Seong-Joon Moon

Correlation between a Cutometer® and quantitative evaluation using Moire topography in age‐related skin elasticity

Background/purpose: As aging occurs, our skin gets more wrinkles, becomes drier and loses its elasticity. Validating the evaluation of skin elasticity is especially important, because it is not as visible as other signs of aging such as wrinkles. So it is needed that the method for measuring skin elasticity is able to reflect perception about the change of the skin state.

Comparison of objective and sensory skin irritations of several cosmetic preservatives.

There are many cosmetic ingredients, such as preservatives and fragrances, known to elicit adverse effects. The aim of this study was to investigate the side‐effects of cosmetic preservatives, by evaluating objective and subjective skin irritation. The method comprised of 2 parts. In part 1, we tried to compare 24‐hr patch test results with the sensory irritation potential of several preservatives. In part 2, skin cumulative irritation test for 21 days and sensory irritation test were performed to compare various combinations of preservatives in 4 types of formulations. Our data showed that methylparaben, ethylparaben, propylparaben, butylparaben, phenoxyethanol (PE) and chlorphenesin (CPN) have similar objective skin irritation potential at the minimal inhibitory concentration of each preservative, but CPN has higher potential than other preservatives in subjective irritation. Sensory irritation of preservatives changed according to formulation type, and PE combined with CPN highly increased irritation. There was correlation between antimicrobial activity and skin objective irritation but not sensory irritation. Influence on skin sensory irritation varies with the combination of preservatives. Therefore, for the development of new preservatives and cosmetics, it is important to evaluate skin sensory irritation of preservatives used in cosmetic products according to the type of formulations.

Comparison and correlation between stinging responses to lactic acid and bioengineering parameters

In evaluating the safety of a novel cosmetic product or a new chemical, it is important to assess susceptible population. One group of subjects is known to stingers who are more likely to experience sensory effects such as stinging and burning after contacting with cosmetics. The purpose of the study is to measure skin biophysical parameters noninvasively in stingers and non‐stingers and to see their correlations with stinging responses. 298 women were evaluated by modified lactic acid stinging test with 5% lactic acid solution rather than classic 10% solution because of strong reaction in Asian populations. Transepidermal water loss (TEWL), skin hydration, sebum content, and pH were measured using the bioengineering instruments in an environment‐controlled room. Correlations between stinging responses and skin biophysical parameters were statistically analysed. There was a positive correlation between stinging responses and TEWL evaluation. However, no correlations was observed between stinging responses and other parameters such as skin hydration, sebum content, and pH. Our data indicate that there is a relationship between the degree of stinging and the skin barrier function. However, we believe that various additional studies are necessary to characterize skin of stingers and the pathogenesis.

Silymarin inhibits melanin synthesis in melanocyte cells

Objectives The aim was to search for inhibitors of melanogenesis from natural resources.

Influence of polyol and oil concentration in cosmetic products on skin moisturization and skin surface roughness

Background/purpose: The purpose of this study is to investigate the optimum combination of polyols and oils in moisturizing cosmetic products to improve the human skin moisturization and skin surface roughness. Polyols and oils are essential ingredients in skin care products, but it is still not understood how their concentrations affect their efficacy and sensory properties on human skin. We investigated the effect of polyol and oil concentration on skin properties by noninvasive methods.

Alternative evaluation method in vitro for the water‐resistant effect of sunscreen products

Background/purpose: Sunscreen products today represent a trend of providing not only simple sun protection factor (SPF)/protection of UVA (PFA) but also other additional benefits. For example, as popularized by seasonless use of sunscreens, the special function of water resistance or sand proof is added to sunscreens as well as for leisure. Because a human in vivo test is time consuming and expensive, a screening process has been tried using an accurate in vitro system. In this study, we suggest the development of an in vitro test that can predict the result of in vivo water resistance of sunscreens.

Suitability of macrophage inflammatory protein-1β production by THP-1 cells in differentiating skin sensitizers from irritant chemicals

Background:  Worldwide restrictions in animal use for research have driven efforts to develop alternative methods.

Anti-Inflammatory Effects of the Mixture of Sorbus commixta, Urtica dioica, Phyllostachys nigra, and Rhus semialata Gall Extracts on LPS-induced Inflammation in HaCaT Cells

Lipopolysaccharide (LPS)-induced inflammatory responses in the HaCaT keratinocyte cell line produce proinflammatory cytokines, such as interleukin-1(IL-1), tumor neurosis factor- (TNF-), interleukin-6 (IL-6), and interleukin- 8 (IL-8) and also increase the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and prostaglandins E2 (PGE2). In this study, we developed new natural ingredients for cosmetics that inhibit the pro-inflammatory responses induced by LPS in HaCaT cells. The mixture of Sorbus commixta (SC), Urtica dioica (UD), Phyllostachys nigra (PN), and Rhus semialata gall (RS) extracts blocked the increase of TNF- IL-1 IL-6, and IL-8. The increase of COX-2, iNOS, and PGE2 were also blocked by it. Finally, the mixture inhibited skin irritation induced by sodium lauryl sulfate (SLS), when applied on skin through IQ chamber. In conclusion, these results show that the mixture of SC, UD, PN, and RS can be used as a primary ingredient to alleviate skin irritation when cosmeceutical products are developed for sensitive skin.

COMPARISON AND CORRELATION BETWEEN STINGING RESPONSES WITH LACTIC ACID STINGING TEST AND BIOENGINEERING PARAMETERS

from 9 48h to 9 5 min per application decreased the sensitization rate to 1% p-phenylene-diamine (PPD) from 54% to 3%. However, in a clinical study, infrequent longer duration and higher concentration exposure to PPD was significantly less likely to induce sensitization compared to more frequent, short duration, lower concentration exposure. Detailed statistical analysis of the results indicated that the most important factor driving the induction of skin sensitization was the number of exposures. An appreciation of such factors is vital for risk assessments where exposure is likely to be above the skin sensitization induction threshold.

A STUDY OF INFLUENCING FACTORS FOR SENSORY IRRITATION DUE TO PRESERVATIVES OF COSMETICS

화장품에서 홍반과 같은 피부 자극뿐만 아니라, 육안적으로 관찰되지는 않으나 소비자에게 불쾌감을 주는 따가움, 화끈거림, 가려움 등의 자극감을 평가하는 것도 중요하다. 스스로 민감성이라고 생각하는 사람들이 증가하는 추세에 자극감에 대한 연구는 더욱 중요해 지리라 여겨진다. 현재까지 자극감을 유발한다고 알려져 있는 알러지 있는 유발 화장품 원료는 lactic acid, glycolic acid, ethanol, 방부제류, 향료류, menthol 등이 있으며 pH가 증가할수록, 폐쇄 조건 등으로 흡수가 증가할수록 자극감이 증가한다고 알려져 있다. 본 연구에서는 화장품에서 많이 사용하고 있는 방부제 4종(methylparaben, propylparaben, phenoxye thanol, chlorophenecin)의 자극감에 영향을 주는 요인들을 찾아보고자 하였다. 연구 결과 팩 제형과 같은 흡수가 증가되는 제형에서와 그렇지 않은 제형에서의 방부제에 따른 자극감 결과에 차이를 보였다. 또한 서로 다른 방부제가 혼합된 경우에 상승 효과에 의하여 자극감이 높아지는 결과를 보인 경우도 있다. 무엇보다 phenoxyethanol과 chlorophenecin은 매우 미약한 자극감을 유발하였으나 혼합 사용한 경우에는 자극감이 상승되는 결과를 나타내었다. 이와 같은 결과로 보아 방부제에 의한 자극감은 제형에 의한 흡수 정도나 혼합되는 원료의 특성에 따라 자극감의 정도가 차이가 있는 것으로 보인다. 새로운 화장품의 원료의 선택시 이러한 영향을 함께 고려하여야 할 것으로 여겨진다. 【Sensory irritation is one of the important side effects of cosmetics and it is required to develop new products that are more tolerable to the consumers. There are lots of cosmetic ingredients known to induce sensory irritation such as lactic acid, glycolic acid, ethanol, preservatives, fragrances and menthol etc. It is also known that sensory irritation increases by change of pH as well as additional occlusive conditions. The aim of this study is to know various factors affecting sensory irritation due to preservatives (methylparaben, propylparaben, phenoxyethanol and chlorophenecin). We also wanted to investigate the effect of preservatives to sensory irritation according to change of formulations. Our results showed that sensory irritation increased with the conditions of increasing absorption such as packs. We have also found that sensory irritation increased synergistically when to apply two different preservatives together. For example, phenoxyethanol and chlorphenesin themselves have weak sensory irritation potentials, but we observed phenoxyethanol combined with chlorpenesin synergistically increase of sensory irritation potentials. In conclusion, formulation and combination of different preservatives should be considered to reduce the unwanted sensory irritation of preservatives.】