Search Results (768)

Dermal papilla (DP) cells orchestrate hair follicle growth and cycling by secreting signaling molecules that stimulate follicular epithelial stem cells. The signal peptide CUB-EGF-like domain-containing protein 3 (SCUBE3) was recently identified as a potent anagen stimulator secreted by DP cells. Ageratum houstonianum ethanolic extract (AHE) and its active constituent agerarin exhibit anti-inflammatory properties; however, their effects on hair follicle growth remain unclear. This study aimed to investigate the effects of AHE and agerarin on SCUBE3 expression in primary human DP cells and to elucidate the underlying molecular signaling pathway. Cell viability was assessed by measuring cell confluency. Ex vivo hair growth was analyzed using organ cultures of human hair follicles. Gene and protein expression were determined using reverse transcription-PCR, immunoblot analysis, immunofluorescent staining, tyramide signal amplification-based multiplex immunohistochemistry, and gene promoter-reporter assay in primary human follicle DP cells. In a hair follicle organ culture model, both AHE and agerarin increased the population of the anagen phase and promoted hair shaft elongation. AHE and agerarin significantly upregulated SCUBE3 expression at both the mRNA and protein levels. Mechanistically, AHE and agerarin induced activator protein-1 (AP-1) expression by activating mitogen-activated protein kinase signaling pathways, thereby increasing SCUBE3 gene promoter activity. AHE and agerarin promoted hair follicle growth by upregulating SCUBE3 expression via activation of the MAPK–AP-1 signaling axis. In conclusion, AHE and agerarin may serve as potential therapeutic agents for the prevention and treatment of alopecia (hair loss). Full article

Scalp microbes are recognized as contributors to hair loss by influencing scalp homeostasis and hair growth. However, the in vitro anti-hair loss activity of microbial culture media derived from healthy scalps remains unclear. In this study, resident microbes from 20 Korean participants with healthy scalps and hair were isolated, and Staphylococcus capitis was used to produce S. capitis ferment filtrate (SCFF). SCFF anti-hair loss activity was evaluated in human follicle dermal papilla cells (HFDPCs) and human adult low-Calcium High-Temperature (HaCaT) keratinocytes via proliferation assays, qPCR, immunocytochemistry, and SA-β-gal staining at 250–1000 μg/mL. SCFF increased cell density after 48 h in a concentration-dependent manner. In HFDPCs, SCFF controlled growth (KGF, IGF-1, and HGF) and androgen (AR and TGF-β2) factors, regulating key mRNAs for hair growth. SCFF mitigated scalp and hair aging by promoting sirtuins 1 and 7 and collagen type 13, while suppressing p21 and X-Gal staining. In HaCaT cells, SCFF exhibited a scalp barrier-strengthening effect by significantly increasing filaggrin and involucrin levels. It suppressed reactive oxidative stress and exhibited DPPH and ABTS radical scavenging activity. These results suggest that SCFF may modulate key pathways associated with hair loss by promoting scalp and hair anti-aging, barrier strengthening, enhancing antioxidant activity, and supporting hair growth. Full article

Heavy metals including mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) remain significant global toxins due to their environmental persistence, widespread anthropogenic release, and serious biological effects. This review consolidates current understanding of their natural and industrial sources, environmental cycling, human exposure routes, and population-level vulnerabilities. It covers their toxicokinetics and toxicodynamics, emphasizing species-specific absorption, distribution, and injury mechanisms, including oxidative stress, thiol binding, mitochondrial dysfunction, endocrine disruption, and cancer risk. Clinical signs range from subtle neurocognitive impairment and kidney damage to severe acute poisoning. The review evaluates evidence-based approaches to risk assessment and biomonitoring, such as blood, urine, hair, and speciation tests, noting issues, including unvalidated provoked testing. Treatment focuses on removing exposure, providing nutritional support, and offering supportive care, with chelation therapy reserved for specific cases. It explains the chemistry, pharmacology, and roles of chelating agents—ALA, DMSA, DMPS, Cys, GSH, and physiologic thiols, comparing their effectiveness, limitations, and costs for various metals. Emerging therapies, precision toxicology, and public health strategies are discussed within a prevention-focused context. Unlike prior reviews focused primarily on toxic mechanisms or isolated clinical management, this review integrates mechanistic toxicology, biomarker interpretation and speciation, evidence-based clinical care, and ethical, cost-conscious decision-making within a single translational framework. This narrative review synthesizes foundational and contemporary literature published through 2025, with particular emphasis on studies published since 2000 that inform toxicokinetics, biomarker interpretation, diagnostics, clinical management, and prevention. Full article

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products. Full article

Background: The cochlea is a specialized sensory organ essential for hearing. To elucidate its cellular and molecular architecture and prioritize candidate genes associated with hearing loss (HL), we constructed a cross-species single-cell transcriptomic atlas of human fetal and postnatal mouse cochleae. Methods: We integrated single-cell and single-nucleus RNA sequencing datasets from human fetal cochleae and postnatal mouse cochleae to build a comprehensive cross-species single-cell transcriptomic atlas. Cell-type annotation, transcriptional regulator analysis, intercellular communication, and disease phenotypes were performed to dissect the cochlear cellular landscape, regulatory programs, and potential HL gene candidates. Results: A total of 19 major cochlear cell types were identified in both species, with conserved cellular composition and transcriptional programs. Comparative analysis revealed strong transcriptional conservation between matched human and mouse cell types, particularly in supporting, schwann cells and hair cells. Cell–cell communication analysis revealed conserved signaling pathways, including the BDNF-NTRK2 axis, potentially involved in cochlear development and auditory function. Regulatory network inference uncovered conserved and previously undercharacterized transcription factors, such as SKOR1, RFX2, and PAX2, predicted to be associated with hair cell identity and function. We further defined a conserved gene module of 3138 hair cell-enriched genes, from which 24 candidate HL-associated genes (e.g., ATP8B1, BDNF, and SOD1) were prioritized through integration with human disease databases and mouse auditory phenotype annotations. Conclusions: This study provides a high-resolution cross-species cochlear atlas, revealing conserved molecular programs and candidate HL-associated genes, offering valuable insights into auditory biology and potential avenues for further investigation. Full article

Hair serves essential functions, including mechanical sensing, head protection, and body temperature regulation, while also playing a significant role in human aesthetics. However, factors such as hormonal imbalances, autoimmune disorders, infections, and psychological stress contribute to the widespread issue of hair loss, particularly among the elderly, adversely affecting self-confidence and self-esteem. Although treatments such as minoxidil, finasteride, and dutasteride have received regulatory approval, their associated side effects, such as sexual dysfunction, neuropsychiatric issues, and cardiovascular symptoms, can impede patient recovery. While follicular unit transplantation and stem cell therapy show promising outcomes, they are not suitable for all types of hair disorders. Short peptides that mimic intracellular signals and exhibit diverse biological effects have emerged as a promising approach for stimulating hair regrowth. By combining different formulations and nanosystems, the limitations of short peptides can be effectively addressed. This review systematically summarizes recent advances in peptide-based treatments for hair loss, highlighting their advantages and limitations. Full article

Human hair performs a number of important physiological and esthetic functions. Hair loss and alopecia are complex disorders which affect people all over the world. Hair loss can be an early manifestation of various autoimmunological disorders. Despite a growing interest of researchers in the role of immune factors—especially autoantibodies—in the etiology of certain types of alopecia, their role in alopecia remains uncertain. Several potential autoantigens of follicular components, mainly derived from keratinocytes and melanocytes of the hair follicles, have been found to play a role in the development of alopecia areata. The list of autoantigens includes trichohyalin, keratin 16, fibroblast growth factor receptor 3, glycoprotein-100, melanoma-associated antigen recognized by T cells 1, dopachrome tautomerase/tyrosinase-related protein 2, tyrosinase, and tyrosine hydroxylase. This narrative review presents different aspects of immunopathogenesis of alopecia, from physiology (hair follicle immune privilege) to pathology (disruption of hair follicle immune privilege) and signaling pathways. Identification of key autoantigens could potentially pave the way for the development of new, effective, and more targeted immunotherapies for alopecia. Full article

Extracellular vesicles (EVs) derived from microbial sources, including beer yeast (Saccharomyces cerevisiae), have recently attracted increasing attention as bioactive nanostructures with potential biomedical and cosmetic applications. In this study, EVs were isolated from Saccharomyces cerevisiae (beer yeast) using an electrokinetic ion-binding filtration system, followed by tangential flow filtration (TFF)-based buffer exchange. Their physicochemical characteristics and hair follicle-related biological activities were systematically evaluated. Nanoparticle tracking analysis demonstrated a mean particle size within the typical EV range, and zeta potential analysis confirmed a negatively charged surface. Cryo-transmission electron microscopy further verified the presence of lipid bilayer-enclosed nanovesicles. Biological activity was assessed in human dermal papilla cells, keratinocytes, and dermal fibroblasts, which collectively represent key components of the hair follicle microenvironment. At non-cytotoxic concentrations, yeast-derived EVs enhanced dermal papilla cell proliferation and promoted keratinocyte migration. The EVs attenuated pro-inflammatory cytokine expression under stimulated conditions and upregulated collagen-related gene expression in dermal fibroblasts. In addition, measurable antioxidant activity was observed. Collectively, these findings indicate that S. cerevisiae-derived extracellular vesicles exhibit multifunctional bioactivity relevant to the regulation of hair follicle-associated cellular processes. This study supports the potential of microbial EVs as scalable bioactive platforms for modulating hair follicle microenvironmental homeostasis. Full article

Healthy and asymptomatic cats may serve as reservoirs of fungal pathogens, facilitating transmission through direct contact or environmental contamination, and they may represent an underrecognized source of subclinical fungal infection in humans, particularly among cat owners and veterinarians. We evaluated the prevalence of fungal species in healthy cats and their owners, assessed potential cat–human transmission, identified feline lifestyle factors associated with Microsporum canis carriage, and evaluated antifungal susceptibility of the most prevalent isolated fungi. We collected 59 cat facial hair and 59 owner nail samples for fungal isolation and identification. Five fungal species were identified, M. canis, Aspergillus flavus, A. niger, A. fumigatus, and A. terreus, which were found in both cats and humans. Aspergillus spp. were the most frequently detected fungi in both groups. Significant associations between cats and owners were observed for M. canis (p = 0.010) and A. niger (p = 0.050). Long-haired cats showed a significantly higher prevalence of carrying M. canis (p = 0.024), while other lifestyle factors were not associated with fungal carriage. The antifungal susceptibility profiles of the tested fungi were broadly similar between feline and human isolates; however, resistance to itraconazole and amphotericin B was detected among Aspergillus spp. Healthy cats and their owners frequently share fungal species, especially M. canis, which suggests possible household zoonotic transmission. Long-haired cats are at higher risk of M. canis carriage. Full article

Demodex mites are common commensals of mammalian skin, but under certain conditions, they can cause severe skin diseases. This study analyzed the presence, diversity, and phylogenetic relationships of Demodex species in two wolf subspecies from southern Europe to determine whether species-level differences exist between wild and domestic canids after thousands of years of divergence. A total of 1400 hair samples from 140 wolves were analyzed using a real-time PCR (qPCR) targeting mitochondrial 16S rRNA and nuclear 18S rRNA genes. Overall, 37.1% (52/140; 95% CI: 29.0–45.9%) of wolves were positive for Demodex DNA, with a higher prevalence in Italian (46%) than in Iberian (36%) wolves. The lip and chin areas were the most reliable sampling sites. Four Demodex species were identified in wolves: D. injai and D. canis (associated with dogs), and D. folliculorum and D. brevis (associated with humans). Co-infestations involving multiple Demodex species were recorded for the first time in wild canids. These results challenge the long-held belief of strict host specificity in Demodex mites. The discovery of Demodex species associated with both humans and dogs in wolves supports the idea that host-switching and ecological interactions have occurred throughout the evolution of canids and humans. Such cross-species transfers may have taken place during the early domestication of dogs, representing a plausible scenario compatible with our data. However, given the isolated history of the two southern wolf populations, it is more probable that these findings result from recent interspecific transmission events, likely facilitated by ecological overlap with domestic animals and human environments. Future genomic studies will be essential for clarifying the evolutionary relationships within the genus Demodex and its host associations. Full article

Hair loss affects over half of adults by age 70 and represents a major determinant of overall hair health, imposing significant psychosocial burden across genders. Nutritional factors play a critical role in follicle biology, yet targeted strategies remain underexplored. This comprehensive review examines five key hair-constituent macromolecules—type I collagen, elastin, keratin, ceramides, and melanin—and their physiological and clinical impacts on hair structure, density, shining, and growth. We conducted a structured literature search in PubMed and Google Scholar through January 2025, selecting in vitro studies, animal experiments, and human clinical trials that evaluated each macromolecule’s effects on follicular function and hair fiber integrity. Type I collagen enhances dermal papilla cell proliferation, upregulates Wnt/β-catenin and growth factors, and improves hair thickness and breakage resistance in randomized controlled trials. Keratin hydrolysates replenish cortical protein, reinforce disulfide cross-links, and reduce telogen shedding, with clinical studies demonstrating 30–50% decreases in hair loss and gains in tensile strength. Oral ceramide formulations restore the cuticular lipid barrier, shift follicles toward anagen, and increase hair density in double-blind trials. Although direct clinical data on melanin supplementation are lacking, ex vivo and animal models confirm its role as a UV-protective pigment, preserving keratin integrity and color fastness. Together, these macromolecules constitute a coherent framework for hair health, and clinical studies increasingly provide evidence that their combined or parallel application can meaningfully enhance hair density, strength, shine, and resilience. Full article

Background/Objectives: The increasing global trend in nail beautification may lead to analyses of nails with semi-permanent polish for the identification of degraded human remains. This study aimed to evaluate the effects of cosmetic nail treatment on forensic STR DNA profiling and phenotyping of eye, hair, and skin colour characteristics using a massively parallel sequencing (MPS) assay. Methods: Forty-two nail samples obtained from 21 volunteers, classified in “new”, occasional and regular semi-permanent polish users, were submitted to DNA analysis. Results: The use of semi-permanent nail polish, particularly when applied repeatedly, resulted in a significant reduction in DNA recovery, but it did not affect STR typing for personal identification. Mixed STR profiles were observed in 28.6% of the samples, indicating that the nail washing procedure employed before DNA extraction did not completely remove the foreign DNA; however, this could be useful depending on the forensic context. FDP analysis was successfully applied on nails with semi-permanent polish that showed a good quantity of DNA and single-source profiles. Conclusions: The results highlight the evidentiary value of fingernails even if treated with semi-permanent nail polish that should still be regarded as a source of DNA for personal identification and further investigation in the forensic context. Full article

Human skin and hair act as multifunctional barriers but are highly sensitive to environmental pollutants originating from air, water, and cosmetic products. Epidemiological studies report that exposure to particulate matter (PM_2.5–PM₁₀), nitrogen oxides (NO_x), and volatile organic compounds increases the risk of skin and hair disorders. For instance, women in high-traffic areas (N = 211) show significantly more pigment spots and nasolabial wrinkles compared to those in rural areas (N = 189), indicating accelerated skin ageing. Children aged 9–11 exposed to PM₁₀, benzene, and NO_x exhibit increased incidence of atopic dermatitis. Systemic exposure to dioxins causes chloracne, while co-exposure to polycyclic aromatic hydrocarbons (PAHs) and UVA radiation elevates skin cancer risk. Psoriasis flares are associated with mean pollutant concentrations over the 60 days preceding flare events in 957 patients, and hyperpigmentation prevalence increases in populations exposed to traffic-related PM and ROS-inducing pollutants. Hair loss is linked to oxidative stress from PM and PAHs absorbed on hair fibers, with in vitro studies showing keratinocyte apoptosis in scalp hair follicles. This review evaluates natural adsorbents such as zeolites, clays, activated carbon, and polyphenol-rich plant extracts for anti-pollution cosmetic formulations. Adsorption capacities range from 60 to 150 mg·g⁻¹ depending on the pollutant, with removal efficiencies of 30–55% in model topical systems. Mechanisms include ion exchange, surface adsorption, hydrophobic interactions, and radical scavenging. Incorporating 2–5% w/w of these adsorbents in cosmetic formulations significantly reduces pollutant deposition on skin and hair. These findings support the development of evidence-based, sustainable anti-pollution cosmetic strategies that quantitatively mitigate environmental stressor effects. Full article

Human hair waste represents a dense nitrogen reservoir (~15% N); however, its agricultural valorization is hindered by two concurrent barriers: the extreme recalcitrance of alpha-keratin and the high salinity derived from cosmetic treatments. While chemical hydrolysis generates secondary pollutants, biological composting often fails due to osmotic inhibition of non-adapted inoculants. Here, we report a biological strategy to circumvent this osmotic bottleneck using unwashed human hair collected from professional salons. We compared the degradation efficiency of a syntrophic Effective Microorganisms (EM) consortium with traditional single-strain inoculants (Trichoderma spp. and Bacillus spp.) in a 16-week co-composting system. Data revealed that the EM consortium displayed superior resilience, sustaining thermophilic sanitation (>45 °C) compliant with US EPA PFRP standards and achieving a Nitrogen Mineralization Rate of 883 mg N kg⁻¹ week⁻¹ (nearly triple the control), resulting in a final N content of 1.41% (14,133 mg kg⁻¹). Crucially, the EM treatment reduced electrical conductivity from a phytotoxic 7.23 mS cm⁻¹ to a tolerable level of 3.82 mS cm⁻¹, a mitigation effect likely mediated by humification-driven ion chelation. This performance suggests a “syntrophic succession” mechanism where initial acidification facilitates subsequent proteolytic attack. The final product presented a high sulfur-to-nitrogen ratio indicative of extensive disulfide bond cleavage. Preliminary economic estimates (~$60 USD ton⁻¹) confirm the process’s viability for decentralized scalability, though future molecular validation is recommended. We conclude that bio-augmentation with metabolically diverse consortia is essential to process chemically treated hair waste, converting a hazardous salon residue into a high-value proteinaceous biofertilizer. Full article

Current wound healing strategies must confront numerous challenges. Helminth-induced immunomodulation offers a promising therapeutic avenue for inflammatory diseases and injury repair. However, research on the role of helminths in damage recovery remains limited. We utilized glycogen—a naturally occurring biomaterial—to encapsulate SJMHE1, a bioactive peptide derived from Schistosoma japonicum, and successfully developed a facilely prepared hydrogel formulation denoted as SJMHE1-gel. The properties of SJMHE1-gel, its effect on cell activity, and its performance in a murine full-thickness skin defect model were evaluated. The glycogen-based hydrogel exhibited a uniform pore size, excellent biocompatibility, and sustained release of SJMHE1. Topical application of SJMHE1-gel enhanced collagen deposition, promoted angiogenesis, facilitated the regeneration of hair follicles and sebaceous glands, and accelerated full-thickness wound healing. SJMHE1-gel also promoted M2 macrophage polarisation and suppressed inflammatory cytokine expression both in vivo and in vitro. Mechanistically, SJMHE1-treated macrophages upregulate TGF-β, which in turn promotes the migration of L929 fibroblasts and human umbilical vein endothelial cells (HUVECs) via the Smad3 pathway. Neutralization of TGF-β attenuates phosphorylated Smad3 (p-Smad3) levels and impairs the migratory capacity of both fibroblasts and HUVECs. Additionally, SJMHE1-treated macrophages upregulate VEGFA, thereby enhancing angiogenic tube formation in HUVECs. This easy-to-prepare hydrogel can regulate macrophage polarization, inhibit inflammation, promote angiogenesis, and accelerate collagen deposition, acting across wound healing stages to provide a novel therapeutic strategy. Full article