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Grey hair, a common ageing‐associated phenomenon in humans, is mainly attributed to the damage of melanocytes and the absence of melanin. Grey hair has long been treated with traditional medicine, and new research has shown that various plant‐derived monomers can increase tyrosinase activity and melanogenesis, indicating that they may have therapeutic value in curing grey hair. In this study, we outlined the role of melanin and pigmentation during hair growth and collected various medicinal plant monomers with the potential value of grey hair reversal. Many active ingredients from medicinal plants, such as fraxinol, tribuloside, morin and naringenin, can upregulate melanogenesis and tyrosinase activity through different signalling pathways. Some of them can promote melanosome quantity, maturation and transportation as well. Monomers isolated from medicinal plants may act as stimulators of melanogenesis. Many plant‐derived monomers perform as activators that upregulate melanin synthesis and tyrosinase activity through different signalling pathways. They are of great research value for the treatment of hair greying. Moreover, to further improve experimental effect, safety and reliability, a systematic and comprehensive evaluation system needs to be established in the future before studying their clinical efficacy.

Empirical and anecdotal evidence has associated stress with accelerated hair greying (formation of unpigmented hairs) 1 , 2 , but so far there has been little scientific validation of this link. Here we report that, in mice, acute stress leads to hair greying through the fast depletion of melanocyte stem cells. Using a combination of adrenalectomy, denervation, chemogenetics 3 , 4 , cell ablation and knockout of the adrenergic receptor specifically in melanocyte stem cells, we find that the stress-induced loss of melanocyte stem cells is independent of immune attack or adrenal stress hormones. Instead, hair greying results from activation of the sympathetic nerves that innervate the melanocyte stem-cell niche. Under conditions of stress, the activation of these sympathetic nerves leads to burst release of the neurotransmitter noradrenaline (also known as norepinephrine). This causes quiescent melanocyte stem cells to proliferate rapidly, and is followed by their differentiation, migration and permanent depletion from the niche. Transient suppression of the proliferation of melanocyte stem cells prevents stress-induced hair greying. Our study demonstrates that neuronal activity that is induced by acute stress can drive a rapid and permanent loss of somatic stem cells, and illustrates an example in which the maintenance of somatic stem cells is directly influenced by the overall physiological state of the organism. Stress induces hair greying in mice through depletion of melanocyte stem cells, which is mediated by the activation of sympathetic nerves rather than through immune attack or adrenal stress hormones.

Greying of the hair is an obvious sign of human aging. In addition to age, sex- and ancestry-specific patterns of hair greying are also observed and the progression of greying may be affected by environmental factors. However, little is known about the genetic control of this process. This study aimed to assess the potential of genetic data to predict hair greying in a population of nearly 1000 individuals from Poland. The study involved whole-exome sequencing followed by targeted analysis of 378 exome-wide and literature-based selected SNPs. For the selection of predictors, the minimum redundancy maximum relevance (mRMRe) method was used, and then two prediction models were developed. The models included age, sex and 13 unique SNPs. Two SNPs of the highest mRMRe score included whole-exome identified KIF1A rs59733750 and previously linked with hair loss FGF5 rs7680591. The model for greying vs. no greying prediction achieved accuracy of cross-validated AUC = 0.873. In the 3-grade classification cross-validated AUC equalled 0.864 for no greying, 0.791 for mild greying and 0.875 for severe greying. Although these values present fairly accurate prediction, most of the prediction information was brought by age alone. Genetic variants explained < 10% of hair greying variation and the impact of particular SNPs on prediction accuracy was found to be small. The rate of changes in human progressive traits shows inter-individual variation, therefore they are perceived as biomarkers of the biological age of the organism. The knowledge on the mechanisms underlying phenotypic aging can be of special interest to the medicine, cosmetics industry and forensics. Our study improves the knowledge on the genetics underlying hair greying processes, presents prototype models for prediction and proves hair greying being genetically a very complex trait. Finally, we propose a four-step approach based on genetic and epigenetic data analysis allowing for i) sex determination; ii) genetic ancestry inference; iii) greying-associated SNPs assignment and iv) epigenetic age estimation, all needed for a final prediction of greying.

The process of hair pigmentation is intricate and involves different subpopulations of melanocytes within the hair follicle. The pigmentation of hair is intricately connected to the hair cycle, with melanocytes being active during specific stages and experiencing apoptosis during others. The pathophysiology of hair pigment dilution involves a progressive decrease in melanocytes, resulting in the greying of hair. Genetics contribute to irregularities in hair pigmentation, with multiple genes influencing melanin production and the melanocyte development. Silvery hair syndromes are hereditary conditions characterized by hypopigmentation, which leads to a decrease or absence of pigmentation in the skin, hair, and eyes. These conditions may arise from mutations that affect the growth and function of melanocytes. The typical syndromes characterized by silvery-grey hair include Griscelli-Pruniéras syndrome, Chédiak-Higashi syndrome, Elejalde syndrome, and oculocerebral hypoplasia syndrome. These disorders are characterized by significant lightening of the skin and hair color, and it is important to identify and treat them early in order to prevent consequences that affect the entire body. The process of hair coloring is intricate and is regulated by hereditary factors and the hair growth cycle. Silvery hair syndromes are genetic conditions characterized by reduced pigmentation in the skin and hair, resulting in a widespread lightening of color. Timely identification and treatment of these illnesses are essential to address any related systemic consequences.

Type 2 diabetes is usually accompanied by premature grey hair. In this study, we analysed differences in the lipid composition of black and white hair follicles between women with type 2 diabetes and healthy populations, using lipidomic methods. We examined the correlation between the lipid composition of female grey hair follicles and type 2 diabetes mellitus, and we screened for potential grey-hair-delaying ingredients using network pharmacology. Forty-one female volunteers with type 2 diabetes (diabetes, D) and thirty-five healthy volunteers (healthy, H) aged 55–65 years were recruited. Hair roots, including the follicular portion, were collected from grey hair (D-W for diabetic volunteers and H-W for healthy volunteers) and black hair (D-B for diabetic volunteers and H-B for healthy volunteer). Lipids were extracted separately and analysed using UPLC-QTOF-MS (Ultra-Performance Liquid Chromatography–Tandem Time-of-Flight Mass Spectrometry), combined with an OPLS-DA (Orthogonal Partial Least Squares Discriminant Analysis) model to identify different lipids among different groups under VIP conditions (VIP > 1, p < 0.05, and fold change ≥ 2). Further screening was performed using the ROC (receiver operating characteristic) curve method, selecting lipids with an AUC (area under the curve) value greater than 0.8 and specificity plus sensitivity greater than 1.6. Finally, bioinformatics and reverse network pharmacology were used to screen relevant targets, ingredients, and herbs to find suitable raw materials with anti-grey-hair effects. We found the following: (1) Ten significant differential lipids were identified under VIP conditions in the D-W and D-B groups, and five potential differential lipids (1-O-alpha-D-glucopyranosyl-1,2-eicosandiol, emmotin A, odyssic acid, PI-Cer(t18:0/26:0(2OH)), and NAPE(18:1(9Z)/16:1(9Z)/18:0)) were further screened using ROC analysis. The levels of all five lipids were significantly higher in D-W than in D-B, and these elevated levels may have been related to the production of grey hair in diabetic patients. (2) Thirteen significantly different lipids were screened under VIP conditions in the H-W and H-B groups, and five potential differential lipids were screened via ROC analysis (PS(O-16:0/13:0), PA(12:0/16:1(9Z)), PS(13:0/20:3(8Z,11Z,14Z)), GlcCer(d18:1/24:1(15Z)), and PS(O-20:0/17:2(9Z,12Z))). The levels of all five lipids were significantly higher in H-B than in H-W, and we hypothesised that their reduced levels were associated with the production of grey hair in the healthy population. (3) Twelve significantly different lipids were screened under VIP conditions in the D-W and H-W groups, and two potential differential lipids were screened via ROC analysis (fucoxanthinol 3-heptadecanoate 3′-myristate and 2-(3-hydroxyphytanyl)-3-phytanyl-sn-glycerol). The contents of both lipids were significantly higher in H-W than in D-W, and there were differences in the lipid composition of grey hair in the D and H populations. (4) Important ingredients with possible therapeutic effects were obtained through lipid-matched target screening: resveratrol, calycosin, epigallocatechin 3-gallate, and herbs such as the fruit of the glossy privet, etc. In summary, the production of grey hair in the D and H populations may be affected by different lipids. The lipid components emmotin A and fucoxanthinol 3-heptadecanoate 3′-myristate were significantly higher in the D and H populations than in the same groups (D-B, H-B), and these are pregnenolone lipids (PRs). We hypothesised that PRs can influence the production of grey hair in both populations. The screening of important differential lipids may serve to provide diagnostic loci or therapeutic targets, while matching ingredients and herbs may provide a basis and direction for the subsequent development of anti-grey-hair ingredients.

The essential oils have been used for many purposes due to their diverse pharmacological properties and morphological properties. Since it aids in the scalp's efficient absorption of nutrients and stimulates dormant hair follicles, the active fraction has been isolated in this study to examine its potential as a hair growth promoter. Additionally, the phytoconstituent or phytoconstituents responsible for hair growth activity have been identified. The current study's objective is to determine the amount of ursolic acid and dienin in several herbal hair oils with varying formulations using the HPLC technique. The various herbs and oils utilised in this study were used to make herbal hair oil that included important chemical components such as diosgenin and ursolic acid. These elements are in charge of promoting hair development and minimising grey hair. Studies on morphology, chemistry, and pharmacology assessed the oil. By using HPLC method the prepared oils are estimated for Ursolic acid and Diosgenin and one of the formulations has shown with good result.

Hair dyes have been used to cover gray hair or to give an appealing look. In the present study, the extract of Calendula Officinalis was used in preparing a hair dye. This represents a natural gateway in development of hair dye to avoid damage caused by synthetic dyes. The yellow coloring principle of the extract, Calendulin, was converted into nano-sized formula ensuring hair fiber penetration. Nine formulae were prepared by solvent evaporation technique, based on a 32 factorial design using Design Expert® program, independent variables being: speed and time of homogenization; three levels: low, medium and high. Polyvinyl alcohol (0.5% w/v) was used as stabilizing agent. Formulae were evaluated by determination of Zeta size, potential and polydispersity index. Response surface modeling enabled choosing the optimal formula (least particle size, polydispersity index and highest zeta potential), which was evaluated by transmission electron microscopy and dyeing effect as a gel containing 0.5% Carboxymethyl cellulose. F7, produced by operating the homogenizer at 26000rpm for 10 minutes proved to be optimal which succeeded to dye white hair and lighten up the black hair as evidenced by optical microscope images. Hence it was recommended to use F7 in covering the white hair.

Background Greying of the hair is an obvious sign of human aging. In addition to age, sex- and ancestry-specific patterns of hair greying are also observed and the progression of greying may be affected by environmental factors. However, little is known about the genetic control of this process. This study aimed to assess the potential of genetic data to predict hair greying in a population of nearly 1000 individuals from Poland. Results The study involved whole-exome sequencing followed by targeted analysis of 378 exome-wide and literature-based selected SNPs. For the selection of predictors, the minimum redundancy maximum relevance (mRMRe) method was used, and then two prediction models were developed. The models included age, sex and 13 unique SNPs. Two SNPs of the highest mRMRe score included whole-exome identified KIF1A rs59733750 and previously linked with hair loss FGF5 rs7680591. The model for greying vs. no greying prediction achieved accuracy of cross-validated AUC = 0.873. In the 3-grade classification cross-validated AUC equalled 0.864 for no greying, 0.791 for mild greying and 0.875 for severe greying. Although these values present fairly accurate prediction, most of the prediction information was brought by age alone. Genetic variants explained < 10% of hair greying variation and the impact of particular SNPs on prediction accuracy was found to be small. Conclusions The rate of changes in human progressive traits shows inter-individual variation, therefore they are perceived as biomarkers of the biological age of the organism. The knowledge on the mechanisms underlying phenotypic aging can be of special interest to the medicine, cosmetics industry and forensics. Our study improves the knowledge on the genetics underlying hair greying processes, presents prototype models for prediction and proves hair greying being genetically a very complex trait. Finally, we propose a four-step approach based on genetic and epigenetic data analysis allowing for i) sex determination; ii) genetic ancestry inference; iii) greying-associated SNPs assignment and iv) epigenetic age estimation, all needed for a final prediction of greying.