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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 -
Journal of Natural Medicines Jan 2020Carotenoids are tetraterpene pigments that are distributed in photosynthetic bacteria, some species of archaea and fungi, algae, plants, and animals. About 850 naturally... (Review)
Review
Carotenoids are tetraterpene pigments that are distributed in photosynthetic bacteria, some species of archaea and fungi, algae, plants, and animals. About 850 naturally occurring carotenoids had been reported up until 2018. Photosynthetic bacteria, fungi, algae, and plants can synthesize carotenoids de novo. Carotenoids are essential pigments in photosynthetic organs along with chlorophylls. Carotenoids also act as photo-protectors, antioxidants, color attractants, and precursors of plant hormones in non-photosynthetic organs of plants. Animals cannot synthesize carotenoids de novo, and so those found in animals are either directly accumulated from food or partly modified through metabolic reactions. So, animal carotenoids show structural diversity. Carotenoids in animals play important roles such precursors of vitamin A, photo-protectors, antioxidants, enhancers of immunity, and contributors to reproduction. In the present review, I describe the structural diversity, function, biosyntheses, and metabolism of natural carotenoids.
Topics: Animals; Carotenoids; Fungi; Pigmentation; Plants
PubMed: 31588965
DOI: 10.1007/s11418-019-01364-x -
Head and Neck Pathology Mar 2019Black and brown pigmentation of the oral mucosa can occur due to a multitude of non-neoplastic causes. Endogenous or exogenous pigments may be responsible for oral... (Review)
Review
Black and brown pigmentation of the oral mucosa can occur due to a multitude of non-neoplastic causes. Endogenous or exogenous pigments may be responsible for oral discoloration which can range from innocuous to life-threatening in nature. Physiologic, reactive, and idiopathic melanin production seen in smoker's melanosis, drug-related discolorations, melanotic macule, melanoacanthoma and systemic diseases are presented. Exogenous sources of pigmentation such as amalgam tattoo and black hairy tongue are also discussed. Determining the significance of mucosal pigmented lesions may represent a diagnostic challenge for clinicians. Biopsy is indicated whenever the source of pigmentation cannot be definitively identified based on the clinical presentation.
Topics: Humans; Mouth Diseases; Mouth Mucosa; Pigmentation; Pigmentation Disorders
PubMed: 30671761
DOI: 10.1007/s12105-018-0980-9 -
Progress in Retinal and Eye Research Nov 2022Albinism is a pigment disorder affecting eye, skin and/or hair. Patients usually have decreased melanin in affected tissues and suffer from severe visual abnormalities,... (Review)
Review
Albinism is a pigment disorder affecting eye, skin and/or hair. Patients usually have decreased melanin in affected tissues and suffer from severe visual abnormalities, including foveal hypoplasia and chiasmal misrouting. Combining our data with those of the literature, we propose a single functional genetic retinal signalling pathway that includes all 22 currently known human albinism disease genes. We hypothesise that defects affecting the genesis or function of different intra-cellular organelles, including melanosomes, cause syndromic forms of albinism (Hermansky-Pudlak (HPS) and Chediak-Higashi syndrome (CHS)). We put forward that specific melanosome impairments cause different forms of oculocutaneous albinism (OCA1-8). Further, we incorporate GPR143 that has been implicated in ocular albinism (OA1), characterised by a phenotype limited to the eye. Finally, we include the SLC38A8-associated disorder FHONDA that causes an even more restricted "albinism-related" ocular phenotype with foveal hypoplasia and chiasmal misrouting but without pigmentation defects. We propose the following retinal pigmentation pathway, with increasingly specific genetic and cellular defects causing an increasingly specific ocular phenotype: (HPS1-11/CHS: syndromic forms of albinism)-(OCA1-8: OCA)-(GPR143: OA1)-(SLC38A8: FHONDA). Beyond disease genes involvement, we also evaluate a range of (candidate) regulatory and signalling mechanisms affecting the activity of the pathway in retinal development, retinal pigmentation and albinism. We further suggest that the proposed pigmentation pathway is also involved in other retinal disorders, such as age-related macular degeneration. The hypotheses put forward in this report provide a framework for further systematic studies in albinism and melanin pigmentation disorders.
Topics: Humans; Melanins; Mutation; Albinism; Retina; Pigmentation
PubMed: 35729001
DOI: 10.1016/j.preteyeres.2022.101091 -
Current Biology : CB Jan 2018Life in caves means life in perpetual darkness. This has two dramatic effects on animals: it eliminates the need to see and reduces the availability of food as there is...
Life in caves means life in perpetual darkness. This has two dramatic effects on animals: it eliminates the need to see and reduces the availability of food as there is no local photosynthesis. Food availability for cave dwellers is often seasonal, episodic or unscheduled. Like other cave animals, fish species adapted for cave life exhibit a suite of sensory, morphological, physiological and behavioral traits that are shared among species from phylogenetically distant families. Most cave fishes are entirely or partially blind. The most extreme of them, the obligatory cave-dwelling fish that spend their entire life in caves, are the subject of this primer. At present, over 200 such cavefish species have been described, and all of them have evolved independently from surface ancestors. Thus, each cavefish species is a replicate of the same natural experiment, testing the evolutionary response of a sighted surface fish to the absence of light and the limitations on food in a subterranean environment. The evolutionary responses converge on loss of eyes and pigmentation and the augmentation of other senses, such as taste, smell or mechanosensation, as well as a more efficient metabolism, changes in feeding behavior, altered activity levels, loss of circadian rhythmicity and increased wakefulness. However, not all of these troglomorphic traits are present in every cavefish species.
Topics: Adaptation, Biological; Animals; Biological Evolution; Caves; Eye; Fishes; Life History Traits; Ocular Physiological Phenomena; Phylogeny; Pigmentation
PubMed: 29374443
DOI: 10.1016/j.cub.2017.12.011 -
Indian Journal of Dermatology,... 2019The Q-switched Nd:YAG laser is an established modality of treatment for epidermal and dermal pigmented lesions. The dual wavelengths of 1064nm and 532nm are suited for... (Review)
Review
The Q-switched Nd:YAG laser is an established modality of treatment for epidermal and dermal pigmented lesions. The dual wavelengths of 1064nm and 532nm are suited for the darker skin tones encountered in India. Though this laser has become the one of choice for conditions such as nevus of Ota, Hori's nevus and tattoos, its role in the management of melasma and other acquired dermal melanoses is not clear. Despite several studies having been done on the Q-switched Nd:YAG laser in melasma, there is no consensus on the protocol or number of sessions required. Acquired dermal melanoses are heterogenous entities with the common features of pigment incontinence and dermal melanophages resulting in greyish macular hyperpigmentation. This article reviews the current literature on laser toning in melasma and the role of the Q-switched Nd:YAG laser in stubborn pigmentary disorders such as lichen planus pigmentosus. As the pathology is primarily dermal or mixed epidermal-dermal in these conditions, the longer wavelength of 1064nm is preferred due to its deeper penetration. Generally multiple sessions are needed for successful outcomes. Low fluence Q-switched Nd:YAG laser at 1064nm utilizing the multi-pass technique with a large spot size has been suggested as a modality to treat melasma. Varying degrees of success have been reported but recurrences are common on discontinuing laser therapy. Adverse effects such as mottled hypopigmentation have been reported following laser toning; these can be minimized by using larger spot sizes of 8 to 10mm with longer intervals (2 weeks) between sessions.
Topics: Female; Humans; Laser Therapy; Lasers; Lasers, Solid-State; Male; Melanosis; Skin Pigmentation
PubMed: 30027914
DOI: 10.4103/ijdvl.IJDVL_1086_16 -
International Journal of Biological... 2023Hair graying is a common and visible sign of aging resulting from decreased or absence of melanogenesis. Although it has been established that gray hair greatly impacts... (Review)
Review
Hair graying is a common and visible sign of aging resulting from decreased or absence of melanogenesis. Although it has been established that gray hair greatly impacts people's mental health and social life, there is no effective countermeasure other than hair dyes. It has long been thought that reversal of gray hair on a large scale is rare. However, a recent study reported that individual gray hair darkening is a common phenomenon, suggesting the possibility of large-scale reversal of gray hair. In this article, we summarize the regulation mechanism of melanogenesis and review existing cases of hair repigmentation caused by several factors, including monoclonal antibodies drugs, tyrosine kinase inhibitors (TKIs), immunomodulators, other drugs, micro-injury, and tumors, and speculate on the mechanisms behind them. This review offers some insights for further research into the modulation of melanogenesis and presents a novel perspective on the development of clinical therapies, with emphasis on topical treatments.
Topics: Humans; Hair; Hair Color; Hair Follicle; Melanocytes; Pigmentation; Administration, Topical; Mental Health
PubMed: 37781032
DOI: 10.7150/ijbs.86911 -
Trends in Ecology & Evolution Apr 2020Mammalian colors and color patterns are some of the most diverse and conspicuous traits found in nature and have been widely studied from genetic/developmental and... (Review)
Review
Mammalian colors and color patterns are some of the most diverse and conspicuous traits found in nature and have been widely studied from genetic/developmental and evolutionary perspectives. In this review we first discuss the proximate causes underlying variation in pigment type (i.e., color) and pigment distribution (i.e., color pattern) and highlight both processes as having a distinct developmental basis. Then, using multiple examples, we discuss ultimate factors that have driven the evolution of coloration differences in mammals, which include background matching, intra- and interspecific signaling, and physiological influences. Throughout, we outline bridges between developmental and functional investigatory approaches that help broaden knowledge of mammals' memorable external appearances, and we point out areas for future interdisciplinary research.
Topics: Animals; Biological Evolution; Color; Mammals; Phenotype; Pigmentation
PubMed: 31980234
DOI: 10.1016/j.tree.2019.12.008 -
Pigment Cell & Melanoma Research Jul 2021Skin complexion is among the most recognizable phenotypes between individuals and is mainly determined by the amount and type of melanin pigment deposited in the... (Review)
Review
Skin complexion is among the most recognizable phenotypes between individuals and is mainly determined by the amount and type of melanin pigment deposited in the epidermis. Persons with dark skin complexion have more of a brown/black pigment known as eumelanin in their epidermis whereas those with fair skin complexions have less. Epidermal eumelanin acts as a natural sunblock by preventing incoming UV photons from penetrating into the skin and therefore protects against UV mutagenesis. By understanding the signaling pathways and regulation of pigmentation, strategies can be developed to manipulate skin pigmentation to improve UV resistance and to diminish skin cancer risk.
Topics: Animals; Enzyme Inhibitors; Humans; Melanins; Pharmaceutical Preparations; Skin Pigmentation; Translational Research, Biomedical
PubMed: 33666358
DOI: 10.1111/pcmr.12969 -
ELife Jun 2021Hair greying is a hallmark of aging generally believed to be irreversible and linked to psychological stress.
BACKGROUND
Hair greying is a hallmark of aging generally believed to be irreversible and linked to psychological stress.
METHODS
Here, we develop an approach to profile hair pigmentation patterns (HPPs) along individual human hair shafts, producing quantifiable physical timescales of rapid greying transitions.
RESULTS
Using this method, we show white/grey hairs that naturally regain pigmentation across sex, ethnicities, ages, and body regions, thereby quantitatively defining the reversibility of greying in humans. Molecularly, grey hairs upregulate proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining HPP profiling and proteomics on single hairs, we also report hair greying and reversal that can occur in parallel with psychological stressors. To generalize these observations, we develop a computational simulation, which suggests a threshold-based mechanism for the temporary reversibility of greying.
CONCLUSIONS
Overall, this new method to quantitatively map recent life history in HPPs provides an opportunity to longitudinally examine the influence of recent life exposures on human biology.
FUNDING
This work was supported by the Wharton Fund and NIH grants GM119793, MH119336, and AG066828 (MP).
Topics: Adolescent; Adult; Aging; Child; Chromosome Mapping; Hair; Hair Color; Humans; Middle Aged; Stress, Psychological; Young Adult
PubMed: 34155974
DOI: 10.7554/eLife.67437