J. Cosmet. Sci., 62, 505–514 (September/October 2011) 505 Clinical effi cacy of facial masks containing yoghurt and Opuntia humifusa Raf. (F-YOP) GYOSEON YEOM, DAE-MYOUNG YUN, YUN-WON KANG, JI-SOOK KWON, IN-OH KANG, and SUN YEOU KIM, Skin Science Laboratory, R&D Center, iPEERES Cosmetics Ltd. (G.Y., D.-M.Y., J.-S.K.), Skin Care Laboratory, R&D Center, iPEERES Cosmetics Ltd., Anseong-si, Gyeonggi-do, 456-843 (Y.-W.K., I.-O.K.), and Department of Medical Science, Graduate School of East-West Medical Science, Kyung Hee University Global Campus, Giheung-Gu, Gyeonggi- Do, 446-701 (G.Y., S.Y.K), Republic of Korea. Accepted for publication March 28, 2011. Synopsis Facial packs or masks are popular beauty treatments that are thought to improve skin quality. We formulated a yoghurt pack using natural ingredients (F-YOP), with consideration of skin affi nity, safety, health, and beauty. Then, we performed an in vitro assessment of biological activity and in vivo assessments of moisture, TEWL, melanin content, and elasticity. Facial areas treated with F-YOP showed increased moisture com- pared to control regions: 89±6.26% (forehead), 140.72±10.19% (cheek), and 123.29±6.67% (chin). Tran- sepidermal water loss (TEWL) values were decreased in the treated areas compared to control: 101.38±6.95% (forehead), 50.37±5.93% (cheek), and l57.81±10.88% (chin). Elasticity was decreased in the control region, whereas the treatment region did not change. The initial elasticity was maintained in the cheek. F-YOP ex- hibited activity on DPPH radical scavenging, SOD-like activity, and lipoxygenase activity. F-YOP treatment successfully improved the moisture, brightness, and elasticity of treated skin. INTRODUCTION Recently, the market for natural cosmetic products has grown to meet the demands of individuals who are concerned about health and beauty, and it continues to grow every year. A number of natural materials have been studied for their physiological effects and metabolism in order to develop them for use in skin-affi nity products: black tea gel (1) Morinda citrifolia seeds (2) Vitreoscilla fi liformis (3) Scutellaria baicalensis (4) as an anti- oxidant and anti-aging source Saxifraga stolonifera (5) as an anti-cancer agent Morus alba leaves (6) Glycyrrhiza uralensis (7) and Schisandra chinesis as a melanogenesis inhibitor. Address all correspondence to Sun Yeou Kim.

JOURNAL OF COSMETIC SCIENCE 506 Skin penetration of natural materials may be improved through fermentation, which in- creases the nutritive content of substances and reduces the particle size. Microorganisms are the key factor for fermentation (8), and Lactobacillus, Streptobacillus, and Bifodobacterium are usually used for cosmetic materials. Yoghurt is a fermented milk product that is often used in simple diets for atopic individuals (9), but there are currently no cosmetic prod- ucts based on yoghurt. We formulated a yoghurt-based facial mask, and conducted analyses to determine its bio- logical effects. This product also contains the Eastern prickly pear Opuntia humifusa Raf., which has been reported to have antioxidant and anti-infl ammatory activity. A member of the Cactaceae family, the Opuntia genus has antioxidative components, fl avonoids, quercetin, (+)-dihydroquercetin, and quercetin 3-methyl ether (10), which have radical scavenging and anti-infl ammatory activities (10–14). O. humifusa can tolerate low tem- perature (15). Recently, it has been successfully cultivated in winter in Korea (11). Because of its biological effects, Opuntia has been used as a food and cosmetic material, but it is always processed for these uses. We presume that is because when Opuntia comes into contact with water, it becomes viscous. We added intact Opuntia powder to yoghurt under the hypothesis that the ingredients would have a synergistic effect in terms of antioxidant and anti-infl ammatory activity. In this study, we examined changes in skin elasticity, moisture, melanin content, and ery- thema through in vivo tests and compared the results of our facial mask containing yoghurt and O. humifusa (F-YOP) to those of a control facial mask. MATERIALS AND METHODS PREPARATION OF YOGHURT Yoghurt base (commercial fermented milk) was added to sterile milk at 10 w/w% and then incubated at 42°C for 16 h, followed by overnight storage at 4°C. The yoghurt was mixed into a pack base of 4:6 (yoghurt:pack base). The pack base included de-ionized water, oil, and a viscosity-increasing agent (Table I). It is the same as the base of the con- trol product. The resulting product (completed yoghurt and pack base, YP) contained no preservatives. PREPARATION OF OPUNTIA HUMIFUSA RAF. We purchased freeze-dried O. humifusa powder (Goryeo Cactus, Seoul, Korea). The pow- der was prepared as 3 w/w%. Immediately prior to use, the powder was mixed completely with the YP. IN VITRO TESTS Scavenging activity on DPPH radicals. Radical scavenging activity of the Opuntia/YP com- ponents was determined according to Blosi’s method (1958), with some modifi cations (16). It was made from 0.2 mM DPPH (1,1-diphenyl-2-picryl-hydrazyl, Sigma, St. Louis, MO) solution using ethanol. The sample was dissolved in ethanol and was reacted with