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American Journal of Clinical Dermatology Mar 2022Photoprotection behaviors can mitigate skin damage caused by ultraviolet radiation, and common methods include seeking shade, avoiding sun exposure during peak daylight... (Review)
Review
Photoprotection behaviors can mitigate skin damage caused by ultraviolet radiation, and common methods include seeking shade, avoiding sun exposure during peak daylight hours, wearing sun-protective clothing, applying sunscreen, and using sunglasses. While the role of sun protection in preventing sunburns, photoaging, and skin cancer is well established in fair-skinned populations, individuals with skin of color (SOC) are presumed to suffer fewer negative effects from solar radiation. Thus, the importance of photoprotection in this population is understudied and may be underestimated. In SOC populations, sun exposure is known to cause pigmentary disorders, photoaging, and basal cell carcinoma (BCC), highlighting the potential benefits of photoprotection. Although SOC populations tend to practice photoprotection by seeking shade and wearing sun-protective clothing, survey and interview-based studies have consistently found relatively low use of sunscreen among these populations. Common motivators for photoprotection in individuals with SOC include preventing sunburn and pigmentation, with the prevention of skin cancer being a less important reason. As a skin cancer risk behavior, indoor tanning is relatively rare in SOC populations, but its use may increase with acculturation to US norms. While more studies are necessary to clarify whether photoprotection behaviors may decrease skin cancer-related mortality in SOC populations, regular dermatologic care and counseling on photoprotection remain essential in patients with SOC for overall skin health.
Topics: Humans; Skin; Skin Pigmentation; Sunburn; Sunscreening Agents; Ultraviolet Rays
PubMed: 35044638
DOI: 10.1007/s40257-021-00670-z -
Inflammation Research : Official... Aug 2022Excessive exposure of the skin to UV radiation (UVR) triggers a remodeling of the immune system and leads to the photoaging state which is reminiscent of chronological... (Review)
Review
BACKGROUND
Excessive exposure of the skin to UV radiation (UVR) triggers a remodeling of the immune system and leads to the photoaging state which is reminiscent of chronological aging. Over 30 years ago, it was observed that UVR induced an immunosuppressive state which inhibited skin contact hypersensitivity.
METHODS
Original and review articles encompassing inflammation and immunosuppression in the photoaging and chronological aging processes were examined from major databases including PubMed, Scopus, and Google Scholar.
RESULTS
Currently it is known that UVR treatment can trigger a cellular senescence and inflammatory state in the skin. Chronic low-grade inflammation stimulates a counteracting immunosuppression involving an expansion of immunosuppressive cells, e.g., regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and regulatory dendritic cells (DCreg). This increased immunosuppressive activity not only suppresses the function of effector immune cells, a state called immunosenescence, but it also induces bystander degeneration of neighboring cells. Interestingly, the chronological aging process also involves an accumulation of pro-inflammatory senescent cells and signs of chronic low-grade inflammation, called inflammaging. There is also clear evidence that inflammaging is associated with an increase in anti-inflammatory and immunosuppressive activities which promote immunosenescence.
CONCLUSION
It seems that photoaging and normal aging evoke similar processes driven by the remodeling of the immune system. However, it is likely that there are different molecular mechanisms inducing inflammation and immunosuppression in the accelerated photoaging and the chronological aging processes.
Topics: Aging; Humans; Immunosuppression Therapy; Inflammation; Skin; Skin Aging; Ultraviolet Rays
PubMed: 35748903
DOI: 10.1007/s00011-022-01598-8 -
Skin Pharmacology and Physiology 2018Ferulic acid has low toxicity and possesses many physiological functions (anti-inflammatory, antioxidant, antimicrobial activity, anticancer, and antidiabetic effect).... (Review)
Review
Ferulic acid has low toxicity and possesses many physiological functions (anti-inflammatory, antioxidant, antimicrobial activity, anticancer, and antidiabetic effect). It has been widely used in the pharmaceutical, food, and cosmetics industry. Ferulic acid is a free radical scavenger, but also an inhibitor of enzymes that catalyze free radical generation and an enhancer of scavenger enzyme activity. Ferulic acid has a protective role for the main skin structures: keratinocytes, fibroblasts, collagen, elastin. It inhibits melanogenesis, enhances angiogenesis, and accelerates wound healing. It is widely applied in skin care formulations as a photoprotective agent, delayer of skin photoaging processes, and brightening component. Nonetheless, its use is limited by its tendency to be rapidly oxidized.
Topics: Angiogenesis Inducing Agents; Animals; Antioxidants; Coumaric Acids; Humans; Regeneration; Ultraviolet Rays
PubMed: 30235459
DOI: 10.1159/000491755 -
Sports Health 2016Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high... (Review)
Review
CONTEXT
Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes.
EVIDENCE ACQUISITION
A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar.
STUDY DESIGN
Clinical review.
LEVEL OF EVIDENCE
Level 3.
RESULTS
AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks.
CONCLUSION
Individualized and appropriate acclimatization is an essential component of injury and illness prevention.
Topics: Acclimatization; Age Factors; Altitude; Altitude Sickness; Athletic Performance; Humans; Physical Conditioning, Human; Physical Education and Training; Sleep Wake Disorders; Ultraviolet Rays
PubMed: 26863894
DOI: 10.1177/1941738116630948 -
Journal of the European Academy of... Jul 2021Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin... (Review)
Review
Increasing evidence on the impact of the different wavelengths of sunlight on the skin demonstrates the need for tailored recommendations of sunscreen according to skin phototype and dermatoses, which is now possible due to advances in the filters and formulations of sunscreens. A selective literature search was performed by an international expert panel, focusing on the type of sunscreen to recommend for photoaging, skin cancers, photodermatoses, pigmentary disorders and skin inflammatory disorders. Protection against ultraviolet (UV)B is especially important for light skin as there is a high risk of sunburn, DNA damage and skin cancers. Darker skin may be naturally better protected against UVB but is more prone to hyperpigmentation induced by visible light (VL) and UVA. Protection against UVA, VL and infrared A can be helpful for all skin phototypes as they penetrate deeply and cause photoaging. Long-wave UVA1 plays a critical role in pigmentation, photoaging, skin cancer, DNA damage and photodermatoses. Adapting the formulation and texture of the sunscreen to the type of skin and dermatoses is also essential. Practical recommendations on the type of sunscreen to prescribe are provided to support the clinician in daily practice.
Topics: Humans; Skin Neoplasms; Sunburn; Sunlight; Sunscreening Agents; Ultraviolet Rays
PubMed: 33764577
DOI: 10.1111/jdv.17242 -
Journal of Cosmetic Dermatology Nov 2021Photoaging, ultra violet (UV) induced skin aging is a gradual process that depends on the time and intensity of solar radiation. (Review)
Review
BACKGROUND
Photoaging, ultra violet (UV) induced skin aging is a gradual process that depends on the time and intensity of solar radiation.
AIM
The aim of this paper was to review of the literature focused on in vitro studies explaining the mechanisms of photoaging.
METHODS
Electronic databases, including PubMed and MEDLINE, were searched for in vitro studies on the importance of UV radiation in the skin photoaging process of peer-reviewed scientific journals. Only articles available in English and full version publications were considered for this review.
RESULTS
Three main modes of UV radiation action on skin cells which lead to photoaging, there are changes in cell metabolism, induction of oxidative stress due to the change in enzyme activity.
CONCLUSION
The information gathered in this publication will help to better understand the complex and multidirectional mechanism of skin photoaging, which will contribute to the development of research on potential cosmetic products that provide effective and safe sun protection or repair damage caused by UV radiation.
Topics: Cosmetics; Oxidative Stress; Skin; Skin Aging; Ultraviolet Rays
PubMed: 33655657
DOI: 10.1111/jocd.14033 -
Photodermatology, Photoimmunology &... Nov 2022Melasma is a frequent photoexacerbated hyperpigmentary disorder, which can significantly impact on the quality of life. We sought to review the pathogenesis of melasma,... (Review)
Review
BACKGROUND/PURPOSE
Melasma is a frequent photoexacerbated hyperpigmentary disorder, which can significantly impact on the quality of life. We sought to review the pathogenesis of melasma, and the role of photoprotection in the prevention and treatment of this disorder.
METHODS
We conducted a narrative review of the literature. We performed literature searches with PubMed from January 1990 to December 2021 using the keywords "melasma," "pathogenesis," "ultraviolet radiation," "visible light," "photoprotection," and "sunscreens."
RESULTS
The physiopathology of melasma includes a complex interaction between genetics, sex hormones, and sun exposure. Visible light, in particular high-energy visible light (HEVL), and long-wave UVA (UVA1) play a key role in melasma pathophysiology, and recent research suggests that melasma shares many features with photoaging disorders. Melasma disproportionately affects dark-skinned individuals. Some 30% to 50% of South Americans and Asians, among other ethnicities, can present with melasma. Dark-skinned patients take fewer photoprotective measures. Also, the majority of melasma patients do not adequately follow photoprotection recommendations, including the application of sunscreen. Intensive use of a broad-spectrum sunscreen can prevent melasma in high-risk individuals, can lessen melasma severity (associated or not with depigmenting agents), and can reduce relapses.
CONCLUSIONS
Due to the physiopathology of melasma, sunscreens should be broad-spectrum with high sun protection factor, and provide high protection against UVA1 and VL. Sunscreens should be cosmetically acceptable and leave no white residue. Tinted sunscreens are an excellent choice, as pigments can protect from HEVL and UVA1, and may provide camouflage, but they must offer colors that match the skin tone of each patient.
Topics: Humans; Sunscreening Agents; Ultraviolet Rays; Quality of Life; Sun Protection Factor; Melanosis; Skin
PubMed: 35229368
DOI: 10.1111/phpp.12783 -
Cellular Senescence and the Senescence-Associated Secretory Phenotype as Drivers of Skin Photoaging.The Journal of Investigative Dermatology Apr 2021Chronic exposure to UVR is known to disrupt tissue homeostasis, accelerate the onset of age-related phenotypes, and increase the risk for skin cancer-a phenomenon... (Review)
Review
Chronic exposure to UVR is known to disrupt tissue homeostasis, accelerate the onset of age-related phenotypes, and increase the risk for skin cancer-a phenomenon defined as photoaging. In this paper, we review the current knowledge on how UV exposure causes cells to prematurely enter cellular senescence. We describe the mechanisms contributing to the accumulation of senescent cells in the skin and how the persistence of cellular senescence can promote impaired regenerative capacity, chronic inflammation, and tumorigenesis associated with photoaging. We conclude by highlighting the potential of senolytic drugs in delaying the onset and progression of age-associated phenotypes in the skin.
Topics: Cell Transformation, Neoplastic; Cellular Senescence; Humans; Skin; Skin Aging; Skin Neoplasms; Ultraviolet Rays
PubMed: 33349436
DOI: 10.1016/j.jid.2020.09.031 -
Nutrients Nov 2022Our skin is an organ with the largest contact area between the human body and the external environment. Skin aging is affected directly by both endogenous factors and... (Review)
Review
Our skin is an organ with the largest contact area between the human body and the external environment. Skin aging is affected directly by both endogenous factors and exogenous factors (e.g., UV exposure). Skin saccharification, a non-enzymatic reaction between proteins, e.g., dermal collagen and naturally occurring reducing sugars, is one of the basic root causes of endogenous skin aging. During the reaction, a series of complicated glycation products produced at different reaction stages and pathways are usually collectively referred to as advanced glycation end products (AGEs). AGEs cause cellular dysfunction through the modification of intracellular molecules and accumulate in tissues with aging. AGEs are also associated with a variety of age-related diseases, such as diabetes, cardiovascular disease, renal failure (uremia), and Alzheimer's disease. AGEs accumulate in the skin with age and are amplified through exogenous factors, e.g., ultraviolet radiation, resulting in wrinkles, loss of elasticity, dull yellowing, and other skin problems. This article focuses on the damage mechanism of glucose and its glycation products on the skin by summarizing the biochemical characteristics, compositions, as well as processes of the production and elimination of AGEs. One of the important parts of this article would be to summarize the current AGEs inhibitors to gain insight into the anti-glycation mechanism of the skin and the development of promising natural products with anti-glycation effects.
Topics: Humans; Glycation End Products, Advanced; Ultraviolet Rays; Skin; Skin Aging; Glycosylation; Renal Insufficiency
PubMed: 36364850
DOI: 10.3390/nu14214588 -
The Journal of Investigative Dermatology Jun 2022Nicotinamide (NAM), a NAM adenine dinucleotide precursor, is known for its benefits to skin health. Under standard culture conditions, NAM delays the differentiation and...
Nicotinamide (NAM), a NAM adenine dinucleotide precursor, is known for its benefits to skin health. Under standard culture conditions, NAM delays the differentiation and enhances the proliferation of human primary keratinocytes, leading to the maintenance of stem cells. In this study, we investigated the effects of NAM on photoaging in two-dimensional human primary keratinocyte cultures and three-dimensional organotypic epidermal models. In both models, we found that UVB irradiation and hydrogen peroxide induced human primary keratinocyte premature terminal differentiation and senescence. In three-dimensional organotypics, the phenotype was characterized by a thickening of the granular layer expressing filaggrin and loricrin, but thinning of the epidermis overall. NAM limited premature differentiation and ameliorated senescence, as evidenced by the maintenance of lamin B1 levels in both models, with decreased lipofuscin staining and reduced IL-6/IL-8 secretion in three-dimensional models, compared to those in UVB-only controls. In addition, DNA damage observed after irradiation was accompanied by a decline in energy metabolism, whereas both effects were partially prevented by NAM. Our data thus highlight the protective effects of NAM against photoaging and oxidative stress in the human epidermis and pinpoint DNA repair and energy metabolism as crucial underlying mechanisms.
Topics: Humans; Keratinocytes; Niacinamide; Oxidative Stress; Skin Aging; Ultraviolet Rays
PubMed: 34740582
DOI: 10.1016/j.jid.2021.10.021