Rice (Oryza sativa) bran waxes, the by-products of rice bran oil manufacturing, are widely used as inactive components in several preparations. Nevertheless, the function of rice bran waxes against skin aging has never been reported. This study aimed to investigate thermal property and fatty acid profile of rice bran waxes, including rice bran soft (RBS) and hard (RBH) waxes, and the activities against skin aging in cultured skin cells. Thermal property and fatty acid profile of rice bran waxes were analyzed by differential scanning calorimetry and gas chromatography-mass spectrometry, respectively. The cytotoxicity assay of waxes was performed in B16F10 melanoma cells, human skin fibroblasts, and co-culture cells of HaCaT cells and human skin fibroblasts. The non-cytotoxic concentrations of waxes were evaluated for their activities against skin aging, including melanogenesis assay, antioxidant activity, collagen content analysis, matrix metalloproteinase-1 and matrix metalloproteinase-2 inhibitory assay, and anti-inflammatory activity. Thermal property indicated the endotherm peaks with melting temperatures at 40.89 ± 0.27°C and 69.64 ± 0.34°C for RBS and RBH, respectively. The main fatty acids in RBS were oleic (31.68 ± 0.75%) and linoleic acids (27.19 ± 0.40%), whereas those in RBH were palmitic (36.24 ± 1.08%) and stearic acids (35.21 ± 4.51%). The cytotoxicity assay in single cells and co-culture cells showed the non-cytotoxicity of RBS (0.0001 - 1 mg/mL) and RBH (0.0001 - 0.1 mg/mL). The anti-skin aging activities of 1 mg/mL RBS and 0.1 mg/mL RBH included the melanogenesis inhibition by suppression of tyrosinase and tyrosinase-related protein-2 enzymes, the antioxidant activity by cellular protection against cell damage and cell death, the collagen stimulation, the matrix metalloproteinase-1 and matrix metalloproteinase-2 suppression, and the anti-inflammation. The study results suggest that RBS and RBH can potentially be applied as the functional ingredients in formulations against skin aging as well as provide the superior benefit on skin moisturization.

As every skin type worldwide is concerned by photoprotection, with consumers preferring cosmetic elegant and efficient sunscreen products, we aim at developing the most performant and desirable suncare products. We selected an interesting polymer, abbreviated AAHCP and designed CryoSEM, Small Angle & Wide Angle X-ray Scattering and Confocal Laser Scanning Microscopy studies to understand it's behavior in solution and in simplex sun care formulations. This allowed us to develop innovative sunscreen formulation technology that was demonstrated by in-vitro and in-vivo photoprotection methods. Comprehensive photoprotection evaluations were made on the fully developed sun protection product. We observed the polymer oil structuring properties as well as its ability to form small and stable droplets in simplex emulsions. In-vitro and in-vivo Sun Protection Factor (SPF) measurements demonstrated the sun protection boosting efficacy of AAHCP polymer in several emulsions or as a stand-alone emulsifier. This formulation technology also allowed to filtering system concentration optimization. Use-test performed on a fully developed AAHCP-based sunscreen validated its optimal performances as well as its ideal cosmetic features, with non-sticky, non-greasy perception, and invisible skin result. For the first time, thanks to a new specific polymer creating a new type of emulsion, we succeed in reconciliate in a single sun care product maximal SPF efficacy, resistance to numerous stresses and optimal sensoriality.

This study aimed to assess the effect of 1,3-propanediol at different concentrations (5%, 10%, or 15%), either applied alone or in combination with butylene glycol (5%) and/or glycerol (5%), on skin hydration and skin barrier function. The measurements were conducted using capacitance to determine skin hydration and trans epidermal water loss (TEWL) rates to evaluate skin barrier function. A total of 30 healthy female subjects participated in the study. Capacitance and TEWL measurements were conducted at multiple time points, including before application and at 15 minutes, 2 hours, and 8 hours after the humectants were applied to the forearms of the subjects. All subjects provided written informed consent. The 1,3-propanediol in all concentrations and in all combinations (with butylene glycol and/or glycerol) increased skin hydration and improved skin barrier function 15 minutes, 2 hours, and 8 hours after application. Glycerol increased the hydration performance of 1,3-propanediol. The application of 1,3-propanediol at a concentration of 15%, either alone or in combination with other humectants, reduced the TEWL to a greater extent than lower concentrations of 1,3-propanediol. Furthermore the addition of glycerol to 1,3-propanediol 15% improved the skin barrier and reduced TEWL when compared with 1,3-propanediol alone and with the combination of1,3-propanediol + butylene glycol. The humectants significantly improved skin hydration and reduced TEWL throughout the 8-hour time course. The increase in 1,3-propanediol concentration, as well as its combination with glycerol, provided a greater benefit to the skin, improving both hydration and the skin barrier function.

Ultraviolet radiation (UVR) is a known environmental key factor for premature skin aging. Only few scientific evidence is available to support the effects of UVR on the skin microbiome. This in vivo pilot study aimed to evaluate the impact on the skin microbiome upon erythemal UV exposure and the protection of UV-exposed skin microbiome by UV filters. Ten female volunteers were treated with an SPF 20 sunscreen and placebo formulation (without UV filters) on their upper middle backs and irradiated with an erythemal dose (2 MED) by a solar simulator. Skin swabbing samples from four zones (i.e., unexposed, exposed, sunscreen- and placebo-treated on exposed skin) were collected for the microbiome analysis before and 2 hours after UV exposure, respectively, and processed via shallow 16S rRNA Amplicon and Shotgun Metagenomic sequencing. An in vitro UV method was developed to confirm the protection of isolated bacterial strains by single UV filters and combinations. Alpha diversity was impacted by significant inter-individual differences and by treatment rather than by irradiation. Cutibacterium acnes was found to be most abundant and a confounding factor for diversity. On a species level Lactobacillus crispatus was negatively associated with UVR and placebo treatment, whereas there was a positive association with the sunscreen treatment. The sunscreen treatment also favored an interaction network with central Micrococcus genus. The in vitro results showed that both single UV filters and combinations had specific effects on the survival rates of L. crispatus, C. acnes, and S. epidermidis. We identified potential microorganisms and bacterial interactions that were associated with an SPF 20 sunscreen treatment. The specific protection of L. crispatus as a key player in the UV-exposed skin microbiome and reduction of C. acnes population by UV filters might lead to new cosmetic concepts for photoprotection.

Skin cancer continues to increase in incidence year-on-year and represents the most common form of cancer across the globe. Every human undergoes premature ageing, particularly on the face, neck and hands. Both phenomena are driven primarily by chronic, daily exposure to solar ultraviolet radiation (UVR). While sunscreen products play a primary role in the prevention of UVR skin damage, the active ingredients, i.e., UVR filters, are facing unprecedented challenges in the coming 10 years and their future is by no means certain. This article, therefore, reviews afresh the facts around photoprotection and the role of sunscreen products in the prevention of acute (sunburn) and chronic (cancer, photoageing) skin damage and compares/contrasts these with various emerging questions and opinions around UVR filter technology. We present a passionate defence of this remarkable technology, but also attempt to imagine a world without it.

The aim of this work was to review the principals of environmental hazard and risk assessment (ERA) of cosmetic UV filters registered under EU REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals). Furthermore, effects as obtained from non-standardized testing methods and organisms from scientific literature were compared against the predicted no effect concentrations (PNECs) as derived based on standardized test methods for the various environmental compartments under REACH. The REACH dossiers at the ECHA webpage were screened for available information related to basic physico-chemical data (i.e. water solubility, octanol-water partitioning coefficient), PNECs and associated data (data basis, assessment factors (AFs)). Scientific literature was screened for available ecotoxicity data and the adverse effect levels were compared against the derived PNECs under REACH. Current approaches for environmental risk assessments of UV filters were evaluated for its applicability for a direct release scenario. Under REACH, PNECs were derived for all hazardous UV filters. Although, PNECs were often derived for various environmental compartments (i.e. freshwater, marine water, sediment, soil), results from literature focused on aquatic data. Effects as observed within scientific literature matches in principle with the hazardous profile of the UV filters. Effects levels both on the acute and the chronic toxicity as retrieved from the non-standardized test organisms (literature) were above the derived PNECs under REACH. Currently, ERAs performed for cosmetic UV filters under REACH are solely tonnage driven and thus do not fully capture the use in sunscreens and associated leisure activities. Existing EU REACH regulation is considered as sufficient to evaluate the environmental safety of UV filters used in sunscreens. To cover the direct release of UV filters due to various leisure activities into the aquatic freshwater and marine environment, an additional application-based ERA is considered necessary.

To develop and evaluate the efficacy of WS Biotin, a novel water soluble- form of D-Biotin, for cosmetic use. A new encapsulated form of D-Biotin was developed for the purpose of improving the water solubility property of biotin. This novel form of encapsulated biotin was characterized for its physicochemical properties- particle size, D-Biotin content and solubility in water. Also, proliferation and gene-expression in vitro tests in cell culture were performed to evaluate its effectiveness in promoting hair growth, ELISA test was conducted for hair keratinization, and skin lightening property was testedby analyzing the intracellular melanin content. The developed WS Biotin microcapsules exhibit a particle size range of 2-30 μm with D-Biotin content of ~50 % (w/w). the water solubility of WS Biotin was found to be 20-fold more than free biotin The obtained In vitro results indicated that WS Biotin enhances the expression of hair-related keratins in hair follicle keratinocytes, as well as the expression of hair growth-promoting genes in dermal papilla cells. Moreover, the melanin content in UVA-exposed epidermal melanocytes was reduced upon exposure to WS Biotin. In this work, a novel form of encapsulated biotin, WS Biotin, was developed in order to improve the water solubility of free biotin and was found to be effective for cosmetic use in both hair and skin applications.

To summarize key research published by the author's group, dealing with skin photoaging and its photoprotection. Two methodologies (standard photographs and selfies imaging) resulting from referential skin ageing atlases were applied on 2487 subjects of different ancestries, ages and gender. These aimed at first to best assess and grade the variable severities of some facial signs (texture/wrinkles, pigmentary spots, sagging and vascular disorders) that occur progressively during the photoaging process. Second, such methodologies were used to record the benefits brought by a photoprotective regimen (671 women and men). In all studied ancestries, each facial sign show an increase severity along decades, at its own pace, some showing a linear like progression, whereas some plateau at early ages. These changes differed according to skin innate colour (phototype) and with individual behaviours vis-à-vis sun exposures, more so among European women than North-East Asian women. An effect of gender (less severe alterations) was observed on Chinese men, as compared to Chinese women. Pigmentary disorders were found hallmarks of photo-aged North-East Asian women. Globally, photoaging impact the apparent age of the different subjects. The counteracting effects of strong topical Photoprotective regimens were evidenced along a 6-month seasonality in Chinese and French women or 1-year period in Brazilian women with phototypes II to VI. Photoprotection led to a more even skin complexion among Indian subjects with pigment irregularities. Two factors clearly hamper a better assessment of the efficiency of photoprotection of the sun-induced cutaneous ageing: short durations (months) of the studies with regard to the global fate of photoaging by decades and the number of studied subjects, limited to hundreds for practical reasons. The methodology based on the automatic analysis of facial signs through selfies images could theoretically bypass both factors, allowing thousands of subjects to be studied along years.

To propose a strategy for using sunscreens that optimizes the balance between skin health and adverse effects to humans and the environment. A model was developed to explore the relationship between sunscreen usage and personal sun exposure throughout the year in populations resident at different latitudes. There is little biological justification in terms of skin health for applying sunscreen over the 4-6 winter months at latitudes of 45° N and higher, whereas year-round sunscreen is advised at latitudes of 30° N and lower. Avoiding sunscreen application at times when it is biologically unnecessary results in an annual reduction in sunscreen use of 25%. Furthermore, using products containing UV filters over the winter months at more northerly latitudes could lead to a higher number of people with vitamin D deficiency. The single largest use of sunscreen is on a sun-seeking holiday and encouragement to make more use of clothing and shade would appreciably reduce the sunscreen burden to the environment. We need to use sunscreens wisely so that we gain the health benefit from their use while at the same time limiting possible harm to ourselves and the environment.