Psychological stress signaling affects skin via corticotropin releasing hormone (CRH) release. Through receptor CRH-R1, CRH activates inflammation mediators like NF-kB, IL1-β, IL6 and TNF-α in keratinocytes. Inflammation increases skin redness and leads to extracellular matrix degradation, reduced elasticity / firmness, and wrinkling. We show mitigation of these effects with an aqueous extract of Cistus creticus, a Mediterranean shrub traditionally used as an anti-inflammatory and against some skin diseases. It contains the flavonoid myricitrin, tied to reduced NF-kB, IL6, and TNF-α – suggesting a link to the extract's effects. CRH-R1 receptor blocking was tested in a functional receptor assay in recombinant CHO cells. An ex-vivo model measured master inflammation regulator NF-kB under CRH stimulation (innumohistochemistry). A human keratinocyte culture model under CRH stimulation measured downstream inflammation markers IL1-β, IL6, and TNF-α by ELISA. Finally, a double-blind, placebo-controlled clinical trial, on a highly stressed population, evaluated anti-inflammatory effects (microcirculation; redness; red spots; response to SLS chemical insult) and anti-aging effects (wrinkling). The extract effectively blocked CRH-R1, indicating an interruption of neurogenic inflammation signaling. In the ex-vivo model, the extract blocked the effects of CRH and decreased NF-kB. In the keratinocyte culture, the extract decreased expression of IL1-β, IL6, and TNF-α, negating the effects of CRH. The clinical trial showed significant anti-inflammatory effects (reduced microcirculation; increased resilience to SLS, faster recovery; reduced skin redness) and reduced wrinkling. These show that the extract mitigates neurogenic stress effects on skin by interrupting the stress signaling cascade at CRH-R1, and its value for skin care applications.

The microbiota present on the skin, and its balance between beneficial and detrimental species, are increasingly recognized to play a key role in skin health and beauty, influencing skin moisture, barrier function, radiance, and luminescence. In healthy skin, the balance is tipped towards beneficial bacterial strains, limiting the growth of detrimental strains – contributing to radiant and well-hydrated skin. Prebiotic compositions can support the growth of beneficial bacteria, allowing them to outcompete detrimental bacteria. Dragon fruit (Hylocereus undatus) is a superfruit, rich in polysaccharides demonstrated to have prebiotic effects on gut bacteria. We showed in an in-tubo competitive coculture that Hylocereus undatus fruit extract can support the growth of beneficial bacteria S. epidermidis and S. hominis, while limiting the growth of detrimental bacteria S. aureus and C. acnes. In the present study, this Hylocereus undatus fruit extract was tested in a double-blind, placebo-controlled clinical trial on two groups of 30 volunteers. The results show the beneficial effects of this extract on the skin microbiota balance, as evaluated by 16S rDNA sequencing. The downstream effect on skin sensitivity / resilience was also evaluated (via separate challenges with histamine and SLS). These data were completed by a separate placebo-controlled clinical study conducted on 26 volunteers. In this study, imaging under UV light (Visia) showed that the Hylocereus undatus fruit extract significantly reduced the appearance of porphyrins, hinting at a limiting effect on C. acnes growth, and delivered improvements in skin radiance (evaluated by colorimetric evaluation) and skin barrier function (by TEWL measurement). The above results indicate that a hylocereus undatus fruit extract positively influences the skin's microbiota balance, and thereby delivers significant skin health and beauty benefits.

Acne is one of the most common skin diseases worldwide, affecting up to 85% of the population. At the pathophysiological level, two factors play a crucial role: the sebaceous gland and Cutibacterium acnes (C. acnes). New genomic analysis tools have shown that C. acnes, former P. acnes, a major member of the normal skin microbiota was subdivided into heterogeneous species including acneic bacteria such as RT4, RT5 strains, and commensal bacteria such as the RT6 strain. Moreover, recent data indicated also that the loss of diversity of C. acnes species is associated with acne severity. Taking all this information, we have developed a green polylysine dendrigaft, the Dendrimer (G2), able to rebalance acneic and non acneic stains of C. acnes to protect skin from inflammation, imperfections and acne. In vitro studies revealed the capacity of the G2 to increase membrane fluidity of acneic strains RT4 and RT5 and decrease their biomass in contrast to the RT6 strain. Moreover, G2 showed also a strong anti-adhesion power of C. acnes on human keratinocytes. Ex vivo studies indicated also an anti-inflammatory effect by decreasing IL1α and TLR2 expressions. These data were confirmed in vivo: the study was conducted during 28 days on hemi-face, with a twice daily application of G2 (2 ppm) or Placebo cream on 23 volunteers. After 28 days, we observed a significant decrease of the sebo-regulating effect by 11%, retentional and inflammatory lesions by 31% and 63%, respectively. Interestingly, G2 application promoted also the diversity of C. acnes by increasing the expression of its no acneic strains compared to its acneic strains. To conclude, we have demonstrated that G2 could be the new skin care ingredient able to balance acneic and non acneic strains of C. acnes to improve skin microbiota and protect skin from inflammation, imperfections and acne.

S | Innate Immunity, Microbiology, and Microbiome 350 Histone demethylase LSD1 is required for LC embryonic development but dispensable for LC maintenance and repopulation X Wang, Y Yao, Y Wang, L Zhou and Q Mi Center for Cutaneous Biology and Immunology Research, Department of Dermatology, Henry Ford Health System, Detroit, Michigan, United States Langerhans cells (LCs), the sole dendritic cell subpopulation in the epidermis, are potent regulators of immune surveillance and tolerance. Unlike conventional DCs, LCs follow unique patterns of development and maintenance under steady and inflamed states. Lysinespecific demethylase 1 (LSD1), known to mediate the demethylation of lysine amino acids on histone proteins, plays a key role in the maintenance and differentiation of hematopoietic stem cells. However, the role of LSD1 in LC ontogeny and homeostasis remains unknown. To address this, we generated Csf1rLSD1 conditional knockout (Csf1r.LSD1-KO) mice in which LSD1 was deficient in macrophage/monocytes and LC precursors from embryonic stage. We found a robust reduction of LC precursors in Csf1r.LSD1-KO mice at embryonic day 18.5 and postnatal day 0, suggesting that LSD1 is required for LC ontogeny at late embryonic stage. To investigate whether LSD1 is involved in LC maintenance and repopulation, we created CD11cLSD1 conditional knockout (CD11c.LSD1-KO) mice in which LSD1 was deficient in all DC populations including epidermal LCs after birth. Flow cytometry and immunofluorescent staining of skin showed that the frequency and number of LCs were unaltered in 2-week-old and adult CD11c.LSD1-KO mice compared to wild-type mice. Using an ultraviolet C (UVC)-induced skin damage model, we found that long-term LCs were able to repopulate to the inflamed epidermis of CD11c.LSD1-KO mice 2 weeks after UVC treatment. Overall, our data suggests that LSD1 is critical for LC embryonic development, but not required for the LC maintenance at steady state and repopulation under inflammatory conditions. S44 Journal of Investigative Dermatology (2020), Volume 140 351 Innate lymphoid cells in the blood of untreated and dupilumab-treated patients with atopic dermatitis W Bauer, N Alkon, C Bangert, PM Brunner and G Stingl Department of Dermatology, Medical University of Vienna, Vienna, Austria To investigate the driving force behind the increase of innate lymphoid cells (ILCs) in atopic dermatitis (AD) skin, we numerically and phenotypically compared ILC populations in the blood of untreated AD patients (AD-U), long term ( 16 weeks) dupilumab-treated AD patients (AD-D) and healthy controls (HC). PBMCs were isolated from clinically active AD patients (median age: 32.2 years; n1⁄49), dupilumab-treated AD patients (median age: 33.3 years; n1⁄46) and healthy individuals (median age:28.3 years; n1⁄410), immunostained with a panel of subset-characterising antibodies and analysed with a BD FACSAria III sorter. Total ILCs were defined as viable CD45CD3LinCD127CD161cells and expressed as percent of CD45cells (median). Subpopulations of total ILCs were defined as follows: ILC1 (CD117, CRTH2), ILC2 (CRTH2), and ILC3 (CD117, CRTH2). Results obtained show that the amount of total ILCs among PBMCs is significantly lower in AD patients than in healthy individuals(AD-U: 0.009, HC: 0.049(p1⁄40.001)). This reduction was particularly prominent in the ILC2 subset(ILC2: AD-U: 41.88, HC: 68.20 (p1⁄40.0279)). By contrast, ILC3 were significantly increased in AD patients as compared to HC (ILC3: HC: 18.88, AD-U: 39.23 (p 1⁄4 0.0435)). ILC1 occurred at a comparable frequency in both populations. Interestingly, continued dupilumab treatment led to an increase of ILCs to levels similar to those in healthy persons (AD-U: 0.009, AD-D: 0.037 (p1⁄40.036)). Furthermore, the distribution of the individual ILC subsets in dupilumab-treated patients was similar to that seen in untreated patients. In additional experiments we searched for the presence of skin-homing molecules on ILCs in HC and AD patients and found CCR10>CCR6 CCR4>CLA to be present on substantial portions of ILCs. Our data support the concept that the reported increase of ILCs, particularly ILC2, in AD skin is at least partly due to emigration from blood and that this pathogenic loop could be a potential pharmacologic target. 352 IL-34 differentiation of immunosuppressive macrophage K Kelly-Scumpia, R Shirazi and RL Modlin Medicine/Dermatology, UCLA, Los Angeles, California, United States Myeloid cells from bone marrow are necessary to mount effective immune responses to infectious organisms in the skin. These cells enter the skin and respond to local factors that control their differentiation into specific effector myeloid cells, such as dendritic cells and macrophages (MF). The local and systemic factors responsible for these phenomena are poorly understood. Leprosy provides an ideal human model to study myeloid cells in the skin as exposure of patients to the same pathogen, Mycobacterium leprae, results in distinct disease manifestations. In self-limited, tuberculoid leprosy (T-lep), appropriate monocyte activation results in their differentiation into effector M1 MF and dendritic cells (DCs) that produce antimicrobial peptides and controlM. leprae. In progressive, lepromatous leprosy (Llep), the host develops an inadequate immune response, and fail to clear M. leprae. We previously found that interleukin (IL)-15 and IL-10 are key cytokines promoting effector M1 MF in T-lep and immunosuppressive M2 MF in L-lep patients, respectively. Whether other immunologic factors affect MF differentiation in the context of leprosy has not been fully investigated. Herein, we find a regulatory role of IL-34, a hematopoietic factor that activates c-fms and drives M2 MF development in vitro, as being increased in L-lep skin lesions. Differentiation of monocytes derived MF (MDM) with IL-34 results in increased IL-10 production upon M.leprae stimulation when compared to traditional M-CSF derived MDM or IL15 derived MDM. Similar to IL-10 derived MF IL-34 derived MF demonstrated increased phagocytic activity, but surprisingly, were able to activate a vitamin D dependent antimicrobial response similar to IL-15 derived MF. These data indicate that IL-34 drives an alternative pathway of M2 MF development, whereby they can produce anti-inflammatory cytokines, but retain the ability to induce antimicrobial responses. These findings raise the potential of IL-34 or IL-34 derived MF to treat inflammatory skin disorders while retaining the ability to fight infection. 353 A polylysine dendrigraft able to balance acneic and non acneic strains of Cutibacterium acnes to prevent acne and skin imperfections J Attia, M Borel, M Barreau, E Le Toquin, O Lesouhaitier and E Loing 1 R&D, Lucas Meyer Cosmetics, Toulouse, France, 2 Marketing, Lucas Meyer Cosmetics, Champlan, Croatia, 3 Laboratoire de Mibrobiologie Signaux et Microenvironnement, Evreux, France and 4 N2S, Evreux, France Acne is one of the most common skin diseases worldwide, affecting up to 85% of the population. At the pathophysiological level, two factors play a crucial role: the sebaceous gland and Cutibacterium acnes (C. acnes). New genomic analysis tools have shown that C. acnes, former P. acnes, a major member of the normal skin microbiota was subdivided into heterogeneous species including acneic bacteria such as RT4, RT5 strains, and commensal bacteria such as the RT6 strain. Moreover, recent data indicated also that the loss of diversity of C. acnes species is associated with acne severity. Taking all this information, we have developed a green polylysine dendrigaft, the Dendrimer (G2), able to rebalance acneic and non acneic stains of C. acnes to protect skin from inflammation, imperfections and acne. In vitro studies revealed the capacity of the G2 to increase membrane fluidity of acneic strains RT4 and RT5 and decrease their biomass in contrast to the RT6 strain. Moreover, G2 showed also a strong anti-adhesion power of C. acnes on human keratinocytes. Ex vivo studies indicated also an anti-inflammatory effect by decreasing IL1a and TLR2 expressions. These data were confirmed in vivo: the study was conducted during 28 days on hemi-face, with a twice daily application of G2 (2 ppm) or Placebo cream on 23 volunteers. After 28 days, we observed a significant decrease of the sebo-regulating effect by 11%, retentional and inflammatory lesions by 31% and 63%, respectively. Interestingly, G2 application promoted also the diversity of C. acnes by increasing the expression of its no acneic strains compared to its acneic strains. To conclude, we have demonstrated that G2 could be the new skin care ingredient able to balance acneic and non acneic strains of C. acnes to improve skin microbiota and protect skin from inflammation, imperfections and acne. 354 Innate lymphoid cells in healthy and atopic skin N Alkon, W Bauer, C Bangert, C Staud, T Krausgruber, C Bock, PM Brunner and G Stingl 1 Department of Dermatology, Medical University of Vienna, Vienna, Austria, 2 Department of Surgery, Division of Plastic & Reconstructive Surgery, Medical University of Vienna, Vienna, Austria and 3 Center for Molecular Medicine, Vienna, Austria Atopic dermatitis (AD) is a type 2 inflammatory skin disease with an abundant contribution of Th2 cells. In the recent past it became clear that the skin, under both physiologic and pathologic conditions, contains additional lymphocyte populations. In this context, attention has focused on Innate Lymphoid Cells (ILCs) which, as has been shown by us and others, are present in very small numbers in normal, but in sizable amounts in AD skin. To investigate the differences between ILCs in NHS and AD skin, we performed 10x Genomics single-cell RNA sequencing (scRNA-seq) of samples enriched for ILCs from 3 NHS and 4 AD lesions. For this purpose, CD45CD3Lin cells (including NK-cells) were FACS-sorted from enzymatically digested NHS sheets (z10x10 cm) or 5 mm pun

Olfactory receptors (ORs) are mainly expressed in the nasal olfactory epithelium but can also be found in different cell types throughout the body to regulate physiological cell functions beyond olfaction. Recently, ORs have been detected to be functionally expressed in the skin when activated with odorants. Olfaction is known to be disturbed under stress condition and is widely used in aromachology to afford relaxing effect. Therefore, we questioned the role of skin olfactory receptors in response to this environmental factor. For the first time, we showed the presence of OR10A6, OR2AG2 and OR11H4 in human primary keratinocytes cells and on human skin.n ex-vivo skin model stressed with high levels of epinephrine, a stress hormone, during 9 days was developed. In addition to an acceleration of the cell activity and perturbation of DNA repair with a significant increase of Loricrin, G6pDH and gH2AX of respectively +132%, +27% and +71% (p<0.05), we observed by qPCR and immunofluorescence a decrease of the expression of the 3 ORs (p<0.001) compared to control. Identification of phenylethyl alcohol (PEA) and a PEA-rich rose extract as an agonist of these receptors was realized on cloned ORs. These agonists allowed to protect the skin against the impact of stress but also to restore ORs level of expression, especially for OR2AG2. Overall, these finding suggest that OR10A6, OR2AG2 and OR11H4 are involved into stress response mechanisms and demonstrate that olfactory receptors activation may serve as a new target to fight skin stress.

Somatic mammalian cells enter cellular senescence after a finite number of cell divisions. Senescent cells are characterized by their inability to proliferate and the secretion of promoters of inflammation and tissue deterioration. Telomere shortening is a main underlying mechanism of replicative senescence – the molecular clock counting down towards a programmed limit on cell replications, ending in senescence. This contributes to intrinsic tissue aging, leading to dryness, wrinkling, loss of elasticity, weakened barrier function, and hyperpigmentation. The bulb of Narcissus tazetta is a storage organ enabling the plant to survive adverse conditions through dormancy. When dormant, the plant produces reversible dormancy-inducing cell proliferation inhibitors ("dormins").IFF/Lucas Meyer Cosmetics presents a natural aqueous extract of dormant Narcissus tazetta bulbs, capturing the plant dormancy concept for skin anti-aging. In vitro, treating a culture of aged human dermal fibroblasts with the extract showed: Restrained cell proliferation (by over 40%, from 0.01% extract); Telomere length preservation, significantly increasing telomere length in the aged cells; Significantly reduced activation of the mechanistic target of rapamycin (mTOR) signaling pathway, a central regulator of cellular senescence closely related to the DNA damage response, with influence on longevity and aging; Improved cellular function, significantly enhancing procollagen-1 production in aged cells. In a 28-day double-blind, placebo-controlled clinical study with 1% Narcissus tazetta bulb extract in formulation, the active significantly (p<0.05) improved key skin aging parameters, including: Wrinkles and lines (fine lines, wrinkle counts, wrinkle volumes); Skin elasticity; Skin pigmentation; and Skin barrier function (TEWL). These results demonstrate the value of Narcissus tazetta bulb extract as an anti-aging active ingredient through delayed cellular senescence.

Catecholamines (epinephrine and norepinephrine), the main components of the "fight or flight response", are released under stress. Very useful to escape acute stress, it could alter the immune and inflammatory functions and act negatively in case of chronic exposure (fast-pace life, pollution, climate factors..). The skin also holds a peripheral catecholamine system where epinephrine is synthetized by keratinocytes while the adrenergic receptors are present in both epidermal keratinocytes and melanocytes. To better understand the effect of chronic stress on skin, we developed an ex-vivo skin model on which we applied high levels of epinephrine during 9 days. We showed that epidermis was the most impacted by epinephrine treatment (cell differentiation and metabolism, DNA damage, immune factors…): we observed a significant increase of Loricrin, G6pDH and gH2AX in the epidermis by +132%, +27% and +71% respectively after exposure to high levels of epinephrine, showing an acceleration of the cell activity and perturbation of DNA repair. A specific Rose extract containing the totality of Rose olfactive compounds (hydrophylic and lipophilic ones) has been applied at 1% on the same stress-induced ex-vivomodel, showing a regulation of the cell differentiation and metabolism. In addition, the Rose extract protected the cells against DNA damages. Rose oil (Rosa damascena Mill., Rosaceae) is well known in aromachology for its soothing effect on the emotions, in particular stress-related emotions. It's quite interesting to see that these Rose olfactive compounds could also protect the skin against the stress-related damages. A stressful life but also air pollution up stress hormones, leading to a premature exhaustion of the skin, miming a continuous headlong fight induced by the catecholamines. Protect our skin metabolism and our DNA repair system seems more and more important looking at the society dynamic changes of the last decades.

Effective moisture retention and a radiant and luminescent skin tone are key markers of healthy and beautiful skin. In recent years, accumulating data has suggested that the microbiome present on the skin can play a key role in providing these benefits to the skin. In particular, the balance between the beneficial and detrimental bacteria. In healthy skin, the balance is tipped

Aging, exposure to sun, hormonal abnormalities and various skin disorders increase the deposition of melanin pigment in skin, resulting in dark spots and uneven skin tone. These imperfections are both considered unattractive in many social contexts. For those who are interested in eliminating the presence of dark spots on the skin or achieve a lighter and even skin tone, whitening or bleaching compositions are useful. Many skin-bleaching compositions contain either harsh chemicals with severe skin effects or less stringent actives with questionable stability and efficacy. Colorless carotenoids, phytoene and phytofluene, present a natural, efficient and safe alternative skin whitening agents. We have previously demonstrated in a clinical study that topical application of cream containing 5% tomato colorless carotenoids (IBR-TCLC®) resulted in a significant skin lightening and reduction of dark spots count. These effects were attributed to both their physico-chemical properties (absorption of UV light and singlet oxygen quenching) and biological properties (anti-inflammatory and melanin synthesis inhibition). However, the exact molecular mechanism of action was unclear. Here we report, for the first time, a novel multifunctional mechanism of action. Targeted analysis of Melanogenesis-related gene expression (64-gene array) in human keratinocytes-melanocytes co-culture treated with 0.25% IBR-TCLC® reveal significant alterations in the expression of six key genes, all indicating an outcome of skin lightening. Highlighting effects on keratinocytes-melanocytes proliferation patterns, increased anti-oxidative and anti-inflammatory cellular capacity, affected keratinocytes-melanocytes cross talk resulting in potential decrease in tryrosinase expression and activity. These results shed light on the molecular mechanisms for the documented skin lightening effects of phytoene- and phytofluene-rich extracts, expanding the knowledge on biological function of these natural unique carotenoids.

Olfactory receptors (ORs) are members of G protein-coupled receptor (GPCR) family and form the largest known gene superfamily in the human genome. These receptors are well known for interacting with volatile odorant molecules to lead to the initial perception of smell. Even though a large number of ORs were first described to be expressed in the nasal epithelium, ectopic expression has also been detected in non-olfactory organs, including skin. Indeed, since OR2AT4 was showed to be expressed in the human epidermis [Busse et al., 2014], these receptors have gained a growing interest for their role on skin cells. This receptor activation with Sandalore was showed to be involved in human keratinocyte re-epithelialization during wound-healing processes. However, the impact of odorant molecules on skin as well as the biological role and the involvement of ORs remained unclear. Herein, we looked at whether an olfactory receptor could play a role. Thus, the level of expression of OR2AT4 was studied at the mRNA and protein level on primary human skin cells. The effect of some volatile compounds, described to bind this receptor, was also explored. Genomic studies, cell proliferation, anti-inflammatory effect as well as an in vitro scratch assay were performed. Our results clearly showed a skin effect of volatiles compounds in addition to prove the presence of the receptor. Therefore, our works altogether supports the potential role of odorants molecules on skin through the olfactory receptor activation.

Wrinkles are characterized by deterioration of the dermal fiber network due to a decreased expression of extracellular matrix proteins and their disorganization. Tenascin-X, a matrix glycoprotein, is known to regulate the structure and stability of elastic fibers and the organization of collagen fibrils in the extra-cellular matrix (ECM), influencing cellular rigidity and elasticity. Therefore, the impact of the modulating tenascin-X expression in the skin is of great interest. To counteract these processes, we have developed a natural Australian plant extract of Anigozanthos Flavidus flower (AF), enabling the regeneration in vitro and in vivo the expression, organization and the functionality of the ECM proteins implicated in the tensor effect on skin aging. In vitro studies revealed the capacity of the AF extract to increase type I collagen, tenascin- X and elastin by 136, 39 and 43%, respectively. Moreover the Glassboxplus® model with equivalent dermis indicated that the extract increased significantly contractile forces of wrinkles fibroblasts by 10 and 19% after 6h and 24h of treatment, respectively. These data were confirmed in vivo: the study was conducted during 28 days with a twice daily application of AF cream at 2% on 42 women volunteers. One hour after the first application we observed a decrease by 5% of wrinkle depth as well as an improvement of the neck sagging by 24%. These effects were sustained for28 days as we improved the total anti-wrinkle effect by 10%. In conclusion, we have demonstrated that AF extract regenerates ECM by increasing matrix essential protein expression, organization and functionality. Anigozanthos Flavidus flower extract could be the new innovative skin care ingredient able to promote fast and long lasting tensor effect to counteract skin aging.

Acute exposure to UV radiations results in erythema, immune suppression and cell death, while chronic exposure results in photoaging and carcinogenesis. In order to fight UV-induced skin damages, we have developed an oil-soluble form of an α-MSH biomimetic peptide. The binding of α-MSH to its melanocortin-1 receptor (MC1-R) induces epidermal pigmentation, which in turn activates the signal transduction pathway leading to the induction of melanin synthesis. In addition, it has been proven that α-MSH directly reduces UV-induced DNA damage and enhances DNA repair in epidermal melanocytes and keratinocytes, by modulating the function of DNA repair molecules. The objective of this study was to investigate whether a biomimetic peptide analogue of α-MSH, acetyl hexapeptide-1, was able to stimulate the natural skin defense system against sun exposure. We demonstrated in vitro that acetyl hexapeptide-1, acts effectively and simultaneously on melanogenesis to improve natural cell UV protection by melanin, on DNA protection (Comet assay, reduction in 8-oxo-dG) and repair (decrease in sunburn cells, caspase-3 activity and pyrimidine dimers) to limit photoaging and on the inflammatory cascade to soothe sun-ravaged skin (IL-1α, IL-8, PGE2 ). Clinically this biomimetic peptide demonstrated its efficacy on the increase in skin pigmentation and anti-erythemal properties after 14 days skin application showing a significant increase (+20%) of the Minimal Erythemal Dose compared to placebo. Furthermore, we developed a smart lipophilization technology (transparent w/o microemulsion) in order to improve the peptide diffusion through the Stratum corneum and allow its introduction in clear oil-based products.Especially designed to be introduced in oil-based products, this peptide represents the biological solution to improve sun care and anti-aging product efficacy in order to limit sun-induced premature aging.

Objective Hair greying (i.e., canities) is a component of chronological ageing and occurs regardless of gender or ethnicity. Canities is directly linked to the loss of melanin and increase in oxidative stress in the hair follicle and shaft. To promote hair pigmentation and reduce the hair greying process, an agonist of -melanocyte-stimulating hormone (-MSH), a biomimetic peptide (palmitoyl tetrapeptide-20; PTP20) was developed. The aim of this study was to describe the effects of the designed peptide on hair greying. MethodsResultsEffect of the PTP20 on the enzymatic activity of catalase and the production of H2O2 by Human Follicle Dermal Papilla Cells (HFDPC) was evaluated. Influence of PTP20 on the expression of melanocortin receptor-1 (MC1-R) and the production of melanin were investigated. Enzymatic activity of sirtuin 1 (SIRT1) after treatment with PTP20 was also determined. Ex vivo studies using human micro-dissected hairs allowed to visualize the effect of PTP20 on the expression in hair follicle of catalase, TRP-1, TRP-2, Melan-A, ASIP, and MC1-R. These investigations were completed by a clinical study on 15 human male volunteers suffering from premature canities. The in vitro and ex vivo studies revealed the capacity of the examined PTP20 peptide to enhance the expression of catalase and to decrease (30%) the intracellular level of H2O2. Moreover, PTP20 was shown to activate in vitro and ex vivo the melanogenesis process. In fact, an increase in the production of melanin was shown to be correlated with elevated expression of MC1-R, TRP-1, and Melan-A, and with the reduction in ASIP expression. A modulation on TRP-2 was also observed. The pivotal role of MC1-R was confirmed on protein expression analysed on volunteer's plucked hairs after 3 months of the daily application of lotion containing 10 ppm of PTP20 peptide. ConclusionResumeThe current findings demonstrate the ability of the biomimetic PTP20 peptide to preserve the function of follicular melanocytes. The present results suggest potential cosmetic application of this newly designed agonist of -MSH to promote hair pigmentation and thus, reduce the hair greying process. ObjectifMethodesLe blanchiment des cheveux (i.e., canitie) est un element du vieillissement chronologique qui se produit independamment du genre ou de l'ethnie. La canitie est directement liee a la perte de melanine et a l'augmentation du stress oxydatif dans le follicule et la tige pilaires. Pour favoriser la pigmentation des cheveux et reduire le processus de blanchiment des cheveux, un agoniste de l'<< -melanocyte-stimulating hormone >> (-MSH), un peptide biomimetique (<< palmitoyl tetrapeptide-20 >>; PTP20) a ete developpe. Le but de cette etude est de decrire les effets de ce peptide concu, sur le blanchiment des cheveux. L'effet du PTP20 a ete evalue sur l'activite enzymatique de la catalase et la production de H2O2 par les cellules humaines de la papille dermique du follicule pileux (<< Human Follicle Dermal Papilla Cells >>, HFDPC). L'influence du PTP20 sur l'expression du recepteur a la melanocortine (<< melanocortin receptor-1 >>, MC1-R) et sur la production de melanine ont ete etudies. L'activite enzymatique de la sirtuine 1 (SIRT1), apres traitement avec PTP20, a aussi ete determinee. Des etudes ex vivo sur cheveux humains microdisseques ont permis de visualiser l'effet du PTP20 sur l'expression de la catalase, TRP-1, TRP-2, Melan-A, ASIP et MC1-R, dans le follicule pileux. Ces etudes ont ete completees par un essai clinique incluant 15 volontaires masculins souffrant de canitie precoce. ResultatsConclusionLes etudes in vitro et ex vivo ont revele la capacite du peptide PTP20 examine, a augmenter l'expression de la catalase et a diminuer (30%) le niveau intracellulaire de H2O2. De plus, il a ete montre que PTP20 activait le processus de melanogenese in vitro et ex vivo. En fait, il a ete montre qu'une augmentation de la production de melanine etait correlee avec une expression plus elevee de MC1-R, TRP-1 et Melan-A, ainsi qu'avec une reduction de l'expression d'ASIP. Une modulation de TRP-2 a aussi ete observee. Le role cle de MC1-R a ete confirme apres analyse d'expressions proteiques, sur les cheveux epiles des volontaires, apres 3 mois d'application quotidienne d'une lotion contenant 10 ppm du peptide PTP20. Les conclusions actuelles demontrent la capacite du peptide biomimetique PTP20 a preserver la fonction des melanocytes folliculaires. Les resultats presentes suggerent une potentielle application cosmetique de cet agoniste d' -MSH nouvellement concu, pour favoriser la pigmentation et par consequent, reduire le processus de blanchiment des cheveux.

Premature canitie and greying hair pigmentation are phenomenons directly linked to a melanin lack in the hair bulb but also to the accumulation of hydrogen peroxide (H2O2) in hair follicles. To counteract these processes, we have developed a biomimetic peptide of the α-MSH (palmitoyl tetrapeptide-20), enables to promote in vitro, ex vivo and in vivo hair pigmentation and reduce hair greying process. In vitro studies revealed the peptide capacity to increase melanin synthesis by 39% in human melanocytes and melanosome transfer to keratinocytes by 50%. In HFDP cells, the peptide was also able to decrease significantly by 30% intracellular H2O2 level. Ex vivo, after 7 days of peptide application, the peptide increased by 35% the hair bulb pigmentation. This result was confirmed by immunohistochemistry and fluorescent immunostaining of pigmentation and oxidative markers on human micro dissected hairs. Protein expressions of Melan-A, TRP1, TRP2 were increased whereas the expression of ASIP protein and catalase was decreased. The clinical study conducted during 3 months with a daily application of a peptide lotion at 2% on fifteen men volunteers suffering from canitie showed a significant decrease in L factor by 5.3. Interestingly, this result was also confirmed by gene and protein expressions directly analyzed on volunteers hair. In summary, we have proven that our palmitoyl tetrapeptide-20 fights against hair greying, protects follicular melanocytes activity and could be the new hair care innovative peptide able to promote hair pigmentation and counteract the greying hair process.

Stratum corneum (SC) has to be impermeable to protect our body from external aggression and also excessive water loss. Nevertheless, to be efficient, cosmetic active ingredients must cross the SC barrier to achieve the viable cells of epidermis. A vast range of penetration enhancers has been developed following two different mechanisms: Modifying the skin polarity; Interruption of the intercellular lipid packing by delipidation leading to an increase of trans-epidermal water loss and dehydration. Knowing that consumers are increasingly seeking cosmetic products providing better results and rapid efficacy, the challenge of cosmetics industry is to improve the bioavailability of active molecules without destroying the barrier function of the SC and decreasing its hydration. In this way, we developed a phospholipid lamellar system (hydrogenated phospholipids and fatty acids) based on SC chemical and structural biomimicry using polarity modification mechanism. When applied on the skin, hydrogenated phospholipids first fuse with the skin surface forming a non-permeable and occlusive gel linked to the phospholipid organization into lamellar rigid one-dimensional network (Structural biomimicry). Furthermore, fatty acids interact with the intercorneocytar lipid cement of the SC and modify its structure leading to the creation of a water vacuoles facilitating the permeation of hydrophilic molecules through the membrane (chemical biomimicry). Different studies were performed to understand the impact of the phospholipid lamellar system on the integrity of the SC (TEWL, corneometry, electron microscopy, D-squam) and on the active ingredients permeation (bioavailability study). To conclude, the obtained results confirmed that our optimized lipid mixture meet the challenge of improving the bioavailability of active ingredients, by increasing the hydration of the SC and reinforcing its integrity.

Premature canitie and progressive loss of hair pigmentation (graying hair) are phenomena directly linked to a melanin lack in the hair bulb. This lack can be attributed to the decrease level of melanin or its disappearance. Moreover, the latest scientific findings have implicated the role of hydrogen peroxide (H2O2) in graying hair process. To counteract these processes, we have developed a biomimetic peptide (palmitoyl tetrapepitde-20) of the α-MSH, enables to promote in vitro, ex vivo and in vivo hair pigmentation and to reduce the hair graying. In vitro studies revealed the peptide capacity to modulate the expression of melanocortin receptor-1 (MC1-R) in cultured melanocyte and to increase melanin synthesis, 10 fold greater than that of α-MSH. The designed peptide was also able to decrease significantly by 30% the H2O2 intracellular level in HFDPC cells. Moreover, ex vivo investigations evidenced the significant increase of TRP1, MC1-R, Melan-A and TRP2 protein expressions in the peptide treated scalp explants. These data were also confirmed by clinical study conducted during 3 months with daily application of peptide lotion containing 2% of palmitoyl tetrapepitde-20 on fifteen men volunteers suffering from canitie. Chromameter measurements showed that the peptide has decreased the L factor brightness by 5.3%. Interestingly, this result is also confirmed by gene and protein expressions directly analyzed on volunteer's hair. Indeed, oxidative markers and ASIP expression were significantly decreased in favor of MC1-R increasing expression. In summary, we have proven that the palmitoyl tetrapepitde-20 fights against hair graying, protects follicle melanocytes activity and could be the new hair care innovative peptide able to promote hair pigmentation and counteract the graying hair process.

Seborrhea is a common cosmetic issue that occurs when oversized sebaceous glands produce excessive amounts of sebum, giving the appearance of shiny and greasy skin. Sebum is made and secreted by sebaceous glands, via the differentiation and disintegration of fully mature sebocytes, a unique process termed holocrine secretion. Moreover, skin oiliness may vary according to diet, age, hot humid climates and ethnicity. Depending on new researches, ethnicity had no significant impact on level of residual skin surface components derived from sebum but, could affect sebum quality (composition and components oxidation). Convinced by the interest to act on the genesis of the sebum secretion mechanism, we have developed a new sebosuppressive agent able to modulate sebocytes differentiation, and also sebum quality. The natural Australian extract selected has been isolated from Backhousia citriodora (Lemon Myrtle leaf). Conforming its promise, Lemon myrtle extract tested on human sebocytes decrease by 32% Epithelial Membrane Antigen expression (marker of sebocyte differentiation) and so by 30% the lipid accumulation in the cytoplasm. Furthermore, two clinical studies validate Lemon Myrtle efficacy. On one hand, at 15 and 30 days, Lemon Myrtle treatment decreases significantly skin sebum content (-17% and -31% respectively) and thus surface covered by oily spots (-17% and -22% respectively). On the other hand, a sebum lipodimic analysis on ethnic volunteers (Caucasian, Asian and African-American) demonstrates that Lemon Myrtle regulates sebum composition and protects its components from oxidation. This natural extract has proven its efficiency to modulate human sebaceous terminal differentiation, characterized by cell changes, lipid droplets accumulation, nuclear degeneration and excess sebum production. Therefore, Lemon Myrtle extract is a promising sebo-regulator to act at the genesis of sebum production and to regulate sebum quality whatever the ethnicity.

Seborrhea is a common cosmetic issue that occurs when oversized sebaceous glands produce excessive amounts of sebum, giving the appearance of shiny and greasy skin. The balance between sebum secretion and the oxidation of its components (squalene, waxe, fatty acids…) has been described as a protective skin barrier against environmental stimuli (UVa, pollution) and dehydration. Moreover, it was described that diet, age, climates or ethnicity interfere in this natural balance and induce hyper-seborrhea and skin inflammation. Convinced by the interest to rebalance both sebum quantity and quality, we developed Backhousia citriodora leaf extract, a new seboregulator agent effective on multi-ethnicities. In tubo studies revealed the extract capacity to protect the squalene, a sebum component, against the oxidation by 18% and to decrease, in vitro the protein expression of the sebocyte differentiation marker, Epithelial Membrane Antigen, by 32%. The designed extract was also able to significantly decrease by 30% the lipid accumulation in sebocyte culture. These data were confirmed by clinical study conducted during 28 days with two daily applications of cream containing 2% of Backhousia citriodora leaf extract on 43 hyper seborrheic and multi-ethnic volunteers. Sebumeter measurement showed the extract decreased significantly skin sebum quantity by 7% on all ethnicity. Moreover, sebum lipodomic profile analysis revealed the extract decreased squalene and glycerid contents by 15% and 23% on Caucasian, by 11% and 15% on Asian and by 46% and 44% on African-Americans. Finally, the extract permitted to reduce sebum shiny effect on Caucasians (1%), Asians (3.4%) and Africans-Americans (11%). In summary, we have proven that the Backhousia citriodora leaf extract rebalances sebum quality and secretion by acting simultaneously on the oxidation, the composition and the production of sebum, whatever the ethnicity. This extract is a new active solution to fight against oily and shiny skin.

ObjectivesLiposomes are commonly used in cosmetic formulations to increase the bioavailability of active ingredients. We have previously shown that polysaccharide coating of liposomes improves their resistance to surfactants and electrolytes. In the current study, we have assessed the impact of coating on the skin penetration enhancer properties of liposomes.MethodsThe physicochemical properties of coated liposomes (Ionosomes) were evaluated before and after encapsulation of two different hydrophilic molecules (caffeine and a hexapeptide), and compared to those observed with non-coated liposomes. Moreover, in vitro permeation experiments were performed using Franz-modified diffusion cells, with normal human skin as membranes.ResultsResults showed that both coated and non-coated liposomes significantly improved the bioavailability of hydrophilic active molecules in skin, compared to reference solutions. Although liposome coating slightly reduced entrapment efficiency, the delivery of active molecules was not adversely affected by the process. In conclusion, polysaccharide coating of liposomes allows for better protection of their integrity without compromising the skin bioavailability of the active molecules that they convoy.

Rosacea is a common chronic inflammatory skin disease that occurs at any age and characterized by skin inflammation, change of the skin’s connective tissue and dilatation of the blood vessels. Some of these different symptoms are linked to the TLR/NF-κB pathway: interleukins and MMPs productions. Swertiamarin, a secoiridoid glycoside, has been previously studied for its capacity to inhibit NF-κB pathway in arthritis and regulated proinflammatory cytokines and enzymes. Due to this activity, an evaluation of the molecule on Rosacea has been carried out on the different key parameters implied in the disease. In vitro analysis of the activity of swertiamarin has been done on the inflammation parameter, IL-6 release (a proinflammatory cytokine), using immortalized HaCaT human cell line and dosed by Elisa assay. For the matrix issue, the effect of swertiamarin was investigated on fibronectin and versican synthesis with also an in tubo evaluation of MMP-2 activity. Then, a clinical evaluation of the molecule was performed on 25 women aged between 46 and 65 years old for 28 days by using the skin analysis imaging system able to quantify red areas. The inflammation involved in Rosacea skin decreased in vitro, with a reduction by 46% of the IL-6 release, at the concentration of 0.0025% of swertiamarin. Moreover, the same treatment reduced the change of the skin’s connective tissue through the increase of versican synthesis by 67% on normal human dermal fibroblasts. These data were confirmed by clinical study: 0.025% of pure swertiamarin improved the main sign of Rosacea after 28 days of treatment, with a significant decrease of 12% of the skin redness. Swertiamarin is able to increase dermal matrix proteins synthesis, reduce their degradation and decrease the release of cytokines involved in the inflammatory TLR/NF-κB pathway. Swertiamarin has proven to be a good candidate to fight against the symptoms of Rosacea.