한방 화장품 원료에 있어 추출물 내 타닌의 수렴효능에 관한 연구

Astringency of Tannins in Traditional Herb Extracts

&nbsp;&nbsp;Most of natural plant, which generally contains various tannins, gives astringent effect to human skin. That astringency could be precisely measured by red blood cell test, a complex forming reaction between animal blood and tannins. That complex produced is not water-soluble and the amount of complex is proportional to the astringency of each plant extract. This means that proportional to the amount of complex produced, the color of blood becomes pale. Therefore, the astringency can be measured instrumentally by observing the decrease of absorbance value at 576nm where characteristic peak of blood exists through UV-vis Spectrophotometer.<BR>&nbsp;&nbsp;Critical Astringency Concentration was defined as a concentration of natural plant extract required to reduce absorbance value of blood to 50% and then Relative Astringency of a natural plant extract can be calculated by dividing critical astringency concentration of each natural plant extract with that of tannic acid. RA is a useful scale to compare astringency of every extract.<BR>&nbsp;&nbsp;Plant selected here such as Gallo Rhois, Areca, Rheum, Eugenia and Uncaria are famous for their astringency historically. When each plant was extracted in 10% ethanol in water, high yield of tannins and lower content of sugar moiety was experimentally obtained.<BR>&nbsp;&nbsp;Critical Astringency Concentration of each extract was measured as follows, 6.8mg/ml for Gallo Rhois, 17.7mg/ml for Areca, 27.8mg/ml for Rheum, 31.4mg/ml for Eugenia and 70.0 mg/ml for Uncaria.<BR>&nbsp;&nbsp;And RA of Gallo Rhois was 1.45, 0.55 for Areca, 0.35 for Rheum, 0.31 for Eugenia and 0.14 for Uncaria. That result shows that astringency of Gallo Rhois is 10 times higher than that of Uncaria.<BR>&nbsp;&nbsp;As a reproducible and precise scale for measuring astringency effect, this method could replace the sensory method, which have been customarily carried out in Cosmetic industry at any time.