The naturally occurring tetrapeptide acetyl-N-Ser-Asp-Lys-Pro (AcSDKP) recognized as a potent angiogenic factor was shown recently to contribute to the repair of cutaneous injuries. In the current article, we report the ability of AcSDKP to exert a beneficial effect on normal healthy skin and scalp and to compensate for the ageing process. In vitro AcSDKP at 10⁻¹¹-10⁻⁷ M significantly stimulates the growth of human keratinocytes, fibroblasts and follicle dermal papilla cells. Moreover, it enhances the growth of human epidermal keratinocyte progenitor and stem cells as shown in a clonogenic survival assay. Topical treatment of ex vivo cultured skin explants with 10⁻⁵ M AcSDKP increases the thickness of the epidermis and upregulates the synthesis of keratins 14 and 19, fibronectin, collagen III and IV as well as the glycoaminoglycans (GAGs). In the ex vivo-cultured hair follicles, AcSDKP promotes hair shaft elongation and induces morphological and molecular modifications matching the criteria of hair growth. Furthermore, AcSDKP at 10⁻¹¹-10⁻⁷ M was shown to improve epidermal barrier, stimulating expression of three protein components of tight junctions (claudin-1, occludin, ZO-1) playing an important role in connecting neighbouring cells. This tetrapeptide exercises also activation of SIRT1 implicated in the control of cell longevity. Indeed, a two-fold increase in the synthesis of SIRT1 by cultured keratinocytes was observed in the presence of 10⁻¹¹-10⁻⁷ M AcSDKP. In conclusion, these findings provide convincing evidence of the regulatory role of AcSDKP in skin and hair physiology and suggest a cosmetic use of this natural tetrapeptide to prevent skin ageing and hair loss and to promote the cutaneous regeneration and hair growth.

The 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 α-MSH to promote hair pigmentation and thus, reduce the hair greying process.

We previously showed that topical application of hexoses such as fructose accelerates stratum corneum barrier recovery after barrier disruption. We also showed that various hexoses and polyols interact with phospholipids and decrease the phase transition temperature from the liquid crystal to the crystal phase; i.e., they stabilize the fluid phase of lipids at low temperature. In the present study, we confirmed that topical application of xylitol aqueous solution on human skin after tape stripping accelerated barrier recovery. We next examined changes of lipid fluidity in an epidermal-equivalent model after the application of water and aqueous solutions of xylitol and fructose. For this purpose, we used Laurdan, an environmentally sensitive fluorescence dye, as an indicator of lipid fluidity and observed its emission spectrum with a two-photon microscope. Application of xylitol and/or fructose aqueous solution increased the lipid fluidity of the stratum granulosum layer compared to water application. These results indicate that topical application of certain hexoses or polyols increases the lipid fluidity at the uppermost layer of the stratum granulosum, accelerates the release of lipid from the stratum granular layer, and improves epidermal barrier homeostasis. 627 Fluctuation of Caspase 14 caused by temperature and humidity unbalances the NMF production pathway and the process of keratinocyte enucleation

Background Purple tulip extract is a rich source of flavonoids which are powerful antioxidants and can hence be considered as an ideal candidate for use in skin care products. Aims We aimed to evaluate the effects of purple tulip extract on skin quality and to determine its molecular modes of interaction. Methods A pangenomic study on human skin fibroblasts was carried out to analyze multiple changes in gene expression. Ex vivo studies of human skin explants exposed to ultraviolet (UV) irradiation or H2O2 were performed to assess modulations of protein expression. Finally, a clinical assay was carried out to evaluate the efficacy of purple tulip extract on skin appearance and condition of aged women. Results Genetic modulation analyses led us to infer the induction of many biological functions including cell differentiation, proliferation, migration, inflammatory responses, and matrix remodeling. The ex vivo studies revealed an enhancement of the collagen network and increased expression of glycosaminoglycans (GAG), fibronectin, and collagen VI. Finally, the clinical study highlighted the potential anti‐aging properties of the purple tulip extract which decreased the relaxation of the oval face and improved skin elasticity after 28 days of treatment. Significant reductions of the length and depth of the nasolabial wrinkles were also observed. Conclusion Our genomics data on the effect of purple tulip extract on the ex vivo UV‐challenged skin showed that genes responsible for, among others, the upkeep of the skin, such as collagen induction, immune cell proliferation, and epidermal repair, were all up‐regulated. More importantly, the clinical study corroborated these data by the visible and measurable effects of the topical purple tulip extract on the aged skin of 22 women, further demonstrating the beneficial impact of the extract on aged skin.

and 4 Univ of Manchester, Manchester, United Kingdom Chemical signals acting on olfactory receptors (OR) regulate many cell functions beyond olfaction, e.g. OR2AT4-mediated keratinocyte (kerat) proliferation and migration in vitro.Here, we asked whether OR2AT4 also plays a role in human hair follicle (hHF) biology. Indeed, anagen scalp hHFs prominently express OR2AT4 protein (IF) in the central outer root sheath, and up-regulate OR2AT4 transcription (qRT-PCR) after stimulation with a specific OR2AT4 agonist, SandaloreÒ. SandaloreÒ significantly retarded spontaneous catagen development in anagen HFs ex vivo and decreased the number of apoptotic (TUNEL + or caspase-3 + ) hair matrix (HM) kerat compared to controls. These effects were partially counteracted by co-administering the specific OR2AT4 antagonist, PheniratÒ. Most importantly, catagen was induced prematurely and HM kerat apoptosis was enhanced in OR2AT4silenced hHFs, compared to vehicle HFs, even under SandaloreÒ stimulation. SandaloreÒ significantly decreased TGFb2 expression, but significantly increased IGF-1. OR2AT4 knockdown decreased IGF-1 expression while TGFb2 expression was unchanged, suggesting that OR2AT4 activation impacts on HF cycling via up-regulating IGF-1. Microarray analysis showed that SandaloreÒ significantly downregulated the transcription of pro-apoptotic and up-regulated anti-apoptotic genes. By phosphokinase assay, phosphorylation of kinases involved in the IGF-1 pathway was enhanced under SandaloreÒ stimulation. In summary, we show for the first time that hHFs engage in OR-mediated chemosensation and that OR2AT4 stimulation is required to maintain hHFs in anagen ex vivo. This suggests that OR2AT4 ligands like SandaloreÒ can be recruited for the management of hHF growth disorders.