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Hexose transporters (HXT) play a crucial role in the pathogenicity of Magnaporthe oryzae, serving not only as key facilitators for acquiring and transporting sugar nutrients to support pathogen development, but also as sugar sensors which receive transduction signals. The objective of this study is to investigate the impact of MoHXT1-3 on rice pathogenicity and hexose affinity. MoHXT1-3 deletion mutants were generated using CRISPR/Cas9 technology, and their affinity for hexose was evaluated through yeast complementation assays and electrophysiological experiments in Xenopus oocytes. The results suggest that MoHXT1 does not contribute to melanin formation or hexose transportation processes. Conversely, MoHXT2, despite displaying lower affinity towards the hexoses tested in comparison to MoHXT3, is likely to have a more substantial impact on pathogenicity. The analysis of the transcription profiles demonstrated that the deletion of MoHXT2 caused a decrease in the expression of MoHXT3, whereas the knockout of MoHXT3 resulted in an upregulation of MoHXT2 transcription. It is noteworthy that the MoHXT2M145K variant displayed an incapacity to transport hexoses. This investigation into the functional differences in hexose transporters in Magnaporthe oryzae provides insights into potential advances in new strategies to target hexose transporters to combat rice blast by blocking carbon nutrient supply. [ABSTRACT FROM AUTHOR]

Aspergillus fumigatus is an environmental fungus that can cause life-threatening pulmonary disease. Infections initiate when conidia are inhaled and land deep inside the small airways and alveoli of the lungs, where they interact with epithelial cells. These cells provide a physical barrier and secrete chemokines to attract innate immune cells to the site of infection. Melanin, a key constituent of the conidial cell wall, is required for the establishment of invasive infection due to its ability to inhibit the function of innate immune cells recruited to clear the infection. Here, we provide evidence for an additional mechanism by which A. fumigatus can alter host innate immune responses. In vitro infection of a normal human small airway epithelial cell line (HSAEC1-KT) caused a decrease in extracellular protein levels of CXCL10 and CCL20, two proinflammatory chemokines that are required for the host defense against aspergillosis, despite a dramatic increase in the levels of each mRNA. A. fumigatus depleted recombinant human CXCL10 and CCL20 from medium in the absence of host cells, suggesting that the block in accumulation is downstream of protein translation and secretion. Melanin is both necessary and sufficient for this chemokine-depleting activity because a dihydroxynaphthalene (DHN)-melanin-deficient strain of A. fumigatus is defective in depleting chemokines and purified melanin ghosts retain potent depletion activity. We propose that A. fumigatus, through the action of melanin, depletes important chemokines, thereby dampening the innate immune response to promote infection. IMPORTANCE Aspergillus fumigatus is the major airborne fungal pathogen that affects humans. In order to cause an invasive infection, inhaled spores must avoid killing by innate immune cells that are recruited to the site of infection. Understanding how A. fumigatus achieves immune evasion is important for the development of novel therapeutics. We provide evidence that melanin, a pigment contained in the spore cell wall, can remove certain chemokines from the extracellular space to suppress the host inflammatory response that is responsible for clearing fungal infection.

3D-bioprinted skin-mimicking phantoms with skin colors ranging across the Fitzpatrick scale are reported. These tools can help understand the impact of skin phototypes on biomedical optics. Synthetic melanin nanoparticles of different sizes (70-500 nm) and clusters are fabricated to mimic the optical behavior of melanosome. The absorption coefficient and reduced scattering coefficient of the phantoms are comparable to real human skin. Further the melanin content and distribution in the phantoms versus real human skins are validated via photoacoustic (PA) imaging. The PA signal of the phantom can be improved by: 1) increasing melanin size (3-450-fold), 2) increasing clustering (2-10.5-fold), and 3) increasing concentration (1.3-8-fold). Then, multiple biomedical optics tools (e.g., PA, fluorescence imaging, and photothermal therapy) are used to understand the impact of skin tone on these modalities. These well-defined 3D-bioprinted phantoms may have value in translating biomedical optics and reducing racial bias.

Objectives: Vitamin C (ascorbic acid) is widely used in dermatology for skin depigmentation. However, there are very few clinical studies on the efficacy of vitamin C in gingival depigmentation. This preliminary case series aims to present the clinical effectiveness, histologic changes, and patient-reported outcomes of intraepidermal vitamin C injections (oral mesotherapy) for managing patients with gingival melanin hyperpigmentation. Method and materials: Five patients were administered locally injectable vitamin C (once per week for 4 to 5 visits) in maxillary or mandibular anterior pigmented gingiva. The depigmentation effect was evaluated using the Dummett Oral Pigmentation Index (DOPI) and Gingival Pigmentation Index (GPI). Digital photographs were used to assess gingival luminescence (L*) and pigmented surface area (PSA). Parameters were recorded at baseline and at 1 and 3 months. Melanocyte histopathologic count was determined at baseline and at 3 months. Pain, gingival color change, and patient satisfaction scores were also assessed. Results: Median GPI, DOPI, and PSA were significantly reduced (P ≤ .05) from baseline to 1 month. There was no statistically significant change from 1 month to 3 months. L* value significantly increased from baseline to 3 months. A median pain score of 3 (scale of 0 to 10) was observed on the day of the procedure. A score of 3 (scale of 0 to 4) was reported for the gingival color and scores 3 and 4 (scale of 0 to 4) for the overall patient satisfaction. Conclusion: Oral mesotherapy using locally injectable vitamin C is a nonsurgical, minimally invasive, and efficient technique for gingival depigmentation. Indian patients were satisfied with the gingival color obtained and the overall treatment experience. Clinical importance: As all the branches of medicine, specifically dentistry, direct to minimally invasive approaches, mesotherapy shows great importance to reduce the surgical interventions, especially when esthetic outcomes are needed. Oral mesotherapy using locally injectable vitamin C can be a useful nonsurgical technique for achieving gingival depigmentation in the esthetic zone. [ABSTRACT FROM AUTHOR]

BackgroundDuring the disease cycle, plant pathogenic fungi exhibit a morphological transition between hyphal growth (the phase of active infection) and the production of long-term survival structures that remain dormant during "overwintering." Verticillium dahliae is a major plant pathogen that produces heavily melanized microsclerotia (MS) that survive in the soil for 14 or more years. These MS are multicellular structures produced during the necrotrophic phase of the disease cycle. Polyketide synthases (PKSs) are responsible for catalyzing production of many secondary metabolites including melanin. While MS contribute to long-term survival, hyphal growth is key for infection and virulence, but the signaling mechanisms by which the pathogen maintains hyphal growth are unclear.ResultsWe analyzed the VdPKSs that contain at least one conserved domain potentially involved in secondary metabolism (SM), and screened the effect of VdPKS deletions in the virulent strain AT13. Among the five VdPKSs whose deletion affected virulence on cotton, we found that VdPKS9 acted epistatically to the VdPKS1-associated melanin pathway to promote hyphal growth. The decreased hyphal growth in VdPKS9 mutants was accompanied by the up-regulation of melanin biosynthesis and MS formation. Overexpression of VdPKS9 transformed melanized hyphal-type (MH-type) into the albinistic hyaline hyphal-type (AH-type), and VdPKS9 was upregulated in the AH-type population, which also exhibited higher virulence than the MH-type.ConclusionsWe show that VdPKS9 is a powerful negative regulator of both melanin biosynthesis and MS formation in V. dahliae. These findings provide insight into the mechanism of how plant pathogens promote their virulence by the maintenance of vegetative hyphal growth during infection and colonization of plant hosts, and may provide novel targets for the control of melanin-producing filamentous fungi.

Transcription factors (TFs) bind to the promoters of target genes to regulate gene expression in response to different stimuli. The functions and regulatory mechanisms of transcription factors (TFs) in Verticillium dahliae are, however, still largely unclear. This study showed that a C2H2-type zinc finger TF, VdCf2 (V. dahliae chorion transcription factor 2), plays key roles in V. dahliae growth, melanin production, and virulence. Transcriptome sequencing analysis showed that VdCf2 was involved in the regulation of expression of genes encoding secreted proteins, pathogen-host interaction (PHI) homologs, TFs, and G protein-coupled receptors (GPCRs). Furthermore, VdCf2 positively regulated the expression of VdPevD1 (VDAG_02735), a previously reported virulence factor. VdCf2 thus regulates the expression of several pathogenicity-related genes that also contribute to virulence in V. dahliae. VdCf2 also inhibited the transcription of the Vd276-280 gene cluster and interacted with two members encoding proteins (VDAG_07276 and VDAG_07278) in the gene cluster. IMPORTANCE Verticillium dahliae is an important soilborne phytopathogen which can ruinously attack numerous host plants and cause significant economic losses. Transcription factors (TFs) were reported to be involved in various biological processes, such as hyphal growth and virulence of pathogenic fungi. However, the functions and regulatory mechanisms of TFs in V. dahliae remain largely unclear. In this study, we identified a new transcription factor, VdCf2 (V. dahliae chorion transcription factor 2), based on previous transcriptome data, which participates in growth, melanin production, and virulence of V. dahliae. We provide evidence that VdCf2 regulates the expression of the pathogenicity-related gene VdPevD1 (VDAG_02735) and Vd276-280 gene cluster. VdCf2 also interacts with VDAG_07276 and VDAG_07278 in this gene cluster based on a yeast two-hybrid and bimolecular fluorescence complementation assay. These results revealed the regulatory mechanisms of a pivotal pathogenicity-related transcription factor, VdCf2 in V. dahliae.

PurposeUveal coloboma is a congenital eye malformation caused by failure of the optic fissure to close in early human development. Despite significant progress in identifying genes whose regulation is important for executing this closure, mutations are detected in a minority of cases using known gene panels, implying additional genetic complexity. We have previously shown knockdown of znf503 (the ortholog of mouse Zfp503) in zebrafish causes coloboma. Here we characterize Zfp503 knockout (KO) mice and evaluate transcriptomic profiling of mutant versus wild-type (WT) retinal pigment epithelium (RPE)/choroid.MethodsZfp503 KO mice were generated by gene targeting using homologous recombination. Embryos were characterized grossly and histologically. Patterns and level of developmentally relevant proteins/genes were examined with immunostaining/in situ hybridization. The transcriptomic profile of E11.5 KO RPE/choroid was compared to that of WT.ResultsZfp503 is dynamically expressed in developing mouse eyes, and loss of its expression results in uveal coloboma. KO embryos exhibit altered mRNA levels and expression patterns of several key transcription factors involved in eye development, including Otx2, Mitf, Pax6, Pax2, Vax1, and Vax2, resulting in a failure to maintain the presumptive RPE, as evidenced by reduced melanin pigmentation and its differentiation into a neural retina-like lineage. Comparison of RNA sequencing data from WT and KO E11.5 embryos demonstrated reduced expression of melanin-related genes and significant overlap with genes known to be dynamically regulated at the optic fissure.ConclusionsThese results demonstrate a critical role of Zfp503 in maintaining RPE fate and optic fissure closure.

BackgroundKey cellular players regulating human skin pigmentation include melanocytes in the epidermis that synthesize melanin, neighboring keratinocytes that receive and distribute melanin in the upper layers, and fibroblasts in the dermis that affect overlying melanocytes and keratinocytes. In addition, endocrine factors from the blood supply (endothelial cells) and inflammation-related factors play a role. Thus, new strategies for affecting pigmentation need to consider these multiple cell lines to adequately cover various causes and disease processes associated with hyperpigmentation.MethodsPathophysiologic mechanisms and cellular pathways involved in melanogenesis were thoroughly reviewed with particular emphasis on the cellular interplay involved in the process. A complex system of interlinking and independent pathways was defined and described demonstrating differing pathways for altered pigmentary disorders - melasma associated with endothelial cell interactions; post inflammatory hyperpigmentation associated with keratinocyte inflammatory mediators (PGE2 in particular); and photodamage involving all 4 cell types. In vitro validation studies were then undertaken to define differing cell group gene expression profiles with selected peptides and other active agents. Melanocytic production of pigment was then tested with these agents to identify key potential players capable of limiting pigmentation.ResultsHexapeptide-12 and lactoferrin (melanocytes), Hexapeptide-11 (in keratinocytes), and phosphatidylserine (endothelial cells) were identified as major inhibitors of melanogenesis based on their gene expression profiles. This was confirmed by secondary melanin production tests performed on melanocytic lines. Additional active agents were also identified as inhibitors of melanocytic production of melanin, and together, these constituents formed the basis for a novel formulation for use in pigmentary disorders.ConclusionA comprehensive scientific narrative of the various facets relating to pigmentation has been presented including differing pathways affecting varied cell lines that effect pigment production. Based on this concept, actives were tested using gene expression studies as well as in vitro melanogenic model testing in different cell lines. Using this novel multi-faceted approach, we have selected and validated a series of active agents to be used in a formulation targeting the complex problem of hyperpigmentation. J Drugs Dermatol. 2022;21(11):1206-1220. doi:10.36849/JDD.7013.

Plant-based melanin seems to be abundant, but it did not receive scientific attention despite its importance in plant biology and medicinal applications, e.g. photoprotection, radical scavenging, antimicrobial properties, etc. Date fruit melanin (DM) has complex, graphene-like, polymeric structure that needs characterization to understand its molecular properties and potential applications. This study provides the first investigation of the possible molecular composition of DM. High performance size-exclusion chromatography (HPSEC) suggested that DM contains oligomeric structures (569–3236 Da) and transmission electron microscopy (TEM) showed agglomeration of these structures in granules of low total porosity (10–1000 Å). Nuclear magnetic resonance (NMR) spectroscopy provided evidence for the presence of oligomeric proanthocyanidins and electron paramagnetic resonance (EPR) spectroscopy revealed a g-factor in the range 2.0034–2.005. Density functional theory (DFT) calculations suggested that the EPR signals can be associated with oligomeric proanthocyanidin structures having 4 and above molecular units of (−)-epicatechin. The discovery of edible melanin in date fruits and its characterization are expected to open a new area of research on its significance to nutritional and sensory characteristics of plant-based foods. [ABSTRACT FROM AUTHOR]

The demand for green and non-toxic hair dyes has continued to grow in recent years as the majority of consumers prefer natural and healthy products. There are a series of pigments in nature that are used for color pigmentation and dyeing, such as melanin in animals and curcumin in plants. Accordingly, these nature-inspired novel hair dyes are recognized as having the potential to replace conventional hair dyes for their bio-friendly and less irritating properties. Although several nature-inspired hair dye products and their potential properties, including antistatic, antioxidant, and antibacterial properties, have been proposed, their complex pigmentation mechanisms are not fully understood. The present feature article covers several nature-inspired pigments and strives to summarize the possible pigmentation mechanisms for hair dyeing. A special focus was given to the color-tuning techniques of these novel hair dyes, such as optimization of polymerization, pigment compounding, and tuning of the energy level structure. [ABSTRACT FROM AUTHOR]

A novel halotolerant actinobacterium, designated as RG38T, capable of producing black extracellular melanin pigment on SP2 agar, was isolated from the roots of Tagetes patula. Comparative analysis of the 16S rRNA gene sequence revealed the highest similarity to Streptomyces collinus NBRC 12759T (99.3%). Phylogenetic analysis showed that strain RG38T clustered within the genus Streptomyces forming a monophyletic cluster with its close relatives. The average nucleotide identity (ANI), digital DNA-- DNA hybridization (dDDH), and amino-acid identity (AAI) values between strain RG38T and related species within the genus Streptomyces were below the standard threshold for prokaryotic species delineation. The DNA G + C content of the strain RG38T was determined to be 73.3%. The genome size measured 7,150,598 bp comprising 17 contigs and encompassed 6,053 protein coding genes. AntiSMASH analysis of the whole genome revealed 35 putative biosynthetic gene clusters (BGCs) responsible for various secondary metabolites. Among these clusters, two gene clusters exhibited 100% similarity to the chromomycin A3, albaflavenone, and anthracimycin, respectively. These compounds were reported to possess significant anticancer and antibacterial activities. LC--MS-based analysis, coupled with further isolation studies, confirmed the production of chromomycins A2 (1), A3 (2), and their derivatives, along with their antibiotic activities. These findings underscore the potential of this novel strain as a novel resource for the discovery of diverse antimicrobial compounds. This study is the first to report an antimicrobial compound producing Streptomyces species isolated from medicinal plant T. patula. Based on a polyphasic study, the strain RG38T isolated from an unexplored habitat with a high potential for new natural products represents a novel species within the genus Streptomyces. Accordingly, we propose the name Streptomyces tagetis sp. nov. for this novel species, with the type strain is RG38T (=KCTC 49624T = BRC 15113T). [ABSTRACT FROM AUTHOR]

The document is the contents list for the journal "Chemical Communications" published on March 7, 2024. It includes articles on various topics such as the analysis of carbon nanomaterials, engineering drug delivery particles, and the design of fluorescent frameworks for biological sensing. The journal is published by The Royal Society of Chemistry, a leading chemistry community that connects the world with the chemical sciences. The document also mentions approved training courses and provides information on upcoming events and professional development opportunities. [Extracted from the article]

Melanin is a biopolymer pigment that plays a central role in skin photoprotection. Its extensive chemical and dynamical heterogeneity imparts this property through a broad featureless ultraviolet/visible absorption spectrum. Conventionally, the rational design of synthetic photoprotective pigments revolves around establishing the structure-spectra correlation and developing biomimetic materials with desired optical properties. This approach fails to explain the mechanistic details of melanin's absorption spectrum because it arises from an ensemble of structures rather than a local minimum on the potential energy surface. Here, we propose an inverse design approach to elucidate the contributions of dominant chromophoric units in various wavelength domains of the melanin spectrum. [ABSTRACT FROM AUTHOR]

The Derzhavin's sculpin (Radulinopsis derzhavini Soldatov et Lindberg, 1930) is a psychrolutids species that leads a cryptic life in coastal waters of the Japan Sea and the southern Okhotsk Sea. To date, larvae of this species have remained unknown; therefore, their biology is poorly understood. In the present study, the early developmental stages of R. derzhavini are described for the first time. In Peter the Great Bay, Japan Sea, this species is characterized by a spring spawning season (May) and a short pelagic period of larval development, usually from mid‐May to the last 10 days of June. Species identification of the described larvae was confirmed by incubation, rearing of larvae in captivity, and genotyping of a fragment of the mitochondrial cytochrome c oxidase I (COI) gene. In addition, the development of pigmentation in larvae of this and related species was compared. Morphological analysis of both adults and larvae, together with complementary molecular genetics, confirms the previously obtained conclusions that the species of the genera Radulinopsis, Radulinus, Asemichthys, and Astrocottus form a natural group with monophyly by all types of data. [ABSTRACT FROM AUTHOR]

The melanin structure in Cephalopods comprises multi-compound structures, including Tyrosinase-A and Tyrosinase-B. These structures exhibit positivity for H&E stain in some stages and bromophenol blue stain in others. Other components are positive for H&E stains as amylase and peptides of holocrine comments, such as Gamma p.p.t and Gamma melodine, which are rich in ink of Octopus vulgaris and cause color blindness for prey during the predation process of animal. The Octopus vulgaris has numerous inking colors, such as brown and deep brown color, released during the escape from predation animals. During this process, the light falls on the skin, and melanin pigments give deep brown color by mixing the ink with amylase enzymes. The melanin mechanism in all organisms is similar to each other's in the animal kingdom except insects, where it is produced differently. Additionally, melanin pigments are only retained in the upper epidermis from bacterial reactions. The knowledge of the mechanism of melanin formations is highly important for treating dermatology diseases in humans and reducing the risk of skin cancer. [ABSTRACT FROM AUTHOR]

Melanins are complex, polymeric pigments with interesting properties like UV-light absorbance ability, metal ion chelation capacity, antimicrobial action, redox behaviors, and scavenging properties. Based on these characteristics, melanins might be applied in different industrial fields like food packaging, environmental bioremediation, and bioelectronic fields. The actual melanin manufacturing process is not environmentally friendly as it is based on extraction and purification from cuttlefish. Synthetic melanin is available on the market, but it is more expensive than animal-sourced pigment and it requires long chemical procedures. The biotechnological production of microbial melanin, instead, might be a valid alternative. Streptomycetes synthesize melanins as pigments and as extracellular products. In this review, the melanin biotechnological production processes by different Streptomyces strains have been revised according to papers in the literature. The different fermentation strategies to increase melanin production such as the optimization of growth conditions and medium composition or the use of raw sources as growth substrates are here described. Diverse downstream purification processes are also reported as well as all the different analytical methods used to characterize the melanin produced by Streptomyces strains before its application in different fields. [ABSTRACT FROM AUTHOR]

Background: Cutaneous melanoma arises from skin melanocytes and has a high risk of metastatic spread. Despite better prevention, earlier detection, and the development of innovative therapies, melanoma incidence and mortality increase annually. Major clinical risk factors for melanoma include fair skin, an increased number of nevi, the presence of dysplastic nevi, and a family history of melanoma. However, several external inducers seem to be associated with melanoma susceptibility such as environmental exposure, primarily unprotected sun experience, alcohol consumption, and heavy metals. In recent years, epidemiological studies have highlighted a potential risk of β-hexachlorocyclohexane (β-HCH), the most studied organochlorine pesticide, causing cancer induction including melanoma. Methods: We evaluated in vitro the impact of this pollutant on epidermal and dermal cells, attempting to describe mechanisms that could render cutaneous cells more prone to oncogenic transformation. Results: We demonstrated that β-HCH impacts melanocyte biology with a highly cell-type specific signature that involves perturbation of AKT/mTOR and Wnt/β-catenin signaling, and AMPK activation, resulting in lowering energy reserve, cell proliferation, and pigment production. Conclusions: In conclusion, long-term exposure to persistent organic pollutants damages melanocyte metabolism in its function of melanin production with a consequent reduction of melanogenesis indicating a potential augmented skin cancer risk. [ABSTRACT FROM AUTHOR]

Chromoblastomycosis is a chronic granulomatous subcutaneous fungal disease caused mainly by Fonsecaea monophora in southern China. Melanin is an important virulence factor in wild strain (Mel+), and the strains lack of the polyketide synthase gene is a melanin-deficient mutant strain (Mel-). We investigated the effect of melanin in F. monophora on Dectin-1 receptor-mediated immune responses in macrophages. Conidia and tiny hyphae of Mel+ and Mel- were co-cultured with THP-1 macrophages expressing normal or low levels of Dectin-1. Compare the killing rate, phagocytosis rate, and expression levels of the inflammatory cytokines tumour necrosis factor-α, interleukin-1β, interleukin-6, and nitric oxide in each group. The results showed that the killing rate, phagocytosis rate, and pro-inflammatory factor levels of Mel+ infected macrophages with normal expression of Dectin-1 were lower than those of Mel-. And the knockdown of Dectin-1 inhibited the phagocytic rate, killing rate, and proinflammatory factor expression in macrophages infected with Mel+ and Mel-. And there was no significant difference in the above indexes between Mel+ and Mel- groups in Dectin-1 knockdown macrophages. In summary, the study reveals that melanin of F. monophora inhibits the immune response effect of the host by hindering its binding to Dectin-1 on the surface of macrophage, which may lead to persistent fungal infections. [ABSTRACT FROM AUTHOR]

Background: Recent in vitro and in vivo studies have suggested that the elastin peptide improves the skin's biophysical properties, enhancing the proliferation of fibroblasts and elastin synthesis, resulting in anti‐aging properties. Therefore, we conducted a randomized, double‐blinded, placebo‐controlled study to clinically evaluate the effect of elastin peptide intake on human skin. Materials and Methods: Healthy adult participants (N = 100) were randomly assigned to receive a test product containing 100 mg of Bonito elastin peptide (VGPG Elastin®) or placebo. In this study, all participants were Asian from Korea. The parameters of skin wrinkles, hydration, and brightening (melanin index) were measured at baseline and 4, 8, and 12 weeks after intervention. Results: The average skin roughness, maximum peak‐to‐valley values, maximum peak height of the wrinkle, maximum valley depth of the wrinkle, average maximum height of the wrinkle, and eye wrinkle volume improved considerably in the test group compared with the placebo after 12 weeks of intervention. Skin hydration was enhanced, and the melanin index was significantly lower in the test group than in the placebo group. No participant experienced adverse events related to the test product. Conclusion: Oral consumption of Bonito elastin peptide (VGPG Elastin®) reduced fine wrinkles, enhanced skin moisture, and decreased melanin index without significant adverse effects and may be a promising anti‐wrinkle, anti‐dryness, and anti‐pigmentation treatment. [ABSTRACT FROM AUTHOR]

Background and Objective: Skin thermal diffusivity plays a crucial role in various applications, including laser therapy and cryogenic skin cooling.This study investigates the correlation between skin thermal diffusivity and two important skin parameters, melanin content and erythema, in a cohort of 102 participants. Methods: An in‐house developed device based on transient temperature measurement was used to assess thermal diffusivity at different body locations. Melanin content and erythema were measured using a colorimeter. Statistical analysis was performed to examine potential correlations. Results: The results showed that the measured thermal diffusivity values were consistent with previous reports, with variations observed among subjects. No significant correlation was found between thermal diffusivity and melanin content or erythema. This suggests that other factors, such as skin hydration or epidermis thickness, may have a more dominant influence on skin thermal properties. Conlcusion: This research provides valuable insights into the complex interplay between skin thermal properties and physiological parameters, with potential implications for cosmetic and clinical dermatology applications. [ABSTRACT FROM AUTHOR]

A delicate balance between photon absorption for vision and the protection of photoreceptors from light damage is pivotal for ocular health. This equilibrium is governed by the lightabsorbing 11-cis-retinylidene chromophore of visual pigments, which, upon bleaching, transforms into all-trans-retinal and undergoes regeneration through an enzymatic pathway, named the visual cycle. Chemical side reactions of retinaldehyde during the recycling process can generate by-products that may result in a depletion of retinoids. In our study, we have clarified the crucial roles played by melanin pigmentation and the retinoid transporter STRA6 in preventing this loss and preserving the integrity of the visual cycle. Our experiments initially confirmed that consecutive green and blue light bleaching of isolated bovine rhodopsin produced 9-cis and 13-cis retinal. The same unusual retinoids were found in the retinas of mice exposed to intense light, with elevated concentrations observed in albino mice. Examining the metabolic fate of these visual cycle byproducts revealed that 9-cis-retinal, but not 13-cis-retinal, was recycled back to all-trans-retinal through an intermediate called isorhodopsin. However, investigations in Stra6 knockout mice unveiled that the generation of these visual cycle byproducts correlated with a light-induced loss of ocular retinoids and visual impairment. Collectively, our findings uncover important novel aspects of visual cycle dynamics, with implications for ocular health and photoreceptor integrity. [ABSTRACT FROM AUTHOR]

Background: Tocopherols are well‐known antioxidant and moisturizing agent. Tocopherol succinate (TS) are widely used in many skin products especially used in anti‐aging and skin whitening product formulation. Aim: We previously reported the successful synthesis and preliminary characterizations of stable TS ethosomal gels (TSEG) (DOI: 10.1111/jocd.14907). Herein, we develop and further characterize TSEG to enhance the stability of the developed formulation with increased permeation through skin. Methods: Cold method technique was used to prepare TS ethosomes. The developed ethosomal vesicle size was 250 nm, which allowed TS to penetrate through the stratum corneum layer and act on melanocytes. For stability study was assessed by thermogravimetric analysis (TGA) by placing TSEG and unloaded/control ethosomal gel (CEG) at various temperature conditions, that is, 8°C, 25°C, 40°C, and 40°C ± 75% RH for 3 months. Organoleptic evaluation was done in terms of color, odor, and phase separation. Transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FTIR), x‐ray diffraction spectroscopy (XRD), zeta potential (ZP) and particle size (PS) was used for TSEG physical characterizations. In vitro dissolution and ex‐vivo permeation studies (using Franz diffusion cell) were performed for both TSEG and CEG formulations. Human women (N = 34) were used to evaluate in vivo biophysical parameters including erythema, melanin, moisture content, sebum level, and skin elasticity. Results: Developed formulation was highly thermostable during the 3 months. Erythema, melanin, and sebum level decreased while marked improvement (p < 0.05) in moisture content and elasticity have been observed for the developed TSEG. Conclusion: The developed TSEG formulation was found to be efficient, safe (no adverse effects observed), stable (at least for 3 months), and easy to use for topical application with improved skin complexation and skin integrity. [ABSTRACT FROM AUTHOR]

This article discusses the development of topical therapeutics for the treatment of UV-induced skin hyperpigmentary disorders. The researchers used a screening tool to identify compounds that inhibit melanogenesis, the process of melanin synthesis. They engineered small-molecule analogues of a compound called altiratinib, which showed dose-dependent inhibitory action on melanogenesis but had cytotoxicity at higher concentrations. The researchers designed new compounds that demonstrated comparable or better efficacy in reducing melanin content without cytotoxicity. These compounds also showed enhanced skin permeability and were effective in reducing melanin content in mouse and human skin cultures. The findings suggest that these compounds have the potential to be developed into safe and potent topicals for the treatment of hyperpigmentary diseases. [Extracted from the article]

Introduction: The skin is the largest organ in body subjected to external and internal stressors. Methyl methacrylate compounds have proven to be hazardous in many professionals dealing with them. These compounds are mainly used by dentists, nail salon technicians and some orthopedic surgeons. Aim of Work: to explore the cellular alterations occurring in the skin at the histological and ultrastructural levels due to usage of methyl methacrylate compounds. Material and Methods: Twenty mature male albino rats weighing 200 grammes were used for 2 weeks. The skin on the abdominal region of each rat was shaved. Rats were divided into 2 groups: Control (without intervention) and experimental (topically administered a 2 ml of methyl acrylate). Results: Sections of the experimental group displayed thinning of the epidermis with relatively increased thickness of keratin layer. The dermis showed wide spacing of collagen fibres. Increased hair follicles and sebaceous glands was noted. Collagen bundles appeared loosely arranged in Masson's trichrome sections. Experimental group displayed marked loss of elastic fibres in sections stained with Orcein. Strong immunostaining to iNOS in epidermal melanocytes was also seen. Ultrastructural study showed keratinocytes with multiple cytoplasmic vacuoles. Melanocytes also revealed cytoplasmic extensions containing melanin granules. Dermis of skin displayed a degenerating fibroblast. Morphometric analysis confirmed the microscopic findings. Conclusion: Several cellular effects of methyl methacrylate compounds on adult male albino rats' skin was demonstrated in the current work. It is highly advised that further research be done on the many methods that may be utilized to safeguard employees from such threats. [ABSTRACT FROM AUTHOR]

How and why certain groups become speciose is a key question in evolutionary biology. Novel traits that enable diversification by opening new ecological niches are likely important mechanisms. However, ornamental traits can also promote diversification by opening up novel sensory niches and thereby creating novel inter-specific interactions. More specifically, ornamental colors may enable more precise and/or easier species recognition and may act as key innovations by increasing the number of species-specific patterns and promoting diversification. While the influence of coloration on diversification is well-studied, the influence of the mechanisms that produce those colors (e.g. pigmentary, nanostructural) is less so, even though the ontogeny and evolution of these mechanisms differ. We estimated a new phylogenetic tree for 121 sunbird species and combined color data of 106 species with a range of phylogenetic tools to test the hypothesis that the evolution of novel color mechanisms increases diversification in sunbirds, one of the most colorful bird clades. Results suggest that: (1) the evolution of novel color mechanisms expands the visual sensory niche, increasing the number of achievable colors, (2) structural coloration diverges more readily across the body than pigment-based coloration, enabling an increase in color complexity, (3) novel color mechanisms might minimize trade-offs between natural and sexual selection such that color can function both as camouflage and conspicuous signal, and (4) despite structural colors being more colorful and mobile, only melanin-based coloration is positively correlated with net diversification. Together, these findings explain why color distances increase with an increasing number of sympatric species, even though packing of color space predicts otherwise. [ABSTRACT FROM AUTHOR]

The total melanin synthesis in the skin depends on various melanogenic factors, including the number of viable melanocytes, the level of melanogenic enzymes per cell, and the reaction rate of the enzymes. The purpose of this study is to examine the effects of L-cysteine (L-Cys), L-ascorbic acid (L-AA), and their derivatives on the tyrosinase (TYR) activity and autoxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) in vitro and the viability and melanin synthesis of B16/F10 cells under different conditions. L-Cysteinamide (C-NH2), glutathione (GSH), L-Cys, L-AA, and N-acetyl L-cysteine (NAC) inhibited the catalytic activity of TYR in vitro. L-AA, C-NH2, L-ascorbic acid 2-O-glucoside (AAG), and 3-O-ethyl L-ascorbic acid (EAA) inhibited the autoxidation of L-DOPA in vitro. L-DOPA exhibited cytotoxicity at 0.1 mM and higher concentrations, whereas L-tyrosine (L-Tyr) did not affect cell viability up to 3 mM. L-AA, magnesium L-ascorbyl 2-phosphate (MAP), and L-Cys attenuated the cell death induced by L-DOPA. C-NH2 decreased the intracellular melanin level at the basal state, whereas L-AA, MAP, and AAG conversely increased it. C-NH2 reduced the number of darkly pigmented cells via in situ L-DOPA staining, whereas L-AA, MAP, GSH, and AAG increased it. C-NH2 decreased the intracellular melanin level at the alpha-melanocyte-stimulating hormone (α-MSH)-stimulated state, while NAC and GSH increased it. L-AA and C-NH2 decreased the intracellular melanin level at the L-Tyr-stimulated state, but NAC and GSH increased it. L-Ascorbyl tetraisopalmitate (ATI) showed no or minor effects in most experiments. This study suggests that L-AA can either promote or inhibit the different melanogenic factors, and C-NH2 can inhibit the multiple melanogenic factors consistently. This study highlights the multifaceted properties of L-Cys, L-AA, and their derivatives that can direct their therapeutic applications in hyperpigmentation, hypopigmentation, or both disorders. [ABSTRACT FROM AUTHOR]

The article explores the concept of "brownness" and its implications in terms of race, politics, and coalition-building. The author reflects on their own experiences as an East Asian femme in the United Kingdom and the complexities of identifying as "brown" in a racialized society. They discuss the intersections of colorism, classism, and anti-Blackness, as well as the challenges of solidarity and navigating beauty standards. The article also highlights the importance of community care and support, as exemplified by the "PoC Skincare" Facebook group. [Extracted from the article]

This study aimed to evaluate the potential of Dendropanax morbifera Leveille (D. morbifera) extract as a natural melanin depigmentation agent to achieve skin whitening. Treating α-MSH-stimulated B16-F10 cells with the extract effectively inhibited melanin production and tyrosinase activity. The cellular metabolic profiles were analyzed to understand the mechanisms underlying the whitening-related metabolic processes. We identified 29 metabolites that were significantly altered in the α-MSH-stimulated B16-F10 cells. The melanin-synthesis-related pathways that were downregulated included phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism. Simultaneously, alanine, aspartate, and glutamate metabolism; arginine and proline metabolism; arginine biosynthesis; butanoate metabolism; glutathione metabolism; and glyoxylate and dicarboxylate metabolism were upregulated. We found that the optimal extract concentration of 0.2 mg/mL showed the highest efficacy in reversing the alterations to the metabolite levels and metabolic pathways. Moreover, D. morbifera extract exerted low cytotoxicity and high efficacy in inhibiting melanin production. Thus, D. morbifera extract is a potential melanin inhibitor with application in the development of whitening cosmetics. [ABSTRACT FROM AUTHOR]

An experiment was conducted to evaluate the microencapsulated formulation of lyophilized spore crystal aggregate of native isolate BGC-1 and reference isolate HD-1 against second instar larvae of Helicoverpa armigera. The results revealed that the microcapsule diameter ranged from 3.2 to 8.3 µm. Median lethal concentrations of the BGC-1 and Bt-HD1 were 0.66 g/l and 0.50 g/l respectively. UV protectants viz., melanin and para-aminobenzoic acid were evaluated by exposing microencapsulated Bacillus thuringiensis to UV A light at 365nm. Among four microencapsulated formulations, BGC-1 with melanin recorded significantly highest mortality of 95.00 per cent at 0h exposure, as time increased, the mortality decreased and HD-1 was on par with BGC-1. [ABSTRACT FROM AUTHOR]

Owing to the growing need for natural materials in different fields, studying melanin production from biological sources is imperative. In the current study, the extracellular melanin pigment was produced by the fungus Curvularia soli AS21 ON076460. The factors that affect the production of melanin were optimized by the Plackett-Burman design (P-BD). The effect of gamma irradiation on melanin productivity was investigated. The maximum melanin yield (3.376 mg/L) was elicited by a stimulus of gamma irradiation at 1.0 kGy. The results evoked that, Curvularia soli AS21 ON076460 melanin exhibited excellent antimicrobial activity against all tested bacteria and fungi. Klebsiella pneumoniae ATCC 13883 and P. digitatum were mostly affected by melanin registering the inhibition zone diameters of 37.51 ± 0.012 and 44.25 ± 0.214 mm, respectively. Moreover, Curvularia soli AS21 ON076460 melanin indicated a significant antiviral efficacy (77% inhibition) of Herpes simplex virus (HSV1). The melanin pigment showed antioxidant activities with IC50 of 42 ± 0.021 and 17 ± 0.02 µg/mL against DPPH and NO, respectively. Melanin had cytotoxic action against human breast cancer and skin cancer cell lines (Mcf7and A431) as well as exerting a low percentage of cell death against normal skin cell lines (Hfb4). Melanin was effective in wound management of human skin cells by 63.04 ± 1.83% compared with control (68.67 ± 1.10%). The novelty in the study is attributed to the possibility of using gamma rays as a safe method in small economic doses to stimulate melanin production from the fungi that have been isolated. In summary, melanin produced from fungi has significant biological activities that encourage its usage as a supportive medical route. [ABSTRACT FROM AUTHOR]

Melanoma is a malignant skin tumor. This study aimed to explore and assess the effect of novel biomarkers on the progression of melanoma. Differently expressed genes (DEGs) were screened from GSE3189 and GSE46517 datasets of Gene Expression Omnibus database using GEO2R. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted based on the identified DEGs. Hub genes were identified and assessed using protein–protein interaction networks, principal component analysis, and receiver operating characteristic curves. Quantitative real-time polymerase chain reaction was employed to measure the mRNA expression levels. TIMER revealed the association between aldehyde dehydrogenase 2 (ALDH2) and tumor immune microenvironment. The viability, proliferation, migration, and invasion were detected by cell counting kit-8, 5-ethynyl-2′-deoxyuridine, wound healing, and transwell assays. Total 241 common DEGs were screened out from GSE3189 and GSE46517 datasets. We determined 6 hub genes with high prediction values for melanoma, which could distinguish tumor samples from normal samples. ALDH2, ADH1B, ALDH3A2, DPT, EPHX2, and GATM were down-regulated in A375 and SK-MEL-2 cells, compared with the human normal melanin cell line (PIG1 cells). ALDH2 was selected as the candidate gene in this research, presenting a high diagnostic and predictive value for melanoma. ALDH2 had a positive correlation with the infiltrating levels of immune cells in melanoma microenvironment. Overexpression of ALDH2 inhibited cell viability, proliferation, migration, and invasion of A375/SK-MEL-2 cells. ALDH2 is a new gene biomarker of melanoma, which exerts an inhibitory effect on melanoma. [ABSTRACT FROM AUTHOR]

Melanin, the most abundant skin chromophore, is produced by melanocytes and is one of the key components responsible for mediating the skin's response to ultraviolet radiation (UVR). Because of its antioxidant, radical scavenging, and broadband UV absorbing properties, melanin reduces the penetration of UVR into the nuclei of keratinocytes. Despite its long-established photoprotective role, there is evidence that melanin may also induce oxidative DNA damage in keratinocytes after UV exposure and therefore be involved in the development of melanoma. The present work aimed at evaluating the dependence of UV-induced DNA damage on melanin content and distribution, using reconstructed human epidermis (RHE) models. Tanned and light RHE were irradiated with a 233 nm UV-C LED source at 60 mJ/cm2 and a UV lamp at 3 mJ/cm2. Higher UV-mediated free radicals and DNA damage were detected in tanned RHE with significantly higher melanin content than in light RHE. The melanin distribution in the individual models can explain the lack of photoprotection. Fluorescence lifetime-based analysis and Fontana–Masson staining revealed a non-homogeneous distribution and absence of perinuclear melanin in the tanned RHE compared to the in vivo situation in humans. Extracellularly dispersed epidermal melanin interferes with photoprotection of the keratinocytes. [ABSTRACT FROM AUTHOR]

Feathers comprise a series of evolutionary innovations but also harbour colour, a key biological trait known to co‐vary with life history or complex traits. Those relationships are particularly true in melanin‐based pigmentation species due to known pleiotropic effects of the melanocortin pathway – originating from melanin‐associated phenotypes. Here, we explore the molecular basis of melanin colouration and expected co‐variation at the molecular level in the melanin‐based, colour polymorphic system of the tawny owl (Strix aluco). An extensive body of literature has revealed that grey and brown tawny owl colour morphs differ in a series of life history and behavioural traits. Thus, it is plausible to expect co‐variation also at molecular level between colour morphs. To investigate this possibility, we assembled the first draft genome of the species against which we mapped ddRADseq reads from 220 grey and 150 brown morphs – representing 10 years of pedigree data from a population in Southern Finland – and explored genome‐wide associations with colour phenotype. Our results revealed putative molecular signatures of cold adaptation strongly associated with the grey phenotype, namely, a non‐synonymous substitution in MCHR1, plus 2 substitutions in non‐coding regions of FTCD and FAM135A whose genotype combinations obtained a predictive power of up to 100% (predicting grey colour). These suggest a molecular basis of cold environment adaptations predicted to be grey‐morph specific. Our results potentially reveal part of the molecular machinery of melanin‐associated phenotypes and provide novel insights towards understanding the functional genomics of colour polymorphism in melanin‐based pigmented species. [ABSTRACT FROM AUTHOR]

Guppies are small tropical fish with brightly colored bodies and variable tail shapes. There are two phenotypes of domestic guppy eye color: red and black. The wild type is black-eyed. The main object of this study was to identify candidate genes for the red-eyed phenotype in domestic guppies. We hope to provide molecular genetic information for the development of new domestic guppy strains. Additionally, the results also contribute to basic research concerning guppies. In this study, 121 domestic guppies were used for genomic analysis (GWAS), and 44 genes were identified. Furthermore, 21 domestic guppies were used for transcriptomic analysis, and 874 differentially expressed genes (DEGs) were identified, including 357 upregulated and 517 downregulated genes. Through GO and KEGG enrichment, we identified some important terms or pathways mainly related to melanin biosynthesis and ion transport. qRT-PCR was also performed to verify the differential expression levels of four important candidate genes (TYR, OCA2, SLC45A2, and SLC24A5) between red-eyed and black-eyed guppies. Based on the results of genomic and transcriptomic analyses, we propose that OCA2 is the most important candidate gene for the red-eyed phenotype in guppies. [ABSTRACT FROM AUTHOR]

The core pathological event in Parkinson's disease (PD) is the specific dying of dopamine (DA) neurons of the substantia nigra pars compacta (SNc). The reasons why SNc DA neurons are especially vulnerable and why idiopathic PD has only been found in humans are still puzzling. The two main underlying factors of SNc DA neuron vulnerability appear related to high DA production, namely (i) the toxic effects of cytoplasmic DA metabolism and (ii) continuous cytosolic Ca2+ oscillations in the absence of the Ca2+-buffer protein calbindin. Both factors cause oxidative stress by producing highly reactive quinones and increasing intra-mitochondrial Ca2+ concentrations, respectively. High DA expression in human SNc DA neuron cell bodies is suggested by the abundant presence of the DA-derived pigment neuromelanin, which is not found in such abundance in other species and has been associated with toxicity at higher levels. The oxidative stress created by their DA production system, despite the fact that the SN does not use unusually high amounts of energy, explains why SNc DA neurons are sensitive to various genetic and environmental factors that create mitochondrial damage and thereby promote PD. Aging increases multiple risk factors for PD, and, to a large extent, PD is accelerated aging. To prevent PD neurodegeneration, possible approaches that are discussed here are (1) reducing cytoplasmic DA accumulation, (2) blocking cytoplasmic Ca2+ oscillations, and (3) providing bioenergetic support. [ABSTRACT FROM AUTHOR]

Sepsis, whole‐body inflammation caused by the contamination of blood by bacteria and endotoxins, affects millions of patients annually with high mortality rates. A recent promising approach to treat sepsis involves the removal of bacteria and endotoxins using extracorporeal blood‐cleansing devices. However, poor specificity, slow recognition of pathogens, and high costs remain the main limitations. Here, the melanin, a biologically derived pigment, is reported for the rapid binding of bacteria and endotoxins from the contaminated blood. This novel approach utilizes the specific binding between Zn2+‐loaded melanin and bacteria/endotoxins with minimal nonspecific interactions with human blood components. Melanin contains various chemical functional groups that allow reversible chelation of metallic ions such as Zn2+ via redox reactions. Zn2+ enables rapid and specific binding with bacteria/endotoxins due to the strong electrostatic interactions between Zn2+ and phosphate ions. The presence of various zinc‐binding proteins on the bacterial cell membrane further enhances the binding. The well‐known biocompatibility and low cost make melanin an ideal material to interface with human blood. Zn2+‐charged melanin can remove 90% of E. coli and 100% of endotoxin in PBS and human blood. Zn2+‐melanin also demonstrated excellent hemocompatibility shown by protein adsorption, blood coagulation, and hemolysis tests. [ABSTRACT FROM AUTHOR]

Purpose: To determine the inhibitory effect of A. tricolor extract (ATE) on melanogenesis in UV radiation-exposed B16F10 cells. Methods: Total phenolic and anthocyanin contents of ATE were examined by Folin-Ciocalteu and pH differential methods, respectively. The tyrosinase inhibitory effect of ATE was investigated using LDOPA as a substrate and the suppressive effect of ATE on melanin production was determined in melanoma cells. Furthermore, the antioxidant activity was assessed by DPPH method and reactive oxygen species formation while protein expression levels were evaluated by western blot method. Results: The total phenolic and anthocyanin contents were identified up to 35 mg/g extract and 0.85 mg/g extract, respectively. ATE was found to inhibit both mushroom and cellular tyrosinase at IC50 values of 242.2 ± 9.5 µg/mL and 202.9 ± 11.6 µg/mL, respectively. Moreover, ATE treatment reduced melanin production up to (30 ± 5) % and suppressed p38 MAPK phosphorylation at the concentration of 400 µg/mL. In addition, ATE significantly scavenged DPPH radical with EC50 value of 189.2 ± 8.9 µg/mL and abolished ROS formation in the cells. Conclusion: These results indicate that A. tricolor extract has a potential protective effect against melanin production, suggesting its potential value in skin-lightening formulations. [ABSTRACT FROM AUTHOR]

Objectives: During the coronavirus disease-2019 pandemic, masks have become mandatory for protection against the virus transmitted by breathing. This study examined the impact of surgical masks used daily on civilian facial skin. Materials and Methods: Moisture, elasticity, pore, melanin, acne, wrinkle, and sensitivity parameters of 83 volunteers were measured numerically using an API-100 skin analyzer and camera recordings. Numerical values were compared following the device's algorithm calibrated according to age, gender, and race. Finally, the obtained data were statistically evaluated and compared with the averages. Results: Pore, melanin, acne, and wrinkle parameters were higher without gender discrimination, whereas moisture and elasticity parameters were low. While a significant increase was observed in women for sensitivity, the increase was not statistically significant in men. Conclusion: The negative effects of long-term daily wearing of surgical masks on facial skin were statistically significant. Therefore, taking outdoor breaks during mask use, washing the face intermittently, using moisturizing and purifying cosmetic products, and anti-wrinkle effects have been proposed to reduce the possible defects. [ABSTRACT FROM AUTHOR]

ctive: As a result of the study, branched polysaccharides were isolated from the basidiomycete raw materials of Ganoderma lucidum. It has been established that the isolated fractions contain branched polysaccharides in the form of complexes with melanin. Methods: After purification of polysaccharides by ion-exchange chromatography, two fractions were obtained from basidial raw materials: neutral polysaccharides GW-1 with a yield of 25.71% and anionic polysaccharides GW-2, the yield of which was 5.26%, respectively. The physicochemical properties of the obtained samples were studied by IR and UV spectroscopy. The degree of purity of the obtained fractions of branched polysaccharides was established. Using gas chromatography, one-dimensional (13C NMR, 1H NMR) and two-dimensional (COSY, TOCSY, HSQC, HMBC, NOESY) NMR spectroscopy, the composition and molecular structure of the obtained polysaccharide samples were determined. Results and Discussion: The results showed that the isolated and purified polysaccharides are branched glucans with 1,4,6- and 1,3,6-bonds between glucopyranose units. Pharmacotoxicological studies were carried out on white outbred mice and it was found that the resulting polysaccharides belong to class V, practically non-toxic compounds (LD50³ 2000 mg/kg). Conclusions: Isolated polysaccharides (GW) are promising biologically active components, on the basis of which it is possible to create drugs with hepatoprotective and antitumor activity. [ABSTRACT FROM AUTHOR]

Bird plumage coloration is a complex and multifactorial process that involves both genetic and environmental factors. Diverse pigment groups contribute to plumage variation in different birds. In parrots, the predominant green color results from the combination of 2 different primary colors: yellow and blue. Psittacofulvin, a pigment uniquely found in parrots, is responsible for the yellow coloration, while blue is suggested to be the result of light scattering by feather nanostructures and melanin granules. So far, genetic control of melanin-mediated blue coloration has been elusive. In this study, we demonstrated that feather from the yellow mutant rose-ringed parakeet displays loss of melanosome granules in spongy layer of feather barb. Using whole genome sequencing, we found that mutation in SLC45A2, an important solute carrier protein in melanin synthetic pathway, is responsible for the sex-linked yellow phenotype in rose-ringed parakeet. Intriguingly, one of the mutations, P53L found in yellow Psittacula krameri is already reported as P58A/S in the human albinism database, known to be associated with human OCA4. We further showed that mutations in SLC45A2 gene affect melanin production also in other members of Psittaculidae family such as alexandrine and plum-headed parakeets. Additionally, we demonstrate that the mutations associated with the sex-linked yellow phenotype, localized within the transmembrane domains of the SLC45A2 protein, affect the protein localization pattern. This is the first evidence of plumage color variation involving SLC45A2 in parrots and confirmation of associated mutations in the transmembrane domains of the protein that affects its localization. [ABSTRACT FROM AUTHOR]

Tyrosol (4-hydroxyphenylethanol) is a phenolic compound used in the pharmaceutical and chemical industries. However, current supply methods, such as extraction from natural resources and chemical synthesis, have disadvantages from the viewpoint of cost and environmental protection. Here, we developed a tyrosol-producing Escherichia coli cell factory from a high-tyrosine-producing strain by expressing selected tyrosine decarboxylase-, tyramine oxidase (TYO)-, and medium-chain dehydrogenase/reductase (YahK)-encoding genes. The genes were controlled by the strong T7 promoter and integrated into the chromosome because of the advantages over plasmid-based systems. The strain produced a melanin-like pigment as a by-product, which is suggested to be formed from 4-hydroxyphenylacetaldehyde (a TYO product/YahK substrate). By using a culture medium containing a high concentration of glycerol, which was reported to enhance NADH supply required for YahK activity, the final titer of tyrosol reached 2.42 g/L in test tube-scale cultivation with a concomitant decrease in the amount of pigment. These results indicate that chromosomally integrated and T7 promoter-controlled gene expression system in E. coli is useful for high production of heterologous enzymes and might be applied for industrial production of useful compounds including tyrosine and tyrosol. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Paclitaxel (PTX) is a microtubule‐stabilizing antineoplastic that has been shown to damage healthy tissues like the skin. Hyperpigmentation can be found among the adverse effects caused by PTX, but the literature is limited and the mechanisms driving PTX‐induced pigmentary alterations are unknown. Objectives: This study aimed to describe the pigmentary alterations caused by PTX and to determine the effects of PTX on melanocytes. Methods: Pigmentary skin alterations were measured in 20 gynecological cancer patients under PTX treatment by using specific probes, which determine the melanin index and the pigmentation level. Melanocytes were incubated with paclitaxel to analyze melanogenesis markers gene expression, melanin content, and transcription factors activation. Results: Paclitaxel induced alterations in the skin pigmentation with no visible clinical manifestations. Gynecological cancer patients under paclitaxel treatment had an increase in the melanin index and pigmentation levels. In vitro, PTX exposure to melanocytes increased the expression of melanogenesis markers, melanin content, and induced activation of ERK and MITF. Conclusions: The results suggest that PTX alters pigmentation in patients with no clinically visible manifestations, and these alterations might be driven by its capacity to stimulate melanogenesis on melanocytes through the MITF activation pathway. [ABSTRACT FROM AUTHOR]

Dezhou donkey is one of the representative local breeds in China, which is mainly divided into two strains: Sanfen and Wutou. There are obvious differences in coat color between the two strains. The former shows light points around the eyes, around the muzzle and under the belly, while the latter is completely solid black. In this study, genome‐wide association analysis was performed for the differences in coat color traits between the Sanfen (n = 97) and Wutou (n = 108) strains using a novel donkey 40K liquid chip developed based on GenoBaits technology, to identify genomic regions and causal genes that could explain this variation. We also used FST and The cross‐population composite likelihood ratio test (XPCLR) analyses to explore selected regions related to coat color differences. We identified one significant region on chromosome 15, with the most significant SNP located within the agouti signaling protein (ASIP) gene. At the same time, both FST and XPCLR methods detected the same selected region on chromosome 15, and ASIP was the gene with the strongest signal. ASIP and melanocortin 1 receptor (MC1R) control the ratio of eumelanin to pheomelanin through their protein activity. They are deeply involved in the process of melanosome organation and melanogenesis, thus affecting mammals' coat color variation. We used a range of genome‐wide approach to identify the genetic basis of coat color variation in Dezhou donkeys. The results provide a supplement to the color variation study in Chinese donkeys at the genome‐wide level, and preliminarily verified the reliability of the Molbreeding Donkey No. 1 40K liquid chip. [ABSTRACT FROM AUTHOR]

Background: Facial dark spots remain a significant challenge for the cosmetic industry, in terms of providing effective treatment. Using Line‐field Confocal Optical Coherence Tomography (LC‐OCT), we investigated the internal structural features of photo‐aging spot areas and evaluated the efficacy of a skin‐brightening cosmetic product. Materials and Methods: Twenty‐six Asian female volunteers, aged between 29 and 65 years, applied a cosmetic product on their entire face twice a day for 2 months. LC‐OCT was used to evaluate the dermal‐epidermal junction (DEJ) undulation and the volume density of melanin in the epidermis at D0 and D56. Skin brightening and redness were also assessed by photography (SkinCam). Results: Using LC‐OCT technology, various microscopic dark spot morphologies, spanning from minimally deformed DEJ to complex DEJ patterns, were identified. Dark spots characterized by slight deformities in the DEJ were predominantly observed in the youngest age group, while older volunteers displayed a wavier pattern. Furthermore, a total of 44 spots were monitored to evaluate the brightening product efficacy. A statistically significant reduction in melanin volumetric density of 7.3% in the spots and 12.3% in their surrounding area was observed after 56 days of product application. In line with these results, an analysis of color parameters using SkinCam reveals a significant increase in brightening and decrease in redness in both pigmented spots and the surrounding skin following application. Conclusions: LC‐OCT proves to be a valuable tool for in‐depth dark spots characterization and assessment of skin brightening products, enabling various applications in the field of dermatological sciences. [ABSTRACT FROM AUTHOR]

Background: Treatment of infraorbital dark circles and under‐eye puffiness is challenging due to its multifactorial nature and lack of broadly applicable, effective treatments. A daily skincare treatment option that is multimodal, effective, and tolerable across a broad patient population is an unmet need. Aim: A multicorrective topical eye cream (MTEC) formulated with Tetrahexyldecyl (THD) ascorbate (vitamin C), prebiotic Inula Helenium, bioavailable peptides, botanical extracts, chrysin, and caffeine is hypothesized to improve the appearance of infraorbital dark circles and under‐eye puffiness by targeting microvasculature congestion and permeability, melanin accumulation and hemoglobin degradation‐related pigmentation, and skin health. Methods: An IRB approved, open‐label, 12‐week clinical study set out to evaluate the efficacy and tolerability of the MTEC across a broad patient population including varying ethnicities and Fitzpatrick Skin Types (FST). Female subjects (n = 40) ages 35–60 years old, with moderate‐to‐severe under‐eye dark circles, moderate under‐eye puffiness, and mild‐to‐moderate fine lines were enrolled into the study. Objective (Chromameter, VISIA® imaging, and Laser Doppler) and subjective assessments (clinical grading and self‐assessment questionnaire) were conducted at baseline and post‐baseline timepoints. Results: Thirty‐seven subjects completed the study, and the MTEC efficaciously demonstrated short‐term and long‐term improvements in objective and subjective assessments across a broad patient population. Specifically, the MTEC demonstrated significant improvement of infraorbital dark circles, mainly by the reduction in microvasculature congestion and permeability, melanin, and hemoglobin degradation‐related pigmentation. Conclusion: Topical application of the MTEC may offer an effective and tolerable treatment option for infraorbital dark circles and puffiness. [ABSTRACT FROM AUTHOR]

Background: Oral collagen peptides supplementation was reported to improve skin integrity and counteract skin aging. Aims: A randomized, double‐blinded, placebo‐controlled study was conducted to clinically evaluate the impact of low‐molecular‐weight collagen peptides on the human skin. Patients/Methods: Healthy adult participants (n = 100) were randomly assigned to receive a test product containing low‐molecular‐weight collagen peptides or a placebo. Parameters of skin wrinkles, elasticity, hydration, and whitening (melanin and erythema indexes) were measured at baseline and after 4, 8, and 12 weeks. Results: Compared with the placebo group, the average skin roughness, maximum of all peak‐to‐valley values, maximum peak height of the wrinkle, and average maximum height of the wrinkle were significantly improved in the test group. Parameters of skin elasticity, including overall elasticity, net elasticity, and biological elasticity, were also significantly improved in the test group at Week 12 as compared with the placebo group. Moreover, skin hydration and whitening parameters changed more significantly in the test group than in the placebo group. None of the participants experienced adverse events related to the test product. Conclusions: Taken together, these findings suggest that low‐molecular‐weight collagen peptides supplementation can safely ehance human skin wrinkling, hydration, elasticity, and whitening properties. [ABSTRACT FROM AUTHOR]

Background: The development of effective cosmetic products for the reduction of the signs of skin aging is a complex process which requires an optimized combination of ingredients and specialized systems to deliver the actives to the skin layers. Aim: To evaluate the tolerance and antiaging clinical efficacy of a cosmetic formulation containing a blend of nanoencapsulated antioxidants: ascorbyl palmitate, resveratrol, tocopherol, caffeine, carnosine, and niacinamide. Methods: Clinical efficacy was determined by subjective and instrumental analyses of collagen synthesis by fluorescence spectroscopy, by three‐dimensional imaging analysis of suborbital edema, and by analysis of skin hydration and sebum content by biophysical techniques—Corneometer® and Sebumeter®. Results: The studied formulation was safe and effective for the improvement of skin appearance by increasing collagen synthesis and skin moisturizing and by reducing facial blemishes, swelling, and oiliness. A preclinical exploratory approach using an experimental model of human cell and skin cultures agreed with the observed antiaging effects, identifying mechanisms related to the containment of oxidative stress, reduction of melanin production, increased synthesis of type I procollagen, and regulation of the epidermal cohesion protein filaggrin. Conclusions: The skin benefits obtained resulted from the combination of the ingredients in the formulation and the nanoencapsulation‐based delivery system, which favors the solubility, safety, efficacy, and bioavailability of the preparation to the skin. [ABSTRACT FROM AUTHOR]

Photoaging affects the performance and service life of degradable liquid plastic film. Melanin is a highly effective photoprotectant left by biological evolution. In this paper, melanin was used in liquid mulch film, and the effect of chestnut shell pigment on the performance of carboxymethyl cellulose liquid mulch film was discussed. The results showed that the addition of chestnut shell pigment significantly improved the tensile strength of the plastic film, reduced the elongation at break, made the film loose, increased the pores, and increased the water vapor permeability. The addition of chestnut shell pigment also significantly improved the antioxidant capacity and ultraviolet aging resistance of plastic film. When the mass ratio of chestnut shell pigment to carboxymethyl cellulose was 5: 3, the liquid mulch film could effectively slow down the evaporation of soil water and had good soil water retention performance. Chestnut shell pigment can be used as a cheap and environmentally friendly degradable liquid mulch film photoprotectant. [ABSTRACT FROM AUTHOR]