Seunghee Bae

Purpose: To examine the anti-melanogenic effects and underlying molecular mechanisms of Lactuca sativa L. stem extract (LSSE) in B16F10 murine melanoma cells. Methods: A LSSE was prepared using 70% ethanol as the solvent. Cell viability was determined using a water-soluble tetrazolium salt (WST-1)-based assay. To assess the anti-melanogenic effects of LSSE, intracellular melanin content, intracellular and mushroom tyrosinase activity, and the expression of melanogenesis-related genes and proteins were measured by reverse transcription-polymerase chain reaction and immunoblot analysis. Results: LSSE showed no significant cytotoxicity up to a concentration of 2.0%. Upon α-MSH stimulation, LSSE reduced melanin synthesis and cellular tyrosinase activity in a dose-dependent manner. Interestingly, LSSE also directly inhibited mushroom tyrosinase activity using L-tyrosine and L-DOPA as substrates. A marked reduction in the mRNA and protein expression of melanogenic enzymes, such as tyrosinase, tyrosinase-related Protein 1 (TRP-1), tyrosinase-related Protein 2 (TRP-2) was observed along with their transcription factor, microphthalmia-associated transcription factor (MITF). This was accompanied by downregulation of phosphorylated-protein kinase A (p-PKA) and -cAMP response element-binding protein (p-CREB) without altered total PKA and CREB protein levels. This indicates suppression of the PKA-CREB signaling pathway. Conclusion: LSSE attenuates melanogenesis by directly inhibiting tyrosinase activity and downregulating the PKA-CREB-MITF signaling pathway. LSSE shows potential as a safe and effective anti-melanogenic agent for cosmetic applications.

Purpose: To evaluate the skin barrier-enhancing, moisturizing, and antioxidant effects of CeraDeep™, which contains ceramide NP, ceramide AP, ceramide EOS, Oryza sativa (rice) bran oil, and hydrolyzed yeast protein, in human keratinocytes and to investigate its potential as a functional cosmetic ingredient. Methods: To examine the changes in keratinocyte differentiation-, lipid metabolism-, and moisturizing-related factors following CeraDeep™ treatment, quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis were performed. Lipid accumulation was determined through Oil Red O staining, and hyaluronic acid secretion was analyzed by enzyme-linked immunosorbent assay. Additionally, antioxidant activity was assessed using hydrogen peroxide (H2O2)-induced intracellular reactive oxygen species (ROS) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. Results: CeraDeep™ exhibited excellent skin barrier-related biological activity. Treatment with CeraDeep™ increased the expression of keratinocyte differentiation- and lipid metabolism-related factors and enhanced lipid accumulation. Additionally, the expression of moisturizing-related factors and secretion of hyaluronic acid were increased, indicating its potential to enhance moisturizing-related functions. CeraDeep™ also reduced H2O2-induced ROS generation and increased ABTS radical scavenging activity, demonstrating its potential to alleviate oxidative stress. Conclusion: This study confirmed that CeraDeep™ may exert complex effects on skin barrier formation, moisturization, and antioxidant activity, suggesting its potential as a functional cosmetic ingredient for enhancing skin barrier function.

Purpose: The beauty service industry relies heavily on direct interactions between service providers and customers; making the external image of beauty professionals an important factor that shapes customer expectations. This study empirically examined the effects of estheticians’ appearance image and professional uniform wearing on customer satisfaction and revisit intention among customers of aesthetic services. Methods: A survey was conducted among 204 adult men and women with prior experience using aesthetic services. The collected data were analyzed using SPSS WIN 27.0. Frequency analysis, one-way analysis of variance (ANOVA), and multiple regression analysis were employed to examine the relationships among the study variables. Results: First, significant differences in perceptions of estheticians’ appearance image and uniform wearing were identified according to respondents’age, educational level, and occupation. Second, all subfactors of estheticians’ appearance image—skin condition, body shape, and hairstyle had significant positive effects on customer satisfaction. Third, perceptions of uniform design significantly influenced customer satisfaction. Fourth, positive perceptions of estheticians wearing professional uniforms significantly increased both customer satisfaction and revisit intention. Conclusion: The findings indicate that estheticians’ appearance image and professional uniform wearing function as more than simple visual attributes. Rather, they play a critical role in fostering customer trust, enhancing emotional satisfaction, and encouraging behavioral outcomes, including revisit intention. This study contributes to both theory and practice by providing quantitative evidence that visual cues related to appearance and professional attire significantly influence customer perceptions and behavioral intentions in the aesthetic service industry.

Purpose: This study examined women’s level of beauty value pursuit during the COVID-19 outbreak, changes in nail makeup practices and maintenance patterns according to this level, and nail cosmetic purchasing behavior before and after the outbreak. Methods: The study targeted women in their 20s and older residing in the Seoul metropolitan area. Collected data were analyzed using SPSS WIN 25.0 through frequency analysis, one-way ANOVA, and χ2 (Chi-square) tests. Results: Women showed high levels of beauty value pursuit, particularly those with higher education, higher income, and self-employment status. Women with higher beauty value pursuit engaged more frequently in nail care. Following the COVID-19 outbreak, changes occurred in nail salon visit frequency and self-nail care frequency, along with increased spending on nail care. In addition, before the COVID-19 outbreak, nail cosmetics were most frequently purchased at drugstores, whereas after the pandemic, they were most commonly purchased online. However, no significant differences were observed according to beauty value pursuit level. Conclusion: This study found changes in nail care practices and management behaviors after the COVID-19 outbreak according to beauty value pursuit level and identified beauty value pursuit as an important factor influencing nail cosmetic purchasing behavior. These findings suggest the need to better understand consumers’ psychological characteristics when providing nail services and to offer tailored services that reflect these characteristics.

Purpose: The purpose of this study was to examine the relationship between the personal service quality of Korean skin care professionals and customer relationship persistence and revisit intentions. Methods: The study subjects were men and women with experience using skin care shops in Seoul and Gyeonggi Province. The collected data were analyzed using SPSS 25.0, including frequency analysis, t-tests, one-way ANOVA, and multiple regression. Results: The results are as follows. First, customers who visited Korean-style skincare shops at least once a week perceived higher levels of responsiveness and empathy from skincare therapists than those who did not. In addition, customers who visited two to three times per month showed greater relationship continuity with the skincare shop compared to those who did not. Furthermore, the more frequently customers visited Korean-style skincare shops, the higher their intention to revisit, particularly. Second, the higher the professionalism, responsiveness, and empathy of Korean-style skin care professionals, the higher the level of relationship persistence with the shops. Third, the higher the professionalism, responsiveness, reliability, and empathy of a Korean-style skin care professional, the higher the intention to revisit. Conclusion: To increase customer of relationship persistence and revisit intentions among Korean-style skin care salon customers, Korean-style skin care professionals must demonstrate trustworthy behavior, provide genuine service, provide professional skills, and provide systematic training and retraining.

Excessive accumulation of reactive oxygen species from exogenous and endogenous stressors can cause cellular damage. Chlorella contains diverse bioactive compounds, and violaxanthin, a major carotenoid pigment found in Chlorella sp. HS-V, has been reported to possess anti-inflammatory, anticancer, and antioxidant properties. We investigated the effect of violaxanthin on hydrogen peroxide (H₂O₂)-induced oxidative stress in human keratinocytes. Chlorella sp. HS-V extract significantly restored the H₂O₂-induced decrease in cell viability. Similarly, violaxanthin reduced H₂O₂-induced cytotoxicity and intracellular reactive oxygen species levels, which was associated with the upregulation of antioxidant enzyme expression. Under H₂O₂-induced oxidative stress conditions, violaxanthin may enhance cellular antioxidant defense by promoting nuclear factor erythroid 2-related factor 2 (NRF2) translocation through the phosphoinositide 3-kinase/protein kinase B/glycogen synthase kinase 3β (PI3K/AKT/GSK3β) signaling pathway. Additionally, violaxanthin improved H₂O₂-impaired wound healing in HaCaT human keratinocyte cells and reduced senescence-associated beta-galactosidase-positive normal human epidermal keratinocytes. Overall, these findings suggest that violaxanthin may serve as a potential therapeutic agent for mitigating oxidative stress-induced cellular dysfunction.

Purpose: This study examined how the MZ generation views vertical commerce. As an emerging key consumer group, the MZ generation significantly influences their makeup product purchasing behavior and satisfaction on these vertical commerce platforms. This study aims to provide foundational data to revitalize the specialized market for makeup products distribution.Methods: To achieve this objective, MZ generation consumers residing in Seoul and the metropolitan area were surveyed. The data collected were analyzed with SPSS WIN 27.0, using frequency analysis, chi-square (χ²) tests, t-tests, one-way ANOVA, and multiple regression analyses.Results: The MZ generation valued vertical commerce for its entertainment value, convenience, and economic efficiency. Almost all respondents (98.7%) had accessed a vertical commerce platform, and of those, 97.7% had purchased makeup products, with lip products being the most frequently purchased items. In general, customers were highly satisfied with makeup products purchased through vertical commerce platforms. Furthermore, higher levels of perceived entertainment value, convenience, and economic efficiency significantly increased purchase satisfaction.Conclusion: These findings indicate that positive perceptions of vertical commerce among the MZ generation significantly contribute to increased platform visits, enhanced makeup product purchasing behavior, and heightened purchase satisfaction. The findings offer valuable insights for developing strategies to activate and expand the distribution market for specialized makeup products through vertical commerce platforms.

Purpose: To investigate efficacy of a low-viscosity thioglycolate-based permanent wave technique on hair repeatedly damaged by cysteamine-HCl treatment and to hair-protective effects.Methods: Hair damage was induced using a cysteamine-HCl solution prior to permanent waving. In the control group, the hair was treated with a thioglycolate-based cream-type reducing agent (pH 8.9) for 15 min. The experimental groups received the same reducing agent for 10 min, followed by an additional low-viscosity, gel-type permanent solution at pH 4.5, 7, or 9 for 5 min to achieve a double-softening effect. Wave efficiency, hair diameter, tensile strength, elastic modulus, and hair damage were assessed, and hair surface morphology was examined by scanning electron microscopy (SEM).Results: The experimental group treated with the additional gel-type reducing agent at pH 4.5 showed significantly greater hair diameter, tensile strength, and elastic modulus, along with the lowest level of hair damage among the groups. The group treated with the additional gel-type reducing agent at pH 7 demonstrated significantly greater wave efficiency, tensile strength, and elastic modulus. SEM observations in all groups revealed structural damage to the cuticle caused by repeated chemical treatments.Conclusion: For hair repeatedly damaged by cysteamine-HCl treatment, a permanent waving strategy using an additional gel-type reducing agent at pH 7 is optimal for enhancing wave efficiency and elasticity, whereas the same strategy at pH 4.5 is more effective for minimizing hair damage and improving hair protection.

Purpose: This study aimed to evaluate the antimicrobial and biofilm-formation inhibition properties of polyols—1,2-hexanediol, 1,3-propanediol, and 1,2-butanediol—and acids—potassium benzoate and levulinic acid—as alternative preservatives for use in cosmetics.Methods: Minimum inhibitory concentration, minimum bactericidal concentration, and biofilm inhibition activities were ascertained. Representative pathogenic bacteria, such as Staphylococcus aureus and Pseudomonas aeruginosa, as well as beneficial skin bacteria, including Staphylococcus epidermidis and Corynebacterium accolens, were tested.Results: Among the three polyols, 1,2-hexanediol, which had the longest carbon chain, exhibited the most potent antimicrobial and biofilm-formation inhibitory activities against all tested species. Among the acids, levulinic acid was more effective than potassium benzoate. Notably, it demonstrated selective and potent suppression of pathogenic bacteria at low concentrations; however, higher concentrations were required with to inhibit beneficial bacteria. Additionally, all alternative preservatives exhibited superior biofilm suppression abilities compared to the positive control, ethanol. These effects demonstrated a dose-dependent increase and were quantitatively compared using the IC90 values.Conclusion: The findings provide fundamental data for the development of safe and effective alternative preservatives that can maintain the homeostasis of the skin microbiome. They offer important insights for future in vivo studies and innovations in cosmetic formulations.

This study investigated the effects of varying silicone oil viscosity on the physical structure and damage mechanisms of hair during permanent wave treatment of untreated hair (N), permanent wavy hair (P), and dyed hair (C). Hair treatments were formulated using dimethicone with viscosities of 6 cSt, 1,000 cSt, and 10,000 cSt. Wave efficiency, hair thickness, and tensile force were then evaluated. Hair cuticle, cross-sectional structure, and cuticle thickness were observed using FE-SEM, and elemental composition was analyzed using EDS. The results showed that wave efficiency was highest for untreated hair at VL_N, for permanent wavy hair at VM_P, and for dyed hair at VH_C. No significant differences were observed in hair thickness across all hair groups. Hair tensile force, cuticle thickness observed using FE-SEM, and sulfur (S) content analyzed using EDS — an important indicator of hair damage — all exhibited the highest values for VH in N, P, and C showing a consistent pattern. These findings indicate that wave curling performance and hair damage are significantly influenced by the silicone oil viscosity in hair treatments. This study provides fundamental and valuable data for determining the optimal silicone viscosity for hair treatments and may be expected to significantly contribute to the development of hair cosmetic products utilizing the benefits of silicone.