• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.99-104
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• 2007

The skin barrier function is one of the vital functions. Horny layer and epidermis among various skin layers play an important role in protecting body from environmental insults. Stratum corneum is completely formed by differentiation processes from the basal layer and newly formed corneocytes push the older ones from skin surface. In this study we investigated changes of various parameters - capacitance, transepidermal water loss (TEWL), pH and amount of removed corneocytes - according to the stratum corneum's depth. We removed the stratum corneum using tape stripping technique. We found that uppermost stratum corneum play an important role in skin surface moisturization and lower stratum corneum in protecting transepidermal water loss. In addition, skin pH is more acidic than surface pH. In the stratum corneum, skin pH is mote acidic in the deeper layer. Furthermore amount of removed corneocyte is also decreased according to depth because of stronger cell-cell union strength. From these results we suggest that stratum corneum has different characteristics depending on their position.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.4
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• pp.373-380
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• 2019

There are many differences in tran-epidermal water loss (TEWL), skin water contents, and skin elasticity, etc between face and forearm skin. In particular, our previous studies showed that elasticity of face skin was significantly differed from forearm depending on full hydration. So, we have studied the surface properties of corneocyte using atomic force microscopy (AFM), assuming that the differences between face and forearm skin would be associated with the surface properties of corneocyte. The surface roughness of corneocyte and villus-like projections (VPs) were measured. Furthermore, qualitative comparison among the surface of face, forearm, and lip corneocyte was performed. Corneocytes were collected by tape-stripping on both face and forearm of 8 volunteers, and the bottom surface of corneocytes were measured at 40 ㎛ × 40 ㎛ using AFM. Results showed that the lower surface roughness of face corneocytes was 388.34 ± 86.189 nm, and that of forearm corneocytes was 662.27 ± 224.257 nm, which confirmed that the lower surface of forearm corneocytes was more rough than that of face corneocytes (p < 0.001). Compared with the amount of VPs, lip corneocytes were the highest followed by face corneocytes, and forearm corneocytes were the lowest. From these results, it is conclued that the surface properties of corneocytes are somewhat involved in the property differences between the face and the forearm skin and VPs can be a useful parameter for the study of corneocyte by site. In addition, AFM is a very useful device for the comparative study of nano-structural differences on the surface of corneocytes. More studies can lead to develop a new evaluation method of corneocytes.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1219-1223
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• 2019

The skin condition varies by the parts of the face. This study intended to visualize the facial skin based on the characteristics including moisture, sebum, dryness, amount of dead skin cells, and roughness by sectionalizing the facial skin into 9 areas. A total of 98 female in their 20~35s were selected, and the characteristics of skin by area were selected and listed in the order, and the area they felt each characteristic most strongly was analyzed with a weight and the result was visualized. The result showed that the area where they felt dryness the most was around the lips and eyes, and the area where the largest amount of dead skin cells and rough skin existed was the chin. There was a significant increase in moisture content (p <.05), and 90.5% of satisfaction with dryness was satisfied. The result of this study will be used as a basic data for the development of a cosmetic mask pack or a functional cosmetic product for each part.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.355-364
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• 2023

Lips have a unique desquamation process and moisturizing properties that are structurally different from ordinary skin. In particular, the turnover cycle of the stratum corneum is fast and the outermost stratum corneum is thin, so the amount of keratin is relatively high, and there are no skin appendages, so it is very vulnerable to maintaining moisture. In this study, we set three targets for lip care : stratum corneum, moisture, and barrier, and aimed to identify the potential of three target-specific ingredients for lips improvement. We confirmed the exfoliating, moisturizing, and barrier improvement efficacy of three target-specific ingredients which also have mild exfoliating effect. Specifically, we verified that Bacillus clausii extract improved skin exfoliation, gluconolactone improved skin moisture retention, and serine reinforced skin barrier function. To test the in vivo efficacy of the complex composed of three target-specific ingredients on the human lips, the lip balm manufactured with non-irritating range of concentration was applied, and we confirmed that it was effective in improving lip exfoliation·moisturizing·elasticity·wrinkles. Consequently, it was confirmed that the beauty and health indicators of the lips could be improved through the exfoliation-moisturization-barrier care of the lips and these ingredients were applied to LG H&H LIPCERIN products.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.2 s.57
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• pp.81-88
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• 2006

Amino acid complex was made with the composition of amino acids quite similar to that of stratum corneum on the skin. In order to evaluate the efficacy of amino acid complex on the skin as an active cosmetic ingredient, we measured cytotoxicity. TIMP-1 expression, moisturizing effect and the amount of horny substance. In cytotoxicity assay, amino acid complex did not show any cytotoxicity. In moisturizing effect test using corneometer, it showed very good moisturizing effect. In TIMP-1 mRNA assay using RT-PCR, moo acid complex showed the increase of TIMP-1 expression, suggesting that amino acid complex have anti-wrinkle effect. Therefore, amino acid complex may be useful as an active ingredient for anti-aging.

• Applied Microscopy
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• v.40 no.4
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• pp.245-251
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• 2010

In this study, we applied 15% glycolic acid peeling agent and 30% glycolic acid peeling agent to the dorsal skin of mice and analyzed the oil content, moisture content, and pH value of the skin before and after test using cutometer. Ultrastructure for changes in the epidermis of mice were observed under a dermoscope and a scanning electron microscope before and after test. When using 15% glycolic acid peeling agent, the changes of moisture content was measured 74.67 AU for the normal control group and 70.21 AU for the experimental group, the oil content was 13.49 mg/$cm^2$ for the normal control group before test and 8.25 mg/$cm^2$ after test, and the pH value was 6.70 and 5.36 before and after test, respectively. When using 30% glycolic acid peeling agent, the moisture content was measured 74.46 AU for the normal control group before test and 53.50 AU for the experimental group after test, the oil content was 13.82mg/$cm^2$ and 5.70 mg/$cm^2$ before and after test, and the pH value was 6.45 and 4.58 before and after test, respectively. As such, it was found that the changes of moisture and oil content on the skin rely on the concentration of peeling agent and the degree of exfoliation of keratin. The surface of stratum corneum of mice with application of 15% glycolic acid peeling agent was relatively smooth and the exposed cellular surface of keratinocyte had some wrinkles. The surface of stratum corneum of mice with application of 30% glycolic acid peeling agent was smooth. No wrinkles were observed under high-resolution scanning electron microscope.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.4
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• pp.447-453
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• 2018

Acetyl hexapeptide 8 (AH8) is a synthetic peptide for anti-wrinkle cosmetics ingredient. It was developed as a mimetic of botox, patternd after N -terminal end of the protein synatosomal-associated protein 25 (SNAP25), a substrate of botulinum toxin. While AH8 has good efficacy and safety profiles, the permeation through the skin is poor. Therefore, we tried to enhance the transdermal delivery of AH8 by using of hyaluonic acid (HA), a linear polysaccharide of N-acetyl glucosamine and glucuronic acid. To investigate the effect of HA on AH8 penetration, we analyzed paraffin sections of $Micropig^{(R)}$ skin. Fluorescence labeled AH8 was applied to micropig skin with or without HA. The absorption of AH8 was limited to the stratum corneum (SC) without HA. On the other hand, AH8 penetrated to the dermis with HA. Especially, low molecular weight HA (5 kDa) was most efficient compared to 500 kDa HA and 2000 kDa HA. Experiments using fourier-transform infrared (FTIR) spectroscopy revealed that lower molecular weight HA had a tendency to increase the fluidity of the SC lipids more, which means enhancing the skin penetration. Therefore, HA could be expected to enhance the anti-wrinkle effect of AH8.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.388-396
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• 2003

The freeze dried young antler residue was extracted by proteases and hydrochloric acid(HCl). The young antler was extracted by water at 50$^{\circ}C$ and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 32.8%(absorbance 3.61 at 280nm) of bacteria protease, 23.8%(absorbance 0.69) of papain, and 31.2% (absorbance 2.96) of pepsin. The young antler was extracted by boiling water and the residue was reacted by proteases for 5 hours at 50$^{\circ}C$. The extraction rate of its residue was 45.0%(absorbance 3.61) of bacteria protease, 30.4%(absorbance 0.33) of papain, and 51.2% (absorbance 2.77) of pepsin. The result of HPLC analysis reveals that in 50$^{\circ}C$ water extract and boiling water extract, all high molecular peak was reduced under MW 1,000 by proteases. The result from the extract of young antler residue reacted by HCl for 5 hours at 50$^{\circ}C$ shows that its extraction rate was 45% (absorbance 0.78) in concentration of 0.1N HCl, 61% (absorbance 1.82) in 0.2N, 81% (absorbance 2.29) in 0.4N, and 82.0% (absorbance 3.28) in 2.0N. The result of HPLC analysis also reveals that in the extract by 0.8N HCl, the peak of about MW 70,000 accounted for 78% in total. Protein content of the extract by 0.8N HCl was 8.2%, and content of amino acid was 81.6%, ash was 1.3%, and mineral contents were 0.1 % of Ca, 2.3% of P, 0.8 % of Mg, 3.4% of Na, 0.002% of F by dry base.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.492-504
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• 2018

This study was conducted to investigate the effects of seaweed peeling (SP), glycolic acid peeling (GP) and general scrub (GS), which are widely known as cures for acne in both medicine and esthetics on the keratosis pilaris skin and provide basic data for a keratosis pilaris improvement program. For the experiment, subjects were categorized into control (GS) and experimental (GP and SP) groups, and tests were performed on arms and legs with relatively high keratosis pilaris symptoms (5 parts for each group) for 6 weeks. The keratin quantity, sebum content, moisture level and pigmentation were measured before and after (2, 4 and 6 weeks) the experiment and comparatively analyzed. The GP group showed an increase in moisture level (t=-4.064, p<0.01) but a decrease in pigmentation (t=3.536, p<0.01), while a decrease in keratin quantity (t=2.370, p<0.05) and pigmentation (t=4.017, p<0.01) was observed in the SP group and a decrease in keratin quantity (t=2.834, p<0.05) and an increase in moisture level (t=-7.589, p<0.001) was observed in the control group (GS). Additionally, the skin irritation reaction was lowest in the GS group. The SP group had the highest satisfaction with the improvement in response to keratosis pilaris care. When asked if they were willing to get the treatment with the same product, both SP and GP groups were high. In other words, keratosis pilaris care was needed in both experimental and control groups. Overall, the results of this study indicate that SP, GP and GS, which are commonly used in remedying acne, normalize turnover cycle by removing the dead cells from around the pores and improve keratosis pilaris symptoms by increasing moisture in the skin. Therefore, to improve keratosis pilaris skin, it is important to keep removing keratin and using a moisturizer that provides a skin barrier on a regular basis. The results presented herein will be useful as basic data for a keratosis pilaris improvement program.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.2
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• pp.113-119
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• 2015

The measurement of hydration level in the surface layer of the skin, stratum corneum (SC), gives important information on the biophysical properties and function of the skin barrier such as softness, flexibility, and healthiness of the skin. But it is difficult to measure a consistent hydration level from a sample to another sample due to individual variations and environmental changes. The aim of this study was to evaluate objective hydration after using various products in the SC. The SC Hydration was measured by capacitance (Corneometer$^{(R)}$, C+K, Germany) on the ventral site of forearm from 40 healthy volunteers. The skin surface was chronologically measured immediately after application of the test products and 3 and 6 hours later. We analyzed the averages of five measurements of each site and used the hydration increase rate for correction on untreated site variation. We found that most polyols including glycerol and butylenes glycol influenced directly the hydration increase rate in the SC previously. In this study, glycerol was used to prepare the standard products from 0 to 20 percents and applied to the same volunteers. The individual standard curve showed linear relation to glycerol concentrations. Based on the the standard curve, hydration of SC was converted into hydration increase rate to glycerol concentrations. The converted glycerol concentrations of products were repetitive and reproducible. In addition, the individual standard curve was used to relate the skin type of each individual. These results suggest that the hydration of the SC standardized regardless of external variation and individual skin condition can explain detailed skin state variation. Further studies will be conducted with other ingredients such as surfactants, lipids and aqueous materials, and with other methods for noninvasive measurement.