International Journal of Cosmetic Science最新文献

Objective: We investigated skin hydration and anti-ageing efficacies of Ectoine, a natural bacterial osmolyte, utilising human keratinocyte (HaCaT) and fibroblast (Hs68) cells under non- or UVB (30 mJ/cm²) exposure.

Methods: We incorporated various experimental techniques, including MTT assay (cell viability), small interfering RNA (siRNA) transfection, and immunoblotting analysis, to assess the molecular mechanisms of skin hydration and anti-ageing efficacies of Ectoine.

Results: The findings exhibited that Ectoine improved cell viability in the presence or absence of UVB exposure in HaCaT cells. Ectoine upregulated Src and HAS-2 expression in the presence or absence of UVB irradiation in HaCaT cells. Src knockdown reduced Ectoine-increased HAS-2 expression, implying that Ectoine provoked Src-mediated HAS-2 expression in the presence of or without UVB irradiation in HaCaT cells. Ectoine enhanced phosphorylated-ERK expression in a time- and dose-dependent manner in HaCaT cells. In addition, Ectoine increased phosphorylated-ERK expression in UVB-irradiated HaCaT cells. The ERK inhibitor (PD98059) remarkably decreased Ectoine-provoked HAS-2 expression, suggesting that Ectoine triggered ERK-mediated HAS-2 expression in HaCaT cells. Furthermore, Ectoine amplified JNK and AQP-3 levels in the presence or lack of UVB exposure in HaCaT cells. The JNK inhibitor (SP600125) significantly reduced Ectoine-triggered AQP-3 expression, suggesting that Ectoine provoked JNK-mediated AQP-3 expression in HaCaT cells. Ectoine increased collagen-I expression in the presence or lack of UVB irradiation in HaCaT cells. Notably, Ectoine enhanced collagen-I expression and inhibited MMP-1 expression in a dose-dependent manner in fibroblast (Hs68) cells.

Conclusion: We demonstrated that Ectoine exerts skin hydration effects without or with UVB exposure in human skin keratinocyte (HaCaT) cells and anti-ageing in fibroblast (Hs68) cells. Therefore, Ectoine could serve as a potential natural compound in cosmetic preparations for skin hydration and anti-ageing.

Background: The stratum corneum is essential for maintaining the skin barrier and preventing transepidermal water loss. Damage to this layer increases skin sensitivity, potentially leading to inflammation and related complications.

Aims: This study aimed to establish reproducible skin damage models and to develop a non-invasive classification method for assessing the severity of skin barrier damage.

Materials and methods: Two controlled models of injury, tape stripping (TS) and friction-induced injury, were used to simulate barrier impairment. Raman imaging was employed to analyze biomarkers, including stratum corneum thickness, lipid content, and keratin levels. These parameters were combined with the K-nearest neighbour (KNN) algorithm to categorize skin damage severity.

Results: The integrated KNN-based model successfully classified skin damage severity ranging from normal to severe. It also enabled the prediction of severity in unknown samples, providing a robust diagnostic framework.

Discussion: This non-invasive model demonstrates strong potential for diagnostics and monitoring in dermatology.

Conclusion: KNN-based classification combined with Raman imaging offers a reliable method for evaluating skin barrier damage severity.

Objective: Improvement of application, performance, colour predictability and stability of plant-based hair colourants derived from Lawsonia inermis L. by investigating the release mechanism of lawsone during extraction and optimizing processing conditions to prevent its premature formation. A two-component system was developed, consisting of naturally occurring lawsone precursors (hennosides) in one formulation and a catalytic agent (β-glucosidase) in another.

Methods: Henna raw material was extracted using maceration, Soxhlet, and industrial-scale methods with various solvents. Extracts were analysed for yield and content of lawsone, hennosides, polyphenols, metals and reducing sugars. HPLC quantified lawsone and hennosides; reducing sugars and polyphenols were measured using dinitrosalicylic acid and Folin-Ciocalteu assays, respectively. Yak hair was dyed with different formulations and evaluated for colour outcome and wash fastness using the CIELab colour system.

Results: Formulations containing pre-released lawsone were unstable and ineffective after 4 weeks. In contrast, gel formulations containing hennosides without β-glucosidase remained stable for over 8 weeks and produced consistent colour when combined with the enzyme before application. Ethanolic extraction effectively yielded hennoside-rich extracts without lawsone formation. Aqueous extraction at boiling point also produced hennoside-rich extracts. Soxhlet extraction resulted in β-glucosidase activity remaining in the starting material. The two-component gel formulation demonstrated comparable wash fastness and colour intensity to the conventional paste, with improved ease and speed of application and rinsing.

Conclusion: Optimizing henna extract processing and formulation design enabled the development of a more user-friendly, effective and stable plant-based hair dye, supporting broader consumer adoption.

Objective: The cosmetics industry increasingly prioritizes the development of formulations that are both safe and effective. This study aimed to investigate the synergistic anti-inflammatory effects of pterostilbene (Pt) and honokiol (Ho) in lipopolysaccharide (LPS)-stimulated THP-1 macrophages and to evaluate their systemic safety using the Threshold of Toxicological Concern (TTC) framework.

Methods: Human THP-1 monocytes were differentiated with PMA and stimulated with LPS to model inflammatory conditions. Pt and Ho were tested individually and in combination for their ability to suppress macrophage proliferation and proinflammatory cytokine production (TNF-α, IL-1β, IL-6). Synergistic effects were assessed through combination index and isobolographic analyses. NF-κB pathway modulation was evaluated via Western blot, and molecular docking was performed to explore compound-target interactions. Maximum systemically safe concentrations were calculated using TTC values integrated with default dermal absorption percentages and product-specific exposure parameters.

Results: Pt and Ho significantly inhibited LPS-induced macrophage proliferation and cytokine production, both individually and in combination. Combination index and isobologram analyses confirmed synergistic suppression of cytokines at low, non-cytotoxic concentrations. Both compounds attenuated NF-κB activation; however, no statistical synergy was observed at the signalling level, indicating coordinated but distinct mechanisms. Molecular docking revealed direct binding of Pt to NF-κB, while Ho exhibited no appreciable binding, further supporting mechanistic divergence. TTC-based calculations established systemically safe concentration limits for Pt and Ho across various cosmetic product categories.

Conclusion: Pt and Ho exert synergistic anti-inflammatory effects in macrophages and can be safely used within systemically acceptable concentration limits in cosmetic formulations. These findings support their development as a multifunctional combination targeting inflammation-related skin conditions, while underscoring the need for further investigation into dermal safety, optimized dosing strategies and broader mechanistic pathways.

Objective: Following hair coloration with home or salon-applied hair dyes, sometimes it is desirable to have the option of removing this new colour and returning the hair to its natural appearance. This can either be immediately after coloration if the client does not like the colour, or it may be that a client wishes to 'reset' their hair and almost start again. There are oxidative and reductive methodologies to remove hair dye: (i) The oxidative method utilizes persulfate-based products, which are very difficult to control; however, professional hairdressers understand the limitations of what is possible without causing excessive oxidative damage to the hair fibre. (ii) The reductive method to remove dyes utilize sulfinate-based reducing agents commonly used in the textile industry. Commercial products based on these reducing agents have been, and are still being, used to 'decolour' dyed hair, albeit with significant drawbacks. The objective of this study was to introduce formamidine sulfinic acid and demonstrate its effective removal of hair dye in a safe and effective manner without the drawbacks of alternative reducing agents.

Methods: This paper describes and critically assesses the use, performance and drawbacks of ascorbic acid, sodium hydrosulfite, sodium hydroxymethanesulfinate (aka sodium oxymethylene sulfoxylate) and formamidine sulfinic acid as colour removal agents against different types and classes of hair dyes on human hair, and compares the various outcomes.

Results: The formamidine sulfinic acid system presented herein is an extremely effective reducing agent for use in removing colour from dyed hair. It works extremely well on all types and systems of colourants including permanent oxidative colourants (from different manufacturers) which represent the majority of products used in the hair coloration market.

Conclusion: The colour removal effectiveness of sodium hydroxymethanesulfinate (sodium oxymethylene sulfoxylate) is good, but it has three drawbacks: (i) it produces formaldehyde, (ii) the colour can return and (iii) can result in unpredictable shades on subsequent oxidative colouring. The formamidine sulfinic acid system presented herein is extremely effective and gives excellent colour removal results across different colourant systems with the added benefit that it does not have the drawbacks that the other systems have.

Objective: This study examined the ethnic and longitudinal (proximal 'root' vs. distal 'tip') variations in hair properties across Caucasian, Chinese and Indian populations, focusing on electrokinetic behaviour, structural features and particle deposition. The aim was to use electrokinetic analysis to determine how ethnicity and weathering affect hair health and influence hair-product interactions.

Methods: Streaming potential measurements were conducted on chemically untreated ponytail samples from Caucasian, Chinese and Indian donors to determine zeta (ζ)-potentials. Particle deposition was studied using amine-grafted polymethyl-methacrylate (PMMA) particles, while cross-sectional properties were quantified using optical microscopy. Root and tip segments were analysed separately to evaluate weathering effects.

Results: Cross-sectional analysis revealed huge strand-to-strand variability within individuals. Chinese hair exhibited larger cross-sectional areas and perimeters compared to Indian and Caucasian hair, with minimal differences between the root and tip regions. For both root and tip, ζ-potential magnitudes ranked Caucasian > Indian > Chinese with no significant root tip variations despite tips enduring over 2 years of additional weathering. Similar root and tip ζ-potentials resulted in similar particle deposition for the same sample. Generally, particle deposition rates correlated with surface coverage, but ζ-potential values did not greatly influence deposition rate, with highly negatively charged Caucasian hair samples having slower deposition rates than the other ethnicities. However, a more negative ζ-potential resulted in higher surface coverage within each ethnic group. Despite Caucasian hair's more negative ζ-potential, it had the lowest average particle surface coverage (θ_Caucasian = 3-10%, θ_Indian = 6-16%, θ_Chinese = 5-20%), suggesting other factors such as hydrophilicity influence deposition. Ethnicity influenced pH-ζ profiles, with Caucasian hair exhibiting the steepest overall gradients and the highest isoelectric point (IEP), suggesting relatively less oxidative damage. A pH-ζ classification framework is proposed to aid in analysing surface functionalities.

Conclusion: Hair properties are shaped by genetic, environmental and cultural factors. While surface charge guides particle deposition, our findings reveal distinct ethnicity-dependent behaviours, necessitating further research into other surface properties. Smaller sample sizes reduced variability, enabling hypotheses on classifications and surface functional groups, which may serve as a foundation for future studies.

Objectives: Machine-based cyclic combing of hair tresses under dry conditions is a proven method for evaluating hair strength and the impact of treatments. Recent advancements in image analysis allow for a detailed review of hair fragment lengths and quantities produced after specific combing cycles. Our aim is to provide an in-depth analysis of the kinetics of hair fragment formation.

Methods: We analysed the combing performance of untreated and bleached European straight hair, assessing two conditioning treatments. Hair tresses underwent 5000 combing cycles, with the increasing number of fragments recorded. Results were fitted using a three-parameter Voigt-Kelvin model.

Results: The fragment counts were log-normally distributed in all cases. The model uses ln(N₀) to indicate early fragment release, showing higher numbers for bleached hair compared to untreated hair, which significantly drop with conditioner treatments. The ln(N_∞) parameter estimates the maximum expected fragments. The Failure Cycle Index (FCI) remains largely unchanged across materials according to its 95% confidence limits.

Conclusions: The selected function's characteristics and the invariance of FCI indicate that friction primarily controls fragment formation in straight hair during combing. This suggest that there is no direct link between combing performance and tensile fatigue failure for this hair type. In contrast, textured hair will likely show more complex combing performance. Our analysis shows that the total number of fragments after many combing cycles can predict early failures and assess conditioning agents, thereby supporting product claims about 'hair strength'.

In the human face, the lips play a key role in social interactions and are a major element of makeup strategies. However, the amount of data available on lips, particularly relating to colour, is limited in comparison to that on skin. To gain a better understanding of lip colour, this study aimed to assess its diversity across four ethnicities (Asian Chinese, African American, Hispanic American and Caucasian American and French). The final objective was to develop a lip colour chart to guide cosmetic product development. A total of 514 women aged from 19 to 68 years were recruited in the USA, France and China. Their natural lower lip colour was measured with a full-face hyperspectral imaging system, SpectraFace® (Newtone Technologies, Lyon, France). The data showed a large variety in lip colour between and within each ethnicity. Important overlaps were found between ethnic groups, particularly and surprisingly between Hispanic and Asian women. This allowed for the development of a lip colour chart composed of 53 lip tones, based upon lightness and hue, as a global reference guide for lip colour assessment. Hispanic women showed the largest diversity, represented in 32 of the chart tones. The present study revealed a large lip colour diversity across four ethnic groups. The inter-group overlaps demonstrate that lip colour is not solely defined by individual ethnic belonging. The 53 lip tones described here could be used as target shades to create more inclusive nude lipsticks in the near future.