203 Skin Barrier Enhancement by Saccharomyces The yeast essence balance lotion is comprised of: SRFF water butylene glycol propanediol dipropylene glycol 1,2-hexanediol glycerin Peg-8 methyl gluceth-10 phenoxyethanol. The control sunscreen cream (SPF 30 PA+++) is comprised of: water, arginine, sodium methyl stearoyl taurate, glyceryl stearate, diethylamino hydroxybenzoyl hexyl benzoate, octocrylene, bis-ethylhexyloxyphenol methoxyphenyl triazine, carbomer, ethylhexyl methoxycinnamate, ethylhexyl triazone, C20-22 alkyl phosphate, C20-22 alcohols, phenoxyethanol). TIGHT JUNCTION PROTEIN EXPRESSION (CLAUDIN-1, CLAUDIN-4, AND OCCLUDIN) The normal human epidermal keratinocytes (NHEKs) were cultured in keratinocyte growth medium in 75-cm2 flasks. Cells were harvested in log phase and seeded in a 96-well plate (2 × 104 cells/100 µL) and cultured overnight. After incubation, 100 μL of the fresh medium with or without a test sample was added. Epidermal keratinocytes were incubated with different concentrations of SRFF (3.13, 12.5, 50 µg/mL) and CaCl 2 (3 mmol/L) for 24 hours. After that, the cells were fixed on each well. The amounts of claudin-1, claudin-4, and occludin expressed on the surface of each cell were evaluated by the ELISA method. The following formula was used for promoting effects on claudin-1, claudin-4, and occludin production: Promoting rate on claudin-1, claudin-4, and occludin production (%) = A/B × 100 where A is the absorbancy with a test sample at λ 405 nm and B is the absorbancy without a test sample at λ 405 nm. Data are expressed as the mean ± standard error of the mean from six experiments. Differences between groups were evaluated using student’s t-test. A value of p 0.05 was considered to indicate statistical significance. CLINICAL STUDY TESTING METHODS A double-blind, placebo-controlled clinical evaluation was performed on 30 volunteers (female, aged from 25 to 35 years). All subjects had no obvious redness, skin lesions, scars, or other conditions on the face. All participants provided signed, informed consent at the beginning of the study. The investigation was performed in accordance with the ethical principles that have their origin in the Declaration of Helsinki and applicable regulatory requirements. Half-face testing. According to the random table, the volunteers applied the products daily on half their faces for 28 days. The yeast essence balance lotion containing the SRFF and sunscreen products were used on the left or right half of the face (including around the eyes), and only sunscreen products were applied on the other half of the face for 28 days. The clinical evaluation of the test area of the subject’s face was carried out through the specified time of D0, D14, and D28. On the test day, the subjects cleaned their faces with the cleansing products provided by the laboratory and then waited for 30 minutes in the laboratory environment with a temperature of 21 ± 1°C and a relative humidity of 50% ± 5%. The clinical evaluation was carried out on the subjects’ faces.

204 JOURNAL OF COSMETIC SCIENCE Skin barrier testing. Tape stripping was used to cause physical damage to the skin on the inner side of the forearm, resulting in damage to the skin barrier (manifested in an increase of the TEWL rate of the skin) and redness of the skin color (manifested in an increase of the a* value of the skin color). The experimenter marked one spot on each of the inner sides of the forearm of the subject, with a test area of 3 cm × 3 cm. Peel-off with adhesive tape was done for 15 times on each spot. After damage, the yeast essence balance lotion containing the SRFF and sunscreen cream as the test sample was used on one side, and the sunscreen cream as the blank control was used in the other area. TEWL and color were measured immediately (10 minutes) after application, MEASUREMENTS OF TRANSEPIDERMAL WATER LOSS Measurements of TEWL were performed using a Tewameter TM300 (Courage and Khazaka, Germany) to assess the integrity of the skin barrier. The evaluations of TEWL were carried out before peeling, after 15 times peeling, and 10 minutes later. Higher TEWL values reflect damaged skin barrier. COLORIMETRIC MEASUREMENTS Colorimeter CL 400 (Courage and Khazaka electronic GmbH, Germany) was used to measure the color of the skin, and the measuring values were expressed as coordinates in the color space a* (redness). The evaluation of color was carried out before peeling, after 15 times peeling, and 10 minutes later. CLINICAL EVALUATION BY DERMATOLOGISTS The dermatologists evaluated the efficacy of the product according to the facial condition of the subjects at D0 and D28 with one half or the face treated with the yeast essence balance lotion containing the SRFF and the sunscreen cream, and the other half of the face treated with sunscreen cream only. SUBJECT SELF-ASSESSMENT The subjects evaluated the efficacy of the product according to the facial condition (Table I). Figure 1. Icon of Maifuyin, Saccharomyces/rice ferment filtrate.