the detected concentrations increased with increasing ethanol content. In the experiment to examine the antioxidant effect of red sword bean extract, the IC50 value of the 80% ethanol extract showed a high antioxidant capacity comparable to that of the control, ascorbic acid. As a result of the tyrosinase inhibitory activity assay, the highest inhibition (%) was confirmed at 80% ethanol content. Furthermore, in the collagenase inhibitory activity assay, all extracts showed high collagenase inhibitory activity of over 90%. Specifically, at 20% ethanol content, a higher inhibition (%) was confirmed than that of the control, ascorbic acid.