Types Of Pigments Research Articles

Quantifying pigment features of Thangka Five Buddhas using hyperspectral imaging

Thangka, a masterpiece of Tibetan painting, is renowned for its adept use of natural mineral pigments such as gold, turquoise, and cinnabar, which imbue it with profound artistic and historical significance. Presently, chemical analysis methods relying on microscopic perspectives are prevalent in researching the pigment components of cultural artifacts. However, these methods suffer from quantization gaps and carry the risk of damaging the relics. Hence, in this study, we focus on Thangka Five Buddha as our experimental sample and propose a novel approach utilizing Linear Spectral Mixed Analysis (LSMA) based on Hyperspectral Imaging (HSI) technology to perform quantitative analysis of pigment components at a sub-pixel level. The results indicate the following. 1) A database of spectral curves for 25 representative Thangka pigments was established, covering 196 bands from 393 to 800 nm VIR-NIR range. 2) The LSMA model successfully separated the 13 pigment components of the Thangka at the sub-pixel level, achieving a Root Mean Square Error (RMSE) of 0.0186, which indicates high classification accuracy. 3) The quantitative analysis reveals that 33.07 % of the area is painted using a single pigment, while 56.01 % is painted using a combination of two pigments. Verdigris (18.56 %), malachite (17.52 %), and cinnabar (10.91 %) are the pigment types with the highest proportions among them. Out of the 521 pigment combinations, verdigris and turquoise (4.55 %), malachite and calcite (4.02 %), minium and cinnabar (2.87 %), and turquoise and malachite (2.82 %) are more commonly used. 4) The application of quantitative analysis methods demonstrates significant potential in painting techniques, authentication processes, and establishing historical dating, among other areas of study.

Multi-omics landscape and molecular basis of radiation tolerance in a tardigrade.

Tardigrades are captivating organisms known for their resilience in extreme environments, including ultra-high-dose radiation, but the underlying mechanisms of this resilience remain largely unknown. Using genome, transcriptome, and proteome analysis of Hypsibius henanensis sp. nov., we explored the molecular basis contributing to radiotolerance in this organism. A putatively horizontally transferred gene, DOPA dioxygenase 1 (DODA1), responds to radiation and confers radiotolerance by synthesizing betalains-a type of plant pigment with free radical-scavenging properties. A tardigrade-specific radiation-induced disordered protein, TRID1, facilitates DNA damage repair through a mechanism involving phase separation. Two mitochondrial respiratory chain complex assembly proteins, BCS1 and NDUFB8, accumulate to accelerate nicotinamide adenine dinucleotide (NAD+) regeneration for poly(adenosine diphosphate-ribosyl)ation (PARylation) and subsequent poly(adenosine diphosphate-ribose) polymerase 1 (PARP1)-mediated DNA damage repair. These three observations expand our understanding of mechanisms of tardigrade radiotolerance.

Cutaneous melanoma in situ: a review.

Cutaneous melanoma in situ (MIS), also known as 'stage 0 melanoma', is a collection of malignant melanocytes in the epidermis and epithelial adnexa, without evidence of microinvasion to the papillary dermis. Distinct histologic subtypes include lentigo maligna (LM), superficial spreading (SS) MIS and acral lentiginous (AL) MIS. LM is the most common subtype, usually diagnosed later in life (median age at diagnosis of 66-72 years) and associated with cumulative ultraviolet radiation exposure. SS MIS is associated with intense episodes of sun exposure and is more common on the trunk and extremities. AL MIS is seen in non-hair-bearing skin. Although rare (0.6% of MIS in England), AL MIS is found in higher proportion in more pigmented skin types compared to other MIS subtypes. Most international studies between 1990-2019 report rising incidence for MIS. US data support a deceleration in the rising incidence of LM between 2016-2019. For 2013-2019 in England, the recorded incidence of LM is plateauing, while that of other MIS is rising. Definitive diagnosis of MIS is by histological examination of biopsied skin with immunohistochemistry but can be supported with dermoscopy and reflectance confocal microscopy. Surgical treatment (excision or Mohs micrographic surgery) is the gold standard. Depending on MIS subtype, other options such as cryotherapy, topical imiquimod, radiotherapy, or watchful waiting may be appropriate. The latest 5-year net survival rates in England between 2013-2015 are 98.6% for AL MIS and exceed 100% for all other MIS. This review summarises the aetiology, pathogenesis, epidemiology, diagnosis and management of MIS.

V. Introduction and selection of a new species of Clarkia (C. purpurea) and development of a method for evaluating Clarkia pursh varieties for distinctiveness, uniformity and stability

During 2011–2023 in the south of Western Siberia, with the aim of introducing and selecting a new species of clarkia (C. purpurea), its biological characteristics and morphological characteristics were studied. Based on the data obtained and the use of other species and varieties of the genus Clarkia Pursh. For the first time, a methodology for conducting tests for distinctiveness, uniformity and stability (DUS) for this crop was developed. This technique is applicable to all varieties of the genus Clarkia Pursh, classified into sections: Godetia (C. purpurea (Curtis) A. Nelson & J. F. Macbr.), Phaeostoma (C. unguiculata Lindl.), Rhodanthos (C. amoena (Lehm.) A . Nelson & J. F. Macbr., Clarkia amoena ssp. lindleyi (Douglas) H. F. Lewis & M. Е. Lewis), fireweed family (Onagraceae Juss.). Many species of clarkia are characterized by long-lasting flowering and are promising for floral decoration of urban spaces, as well as for cutting. Most varieties are from very low – up to 25 cm tall, to very high – 96 cm or more; leaves are simple, lanceolate, narrow-lanceolate, wide-lanceolate, ovate, smooth, pubescent. The flowers are very decorative, varying in size from 2.0 to 8.0 cm tall, simple, semidouble, terry and strongly terry with or without fragrance, with a large variability of colors and types of floral pigmentation. Based on the study of the bioecological and morphological properties of the crop under study and in accordance with the rules approved by the Federal State Budgetary Institution “State Varietal Commission”, 36 characteristics were selected by which it is possible to test clarkey varieties. As a result of breeding work, a new variety of C. purpurea, Lilac Fairy, was created. When analyzing crossing, it was established that the lilac (violet) color of flowers is dominant in relation to pale pink (almost white), and when crossing F1 hybrids with light purple color, splitting 15:1 (15 violet from dark purple to pale purple was obtained and 1 is pale pink), which confirms the hypothesis about the polygenic nature of the inheritance of the main color of flowers in C. purpurea. The national methodology RTG/1157/1, created for the first time, for testing the DUS of Clarkia Pursh varieties will serve as a scientific basis for practical breeding.

Pterin-Based Red Coloration Predicts the Outcome of Male-Male Competition in Guinan Toad-Headed Lizard.

Animal coloration offers a unique opportunity to explore the evolutionary mechanisms underlying phenotypic diversity. Conspicuous coloration caused by pigments plays a crucial role in social signaling across multiple species by conveying information about individual quality, social ranks, or reproductive condition. Nevertheless, most previous studies have focused predominantly on colors produced by the exogenous pigments-carotenoids. Pterins are another prevalent group of conspicuous pigments, which can be produced endogenously and have received comparatively little attention. Whether pterin-based colors represent reliable signals remains elusive. The remarkable red ventrolateral coloration exhibited by males of the Guinan toad-headed lizard (Phrynocephalus guinanensis) in the Mugetan Desert presents an ideal model for investigating pterin-based coloration. Through electron microscopy and metabolomic identification, we discovered three types of pterin pigments within xanthophores. Integrating a series of morphological measurements and behavioral experiments, we found that this red coloration was not correlated with body size, bite force, and testosterone level, nor did females show a preference bias toward it. However, the red intensity predicted male-male competition outcomes, with deeper red males being more likely to emerge as winners. Our results indicated that the pterin-based coloration could convey information about male quality, suggesting its potential role in honest signaling, given the vital importance of pterin metabolism in physiological processes. This study provides a novel case into the understanding of pterin-based colors in animals.

Light Color Regulation of Photosynthetic Antennae Biogenesis in Marine Phytoplankton.

Photosynthesis in the world's oceans is primarily conducted by phytoplankton, microorganisms that use many different pigments for light capture. Synechococcus is a unicellular cyanobacterium estimated to be the second most abundant marine phototroph, with a global population of 7 x 1026 cells. This group's success is partly due to the pigment diversity in their photosynthetic light harvesting antennae, which maximize photon capture for photosynthesis. Many Synechococcus isolates adjust their antennae composition in response to shifts in the blue:green ratio of ambient light. This response was named Type 4 chromatic acclimation (CA4). Research has made significant progress in understanding CA4 across scales, from its global ecological importance to its molecular mechanisms. Two forms of CA4 exist, each correlated with the occurrence of one of two distinct but related genomic islands. Several genes in these islands are differentially transcribed by the ambient blue:green light ratio. The encoded proteins control the addition of different pigments to the antennae proteins in blue versus green light, altering their absorption characteristics to maximize photon capture. These genes are regulated by several putative transcription factors also encoded in the genomic islands. Ecologically, CA4 is the most abundant of marine Synechococcus pigment types, occurring in over 40% of the population oceanwide. It predominates at higher latitudes and at depth, suggesting that CA4 is most beneficial under sub-saturating photosynthetic light irradiances. Future CA4 research will further clarify the ecological role of CA4 and the molecular mechanisms controlling this globally important form of phenotypic plasticity.

Extraction of Bacterial Pigments and Evaluation of its Antioxidant Activity

Carotenoid are pigment that exist in a wide variety of plant and microorganism they are characterized by red, yellow or orange coloration .These important pigment play significant role in animal and human health .In contrast to plant production, the advantages of microbial fermentation of carotenoids were lower media cost, fast growth rate of microorganism and the ease of culture control . When the microbial cells are used to produce the color the term refers to ‘microbial pigments’. Different types of pigments extracted from different microbes. In this study, soil and water samples were collected from different areas of MGM University, Chh. Sambhajinagar .Different pigmented colonies were observed on nutrient agar plate .Out of these, the orange and yellow colonies were selected and sub-cultured further to obtain their pure cultures. These samples were inoculated onto nutrient agar plates, and after an incubation period of 24 hours, different colonies were observed on the plates. Out of these, the orange and yellow isolated were selected and sub-cultured further to obtain their pure cultures. After production of the pigment in liquid medium, it was further processed for the extraction of these pigments. Further, antioxidant assay by radical scavenging activity of DPPH was carried out, which revealed that the pigment had an radical scavenging activity of 60% as compared to that of the standard ascorbic acid, which showed radical scavenging activity of 33 %. Thus, the current study can be a useful step for large-scale production of pigments, their purification and application in cosmetic industries

Effects of Pigment Particle Size and Colored Layer Thickness on the Underdrawing Detection in Painted Cultural Heritage Using Near-Infrared Photography

In this study, five types of inorganic pigments were selected, and samples with varying color layer thicknesses were produced following particle size analysis. Hyperspectral imaging was then used to assess the efficiency of underdrawing detection. By comparing infrared images in the near-infrared range(950 to 1700 nm), the study confirmed that particle size and color layer thickness significantly influence underdrawing detection efficiency using infrared photography. Specifically, larger particles within the same color layer thickness demonstrated superior detection efficiency, and the detectable thickness varied according to particle size. The efficiency of underdrawing detection, as measured by the brightness difference(ΔL*) between the base and underdrawing areas, also reflected this pattern. The study successfully established a correlation between pigment particle size, color layer thickness, and underdrawing detection efficiency. These findings are expected to serve as foundational data for detecting underdrawings in painted cultural heritage using Near-Infrared photography, as well as for interpreting pigment application techniques at cultural heritage investigation sites.

The CoNb2O6 pigments for brilliant-blue ceramic decoration at high temperatures over 1273 K

To date, brilliant-blue pigments that can maintain outstanding stability in a corrosive environment over 1273 K are still very desirable in the ceramic industry. We systematically investigated the structural, optical, colorimetric and thermal properties of a novel type of CoNb2O6 pigments, which have the 6-fold coordinated Co2+ as chromophores and high-valent Nb5+ as the mainstay factor for structural stabilization. Effective coloring contribution from different visible-light regions, the coloration mechanism and thermal stability of the pigments applied in glaze at 1273–1473 K are revealed for the first time. The Co2+ cation at the distorted [CoO6] octahedra generates the brilliant blue hue, which can maintain the absolute blueness values, b*, at 30–44 even after glaze calcination at 1273–1423 K. The superb thermal performance in a harsh environment of the CoNb2O6 pigments significantly outperforms the classic CoAl2O4 blue, thereby exhibiting attractive prospects for high-end blue-sky–hued decoration for ceramics.

The divergence of DHN-derived melanin pathways in Metarhizium robertsii.

The important role of dihydroxynaphthalene-(DHN) melanin in enhancing fungal stress resistance and its importance in fungal development and pathogenicity are well-established. This melanin also aids biocontrol fungi in surviving in the environment and effectively infecting insects. However, the biosynthetic origin of melanin in the biocontrol agents, Metarhizium spp., has remained elusive due to the complexity resulting from the divergence of two DHN-like biosynthetic pathways. Through the heterologous expression of biosynthetic enzymes from these two pathways in baker's yeast Saccharomyces cerevisiae, we have confirmed the presence of DHN biosynthesis in M. roberstii, and discovered a novel naphthopyrone intermediate, 8, that can produce a different type of pigment. These two pigment biosynthetic pathways differ in terms of polyketide intermediate structures and subsequent modification steps. Stress resistance studies using recombinant yeast cells have demonstrated that both DHN and its intermediates confer resistance against UV light prior to polymerization; a similar result was observed for its naphthopyrone counterpart. This study contributes to the understanding of the intricate and diverse biosynthetic mechanisms of fungal melanin and has the potential to enhance the application efficiency of biocontrol fungi such as Metarhizium spp. in agriculture.

Oxidative Challenges Do Not Impact Pheomelanin-Dependent Coloration in Male Japanese Quails.

Colorful traits play an important role in animal communication. Melanin-based colorations are the most extended color traits in animals and are produced by two types of endogenous melanic pigments: eumelanins and pheomelanins, the last ones being the least studied in the context of communication. The production of pheomelanin requires a semi-essential amino acid, cysteine, which is also used for the synthesis of an important endogenous antioxidant, glutathione. Hence, it has been proposed that the synthesis of pheomelanin and glutathione may compete for the cysteine available in the organism. In that case, pheomelanic colorations are predicted to be less intense when the individual is facing an oxidative challenge, and therefore, they would provide information on the oxidative status of the bearer. Here, we experimentally evaluated this hypothesis using male Japanese quails (Coturnix japonica) as a model of study, a species with pheomelanin-based plumage in the breast and cheeks. During feather growth, individuals were exposed to one of three possible conditions: Control (saline), an endogenous oxidative challenge (Escherichia coli lipopolysaccharide injections), or an exogenous oxidative challenge (paraquat injections). Contrary to predictions, we found that: (1) Birds from the three groups exhibited less intense pheomelanic colorations in feathers after the experimental manipulation, and the magnitude of this change did not differ among groups. (2) There was no effect of the experimental treatments on the proportion reduced/oxidized glutathione, an index of oxidative status. (3) Lipid peroxidation was lower after the experimental manipulation, with birds exposed to the paraquat challenge experiencing a stronger decline than other groups. (4) Cysteine and total glutathione levels decreased after the experimental manipulation, with no differences per group in the magnitude of the decline. Taken together the results do not support the hypothesis that oxidative status plays a key role at determining the variation in the intensity of pheomelanic colorations.

Bacterial Pigments as a Promising Alternative to Synthetic Colorants: From Fundamentals to Applications.

Pigments find widespread application in the fields of food, medicine, textiles, and cosmetics. At present, synthetic colorants dominate the global pigment market. However, the environmental and health hazards associated with synthetic colorants have spurred extensive research on eco-friendly and safe alternatives. Natural pigments are particularly intriguing for meeting consumer demands and sustainable development, as they not only exhibit various vibrant color shades without discernible toxic side effects but also offer additional healthful features such as antibacterial, antioxidant, anticancer, and antiviral properties compared with their synthetic counterparts. Among natural sources, bacterial strains share distinct advantages for large-scale pigment production because of their intrinsic robustness of cellular metabolic systems. This review comprehensively outlines the bacterial sources, extraction and purification methods, structural characteristics, biological activities, and potential applications of typical pigments, including but not limited to violacein, indigoidine, melanin, carotenoids, prodigiosin, and rhodopsin. Additionally, it underscores the primary obstacles to the development and production of bacterial pigments for commercial applications, discussing feasible strategies for overcoming production bottlenecks. This work also provides valuable insights for the scientific and rational advancement of bacterial pigment development.

Oil-in-water microemulsion of Arthrospira platensis carotenoid as antiphotooxidation in vitamin C beverages

Arthrospira platensis is a blue-green microalgae that has carotenoid as the main pigments, with the largest content being beta-carotene. Carotenoids are a type of pigment that is water insoluble, unstable, and has a limited bioavailability. One of the efforts to improve its solubility and stability, especially with regard to its anti-photooxidation capabilities, is to make it into a microemulsion. This study aimed to develop the most stable oil-in-water (O/W) microemulsion containing carotenoids from A. platensis for use as an antiphotooxidation agent in vitamin C beverages. Microemulsions consist of three distinct phases: oil, water and surfactant. The oil phase consisted of virgin coconut oil (VCO) or palm oil, with 7.5% and 15% and the aqueous phase was distilled water at a concentration of 65% or 80%. The surfactant used a combination of Tween 80, Tween 20, and Span 80 with a final hydrophilic-lipophilic balance or HLB value of 14.5. All microemulsion formulations were incubated for 24 hrs before being tested for stability by centrifugation at 3000 rpm for 30 mins, heating at 105oC for 5 hrs, and storage for 2 and 4 weeks. The resulting turbidity index was used to test the microemulsion's stability. The most stable microemulsion was chosen as a delivery system for carotenoid compounds. The carotenoid microemulsion was also tested by centrifugation, heating, and stability at different pH (6.5 and 4.2) and in varied ratios (1:1, 1:9 and 1:99). The results revealed that the concentration of oil and water phases in the microemulsion formulation influenced the microemulsion's stability. The best formulation obtained was a microemulsion with 7.5% of virgin coconut oil, 80% of water concentration, and surfactant with a ratio of 92:5.5:2.5 (Tween 80: Span 80:Tween 20). The most stable carotenoid microemulsion was a microemulsion with 100 ppm of carotenoid added. The carotenoid microemulsion was able to inhibit photooxidation at 4000 lux for 4 hrs. The vitamin C beverage model added with 6 ppm carotenoid microemulsion was able to inhibit photooxidation compared to the control and 12 ppm, for up to 6 hrs and there was a significant decrease in vitamin C and antioxidants after 24 hrs of photooxidation. A. platensis carotenoid microemulsion with a concentration of 6 ppm could inhibit photooxidation on vitamin C beverages for up to 6 hrs.

Flavonoids and Derived Anthocyanin Pigments in Plants-Structure, Distribution, Function, and Methods for Quantification and Characterization.

Flavonoids represent a large class of phenolic specialized metabolites and play crucial roles in plant-environment interactions, including responses to biotic and abiotic factors. While the core flavonoid biosynthesis pathway is well known in several plant species, enzymes involved in modifying core flavonoid structures, furnishing them with distinct biological activities, continue to be identified. Anthocyanins, a specific type of flavonoid pigment, serve various functions, including attracting pollinators and seed-dispersing organisms when accumulated in flowers and seeds. Anthocyanins also accumulate in vegetative tissues of many plants, especially under unfavorable conditions. In this review, we present an overview of the diverse structures, various distributions, and multiple functions of flavonoids in plants.

Fabrication and characterization of blue nano ceramic-inks: Utilization of cobalt aluminate pigments prepared by solid state method

The current study focuses on the development and fabrication of ceramic nano inks with improved properties. Firstly, two types of pigments were prepared through a solid state process using fine gibbsite (Al(OH)3) or aluminum chloride (AlCl3) with cobalt chloride hexahydrate (CoCl2.6H2O). The stoichiometric precursors were well-mixed and fired at 1000oC; then milled by a high energy ball mill to obtain nano pigments. The prepared pigments were investigated for their phase composition and crystallite size by X-ray diffraction, and further confirmed by Fourier Transform Infrared (FTIR). The morphology and particle size were examined using a scanning electron microscope. The optical properties in terms of UV–Vis, photoluminence emission spectra and CIE chromaticity diagram were also tested. The chemical-state of cobalt and surface elemental composition of prepared Co-aluminate pigments were tested by X-ray photoelectron spectroscopy (XPS). Four groups of ceramic-inks (twelve formulations) were prepared using different percentages of cobalt aluminate pigments and additives. The fabricated inks were investigated for their morphology, rheology, contact-angle and sedimentation behavior. The results revealed that two cobalt aluminate pigments with spinel structure, nano sized particles and blue color, were successfully prepared by the proposed method. The results of optical properties indicated that the cobalt ions are located mainly in tetrahedral sites with a small amount in octahedral sites. The prepared pigments were successfully used in the fabrication of ceramic nano inks with improved properties. The viscosity of most fabricated inks was in the range needed for the industry (4–40 mPa s).

Optimizing Encapsulation of Active Compounds of Carrot By-Product in TPP-Chitosomes.

Liposomes coated with chitosan by ionic gelation with tripolyphosphate (TPP-chitosomes) are interesting particles for stabilizing active compounds. However, the encapsulation condition must be optimized. The aim of this study was to optimize the encapsulation of phenolics and carotenoids of carrot pomace in TPP-chitosomes by using a Central Composite Design 23 and response surface methodology. The independent variables were the phospholipid (0.8-4.2 mg/mL), chitosan (2.6-9.4 mg/mL), and carrot pomace (4-14 g/100 mL of ethanol) concentrations; the responses were the encapsulation efficiency in TPP-chitosomes (EE) of phenolics, a-carotene, and b-carotene and the particle size and zeta potential of the particles. The zeta potential ranged from +17 to +37 mV, indicating that the liposomes were coated with chitosan and that the particle sizes were in the nanometric to submicrometric scale. The optimized condition for encapsulating carotenoids was 2.5 mg/mL phospholipids, 6.0 mg/mL chitosan, and 12 g of carrot pomace/100 mL of ethanol. In this condition, the EE of phenolics and α- and β-carotene was 95%, 98%, and 99%, respectively. Therefore, TPP-chitosomes containing encapsulated phenolics and carotenoids, which can be obtained from agro-industrial by-products, have potential application as natural pigments in food or cosmetics. TPP-chitosomes can also be used to encapsulate other types of natural pigments.

Atacamite discolouration under the influence of arsenates in wall paintings in the Kizil Grottoes, Xinjiang, China

This study was focused on a specific blue‒green pigment applied on the edges of the green blocks of wall paintings in the Kizil Grottoes, the earliest Buddhist cave complex in China containing many wall paintings. Based on in situ portable XRF analyses, μ-Raman spectroscope, elemental analysis (SEM–EDS and EPMA-WDS) and μ-XRPD analyses, the pigment was proven to be lavendulan [NaCaCu5(AsO4)4Cl·5H2O], which has not been reported in ancient wall painting studies before. Lavendulan was found to coexist with atacamite [Cu2(OH)3Cl] in some of the samples in the study and showed a nanoneedle-like morphology. Further investigations of lavendulan revealed that it was probably not originally used as a pigment but was generated by the transformation of atacamite under the influence of arsenates [As(V)] and Na+. This phenomenon and the related mechanism were discovered in this study and are discussed in this paper. As an important cultural heritage site in the Silk Road, the Route Network of the Chang’an-Tianshan Corridor and the Kizil Grottoes are listed as UNESCO World and Natural Heritage sites. The pigment types and preservation conditions of wall paintings are similar to those of many wall paintings found along the Silk Road, and further attention should be given to this discolouration mechanism for heritage site conservation.

Exploring the viability of combined laser-induced breakdown spectroscopy and Raman spectroscopy for stratigraphic analysis of murals containing isomeric pigments: a case study on realgar and orpiment

A novel combined measurements techniques has been designed in this work, enabling the acquisition of laser-induced breakdown spectroscopy (LIBS) and Raman spectral signals at the same point on a sample. The application of this combined technique to the analysis of multi-layered mock-up blocks painted with orpiment and realgar pigments has yielded significant insights. By correlating variations in the emission line intensity of characteristic elements within the LIBS spectra with depth-specific Raman spectra, the number of laser pulses that penetrated the pigment layers has been accurately determined, thereby establishing a method to measure layer thickness. Finally, the technique wasto analysis the actual mural fragment from Mogao Cave 196, determining the types of pigment and the thickness of the pigment layers.Graphical

Natural Pigments Recovery from Food By-Products: Health Benefits towards the Food Industry.

Given the health risks associated with synthetic colorants, natural pigments have emerged as a promising alternative. These renewable choices not only provide health benefits but also offer valuable technical and sensory properties to food systems. The effective application of natural colorants, however, requires the optimization of processing conditions, exploration of new sources, and development of novel formulations to ensure stability and maintain their inherent qualities. Several natural pigment sources have been explored to achieve the broad color range desired by consumers. The purpose of this review is to explore the current advances in the obtention and utilization of natural pigments derived from by-products, which possess health-enhancing properties and are extracted through environmentally friendly methods. Moreover, this review provides new insights into the extraction processes, applications, and bioactivities of different types of pigments.

Preliminary investigation of potential links between pigmentation variants and opioid analgesic effectiveness in horses during cerebrospinal fluid centesis

BackgroundThe pleiotropic effects of the melanocortin system show promise in overcoming limitations associated with large variations in opioid analgesic effectiveness observed in equine practice. Of particular interest is variation in the melanocortin-1-receptor (MC1R) gene, which dictates pigment type expression through its epistatic interaction with the agouti signalling protein (ASIP) gene. MC1R has previously been implicated in opioid efficacy in other species; however, this relationship is yet to be explored in horses. In this study, analgesic effectiveness was scored (1-3) based on noted response to dura penetration during the performance of cerebrospinal fluid centisis after sedation and tested for association with known genetic regions responsible for pigmentation variation in horses.ResultsThe chestnut phenotype was statistically significant (P < 0.05) in lowering analgesic effectiveness when compared to the bay base coat colour. The 11bp indel in ASIP known to cause the black base coat colour was not significant (P>0.05); however, six single nucleotide polymorphisms (SNPs) within the genomic region encoding the ASIP gene and one within MC1R were identified as being nominally significant (P<0.05) in association with opioid analgesic effectiveness. This included the location of the known e MC1R variant resulting in the chestnut coat colour.ConclusionsThe current study provides promising evidence for important links between pigmentation genes and opioid effectiveness in horses. The application of an easily identifiable phenotype indicating variable sensitivity presents a promising opportunity for accessible precision medicine in the use of analgesics and warrants further investigation.