Sebum Excretion Rate Research Articles

An optimal method for quantifying the facial sebum level and characterizing facial sebum features.

Evidence suggests that sebum content is important in skin disorders such as acne. However, sebum levels change depending on the external environment, and quantifying skin sebum levels is challenging. Here, we propose an optimal method for quantifying the facial sebum level. Four hundred and sixty participants (160 males and 300 females) aged 20-40 were enrolled in this study. A Sebumeter SM 810 was used to measure the sebum level at five facial locations: the forehead, the chin, the left cheek, the right cheek, and the nose. The participants were divided into two groups; one group underwent a one-time measurement (n=390, male: female=120: 270), and the other underwent three consecutive measurements (n=70, male: female=40: 30). The casual sebum level (CSL) was measured in all patients after a 30-min acclimatization; subsequently, the sebum removal process was conducted, followed by a resting period of 1h to determine the sebum excretion rate (SER). Spearman's correlation analysis and the Wilcoxon signed-rank test were used to compare the sebum level consistency and differences between the groups. Although three consecutive measurements better reflected the sebum content, the one-time measurement also represented the relative sebum level. One hour after sebum removal, the sebum level recovered to 70%-90%; thus, this method was applicable for use in SER quantification. Of the five testing points, the sebum content was highest in the nose and lowest in the cheeks (both left and right). In addition, the cheeks were the most stable sites in terms of testing points, testing times, and CSL/SER values. A one-time measurement of the CSL could represent the SER 1h after the sebum removal. In our cohort, the sebum level of males with oily skin was decreased at age 32-35, and that of males with non-oily skin increased at 28-35. The opposite trend was observed in female participants. Sebum measurement methods were assessed, including testing times, indices (interval of time) and sites in a conditioned external environment. A one-time measurement of the CSL 1h after sebum removal was sufficient to determine the sebum level and SER, and the cheeks are recommended as the testing site. Sex and skin type differences were observed in sebum level changes with age.

Correlating the Gut Microbiota and Circulating Hormones with Acne Lesion Counts and Skin Biophysical Features.

Acne vulgaris is a common inflammatory condition that is multi-factorial and impacted by both intrinsic and extrinsic features. Several previous studies have assessed for correlations between factors such as circulating hormones, stress, or the microbiome. However, there have not been any correlations specifically against lesion counts or differentiating correlations between inflammatory and non-inflammatory lesion counts. Here, we correlate several factors against acne lesions. Twenty men and women with mild to moderate acne were recruited, and their hormonal levels and their gut microbiome were collected and correlated against their inflammatory and non-inflammatory lesions of acne. Facial non-inflammatory lesions were weakly correlated to sebum excretion rate and weakly inversely correlated to forehead and cheek hydration. We examined stress through the use of a normalized peak-to-trough ratio (higher numbers indicated less stress), which correlated with skin hydration and inversely correlated with sebum excretion rate. Sebum excretion rate was weakly correlated to testosterone levels, and facial hydration correlated with estradiol levels. Correlations with the gut microbiome showed differential correlations with inflammatory and non-inflammatory lesions, with Clostridium sp AF 23-8 correlating to inflammatory lesion counts, while Actinomyces naeslundii str Howell 279 correlated to non-inflammatory lesions. Overall, measures of stress and circulating hormones correlate to skin biophysical properties and acne lesion counts. Also, different gut bacteria correlate with either inflammatory or non-inflammatory lesion counts. We hope that our findings stimulate further work on the gut-mind-stress-skin axis within acne.

How do the skin barrier and microbiome adapt to the extra-uterine environment after birth? Implications for the clinical practice.

The multiple protective functions of the skin derive from the interactions between epithelial skin and immune cells as well as the commensal microbiota. Developed in the last trimester of intra-uterine life, the skin barrier adapts dynamically after birth. Specific differences in the structure and physiology have been disclosed between infant and adult skin. The stratum corneum of infants is thinner and structured by thicker corneocytes with a more anisotropic surface in comparison to adult skin. Lower levels of the natural moisturizing factor and its constituents, together with the increased protease activity in the epidermis result in dry baby skin and ongoing adaptation of the desquamation to the extra-uterine environment. Infant epidermis is characterized by an accelerated proliferation rate and clinically competent permeability barrier in term neonates, despite the higher baseline values of transepidermal water loss in infants. The skin surface of newborns is less acidic, which could increase susceptibility to diaper and atopic dermatitis. Immediately after birth, skin is colonized by commensal bacteria-a process dependent on the mode of delivery and of major importance for the maturation of the immune system. Skin bacterial diversity and dysbiosis have been related to different pathology such as atopic and seborrheic dermatitis. This paper focuses on the ongoing structural, functional and biochemical adaptation of the human skin barrier after birth. We discuss the interactions on the 'skin barrier/ microbiota/ immune system' axis and their role in the development of competent functional integrity of the epidermal barrier.

Randomized Double-Blind Placebo-Controlled Supplementation with Standardized Terminalia chebula Fruit Extracts Reduces Facial Sebum Excretion, Erythema, and Wrinkle Severity

Terminalia chebula (TC) is a medicinal plant that exhibits antioxidant, anti-inflammatory, and antibacterial properties and that is widely used in Ayurveda and herbal formulations. However, the skin effects of TC as an oral supplement have not been studied. The objective of this study is to determine if oral TC fruit extract supplementation can modulate the skin's sebum production and reduce the appearance of wrinkles. A prospective double-blind placebo-controlled study was conducted on healthy females aged 25-65. Subjects were supplemented with an oral placebo or Terminalia chebula (250 mg capsule, Synastol TC) capsules twice daily for eight weeks. A facial image collection and analysis system was used to assess the facial appearance of wrinkle severity. Standardized, non-invasive tools were used to measure facial moisture, sebum production, transepidermal water loss, melanin index and erythema index. For those who had a baseline sebum excretion rate >80 ug/cm2, TC supplementation produced a significant decrease in forehead sebum excretion rate compared to the placebo at four weeks (-17 decrease vs. 20% increase, p = 0.07) and at eight weeks (-33% decrease vs. 29% increase, p < 0.01). Cheek erythema decreased by 2.2% at eight weeks, while the placebo treatment increased cheek erythema by 1.5% (p < 0.05). Facial wrinkles decreased by 4.3% in the TC group and increased by 3.9% in the placebo group after eight weeks of supplementation (p < 0.05). TC supplementation reduces facial sebum and improves the appearance of wrinkles. Future studies should consider evaluating oral TC as adjuvant therapy for acne vulgaris.

Prospective Evaluation of a Topical Botanical Skin Care Regimen on Mild to Moderate Facial and Truncal Acne and Mood

Acne vulgaris is a common inflammatory condition that can be associated with profound psychosocial impacts. Conventional treatment includes topical retinoids, benzoyl peroxide, and antimicrobials, and some may cause irritation and skin dryness. In this 8-week open-label study, we examined the effects of a botanical skin care regimen (Codex Labs Shaant Balancing regimen) on mild to moderate facial and truncal acne. Twenty-four male and female subjects between the ages of 12 and 45 years were assessed for eligibility, 20 were enrolled, and 15 completed all study visits. Facial and truncal acne lesion counts, skin hydration, sebum excretion rate, and mood were assessed at baseline, week 4, and week 8. Total facial lesion counts (inflammatory and non-inflammatory lesions) decreased by 20.5% at week 4 (p = 0.06) and by 25.2% at week 8 (p < 0.05). Inflammatory lesion counts on the trunk were found to decrease at week 8 relative to baseline by 48% (p < 0.05). Forehead sebum excretion rate decreased by 40% at week 4 (p = 0.07) and 22% at week 8 (p = 0.08), and cheek skin hydration increased by 27.6% at week 4 (p = 0.14) and 65% at week 8 (p = 0.10). Participants also experienced significant improvement in components of a positive effect, such as feeling "strong" and "inspired", and a decrease in negative effects, such as feeling "irritable." Overall, the botanical skin care regimen was found to be well-tolerated. Our study suggests that a botanical skin care regimen may reduce facial and truncal acne lesion counts, increase skin hydration, reduce sebum production, and augment positive effects and moods in those with mild to moderate facial and truncal acne.

Prospective Placebo-Controlled Assessment of Spore-Based Probiotic Supplementation on Sebum Production, Skin Barrier Function, and Acne.

Probiotic supplementation has been shown to modulate the gut-skin axis. The goal of this study was to investigate whether oral spore-based probiotic ingestion modulates the gut microbiome, plasma short-chain fatty acids (SCFAs), and skin biophysical properties. This was a single-blinded, 8-week study (NCT03605108) in which 25 participants, 7 with noncystic acne, were assigned to take placebo capsules for the first 4 weeks, followed by 4 weeks of probiotic supplementation. Blood and stool collection, facial photography, sebum production, transepidermal water loss (TEWL), skin hydration measurements, and acne assessments were performed at baseline, 4, and 8 weeks. Probiotic supplementation resulted in a decreasing trend for the facial sebum excretion rate and increased TEWL overall. Subanalysis of the participants with acne showed improvement in total, noninflammatory, and inflammatory lesion counts, along with improvements in markers of gut permeability. The gut microbiome of the nonacne population had an increase in the relative abundance of Akkermansia, while the subpopulation of those with acne had an increase in the relative abundance of Lachnospiraceae and Ruminococcus gnavus. Probiotic supplementation augmented the circulating acetate/propionate ratio. There is preliminary evidence for the use of spore-based probiotic supplementation to shift the gut microbiome and augment short-chain fatty acids in those with and without acne. Further spore-based supplementation studies in those with noncystic acne are warranted.

Cold Atmospheric Plasma Inhibits Lipogenesis and Proliferation of Human Sebocytes and Decreases Sebum Production in Human Facial Skin

Background. Although several energy devices targeting sebaceous glands have been developed, an effective and safe therapeutic tool for hyperseborrhea is still needed. Nonthermal atmospheric‐pressure plasma (NTAPP) induces microscopic tissue reactions in sebaceous glands of rat skin. Objective. The aim of the study is to investigate the effects of NTAPP on sebum production in human skin in vivo followed by an experimental study of human sebocytes. Methods. Fourteen healthy volunteers with oily facial skin underwent three sessions of argon‐ and nitrogen‐NTAPP treatment at a 1‐week interval and were followed up for 8 weeks. The casual sebum level, sebum excretion rate, and porphyrin index were evaluated. Histological analysis was performed using skin biopsy specimens taken from two subjects at the baseline and week 2. SZ95 sebocytes were stimulated with testosterone and linoleic acid (T/LA) with or without treatment with NTAPP. BODIPY and Nile red staining were used for qualitative lipids analysis. Proliferation and differentiation markers were also assessed. Results. Casual sebum levels and sebum excretion rates in facial skin decreased by 26 and 24%, respectively, at week 4 compared to those of the baseline. Porphyrin index also decreased by 38% at week 2. Histologically, NTAPP‐treated human skin showed no obvious thermal injury, but the number of Ki67+ cells in the sebaceous glands decreased at week 2. Argon‐ and nitrogen‐NTAPP attenuated T/LA‐induced increases in neutral lipid accumulation, Ki67+ cells, and peroxisome proliferator‐activated receptor‐ɣ transcription in human sebocytes at energy settings that did not induce apoptosis. Conclusion. Argon‐ and nitrogen‐NTAPP can be a safe and effective therapeutic tool for hyperseborrhea‐associated diseases such as acne. This trial is registered with NCT04917835.

Prospective Randomized Double-Blind Placebo-Controlled Study of Oral Pomegranate Extract on Skin Wrinkles, Biophysical Features, and the Gut-Skin Axis.

(1) Background: The pomegranate fruit (Punica granatum L.) has been widely used in traditional medicine and has increasingly gained popularity among consumers in order to manage different facets of health. The objective of this study was to evaluate the effects of the fruit extract of P. granatum L. on different parameters of skin health. (2) Methods: A prospective, double-blind placebo-controlled study was conducted on both healthy males and females aged 25-55 years. Subjects were supplemented with a standardized punicalagin enriched oral pomegranate extract [Pomella® (Verdure Science, Noblesville, IN, USA), PE group] or a placebo (control group) daily for four weeks. Changes in wrinkle severity, facial biophysical properties, skin microbiome, and the gut microbiome were assessed. (3) Results: The PE group had significant reductions in wrinkle severity (p &lt; 0.01) and a decreasing trend in the forehead sebum excretion rate (p = 0.14). The participants in the PE group with a higher relative abundance of Eggerthellaceae in the gut had a decrease in their facial TEWL (p &lt; 0.05) and wrinkle severity (p = 0.058). PE supplementation led to an increase in the Staphylococcus epidermidis species and the Bacillus genus on the skin. (4) Conclusions: Overall, the study demonstrated improvements in several biophysical properties, wrinkles, and shifts in the skin microbiome with oral PE supplementation in healthy subjects.

Biophysical and Biological Tools to Better Characterize the Stability, Safety and Efficacy of a Cosmeceutical for Acne-Prone Skin.

(1) Background: Acne is a widespread skin disease, especially among adolescents. Following the COVID-19 pandemic and the use of masks, the problem has been affecting a greater number of people, and the attention of the skin care beauty routine cosmetics has been focused on the “Maskne”, caused by the sebum excretion rate (SER) that stimulates microbial proliferation. (2) Methods: the present study was focused on the rheological characterization and quality assurance of the preservative system of an anti-acne serum. The biological effectiveness (cytotoxicity—skin and eye irritation—antimicrobial, biofilm eradication and anti-inflammatory activity) was evaluated in a monolayer cell line of keratinocytes (HaCaT) and on 3D models (reconstructed human epidermis, RHE and human reconstructed corneal epithelium, HCE). The Cutibacterium acnes, as the most relevant acne-inducing bacterium, is chosen as a pro-inflammatory stimulus and to evaluate the antimicrobial activity of the serum. (3) Results and Conclusions: Rheology allows to simulate serum behavior at rest, extrusion and application, so the serum could be defined as having a solid-like behavior and being pseudoplastic. The preservative system is in compliance with the criteria of the reference standard. Biological effectiveness evaluation shows non-cytotoxic and irritant behavior with a good antimicrobial and anti-inflammatory activity of the formulation, supporting the effectiveness of the serum for acne-prone skin treatment.

Biostatistical Analysis on the Combination Treatment Against Acne

Introduction: Acne is one of the commonest skin disorders. During Adolescence 70% to 80% of the population have some clinically evident acne [1]. This is commonly seen as oily face, obstructive horny plugs or inflammatory lesions like pustules. These may complicate into cysts, abscesses, scars, keloids, hyper-pigmentation and above all psychological damage to self-confidence. The striking feature of acne is greasy skin and severity of acne is directly proportional to sebum excretion rate SER [2].

Randomized Controlled Pilot Study of Dietary Supplementation with Turmeric or Herbal Combination Tablets on Skin Barrier Function in Healthy Subjects.

To compare the effects of turmeric tablets and turmeric-containing herbal combination tablets versus placebo on skin barrier function and sebum production by measuring facial sebum and transepidermal water loss (TEWL) in healthy subjects. This study was a prospective, double-blinded, rater-blinded, randomized pilot study. Thirty-three generally healthy participants were recruited from the UC Davis Department of Dermatology clinic and the surrounding community from 2016 to 2017, 30 participants were enrolled, and 28 participants completed the study. Thirty individuals were recruited and randomized to the placebo, turmeric, or herbal combination tablet groups. The participants were instructed to take the intervention tablets by mouth twice daily for 4 weeks. Facial sebum production and TEWL were assessed at baseline and 4 weeks. Twenty-eight participants completed the study and there were no adverse events. There were no significant changes in sebum excretion rate in any group after 4 weeks compared with baseline. In the herbal combination tablet group, there was a significant decrease in TEWL (P = .003). No significant changes in TEWL were detected in the turmeric or placebo groups. Turmeric-containing herbal combination tablets significantly decreased TEWL after 4 weeks of twice-daily supplementation. There were no adverse events in any of the three intervention arms. Overall, our findings spark future interest in determining how oral supplementation with herbal formulations may improve skin barrier function and skin appearance, and potentially offer alternative or complementary treatment options.

CONTRACEPTION WITH FOLATES: NEW ASPECTS OF THE PROBLEM

Recently, the use of drospirenone-containing microdosed hormonal contraceptives containing folates has come at an opportune time. The common use of these contraceptives is associated with not only high efficacy and acceptability, but also with a positive effect on the symptoms of premenstrual syndrome, which is mediated by impact on the central nervous system. Drospirenonecontaining COCs are also known as products leading to a reduction in sebum excretion rates, which makes it possible to use them in acne therapy. Metafolin as part of microdosed hormonal contraceptive Yaz® plus compensates for the folate concentration required to prevent neural tube defects in the fetus in 27–30 days of pregnancy to some extent. Consequently, the use of drospirenone-containing hormonal contraceptives with folates provides not only a contraceptive, but also a therapeutic effect when fluid is retained in the body tissues. Thus, Yaz® plus product is indicated for use not only for contraceptive, but also for therapeutic purposes, as indicated in the patient information leaflet.

Evaluation of Sebostatic Activity of Juniperus communis Fruit Oil and Pelargonium graveolens Oil Compared to Niacinamide

As a facial skin condition, oily skin causes cosmetic problems, such as large pores, shiny appearance, and the feeling of greasiness and heaviness. Furthermore, extensive sebum production leads to common skin disorders such as acne vulgaris or seborrheic dermatitis. This study investigated the efficacy of sebum control tonics containing Juniperus communis fruit oil, Pelargonium graveolens oil, or niacinamide. The effects of Juniperus communis fruit oil, Pelargonium graveolens oil, and niacinamide on sebum excretion rates were investigated using Sebumeter®. Sebum measurements (Sebumeter® SM 815, Courage &amp; Khazaka®, Köln, Germany) were made on the skin surface in three places by applying the sebumeter probe to the forehead after 10, 60, and 120 min from application of the tonic. The results indicated that the application of the tonic maintained a lower sebum secretion 10 min and 60 min after the application of the cosmetic, compared to those before it. However, a visible sebum-reducing efficacy after 2 h was reported only for tonic containing 0.25% Pelargonium graveolens oil and for the tonic with the addition of 3% niacinamide. After 2 h, the values of sebum measurements were 44 ± 5.13 a.u. and 58 ± 9.07 a.u., respectively. Our results show that the tonic with the addition of 0.25% Pelargonium graveolens oil is the most effective in reducing sebum production.

A Topical Medication of All-Trans Retinoic Acid Reduces Sebum Excretion Rate in Patients With Forehead Acne.

Acne is a disease of the hair follicles of the face, chest, and back that affects almost all teenagers during puberty. This study is conducted to investigate if all-trans retinoic acid (ATRA) could reduce sebum excretion rate (SER) in acne patients by influencing content of skin-surface lipid production. Thirty-nine patients with forehead acne were topically treated with cream base (vehicle) and 0.025% ATRA cream once a night for 7 days. Separation and identification of sebum production collected from the skin on the acne were performed using thin-layer chromatography. SER was calculated according to the total amount of individual sebum productions that were quantified by using Alphaimager IS-2200 imaging analysis. Our data showed that the value of SER on the acne-affected skin was significantly decreased in the ATRA-treated patients as compared with ones treated with vehicle (P < 0.01). Treatment with ATRA resulted in inducing significant decreases in the contents of wax esters (WE), triglycerides and fatty acids, and free fatty acids (FFA) productions (all P < 0.01). In further analysis, the changes in the data before and after treatments with vehicle and ATRA were compared with significant differences exhibited in the values of SER, WE, and FFA (all P < 0.05). This study indicates that the topical application of ATRA in treatment of acne patients induces decrease in SER by inhibiting the excretion of WE and FFA productions.

Consequences of urban pollution upon skin status. A controlled study in Shanghai area.

After preliminary studies aimed at measuring pertinent biochemical parameters, potentially modified in subjects exposed to bad environmental conditions, a dedicated study was performed in Shanghai city to evaluate the effect of Urban pollution upon human skin and to collect feedback from the volunteers under study. This study was performed during summer 2008 in two different districts of Shanghai, on 159 local residents: 79 subjects from Xu Jia Hui (a centre Shanghainese area), more exposed to pollution, and 80 subjects from Chong Ming, an agricultural region closely located north of Shanghai (<100 kms) and less exposed to pollution, according to official data. Biochemical parameters were measured on skin, and feedback from volunteers was collected through a graduated 'Likert scale' questionnaire under a point scale (strongly agree, agree, disagree, strongly disagree and none). The study demonstrated significant differences in several biochemical parameters measured in Chong Ming area, as compared to Urban area, with an increased ratio of squalene/lipids, a lower level of lactic acid and a better cohesion of stratum corneum. Both sebum excretion rate and sebum casual levels did not differ between the two districts. The volunteer's feedback evidenced a perceived link between pollution and their skin problems. This study demonstrated a significant impact of the pollution upon the skin status, as illustrated by changes in superficial biochemical parameters and volunteers' perception.

Evaluation of the impact of urban pollution on the quality of skin: a multicentre study in Mexico.

After pilot and preliminary studies aimed at identifying pertinent biochemical parameters, a multicenter clinical study was performed to evaluate the effect of pollution on human skin. The clinical study was performed in collaboration with the 'Centre Régional de lutte contre le cancer de Montpellier' and the 'National Institute of Public Health of Mexico' on 96 subjects in Mexico City (exposed to pollution) and 93 subjects in Cuernavaca (less exposed to pollution). Both biochemical and clinical skin parameters were studied. The study demonstrated significant quantitative and qualitative modifications of parameters related to sebum excretion in Mexico City compared to Cuernavaca one: An increased level of sebum excretion rate, a lower level of vitamin E and squalene in sebum, an increase of lactic acid and a higher erythematous index on the face of the subjects. In the stratum corneum, a significant higher level of carbonylated proteins and a lower level of IL 1α were noticed, as well as a decrease of ATP concentration with a decrease of chymotrysin like activity, without modifications of corneodesmosin content and trypsin like activity. From a clinical point of view, a higher frequency of atopic and urticarial skins, a higher frequency of red dermographism, an important seborrheic status at the forehead level and a lower level of dandruffs were noted in Mexico City population. The analysis taking into account the sex does not modify the observed results. The study demonstrated an important impact of polluted environmental conditions on skin quality, evidencing important modifications of superficial biochemical parameters. The cause/effects relationships of these modifications remain, however, to be further assessed by a complementary in vitro/in vivo approaches.

The association of the sebum excretion rate with melasma, erythematotelangiectatic rosacea, and rhytides

Rosacea and melasma are two common skin conditions in dermatology. Both conditions have a predilection for the centrofacial region where the sebaceous gland density is the highest. However it is not known if sebaceous function has an association with these conditions. We aimed to assess the relationship between facial glabellar wrinkle severity and facial sebum excretion rate for individuals with rosacea, melasma, both conditions, and in those with rhytides. Secondly, the purpose of this study was to utilize high resolution 3D facial modeling and measurement technology to obtain information regarding glabellar rhytid count and severity. A total of 21 subjects participated in the study. Subjects were divided into four groups based on facial features: rosacea-only, melasma-only, rosacea and melasma, rhytides-only. A high resolution facial photograph was taken followed by measurement of facial sebum excretion rate (SER). The SER was found to decline with age and with the presence of melasma. The SER negatively correlated with increasing Wrinkle Severity Rating Scale. Through the use of 3D facial modeling and skin analysis technology, we found a positive correlation between clinically based grading scores and computer generated glabellar rhytid count and severity. Continuing research with facial modeling and measurement systems will allow for development of more objective facial assessments. Future studies need to assess the role of technology in stratifying the severity and subtypes of rosacea and melasma. Furthermore, the role of sebaceous regulation may have important implications in photoaging.

Changes in serum free testosterone, sleep patterns, and 5-alpha-reductase type I activity influence changes in sebum excretion in female subjects.

Sebum is thought to play an important role in acne vulgaris and sebum excretion rate (SER) is often used as a marker of efficacy in acne studies. This study explored factors that could induce intra-subject variability in SER. SER was measured twice, 7 days apart, on the forehead of 40 healthy subjects. At each visit, the following parameters were also evaluated: serum androgen levels, 5-alpha-reductase type I gene expression, forehead temperature, sleep habits, diet, facial washing routine, and UV exposure. There was a positive correlation between the time subjects fell asleep on Day 0 and the change in SER for the left (P=0.010; R=0.402) and right sides (P=0.002; R=0.467) of the forehead. There was a significant inverse correlation between SER and 5-alpha-reductase type 1 expression and between free testosterone levels and 5-alpha-reductase type 1 expression. In sub-analyses performed on men and women, these correlations were only significant for women. Variations in sleep patterns, free testosterone, and 5-alpha-reductase type 1 activity are associated with changes in sebum excretion in women. This could explain some of the inter-subject variability in SER measured between visits in clinical studies.

Modulation of sebum oxidation and interleukin‐1α levels associates with clinical improvement of mild comedonal acne

Sebum plays a key role in the initiation of the acne lesions. Oxidized sebum lipids cause keratynocytes hyperproliferation and inflammatory cytokines release. Association between sebum oxidation and comedogenesis has been little investigated in comedonal acne. Evaluation of sebum oxidation parameters and levels of inflammatory cytokines (IL-1α) in patients with mild comedonal acne (MCA) before and after the treatment with a mixed RetinSphere® - vitamin E formulation. Sebum excretion rate (SER), squalene concentration, and oxidation degree of sebum were measured in 18 MCA patients and 10 controls. IL-1α levels in the stratum corneum were measured in both lesional and non-lesional facial areas of MCA patients. Sebum parameters and IL-1α were measured at week 4 of topical treatment. Reflectance confocal microscopy (RCM) was performed in a subset of four patients at the baseline and at week 4 and all patients were assessed clinically before and following the 8 week-treatment. Sebum excretion rate and squalene concentration were comparable between MCA patients and healthy controls. Lipid peroxidation (LPO) and the percentage of oxidized squalene (SQOX) were significantly elevated in the sebum of MCA patients. The concentration of the proinflammatory cytokine IL-1α in stratum corneum was significantly higher in the lesional area compared with non-lesional area of the MCA patients at the baseline. At week 4, while SER and squalene concentration did not vary significantly, the LPO levels and the SQOX percentage resulted decreased at a significant extent. Following the treatment, IL-1α concentration in the lesional area reached values comparable to those of unaffected areas. Consistent with the biochemical data, RCM showed the reduction of hyperkeratinization and of inflammatory cells infiltration of the adnexal structures epithelium, significant clinical improvement was recorded at week 8. The data further support the involvement of lipid oxidation and particularly by-products of squalene oxidation in comedogenesis.

아시아인의 얼굴색 변화와 인지도간 상관성 비교 : 한국인, 인도네시아인, 베트남인

수분량, 유분량, 피부밝기, pH 등 피부 특성을 나타내는 지표들은 환경적, 유전적 요소에 따라 다르게 나타난다. 하지만 이는 절대적인 피부 특성을 나타내는 것으로 사람들이 느끼는 감성적인 피부 특성과는 차이가 있다. 이를 반영하듯 최근 임상 연구들은 절대적인 피부 변화를 통한 사람들의 인지 변화에 관한 연구들이 주를 이루고 있다. 본 연구에서는 아시아인을 대상으로 국가별로 절대적인 피부색의 차이 뿐 아니라 실제 피부색의 변화에 따라 본인들이 인지하는 피부 밝기에도 차이가 있는지를 규명하고자 하였다. 아시아 3개국 총 410명의 피험자들이 본 연구에 참여하였으며 설문을 통해 본인들이 생각하는 피부밝기를 3단계로 구분하여 응답하고 본인이 생각하는 피부 밝기 변화에 따라 실제 피부색은 어떤 양상으로 변화하는지를 분석하였다. 국적에 관계 없이 모든 참가자들이 공통적으로 피부색이 밝다고 느낄수록 실제 피부 밝기는 증가하는 양상을 보였지만 절대적인 피부색과 피부가 밝다고 느끼는 정도는 차이가 있었다. 게다가, 피부 붉은기와 노란기의 변화도 국가별로 다른 양상을 보였다. 결론적으로, 본 연구 결과에 근거하여 판단 할 때 본인들의 피부 밝기를 인지하는 요소는 절대적인 피부 밝기가 아닌 국가별로 다른 기준이 적용된다는 것을 확인할 수 있었다. Various indicators representing skin characteristics such as skin hydration, sebum excretion rate, lightness, and pH are different depending on environmental and genetic factors. However, they are absolute skin indicators and are different from skin characteristics that a person recognizes. Based on this fact, many recent studies have been mainly conducting researches on perspective changes according to changes of absolute skin. This study was proposed not only to find out differences on skin colors of asian by nations, but also to find out whether there was any difference in skin brightness they perceive depending on actual skin color changing. As many as 410 subjects of three Asia nations were participated in this study, and investigated their responses on skin brightness using questionnaire, which was answered their skin color in three different levels. It was also were analyzed how actual skin brightness were changed depending on their perceived skin color changes of subjects. There was a trend showing that the brightness of the actual skin color was increased when participants felt their skin color got brighter regardless of their nationalities. However, there were some differences in color between perceived color and actual color. In addition, there was a different aspect by nations in changes of skin redness and skin yellowness. In conclusion, it was revealed that factors which help people to perceive their own skin brightness were not based on absolute skin brightness, but on different criteria depending on where they are from.