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Experimental Dermatology Sep 2015Increasing evidence has identified ultraviolet radiation (UVR) as the skins most potent mutagen as over exposure results in sunburn, inflammation and DNA damage, thus...
Increasing evidence has identified ultraviolet radiation (UVR) as the skins most potent mutagen as over exposure results in sunburn, inflammation and DNA damage, thus contributing to a photo-ageing phenotype and possibly skin carcinogenesis. The lipid-rich sebum secreted onto the surface of the skin plays an important physiological role in protecting the skin against external challenges. When skin is photosensitised by UVR, the lipid constituents of sebum are easily oxidised, generating several lipid photo-oxidative products (e.g. squalene peroxides). These photo-oxidative products have been shown to exert diverse toxicological, biological and immunological effects in the skin and have therefore been implicated in several detrimental skin alterations including premature skin ageing. The involvement of lipid peroxidation products in UVR-induced inflammatory responses has been inadequately studied and highly controversial. Furthermore, it is unclear to what extent these oxidative products contribute to the underlying mechanisms of skin photo-ageing. Therefore, this viewpoint essay will discuss the current knowledge on the effect of UVR exposure on skin surface lipids and how these may mediate UVR-induced inflammatory responses which may be key contributors to photo-damage in skin. This essay will also examine the potential role of inflammasomes (innate immune complexes) in the inflammatory response associated with UVR-induced lipid peroxidation. Limited evidence is available on the interactions between sebaceous lipids, downstream mediators and concomitant immune response in sun-exposed skin and clearer elucidation may lead to novel biomarkers of photo-ageing and the incorporation of new molecules into current skin therapies which better target oxidised lipids and or downstream mediators/pathways.
Topics: Humans; Immunomodulation; Inflammasomes; Inflammation; Lipid Metabolism; Lipid Peroxidation; Lipids; Oxidation-Reduction; Sebum; Skin Aging; Ultraviolet Rays
PubMed: 26014614
DOI: 10.1111/exd.12774 -
International Journal of Cosmetic... Feb 2023Botanical ingredients are widely used in hair- and skin-care products. However, few studies have investigated the effectiveness of botanical products on counteracting... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Botanical ingredients are widely used in hair- and skin-care products. However, few studies have investigated the effectiveness of botanical products on counteracting sebum synthesis and secretion.
OBJECTIVE
To investigate the composition of Lotus corniculatus seed extract (LC) and its potential inhibition of lipogenesis in SZ95 sebocytes and oily human skin.
METHODS
The active components of LC solutions were identified by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR). The in vitro effects of LC were evaluated using SZ95 cells treated with linoleic acid (LA) and dihydrotestosterone (DHT) and incubated with LCs for 24 h and 72 h. Lipogenesis was assessed by Oil Red O and Nile Red staining of the cells. In vivo effects were assessed on 30 subjects with oily skin who were enrolled in a randomized, blank-controlled trial and were treated with LC solution for 6 h and 4 weeks. The skin sebum contents and area on the forehead and cheeks were evaluated using a Sebumeter SM815 and Sebfix sebutape with Visioscan VC98. In addition, VISIA was used to collect half-face photos for analysis.
RESULTS
A novel active molecule, 5'-o-rhamnosyl uridine, was identified in LC. LC exhibited a dose-dependent inhibitory effect on LA and DHT-induced lipid synthesis. When 5% LC was applied for 3 h, the skin sebum contents and area were significantly reduced compared with the vehicle control, with an obvious reduction after 6 h. Continued use of the serum containing 5% LC for 4 weeks resulted in a significant reduction in the skin sebum contents and area. No adverse reactions were reported during the study.
CONCLUSIONS
Topical application of LC resulted in an immediate and long-lasting reduction of the sebum contents and area of oily human skin by reducing sebaceous lipogenesis through the LA and DHT pathways. This indicates the potential of LC as a new biological treatment for oily skin.
Topics: Humans; Sebum; Sebaceous Glands; Lipogenesis; Lotus; Oils; Plant Extracts
PubMed: 36324215
DOI: 10.1111/ics.12823 -
Skin Research and Technology : Official... Mar 2020Subjective facial skin type is most frequently determined by the amount of sebum, which showed trends across subjective skin types in most previous studies while not in... (Comparative Study)
Comparative Study
BACKGROUND
Subjective facial skin type is most frequently determined by the amount of sebum, which showed trends across subjective skin types in most previous studies while not in some. This study was conducted to evaluate the associations among subjective skin type, amount of sebum, stratum corneum hydration, and pore size in Thai women.
METHODS
Sixty-two healthy women with either self-described subjective oily or dry skin type were included and casual sebum level (CSL), sebum excretion rate (SER), clinical pore size score, mean pore area, and stratum corneum hydration were measured at several facial sites. Correlation coefficients between amount of sebum and other parameters were estimated.
RESULTS
Casual sebum level and sebum excretion rate were significantly higher in oily-skinned than dry-skinned group by 1.6-2.1 times. Mean pore area and clinical pore size score were not different between the 2 groups, nor did they correlate with CSL or SER. Corneometry was shown to be significantly higher in dry-skinned than oily-skinned group. Significant, negative correlations between corneometry and CSL were also found.
CONCLUSION
The subjective facial skin types were consistent with the amount of sebum, but not pore size or corneometry, among Thai women.
Topics: Adult; Body Water; Face; Female; Humans; Sebum; Skin; Skin Physiological Phenomena; Young Adult
PubMed: 31562649
DOI: 10.1111/srt.12792 -
Experimental Dermatology Jul 2023
Topics: Humans; Sebum; YAP-Signaling Proteins; Insulin-Like Growth Factor I; Sebaceous Glands; Acne Vulgaris; Lipogenesis
PubMed: 37017127
DOI: 10.1111/exd.14803 -
The British Journal of Dermatology May 1975The sebum excretion rate (SER) was measured in fifty-five patients with rosacea and 126 control subjects. The mean SER in the patients with rosacea was not increased,...
The sebum excretion rate (SER) was measured in fifty-five patients with rosacea and 126 control subjects. The mean SER in the patients with rosacea was not increased, nor was there any correlation between SER and severity of rosacea. Our data suggest that seborrhoea plays no part in the pathogenesis of rosacea.
Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Rosacea; Sebum; Secretory Rate; Skin
PubMed: 126074
DOI: 10.1111/j.1365-2133.1975.tb03122.x -
International Journal of Pharmaceutics Feb 2009To understand drug delivery to the sebum filled hair and sebaceous follicles, it is essential to use an artificial sebum as a surrogate of the human sebum for the... (Comparative Study)
Comparative Study
To understand drug delivery to the sebum filled hair and sebaceous follicles, it is essential to use an artificial sebum as a surrogate of the human sebum for the investigation of drug transport properties. Artificial sebum L was developed in-house based on the chemical similarity to human sebum. The partition and diffusion of model compounds (ethyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, and hexyl 4-hydroxybenzoate) were measured in human sebum, hamster ear and body sebum (a commonly used animal model), and four representative artificial sebum samples (N, S, F, and L) in which artificial sebums, N, S and F were selected based on the available literature. DSC and NMR studies were also conducted on all sebums to compare their melting properties and chemical compositions. In vitro studies show that the partition coefficients of the three model compounds in artificial sebum L were similar to that of human sebum, whereas the hamster ear and body sebum, and other three artificial sebum samples were different from that of human sebum. Additionally, the in vitro sebum flux (microg/(cm(2)min) of three model compounds through artificial sebum L was closer to that of human sebum when compared with the other three artificial sebum (N, S and F), hamster body and hamster ear sebum. The results of this study indicate that the artificial sebum L could be used as an alternative to human sebum, as the physicochemical properties of this artificial sebum is relatively similar to human sebum.
Topics: Administration, Cutaneous; Animals; Biological Transport; Calorimetry, Differential Scanning; Chromatography, High Pressure Liquid; Cricetinae; Drug Delivery Systems; Hair Follicle; Humans; Magnetic Resonance Spectroscopy; Models, Biological; Sebum; Species Specificity
PubMed: 18929636
DOI: 10.1016/j.ijpharm.2008.09.025 -
European Journal of Pharmacology Jun 2011The melanocortins (α-MSH, β-MSH, γ-MSH, and ACTH) bind to the melanocortin receptors and signal through increases in cyclic adenosine monophosphate to induce... (Review)
Review
The melanocortins (α-MSH, β-MSH, γ-MSH, and ACTH) bind to the melanocortin receptors and signal through increases in cyclic adenosine monophosphate to induce biological effects. The melanocortin MC(5) and MC(1) receptors are expressed in human sebaceous glands, which produce sebum, a lipid mixture of squalene, wax esters, triglycerides, cholesterol esters, and free fatty acids that is secreted onto the skin. Excessive sebum production is one of the major factors in the pathogenesis of acne. The expression of melanocortin MC(5) receptor has been associated with sebocyte differentiation and sebum production. Sebaceous lipids are down-regulated in melanocortin MC(5) receptor-deficient mice, consistent with the observation that α-MSH acts as a sebotropic hormone in rodents. These findings, which suggest that melanocortins stimulate sebaceous lipid production through the MC(5) receptor, led to our search for MC(5) receptor antagonists as potential sebum-suppressive agents. As predicted, an antagonist was shown to inhibit sebocyte differentiation in vitro, and to reduce sebum production in human skin transplanted onto immunodeficient mice. The melanocortin MC(5) receptor antagonists may prove to be clinically useful for the treatment of sebaceous disorders with excessive sebum production, such as acne.
Topics: Animals; Cell Differentiation; Humans; Lipids; Models, Theoretical; Receptors, Melanocortin; Sebaceous Glands; Sebum
PubMed: 21215742
DOI: 10.1016/j.ejphar.2010.10.100 -
The British Journal of Dermatology Nov 2005It is generally accepted that the severity of acne is correlated with facial sebum secretion. However, previous studies on the relation between seborrhoea and the...
BACKGROUND
It is generally accepted that the severity of acne is correlated with facial sebum secretion. However, previous studies on the relation between seborrhoea and the development of acne did not consider topographical differences in facial sebum secretion and used relatively vague acne severity grading systems.
OBJECTIVES
To elucidate the relation between topographical variations in facial sebum secretion and the severity of acne in women.
METHODS
Forty-six female controls and 46 women with acne were included in this study. The Sebumeter was used to measure facial sebum secretion in the following facial areas: forehead, nose, chin, and right and left cheek. We counted noninflammatory comedones and inflammatory acne lesions in the same areas. We compared sebum secretion between patients with acne and controls, and analysed the relation between the quantity of sebum secreted and the number of acne lesions.
RESULTS
Sebum secretions in the whole face and in the T- and U-zones (areas of high and low sebum secretion, respectively) were higher in patients with acne than in controls. There was no correlation between sebum quantity and acne lesion count in most facial regions.
CONCLUSIONS
Increased levels of facial sebum secretion were observed in patients with acne. Our findings indicate that increased sebum levels do not directly cause development of acne lesions.
Topics: Acne Vulgaris; Adult; Face; Female; Humans; Photography; Sebum; Severity of Illness Index; Skin
PubMed: 16225600
DOI: 10.1111/j.1365-2133.2005.06794.x -
Comparative Biochemistry and... 1983
Comparative Study Review
Topics: Aging; Androgens; Animals; Body Water; Ceramides; Chemical Phenomena; Chemistry; Epidermis; Fatty Acids; Humans; Lipids; Pituitary Hormones; Sebaceous Glands; Sebum; Skin Physiological Phenomena; Species Specificity; Structure-Activity Relationship
PubMed: 6362973
DOI: 10.1016/0305-0491(83)90376-0 -
International Journal of Cosmetic... Feb 2024Darkening 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...
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 (R = 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.
Topics: Sebum; Skin Physiological Phenomena; Spectrophotometry
PubMed: 38225855
DOI: 10.1111/ics.12939