Showing papers in "International Journal of Cosmetic Science in 2019"

18β-Glycyrrhetinic acid: its core biological properties and dermatological applications.

Abstract: Recently, attention has been focused on identifying natural herbal compounds with high biological activity, especially antioxidative, anti-inflammatory and antimicrobial properties, for preventing and controlling various skin conditions, including inflammation-related diseases such as atopic dermatitis and UV-induced skin photoaging. One key active plant ingredient is 18β-glycyrrhetinic acid (GA), the main metabolite of glycyrrhizin (GL), obtained from licorice root. The review examines the valuable biological properties of GA, particularly those playing key roles in the treatment of various dermatological disorders in humans. The review highlights the key anti-inflammatory, antioxidant and antimicrobial properties of GA and its toxicity towards normal cells lines. It also examines the physicochemical properties of GA and presents methods of increasing its penetration through the stratum corneum and bioaccumulation with the use of modern delivery systems such as liposomes and nanoemulsions.

Evolution of the use of antioxidants in anti-ageing cosmetics.

Abstract: Objective Skin health and beauty are a cornerstone of general well-being in humans. Anti-ageing cosmetics are used to provide a healthy and youthful appearance. Among the different cosmetic actives, antioxidants are incorporated in anti-ageing products due to their beneficial effects in preventing and minimizing the signs of skin ageing. This work aims to understand how anti-ageing formulations changed in the past 7 years regarding pure antioxidants composition. Methods Data were collected from anti-ageing formulations commercialized in main stores and pharmacies in the Portuguese market. The study started on 2011 and was updated with products launched or whose composition has been renewed on 2013, 2015 or 2018. Results Ascorbic acid and tocopherol and their derivatives were consistently the most used antioxidants in anti-ageing formulations; followed by niacinamide and retinyl palmitate. Seven ascorbic acid derivatives are currently used in anti-ageing formulations while only three tocopherol derivatives were identified in this study. Several combinations of antioxidants were routinely found, mainly tocopherol (or tocopherol derivatives) with other antioxidants and tocopherol with tocopherol derivatives. We have not identified emerging antioxidants with great impact in anti-ageing formulations even though niacinamide and retinyl palmitate exhibited over 10% more usage in 2018. Conclusion This insight is relevant to the cosmetic industry providing a better understanding of the scientific-based formulation of modern cosmetics and supports the need for innovative antioxidants in anti-ageing cosmetics.

Main features and applications of organogels in cosmetics.

Abstract: Cosmetic treatments aim at improving skin appearance through vehicles of good sensory properties. Those vehicles are mainly emulsions and gels designed to deliver safe and effective compounds to skin. Creams and serums are widely used to achieve these goals, but recently a new type of formulation known as organogels triggered scientific attention, particularly in the design of both topical and cosmetic formulations. It has been established that the lipophilic nature of organogels makes it an excellent candidate for the delivery of cosmetic molecules through skin. In this review, we discuss the properties and characteristics of organogels and present the advantages of the application of these systems in cosmetics.

Mechanisms of anionic surfactant penetration into human skin: Investigating monomer, micelle and submicellar aggregate penetration theories.

Abstract: OBJECTIVE Once penetrated into the stratum corneum, anionic surfactants bind to and denature stratum corneum proteins as well as intercalate into and extract intercellular lipids. With repeated exposures, this leads to skin dryness and irritation, compromising barrier function and skin health. The mechanisms of anionic surfactant penetration into the skin, however, are still widely debated. The objective of this study was to evaluate current theories of surfactant penetration into human skin. METHODS A test set comprising 15 anionic surfactant systems and one non-ionic surfactant, all having either dodecyl or lauryl alkyl chains, was tested for surfactant penetration into split-thickness human cadaver skin in vitro using radiolabelled sodium dodecyl sulphate (14 C-SDS). Select physical properties of these formulations thought to be associated with skin penetration including critical micelle concentration, micelle diameter, filtrate concentration and zeta potential were also measured. RESULTS 14 C-SDS penetration into human cadaver skin from surfactant systems in vitro was found to correlate well with CMC (R2 = 0.34, P < 0.05), filtrate concentration (R2 = 0.36, P < 0.05) and zeta potential (R2 = 0.76, P < 0.001), but poorly with micelle diameter (R2 = 0.12). Furthermore, the latter measure correlated inversely with penetration compared to what would be expected based on the micelle penetration theory. CONCLUSION Neither monomer nor micelle penetration theories are sufficient to explain anionic surfactant penetration into human skin. Submicellar (or premicellar) aggregate penetration theory is difficult to defend at relevant surfactant concentrations. We propose a new hypothesis for this mechanism in which short-term penetration is based on monomer concentration and longer term penetration is based on surfactant-induced damage to the skin barrier.

Facial skin mapping: from single point bio-instrumental evaluation to continuous visualization of skin hydration, barrier function, skin surface pH, and sebum in different ethnic skin types.

Abstract: Dry skin is one of the most important concerns of consumers worldwide. Despite huge efforts over several decades, the personal care industry still does not offer a perfect solution to satisfy the unmet needs of consumers for moisturising treatments in different ethnic groups. The paucity of data for the underlying cellular and biochemical problems in, and the effects of moisturisers on photodamaged facial skin may partly explain this. Mainly, single point measurements are used to understand the effects of products on skin physiology even on surrogate skin sites such as the non-photodamaged volar forearm. Some groups have developed discontinuous facial maps of skin biophysical properties, however, in 2014 a continuous facial analysis of bio-instrumental evaluations was developed using a heat map approach. These maps enabled a continuous visualization of features that not only revealed an unexpected complexity of facial skin but also indicated that use of surrogate skin sites for facial skin is inappropriate. We have demonstrated that remarkable gradients of skin hydration, TEWL, skin surface pH and sebum exist within short distances across the face and the gradients are distinctive among different ethnic groups. In addition, these studies have demonstrated that darkly-pigmented individuals do not necessarily have a better skin barrier function than their less-pigmented counterparts and that Caucasians have a lower facial skin surface pH compared with more pigmented subjects. Overall, there are no correlations between capacitance, TEWL and skin surface pH including individual topology angle values. Novel 3D camera approaches have also been used to facilitate a more precise assignment of measurement sites and visualisation. The 3D facial colour mappings illustrated precisely the local moisturising effects of a moisturising cream. There were subtle ethnic differences in efficacy that may be related to underlying skin biochemistry and/or ethnic differences in product application. A placebo-controlled study using conductance measurements in Chinese subjects is also reported. Finally, a new whole face statistical approach has been taken to prove differences in skin parameters but also of moisturiser treatment that adds further to our understanding of the ethnic differences in skin physiology and product application. This paper reviews the background of the development and application of this methodology.

A new procedure, free from human assessment that automatically grades some facial skin structural signs. Comparison with assessments by experts, using referential atlases of skin ageing

Abstract: Objective To develop an automatic system that grades the severity of facial signs through 'selfies' pictures taken by women of different ages and ethnics. Methods 1140 women from three ethnics (African-American, Asian, Caucasian), of different ages (18-80 years old), took 'selfies' by high resolution smartphones cameras under different conditions of lighting or facial expressions. A dedicated software, was developed, based on a Convolutional Neural Network (CNN) that integrates training data from referential Skin Aging Atlases. The latter allows to an immediate quantification of the severity of nine facial signs according to the ethnicity declared by the subject. These automatic grading were confronted to those assessed by 12 trained experts and dermatologists either on 'selfies' pictures or in live conditions on a smaller cohort of women. Results The system appears weakly influenced by lighting conditions or facial expressions (coefficients of variations ranging 10-13% for most signs) and leads to global agreements with experts' assessments, even showing a better reproducibility on some facial signs. Conclusion This automatic scoring system, still in development, seems offering a new quantitative approach in the quantified description of facial signs, independent from human vision, in many applications, being individual, cosmetic oriented or dermatological with regard to the follow-up of medical anti-ageing corrective strategies.

Blue light disrupts the circadian rhythm and create damage in skin cells

Abstract: On a daily basis, the skin is exposed to many environmental stressors and insults. Over a 24-h natural cycle, during the day, the skin is focused on protection; while at night, the skin is focused on repairing damage that occurred during daytime and getting ready for the next morning. Circadian rhythm provides the precise timing mechanism for engaging those different pathways necessary to keep a healthy skin through clock genes that are present in all skin cells. The strongest clue for determining cellular functions timing is through sensing light or absence of light (darkness). Here, we asked the question if blue light could be a direct entrainment signal to skin cells and also disrupt their circadian rhythm at night. Through a reporter assay for per1 transcription, we demonstrate that blue light at 410 nm decreases per1 transcription in keratinocytes, showing that epidermal skin cells can sense light directly and control their own clock gene expression. This triggers cells to "think" it is daytime even at nighttime. Elsewhere, we measured different skin cell damage because of blue light exposure (at different doses and times of exposure) vs. cells that were kept in full darkness. We show an increase in ROS production, DNA damage and inflammatory mediators. These deleterious effects can potentially increase overall skin damage over time and ultimately accelerates ageing.

Renewable sources: applications in personal care formulations.

Abstract: A global tendency for products considered environmentally sustainable, and ecologically obtained led the industry related to personal care formulations to fund the research and the development of personal care/cosmetics containing ingredients from natural resources. Furthermore, consumers are aware of environmental and sustainability issueans, thus not harming the environment represents a key consideration when developing a new cosmetic ingredient. In this study we review some examples of active ingredients or raw materials used in cosmetics/personal care/biomedical products that are coming from either through biotechnological systems, or as byproducts of several industries. A skin formulation containing biosynthetic actives, prepared by us and the study regarding its dermocosmetic properties are also described. The need for the standardization processes, the safety assessment tools, the improvement of the exploitation methods of these renewable sources in order the production to be ecologically and economically better are also discussed.

Transepidermal UV radiation of scalp skin ex vivo induces hair follicle damage that is alleviated by the topical treatment with caffeine.

Abstract: Objectives Although the effect of ultraviolet radiation (UVR) on human skin has been extensively studied, very little is known on how UVR impacts on hair follicle (HF) homeostasis. Here, we investigated how solar spectrum UVR that hits the human skin surface impacts on HF biology, and whether any detrimental effects can be mitigated by a widely used cosmetic and nutraceutical ingredient, caffeine. Methods Human scalp skin with terminal HFs was irradiated transepidermally ex vivo using either 10 J/cm2 UVA (340-440 nm) + 20 mJ/cm2 UVB (290-320 nm) (low dose) or 50 J/cm2 UVA + 50 mJ/cm2 UVB (high dose) and organ-cultured under serum-free conditions for 1 or 3 days. 0.1% caffeine (5.15 mmol/L) was topically applied for 3 days prior to UV exposure with 40 J/cm2 UVA + 40 mJ/cm2 UVB and for 3 days after UVR. The effects on various toxicity and vitality read-out parameters were measured in defined skin and HF compartments. Results Consistent with previous results, transepidermal UVR exerted skin cytotoxicity and epidermal damage. Treatment with high and/or low UVA+UVB doses also induced oxidative DNA damage and cytotoxicity in human HFs. In addition, it decreased proliferation and promoted apoptosis of HF outer root sheath (ORS) and hair matrix (HM) keratinocytes, stimulated catagen development, differentially regulated the expression of HF growth factors, and induced perifollicular mast cell degranulation. UVR-mediated HF damage was more severe after irradiation with high UVR dose and reached also proximal HF compartments. The topical application of 0.1% caffeine did not induce skin or HF cytotoxicity and stimulated the expression of IGF-1 in the proximal HF ORS. However, it promoted keratinocyte apoptosis in selected HF compartments. Moreover, caffeine provided protection towards UVR-mediated HF cytotoxicity and dystrophy, keratinocyte apoptosis, and tendential up-regulation of the catagen-promoting growth factor. Conclusion Our study highlights the clinical relevance of our scalp UV irradiation ex vivo assay and provides the first evidence that transepidermal UV radiation negatively affects important human HF functions. This suggests that it is a sensible prophylactic strategy to integrate agents such as caffeine that can act as HF photoprotectants into sun-protective cosmeceutical and nutraceutical formulations.

A linear viscoelastic model to understand skin mechanical behaviour and for cosmetic formulation design

Abstract: Objectives Skin is arguably one of the most important organs that plays an active role in our everyday biological functions after brain. Owing to the wide range of applications in medicine, cosmetics industry and more recently robotics, skin research has gained tremendous attention with respect to its mechanical behaviour. Various macro modelling approaches are available for modelling skin's mechanical behaviour. The objective of this paper is to study skin's mechanical property change with age and demonstrate anti-ageing effects of cosmetic formulations from skin mechanical property change perspective. Methods In this study, skin's mechanical behaviour was modelled using a 1D linear viscoelastic phenomenological model and the model was validated using two sets of experimentally observed skin data (strain, stress relaxation and cyclical loading). The model was further modified to study the effect of the presence of a thin layer of cosmetic polymer and to demonstrate anti-ageing effects of the cosmetic polymer from the perspective of change in the mechanical behaviour of skin with cosmetic layer. Results The estimated values of skin mechanical properties from the model agree with those in literature. The extracted model features show good correlation with skin age (viscosity and time constant). The results from our model indicate that the cosmetic polymers enhance the mechanical properties of skin significantly. Conclusions This work will find its applications in designing and testing anti-ageing formulations. This model can be used to filter various combinations of cosmetic formulations by knowing the mechanical response of polymer on skin, thereby accelerating the product development.

The influence of age, gender and race/ethnicity on the composition of the human axillary microbiome.

Abstract: Objective The microbial community plays an important role in the generation of human axillary odour by transforming odourless natural secretions into volatile odorous molecules. A limited number of traditional culturing methods and molecular based research have been performed to characterize the human axillary microbiome in small collection sample sizes. Moreover, only a few have considered the interpersonal variations across age, gender or race/ethnicity, and none have included all three variables within one single study. The aim of this study was to characterize the axillary microbiome of healthy subjects across different age groups, genders and races/ethnicities in a large sample size. Methods The underarm skin swab samples were collected from 169 healthy subjects. The axillary microbiome was analysed by IS-pro, a clinically validated high-throughput DNA fingerprinting technique. Results The results indicate that the senior subjects (55+) tend to have a higher number of total bacterial than younger adults (of a defined age). The diversity of odour causing bacteria, e.g. corynebacteria, increases with age. Among the three races/ethnicities studied, East Asians have a unique microbial composition compared to Caucasians and Hispanics, which may contribute to the different odour profiles observed among the races/ethnicities studied. Conclusion Human axillary microbiome varies by age, gender and race/ethnicity. This study has provided an unprecedented fundamental knowledge about the axillary microbiota as a function of age, gender and race/ethnicity.

An efficient method to determine the Hydrophile-Lipophile Balance of surfactants using the phase inversion temperature deviation of C i E j /n-octane/water emulsions

Abstract: Objective The aim of this study was to develop a fast and an efficient method to determine the Hydrophile-Lipophile Balance (HLB) number of cosmetic and pharmaceutics surfactants. Methods This method is based on the deviation of the phase inversion temperature induced by the addition of the test compound, with respect to the phase inversion temperature of a reference system, which includes an ethoxylated surfactant. This method is called PIT-deviation. Results Three calibration curves are set up with three reference ethoxylated surfactants. These calibration curves make it possible to evaluate the interfacial behaviour of certain chemicals. More particularly, these curves make it possible to easily determine the surfactant HLB. Conclusion In this study, a fast and accurate method has been developed to determine the hydrophilic-lipophilic balance (HLB) number of amphiphilic chemicals. This new method can be applied to establish an HLB number of all commercial amphiphilic ingredients. Compounds which have a PIT-deviation close to zero are also discussed.

Potentially beneficial effects of rhamnose on skin ageing: an in vitro and in vivo study.

Abstract: Objective Recent findings showed that skin ageing preferentially affects human papillary dermal fibroblasts suggesting that the papillary dermis represents a critical zone altered by skin ageing. Based on these findings, we investigated the potential anti-ageing effect of rhamnose. Methods We investigated the potential anti-ageing effect of rhamnose using in vitro reconstructed skin containing fibroblasts obtained either from young or old donors, and in vivo clinical investigation. Results We detected positive effects of rhamnose in both epidermal and dermal compartments of in vitro reconstructed skin. Moreover, we were able to show that such in vitro findings were also obtained in vivo including an effect on collagen IV and procollagen I production. Conclusion We provide evidence that rhamnose has a potentially beneficial effect on papillary dermis and dermal-epidermal junction, both of the areas which are affected by skin ageing.

Clinical impacts of sun exposures on the faces and hands of Japanese women of different ages

Abstract: Objective To assess the impacts of sun exposures on some skin signs on the faces and hands of differently aged Japanese women, according to their distinct behaviours towards vis a vis sun exposure. Methods Two comparable cohorts of Japanese women (aged 18-83 years) were created according to their usual behaviour towards sun exposure i.e. non-sun-phobic (N = 495) and sun-phobic (N = 516) and through their regular use(s) of a photo-protective product. Standard photographs (full-face and 45° lateral) allowed to focus on 18 facial signs that were graded by 15 experts, using a referential skin ageing Atlas. From these two cohorts, two sub-cohorts (114 and 122 women) were created with regard to the similar clinical aspects of the dorsal side of their hands (Left vs. Right) that were further graded. Absolute differences in the scores of each sign were used (non-sun-phobic minus sun-phobic), by age-ranges, to better ascertain the impact of sun exposures and photo-protection. Results Facial signs related to skin wrinkles/texture and pigmentary spots were found significantly more accentuated among non-sun-phobic women and show an early onset (20-30 years). Facial sagging and crow's feet wrinkles appear delayed (30-40 years). The severity of vascular disorders was found to be similar in the two cohorts. The absolute differences in the grading's of almost all signs were unsurprisingly found increased with advancing ages, illustrating the combination of chronological and photo-ageing processes. With regard to hands, differences in skin texture and pigmentary disorders are of a late onset (40-50 years) and were found much increased at older ages. The cutaneous signs of the hands of Japanese women can hardly be taken as reliable markers of their photo-ageing status. Conclusion The present work illustrates, for the first time, some specificities of the impact of sun exposures on the facial skin of Japanese women, pinpointing the fact that some facial signs are of an early onset. Results significantly confirm the importance of both sun avoidance coupled with photo-protective measures.

An automatic procedure that grades some facial skin structural signs: agreements and validation with clinical assessments made by dermatologists.

Abstract: OBJECTIVE To confirm the robustness and validity of an automatic scoring system, algorithm-based, that grades the severity of nine facial signs through "selfies" smartphones pictures taken by European Caucasian women through dermatological assessments. METHODS 157 Caucasian women from three countries (France, Germany, Spain), of different ages (20-75 years), took one "selfie" image by the frontal camera of their smartphones whereas local dermatologists photographed them with the back camera of the same smartphone. The same nine facial signs of these subjects were initially graded by these local dermatologists, using referential Skin Aging Atlases. All 314 "selfies" images were then further automatically analyzed by the algorithm. The severity of facial signs (wrinkles, pigmentation, ptosis, skin folds etc.) were statistically compared to the assessments made by the three dermatologists, taken as ground truth. RESULTS Highly significant coefficients of correlation (P < 0.001) were found in the three cohorts between the grades provided by the system and those from dermatologists in live. The back camera - of a better resolution than the frontal one - seems affording slightly more significant correlations. However, although significantly correlated, the signs of vascular disorders and cheek skin pores present some disparities that are likely linked to the technical diversity of smartphones or self-shootings, leading to lower coefficients of correlations. CONCLUSION This automatic scoring system offers a promising approach in the harmonization of Dermatological assessments of skin facial signs and their changes with age or the follow up of anti-aging treatments.

Bio-derived hydroxystearic acid ameliorates skin age spots and conspicuous pores.

Abstract: INTRODUCTION We report on the preparation and efficacy of 10-hydroxystearic acid (HSA) that improves facial age spots and conspicuous pores. METHODS The hydration of oleic acid into HSA was catalyzed by the oleate hydratase from Escherichia coli. Following treatment with HSA, collagen type I and type III was assessed in primary human dermal fibroblasts together with collagen type III, p53 protein levels and sunburn cells (SBC) after UVB irradiation (1 J cm-2 ) by immunohistochemistry on human ex vivo skin. UVB-induced expression of matrix metalloprotease-1 (MMP-1) was determined from full thickness skin by RT-qPCR. Modification of the fibroblast secretome by HSA was studied by mass-spectrometry-based proteomics. In a full-face, double blind, vehicle-controlled trial HSA was assessed for its effects on conspicuous facial pore size and degree of pigmentation of age spots in Caucasian women over an 8-week period. RESULTS HSA was obtained in enantiomeric pure, high yield (≥80%). Collagen type I and type III levels were dose-dependently increased (96% and 244%; P < 0.01) in vitro and collagen type III in ex vivo skin by +57% (P < 0.01) by HSA. HSA also inhibited UVB-induced MMP-1 gene expression (83%; P < 0.01) and mitigated SBC induction (-34% vs. vehicle control) and reduced significantly UV-induced p53 up-regulation (-46% vs. vehicle control; P < 0.01) in irradiated skin. HSA modified the fibroblast secretome with significant increases in proteins associated with the WNT pathway that could reduce melanogenesis and proteins that could modify dermal fibroblast activity and keratinocyte differentiation to account for the alleviation of conspicuous pores. Docking studies in silico and EC50 determination in reporter gene assays (EC50 5.5 × 10-6 M) identified HSA as a peroxisomal proliferator activated receptor-α (PPARα) agonist. Clinically, HSA showed a statistically significant decrease of surface and volume of skin pores (P < 0.05) after 8 weeks of application and age spots became significantly less pigmented than the surrounding skin (contrast, P < 0.05) after 4 weeks. CONCLUSION HSA acts as a PPARα agonist to reduce the signs of age spots and conspicuous pores by significantly modulating the expression of p53, SBC, MMP-1 and collagen together with major changes in secreted proteins that modify keratinocyte, melanocyte and fibroblast cell behavior.

Microrheological study of ternary surfactant-biosurfactant mixtures.

Abstract: Objective The main objective of this paper is to understand the rheological impact of rhamnolipids biosurfactant (mono/dirhamnolipids mixture, CCB) on a common personal care mixed surfactants system: anionic sodium laureth sulfate (SLES) and zwitterionic cocamidopropyl betaine (CAPB). The ternary biosurfactant/surfactants mixtures were evaluated at three different formulation conditions. The experimental results can provide a formulation guideline when applying rhamnolipids in cosmetics and personal care products. Methods Traditional mechanical rheometer was used to measure bulk viscosity and lower frequency rheological behaviour of ternary surfactant mixtures. Diffusing wave spectroscopy (DWS) was utilized to access rheological responses at high frequency regime. Structural parameters such as contour length, entanglement length and persistence length of wormlike micelles in the anionic/zwitterionic/biosurfactant mixtures can be extracted from the rheological data gathered by DWS. Results Maxwellian type response was present in SLES/CAPB/CCB system which indicated the formation of wormlike micelle. Contour length of wormlike micelle formed by SLES/CAPB reduced from 445.8 to 88.37 nm with only 2 wt% addition of CCB. In the same system, viscosity decreased and shorter relaxation time were observed. Addition of sodium chloride built the viscosity of SLES/CAPB/CCB to an extent by screening charges between surfactant head groups. Highest viscosity of SLES/CAPB/CCB (10 wt%, 2wt% and 4wt% respectfully) was observed when sodium chloride concentration was at 4 wt%. In the same SLES/CAPB/CCB system, pH impacted the system's rheological response significantly. Due to the zwitterionic nature of CAPB, it became more cationic at lower pH while rhamnolipids became more nonionic. SLES still maintained its anionic nature at low pH and this promoted the interaction between CAPB and SLES. At lower pH, overall loss and storage modulus exhibited higher values while longer relaxation times were observed. Increase in micelles contour length under lower pH conditions were shown by the DWS data. Conclusion This preliminary rheological and microstructure study of the complex biosurfactant/surfactants ternary systems revealed the effect of formulation conditions on the mixtures rheological responses.

Photoageing-related skin changes in different age groups: a clinical evaluation by biophysical and imaging techniques.

Abstract: Objectives In view of the lack of studies about the morphological and structural changes caused by solar radiation in young people, the aim of the present study was to evaluate the photoageing-related changes in the skin of different age groups by biophysical and imaging techniques. Methods Forty-four healthy female subjects were divided into two age groups: Group 1 (G1): 18-35 years old and Group 2 (G2): 40-60 years old. The skin of malar region of the face was evaluated in terms of mechanical properties, disorder in the pigmentation pattern, morphological and structural changes using the Cutometer® , Colorimeter® , Visioface® and Dermascan C® devices and reflectance confocal microscopy (Vivascope® ). Results The results showed that the main changes in the skin of G1 were related to the pigmentation pattern, the papilla format and depletion of thin collagen fibres. These alterations were also observed in the skin of G2, but with more pronounced effects. Conclusion The knowledge about the skin changes caused by photoageing obtained in this study is very important for the development of dermocosmetic products for more effective treatments particularly focused on this type of skin. Finally, objective characterization of photoageing showed the importance of photoprotective habits since the first years of life in order to retard the appearance of skin changes caused by solar radiation.

Synchronized in vivo measurements of skin hydration and trans-epidermal water loss. Exploring their mutual influences

Abstract: Objective To explore the relationship between skin surface hydration and Trans-Epidermal Water Loss (TEWL) when simultaneously measured. Methods Six circular skin areas of the forearms (3 per forearm, 3 cm in diameter) of 12 Caucasian women were used as models. 4 prototypes of formulae of different compositions containing glycerol at different concentrations 7%, 10% and 40% were used as models of hydrating products. One formula (glycerol-free) was used as control vehicle. Standardized applications of formulae (2 mg/cm2 ) were performed on 5 skin sites chosen at random, the other being left as bare/control. A recently marketed instrumental device that records the skin surface hydration and TEWL on a small skin area in a simultaneous manner was used. Measurements were carried out at T0 (pre-application), at 1 h (T1) and 5 h (T5) post applications on two close sites within the 6 defined areas of both forearms. Results The new instrumental device allowed to clearly differentiate the 5 formulae (i.e. 7% vs. 10%) with regard the dose effect brought by glycerol (7%, 10%, 40%) and to record their lingering effects at T1 and T5. Both parameters were found significantly and negatively correlated, i.e. the higher the skin hydration, the lower the TEWL. The 40% concentration of glycerol, that leads to the highest skin hydration, brings a drop in the TEWL by about a two-fold factor. Skin hydration of bare skin and control/vehicle sites showed minor and non-significant changes along 5 h. Instead, the control/ vehicle slowed down the TEWL to a slight extent. Conclusion The use of this new instrumental device shed a new light on the mutual and inverse relationships between skin hydration and TEWL. Results suggest that, at high concentration, glycerol leads to largely increase the water content of both epidermal and dermal compartments, possibly leading to structural changes in the skin relief.

A human skin model to evaluate the protective effect of compounds against UVA damage.

Abstract: Objective The main function of skin is to protect the body from external aggressions. Over time, normal skin ageing is accelerated by external stresses such as smoking, pollution, chemical products and radiation. UV light, in particular UVA, causes DNA damage, apoptosis and morphological modifications, which are responsible for both premature ageing and cancer. The aim of this study was to establish a discriminatory and sufficiently reproducible cutaneous model for evaluating UVA damage, to enable testing for effectiveness of potentially protective compounds. Methods The cutaneous model is based on Human skin explants irradiated with UVA. Deleterious effects on epidermis were observed and quantified by haematoxylin-eosin staining and by immunofluorescence of ɣ-H2Ax, cytokeratin 5, involucrin and loricrin protein. Dermis deterioration was evaluated by transmission electronic microscopy and zymography in situ. Results We were able to observe and quantify deleterious effects associated with UVA irradiation: epidermal and dermal disruption, appearance of Sunburn cells, increased DNA damage and induced apoptosis. The use of this model in the evaluation of protective compounds was first confirmed using sunscreens, then further validated with a panel of active ingredients which showed beneficial effects on epidermis morphology and DNA integrity after UVA exposure. Conclusion We have developed a model and a standardized protocol, based on the use of human skin explants, which allows us to explore the protective effect of active ingredients to environmental stresses such as UVA.

Attenuation of negative effects of senescence in human skin using an extract from Sphingomonas hydrophobicum: development of new skin care solution

Abstract: Objective Intrinsic skin ageing is mainly caused by cellular senescence. p16 and p21 are two important tumour suppressor proteins that play essential roles during cell proliferation and ageing through regulating the expression of several genes. Moreover, physical changes between the ages of 55 and 60 years affect one's physical and disrupt self-esteem. The cosmetics industry has focused on bioactive substances derived from natural products such as plants, mushrooms and marine algae to counteract the deleterious effect on skin senescence. Besides these products, compounds produced by bacteria may decelerate individual senescence. Methods In order to evaluate the potential benefits of bacteria extract over skin ageing, we investigated whether a Sphingomonas hydrophobicum (SH) extract is able to protect our skin against senescence mechanisms. We used an ageing full-thickness skin equivalent model, which was treated or not with the bacteria extract in a systemic way for 42 days. p21 and p16 and senescence-associated galactosidase activity were used to detect cellular senescence with immunohistology. Using a psychobiological approach, we evaluated in vivo the effect of SH extract on self-esteem, isotropy and suppleness. Results Sphingomonas extract significantly suppressed senescence associated with β-galactosidase activation. It also significantly inhibited the expression of cell cycle inhibitors (p21 and p16). At the same time, the bacteria extract has a significant positive impact on the issue by increasing the expression of versican and fibrillin-1. Significant improvements of self-esteem were reported after 56 days of SH extract application. These psychological benefits were accompanied by a significant improvement in skin suppleness and isotropy. Conclusion Sphingomonas extract delays intrinsic skin ageing process by inhibiting cellular senescence, and has also the capability to restructure the skin. These beneficial physiological effects induced by SH extract have a positive influence on self-esteem. Because skin ageing causes emotional distress, SH extract can serve as an anti-ageing cosmeceutical agent and help to build a better psychological health, and help individuals to assume ageing.

Inhibitory effects of Sanguisorba officinalis root extract on HYBID (KIAA1199)-mediated hyaluronan degradation and skin wrinkling.

Abstract: Objectives Hyaluronan (HA), an important constituent of extracellular matrix in the skin, has many biological activities such as hydration that contributes to firmness and bounciness of the skin. We have reported that reduction in HA in the papillary dermis and over-expression of HYBID (HYaluronan Binding protein Involved in hyaluronan Depolymerization, alias KIAA1199 or CEMIP), a key molecule for HA degradation in skin fibroblasts, are implicated in facial skin wrinkling in Japanese and Caucasian women. However, little or no information is available for substances which inhibit the HYBID-mediated HA degradation. Methods Inhibition of Sanguisorba officinalis root extract and ziyuglycoside I, one of the components of Sanguisorba officinalis root extract, to the HYBID-mediated HA degradation was assessed by size-exclusion chromatography of HA depolymerized by stable transfectants of HYBID in HEK293 cells (HYBID/HEK293 cells) or normal human skin fibroblasts (Detroit 551 cells and NHDF-Ad cells). The HYBID mRNA and protein expression was examined by quantitative real-time PCR and immunoblotting in the skin fibroblasts treated with Sanguisorba officinalis root extract, and size distribution of newly produced HA was evaluated by preparing metabolically radiolabelled HA. A double-blind, randomized and placebo-controlled study was carried out in the 21 healthy Japanese women, who were topically treated with the formulation containing Sanguisorba officinalis root extract or the placebo on each side of the face including crow's foot area. Results Sanguisorba officinalis root extract, but not ziyuglycoside I, abolished HYBID-mediated HA degradation by HYBID/HEK293 cells. Sanguisorba officinalis root extract also inhibited HYBID-mediated HA degradation in skin fibroblasts by down-regulating HYBID mRNA and protein expression. Although control untreated skin fibroblasts produced polydispersed HA, the cells treated with Sanguisorba officinalis root extract produced only high-molecular-weight HA. Treatment with Sanguisorba officinalis root extract-formulated lotion significantly improved skin elasticity, and reduced skin wrinkling scores at the outer eye corner compared with the placebo formulation. Conclusion Sanguisorba officinalis root extract showed an anti-HYBID-mediated HA degradation activity and anti-wrinkle activity on human facial skin, which is accompanied by the improvement in elasticity. Our study provides the possibility of a new strategy to inhibit HYBID-mediated HA degradation for anti-wrinkle care.

Assessing changes in some facial signs of fatigue in Chinese women, induced by a single working day.

Abstract: Background The impacts of physical fatigue upon some facial signs, induced by a whole day work, have been previously described on Caucasian women. This study aimed at assessing those possibly experienced by Chinese working women under comparable conditions. Material and methods Standard photographs of 60 Chinese women working in the same company (aged 20-40 years) were taken at three occasions during their working day (just before, at 4 and 8 h). Focusing on facial signs allowed a panel of experts to grade their respective severities, helped by a referential atlas dedicated to Asian skin. A naive panel, comprising 64 Chinese women (aged 20-60 years) graded, through an analogic 0-10 scale, the global facial aspect of each subject, particularly its tired-look and dullness and estimated the age of each subject (perceived age). Paired-comparisons in blind and random modes (T0/T4, T4/T8, T0/T8) allowed this naive panel to assess the subjects with a younger/older look, a dullest aspect. Results A daily work induces, in Chinese women, changes in some facial signs (Nasolabial, Periorbital and Inter-ocular wrinkles, Cheek skin pores). The latter appear more marked between T0 and T4 than between T4 and T8. As compared to those observed among Caucasian women, these changes, although subtle, are of a higher amplitude and concern different facial signs. The naive panel allowed to describe an increase in the tired look and dullness along the day, more so among the older group (31-40 years), together with an increased perceived age. Tired look, dullness and perceived age appear strongly linked. Conclusion Despite some possible differences in working conditions, some facial signs of Chinese women seem more affected by a fatigue induced by a working day in urban environment, than those of Caucasian women in similar conditions.

Olive oil inhibits ageing signs induced by chronic stress in ex vivo human skin via inhibition of extracellular-signal-related kinase 1/2 and c-JUN pathways.

Abstract: Objective Chronic stress-induced oxidative damage and protease synthesis cause a loss of extracellular matrix components promoting human skin ageing. The administration of antioxidant compounds, such as those observed in olive oil, may attenuate stress-induced ageing signs in human skin. Thus, the aim of this study was to investigate the effect of olive oil administration in ex vivo stressed human skin. Methods Explants of human skin were treated with high levels of epinephrine (as observed in stressed patients) and olive oil in medium for 13 days. Cultures treated with medium alone were used as controls. Results Olive oil reversed the high epinephrine level-induced reduction in epidermis and dermis thickness and collagen fibre content in ex vivo human skin. The increase in the production of reactive oxygen species (ROS) and malondialdehyde levels (an index of lipid peroxidation) promoted by high levels of epinephrine were also attenuated by olive oil in ex vivo human skin. Moreover, olive oil was able to reverse the high epinephrine level-induced increase in extracellular signal-related kinase 1/2 (ERK 1/2) and c-JUN (a major component of transcription factor AP-1) phosphorylation and protein matrix metalloproteinase-2 (MMP-2) expression in ex vivo human skin. Conclusion Olive oil attenuates stress-induced ageing signs (thinner dermis and collagen fibre loss) in ex vivo human skin by reducing MMP-2 expression, ROS production, and ERK 1/2 and c-JUN phosphorylation.

A natural skin anti-ageing serum containing pseudobulb ethanolic extract of Grammatophyllum speciosum: a randomized double-blind, placebo-controlled trial.

Abstract: OBJECTIVE Grammatophyllum speciosum is utilized to treat sore throats and bronchitis In Thai folk medicine. This study evaluated the in vitro activity and clinical efficacy of a G. speciosum pseudobulb decoction. METHODS Measure of in vitro anti-ageing activity was performed using non-cell based assays as well as in CRL 2097 human fibroblast cells. A prophetic patch test method was used to determine skin irritation in 24 healthy Thai volunteers. A randomized double-blind, placebo-controlled trial was conducted with 24 subjects for 56 days after facial application to evaluate efficacy. The results were measured with Visioface® and Cutometer® MPA 580 as well as by visual observations. RESULTS The total content of the antioxidant polyphenols in G. speciosum ethanolic extract (GSE) was 48.19 ± 0.39 mg EGCG equivalent per gram. The GSE possessed potent and higher anti-elastase activity more than EGCG. The extract was able to protect human fibroblasts against superoxide anion-induced cell death at the concentration of 10 µg mL-1 . In a clinical study, facial application of the serum containing 0.5% GSE was found to safely increase skin distensibility in healthy volunteers. Skin viscoelasticity and wrinkle volume were also significantly reduced (P < 0.05). CONCLUSION Thus, both the in vitro and the clinical studies have illustrated the anti-wrinkle/anti-ageing benefits of GSE on human skin.

Incorporation of Cró thermal water in a dermocosmetic formulation: cytotoxicity effects, characterization and stability studies and efficacy evaluation

Abstract: Objective Development of cosmetic formulations to provide a controlled release of hydrophilic active compounds from mineral medicinal waters constitutes an attractive challenge. The objective of this study was the development and the characterization of a dermocosmetic gel formulation with Cro thermal water, from Beira Interior of Portugal, as a major functional ingredient. Methods Concentrations of mineral chemical elements of Cro thermal water were previously determined by inductively coupled plasma-optical emission spectrometry or mass spectrometry and cytotoxicity assays using thermal water were carried out on normal human dermal fibroblasts (NHDF) cells. Then, the Cro thermal water was included (more than 90%) in a developed gel formulation that was characterized through rheological and texture analysis and submitted to stability assays during 30 days. The effects on the skin volunteers, namely skin pH, the degree of hydration, transepidermal water loss and skin relief, were evaluated through non-invasive biometric techniques. A gel formulation including purified water was used as a control. Results Cro thermal water is rich on several chemical elements in particular sodium, silica, potassium and calcium besides some trace elements, with important functions for the skin. NHDF cells adhered and proliferated in the presence of thermal water confirming the biocompatibility of the major component of the gel formulation. The developed gel formulation based on thermal water resulted in an improvement of textural parameters, comparing with the purified water-based one. Significant improvements in the cutaneous biometric parameters (degree of hydration, transepidermal water loss and skin relief) of volunteers were also registered for the gel formulation containing thermal water. Conclusion This study demonstrated for the first time the potential benefits of Cro thermal water in a gel formulation to be used in cosmetic and dermatological applications.

Can plant-derived phytochemicals provide symptom relief for hair loss? A critical review.

Abstract: It is known that hair growth disorders and hair loss can cause personal distress and affect well-being. Whilst clinical conditions remain a target for medical research, current research on hair follicle biology and hair growth control mechanisms also provides opportunities for a range of non-medical and cosmetic interventions that have a modulating effect on the scalp and follicle function. Furthermore, an improvement of the hair fibre characteristics (cuticle structure, cortex size and integrity) could add to the overall positive visual effect of the hair array. Since phytochemicals are a popular choice because of their traditional appeal, this review provides a critical evaluation of the available evidence of their activity for hair benefit, excluding data obtained from animal tests, and offers recommendations on improving study validity and the robustness of data collection in pre-clinical and clinical studies.

Changes in epidermal morphology associated with dandruff

Abstract: Objective Dandruff is a very common scalp condition characterized by flaking and pruritus usually with no visible signs of inflammation, such as redness and erythema. Dandruff is considered a multifactorial condition with both microbial colonization and host factors such as sebum production thought to play a role. There is evidence of changes in epidermal morphology in the scalp skin of dandruff sufferers, with reports of an increase in mean thickness and more nucleated cell layers. The underlying mechanisms driving these morphological changes are currently unclear. The objective of this study was to fully characterize epidermal morphology in dandruff compared to healthy scalp skin and to evaluate potential mechanisms underlying any changes observed. Methods Scalp skin biopsies were taken from 22 healthy female subjects and 21 dandruff sufferers, from both lesional and non-lesional sites. Samples were processed, sectioned and stained using haematoxylin and eosin (H&E). To fully characterize epidermal morphology, measurements were taken of epidermal thickness, the convolution of the dermal-epidermal junction and the depth of epidermal rete ridges. To analyse changes in epidermal proliferation immunohistochemical staining was performed using Ki67, a well-established marker of cell proliferation, and quantified using image analysis. Results Histochemical analysis of skin sections revealed that in dandruff lesional samples, the epidermis was thicker, had a more convoluted dermal epidermal junction and the rete ridges were elongated, compared to healthy scalp skin. Similar directional changes in epidermal morphology, were observed in non-lesional dandruff samples, albeit to a lesser extent. Image analysis of Ki67 expression in the epidermis revealed dandruff lesional skin contained significantly more Ki67-positive proliferating keratinocytes than healthy controls samples. This suggests dandruff scalp skin epidermal keratinocytes are in a hyper-proliferative state. Conclusion There were significant changes in epidermal morphology in dandruff lesional skin compared to healthy scalp skin including increased epidermal thickness, a more convoluted dermal-epidermal junction and elongation of rete ridges. Interestingly, we found there was evidence of an increase in the percentage of epidermal Ki67-positive cells, which has not been reported previously, and demonstrates dandruff is a condition displaying epidermal hyper-proliferation.

Application of biophysical and skin imaging techniques to evaluate the film‐forming effect of cosmetic formulations

Abstract: Objective Products with film-forming effect, or 'second skin', which guarantees an immediate protective effect after application, is a highlight, especially when composed of natural ingredients. Thus, the objective of this study was to evaluate the immediate film-forming effect on skin of a gel and emulsion formulations added with Kappaphycus alvarezii and Caesalpinia spinosa extracts through biophysical and skin imaging techniques, especially with the Reflectance Confocal Microscopy (RCM). Methods The measurements were done in the forearm region before (baseline) and 1 h after of application of the developed formulation and its control. The parameters related to the stratum corneum water content, transepidermal water loss (TEWL), cutaneous microrelief and morphological and structural characteristics of the epidermis were analysed through the following biophysical and skin imaging techniques: Corneometer® CM 825, Tewameter® TM 300, Visioscan® VC98 and Vivascope® 1500, respectively. A sensorial analysis was also performed to study how the formulations were perceived on the skin. Results The obtained results showed that the active ingredient under study allows the film formation on the skin surface, leading to a reduction of TEWL and skin desquamation. The obtained images from RCM showed a reduction of furrows on the skin surface and a film formation after a single application of the formulations. However, these effects were more pronounced in the emulsion formulation, which suggests a synergistic effect of the active ingredient under study with the emollients of formulation composition. This result was also observed in the sensorial analysis, as both formulations added with the active substance were well evaluated. Conclusion The presence of Kappaphycus alvarezii and Caesalpinia spinosa extracts in the studied cosmetic formulations, enabled a film formation on a skin surface, bringing benefits as a reduction of transepidermal water loss and skin desquamation, as well as a furrows reduction and an improvement of stratum corneum after 1 h of application. Finally, the skin imaging techniques can be suggested as an excellent tool to evaluate a film-forming effect of cosmetic formulations.

Mass spectrometry-based proteomics reveals the distinct nature of the skin proteomes of photoaged compared to intrinsically aged skin.

Abstract: Objective With increasing age, skin is subject to alterations in its organization, which impact on its function as well as having clinical consequences. Proteomics is a useful tool for non-targeted, semi-quantitative simultaneous investigation of high numbers of proteins. In the current study, we utilize proteomics to characterize and contrast age-associated differences in photoexposed and photoprotected skin, with a focus on the epidermis, dermal-epidermal junction and papillary dermis. Methods Skin biopsies from buttock (photoprotected) and forearm (photoexposed) of healthy volunteers (aged 18-30 or ≥65 years) were transversely sectioned from the stratum corneum to a depth of 250 μm. Following SDS-PAGE, each sample lane was segmented prior to analysis by liquid chromatography-mass spectrometry/mass spectrometry. Pathway analysis was carried out using Ingenuity IPA. Results Comparison of skin proteomes at buttock and forearm sites revealed differences in relative protein abundance. Ageing in skin on the photoexposed forearm resulted in 80% of the altered proteins being increased with age, in contrast to the photoprotected buttock where 74% of altered proteins with age were reduced. Functionally, age-altered proteins in the photoexposed forearm were associated with conferring structure, energy and metabolism. In the photoprotected buttock, proteins associated with gene expression, free-radical scavenging, protein synthesis and protein degradation were most frequently altered. Conclusion This study highlights the necessity of not considering photoageing as an accelerated intrinsic ageing, but as a distinct physiological process.