Delta opioid receptor expression correlates to skin ageing and melanin expression in Asian women.

While the evidence for the implication of opioid receptors (OPr) in ageing is growing, there is, to our knowledge, no study focusing directly on changes in vivo cutaneous OPr expression with increasing age. We thus investigated OPr expression in 30 healthy female Asian volunteers in Southern China whose ages range from the early 20s to the early 60s. Excisional biopsies were taken from the sun-exposed extensor area of the lower arm and the photo-protected area of the upper inner arm. The thickness of the epidermal layers, melanin content, as well as expression of mu-opioid receptors (MOPr) and delta-opioid receptors (DOPr) were compared between different age ranges and photo-exposure status. Significant increased epidermal hypertrophy on the extensor surface was observed. There was significant reduction of DOPr in the epidermis with increasing age, independent of photo-ageing. The increase of melanin was significantly correlated with epidermal DOPr expression, not with MOPr expression. DOPr expression could thus serve as a marker for real biological ageing unaffected by chronic photo-exposure. Additionally, DOPr expression was inversely correlated with the deposition of melanin. Based on these results, we hypothesise that regulation of DOPr expression could be used to improve aged skin, including hyperpigmentation.

The impact of air pollution on the facial skin of Caucasian women using real-life pollutant exposure measurements.

BACKGROUND: To date, studies examining the effect of air pollution on skin characteristics have relied on regional pollution estimates obtained from fixed monitoring sites. Hence, there remains a need to characterize the impact of air pollution in vivo in real-time conditions. We conducted an initial investigation under real-life conditions, with the purpose of characterizing the in vivo impact of various pollutants on the facial skin condition of women living in Paris over a 6-month period. MATERIALS AND METHODS: A smartphone application linked to the Breezometer platform was used to collect participants' individual exposures to pollutants through the recovery of global positioning system (GPS) data over a 6-month period. Daily exposure to fine particulate matter (PM 2.5 µm and PM 10 µm), pollen, and air quality was measured. Facial skin color, roughness, pore, hydration, elasticity, and wrinkle measurements were taken at the end of the 6-month period. Participants' cumulated pollutant exposure over 6 months was calculated. Data were stratified into two groups (lower vs. higher pollutant exposure) for each pollutant. RESULTS: 156 women (20-60 years-old) were recruited, with 124 women completing the study. Higher PM 2.5 µm exposure was associated with altered skin color and increased roughness under the eye. Higher PM 10 µm exposure with increased wrinkles and roughness under the eye, increased pore appearance, and decreased skin hydration. Exposure to poorer air quality was linked with increased forehead wrinkles and decreased skin elasticity, while higher pollen exposure increased skin roughness and crow's feet. CONCLUSION: This study suggests a potential correlation between air pollution and facial skin in real-life conditions. Prolonged exposure to PM, gases, and pollen may be linked to clinical signs of skin ageing. This study highlights the importance of longer monitoring over time in real conditions to characterize the effect of pollution on the skin.

Age-related changes in the bacterial composition of healthy female facial skin in Beijing area.

OBJECTIVE: Exploring the effects of age on microbial community structure and understanding the effects of chronological ageing as well as sun exposure on microbial community diversity. METHOD: The microbial characteristics of the facial skin of 98 adult women aged 18-70 years were studied using 16S rRNA gene sequencing, and differences based on age and reported sun exposure were assessed. RESULTS: The cheek skin's bacterial diversity and richness increased with age. The relative abundance of Cutibacterium decreased with age, while the relative abundance of Corynebacterium, Anaerococcus, Paracoccus, Micrococcus, Kocuria, Kytococcus, and Chryseobacterium increased. In addition, an increase in Micrococcus and a decrease in Cutibacterium were observed in volunteers with more than 2 h of daily sun exposure compared to volunteers with <2 h of daily sun exposure. Under low-sunlight conditions, Cutibacterium was more prevalent in the youth group, and Corynebacterium, Anaerococcus, and Kytococcus were more prevalent in the older group. CONCLUSION: The diversity and composition of the bacterial community on the cheeks are affected by age and extrinsic factors (sun exposure) may also play a role in this.

OBJECTIF: Étudier les effets de l'âge sur la structure de la communauté microbienne et comprendre les effets du vieillissement chronologique ainsi que de l'exposition au soleil sur la diversité de la communauté microbienne. MÉTHODE: Les caractéristiques microbiennes de la peau du visage de 98 femmes adultes âgées de 18 à 70 ans ont été étudiées à l'aide du séquençage génétique de l'ARNr 16S, et les différences basées sur l'âge et l'exposition au soleil rapportée ont été évaluées. RÉSULTAT: La diversité et la richesse bactériennes de la peau des joues ont augmenté avec l'âge. L'abondance relative de Cutibacterium a diminué avec l'âge, tandis que l'abondance relative de Corynebacterium, Anaerococcus, Paracoccus, Micrococcus, Kocuria, Kytococcus et Chryseobacterium a augmenté. De plus, une augmentation de Micrococcus et une diminution de Cutibacterium ont été observées chez des volontaires ayant été exposés au soleil pendant plus de 2 heures par jour par rapport à des volontaires ayant été exposés au soleil pendant moins de 2 heures par jour. Dans des conditions de faible luminosité, Cutibacterium était plus prévalent dans le bras des personnes jeunes, et Corynebacterium, Anaerococcus et Kytococcus étaient plus prévalents dans le bras des personnes plus âgées. CONCLUSION: La diversité et la composition de la communauté bactérienne sur les joues sont affectées par l'âge et des facteurs extrinsèques (exposition au soleil) peuvent également y jouer un rôle.

Anti-skin ageing activities of rice (Oryza sativa) bran soft and hard waxes in cultured skin cells.

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

OBJECTIF: Les cires de son de riz (Oryza sativa) et les sous­produits de la fabrication de l'huile de son de riz sont largement utilisées comme composants inactifs dans plusieurs préparations. Néanmoins, l'effet des cires de son de riz contre le vieillissement de la peau n'a jamais été rapporté. Cette étude visait à étudier les propriétés thermiques et le profil d'acides gras des cires de son de riz, y compris les cires dures et douces de son de riz, et les activités contre le vieillissement de la peau dans les cellules cutanées en culture. MÉTHODES: La propriété thermique et le profil d'acides gras des cires de son de riz ont été analysés par calorimétrie différentielle à balayage et chromatographie en phase gazeuse couplée spectrométrie de masse, respectivement. Le dosage de la cytotoxicité des cires a été réalisé sur des cellules de mélanome B16F10, des fibroblastes de peau humaine, et des cellules de co­culture de cellules HaCaT et des fibroblastes de peau humaine. Les concentrations non cytotoxiques des cires ont été évaluées pour leurs activités contre le vieillissement de la peau, y compris l'analyse de la mélanogenèse, l'activité antioxydante, l'analyse de la teneur en collagène, le test de l'inhibiteur de la métalloprotéinase matricielle­1 et de la métalloprotéinase matricielle­2 et l'activité anti­inflammatoire. RÉSULTATS: La propriété thermique indiquait des pics endothermes avec des températures de fusion à 40,89 ± 0,27 °C et 69,64 ± 0,34 °C pour les cires dures et douces de son de riz, respectivement. Les principaux acides gras des cires douces de son de riz étaient des acides oléiques (31,68 ± 0,75 %) et des acides linoléiques (27,19 ± 0,40 %), tandis que ceux des cires dures de son de riz étaient des acides palmitiques (36,24 ± 1,08 %) et des acides stéariques (35,21 ± 4,51 %). Le dosage de la cytotoxicité dans les cellules individuelles et les cellules de co­culture a montré la non­cytotoxicité des cires douces de son de riz (0,0001 à 1 mg/ml) et des cires dures de son de riz (0,0001 à 0,1 mg/ml). Les activités antivieillissement de la peau de 1 mg/ml de cire douce de son de riz et de 0,1 mg/ml de cire dure de son de riz comprenaient l'inhibition de la mélanogenèse par suppression des enzymes de la tyrosinase et de la protéine liée à la tyrosinase 2, l'activité antioxydante par protection cellulaire contre les dommages et la mort cellulaires, la stimulation du collagène, la suppression de la métalloprotéinase matricielle­1 et la métalloprotéinase matricielle­2 et l'activité anti­inflammatoire. CONCLUSIONS: Les résultats de l'étude indiquent que les cires dures et douces de son de riz peuvent potentiellement être appliquées comme ingrédients fonctionnels dans des formulations contre le vieillissement de la peau et fournir un bénéfice supérieur en termes d'hydratation de la peau.

Unlocking the role of herbal cosmeceutical in anti-ageing and skin ageing associated diseases.

The process of skin ageing is a natural biological phenomenon characterised by the emergence of wrinkles, age spots, sagging skin, and dryness over time. The increasing significance of skin in physical attractiveness has heightened skincare concerns. Anti-ageing cosmetics play a pivotal role in nurturing the skin, enhancing its quality, and promoting overall health. Today, cosmetics have evolved beyond mere aesthetics and are now integral to individual wellness. The contemporary quest for perpetual youth has intensified, prompting a deeper exploration into the skin ageing process. This comprehensive exploration delves into various elements involved in skin ageing, encompassing cells such as stem and endothelial cells, blood vessels, soft tissues, and signalling pathways. The molecular basis of skin ageing, including biochemical factors like reactive oxygen species, damaged DNA, free radicals, ions, and proteins (mRNA), is scrutinised alongside relevant animal models. The article critically analyzes the outcomes of utilising herbal components, emphasising their advantageous anti-ageing properties. The factors contributing to skin ageing, mechanistic perspectives, management approaches involving herbal cosmeceutical, and associated complications (especially cardiovascular diseases, Parkinson's, Alzheimer's, etc.) are succinctly addressed. In addition, the manuscript further summarises the recent patented innovations and toxicity of the herbal cosmeceuticals for anti-ageing and ageing associated disorders. Despite progress, further research is imperative to unlock the full potential of herbal components as anti-ageing agents.

Senescent human melanocytes drive skin ageing via paracrine telomere dysfunction.

Cellular senescence has been shown to contribute to skin ageing. However, the role of melanocytes in the process is understudied. Our data show that melanocytes are the only epidermal cell type to express the senescence marker p16INK4A during human skin ageing. Aged melanocytes also display additional markers of senescence such as reduced HMGB1 and dysfunctional telomeres, without detectable telomere shortening. Additionally, senescent melanocyte SASP induces telomere dysfunction in paracrine manner and limits proliferation of surrounding cells via activation of CXCR3-dependent mitochondrial ROS. Finally, senescent melanocytes impair basal keratinocyte proliferation and contribute to epidermal atrophy in vitro using 3D human epidermal equivalents. Crucially, clearance of senescent melanocytes using the senolytic drug ABT737 or treatment with mitochondria-targeted antioxidant MitoQ suppressed this effect. In conclusion, our study provides proof-of-concept evidence that senescent melanocytes affect keratinocyte function and act as drivers of human skin ageing.

Quantitative morphometric analysis of intrinsic and extrinsic skin ageing in individuals with Fitzpatrick skin types II-III.

Skin ageing is an intricate physiological process affected by intrinsic and extrinsic factors. There is a demand to understand how the skin changes with age and photoexposure in individuals with Fitzpatrick skin types I-III due to accelerated photoageing and the risk of cutaneous malignancies. To assess the structural impact of intrinsic and extrinsic ageing, we analysed 14 skin parameters from the photoprotected buttock and photoexposed dorsal forearm of young and ageing females with Fitzpatrick skin types II-III (n = 20) using histomorphic techniques. Whilst the minimum viable epidermis (Emin ) remained constant (Q > 0.05), the maximum viable epidermis (Emax ) was decreased by both age and photoexposure (Q ≤ 0.05), which suggests that differences in epidermal thickness are attributed to changes in the dermal-epidermal junction (DEJ). Changes in Emax were not affected by epidermal cell proliferation. For the first time, we investigated the basal keratinocyte morphology with age and photoexposure. Basal keratinocytes had an increased cell size, cellular height and a more columnar phenotype in photoexposed sites of young and ageing individuals (Q ≤ 0.05), however no significant differences were observed with age. Some of the most striking changes were observed in the DEJ, and a decrease in the interdigitation index was observed with both age and photoexposure (Q ≤ 0.001), accompanied by a decreased height of rête ridges and dermal papilla. Interestingly, young photoexposed skin was comparable to ageing skin across many parameters, and we hypothesise that this is due to accelerated photoageing. This study highlights the importance of skin care education and photoprotection from an early age.

Sex-specific differences in oxidative stress markers and collagen expression in perioral skin wrinkling.

Wrinkling is the hallmark of skin ageing. We previously reported that perioral wrinkling is more severe in females; however, the molecular basis is unknown. This study assessed sex differences in the molecular expression of key ageing regulators in perioral skin. Twelve subjects (n = 6 male/female) were enrolled in this cross-sectional study and biopsies were taken from the perioral and periocular regions. RNA expression of collagen I, collagen III, cysteine-rich angiogenic inducer 61 (CYR61) and insulin-like growth factor 1 (IGF-1) was assessed by qPCR. There was no difference between females' and males' Griffith's grades (6 and 5.67, respectively, p = 0.092) or periocular wrinkling grades (3.2 and 2.6, p = 0.421), but females had more severe perioral wrinkling grades than males (6.2 and 2.8, p = 0.020). Females not only expressed significantly more CYR61 (p = 0.018) in the perioral region than malesm but also expressed more collagen III (p = 0.016). There was no difference in collagen I (p = 0.115) or IGF-1 (p = 0.124) expression in the perioral region between sexes. In the periocular region, there were no significant differences between sexes in the expression of all four markers. The significant molecular differences in the perioral region between the sexes may contribute to the greater perioral skin wrinkling seen clinically in females.

Skin microbiome attributes associate with biophysical skin ageing.

Two major arms of skin ageing are changes in the skin's biophysical conditions and alterations in the skin microbiome. This work partitioned both arms to study their interaction in detail. Leveraging the resolution provided by shotgun metagenomics, we explored how skin microbial species, strains and gene content interact with the biophysical traits of the skin during ageing. With a dataset well-controlled for confounding factors, we found that skin biophysical traits, especially the collagen diffusion coefficient, are associated with the composition and the functional potential of the skin microbiome, including the abundance of bacterial strains found in nosocomial infections and the abundance of antibiotic resistance genes. Our findings reveal important associations between skin biophysical features and ageing-related changes in the skin microbiome and generate testable hypotheses for the mechanisms of such associations.

Male pattern hair loss: Can developmental origins explain the pattern?

Male pattern hair loss (MPHL), also referred to as male androgenetic alopecia (AGA) is the most common type of non-scarring progressive hair loss, with 80% of men suffering from this condition in their lifetime. In MPHL, the hair line recedes to a specific part of the scalp which cannot be accurately predicted. Hair is lost from the front, vertex, and the crown, yet temporal and occipital follicles remain. The visual effect of hair loss is due to hair follicle miniaturisation, where terminal hair follicles become dimensionally smaller. Miniaturisation is also characterised by a shortening of the growth phase of the hair cycle (anagen), and a prolongation of the dormant phase (kenogen). Together, these changes result in the production of thinner and shorter hair fibres, referred to as miniaturised or vellus hairs. It remains unclear why miniaturisation occurs in this specific pattern, with frontal follicles being susceptible while occipital follicles remain in a terminal state. One main factor we believe to be at play, which will be discussed in this viewpoint, is the developmental origin of the skin and hair follicle dermis on different regions of the scalp.

Skin ageing: Clinical aspects and in vivo microscopic patterns observed with reflectance confocal microscopy and optical coherence tomography.

Few studies have combined high-resolution, non-invasive imaging, such as standardized clinical images, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT), for age-related skin change characterization according to age groups. This study aimed to correlate clinical manifestations of ageing with skin cytoarchitectural background observed with high-resolution, non-invasive imaging according to age-related skin pattern distribution. A set of 140 non-pathological facial skin images were retrospectively retrieved from a research database. Subjects, aged between 20 and 89, were divided into 7 age groups. Clinical features were explored with VISIA, including hyperpigmentation, skin texture, wrinkles, pores and red areas, quantified and expressed as automated absolute scores. Previously described RCM and OCT epidermal and dermal features associated with ageing were investigated. All features were assessed for distribution and correlation among age groups. Significant direct correlations between age and clinical features were proven for cutaneous hyperpigmentation, skin texture, wrinkles and red areas. As age advances, RCM epidermal irregular honeycomb and mottled pigmentation are more frequently observed and collagen is more frequently coarse, huddled and curled, while the epidermis in OCT is thickened and the dermal density is decreased with more disrupted collagen fibres. RCM and OCT feature changes correlate directly and indirectly as well as correlating directly and indirectly with standardized clinical images. Clinical manifestations of ageing correlate with skin cytoarchitectural background observed with RCM and OCT. In conclusion, complimentary information between standardized clinical images and high-resolution, non-invasive imaging will assist in the development of future studies dedicated to skin ageing assessment and treatment effectiveness.

Application of Molecular Dynamics Simulations to Determine Interactions between Canary Seed (Phalaris canariensis L.) Bioactive Peptides and Skin-Aging Enzymes.

Food bioactive peptides are well recognized for their health benefits such as antimicrobial, antioxidant, and antihypertensive benefits, among others. Their drug-like behavior has led to their potential use in targeting skin-related aging factors like the inhibition of enzymes related with the skin-aging process. In this study, canary seed peptides (CSP) after simulated gastrointestinal digestion (<3 kDa) were fractioned by RP-HPLC and their enzyme-inhibition activity towards elastase and tyrosinase was evaluated in vitro. CSP inhibited elastase (IC50 = 6.2 mg/mL) and tyrosinase (IC50 = 6.1 mg/mL), while the hydrophobic fraction-VI (0.2 mg/mL) showed the highest inhibition towards elastase (93%) and tyrosinase (67%). The peptide fraction with the highest inhibition was further characterized by a multilevel in silico workflow, including physicochemical descriptor calculations, antioxidant activity predictions, and molecular dynamics-ensemble docking towards elastase and tyrosinase. To gain insights into the skin permeation process during molecular dynamics simulations, based on their docking scores, five peptides (GGWH, VPPH, EGLEPNHRVE, FLPH, and RPVNKYTPPQ) were identified to have favorable intermolecular interactions, such as hydrogen bonding of polar residues (W, H, and K) to lipid polar groups and 2-3 Å van der Waals close contact of hydrophobic aliphatic residues (P, V, and L). These interactions can play a critical role for the passive insertion of peptides into stratum corneum model skin-membranes, suggesting a promising application of CSP for skin-aging treatments.

[Geriatric dermatology]. / Geriatrische Dermatologie.

BACKGROUND: With an ageing society the incidences of skin diseases increase. OBJECTIVE: The most important skin diseases in geriatric patients are discussed. MATERIAL AND METHODS: A literature search was conducted using the PubMed database and standard dermatological textbooks. RESULTS: Skin diseases in geriatric patients are often more susceptible to external influences and can be affected by visceral diseases. Due to a delayed diagnosis, malignant skin diseases in geriatric patients are first diagnosed at a higher stage. CONCLUSION: Physiological skin changes are to be treated with appropriate care. In the case of unclear skin changes, a timely dermatological check-up is to be done.

Artificial Intelligence analysis of over half a million European and Chinese women reveals striking differences in the facial skin ageing process.

BACKGROUND: Artificial Intelligence (A.I) and deep learning-based algorithms are increasingly being used in dermatology following the emergence of powerful smartphones with high-resolution cameras. OBJECTIVES: To use an A.I-based algorithm, validated by dermatologists, to compare the evolution of the skin ageing process among Chinese and European women. METHODS: Selfie images were taken by 465 587 European and 79 016 Chinese women ranging from 18 to 85 and 18 to 69 years old, respectively, without facial skin diseases and who had access to a smartphone with a high-resolution camera (≥4 Megapixels). The selfies were analysed by facial skin diagnostic using a smartphone application to grade the severity of 9 facial signs (including wrinkles, sagging, vascular, pigmentation signs, pores). RESULTS: Wrinkles/texture, ptosis and sagging increased linearly with age in European women compared to lower scores and more gradual increase in the younger age-classes in Chinese women. In Chinese women, pigmentation signs increased regularly between 18 and 40 years, plateaued between 40 and 60 years, then increased in the over 60s compared to lower scores and a slower more regular increase with age in European women. Vascularization signs increased steadily with age in European women compared to no significant change in Chinese women. CONCLUSIONS: Marked differences were observed in the skin ageing process between European and Chinese populations, both in the prevalence of each facial ageing sign and their kinetics. Automatic grading performed on selfies and analysed by A.I is a fast and confidential method for quantifying signs of facial ageing and identifying the main issues for each population and age-class, which is of practical interest, as it will allow the development of tailored prevention and therapeutic measures.

Targeting Hydroxybenzoic Acids to Mitochondria as a Strategy to Delay Skin Ageing: An In Vitro Approach.

Targeting antioxidants to mitochondria is considered a promising strategy to prevent cellular senescence and skin ageing. In this study, we investigate whether four hydroxybenzoic acid-based mitochondria-targeted antioxidants (MitoBENs, MB1-4) could be used as potential active ingredients to prevent senescence in skin cells. Firstly, we evaluated the chemical stability, cytotoxicity, genotoxicity and mitochondrial toxicity of all compounds. We followed this by testing the antioxidant protective capacity of the two less toxic compounds on human skin fibroblasts. We then assessed the effects of the best hit on senescence, inflammation and mitochondrial remodeling on a 3D skin cell model, while also testing its mutagenic potential. Cytotoxicity and mitochondrial toxicity rankings were produced: MB3 < MB4 ≃ MB1 < MB2 and MB3 < MB1 < MB4 < MB2, respectively. These results suggest that pyrogallol-based compounds (MB2 and MB4) have lower cytotoxicity. The pyrogallol derivative, MB2, containing a 6-carbon spacer, showed a more potent antioxidant protective activity against hydrogen peroxide cytotoxicity. In a 3D skin cell model, MB2 also decreased transcripts related to senescence. In sum, MB2's biological safety profile, good chemical stability and lack of mutagenicity, combined with its anti-senescence effect, converts MB2 into a good candidate for further development as an active ingredient for skin anti-ageing products.

Nuclear factor-kappa B and effector molecules in photoaging.

Nuclear factor-kappa B (NF-κB) has important but complex functions in the photoaging of the human skin. This protein complex is activated upon UV irradiation and plays a key role in the signalling pathway of the inflammatory cascade. NF-κB induces the expression of various proinflammatory cytokines, such as tumour necrosis factor (TNF) and interleukin-1 (IL-1). These proinflammatory cytokines can in turn stimulate the activation of NF-κB, forming a vicious cycle. These processes cause chronic inflammation and contribute to skin ageing. In addition, the activation of NF-κB upregulates the expression of matrix metalloproteinases (MMPs) and leads to the degradation of structural proteins in the dermis. NF-κB disrupts the barrier function of the skin under prolonged and repeated UV stimulations in these ways. Such activity causes chronic skin damage, followed by the formation of wrinkles, dryness, roughness, laxity, and other photoaging manifestations. This study on the NF-κB signalling pathway and effector molecules provides a new perspective to understand and prevent photoaging.

Repetitive Daylight Photodynamic Therapy versus Cryosurgery for Prevention of Actinic Keratoses in Photodamaged Facial Skin: A Prospective, Randomized Controlled Multicentre Two-armed Study.

Actinic keratoses are a chronic condition in ultraviolet-damaged skin, with a risk of progressing to invasive skin cancer. The aim of this study was to investigate the preventive potential of field-directed repetitive daylight photodynamic therapy for actinic keratoses. A randomized trial was performed, including 58 patients with ≥5 actinic keratoses on photodamaged facial skin, who received either 5 full-face sessions of daylight photodynamic therapy within a period of 2 years or lesion-directed cryosurgery. Primary outcome was the mean cumulative number of new actinic keratoses developed between visits 2 and 6 (visit 6 being a follow-up). This outcome was lower after daylight photo-dynamic therapy (7.7) compared with cryosurgery (10.2), but the difference did not reach significance (-2.5, 95% confidence interval -6.2 to 1.2; p=0.18). Several signs of photoageing (fine lines, pigmentation, roughness, erythema, sebaceous gland hyperplasia) were significantly reduced after daylight photodynamic therapy, but not after cryosurgery. Significantly less pain and fewer side-effects were reported during daylight photodynamic therapy than during cryosurgery. This study found that repetitive daylight photodynamic therapy had photo-rejuvenating effects. However, the prevention of actinic keratoses by this therapy could not be proven in a statistically reliable manner.

Multi-wavelength, handheld laser speckle imaging for skin evaluation.

OBJECTIVE: A handheld device was developed and qualified for in vivo human skin evaluation using laser speckle imaging technology. METHODS: Each laser speckle device prototype allows the choice of up to three different laser wavelengths in the range of 400 nm to 800 nm in total. Speckle pattern analysis gives various speckle parameters, for example, speckle contrast, speckle size, speckle modulation or fractal dimension. The developed laser speckle device prototypes were evaluated investigating three skin issues. RESULTS: We receive reproducible results from the speckle imaging device. For skin ageing, we found significant changes within three age groups. The effect of a methyl nicotinate treatment was clearly visible and quantifiable using a moorFLPI device as well as our speckle imaging device. In terms of basal cell carcinoma diagnosis, we found significant differences between normal and diseased skin, even though the number of samples was limited. CONCLUSION: As shown with first application examples, it was possible to demonstrate the potential of the method for skin evaluation in vivo.

Cyanobacteria and microalgae bioactive compounds in skin-ageing: potential to restore extracellular matrix filling and overcome hyperpigmentation.

As the largest organ in human body, skin acts as a physicochemical barrier, offering protection against harmful environmental stressors, such as chemicals, pathogens, temperature and radiation. Nonetheless, skins prominence goes further, with a significant psychosocial role in an increasingly ageing population. Prompted by consumers' concern regarding skincare, cosmetic industry has been developing new formulas capable of lessening the most visible signs of ageing, including reduction in skin density and elasticity, wrinkling and hyperpigmentation. Allied to skincare is the rising importance set on natural products, sustainably obtained from less environmental impacting methods. Cyanobacteria and microalgae are adding importance in this field, given their ability to biosynthesize secondary metabolites with anti-ageing potential. In this review, we present an overview on the potential of cyanobacteria and microalgae compounds to overcome skin-ageing, essentially by exploring their effects on the metalloproteinases collagenase, elastase, gelatinase and hyaluronidase, and in other enzymes involved in the pigmentation process.

Towards data-driven quantification of skin ageing using reflectance confocal microscopy.

INTRODUCTION: Evaluation of skin ageing is a non-standardized, subjective process, with typical measures relying coarse, qualitatively defined features. Reflectance confocal microscopy depth stacks contain indicators of both chrono-ageing and photo-ageing. We hypothesize that an ageing scale could be constructed using machine learning and image analysis, creating a data-driven quantification of skin ageing without human assessment. METHODS: En-face sections of reflectance confocal microscopy depth stacks from the dorsal and volar forearm of 74 participants (36/18/20 training/testing/validation) were represented using a histogram of visual features learned using unsupervised clustering of small image patches. A logistic regression classifier was trained on these histograms to differentiate between stacks from 20- to 30-year-old and 50- to 70-year-old volunteers. The probabilistic output of the logistic regression was used as the fine-grained ageing score for that stack in the testing set ranging from 0 to 1. Evaluation was performed in two ways: on the test set, the AUC was collected for the binary classification problem as well as by statistical comparison of the scores for age and body site groups. Final validation was performed by assessing the accuracy of the ageing score measurement on 20 depth stacks not used for training or evaluating the classifier. RESULTS: The classifier effectively differentiated stacks from age groups with a test set AUC of 0.908. Mean scores were significantly different when comparing age groups (mean 0.70 vs. 0.44; t = -6.62, p = 0.0000) and also when comparing stacks from dorsal and volar body sites (mean 0.64 vs. 0.53; t = 3.12, p = 0.0062). On the final validation set, 17 out of 20 depth stacks were correctly labelled. DISCUSSION: Despite being limited to only coarse training information in the form of example stacks from two age groups, the trained classifier was still able to effectively discriminate between younger skin and older skin. Curiously, despite being only trained with chronological age, there was still evidence for measurable differences in age scores due to sun exposure-with marked differences in scores on sun-exposed dorsal sites of some volunteers compared with less sun-exposed volar sites. These results suggest that fine-grained data-driven quantification of skin ageing is achievable.

INTRODUCTION: L'évaluation du vieillissement de la peau est un processus subjectif et non standardisé, dont les mesures typiques reposent sur des caractéristiques grossières et définies qualitativement. Les strates de profondeur observées grâce à la microscopie confocale par réflectance contiennent des indicateurs de chrono-vieillissement et de photo-vieillissement. Nous émettons l'hypothèse selon laquelle il serait possible d'établir une échelle de vieillissement à l'aide de l'apprentissage automatique et de l'analyse d'images, permettant la mise en place d'une quantification du vieillissement cutané fondée sur les données et sans évaluation humaine. MÉTHODES: À l'aide d'un histogramme des caractéristiques visuelles apprises à partir de petits ensembles d'images regroupées sans supervision, on a représenté des coupes faciales de strates de profondeur observées grâce à la microscopie confocale par réflectance et issues des faces dorsale et palmaire de l'avant-bras de 74 participants (36/18/20 entraînement/analyse/validation). Après un processus d'entraînement portant sur ces histogrammes, un classificateur de régression logistique a appris à différencier les strates prélevées sur des volontaires âgés de 20 à 30 ans et celles prélevées sur des volontaires âgés de 50 à 70 ans. Le résultat probabiliste de la régression logistique a été utilisé comme score du vieillissement de haute précision, allant de 0 à 1, pour cette strate dans l'ensemble d'analyse. L'évaluation a été effectuée de deux manières : dans l'ensemble d'analyse, l'aire sous la courbe (ASC) a été identifiée pour le problème de classification binaire ainsi que par comparaison statistique des scores selon les tranches d'âge et les catégories de site corporel. La validation finale est passée par une évaluation de l'exactitude de la mesure du score de vieillissement sur 20 strates de profondeur non utilisées dans le cadre du processus d'entraînement ou d'évaluation du classificateur. RÉSULTATS: Le classificateur différenciait efficacement les strates des tranches d'âge, avec une ASC dans l'ensemble d'analyse de 0,908. Les scores moyens affichaient des différences significatives lors de la comparaison entre les tranches d'âge (moyenne de 0,70 contre 0,44 ; t = 6,62 ; p = 0,0000) et lors de la comparaison entre les strates issues des faces dorsale et palmaire des sites corporels (moyenne de 0,64 contre 0,53 ; t = 3,12 ; p = 0,0062). Dans l'ensemble de validation finale, 17 strates sur 20 ont été correctement classées.