Antibacterial toner exhibits bactericidal effect against Cutibacterium acnes via keratin and sebum plug penetration.

Cutibacterium acnes is an opportunistic pathogen recognized as a contributing factor to acne vulgaris. The accumulation of keratin and sebum plugs in hair follicles facilitates C. acnes proliferation, leading to inflammatory acne. Although numerous antimicrobial cosmetic products for acne-prone skin are available, their efficacy is commonly evaluated against planktonic cells of C. acnes. Limited research has assessed the antimicrobial effects on microorganisms within keratin and sebum plugs. This study investigates whether an antibacterial toner can penetrate keratin and sebum plugs, exhibiting bactericidal effects against C. acnes. Scanning electron microscopy and next-generation sequencing analysis of the keratin and sebum plug suggest that C. acnes proliferate within the plug, predominantly in a biofilm-like morphology. To clarify the potential bactericidal effect of the antibacterial toner against C. acnes inside keratin and sebum plugs, we immersed the plugs in the toner, stained them with LIVE/DEAD BacLight Bacterial Viability Kit to visualize microorganism viability, and observed them using confocal laser scanning microscopy. Results indicate that most microorganisms in the plugs were killed by the antibacterial toner. To quantitatively evaluate the bactericidal efficacy of the toner against C. acnes within keratin and sebum, we immersed an artificial plug with inoculated C. acnes type strain and an isolate collected from acne-prone skin into the toner and obtained viable cell counts. The number of the type strain and the isolate inside the artificial plug decreased by over 2.2 log and 1.2 log, respectively, showing that the antibacterial toner exhibits bactericidal effects against C. acnes via keratin and sebum plug penetration.

Research progress on the role of macrophages in acne and regulation by natural plant products.

Acne vulgaris is one of the most common skin diseases. The current understanding of acne primarily revolves around inflammatory responses, sebum metabolism disorders, aberrant hormone and receptor expression, colonization by Cutibacterium acnes, and abnormal keratinization of follicular sebaceous glands. Although the precise mechanism of action remains incompletely understood, it is plausible that macrophages exert an influence on these pathological features. Macrophages, as a constituent of the human innate immune system, typically manifest distinct phenotypes across various diseases. It has been observed that the polarization of macrophages toward the M1 phenotype plays a pivotal role in the pathogenesis of acne. In recent years, extensive research on acne has revealed an increasing number of natural remedies exhibiting therapeutic efficacy through the modulation of macrophage polarization. This review investigates the role of cutaneous macrophages, elucidates their potential significance in the pathogenesis of acne, a prevalent chronic inflammatory skin disorder, and explores the therapeutic mechanisms of natural plant products targeting macrophages. Despite these insights, the precise role of macrophages in the pathogenesis of acne remains poorly elucidated. Subsequent investigations in this domain will further illuminate the pathogenesis of acne and potentially offer guidance for identifying novel therapeutic targets for this condition.

Safety, Efficacy and Attributes of 2.5% Selenium Sulfide Shampoo in the Treatment of Dandruff: A Single-Center Study.

BACKGROUND: Selenium sulfide, available as a shampoo or topical lotion at 1%, or 2.5% concentrations in India, is used as a topical antiseborrheic and antifungal for the treatment of dandruff, seborrheic dermatitis, psoriasis, and tinea versicolor. In the present study, the safety, efficacy, and attributes of 2.5% selenium sulfide shampoo were evaluated in Indian participants with dandruff. METHODS: A single-center, single-arm, prospective, investigator-initiated, open-label, post-marketing interventional study was conducted on Indian subjects aged 18-70 years diagnosed with moderate dandruff who were prescribed 2.5% selenium sulfide shampoo every three days for four weeks. The primary endpoints were 1) reduction in total dandruff score assessed using a clinical grading scale for adherent and loose dandruff from baseline to weeks 1, 2, and 4, and 2) incidence of adverse events up to the end of the study. The key secondary endpoints were 1) participants' perception of shampoo attributes (dandruff reduction, scalp itch, scalp oiliness/greasiness, or fragrance) as assessed by a subjective self-assessment questionnaire post-first wash and at weeks 1, 2, and/or 4; 2) satisfaction with treatment as assessed by investigators and participants using a subjective self-assessment questionnaire at week 4; and 3) reduction in scalp sebum as assessed with a meibometer at weeks 2 and 4. Statistical analysis was performed using the Wilcoxon signed-rank test for continuous variables and the Chi-square test for categorical variables. A p-value of 0.05 was considered to be statistically significant. RESULTS: Of 34 enrolled subjects, 30 completed the four-week study. The mean (standard deviation, SD) age of the study participants was 29.8 (7.87) years, with the majority being females (n=18; 60.0%). Mean (SD) total dandruff score significantly (p=0.001) reduced from a baseline score of 11.5 (2.15) to 7.17 (2.12) at week 1, 4.93 (1.72) at week 2, and 2.5 (1.17) at week 4. All the participants reported dandruff reduction and acceptable fragrance of the shampoo at four weeks. Absence of itching and reduction in oiliness was reported by 73.3% (n=22) of participants at week 4 and by 50.0% (n=15) of participants at week 2, respectively. All participants reported good, very good, or excellent satisfaction with the test shampoo at week 4, whereas the investigators rated the shampoo as very good or excellent in managing dandruff in all participants. At week 4, erythema was reported to be absent in all participants. No adverse events were reported during the study. CONCLUSIONS: The 2.5% selenium sulfide shampoo was found to be effective in the management of dandruff and related symptoms like itching, oiliness, and greasiness and had a good safety profile in Indian participants with dandruff.

Microemulsions and Nanoemulsions for Topical Delivery of Tripeptide-3: From Design of Experiment to Anti-Sebum Efficacy on Facial Skin.

The targeted delivery of a hydrophilic Tripeptide-3 to the skin using microemulsions or nanoemulsions for facial oil reduction was the focus of this study. The impact factors affecting oil/water transparent dispersion formation, such as the surfactant system, HLB value, and co-solvent, were identified through the water titration method and pseudoternary phase diagram plots. The interfacial tension between caprylic/capric triglyceride (CCT oil) and water was significantly reduced by the surfactant/co-surfactant combination (Smix) of Cremophore® RH40 and a double-tails co-surfactant, polyglycerol-3-diisostearate, at an HLB of 13 together with a water-to-co-solvent (PG) ratio of 1:1. A two-level full factorial design of experiment (FFD-DoE) emphasized the independent variables of the HLB value, co-solvent, and CCT oil contents affecting the optimal compositions for micro- or nanoemulsion formation. The low-energy spontaneous emulsification of the optimized combination at a low Smix content (10%) yielded the translucent oil-in-water Tripeptide-3 nanoemulsions with an internal droplet size of 25.7 ± 1.20 nm, a narrow polydispersity index of 0.237 ± 0.129, and 70.6 ± 0.58% transmittance. The in vitro skin permeation study revealed a significantly higher skin penetration and retention of the Tripeptide-3 nanoemulsions compared to the high surfactant microemulsions and coarse emulsions. Skin irritation and oil control efficacy were evaluated in healthy volunteers before and after product application for 28 days. The obtained nanoemulsions not only decreased sebum production but also enhanced skin moisture levels. In conclusion, the meticulously designed nanoemulsions, incorporating suitable excipients, show a promising delivery system for hydrophilic peptides to control sebum overproduction in oily facial skin.

Comparative Characterization of Human Meibomian Glands, Free Sebaceous Glands, and Hair-Associated Sebaceous Glands Based on Biomarkers, Analysis of Secretion Composition, and Gland Morphology.

Meibomian gland dysfunction (MGD) is one of the main causes of dry eye disease. To better understand the physiological functions of human meibomian glands (MGs), the present study compared MGs with free sebaceous glands (SGs) and hair-associated SGs of humans using morphological, immunohistochemical, and liquid chromatography-mass spectrometry (LCMS)-based lipidomic approaches. Eyelids with MGs, nostrils, lips, and external auditory canals with free SGs, and scalp with hair-associated SGs of body donors were probed with antibodies against cytokeratins (CK) 1, 8, 10, and 14, stem cell markers keratin 15 and N-cadherin, cell-cell contact markers desmoglein 1 (Dsg1), desmocollin 3 (Dsc3), desmoplakin (Dp), plakoglobin (Pg), and E-cadherin, and the tight junction protein claudin 5. In addition, Oil Red O staining (ORO) was performed in cryosections. Secretions of MGs as well as of SGs of nostrils, external auditory canals, and scalps were collected from healthy volunteers, analyzed by LCMS, and the data were processed using various multivariate statistical analysis approaches. Serial sections of MGs, free SGs, and hair-associated SGs were 3D reconstructed and compared. CK1 was expressed differently in hair-associated SGs than in MGs and other free SGs. The expression levels of CK8, CK10, and CK14 in MGs were different from those in hair-associated SGs and other free SGs. KRT15 was expressed differently in hair-associated SGs, whereas N-cadherin was expressed equally in all types of glands. The cell-cell contact markers Dsg1, Dp, Dsc3, Pg, and E-cadherin revealed no differences. ORO staining showed that lipids in MGs were more highly dispersed and had larger lipid droplets than lipids in other free SGs. Hair-associated SGs had a smaller number of lipid droplets. LCMS revealed that the lipid composition of meibum was distinctively different from that of the sebum of the nostrils, external auditory canals, and scalp. The 3D reconstructions of the different glands revealed different morphologies of the SGs compared with MGs which are by far the largest type of glands. In humans, MGs differ in their morphology and secretory composition and show major differences from free and hair-associated SGs. The composition of meibum differs significantly from that of sebum from free SGs and from hair-associated SGs. Therefore, the MG can be considered as a highly specialized type of holocrine gland that exhibits all the histological characteristics of SGs, but is significantly different from them in terms of morphology and lipid composition.

Oral Cannabidiol for Seborrheic Dermatitis in Patients With Parkinson Disease: Randomized Clinical Trial.

BACKGROUND: Seborrheic dermatitis (SD) affects 18.6%-59% of persons with Parkinson disease (PD), and recent studies provide evidence that oral cannabidiol (CBD) therapy could reduce sebum production in addition to improving motor and psychiatric symptoms in PD. Therefore, oral CBD could be useful for improving symptoms of both commonly co-occurring conditions. OBJECTIVE: This study investigates whether oral CBD therapy is associated with a decrease in SD severity in PD. METHODS: Facial photographs were collected as a component of a randomized (1:1 CBD vs placebo), parallel, double-blind, placebo-controlled trial assessing the efficacy of a short-term 2.5 mg per kg per day oral sesame solution CBD-rich cannabis extract (formulated to 100 mg/mL CBD and 3.3 mg/mL THC) for reducing motor symptoms in PD. Participants took 1.25 mg per kg per day each morning for 4 ±1 days and then twice daily for 10 ±4 days. Reviewers analyzed the photographs independently and provided a severity ranking based on the Seborrheic Dermatitis Area and Severity Index (SEDASI) scale. Baseline demographic and disease characteristics, as well as posttreatment SEDASI averages and the presence of SD, were analyzed with 2-tailed t tests and Pearson χ2 tests. SEDASI was analyzed with longitudinal regression, and SD was analyzed with generalized estimating equations. RESULTS: A total of 27 participants received a placebo and 26 received CBD for 16 days. SD severity was low in both groups at baseline, and there was no treatment effect. The risk ratio for patients receiving CBD, post versus pre, was 0.69 (95% CI 0.41-1.18; P=.15), compared to 1.20 (95% CI 0.88-1.65; P=.26) for the patients receiving the placebo. The within-group pre-post change was not statistically significant for either group, but they differed from each other (P=.07) because there was an estimated improvement for the CBD group and an estimated worsening for the placebo group. CONCLUSIONS: This study does not provide solid evidence that oral CBD therapy reduces the presence of SD among patients with PD. While this study was sufficiently powered to detect the primary outcome (efficacy of CBD on PD motor symptoms), it was underpowered for the secondary outcomes of detecting changes in the presence and severity of SD. Multiple mechanisms exist through which CBD can exert beneficial effects on SD pathogenesis. Larger studies, including participants with increased disease severity and longer treatment periods, may better elucidate treatment effects and are needed to determine CBD's true efficacy for affecting SD severity. TRIAL REGISTRATION: ClinicalTrials.gov NCT03582137; https://clinicaltrials.gov/ct2/show/NCT03582137.

What do we know about dermal bioaccessibility of metals coated on antibacterial films?

Antibacterial films have gained attention since the outbreak of the COVID-19 pandemic; however, the impact of metals contained in antibacterial films on human safety have not been sufficiently investigated. This study reports on the important features that must be considered when assessing the bioaccessibility of Ag, Cu, and Zn in antibacterial films. Specifically, the effects of the artificial sweat component (i.e., amino acid and pH), surface weathering of antibacterial films, wipe sampling, and sebum were carefully examined. Our findings suggest that amino acids greatly affect bioaccessibility as amino acids act as ligands to facilitate metal ion leaching. In addition, constant exposure to ultraviolet C causes the film surface to oxidize, which significantly increases metal bioaccessibility due to the electrostatic repulsion between metal oxides and organic substrates. The presence of sebum in artificial sweat and physical damage to the film surface had no significant effects. Furthermore, the wipe sampling used to mimic the realistic dermal contact suggests the feasibility of applying this method for the assessment of bioaccessibility of metals in antibacterial films. The method offers significant advantages for evaluating the human safety aspects of skin contact with consumer products in future research.

Sebum Components Dampen the Efficacy of Skin Disinfectants against Cutibacterium acnes Biofilms.

At Canadian Blood Services, despite the use of 2% chlorhexidine and 70% isopropyl alcohol (standard disinfectant, SD) prior to venipuncture, Cutibacterium acnes evades eradication and is a major contaminant of platelet concentrates (PCs). Since C. acnes forms bacterial aggregates known as biofilms in the sebaceous niches of the skin, this study aimed to assess whether sebum-like components impact disinfectant efficacy against C. acnes leading to its dominance as a PC contaminant. C. acnes mono-species and dual-species biofilms (C. acness and a transfusion-relevant Staphylococcus aureus isolate) were formed in the presence and absence of sebum-like components and exposed to SD, a hypochlorous acid-based disinfectant (Clinisept+, CP), or a combination of both disinfectants to assess disinfectant efficacy. Our data indicate that sebum-like components significantly reduce the disinfectant efficacy of all disinfectant strategies tested against C. acnes in both biofilm models. Furthermore, though none of the disinfectants led to bacterial eradication, the susceptibility of C. acnes to disinfectants was heightened in an isolate-dependent manner when grown in the presence of S. aureus. The reduction of skin disinfection efficacy in the presence of sebum may contribute to the overrepresentation of C. acnes as a PC contaminant and highlights the need for improved disinfection strategies.

Exploring the Multifaceted Impact of Acne on Quality of Life and Well-Being.

A suitable portion of the total population still suffers through acne vulgaris, a widespread dermatological illness that mostly affects teens and young adults. Although acne is typically considered to be a cosmetic problem, recent research has concluded that certainly it has a significant role on impacting many physiological aspects of human health. This thorough investigation attempts to examine the intricate effects of acne on human physiology, taking into consideration both systemic and local effects. The study synthesizes research from a number of scientific disciplines, including dermatology, endocrinology, immunology, and psychoneuroimmunology. It investigates the complex interrelationships between several factors, such as sebum production, follicular hyperkeratinization, hormone imbalance, and Propionibacterium acnes colonisation, that lead to the development of acne. The study also sheds information on the intricate physiological mechanisms, oxidative stress, and immune response that contribute to the aetiology of acne. Along with it, the review investigates the relationship between endocrine problems and acne, emphasizing hormonal anomalies and their possible role in acne severity. The psychological effects of acne are also discussed, including the psychological problems, concerns with self-esteem, and decreased quality of life that acne sufferers encounter. On comprehensively examining the diverse physiological aspects affected by acne, this review provides a foundation for future research endeavours and informs the development of targeted therapeutic interventions. Ultimately, the integration of multidisciplinary approaches will enable healthcare professionals to address the physiological complexities of acne and improve the overall well-being of individuals affected by this common skin condition.

A Murine Model for Measuring Sebum Production That Can Be Used to Test Therapeutic Agents for the Management of Acne Vulgaris.

Acne vulgaris (acne) effects nearly 90% of all Western teenagers, and the only pharmaceutical class of agents to treat severe forms of this skin condition are the retinoids, which are well-described teratogens. Yet about 50% of the patients receiving this class of therapeutics are women of child-bearing age, in their peak years of reproductive potential. On this basis, there is a significant unmet medical need for agents to treat severe forms of acne that do not carry this liability. As a means to assess potential agents of this type, here we describe methods for estimating the relative amount of sebum that a mouse produces based on the water retention on fur following a thorough wetting procedure. We have shown that a compound that is clinically effective in reducing sebum production demonstrates activity in this model. The method is therefore useful for evaluating therapeutic candidates for reducing sebum production, which would in turn be useful for treating acne. We have broken the entire procedure down into two phases/two protocols, as listed below. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Pre-wash wet weight measurement Basic Protocol 2: Post-wash wet-weight measurement.

The cutaneous effects of androgens and androgen-mediated sebum production and their pathophysiologic and therapeutic importance in acne vulgaris.

Background: The recognition of an association between the development of acne vulgaris (AV) and pubertal hormonal changes during adolescence dates back almost 100 years. Since these formative observations, a significant role of circulating hormones in the pathophysiology of AV and other cutaneous disorders has been established.Aims: This review article aims to provide an overview of clinical and preclinical evidence supporting the influences of androgens on the skin and their therapeutic importance in AV pathophysiology.Results: The cutaneous effects of hormones are attributable, to a large extent, to the influence of steroid hormones, particularly androgens, on sebocyte development and sebum production in both sexes. Androgen-mediated excess sebum production is implicated as a necessary early step in AV pathophysiology and is therefore considered an important therapeutic target in AV treatment. Although the local production and/or activity of androgens within the skin is believed to be important in AV pathophysiology, it has received limited therapeutic attention.Conclusions: We have summarized the current evidence in support of the therapeutic benefits of targeted hormonal treatment to decrease androgen-stimulated sebum production for the effective and safe treatment of AV in both male and female patients.

Investigating the impact of sebum secretion on liquid makeup foundation darkening and its solution.

OBJECTIVES: Darkening has been an issue of concern for foundation products. The secretion of sebum plays a significant role in the process of foundation darkening, but the underlying mechanisms and solutions have been rarely reported. The aim of this study was to explore the relationship between sebum secretion and liquid foundation darkening and to provide possible solutions for reducing sebum-induced darkening in liquid foundation. METHODS: Artificial sebum in different concentrations was added to a basic liquid foundation to simulate different stages of sebum secretion. The colour of the mixture was then measured by a spectrophotometer on the standard opacity chart. Potential technical solutions for anti-darkening were applied to a basic liquid foundation, and its ability to anti-darkening was further verified in vivo. RESULTS: (1) The influences of sebum addition on liquid foundation darkening had a significant positive correlation with the increase in transmissivities (R2 = 0.852, p < 0.01). (2) A certain range of sebum addition can reduce the darkening of volatile foundations. (3) The liquid foundations using pigments with high dispersibility in sebum were less influenced by sebum. (4) The replacement of pigments with oil-fixing ability could effectively reduce the darkening of liquid foundations induced by sebum (p < 0.01). CONCLUSION: The effect of sebum on the darkening of liquid foundation was accompanied by a greater transmissivity as its pigment concentration decreased. Balanced volatility, the addition of powders with higher sebum dispersibility and the replacement of oil-fixing powders could reduce the darkening of the liquid foundation caused by sebum secretion.

OBJECTIFS: L'assombrissement a été un problème de préoccupation pour les produits de fond de teint. La sécrétion de sébum joue un rôle significatif dans le processus d'assombrissement du fond de teint, mais les mécanismes sous-jacents et les solutions ont été rarement rapportés. L'objectif de cette étude était d'explorer la relation entre la sécrétion de sébum et l'assombrissement du fond de teint liquide, et de fournir des solutions possibles pour réduire l'assombrissement induit par le sébum dans le fond de teint liquide. MÉTHODES: Du sébum artificiel à différentes concentrations a été ajouté à un fond de teint liquide de base pour simuler différents stades de sécrétion de sébum. La couleur du mélange a ensuite été mesurée par un spectrophotomètre sur le tableau standard d'opacité. Des solutions techniques potentielles pour l'anti-assombrissement ont été appliquées à un fond de teint liquide de base et leur capacité à prévenir l'assombrissement a été vérifiée in vivo. RÉSULTATS: (1) Les influences de l'ajout de sébum sur l'assombrissement du fond de teint liquide avaient une corrélation significativement positive avec l'augmentation des transmissivités (R2 = 0.852 p < 0.01). (2) Une certaine plage de concentration de sebum peut réduire l'assombrissement des fondations volatiles. (3) Les fonds de teint liquides utilisant des pigments à haute dispersibilité dans le sébum étaient moins influencés par le sébum. (4) Le remplacement des pigments par des poudres à capacité de fixation d'huile pouvait efficacement réduire l'assombrissement des fonds de teint liquides induit par le sébum (p < 0.01). CONCLUSION: L'effet du sébum sur l'assombrissement du fond de teint liquide était accompagné d'une plus grande transmissivité à mesure que la concentration de son pigment diminuait. La volatilité équilibrée, l'ajout de poudres à plus grande dispersibilité de sébum et le remplacement de poudres à capacité de fixation d'huile pourraient réduire l'assombrissement du fond de teint liquide causé par la sécrétion de sébum.

Long-term efficacy and safety of nonablative monopolar radiofrequency in the treatment of moderate to severe acne vulgaris.

BACKGROUND: Acne vulgaris (AV) is a prevalent skin condition known for its potential to cause scarring and psychological distress, often leading to diminished self-esteem. While topical and oral treatments are commonly prescribed, some patients experience treatment failure, adverse effects, or contraindications to conventional therapies. In response to these challenges, laser and energy-based device therapies have emerged as promising alternatives for individuals who fall into these categories, showing considerable potential in the treatment of AV. OBJECTIVE: This study aimed to evaluate the long-term efficacy and safety of a nonablative monopolar radiofrequency (NMRF) in treatment of moderate to severe AV. METHODS: Twenty-four patients with moderate to severe AV underwent a series of two NMRF treatment sessions, spaced 4 weeks apart. To evaluate treatment outcomes, live in-person lesion counts and measurements of pore size and volume, and sebum production were quantified using Antera® 3D imaging system, and Sebumeter®, respectively. Patients' self-assessment data regarding degree of improvement and facial oiliness were gathered. Dermatology life quality index (DLQI) questionnaire was utilized to assess the impact of AV on their quality of life. All objective and subjective evaluations were conducted at the baseline, 1 month after the first treatment, and during follow-up visits 1, 3, and 6 months after the last treatment sessions. Adverse effects were also recorded during each visit. RESULTS: Twenty out of the 24 subjects completed the study protocol. The mean inflammatory lesion counts significantly reduced by 42.86% and 45.71% from the baseline at 3 (p = 0.027) and 6 months (p = 0.032) after the second treatment. Sebum excretion likewise significantly decreased from baseline by 11.62% (p = 0.012), 13.37% (p < 0.001), and 21.51% (p = 0.004), 1 month after the first treatment, 1 and 6 months after the second treatment, respectively. The pore volume continued to decrease by 35% (p = 0.003) and 41.5% (p < 0.001) at 1 and 6 months following the final treatment, respectively. The DLQI significantly decreased from 10.00 (interquartile range [IQR]: 6.50-15.00) to 2.00 (IQR: 1.00-4.75), corresponding to 80% improvement of the index, 1 month after the last treatment and was sustained up to the last follow-up visit. Patients' self-assessments on degree of improvement and facial oiliness also significantly improved following NMRF treatments. The treatments were well-tolerated without significant adverse effects. CONCLUSION: NMRF appears to be an effective and safe treatment for inflammatory AV, with therapeutic outcomes persisting up to 6 months after two treatment sessions.

The heterogeneity and complexity of skin surface lipids in human skin health and disease.

The outermost epidermal layer of the skin, the stratum corneum, is not simply a barrier that safeguards skin integrity from external insults and invaders, it is also a delicately integrated interface composed of firm, essentially dead corneocytes and a distinctive lipid matrix. Together, the stratum corneum lipid matrix and sebum lipids derived from sebaceous glands give rise to a remarkably complex but quite unique blend of skin surface lipids that demonstrates tremendous heterogeneity and provides the skin with its indispensable protective coating. The stratum corneum lipid matrix is composed primarily of three major lipid classes: ceramides, non-esterified fatty acids and cholesterol, whereas sebum is a waxy mixture predominantly composed of acylglycerols, wax esters, non-esterified fatty acids, squalene, cholesterol and cholesterol esters. The balance of these skin surface lipids in terms of their relative abundance, composition, molecular organisation and dynamics, and their intricate interactions play a crucial role in the maintenance of healthy skin. For that reason, even minuscule alterations in skin surface lipid properties or overall lipid profile have been implicated in the aetiology of many common skin diseases including atopic dermatitis, psoriasis, xerosis, ichthyosis and acne. Novel lipid-based interventions aimed at correcting the skin surface lipid abnormalities have the potential to repair skin barrier integrity and the symptoms associated with such skin diseases, even though the exact mechanisms of lipid restoration remain elusive.

A fast and non-invasive artificial intelligence olfactory-like system that aids diagnosis of Parkinson's disease.

BACKGROUND AND PURPOSE: Several previous studies have shown that skin sebum analysis can be used to diagnose Parkinson's disease (PD). The aim of this study was to develop a portable artificial intelligence olfactory-like (AIO) system based on gas chromatographic analysis of the volatile organic compounds (VOCs) in patient sebum and explore its application value in the diagnosis of PD. METHODS: The skin VOCs from 121 PD patients and 129 healthy controls were analyzed using the AIO system and three classic machine learning models were established, including the gradient boosting decision tree (GBDT), random forest and extreme gradient boosting, to assist the diagnosis of PD and predict its severity. RESULTS: A 20-s time series of AIO system data were collected from each participant. The VOC peaks at a large number of time points roughly concentrated around 5-12 s were significantly higher in PD subjects. The gradient boosting decision tree model showed the best ability to differentiate PD from healthy controls, yielding a sensitivity of 83.33% and a specificity of 84.00%. However, the system failed to predict PD progression scored by Hoehn-Yahr stage. CONCLUSIONS: This study provides a fast, low-cost and non-invasive method to distinguish PD patients from healthy controls. Furthermore, our study also indicates abnormal sebaceous gland secretion in PD patients, providing new evidence for exploring the pathogenesis of PD.

The primary role of sebum in the pathophysiology of acne vulgaris and its therapeutic relevance in acne management.

BACKGROUND: Sebum physiology and its contributions to acne vulgaris (AV) pathophysiology have been long debated. Within the pilosebaceous unit, androgens drive sebocyte production of sebum, comprising mono-, di-, and triglycerides (the latter converted to fatty acids); squalene; cholesterol; cholesterol esters; and wax esters. Upon release to the skin surface, human sebum has important roles in epidermal water retention, antimicrobial defenses, and innate immune responses. AIMS: Alterations in sebum alone and with other pathogenic factors (inflammation, follicular hyperkeratinization, and Cutibacterium acnes [C. acnes] proliferation) contribute to AV pathophysiology. Androgen-driven sebum production, mandatory for AV development, propagates C. acnes proliferation and upregulates inflammatory and comedogenic cascades. RESULTS: Some sebum lipids have comedogenic effects in isolation, and sebum content alterations (including elevations in specific fatty acids) contribute to AV pathogenesis. Regional differences in facial sebum production, coupled with patient characteristics (including sex and age), help exemplify this link between sebum alterations and AV lesion formation. CONCLUSIONS: To date, only combined oral contraceptives and oral spironolactone (both limited to female patients), oral isotretinoin and topical clascoterone (cortexolone 17α-propionate) modulate sebum production in patients with AV. A better understanding of mechanisms underlying sebaceous gland changes driving AV development is needed to expand the AV treatment armamentarium.

A Rare Presentation of Chronic Vulval Sinus: A Case Report.

We report an unusual case of the vulval sinus with persistent seroanguinous discharge in a 59-year-old postmenopausal woman. Examination revealed a 9-cm isolated sinus tract in the right labiocrural fold. This sinus tract was excised under anesthesia. Histological analysis showed skin with a deep dermal sinus tract showing edematous and heavily inflamed granulation tissue. There was no evidence of malignancy or dysplasia. Hidradenitis was ruled out on histology. This case report summarizes the importance of early diagnosis and prompt treatment involving complete excision of the vulval sinus to reduce long-term morbidity and consequences of this rare entity.

A review of sebum in mammals in relation to skin diseases, skin function, and the skin microbiome.

Diseases vary among and within species but the causes of this variation can be unclear. Immune responses are an important driver of disease variation, but mechanisms on how the body resists pathogen establishment before activation of immune responses are understudied. Skin surfaces of mammals are the first line of defense against abiotic stressors and pathogens, and skin attributes such as pH, microbiomes, and lipids influence disease outcomes. Sebaceous glands produce sebum composed of multiple types of lipids with species-specific compositions. Sebum affects skin barrier function by contributing to minimizing water loss, supporting thermoregulation, protecting against pathogens, and preventing UV-induced damage. Sebum also affects skin microbiome composition both via its antimicrobial properties, and by providing potential nutrient sources. Intra- and interspecific variation in sebum composition influences skin disease outcomes in humans and domestic mammal species but is not well-characterized in wildlife. We synthesized knowledge on sebum function in mammals in relation to skin diseases and the skin microbiome. We found that sebum composition was described for only 29 live, wild mammalian species. Sebum is important in dermatophilosis, various forms of dermatitis, demodicosis, and potentially white-nose syndrome. Sebum composition likely affects disease susceptibility, as lipid components can have antimicrobial functions against specific pathogens. It is unclear why sebum composition is species-specific, but both phylogeny and environmental effects may drive differences. Our review illustrates the role of mammal sebum function and influence on skin microbes in the context of skin diseases, providing a baseline for future studies to elucidate mechanisms of disease resistance beyond immune responses.

Thymic stromal lymphopoietin induces IL-4/IL-13 from T cells to promote sebum secretion and adipose loss.

BACKGROUND: The cytokine TSLP promotes type 2 immune responses and can induce adipose loss by stimulating lipid loss from the skin through sebum secretion by sebaceous glands, which enhances the skin barrier. However, the mechanism by which TSLP upregulates sebaceous gland function is unknown. OBJECTIVES: This study investigated the mechanism by which TSLP stimulates sebum secretion and adipose loss. METHODS: RNA-sequencing analysis was performed on sebaceous glands isolated by laser capture microdissection and single-cell RNA-sequencing analysis was performed on sorted skin T cells. Sebocyte function was analyzed by histological analysis and sebum secretion in vivo and by measuring lipogenesis and proliferation in vitro. RESULTS: This study found that TSLP sequentially stimulated the expression of lipogenesis genes followed by cell death genes in sebaceous glands to induce holocrine secretion of sebum. TSLP did not affect sebaceous gland activity directly. Rather, single-cell RNA-sequencing revealed that TSLP recruited distinct T-cell clusters that produce IL-4 and IL-13, which were necessary for TSLP-induced adipose loss and sebum secretion. Moreover, IL-13 was sufficient to cause sebum secretion and adipose loss in vivo and to induce lipogenesis and proliferation of a human sebocyte cell line in vitro. CONCLUSIONS: This study proposes that TSLP stimulates T cells to deliver IL-4 and IL-13 to sebaceous glands, which enhances sebaceous gland function, turnover, and subsequent adipose loss.

Volatile organic compounds analysis as promising biomarkers for Parkinson's disease diagnosis: A systematic review and meta-analysis.

OBJECTIVE: Researchers are investigating the potential of volatile organic compounds (VOCs) obtained from exhaled breath and sebum as non-invasive tools for early Parkinson's disease (PD) diagnosis. The present study aims to assess the feasibility of using VOC analysis for PD diagnosis and determine the overall diagnostic accuracy of the proposed tests. METHODS: We performed systematic searches based on the PRISMA guidelines to identify relevant studies on VOCs in PD diagnosis using exhaled breath or sebum samples. The selected articles were described, and meta-analysis was conducted on those that provided the sensitivity and specificity data. RESULTS: Out of 1268 articles initially identified, 8 met the inclusion criteria and provided specific sensitivity and specificity data for PD, which were included in the current meta-analysis. The pooled analysis of these findings showed a mean area under the receiver operating characteristic curve of 0.85, a sensitivity of 0.81 (95% confidence interval (CI): 0.72, 0.88), and a specificity of 0.76 (95% CI: 0.66, 0.84). CONCLUSION: The analysis of VOCs in exhaled breath and sebum has shown promise as a new avenue for non-invasive diagnosis of PD. VOCs' ability to distinguish PD from healthy controls suggests their potential clinical application in screening for the disease. Consequently, VOCs hold significant potential as biomarkers for PD diagnosis and offer a promising novel approach to identifying and diagnosing the condition.