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Molecules (Basel, Switzerland) Jun 2023Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance,... (Review)
Review
Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.
Topics: Humans; Skin Pigmentation; Melanins; Hyperpigmentation; Skin; Monophenol Monooxygenase
PubMed: 37375394
DOI: 10.3390/molecules28124839 -
Cells Aug 2022Skin aging is induced and sustained by chronological aging and photoaging. Aging skin pigmentation such as mottled pigmentation (senile lentigo) and melasma are typical... (Review)
Review
Skin aging is induced and sustained by chronological aging and photoaging. Aging skin pigmentation such as mottled pigmentation (senile lentigo) and melasma are typical signs of photoaging. The skin, like other human organs, undergoes cellular senescence, and senescent cells in the skin increase with age. The crosstalk between melanocytes as pigmentary cells and other adjacent types of aged skin cells such as senescent fibroblasts play a role in skin-aging pigmentation. In this review, we provide an overview of cellular senescence during the skin-aging process. The discussion also includes cellular senescence related to skin-aging pigmentation and the therapeutic potential of regulating the senescence process.
Topics: Aged; Aging; Cellular Senescence; Humans; Melanocytes; Skin Aging; Skin Pigmentation
PubMed: 36010618
DOI: 10.3390/cells11162541 -
International Journal of Molecular... Jun 2013UV radiation (UV) is classified as a "complete carcinogen" because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator... (Review)
Review
UV radiation (UV) is classified as a "complete carcinogen" because it is both a mutagen and a non-specific damaging agent and has properties of both a tumor initiator and a tumor promoter. In environmental abundance, UV is the most important modifiable risk factor for skin cancer and many other environmentally-influenced skin disorders. However, UV also benefits human health by mediating natural synthesis of vitamin D and endorphins in the skin, therefore UV has complex and mixed effects on human health. Nonetheless, excessive exposure to UV carries profound health risks, including atrophy, pigmentary changes, wrinkling and malignancy. UV is epidemiologically and molecularly linked to the three most common types of skin cancer, basal cell carcinoma, squamous cell carcinoma and malignant melanoma, which together affect more than a million Americans annually. Genetic factors also influence risk of UV-mediated skin disease. Polymorphisms of the melanocortin 1 receptor (MC1R) gene, in particular, correlate with fairness of skin, UV sensitivity, and enhanced cancer risk. We are interested in developing UV-protective approaches based on a detailed understanding of molecular events that occur after UV exposure, focusing particularly on epidermal melanization and the role of the MC1R in genome maintenance.
Topics: Animals; Humans; Melanins; Oxidative Stress; Skin; Skin Neoplasms; Skin Pigmentation; Ultraviolet Rays
PubMed: 23749111
DOI: 10.3390/ijms140612222 -
Indian Journal of Dermatology,... 2016Glutathione is a low molecular weight thiol-tripeptide that plays a prominent role in maintaining intracellular redox balance. In addition to its remarkable antioxidant... (Review)
Review
Glutathione is a low molecular weight thiol-tripeptide that plays a prominent role in maintaining intracellular redox balance. In addition to its remarkable antioxidant properties, the discovery of its antimelanogenic properties has led to its promotion as a skin-lightening agent. It is widely used for this indication in some ethnic populations. However, there is a dichotomy between evidence to support its efficacy and safety. The hype around its depigmentary properties may be a marketing gimmick of pharma-cosmeceutical companies. This review focuses on the various aspects of glutathione: its metabolism, mechanism of action and the scientific evidence to evaluate its efficacy as a systemic skin-lightening agent. Glutathione is present intracellularly in its reduced form and plays an important role in various physiological functions. Its skin-lightening effects result from direct as well as indirect inhibition of the tyrosinase enzyme and switching from eumelanin to phaeomelanin production. It is available in oral, parenteral and topical forms. Although the use of intravenous glutathione injections is popular, there is no evidence to prove its efficacy. In fact, the adverse effects caused by intravenous glutathione have led the Food and Drug Administration of Philippines to issue a public warning condemning its use for off-label indications such as skin lightening. Currently, there are three randomized controlled trials that support the skin-lightening effect and good safety profile of topical and oral glutathione. However, key questions such as the duration of treatment, longevity of skin-lightening effect and maintenance protocols remain unanswered. More randomized, double-blind, placebo-controlled trials with larger sample size, long-term follow-up and well-defined efficacy outcomes are warranted to establish the relevance of this molecule in disorders of hyperpigmentation and skin lightening.
Topics: Administration, Intravenous; Administration, Oral; Administration, Topical; Dietary Supplements; Glutathione; Humans; Hyperpigmentation; Oxidation-Reduction; Skin Lightening Preparations; Skin Pigmentation
PubMed: 27088927
DOI: 10.4103/0378-6323.179088 -
Anais Brasileiros de Dermatologia 2013Skin pigmentation is an important human phenotypic trait whose regulation, in spite of recent advances, has not yet been fully understood. The pigment melanin is... (Review)
Review
Skin pigmentation is an important human phenotypic trait whose regulation, in spite of recent advances, has not yet been fully understood. The pigment melanin is produced in melanosomes by melanocytes in a complex process called melanogenesis. The melanocyte interacts with endocrine, immune, inflammatory and central nervous systems, and its activity is also regulated by extrinsic factors such as ultraviolet radiation and drugs. We have carried out a review of the current understanding of intrinsic and extrinsic factors regulating skin pigmentation, the melanogenesis stages and related gene defects. We focused on melanocyte-keratinocyte interaction, activation of melanocortin type 1 receptor (MC1-R) by peptides (melanocyte-stimulating hormone and adrenocorticotropic hormone) resulting from proopiomelanocortin (POMC) cleavage, and mechanisms of ultraviolet-induced skin pigmentation. The identification and comprehension of the melanogenesis mechanism facilitate the understanding of the pathogenesis of pigmentation disorders and the development of potential therapeutic options.
Topics: Adrenocorticotropic Hormone; Humans; Keratinocytes; Melanins; Melanocyte-Stimulating Hormones; Melanocytes; Pigmentation Disorders; Receptor, Melanocortin, Type 1; Skin Pigmentation; Ultraviolet Rays
PubMed: 23539007
DOI: 10.1590/s0365-05962013000100009 -
Experimental Dermatology Apr 2021In the light of substantial discoveries in epithelial and hair pigmentation pathophysiology, this review summarizes the current understanding of skin pigmentation... (Review)
Review
In the light of substantial discoveries in epithelial and hair pigmentation pathophysiology, this review summarizes the current understanding of skin pigmentation mechanisms. Melanocytes are pigment-producing cells, and their key regulating transcription factor is the melanocyte-specific microphthalmia-associated transcription factor (m-MITF). Ultraviolet (UV) radiation is a unique modulator of skin pigmentation influencing tanning pathways. The delayed tanning pathway occurs as UVB produces keratinocyte DNA damage, causing p53-mediated expression of the pro-opiomelanocortin (POMC) gene that is processed to release α-melanocyte-stimulating hormone (α-MSH). α-MSH stimulates the melanocortin 1 receptor (MC1R) on melanocytes, leading to m-MITF expression and melanogenesis. POMC cleavage also releases β-endorphin, which creates a neuroendocrine pathway that promotes UV-seeking behaviours. Mutations along the tanning pathway can affect pigmentation and increase the risk of skin malignancies. MC1R variants have received considerable attention, yet the allele is highly polymorphic with varied phenotypes. Vitiligo presents with depigmented skin lesions due to autoimmune destruction of melanocytes. UVB phototherapy stimulates melanocyte stem cells in the hair bulge to undergo differentiation and upwards migration resulting in perifollicular repigmentation of vitiliginous lesions, which is under sophisticated signalling control. Melanocyte stem cells, normally quiescent, undergo cyclic activation/differentiation and downward migration with the hair cycle, providing pigment to hair follicles. Physiological hair greying results from progressive loss of melanocyte stem cells and can be accelerated by acute stress-induced, sympathetic driven hyperproliferation of the melanocyte stem cells. Ultimately, by reviewing the pathways governing epithelial and follicular pigmentation, numerous areas of future research and potential points of intervention are highlighted.
Topics: Hair Follicle; Humans; Melanocytes; Microphthalmia-Associated Transcription Factor; Skin Pigmentation; Stem Cells; Ultraviolet Rays; Ultraviolet Therapy; Vitiligo
PubMed: 33320376
DOI: 10.1111/exd.14260 -
Journal of the American Academy of... May 2021Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and... (Review)
Review
Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.
Topics: Acne Vulgaris; Humans; Light; Low-Level Light Therapy; Skin; Skin Pigmentation; Treatment Outcome
PubMed: 33640508
DOI: 10.1016/j.jaad.2021.02.048 -
Molecules (Basel, Switzerland) Mar 2020Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition... (Review)
Review
Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition to the stratospheric ozone layer filtering the most harmful UVC, human skin contains a photoprotective pigment called melanin to protect from UVB, UVA, and blue visible light. This pigment is a redox UV-absorbing agent and functions as a shield to prevent direct UV action on the DNA of epidermal cells. In addition, melanin indirectly scavenges reactive oxygenated species (ROS) formed during the UV-inducing oxidative stress on the skin. The amounts of melanin in the skin depend on the phototype. In most phenotypes, endogenous melanin is not enough for full protection, especially in the summertime. Thus, photoprotective molecules should be added to commercial sunscreens. These molecules should show UV-absorbing capacity to complement the intrinsic photoprotection of the cutaneous natural pigment. This review deals with (a) the use of exogenous melanin or melanin-related compounds to mimic endogenous melanin and (b) the use of a number of natural compounds from plants and marine organisms that can act as UV filters and ROS scavengers. These agents have antioxidant properties, but this feature usually is associated to skin-lightening action. In contrast, good photoprotectors would be able to enhance natural cutaneous pigmentation. This review examines flavonoids, one of the main groups of these agents, as well as new promising compounds with other chemical structures recently obtained from marine organisms.
Topics: Animals; Antioxidants; Aquatic Organisms; Flavonoids; Humans; Melanins; Oxidative Stress; Plants; Reactive Oxygen Species; Skin; Skin Pigmentation; Sunscreening Agents; Ultraviolet Rays
PubMed: 32230973
DOI: 10.3390/molecules25071537 -
International Journal of Cosmetic... Jun 2011Skin-lightening products are commercially available for cosmetic purposes to obtain lighter skin complexion. Clinically, they are also used for treatment of... (Review)
Review
Skin-lightening products are commercially available for cosmetic purposes to obtain lighter skin complexion. Clinically, they are also used for treatment of hyperpigmentary disorders such as melasma, café au lait spot and solar lentigo. All of these target naturally melanin production, and many of the commonly used agents are known as competitive inhibitors of tyrosinase, one of the key enzymes in melanogenesis. In this review, we present an overview of commonly used skin-whitening ingredients that are commercialized, but we also hypothesize on other mechanisms that could be important targets to control skin pigmentation such as for example regulation of the adrenergic and glutaminergic signalling and also control of tetrahydrobiopterins in the human skin.
Topics: Dermatologic Agents; Enzyme Inhibitors; Humans; Hyperpigmentation; Melanins; Melanosomes; Monophenol Monooxygenase; Skin Pigmentation
PubMed: 21265866
DOI: 10.1111/j.1468-2494.2010.00616.x -
Biomedicine & Pharmacotherapy =... Feb 2019Skin color disorders can be caused by various factors, such as excessive exposure to sunlight, aging and hormonal imbalance during pregnancy, or taking some medications.... (Review)
Review
Skin color disorders can be caused by various factors, such as excessive exposure to sunlight, aging and hormonal imbalance during pregnancy, or taking some medications. Kojic acid (KA) is a natural metabolite produced by fungi that has the ability to inhibit tyrosinase activity in synthesis of melanin. The major applications of KA and its derivatives in medicine are based on their biocompatibility, antimicrobial and antiviral, antitumor, antidiabetic, anticancer, anti-speck, anti-parasitic, and pesticidal and insecticidal properties. In addition, KA and its derivatives are used as anti-oxidant, anti-proliferative, anti-inflammatory, radio protective and skin-lightening agent in skin creams, lotions, soaps, and dental care products. KA has the ability to act as a UV protector, suppressor of hyperpigmentation in human and restrainer of melanin formation, due to its tyrosinase inhibitory activity. Also, KA could be developed as a chemo sensitizer to enhance efficacy of commercial antifungal drugs or fungicides. In general, KA and its derivatives have wide applications in cosmetics and pharmaceutical industries.
Topics: Animals; Antifungal Agents; Antioxidants; Cosmetics; Free Radical Scavengers; Humans; Hyperpigmentation; Melanins; Pyrones; Skin Pigmentation
PubMed: 30537675
DOI: 10.1016/j.biopha.2018.12.006