-
Journal of Fungi (Basel, Switzerland) Aug 2023Synthetic dyes are generally not safe for human health or the environment, leading to the continuous search and growing demand for natural pigments that are considered... (Review)
Review
Synthetic dyes are generally not safe for human health or the environment, leading to the continuous search and growing demand for natural pigments that are considered safer, biodegrade more easily, and are environmentally beneficial. Among micro-organisms, fungi represent an emerging source of pigments due to their many benefits; therefore, they are readily viable on an industrial scale. Among all the bioactive pigments produced by fungi, melanin is an enigmatic, multifunctional pigment that has been studied for more than 150 years. This dark pigment, which is produced via the oxidative polymerization of phenolic compounds, has been investigated for its potential to protect life from all kingdoms, including fungi, from biotic and abiotic stresses. Over time, the research on fungal melanin has attracted a significant amount of scientific interest due to melanin's distinct biological activities and multifarious functionality, which is well-documented in the literature and could possibly be utilized. This review surveys the literature and summarizes the current discourse, presenting an up-to-date account of the research performed on fungal melanin that encompasses its types, the factors influencing its bioactivity, the optimization of fermentation conditions to enhance its sustainable production, its biosynthetic pathways, and its extraction, as well as biochemical characterization techniques and the potential uses of melanin in a wide range of applications in various industries. A massive scope of work remains to circumvent the obstacles to obtaining melanin from fungi and exploring its future prospects in a diverse range of applications.
PubMed: 37754999
DOI: 10.3390/jof9090891 -
Clinical, Cosmetic and Investigational... 2023The long-pulse alexandrite laser uses Cr:BeAlO crystals as the activation medium and has a 755nm wavelength and millisecond pulse duration. The long-pulse alexandrite... (Review)
Review
The long-pulse alexandrite laser uses Cr:BeAlO crystals as the activation medium and has a 755nm wavelength and millisecond pulse duration. The long-pulse alexandrite laser has been utilized for hair removal, vascular lesions, pigmented lesions, and other conditions because melanin and hemoglobin in the skin, subcutaneous tissues, and skin appendages can specifically absorb this type of laser. To serve as a guide and source of inspiration for the clinical use of this type of laser, we review the present research status and advancement of the long-pulse alexandrite laser in the treatment of the aforementioned categories of disorders.
PubMed: 38021435
DOI: 10.2147/CCID.S441169 -
Cancers Nov 2023A common feature of Parkinson's disease (PD) and melanoma is their starting points being based on cells capable of converting tyrosine into melanin. Melanocytes produce... (Review)
Review
A common feature of Parkinson's disease (PD) and melanoma is their starting points being based on cells capable of converting tyrosine into melanin. Melanocytes produce two types of melanin: eumelanin and pheomelanin. These dyes are designed to protect epidermal cells from the harmful effects of UV radiation. Neurones of the substantia nigra, which degenerate during PD, produce neuromelanin, the physiological role of which is not fully explained. This article discusses the potential role of melanins in the pathogenesis of both diseases. Melanins, due to their ability to accumulate toxic substances, may become their sources over time. The use of glutathione for the synthesis of pheomelanins and neuromelanins may reduce the antioxidant capacity of cells, leading to an excessive synthesis of free radicals. This study also tested the hypothesis that certain drugs used in the treatment of PD (L-DOPA, MAO-B and COMT inhibitors, and amantadine), aimed at increasing dopamine concentration, could potentially contribute to the development of melanoma. The role and properties of melanins should continue to be researched. Whether excessive melanin synthesis or its accumulation in the extracellular space may be factors initiating the development of diseases remains an open question.
PubMed: 38067245
DOI: 10.3390/cancers15235541 -
Proceedings of the National Academy of... Oct 2023Most biocatalytic processes in eukaryotic cells are regulated by subcellular microenvironments such as membrane-bound or membraneless organelles. These natural...
Most biocatalytic processes in eukaryotic cells are regulated by subcellular microenvironments such as membrane-bound or membraneless organelles. These natural compartmentalization systems have inspired the design of synthetic compartments composed of a variety of building blocks. Recently, the emerging field of liquid-liquid phase separation has facilitated the design of biomolecular condensates composed of proteins and nucleic acids, with controllable properties including polarity, diffusivity, surface tension, and encapsulation efficiency. However, utilizing phase-separated condensates as optical sensors has not yet been attempted. Here, we were inspired by the biosynthesis of melanin pigments, a key biocatalytic process that is regulated by compartmentalization in organelles, to design minimalistic biomolecular condensates with emergent optical properties. Melanins are ubiquitous pigment materials with a range of functionalities including photoprotection, coloration, and free radical scavenging activity. Their biosynthesis in the confined melanosomes involves oxidation-polymerization of tyrosine (Tyr), catalyzed by the enzyme tyrosinase. We have now developed condensates that are formed by an interaction between a Tyr-containing peptide and RNA and can serve as both microreactors and substrates for tyrosinase. Importantly, partitioning of Tyr into the condensates and subsequent oxidation-polymerization gives rise to unique optical properties including far-red fluorescence. We now demonstrate that individual condensates can serve as sensors to detect tyrosinase activity, with a limit of detection similar to that of synthetic fluorescent probes. This approach opens opportunities to utilize designer biomolecular condensates as diagnostic tools for various disorders involving abnormal enzymatic activity.
Topics: RNA; Melanins; Monophenol Monooxygenase; Proteins; Peptides; Organelles
PubMed: 37871222
DOI: 10.1073/pnas.2310569120 -
Investigative Ophthalmology & Visual... Nov 2023The purpose of this study was to demonstrate the utility of polarization-diversity optical coherence tomography (PD-OCT), a noninvasive imaging technique with...
PURPOSE
The purpose of this study was to demonstrate the utility of polarization-diversity optical coherence tomography (PD-OCT), a noninvasive imaging technique with melanin-specific contrast, in the quantitative and qualitative assessment of choroidal nevi.
METHODS
Nevi were imaged with a custom-built 55-degree field-of-view (FOV) 400 kHz PD-OCT system. Imaging features on PD-OCT were compared to those on fundus photography, auto-fluorescence, ultrasound, and non-PD-OCT images. Lesions were manually segmented for size measurement and metrics for objective assessment of melanin distributions were calculated, including degree of polarization uniformity (DOPU), attenuation coefficient, and melanin occupancy rate (MOR).
RESULTS
We imaged 17 patients (mean age = 69.5 years, range = 37-90) with 11 pigmented, 3 non-pigmented, and 3 mixed pigmentation nevi. Nevi with full margin acquisition had an average longest basal diameter of 5.1 mm (range = 2.99-8.72 mm) and average height of 0.72 mm (range = 0.37 mm-2.09 mm). PD-OCT provided clear contrast of choroidal melanin content, distribution, and delineation of nevus margins for melanotic nevi. Pigmented nevi were found to have lower DOPU, higher attenuation coefficient, and higher MOR than non-pigmented lesions. Melanin content on PD-OCT was consistent with pigmentation on fundus in 15 of 17 nevi (88%).
CONCLUSIONS
PD-OCT allows objective assessment of choroidal nevi melanin content and distribution. In addition, melanin-specific contrast by PD-OCT enables clear nevus margin delineation and may improve serial growth surveillance. Further investigation is needed to determine the clinical significance and prognostic value of melanin characterization by PD-OCT in the evaluation of choroidal nevi.
Topics: Humans; Adult; Middle Aged; Aged; Aged, 80 and over; Tomography, Optical Coherence; Melanins; Nevus, Pigmented; Nevus; Choroid Neoplasms; Skin Neoplasms
PubMed: 37930688
DOI: 10.1167/iovs.64.14.6 -
Annals of Dermatology Oct 2023The periorbital area plays an important role cosmetically. Periorbital wrinkles are attributed to long-term, repeated use of orbicularis oris muscles and UV-induced...
BACKGROUND
The periorbital area plays an important role cosmetically. Periorbital wrinkles are attributed to long-term, repeated use of orbicularis oris muscles and UV-induced dermal collagen degeneration. Fractional microneedle radiofrequency (RF) treats scars and laxity by creating vertical channels of injury in the dermis, triggering a scarless healing cascade and neocollagenesis.
OBJECTIVE
To evaluate the effect and safety of a novel fractional microneedle RF device on periorbital wrinkles based on several objective indicators.
METHODS
Eleven healthy Korean patients aged 30 to 75 years with periorbital wrinkles were included in this study. Wrinkle grades were evaluated using the Fitzpatrick wrinkle assessment scale (WAS). The melanin and erythema index, transepidermal water loss (TEWL), and three parameters for elasticity were recorded. Skin biopsies were obtained in patients who consented.
RESULTS
All patients exhibited wrinkle improvement in the lateral periorbital area, and two patients also showed efficacy in the lower eyelid area. There was a statistically significant decrease in WAS and a significant improvement in the melanin index of V4 and V5. TEWL also showed a considerable decline on V4 and V5, suggesting that the water content of the skin increased with repeated laser sessions. A peak increase in viscoelasticity and a decrease in retraction time following the first laser application were observed. In the histopathologic examination, the dermis had a denser collagen and elastin content.
CONCLUSION
Microneedle fractional RF resulted in statistically significant long-term clinical improvement of periorbital wrinkles and enhanced pigmentation and skin hydration.
PubMed: 37830418
DOI: 10.5021/ad.22.217 -
BMC Complementary Medicine and Therapies Sep 2023We reported a gastric anti-ulcerogenic effect of the Nigella sativa (L.)-derived herbal melanin (HM) using rat models. However, the molecular mechanisms underlying this...
We reported a gastric anti-ulcerogenic effect of the Nigella sativa (L.)-derived herbal melanin (HM) using rat models. However, the molecular mechanisms underlying this HM gastroprotective effect remain unknown. Cyclooxygenase-2 (COX-2)-catalyzed prostaglandin E2 (PGE2) and toll-like receptor 4 (TLR4)-mediated interleukin-6 (IL-6) production and secretion play major roles in gastric mucosal protection. In the current study, the human gastric carcinoma epithelial cell line AGS was used as a model to investigate the effect of HM on TLR4, COX-2, glycoprotein mucin 4 protein and gene expression using immuno-cyto-fluorescence staining, Western blot technology, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Gastroprotective markers PGE2 and IL-6 production and secretion were also assessed using an enzyme-linked immunosorbent assay (ELISA). Bacterial lipopolysaccharides (LPS), well-known inducers of TLR4, COX-2, PGE2 and IL-6 expression, were used as a positive control. We showed that HM upregulated its main receptor TLR4 gene and protein expression in AGS cells. HM increased, in a dose- and time-dependent manner, the secretion of PGE2 and the expression of COX-2 mRNA and protein, which was detected in the nucleus, cytoplasm and predominantly at the intercellular junctions of the AGS cells. In addition, HM enhanced IL-6 production and secretion, and upregulated the mucin 4 gene expression, the hallmarks of gastroprotection. To check whether HM-induced PGE2 and IL-6 through TLR4 signaling and COX-2 generated, AGS cells were pre-treated with a TLR4 signaling inhibitor TAK242 and the COX-2 inhibitor NS-398. A loss of the stimulatory effects of HM on COX-2, PGE2 and IL-6 production and secretion was observed in TAK242 and NS-398-pre-treated AGS cells, confirming the role of TLR4 signaling and COX-2 generated in the HM gastroprotective effects. In conclusion, our results showed that HM enhances TLR4/COX-2-mediated secretion of gastroprotective markers PGE2 and IL-6, and upregulates mucin 4 gene expression in the human gastric epithelial cell line AGS, which may contribute to the promising beneficial gastroprotective effect of HM for human gastric prevention and treatment.
Topics: Humans; Animals; Rats; Stomach Neoplasms; Melanins; Cyclooxygenase 2; Dinoprostone; Toll-Like Receptor 4; Interleukin-6; Mucin-4
PubMed: 37658354
DOI: 10.1186/s12906-023-04124-3 -
International Journal of Molecular... Aug 2023Melanin produced by melanocytes protects our skin against ultraviolet (UV) radiation-induced cell damage and oxidative stress. Melanin overproduction by hyperactivated...
Melanin produced by melanocytes protects our skin against ultraviolet (UV) radiation-induced cell damage and oxidative stress. Melanin overproduction by hyperactivated melanocytes is the direct cause of skin hyperpigmentary disorders, such as freckles and melasma. Exploring natural whitening agents without the concern of toxicity has been highly desired. In this study, we focused on a strain, ZJ1, isolated from a Chinese centenarian, and we evaluated the anti-melanogenic activity of the distinctive extracts of ZJ1. Our results demonstrated that whole lysate (WL) and bacterial lysate (BL) of ZJ1 ferments efficiently reduce α-melanocyte-stimulating hormone (α-MSH)-induced melanin production in B16-F10 cells as well as the melanin content in zebrafish embryos. BL and WL downregulate melanogenesis-related gene expression and indirectly inhibit intracellular tyrosinase activity. Furthermore, they both showed antioxidant activity in a menadione-induced zebrafish embryo model. Our results suggest that ZJ1 fermentation lysates have application potential as therapeutic reagents for hyperpigmentary disorders and whitening agents for cosmetics.
Topics: Animals; Humans; Antioxidants; Bifidobacterium longum; Bleaching Agents; Centenarians; East Asian People; Hyperpigmentation; Melanins; Zebrafish; Aged, 80 and over
PubMed: 37628988
DOI: 10.3390/ijms241612810 -
The Journal of Biological Chemistry Aug 2023Recent advancements in the treatment of melanoma are encouraging, but there remains a need to identify additional therapeutic targets. We identify a role for microsomal...
Recent advancements in the treatment of melanoma are encouraging, but there remains a need to identify additional therapeutic targets. We identify a role for microsomal glutathione transferase 1 (MGST1) in biosynthetic pathways for melanin and as a determinant of tumor progression. Knockdown (KD) of MGST1 depleted midline-localized, pigmented melanocytes in zebrafish embryos, while in both mouse and human melanoma cells, loss of MGST1 resulted in a catalytically dependent, quantitative, and linear depigmentation, associated with diminished conversion of L-dopa to dopachrome (eumelanin precursor). Melanin, especially eumelanin, has antioxidant properties, and MGST1 KD melanoma cells are under higher oxidative stress, with increased reactive oxygen species, decreased antioxidant capacities, reduced energy metabolism and ATP production, and lower proliferation rates in 3D culture. In mice, when compared to nontarget control, Mgst1 KD B16 cells had less melanin, more active CD8 T cell infiltration, slower growing tumors, and enhanced animal survival. Thus, MGST1 is an integral enzyme in melanin synthesis and its inhibition adversely influences tumor growth.
Topics: Animals; Humans; Mice; Glutathione Transferase; Melanins; Melanoma; Zebrafish; Oxidation-Reduction; Mice, Inbred C57BL; Cell Line, Tumor; Cell Proliferation
PubMed: 37321450
DOI: 10.1016/j.jbc.2023.104920 -
Fish & Shellfish Immunology May 2024Melanin and the process of melanin synthesis or melanogenesis have central roles in the immune system of insects, and production of melanin-synthesizing enzymes from... (Review)
Review
Melanin and the process of melanin synthesis or melanogenesis have central roles in the immune system of insects, and production of melanin-synthesizing enzymes from their haemocytes may be induced following activation through danger signals. Melanin-containing macrophage-like cells have been extensively studied in amphibians and they are also present in reptiles. In fish, melano-macrophages are especially recognized with respect to melano-macrophage centres (MMCs), hypothesized to be analogues of germinal centres in secondary lymphoid organs of mammals and some birds. Melano-macrophages are in addition present in several inflammatory conditions, in particular melanised focal changes, or black spots, in the musculature of farmed Atlantic salmon, Salmo salar. Melanins are complex compounds that may be divided into different forms which all have the ability to absorb and scatter light. Other functions include the quenching of free radicals and a direct effect on the immune system. According to the common view held in the pigment cell community, vertebrate melanin synthesis with melanosome formation may only occur in cells of ectodermal origin. However, abundant information suggests that also myeloid cells of ectothermic vertebrates may be classified as melanocytes. Here, we discuss these opposing views and review relevant literature. Finally, we review the current status on the research concerning melanised focal muscle changes that represent the most severe quality problem in Norwegian salmon production, but also other diseases where melano-macrophages play important roles.
Topics: Animals; Melanins; Fishes; Macrophages; Leukocytes; Melanogenesis; Salmo salar; Fish Diseases; Mammals
PubMed: 38522495
DOI: 10.1016/j.fsi.2024.109523