Oxidative stress in hair follicle development and hair growth: Signalling pathways, intervening mechanisms and potential of natural antioxidants.

Hair follicle development and hair growth are regulated by multiple factors and multiple signalling pathways. The hair follicle, as an important skin appendage, is the basis for hair growth, and it has the functions of safeguarding the body, perceiving the environment and regulating body temperature. Hair growth undergoes a regular hair cycle, including anagen, catagen and telogen. A small amount of physiological shedding of hair occurs under normal conditions, always in a dynamic equilibrium. Hair loss occurs when the skin or hair follicles are stimulated by oxidative stress, inflammation or hormonal disorders that disrupt the homeostasis of the hair follicles. Numerous researches have indicated that oxidative stress is an important factor causing hair loss. Here, we summarize the signalling pathways and intervention mechanisms by which oxidative stress affects hair follicle development and hair growth, discuss existing treatments for hair loss via the antioxidant pathway and provide our own insights. In addition, we collate antioxidant natural products promoting hair growth in recent years and discuss the limitations and perspectives of current hair loss prevention and treatment.

Nuclear factor-κB p65 subunit determines the fate of aging epithelial cells.

Nuclear factor (NF)-κB signaling is not only important for the immune and inflammatory responses but also for the normal development of epithelial cells, such as those in the skin and tooth. Here, we generated epithelial cell-specific p65-deficient (p65Δepi-/-) mice to analyze the roles of NF-κB signaling in epithelial cell developent. Notably, p65Δepi-/- mice exhibited no abnormalities in their appearance compared to the control (p65flox/flox) littermates. Furthermore, no major changes were observed in the skin, hair growth, and shape and color of the incisors and molars. However, 65 % of p65Δepi-/- mice exhibited corneal thickening after 8 weeks of age, and 30 % of p65Δepi-/- mice exhibited hair growth from the mandibular incisors around 24 weeks of age. No hair growth was observed at 36 and 42 weeks of age. However, micro-computed tomography images revealed a large cavity below the mandibular incisors extending to the root of the incisor. Histological analysis revealed that the cavity was occupied by a connective tissue containing hair-like structures with many dark brown granules that disappeared after melanin bleaching, confirming the presence of hair. Although inflammatory cells were also observed near the eruption site of the incisor teeth of p65Δepi-/- mice, no major disturbance was observed in the arrangement of enamel epithelial cells. Overall, these results highlight the role of p65 in the maintenance of epithelial cell homeostasis during aging.

Exploring the puzzle of Reactive Oxygen Species (ROS) acting on root hair cells.

Reactive oxygen species (ROS) are essential signaling molecules that enable cells to respond rapidly to a range of stimuli. The capacity of plants to recognize various stressors, incorporate a variety of environmental inputs, and initiate stress-response networks depends on ROS. Plants develop resilience and defensive systems as a result of these processes. Root hairs (RHs) are central components of the root biology since they increase the surface area of the root, anchor it in the soil, increase its ability to absorb water and nutrients, and foster interactions between microorganisms. In this review, we specifically focused on RHs cells and we highlighted the identification of ROS receptors, important new regulatory hubs that connect ROS production, transport, and signaling in the context of two hormonal pathways (auxin and ethylene) and under low temperature environmental input related to nutrients. As ROS plays a crucial role in regulating cell elongation rates, RHs are rapidly gaining traction as a very valuable single plant cell model for investigating ROS homeostasis and signaling. These promising findings might soon aid in the development of plants and roots that are more resilient to environmental stressors.

Neurotensin counteracts hair growth inhibition induced by chronic restraint stress.

Stress has been considered as a potential trigger for hair loss through the neuroendocrine-hair follicle (HF) axis. Neurotensin (NTS), a neuropeptide, is known to be dysregulated in the inflammatory-associated skin diseases. However, the precise role of NTS in stress-induced hair loss is unclear. To investigate the function and potential mechanisms of NTS in stress-induced hair growth inhibition, we initially detected the expression of neurotensin receptor (Ntsr) and NTS in the skin tissues of stressed mice by RNA-sequencing and ELISA. We found chronic restraint stress (CRS) significantly decreased the expression of both NTS and Ntsr in the skin tissues of mice. Intracutaneous injection of NTS effectively counteracted CRS-induced inhibition of hair growth in mice. Furthermore, NTS regulated a total of 1093 genes expression in human dermal papilla cells (HDPC), with 591 genes being up-regulated and 502 genes being down-regulated. GO analysis showed DNA replication, cell cycle, integral component of plasma membrane and angiogenesis-associated genes were significantly regulated by NTS. KEGG enrichment demonstrated that NTS also regulated genes related to the Hippo signalling pathway, axon guidance, cytokine-cytokine receptor interaction and Wnt signalling pathway in HDPC. Our results not only uncovered the potential effects of NTS on stress-induced hair growth inhibition but also provided an understanding of the mechanisms at the gene transcriptional level.

Ginsenosides in Panax ginseng Extract Promote Anagen Transition by Suppressing BMP4 Expression and Promote Human Hair Growth by Stimulating Follicle-Cell Proliferation.

Studies showing that Panax ginseng promotes hair growth have largely been conducted using mice; there are few reports on how P. ginseng affects human hair growth. In particular, little is known about its effect on the telogen to anagen transition. To determine the effect of P. ginseng on human hair growth and the transition from the telogen to the anagen phase. The effects of P. ginseng extract (PGE) and the three major ginsenoside components, Rb1, Rg1, and Re, on the proliferation of human dermal papilla cells (DPCs) and human outer root sheath cells (ORSCs) were investigated. The effects of these compounds on the cell expression of bone morphogenetic protein 4 (BMP4), fibroblast growth factor 18 (FGF18) and Noggin were assessed by real-time PCR. The effect of PGE on hair-shaft elongation was determined in a human hair follicle organ-culture system. PGE and the three ginsenosides stimulated the proliferation of DPCs and ORSCs and suppressed BMP4 expression in DPCs but did not affect FGF18 expression in ORSCs and Noggin expression in DPCs. PGE stimulated hair-shaft growth. PGE and the ginsenosides Rb1, Rg1, and Re stimulate the transition from the telogen phase to anagen phase of the hair cycle by suppressing BMP4 expression in DPCs. These compounds might be useful for promoting the growth of human hair.

Efficacy of topical minoxidil in enhancing beard growth in a group of transgender assigned female at birth individuals on gender affirming hormone therapy.

PURPOSE: Testosterone therapy represents the cornerstone of gender affirming hormone therapy (GAHT) among t-AFAB (transgender Assigned Female At Birth) people. Minoxidil is a vasodilator drug approved for topical use for the treatment of androgenetic alopecia. The aim of the present study was to evaluate the efficacy of topical minoxidil in enhancing beard growth in a group of t-AFAB people on GAHT. METHODS: Sixteen t-AFAB individuals with an incomplete beard development, on GAHT for at least 6 months, were enrolled. Topical minoxidil was applied to the interested facial areas. Before starting (T0), after 3 (T3) and 6 (T6) months, we evaluated facial hair growth using the Ferriman-Gallwey modified score (FGm). RESULTS: Subjects were 26 (2.7) years old and on GAHT for 18.5 [15-54] months; using a paired match evaluation, a statistically significant facial hair growth was observed over time, in particular at T6 (median upper lip FGm 3.5 [3-4] vs 2 [1-2] at T0 and chin FGm 4 [3.25-4] vs 1 [1-2] at T0; p ≤ 0.002). Comparing the minoxidil group with a control group (n = 16) matched for age and BMI who developed a full-grown beard only with GAHT, a logistic multivariable analysis identified hirsutism before GAHT was independently positively associated with the development of a full beard [OR 15.22 (95% CI 1.46-158.82); p = 0.023]. CONCLUSIONS: This is the first study demonstrating the efficacy of topical minoxidil in enhancing facial hair growth among t-AFAB people on GAHT. Further studies will be necessary to assess whether the obtained improvements will persist after discontinuing the medication.

Serum lipids may causally affect the occurrence of alopecia areata: A Mendelian randomization study.

PURPOSE: The etiology of alopecia areata (AA) in relation to serum lipids remains unclear, thereby prompting our intention to do Mendelian study on this subject. DESIGN: Two-sample Mendelian randomization (MR) analysis was performed in the study. The inverse variance-weighted method was used as the primary method. METHODS: In our study, we integrated a set of 123 single-nucleotide polymorphisms (SNPs) into our analysis. These SNPs have been extensively studied and are known to exhibit associations with serum lipids. We sourced these SNPs from a variety of relevant studies and consortia that specifically focus on lipid-related research, such as the MRC Integrative Epidemiology Unit. These carefully curated SNPs were then utilized as instrumental variables in our analysis, allowing us to explore and evaluate the causal relationships between these genetic variants and serum lipids. By incorporating this comprehensive set of SNPs, we aimed to enhance the precision and robustness of our findings, shedding light on the intricate interplay between genetics and serum lipids. RESULTS: In the MR analysis, a higher total lipid concentration in large low-density lipoprotein (LDL) particles (odds ratio [OR] = 1.502; 95% confidence interval [CI] = 1.086-1.953; p = 0.006), a greater ratio of cholesteryl esters to total lipids in chylomicrons and extremely large very LDL (VLDL) particles (OR = 2.174; 95% CI = 1.300-2.500; p = 0.010), and a greater ratio of cholesterol to total lipids in chylomicrons and extremely large VLDL particles (OR = 2.363;95% CI = 1.556-4.438; p = 0.004), were genetically predicted to be causally associated with an increased risk of AA, while patients with a higher triglyceride to total lipids ratio in chylomicrons and extremely large VLDL particles had a lower risk of AA (OR = 0.481; 95% CI = 0.191-1.270; p = 0.002). CONCLUSION: This study found that serum lipids may be causally implicated in AA.

Intraoral laser hair removal: A scoping review.

PURPOSE: Intraoral hair growth is a debilitating side effect of flap or graft-based oropharyngeal reconstruction. There is no standardized treatment, but groups have successfully eradicated unwanted hair growth with intraoral laser hair removal. This scoping review assesses the utility of laser therapy in managing this condition. METHODS: This scoping review followed PRISMA-ScR guidelines. Ovid Medline, Embase (Ovid) and Scopus were queried using index terms and keywords. Resulting articles were reviewed for inclusion by two independent reviewers against inclusion criteria and relevant data were extracted. RESULTS: The literature search yielded 297 articles, 22 of which met inclusion criteria. In total, 77 patients were treated: 38 patients with an Alexandrite laser, 19 with an Nd:YAG laser, 18 with a diode laser, and two with a CO2 laser. Complete response defined as 80% or more reduction in hair count was achieved in 70 patients (90%) and six patients (8%) achieved a partial response (10%-79% reduction in hair count). One patient (1%) with gray hair saw less than a 10% reduction in hair count. On average, 3.84 treatment sessions were needed, spaced 5.4 weeks apart. Treatments were well tolerated without major side effects. CONCLUSIONS: This is the first scoping review assessing the utility of intraoral laser hair therapy and suggests it may be a safe and effective treatment. However, surgeons should advise preoperative hair removal when clinically feasible to mitigate this side effect as much as possible.

Management of androgenic alopecia: a systematic review of the literature.

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

Enhancement of skin rejuvenation and hair growth through novel near-infrared light emitting diode (nNIR) lighting: in vitro and in vivo study.

The study aimed to explore the impact of a novel near-infrared LED (nNIR) with an extended spectrum on skin enhancement and hair growth. Various LED sources, including White and nNIRs, were compared across multiple parameters: cytotoxicity, adenosine triphosphate (ATP) synthesis, reactive oxygen species (ROS) reduction, skin thickness, collagen synthesis, collagenase expression, and hair follicle growth. Experiments were conducted on human skin cells and animal models. Cytotoxicity, ATP synthesis, and ROS reduction were evaluated in human skin cells exposed to nNIRs and Whites. LED irradiation effects were also studied on a UV-induced photoaging mouse model, analyzing skin thickness, collagen synthesis, and collagenase expression. Hair growth promotion was examined as well. Results revealed both White and nNIR were non-cytotoxic to human skin cells. nNIR enhanced ATP and collagen synthesis while reducing ROS levels, outperforming the commonly used 2chip LEDs. In the UV-induced photoaging mouse model, nNIR irradiation led to reduced skin thickness, increased collagen synthesis, and lowered collagenase expression. Additionally, nNIR irradiation stimulated hair growth, augmented skin thickness, and increased hair follicle count. In conclusion, the study highlighted positive effects of White and nNIR irradiation on skin and hair growth. However, nNIR exhibited superior outcomes compared to White. Its advancements in ATP content, collagen synthesis, collagenase inhibition, and hair growth promotion imply increased ATP synthesis activity. These findings underscore nNIR therapy's potential as an innovative and effective approach for enhancing skin and promoting hair growth.

Prolactin: A Mammalian Stress Hormone and Its Role in Cutaneous Pathophysiology.

The hormone prolactin (PRL) is best recognised for its indispensable role in mammalian biology, specifically the regulation of lactation. Bearing in mind that the mammary gland is a modified sweat gland, it is perhaps unsurprising to discover that PRL also plays a significant role in cutaneous biology and is implicated in the pathogenesis of a range of skin diseases, often those reportedly triggered and/or exacerbated by psychological stress. Given that PRL has been implicated in over 300 biological processes, spanning reproduction and hair growth and thermo- to immunoregulation, a comprehensive understanding of the relationship between PRL and the skin remains frustratingly elusive. In an historical curiosity, the first hint that PRL could affect skin biology came from the observation of seborrhoea in patients with post-encephalitic Parkinsonism as a result of another global pandemic, encephalitis lethargica, at the beginning of the last century. As PRL is now being postulated as a potential immunomodulator for COVID-19 infection, it is perhaps timeous to re-examine this pluripotent hormone with cytokine-like properties in the cutaneous context, drawing together our understanding of the role of PRL in skin disease to illustrate how targeting PRL-mediated signalling may represent a novel strategy to treat a range of skin diseases and hair disorders.

Hair Growth Promoting Effects of 15-Hydroxyprostaglandin Dehydrogenase Inhibitor in Human Follicle Dermal Papilla Cells.

Prostaglandin E2 (PGE2) is known to be effective in regenerating tissues, and bimatoprost, an analog of PGF2α, has been approved by the FDA as an eyelash growth promoter and has been proven effective in human hair follicles. Thus, to enhance PGE2 levels while improving hair loss, we found dihydroisoquinolinone piperidinylcarboxy pyrazolopyridine (DPP), an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), using DeepZema®, an AI-based drug development program. Here, we investigated whether DPP improved hair loss in human follicle dermal papilla cells (HFDPCs) damaged by dihydrotestosterone (DHT), which causes hair loss. We found that DPP enhanced wound healing and the expression level of alkaline phosphatase in DHT-damaged HFDPCs. We observed that DPP significantly down-regulated the generation of reactive oxygen species caused by DHT. DPP recovered the mitochondrial membrane potential in DHT-damaged HFDPCs. We demonstrated that DPP significantly increased the phosphorylation levels of the AKT/ERK and activated Wnt signaling pathways in DHT-damaged HFDPCs. We also revealed that DPP significantly enhanced the size of the three-dimensional spheroid in DHT-damaged HFDPCs and increased hair growth in ex vivo human hair follicle organ culture. These data suggest that DPP exhibits beneficial effects on DHT-damaged HFDPCs and can be utilized as a promising agent for improving hair loss.

Clinical Studies Using Topical Melatonin.

Melatonin is ubiquitously present in all animals and plants, where it exerts a variety of physiological activities thanks to its antioxidant properties and its key role as the first messenger of extracellular signaling functions. Most of the clinical studies on melatonin refer to its widespread oral use as a dietary supplement to improve sleep. A far smaller number of articles describe the clinical applications of topical melatonin to treat or prevent skin disorders by exploiting its antioxidant and anti-inflammatory activities. This review focuses on the clinical studies in which melatonin was applied on the skin as a photoprotective, anti-aging, or hair growth-promoting agent. The methodologies and results of such studies are discussed to provide an overall picture of the state of the art in this intriguing field of research. The clinical studies in which melatonin was applied on the skin before exposure to radiation (UV, sunlight, and high-energy beams) were all characterized by an appropriate design (randomized, double-blind, and placebo-controlled) and strongly support its clinical efficacy in preventing or reducing skin damage such as dermatitis, erythema, and sunburn. Most of the studies examined in this review do not provide a clear demonstration of the efficacy of topical melatonin as a skin anti-aging or as a hair growth-promoting agent owing to limitations in their design and/or to the use of melatonin combined with extra active ingredients, except for one trial that suggests a possible beneficial role of melatonin in treating some forms of alopecia in women. Further research efforts are required to reach definitive conclusions concerning the actual benefits of topical melatonin to counteract skin aging and hair loss.

Optimization of Bear Oil Extraction Process and Hair Growth Activity.

According to ancient Chinese books, bear grease has the effects of strengthening muscles and bones, which is beneficial for weakness, but there is relatively little research on it. Thus, the extraction of it is beneficial for compensating for research in this area. In this study, a uniform experimental design method was used to optimize the extraction process of bear grease by enzymatic hydrolysis extraction, and the extraction rate can reach 81.89% under optimized extraction conditions. Furthermore, the components of bear grease obtained by this study were analyzed by GC-MS, and the results showed that ursolic oil was rich in unsaturated fatty acids (67.51%), which was higher than that of the traditional method (66.92%). The composition of bear grease extracted by the enzymatic method was also better than that extracted by the traditional method. In addition, bear grease obtained in this study had the obvious activity of promoting hair growth. The length, weight, and number of hair follicles in the depilation area of mice in the high-dose group were significantly different from those in the blank group (p < 0.01). This study optimized the extraction process of bear grease and conducted a preliminary analysis of its fatty acid composition, which is expected to provide some reference for the development of the medicinal value of bear grease.

The formulation and in vitro evaluation of WS Biotin, a novel encapsulated form of D-Biotin with improved water solubility for hair and skin treatment applications.

OBJECTIVE: To develop and evaluate the efficacy of WS Biotin, a novel water-soluble form of D-Biotin, for cosmetic use. METHODS: A new encapsulated form of D-Biotin was developed with the purpose of improving the water solubility of biotin. This novel form of encapsulated biotin was characterized by 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, an ELISA test was conducted for hair keratinization and skin lightening property was tested by analysing the intracellular melanin content. RESULTS: 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 greater 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. CONCLUSION: 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.

OBJECTIF: Développer et évaluer l'efficacité de la WS Biotin, une nouvelle forme hydrosoluble de D-biotine, à usage cosmétique. MÉTHODES: Une nouveau format gélules de D-biotine a été développé dans le but d'améliorer la propriété d'hydrosolubilité de la biotine. Ce nouveau format de gélules de biotine a été caractérisé pour ses propriétés physicochimiques : taille des particules, teneur en D-biotine et solubilité dans l'eau. En outre, des tests in vitro de prolifération et d'expression génique en culture cellulaire ont été réalisés pour évaluer son efficacité à favoriser la croissance des cheveux, un test ELISA a été réalisé pour la kératinisation des cheveux et la propriété d'éclaircissement de la peau a été testée en analysant la teneur en mélanine intracellulaire. RÉSULTATS: Les microgélules de WS Biotin développées présentent une plage de tailles de particules de 2 à 30 micromètres avec une teneur en biotine D d'environ 50 % (p/p). L'hydrosolubilité de WS Biotin s'est avérée 20 fois plus élevée que celle de la biotine libre. Les résultats in vitro obtenus ont indiqué que WS Biotin améliorait l'expression des kératines capillaires dans les kératinocytes des follicules pileux, ainsi que l'expression des gènes favorisant la croissance dans les cellules papillaires dermiques. En outre, la teneur en mélanine dans les mélanocytes épidermiques exposés aux UVA a été réduite lors de l'exposition à WS Biotin. CONCLUSION: Dans ce travail, une nouvelle forme de biotine en gélule, WS Biotin, a été développée afin d'améliorer l'hydrosolubilité de la biotine libre et s'est avérée efficace pour une utilisation cosmétique dans les applications capillaires et cutanées.

Surfactin as an ingredient in cosmetic industry: Benefits and trends.

Surfactin is a natural surfactant almost exclusively produced by Bacillus species with excellent physical-chemical, and biological properties. Among innovative applications, surfactin has been recently used as an ingredient in formulations. The antibacterial and anti-acne activities, as well as the anti-wrinkle, moisturizing, and cleansing features, are some of the reasons this lipopeptide is used in cosmetics. Considering the importance of biosurfactants in the world economy and sustainability, their potential properties for cosmetic and dermatological products, and the importance of patents for technological advancement in a circular bioeconomy system, the present study aims to review all patents involving surfactin as an ingredient in cosmetic formulas. This review was conducted through Espacenet, wherein patents containing the terms "cosmetic" and "surfactin" in their titles, abstracts, or claims were examined. Those patents that detailed a specific surfactin dosage within their formulations were selected for analysis. All patents, irrespective of their publication date, from October 1989 to December 2022, were considered. Additionally, a comprehensive search was performed in the MEDLINE and EMBASE databases, spanning from their inception until the year 2023. This complementary search aimed to enrich the understanding derived from patents, with a specific emphasis on surfactin, encompassing its associated advantages, efficacy, mechanisms of action on the skin, as well as aspects related to sustainability and its merits in cosmetic formulations. From the 105 patents analysed, 75% belong to Japan (54), China (14), and Korea (9). Most of them were submitted by Asian companies such as Showa Denko (15), Kaneka (11) and Kao Corporation (5). The formulations described are mainly emulsions, skincare, cleansing, and haircare, and the surfactin dose does not exceed 5%. Surfactin appears in different types of formulas worldwide and has a high tendency to be used. Surfactin and other biosurfactants are a promising alternative to chemical ingredients in cosmetic formulations, guaranteeing skin health benefits and minimizing the impact on the environment.

OBJECTIF: La surfactine est un agent tensioactif naturel presque exclusivement produit par les espèces de Bacillus, qui présente d'excellentes propriétés physico-chimiques et biologiques. Parmi les applications innovantes, la surfactine a été récemment utilisée comme ingrédient dans les formulations. Les activités antibactériennes et anti-acnéiques, ainsi que les propriétés antirides, hydratantes et nettoyantes, sont quelques-unes des raisons pour lesquelles ce lipopeptide est utilisé dans les cosmétiques. Compte tenu de l'importance des biosurfactants pour l'économie mondiale et la durabilité, de leurs propriétés potentielles pour les produits cosmétiques et dermatologiques, et de l'importance des brevets pour les progrès technologiques dans un système de bioéconomie circulaire, la présente étude vise à passer en revue tous les brevets impliquant la surfactine en tant qu'ingrédient dans les formules cosmétiques. MÉTHODES: Cet examen a été mené en utilisant Espacenet, dans lequel les brevets contenant les termes « cosmétique ¼ et « surfactine ¼ dans leurs titres, résumés ou revendications ont été examinés. Les brevets détaillant un dosage spécifique de surfactine dans leurs formulations ont été sélectionnés pour l'analyse. Tous les brevets, quelle que soit leur date de publication, d'octobre 1989 à décembre 2022, ont été pris en compte. En outre, une recherche complète a été effectuée dans les bases de données MEDLINE et EMBASE, depuis leur création jusqu'à l'année 2023. Cette recherche complémentaire visait à enrichir la compréhension dérivée de brevets, en mettant l'accent sur la surfactine, ses avantages associés, son efficacité, ses mécanismes d'action sur la peau, ainsi que les aspects liés à la durabilité et ses mérites dans les formulations cosmétiques. RÉSULTATS: Sur les 105 brevets analysés, 75 % appartiennent au Japon (54), à la Chine (14) et à la Corée (9). La plupart d'entre eux ont été soumis par des sociétés asiatiques telles que Showa Denko (15), Kaneka (11) et Kao Corporation (5). Les formulations décrites sont principalement des émulsions, des soins de la peau, des nettoyants et des soins capillaires, et la dose de surfactine n'excède pas 5 %. CONCLUSIONS: La surfactine apparaît dans différents types de formules dans le monde et conserve une forte tendance à l'utilisation. La surfactine et d'autres biosurfactants sont une alternative prometteuse aux ingrédients chimiques dans les formulations cosmétiques, garantissant des bénéfices pour la santé de la peau et minimisant l'impact sur l'environnement.

A consumer cross-over trial suggests that there are significant seasonal changes of the tensile properties (wet) of human hair.

OBJECTIVES: Through the cooperation with an industrial partner, we gained a set of data for the tensile properties (wet) of human hair. The hair samples originated from a cross-over study with two groups of individuals, using for a topical application sequentially two products (A and B). Each phase of the study lasted 6 months. The phases of the study by chance covered first largely the winter and then the summer period. Initially, tensile variables were chosen, which not only reflect the mechanical properties of hair (modulus, break strain, and break stress) but which are also considered to have a good connection to practice-relevant hair properties. The initial analysis of the data showed that changes were observed for the variables due to the treatment phases. However, these were either small or difficult to interpret. METHODS: Against this background and using two-factor analysis of variance, we investigated the hypothesis that the tensile properties of hair (wet) may show significant seasonal changes. For this, we chose those two independent variables, which reflect the properties of the intermediate filaments (modulus) and the matrix (break strain) in the composite structure of the hair cortex. RESULTS: The results support the 'seasonal' hypothesis and clearly show that the variables show significant changes from Winter to Summer (modulus: 10% increase; break strain: 3% decrease). The seasonal effect was thus a major reason, why the first stage of the analysis of the data was inconclusive. CONCLUSIONS: The tensile properties of the main morphological components of the cortex show distinct seasonal changes. Towards the summer, the hair becomes stiffer and more brittle. Furthermore, the results suggest that seasonal effects may need to be taken into account when conducting studies on lengths of hair grown during different seasons.

OBJECTIFS: Grâce à la coopération avec un partenaire industriel, nous avons obtenu un ensemble de données sur les propriétés de traction des cheveux (humides) humains. Les échantillons de cheveux provenaient d'une étude croisée avec deux groupes de personnes, utilisant pour une application topique deux produits (A et B) de manière séquentielle. Chaque phase de l'étude a duré 6 mois. Les phases de l'étude ont principalement couvert l'hiver, puis l'été. Initialement les variables de traction ont été choisies reflètent non seulement les propriétés mécaniques des cheveux (modulus, extension de rupture et stress de rupture), mais sont également considérées comme ayant un lien étroit avec les propriétés pertinentes des cheveux. L'analyse initiale des données a montré que des changements ont été observés pour les variables en raison des phases de traitement. Cependant, ils étaient faibles ou difficiles à interpréter. MÉTHODES: Dans ce contexte et à l'aide d'une analyse de variance à deux facteurs, nous avons étudié l'hypothèse selon laquelle les propriétés de traction des cheveux (humides) pourraient montrer des changements saisonniers significatifs. Pour cela, nous avons choisi ces deux variables indépendantes, qui reflètent les propriétés des filaments intermédiaires (modulus) et de la matrice (extension de rupture) dans la structure composite du cortex capillaire. RÉSULTATS: Les résultats appuient l'hypothèse « saisonnière ¼ et indiquent clairement que les variables montrent des évolutions significatives de l'hiver à l'été (modulus : augmentation de 10 % ; extension de rupture : diminution de 3 %). L'effet saisonnier était donc une raison majeure pour laquelle la première étape de l'analyse des données n'a pas été concluante. CONCLUSIONS: Les propriétés de traction des principaux composants morphologiques du cortex montrent des changements saisonniers distincts. Vers l'été, les cheveux deviennent plus raides et plus cassants. En outre, les résultats indiquent que les effets saisonniers devrait être pris en compte lors de la réalisation d'études sur les longueurs des cheveux ayant poussé à différentes saisons.

Efficacy of a wheat polar lipid complex in reducing hair loss and improving hair growth in healthy women: A randomized, double-blind, placebo-controlled clinical study.

OBJECTIVE: Hair loss is a major source of psychological distress for affected people. Safe and natural ingredients are therefore needed to help reduce hair loss and stimulate hair growth. This pilot clinical study aimed at exploring the efficacy of a wheat polar lipid complex (WPLC, Ceramosides™), containing sphingolipids and digalactosyl diglycerides, on hair characteristics improvement in women showing acute hair shedding. METHODS: Sixty-six women presenting a proportion of hair in the telogen phase greater than 15% were recruited and allocated to two groups, each including at least 10 postmenopausal women. For 84 days, participants consumed 30 mg/day of the WPLC supplement, or the placebo. Their hair characteristics were assessed after 56 and 84 days using phototrichogram evaluations of hairs in anagen/telogen phases, measuring hair shedding by a pull test, hair diameter and elongation at break point, hair growth and scalp sebum content. Hair density and volume were also clinically evaluated. All these parameters were also investigated in the subgroup of postmenopausal women. RESULTS: WPLC supplementation decreased telogen hair density/proportion while increasing the anagen hair density/proportion. These effects were significant compared with the placebo as early as within 56 days. It also led to reduced hair shedding upon pull test analyses. If no changes were evidenced in hair diameter, WPLC improved hair growth and resistance to breakage after 84 days. Clinical evaluations also showed hair density and volume improvement. Furthermore, supplementation decreased scalp sebum content in women with oily hair. The beneficial effects were also observed in the subgroup of postmenopausal women. Finally, WPLC supplementation improved participants' perception of their hair conditions. CONCLUSION: Through a reducing effect on hair shedding and a stimulating effect on hair reappearance and growth, WPLC dietary supplementation was shown to significantly reduce hair loss in women.

OBJECTIF: La chute de cheveux est une source importante de détresse psychologique pour les personnes concernées. Des ingrédients naturels et sûrs sont nécessaires pour permettre de réduire la chute et stimuler la croissance des cheveux. Cette étude clinique pilote avait pour objectif d'étudier la capacité d'un complexe de lipides polaires extraits du blé (WPLC), composé de sphingolipides et de digalactosyl diglycerides, à améliorer la qualité des cheveux chez des femmes présentant une chute de cheveux diffuse et aiguë. MÉTHODES: Soixante­six femmes présentant un taux de cheveux en phase télogène supérieur à 15% ont été recrutées et séparées en deux groupes, chacun comprenant au moins dix femmes ménopausées. Pendant 84 jours, les volontaires ont consommé le supplément à une dose de 30 mg/jour, ou le placebo. Leur chevelure a été évaluée après 56 et 84 jours de supplémentation en quantifiant les cheveux en phase anagène/télogène grâce à un phototrichogramme, en évaluant la chute de cheveux grâce à un test de traction, en mesurant le diamètre, l'élongation et la croissance des cheveux, et en quantifiant le taux de sébum du cuir chevelu. La densité et le volume de la chevelure ont été évalués cliniquement. Tous ces paramètres ont également été analysés dans le sous­groupe de femmes ménopausées. RÉSULTATS: Une diminution de la densité et de la proportion des cheveux en phase télogène a été observée, en association avec une augmentation de la densité et de la proportion des cheveux en phase anagène. Ces résultats sont statistiquement significatifs en comparaison avec le placebo, et ce, dès 56 jours. La chute de cheveux, mesurée par le test de traction, a également été significativement réduite. Bien qu'aucun changement n'ait été observé concernant le diamètre des cheveux, le supplément a amélioré la résistance à la casse et la croissance des cheveux après 84 jours d'utilisation. L'évaluation clinique a montré une amélioration de la densité et du volume de la chevelure. De plus, la supplémentation a entraîné une réduction du taux de sébum du cuir chevelu chez les femmes présentant des cheveux à tendance grasse. Les effets bénéfiques de la supplémentation ont également été observés dans le sous­groupe des femmes ménopausées. Enfin, la prise du supplément a également été associée à une amélioration de la perception des volontaires concernant la qualité de leurs cheveux. CONCLUSION: Grâce à un effet réducteur sur la chute de cheveux et un effet stimulateur sur la repousse et la croissance des cheveux, cette étude a démontré l'efficacité de la supplémentation nutritionnelle avec WPLC à atténuer la perte de cheveux chez la femme.

Mechanical epilation exerts complex biological effects on human hair follicles and perifollicular skin: An ex vivo study approach.

OBJECTIVE: Electrical epilation of unwanted hair is a widely used hair removal method, but it is largely unknown how this affects the biology of human hair follicles (HF) and perifollicular skin. Here, we have begun to explore how mechanical epilation changes selected key biological read-out parameters ex vivo within and around the pilosebaceous unit. METHODS: Human full-thickness scalp skin samples were epilated ex vivo using an electro-mechanical device, organ-cultured for up to 6 days in serum-free, supplemented medium, and assessed at different time points by quantitative (immuno-)histomorphometry for selected relevant read-out parameters in epilated and sham-epilated control samples. RESULTS: Epilation removed most of the hair shafts, often together with fragments of the outer and inner root sheath and hair matrix. This was associated with persistent focal thinning of the HF basal membrane, decreased melanin content of the residual HF epithelium, and increased HF keratinocyte apoptosis, including in the bulge, yet without affecting the number of cytokeratin 15+ HF epithelial stem cells. Sebocyte apoptosis in the peripheral zone was increased, albeit without visibly altering sebum production. Epilation transiently perturbed HF immune privilege, and increased the expression of ICAM-1 in the bulge and bulb mesenchyme, and the number of perifollicular MHC class II+ cells as well as mast cells around the distal epithelium and promoted mast cell degranulation around the suprabulbar and bulbar area. Moreover, compared to controls, several key players of neurogenic skin inflammation, itch, and/or thermosensation (TRPV1, TRPA1, NGF, and NKR1) were differentially expressed in post-epilation skin. CONCLUSION: These data generated in denervated, organ-cultured human scalp skin demonstrate that epilation-induced mechanical HF trauma elicits surprisingly complex biological responses. These may contribute to the delayed re-growth of thinner and lighter hair shafts post-epilation and temporary post-epilation discomfort. Our findings also provide pointers regarding the development of topically applicable agents that minimize undesirable sequelae of epilation.

OBJECTIF: L'épilation électrique des poils indésirables est une méthode d'épilation largement utilisée, mais on ne connaît pas l'ampleur de son effet sur la biologie des follicules pileux humains (FP) et de la peau périfolliculaire. Dans cette étude, nous avons commencé à explorer comment l'épilation mécanique modifie certains paramètres de mesures biologiques clés ex vivo à l'intérieur et autour de l'unité pilo­sébacée. MÉTHODES: Des échantillons de peau du cuir chevelu humain de pleine épaisseur ont été épilés ex vivo à l'aide d'un dispositif électromécanique, cultivés biologiquement pendant un maximum de 6 jours dans un milieu complet sans sérum, et évalués à différents moments par (immuno­)histomorphométrie quantitative pour certains paramètres de mesures pertinents dans des échantillons avec épilation et des échantillons témoins avec épilation simulée. RÉSULTATS: L'épilation a enlevé la plupart des poils, souvent avec des fragments de la gaine de la racine externe et de la matrice pileuse. Cela a été associé à un amincissement focal persistant de la membrane basale du FP, à une diminution de la teneur en mélanine de l'épithélium résiduel du FP et à une augmentation de l'apoptose des kératinocytes du FP, y compris dans la surface arrondie, mais sans affecter le nombre de cellules souches épithéliales du FP positives pour la cytokératine 15. L'apoptose des sébocytes de la zone périphérique était augmentée, sans pour autant altérer visiblement la production de sébum. L'épilation a temporairement perturbé l'immunoprivilège du FP et a augmenté l'expression de l'ICAM­1 dans la surface arrondie et le mésenchyme du bulbe, ainsi que le nombre de cellules périfolliculaires du CMH de classe II et des mastocytes autour de l'épithélium distal, et a favorisé la dégranulation des mastocytes autour de la zone supra­bulbaire et bulbaire. En outre, par rapport aux échantillons témoins, plusieurs acteurs clés de l'inflammation neurogène cutanée, de la démangeaison et/ou de la thermosensation (TRPV1, TRPA1, NGF et NKR1) ont été exprimés de manière différentielle dans la peau après l'épilation. CONCLUSION: Ces données générées dans la peau du cuir chevelu humain dénervée et cultivée biologiquement démontrent que le traumatisme du FP induit par l'épilation mécanique provoque des réponses biologiques étonnamment complexes. Celles­ci peuvent contribuer à retarder la repousse des poils plus fins et plus clairs après l'épilation, et à provoquer une gêne temporaire après l'épilation. Nos résultats fournissent également des pistes concernant le développement d'agents applicables par voie topique qui minimisent les séquelles indésirables de l'épilation.

Spectral histology of hair and hair follicle using infrared microspectroscopy.

OBJECTIVE: Today, there is only limited knowledge of the spatial organization of hair chemistry. Infrared microspectroscopy is a well-established tool to provide such information and has significantly contributed to this field. In this study, we present new results combining multiple infrared microspectroscopy methods at different length scales to create a better chemical histology of human hair, including the hair follicle, hair shaft, hair medulla and hair cuticle. METHODS: We used hyperspectral IR imaging & spectroscopy (HIRIS) and synchrotron-radiation FTIR microspectroscopy (SR-µFTIR) to measure transversal hair sections and SR-µFTIR to obtain high-resolution maps of longitudinal sections from the hair shaft and from the hair follicle. We used optical photothermal IR microspectroscopy (OPTIR) to analyse the cuticle surface of intact hairs. RESULTS: By mapping longitudinal sections of the human hair follicle with confocal SR-µFTIR, we report the first demonstration of glycogen presence in the outer root sheath of the hair follicle by spectroscopy, and its quantification at the micron scale. Spectral maps, combined with machine learning-based analysis, enabled us to differentiate the various layers of the hair follicle and provided insights into the chemical changes that occur during hair formation in the follicle. Using HIRIS and SR-µFTIR to analyse the hair medulla in transversal sections of human hairs, we report here, for the first time by vibrational spectroscopy methods, the detection of unsaturated lipids at very low concentrations in the medulla. By analysing longitudinal sections of the hair shaft with SR-µFTIR, we found that calcium carboxylates are present in large regions of the hair cuticle, and not just in small focal areas as previously thought. We then use OPTIR to analyse the hair cuticle of intact hairs at submicron resolution without sectioning and report the distribution of calcium carboxylates at the surface of intact hair for the first time. CONCLUSION: These new findings illustrate the potential of infrared microspectroscopy for imaging the chemical composition of human hair and may have implications for biomedical research or cosmetology.

OBJECTIF: Aujourd'hui, les connaissances sur l'organisation spatiale de la chimie capillaire sont limitées. La microspectroscopie infrarouge est un outil bien établi pour fournir de telles informations et a largement contribué à ce domaine. Dans cette étude, nous présentons de nouveaux résultats combinant plusieurs méthodes de microspectroscopie infrarouge à différentes échelles de longueur pour créer une meilleure histologie chimique des cheveux humains, y compris le follicule pileux, la tige pilaire, la moelle pilaire et la cuticule pilaire. MÉTHODES: Nous avons utilisé l'imagerie et la spectroscopie hyperspectrales infrarouges (Hyperspectral IR Imaging & Spectroscopy, HIRIS) et la microspectroscopie IRTF par rayonnement synchrotron (synchrotron­radiation FTIR microspectroscopy, SR­µFTIR) pour mesurer des coupes transversales de cheveux, et la SR­µFTIR pour obtenir des cartes à haute résolution des coupes longitudinales de la tige pilaire et du follicule pileux. Nous avons utilisé la microspectroscopie photothermique infrarouge optique (Optical Photothermal IR microspectroscopy, OPTIR) pour analyser la surface des cuticules de cheveux intacts. RÉSULTATS: En cartographiant les coupes longitudinales du follicule pileux humain avec la SR­µFTIR confocale, nous rapportons la première démonstration par spectroscopie de la présence de glycogène dans la gaine de la racine externe du follicule pileux, et sa quantification à l'échelle du micron. Les cartes spectrales, combinées à une analyse basée sur l'apprentissage automatisé, nous ont permis de différencier les différentes couches du follicule pileux et de mieux comprendre les changements chimiques qui surviennent pendant la formation des cheveux dans le follicule. En utilisant la méthode HIRIS et la SR­µFTIR pour analyser la moelle pilaire dans les coupes transversales des cheveux humains, nous rapportons ici, pour la première fois par des méthodes de spectroscopie vibrationnelle, la détection de lipides insaturés à de très faibles concentrations dans la moelle. En analysant les coupes longitudinales de la tige pilaire par SR­µFTIR, nous avons constaté que les carboxylates de calcium sont présents dans de vastes régions de la cuticule pilaire, et pas seulement dans de petites zones focales comme on le pensait auparavant. Nous utilisons ensuite la méthode OPTIR pour analyser la cuticule pilaire de cheveux intacts à une résolution inférieure au micron sans sectionner les cheveux et rapportons pour la première fois la distribution des carboxylates de calcium à la surface des cheveux intacts. CONCLUSION: Ces nouveaux résultats illustrent le potentiel de la microspectroscopie infrarouge pour l'imagerie de la composition chimique des cheveux humains et peuvent avoir des implications pour la recherche biomédicale ou la cosmétologie.