Transepidermal Water Loss Research Articles

Propolis suppresses atopic dermatitis through targeting the MKK4 pathway.

Propolis is a natural resinous substance made by bees through mixing various plant sources. Propolis has been widely recognized as a functional food due to its diverse range of beneficial bioactivities. However, the therapeutic effects of consuming propolis against atopic dermatitis (AD) remain largely unknown. The current study aimed to investigate the potential efficacy of propolis against AD and explore the active compound as well as the direct molecular target. In HaCaT keratinocytes, propolis inhibited TNF-α-induced interleukin (IL)-6 and IL-8 secretion. It also led to a reduction in chemokines such as monocyte chemoattractant protein-1 (MCP-1) and macrophage-derived chemokine (MDC), while restoring the levels of barrier proteins, filaggrin and involucrin. Propolis exhibited similar effects in AD-like human skin, leading to the suppression of AD markers and the restoration of barrier proteins. In DNCB-induced mice, oral administration of propolis attenuated AD symptoms, improved barrier function, and reduced scratching frequency and transepidermal water loss (TEWL). In addition, propolis reversed the mRNA levels of AD-related markers in mouse dorsal skin. These effects were attributed to caffeic acid phenethyl ester (CAPE), the active compound identified by comparing major components of propolis. Mechanistic studies revealed that CAPE as well as propolis could directly and selectively target MKK4. Collectively, these findings demonstrate that propolis may be used as a functional food agent for the treatment of AD.

Short-term effect of a moderate-potency topical corticosteroid on epidermal biophysical parameters in patients with mild-to-moderate atopic dermatitis: A randomised controlled study.

Skin barrier dysfunction is an important component of atopic dermatitis (AD) pathophysiology. Topical corticosteroids (TCSs) are the mainstay therapy, but steroid phobia is emerging due to potential side effects. We aimed to determine the short-term effect of clobetasone butyrate on patients with AD. This investigator-blinded, randomised, moisturiser-controlled study evaluated patients with stable mild-to-moderate AD. Clobetasone butyrate ointment plus aqueous cream (Aq) or Aq alone was applied on randomised sites twice daily for 6 weeks. The itch score, modified Eczema Area and Severity Index (M-EASI) and epidermal biophysical parameters were assessed at baseline and 1 h, 3 h, 2 weeks and 6 weeks after application. Sixteen patients, among whom 14 (87.5%) were women and two (12.5%) were men, participated in the study. There were no significant differences in pH, transepidermal water loss (TEWL) and hydration between TCS + Aq and Aq from 1 h to 6 weeks. A non-significant trend of pH increment was observed with TCS + Aq from baseline to 6 weeks. TEWL and hydration improved at 6 weeks for both treatment arms. The difference in TEWL from baseline was significant with Aq (P=0.01). The M-EASI at 6 weeks was comparable between the two arms. TCS + Aq improved itch and erythema better than Aq (P=0.02). No cutaneous adverse effects were observed at both sites. Short-term application of clobetasone butyrate with Aq is safe with no significant changes in epidermal biophysical parameters while controlling the symptoms and signs of eczema faster than Aq alone.

Is It Possible to Monitor the Safest Time to Perform Secondary Surgery on Free Flaps? A Clinical Evaluation of the Tewameter®.

Background and Objectives: Postoperative monitoring, following free flap surgery, plays a crucial role in ensuring the survival of the flap. However, in microsurgery, not only the immediate postoperative monitoring period but also the choice of the right time for secondary surgeries is crucial for the free flap survival. There is no clear consensus concerning the right choice of timing for secondary surgery. Our aim was to evaluate transepidermal water loss (TEWL), with the objective evaluation tool Tewameter® in free flap surgery to monitor flap autonomization. Materials and Methods: Transepidermal water loss was assessed in 20 patients with microsurgically transplanted free anterior lateral thigh (ALTP) flaps. The transplantation of the ALTP-flap and the postoperative care were administered in accordance with the standard of care of the department. Measures were taken on the free flap and normal skin at follow-ups of 1, 3, and 6 months after initial free flap transplantation. Results: Transepidermal water loss gradually increased to the values found in normal skin, after 6 months. The differences between the two areas demonstrated the smallest variance after 6 months, specifically in the ALTP-flap region. The largest disparities were observed between month 1 and month 6, followed by month 3 and month 6, and month 1 and month 3. Conclusions: Free flap autonomization and physiology are complex processes. TEWL might be a valuable parameter to monitor flap autonomization. Our results indicate that TEWL in the free flap is nearly "normal" after six months. For a clear consensus of when to perform individual secondary surgery, further studies are needed.

Skin and Scalp Health Benefits of a Specific Botanical Extract Blend: Results from a Double-Blind Placebo-Controlled Study in Urban Outdoor Workers

Environmental pollution is increasingly recognized as a significant contributor to skin and scalp damage. Oral supplementation with a specific blend of four standardized botanical extracts (Rosmarinus officinalis, Lippia citriodora, Olea europaea leaf, and Sophora japonica) has been previously demonstrated to enhance skin health in individuals exposed to high environmental stress. Thus, it might represent a convenient strategy to also improve their scalp health aspect, particularly in subjects with sensitive scalps. To support these effects, a 12-week double-blind, randomized, placebo-controlled trial was performed in 66 women working outdoors in urban areas with high particulate matter (PM) levels and taking 250 mg of the botanical blend daily. Product efficacy was measured as follows: skin antioxidant status (FRAP); skin and scalp moisturization (corneometer), transepidermal water loss (tewameter), and oiliness (sebumeter); skin radiance and colour (spectrophotometer), elasticity and firmness (cutometer) and wrinkle depth (image analysis); and scalp clinical evaluation. Despite constant exposure to increased levels of PM, the tested product positively influenced all monitored parameters compared to both baseline and the placebo-treated group, in as early as 4 weeks. At the end of the study, key improvements included increased skin FRAP (21.9%), moisturization (9.5%), radiance (24.9%) and reduced wrinkle depth (−16.5%), dark spot pigmentation (−26.2%), and skin oiliness (−19.3%). For the scalp, moisturization increased (14.1%), TEWL decreased (−13.8%), and sebum content reduced by 16.2%. Additionally, 71% of subjects with sensitive scalps experienced reduced redness. These findings highlight the extensive benefits of the ingredient, expanding its application beyond conventional skin treatments to also alleviate scalp issues.

Overexpression of the β-Subunit of Acid Ceramidase in the Epidermis of Mice Provokes Atopic Dermatitis-like Skin Symptoms.

We previously reported that a pathogenic abnormality in the barrier and water-holding functions of the stratum corneum (SC) in the skin of patients with atopic dermatitis (AD) is mainly attributable to significantly decreased levels of total ceramides in the SC. That decrease is mediated by the abnormal expression of a novel ceramide-reducing enzyme, sphingomyelin/glucosylceramide deacylase (SGDase), which is the β-subunit (ASAH1b) of acid ceramidase. In this study, we determined whether mice overexpressing ASAH1b in their epidermis develop AD-like skin symptoms. We generated transgenic (TG) mice overexpressing ASAH1b, regulated by the involucrin promoter, to localize its expression in the upper epidermis. After hair removal using a depilatory cream containing glycolic acid, the TG mice without any visible skin inflammation at 8 weeks of age had increased levels of ASAH1b and decreased levels of SC ceramide, with disrupted barrier functions measured by trans-epidermal water loss compared to the wild-type (WT) mice. Interestingly, enzymatic assays revealed that SGDase activity was not detectable in the skin of the TG mice compared to WT mice. Immunological staining revealed that there was an increased expression level of IL-33 in the epidermis and an accumulation of macrophages in the dermis of TG mice compared to WT mice, which are phenotypic characteristics of AD, that were exacerbated by tape-stripping of the skin. In the skin of the TG mice, the mRNA levels of IL-5, CCL11, IL-22, CXCL10, and IFNγ were significantly upregulated compared to the WT mice, and tape-stripping significantly increased the mRNA levels of IL-4, IL-33, CXCL1, CXCL12, TLR9, and CD163 compared to WT mice. These findings strongly indicate that the skin of the depilatory cream-treated TG mice exists in an atopic dry skin condition that is highly sensitive to various environmental stimuli. The sum of our results suggests that ASAH1b itself, even in the absence of its enzymatic activity, is a major etiologic factor for atopic dry skin symptoms via an unknown mechanism.

In vitro, exvivo, instrumental and clinical evaluation of atopical cream on the signs of periorbital ageing.

Periorbital skin ageing signs are multidimensional, highly visible and a concern for many. We evaluated the potential efficacy of an eye cream to diminish these signs. Biological markers associated with ageing, barrier function and homeostasis were analysed invitro to determine the effects of topically applied eye cream, compared to those of a placebo using human skin tissue models and/or explants. Collagen IV, elastin and bone morphogenic protein 4 (BMP4) expression was investigated by immunohistochemical labelling, while filaggrin, kallikrein 7 (KLK7) and HB-EGF were evaluated by RT-qPCR. IL-1α and melanin levels in darkly pigmented skin models were also quantified. The protective effect of the cream on glycation was assessed by a non-enzymatic assay. Finally, the benefits of twice-daily applications of the eye cream for 56 days were instrumentally and clinically evaluated on 33 women. Only the eye cream, not the placebo, stimulated collagen IV and BMP4 protein expression, as well as increased elastin fibre length. It also led to higher HB-EGF, filaggrin and KLK7 mRNA levels. The placebo and the eye cream did not induce changes in IL-1α and melanin levels, but both reduced non-enzymatic glycation. When assessing the invivo effects of the cream, short-term results indicated skin hydration, transepidermal water loss (TEWL) and skin profilometry improvement within 15 min. Instrumental evaluations of wrinkles showed a reduction after 7 days, which was clinically perceivable after 28 or 56 days. The eye-opening angle and eyelid sagging also improved after seven and 28 days, respectively. Finally, dark circles became lighter within 7 days (instrumental measurement) or 28 days (clinical assessment). The instrumental and clinical evaluations revealed that the eye cream reduced all periorbital ageing signs evaluated. Its effects are supported by the invitro and exvivo analyses of molecular markers.

Skin barrier, phenotypic and genotypic characterisation of autosomal recessive ichthyosis in TGM1-deficient Jack Russell Terriers and response to topical ceramide.

Autosomal recessive ichthyosis leads to structural or biochemical changes that impair skin barrier function. To assess (1) the phenotype and genotype in a litter of Jack Russell Terriers with autosomal recessive congenital ichthyosis (ARCI), and (2) the defective skin barrier and determine if a topical ceramide can modulate the barrier. A healthy dam and litter of Jack Russell Terrier puppies (healthy male, affected male and female), one affected adult Jack Russell Terrier and one unrelated healthy Jack Russell Terrier. A severe cornification defect was identified via examination of affected puppies. As the phenotype worsened, the affected puppies received a topical application of ω-0-acylceramide for 10 days. Before humane euthanasia, the skin barrier was evaluated via transepidermal water loss (TEWL), corneometry and pH in affected dogs. Genomic testing was performed, and skin samples were analysed by light and electron microscopy. Affected puppies were homozygous for the 1980 bp LINE-1 insertion in the TGM1 (transglutaminase 1) gene; the unaffected littermate and the dam were heterozygous carriers. ARCI puppies were underweight and had a severe hyperkeratotic phenotype that impaired mobility. TEWL was markedly higher in affected dogs. The cutaneous pH of affected puppies was higher than the normal littermate. Treatment of the skin with ω-0-acylceramide normalised the pH to match the littermate and decreased TEWL. Electron microscopy revealed marked attenuation of the cornified envelope. Dogs with TGM1-deficient ARCI have an impaired skin barrier. Topical therapy can partially repair the barrier defect.

Improvement effects of tapinarof on the skin barrier function in Japanese patients with atopic dermatitis

Background: Tapinarof is a nonsteroidal, topical, aryl hydrocarbon receptor agonist. Tapinarof has been shown to be efficacious and have acceptable safety profile in the treatment of atopic dermatitis (AD).Objective: We sought to evaluate the improvement effect of tapinarof on skin barrier function in patients with AD.Methods: This was an open-label, uncontrolled, single-center study. Japanese patients aged ≥20 years with AD (N = 30) were included in this study. Patients applied tapinarof cream 1% once daily to the target areas on the volar forearm for 8 weeks. The primary endpoints were changes from baseline in stratum corneum hydration (SCH) and transepidermal water loss (TEWL) at the target affected area at week 8.Results: The mean SCH value at the target affected area was 13.656 AU at baseline, 16.904 AU at week 4, and 16.423 AU at week 8. The SCH at the target affected area significantly increased from baseline to week 8, with a mean change of 2.826 AU (p = 0.0433). The mean TEWL value at the target affected area was 17.35 g/m2/hr at baseline, 10.01 g/m2/hr at week 4, and 9.52 g/m2/hr at week 8. The TEWL at the target affected area significantly decreased from baseline to week 8, with a mean change of −8.03 g/m2/hr (p < 0.0001). Clinical signs of AD at the target affected area were improved over time. No serious, severe, or treatment-related AEs were reported.Conclusion: Treatment with tapinarof led to an increase in SCH and a decrease in TEWL in patients with AD, indicating the potential improvement effect of tapinarof on skin barrier function.

Holistic investigation of the anti-wrinkle and repair efficacy of a facial cream enriched with C-xyloside.

To investigate the repairing and anti-wrinkle efficacy of the facial cream enriched with C-xyloside, aiming at comprehensively evaluating its skin anti- aging effect and clarify its potential mechanism of action. The repairing efficacy was studied on 3D epidermis skin model and the antiaging efficacy was studied on ex-vivo human skin. Two clinical studies were conducted with Chinese females. In the first study, 49 subjects aged between 30 and 50 with wrinkle concerns were recruited and instructed to apply the investigational cream containing C-xyloside for 8 weeks. Wrinkles attributes were assessed by dermatologist. Instrumental measurements on skin hydration, trans-epidermal water loss (TEWL), and skin elasticity were also conducted. In the second study, 30 subjects aged between 25 and 60 with self-declared sensitive skin and facial redness were recruited and instructed to apply the cream for 4 weeks. Biomarker analysis of the stratum corneum was conducted through facial tape strips. The cream improved the histomorphology of the 3D epidermis skin model after SLS stimulation, and significantly increase the expression of LOR and FLG. On human skin, the cream improved the histopathology induced by UV, and significantly increased the protein content of COL I and COL III, collagen density and the number of Ki-67 positive cell of skin compared with model group (n = 3, p < 0.01). The results from the first clinical study demonstrate a significant increased the skin hydration and elasticity by 21.90%, 13.08% (R2) and 12.30% (R5), respectively (n = 49, p < 0.05), and the TEWL values decreased by 33.94% (n = 49, p < 0.05), after 8 weeks application of the cream. In addition, the scores for nasolabial folds, glabellar wrinkle, underneath eye wrinkles, crow's feet wrinkle and forehead wrinkle in the volunteers exhibited a significant reduction of 34.02%, 43.34%, 50.03%, 33.64% and 55.81% respectively (n = 49, p < 0.05). The (rCE)/(fCE) ratio of volunteers based on tape stripping significant increased after using the sample cream (n = 30, p < 0.05). The cream containing C-xyloside showed improvement of skin wrinkles and enhancement of skin barrier function. These efficacies may be attributed to the fact that the sample cream can increase the expression of skin barrier related proteins LOR and FLG, promote the maturation of cornified envelope, enhance collagen I and III protein expression and stimulate skin cell proliferation, to provide sufficient evidence supporting its antiaging efficacy of skin.

Molybdenum Nanoparticles Alleviate MC903-Induced Atopic Dermatitis-Like Symptoms in Mice by Modulating the ROS-Mediated NF-κB and Nrf2 /HO-1 Signaling Pathways.

Atopic dermatitis (AD) is a chronic inflammatory skin condition that can affect individuals of all ages. Recent research has shown that oxidative stress plays a crucial role in the development of AD. Therefore, inhibiting oxidative stress may be an effective therapeutic approach for AD. Nano-molybdenum is a promising material for use as an antioxidant. We aimed to evaluate the therapeutic effects and preliminary mechanisms of molybdenum nanoparticles (Mo NPs) by using a murine model of chemically induced AD-like disease. HaCaT cells, a spontaneously immortalized human keratinocyte cell line, were stimulated by tumor necrosis factor-alpha /interferon-gamma after pre-treatment with Mo NPs. Reactive oxygen species levels, production of inflammatory factors, and activation of the nuclear factor kappa-B and the nuclear factor erythroid 2-related factor pathways were then evaluated. Mo NPs was topically applied to treat a murine model of AD-like disease induced by MC903, a vitamin D3 analog. Dermatitis scores, pruritus scores, transepidermal water loss and body weight were evaluated. AD-related inflammatory factors and chemokines were evaluated. Activation of the nuclear factor kappa-B and nuclear factor erythroid 2-related factor / heme oxygenase-1 pathways was assessed. Our data showed that the topical application of Mo NPs dispersion could significantly alleviate AD skin lesions and itching and promote skin barrier repair. Further mechanistic experiments revealed that Mo NPs could inhibit the excessive activation of the nuclear factor kappa-B pathway, promote the expression of nuclear factor erythroid 2-related factor and heme oxygenase-1 proteins, and suppress oxidative stress reactions. Additionally, they inhibited the expression of thymic stromal lymphopoietin, inflammatory factors, and chemokines, thereby alleviating skin inflammation. Mo NPs present a promising alternative treatment option for patients with AD as they could address three pivotal mechanisms in the pathogenesis of AD concurrently.

What defines dry skin? Correlating a range of skin hydration parameters with InVivo Confocal Raman Spectroscopy.

While there are a wide range of approaches for the assessment of skin hydration, it is not always clear how data from them relate to one another or to the skin itself. With the development of invivo Confocal Raman Spectroscopy (ICRS), it has become possible to measure water concentration as a function of protein/depth within the stratum corneum (SC). This article reports a comparison between electrical skin hydration measures/visual/optical grading and water concentration profiles measured using ICRS, to better understand the relationship between these approaches. SC hydration of lower-leg skin with varying degrees of dryness was assessed using visual grading (live and from digital images), Corneometer®, Visioscan and ICRS. In addition, a custom fingerprint sensor was used to image surface capacitance (as a surrogate of SC hydration), and SC barrier function was assessed using evaporimetry (to measure trans-epidermal water loss; TEWL). Significant correlations were observed between a number of different skin grading/measurement approaches and ICRS data. ICRS hydration profiles also revealed a region near the SC surface with a relatively flat water profile in dry skin subjects. The advent of quantitative invivo analytical techniques such as ICRS, which can be used in a clinical setting, has enabled greater insight into more conventional approaches for assessing skin dryness. While traditional skin grading and biophysical methods for measuring skin hydration have varying degrees of correlation with one another, they also provide comparatively unique information about different regions within the SC. This should enable a more informed approach to product development in the future.

Impact of multilamellar formulations on stratum corneumlipid organization and epidermal lipid barrier enhancement (Part II).

The integrity of the stratum corneum (SC) is crucial for the skin's barrier function, protecting against environmental stressors and minimizing transepidermal water loss. Advances in skincare formulations have introduced multilamellar systems designed to emulate the SC's lipid composition and organization. This study hypothesizes that the application of a multilamellar cream will significantly impact the SC's lipid content and lamellar structure, thereby enhancing the epidermal barrier. A saturated phosphatidylcholine-based multilamellar cream was applied to a cohort of adult subjects with very dry skin. Electron microscopy was utilized to analyse the micro-morphology of the cream and its integration into the lipid-depleted SC. Lipid analysis was conducted to quantify changes in the intercellular lipid matrix. Transmission-electron microscopy (TEM) imaging demonstrated that the multilamellar cream possesses a structured arrangement comparable to the natural SC architecture. Short-term application revealed a time-dependent restoration of lipid bilayers, while a 14-day regimen showed a marked increase in lipid lamellae density and length within the SC. Lipid analysis indicated a significant increase in total lipid content, with notable enhancements in ceramide and free fatty acid levels, without altering cholesterol levels. Lipid ratio analysis further confirmed the rebalancing of the SC's lipid composition. The multilamellar cream selectively increased specific lipids critical for barrier function, suggesting an action mechanism that aligns with the skin's natural regulatory processes. This selective augmentation indicates the potential of the formulation to not only restore but also enhance the epidermal barrier, with the maintenance of physiological lipid ratios suggesting compatibility with intrinsic repair mechanisms. The study confirms that a multilamellar cream can significantly improve the SC's lipid composition and structural integrity, indicating enhanced barrier function. They are pivotal for skincare professionals, dermatologists, and product developers, enriching the understanding of multilamellar creams' benefits and applications in improving epidermal barrier function.

IMPACT OF GENDER DIFFERENCES AND BODY MASS INDEX ON SKIN BIOPHYSICAL PARAMETERS OF CORONAVIRUS PATIENTS

Once the pandemic started, there were no clues regarding overall COVID-19 infections. There are no studies that demonstrate the effects of COVID-19 on skin surface pH, moisture, sebum, and temperature in terms of gender differences and body mass index (BMI) among infected people. The goal of this study was to investigate some of the skin biophysical scores of patients infected with COVID-19 and evaluate the impact of gender differences and the body mass index on them. Skin surface sebum, pH, temperature, and hydration (moisture), were measured in 30 COVID-19 patients using employing non-invasive portable devices. Insignificant effects of gender differences and BMI on skin biophysical properties were observed. In addition, females showed higher skin biophysical characteristics than males. Moreover, obese patients had higher skin biophysical parameter values than normal-weight patients. However, all the study results were statistically insignificant (p &gt; 0.05). Further investigations are required to recognize other skin biophysical parameters such as transepidermal water loss and elasticity that may aid in the early identification of skin damage in COVID-19 patients.

Papain Suppresses Atopic Skin Inflammation through Anti-Inflammatory Activities Using In Vitro and In Vivo Models.

Papain (PN) is a proteolytic enzyme derived from Carica Papaya L. While the pharmacological effects of PN have not been extensively studied compared to its enzymatic activity, PN also holds potential benefits beyond protein digestion. This study aimed to investigate the potential effects of PN against skin inflammation in house dust mite Dermatophagoides farinae body (Dfb)-exposed NC/Nga atopic dermatitis (AD) mice and human HaCaT keratinocytes and their underlying mechanisms. The effects of PN on the skin were assessed via histological examination, measurements of transepidermal water loss (TEWL), quantitative reverse transcription-polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. Our findings indicated that the oral intake of PN decreased the severity scores of lesions resembling AD, TEWL, and the levels of inflammatory cytokines and serum immunoglobulin E in Dfb-induced AD mice, along with a reduction in epidermal thickness and mast cell infiltration. Additionally, PN inhibited the activation of the mitogen-activated protein kinases (MAPKs) and the signal transducer and activator of transcription (STAT) pathways in Dfb-induced AD mice and HaCaT keratinocytes. Moreover, PN improved survival and reduced ROS production in H2O2-damaged HaCaT keratinocytes and enhanced the expression of antioxidant enzymes in Dfb-induced AD mice. Concludingly, the oral administration of PN suppressed inflammatory mediators and downregulated the MAPKs/STAT pathway, suggesting its potential role in AD pathogenesis.

Construction of a mouse model for sensitive skin research.

Current animal models of sensitive skin do not adequately reflect the objective symptoms or physiological manifestations observed in human sensitive skin. To construct and validate a sensitive skin model in mice. Tape stripping (TS) was used to induce partial mechanical disruption of the lipid film and stratum corneum. Subsequently, propylene glycol (PG) was applied to disrupt the lipid structure in the skin barrier, and capsaicin (CS) activate transient receptor potential vanilloid 1 (TRPV1) receptors of keratinocytes to simulate the formation of sensitive skin. Evident itching and tingling sensations, scaly skin, vasodilation, local congestion, increased transepidermal water loss (TEWL), elevated TRPV1 expression, and inflammatory symptoms were subsequently evaluated. TS combined with PG and CS application resulted in skin flakes; skin barrier disruption; vascular dilation; increased itching, stinging, and inflammation; TRPV1 upregulation in the epidermis; and a significant increase in lactic acid-induced itching and stinging. Using a combination of TS and PG, and CS application, a mouse model of sensitive skin was successfully established involving various skin phenotypes and physiological manifestations, including skin flakes, vasodilation, increased blood flow and TEWL, itching and stinging sensations, inflammation, and elevated TRPV1 expression.

Antibacterial and Immunosuppressive Effects of a Novel Marine Brown Alga-Derived Ester in Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic skin condition that is characterized by dysregulated immune responses and a heightened risk of Staphylococcus aureus infections, necessitating the advancement of innovative therapeutic methods. This study explored the potential of (6Z,9Z,12Z,15Z)-(2R,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl octadeca-6,9,12,15-tetraenoate (HSN-S1), a compound derived from the marine alga Hizikia fusiformis, which shows anti-inflammatory, antimicrobial, and immunomodulatory properties. HSN-S1 was isolated and characterized using advanced chromatographic and spectroscopic methods. Its efficacy was evaluated via in vitro assays with keratinocytes, macrophages, and T cells to assess cytokine suppression and its immunomodulatory effects; its antibacterial activity against S. aureus was quantified. The in vivo effectiveness was validated using a 2,4-dinitrochlorobenzene-induced AD mouse model that focused on skin pathology and cytokine modulation. HSN-S1 significantly reduced pro-inflammatory cytokine secretion, altered T-helper cell cytokine profiles, and showed strong antibacterial activity against S. aureus. In vivo, HSN-S1 alleviated AD-like symptoms in mice and reduced skin inflammation, transepidermal water loss, serum immunoglobulin-E levels, and Th2/Th17 cytokine outputs. These findings suggest HSN-S1 to be a promising marine-derived candidate for AD treatment, as it offers a dual-target approach that could overcome the limitations of existing therapies, hence warranting further clinical investigation.

The evidence from in vitro primary fibroblasts and a randomized, double-blind, placebo-controlled clinical trial of tuna collagen peptides intake on skin health.

Collagen peptides from various sources demonstrate benefits in health and well-being both in vitro and in clinical trials. However, there is a scarce study of collagen peptides from Tuna on skin health. To investigate the impact of collagen peptides derived from Tuna (Katsuwonus pelamis and Thunnus albacares) on skin health, utilizing in vitro biological studies and a randomized controlled trial. In vitro biological studies on human dermal primary fibroblasts were evaluated in terms of collagen and elastin synthesis and senescent cell inhibition. A randomized, placebo-controlled, double-blind clinical trial was conducted on 72 women who were randomly assigned to receive either tuna collagen peptides (n = 36) or a placebo (n = 36) orally for 8 weeks and 2 weeks post-ingestion by measuring skin hydration, transepidermal water loss (TEWL), skin elasticity, and skin density. In vitro biological effects demonstrated dose-dependent positive results in increasing collagen and elastin synthesis and reducing senescent cells. The effects on collagen and senescent cells plateaued at high concentrations. A clinical trial showed that the test group experienced a significant increase in skin hydration, elasticity, and density, along with a decrease in TEWL compared to the baseline. The test and placebo groups showed statistically significant differences at 8 weeks for all parameters except for the TEWL at the face. All positive effects were substantially retained even after 2 weeks of discontinuation. These findings demonstrate the significant potential of tuna collagen peptides to promote human skin health, warranting further investigation as a potential nutraceutical.

Correlations between Skin Condition Parameters and Ceramide Profiles in the Stratum Corneum of Healthy Individuals.

Ceramides are essential lipids for skin barrier function, and various classes and species exist in the human stratum corneum (SC). To date, the relationship between skin conditions and ceramide composition in healthy individuals has remained largely unclear. In the present study, we measured six skin condition parameters (capacitance, transepidermal water loss, scaliness, roughness, multilayer exfoliation, and corneocyte cell size) for the SC of the cheeks and upper arms of 26 healthy individuals and performed correlation analyses with their SC ceramide profiles, which we measured via liquid chromatography-tandem mass spectrometry. In the cheeks, high levels and/or ratios of two free ceramide classes containing an extra hydroxyl group in the long-chain moiety and a protein-bound ceramide class containing 6-hydroxysphingosine correlated with healthy skin conditions. In contrast, the ratios of two other free ceramide classes, both containing sphingosine, and a protein-bound ceramide class containing 4,14-sphingadiene correlated with unhealthy skin conditions, as did shortening of the carbon chain of the fatty acid portion of two ceramide classes containing non-hydroxy fatty acids. Thus, our findings help to elucidate the relationship between skin conditions and ceramide composition.

Study on percutaneous penetration of representative cosmetic ingredients in a baby wipe product in an in vitro diaper rash skin model

Studying percutaneous penetration of various cosmetic ingredients through intact and compromised skin can provide insight on quantitative exposure assessment for baby products intended for diapered skin. We developed an in vitro model (tape-stripped human skin) designed to achieve the Trans-Epidermal Water Loss values measured in babies with various degrees of diaper dermatitis. Six reference compounds showed the impact of physicochemical properties on absorption through this “diaper rash” skin model. Under simulated diaper conditions, dermal absorption of cosmetic ingredients (phenoxyethanol, sodium benzoate, benzyl alcohol, disodium EDTA, and propylene glycol) was different, but <100%. Additionally, the effect of diaper rash on dermal absorption of well-absorbed ingredients (phenoxyethanol, sodium benzoate, and benzyl alcohol) was limited (enhancement of 1.1–1.3), while the enhancement for moderately absorbed compounds (disodium EDTA and propylene glycol) was 1.8–3.3. Absorption via skin with “diaper rash” is specific to individual ingredients and exposure conditions, so a fixed uncertainty factor is not appropriate for safety assessment. The data support that the default 100% dermal absorption commonly used in first-tier risk assessments for diapered skin is conservative. This diaper rash skin model provides a practical tool of estimating absorption of various ingredients in baby products intended for diapered skin.

Efficacy and Safety Assessment of Topical Omega Fatty Acid Product in Experimental Model of Irritant Contact Dermatitis: Randomized Controlled Trial

Contact dermatitis is a common inflammatory skin disease that often requires prescription therapy and is associated with adverse reactions. Omega fatty acids have been recognized for their anti-inflammatory effect and could serve as a safer option in contact dermatitis treatment. Therefore, the aim of this randomized controlled study, conducted at the University of Split School of Medicine, was to evaluate the efficacy and safety of omega fatty acids containing topical products in an experimental model of irritant contact dermatitis. This study was registered with ClinicalTrials (NCT06189144) and is closed. The primary outcomes were levels of transepidermal water loss, skin hydration, and skin erythema, all measured using an MPA6 device in 25 healthy participants. A significant difference was observed between the hydration values of the intervention (45.7 ± 12.4) and control groups (31.6 ± 12.3) (p &lt; 0.05) on final measurements (day 10). Moreover, higher erythema levels were observed in participants who were smokers, compared to non-smokers. No adverse drug reactions were observed during the study period. In conclusion, omega fatty acids topical product use shows promise in the treatment of irritant contact dermatitis, and further studies are needed to evaluate efficacy in a larger sample of patients.