Age-related hair changes in men: Mechanisms and management of alopecia and graying

Irradiation-induced hair graying in mice: an experimental model to evaluate the effectiveness of interventions targeting oxidative stress, DNA damage prevention, and cellular senescence

Hair graying, also known as canities or achromotrichia, is a natural phenomenon associated with aging and is influenced by external factors such as stress, environmental toxicants, and radiation exposure. Understanding the mechanisms underlying hair graying is an ideal approach for developing interventions to prevent or reverse age-related changes in regenerative tissues. Hair graying induced by ionizing radiation (γ-rays or X-rays) has emerged as a valuable experimental model to investigate the molecular pathways involved in this process. In this review, we examine the existing evidence on radiation-induced hair graying, with a particular focus on the potential role of radiation-induced cellular senescence. We explore the current understanding of hair graying in aging, delve into the underlying mechanisms, and highlight the unique advantages of using ionizing-irradiation-induced hair graying as a research model. By elucidating the molecular pathways involved, we aim to deepen our understanding of hair graying and potentially identify novel therapeutic targets to address this age-related phenotypic change.

Combatting ageing in dermal papilla cells and promoting hair follicle regeneration using exosomes from human hair follicle dermal sheath cup cells

Dermal papilla cells (DPCs) undergo premature ageing in androgenetic alopecia and senescent alopecia. As critical components of hair follicle reconstruction, DPCs are also prone to senescence in vitro, resulting in a diminished hair follicle inductivity capacity. Dermal sheath cup cells (DSCCs), a specific subset of hair follicle mesenchymal stem cells, intimately linked to the function of DPCs. The primary objective of this research is to investigate the anti-ageing effect of exosomes derived from DSCCs (ExoDSCCs ) on DPCs. Exosomes were utilized to treat H2 O2 -induced DPCs or long-generation DPCs(P10). Our findings demonstrate that ExoDSCCs(P3) promote the proliferation, viability and migration of senescent DPCs while inhibiting cell apoptosis. The expression of senescence marker SA-β-Gal were significantly downregulated in senescent DPCs. When treated with ExoDSCCs(P3) , expression of inducibility related markers alkaline phosphatase and Versican were significantly upregulated. Additionally, ExoDSCCs(P3) activated the Wnt/β-catenin signalling in vitro. In patch assay, ExoDSCCs(P3) significantly promoted hair follicle reconstruction in senescent DPCs. In summary, our work highlights that ExoDSCCs(P3) may restore the biological functions and improve the hair follicle induction ability of senescent DPCs. Therefore, ExoDSCCs(P3) may represent a new strategy for intervening in the ageing process of DPCs, contributing to the prevention of senile alopecia.

Cell Therapy for Androgenetic Alopecia: Elixir or Trick?

Androgenetic alopecia is the most common cause of hair loss aggravated by increased life pressure, tension, and anxiety. Although androgenetic alopecia (AGA) does not significantly effect physical health, it can have serious negative impact on the mental health and quality of life of the patient. Currently, the effect of medical treatment for AGA is not idealistic, stem cell-based regenerative medicine has shown potential for hair regrowth and follicle repair, but the long-term effect and mechanism of stem cell therapy is not quite explicit. In this review, we summarize the methods, efficacy, mechanism, and clinical progress of stem cell therapies for AGA by now, hope it will present a more comprehensive view in this topic.

Investigating the morphology and genetics of scalp and facial hair characteristics for phenotype prediction

Microscopic traits and ultrastructure of hair such as cross-sectional shape, pigmentation, curvature, and internal structure help determine the level of variations between and across human populations. Apart from cosmetics and anthropological applications, such as determining species, somatic origin (body area), and biogeographic ancestry, the evidential value of hair has increased with rapid progression in the area of forensic DNA phenotyping (FDP). Individuals differ in the features of their scalp hair (greying, shape, colour, balding, thickness, and density) and facial hair (eyebrow thickness, monobrow, and beard thickness) features. Scalp and facial hair characteristics are genetically controlled and lead to visible inter-individual variations within and among populations of various ethnic origins. Hence, these characteristics can be exploited and made more inclusive in FDP, thereby leading to more comprehensive, accurate, and robust prediction models for forensic purposes. The present article focuses on understanding the genetics of scalp and facial hair characteristics with the goal to develop a more inclusive approach to better understand hair biology by integrating hair microscopy with genetics for genotype-phenotype correlation research.

Exploration of potential lipid biomarkers for age-induced hair graying by lipidomic analyses of hair shaft roots with follicular tissue attached

BACKGROUND

Age-induced hair graying (AIHG)is one of the visual hallmarks of aging, but its biological mechanism remains unclear. Changes in the hair-follicle lipid profiles associated with AIHG have not been defined.

OBJECTIVES

To define the differences in the hair follicle lipid profiles of female black and gray/white hair follicles.

METHODS

The lipid profile of hair follicles was determined by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Multivariate data analysis was used to determine changes in the lipid profiles in hair follicle roots.

RESULTS

We identified the different lipids in hair follicle roots between black hair (HB) and white hair (HW) and analyzed the key lipids that contribute to the development of HW. The results showed that the total lipid content of the HW was significantly reduced. There were significant differences in sphingolipid content, with HB higher than HW. Two subclasses, glucosylceramide (GlcCer) and galactosylceramide, were significantly different. GlcCer, phosphatidylserine, and phosphatidic acid levels were higher in the HB group. The sphingolipid metabolism involved in GlcCer(d18:1/24:1[15Z]) is a statistically significant lipid metabolic pathway.

CONCLUSION

Five major individual lipid candidates are involved in the production of AIHG. GlcCer shows a significant reduction in HW and is a potential target for further research into AIHG.

Hair Aging and Hair Disorders in Elderly Patients

Hair loss in elderly patients is a common complaint. It can be related to different conditions that affect patients' quality of life and represents a challenge for dermatologists. It affects both men and women during the aging process with an estimated percentage of balding after 65 years of age of 53% and 37%, respectively. Androgenetic alopecia, frontal fibrosing alopecia, senile alopecia, and erosive pustular dermatosis of the scalp are the hair diseases most frequently described in this age group. The objective of this review is to summarize the current knowledge about alopecia affecting elderly patients, differentiating between chronological hair aging signs and pathological changes, to help clinicians, offer an adequate management of these disorders to their patients.

Sex differences in clinical trials of ALRV5XR treatment of androgenetic alopecia and telogen effluvium

Introduction

ALRV5XR treatment of androgenetic alopecia (AGA) and telogen effluvium (TE) has early evidence of regenerating a normal scalp hair phenotype in both sexes.

Design

We performed two 24-week double-blinded placebo-controlled comparison trials, one in each sex, on the ALRV5XR treatment effect on hair regeneration, in AGA and TE, in 92 AGA subjects (24 also had TE). Forty-six women (age 24–64 years) and 46 men (age 22–63 years) were randomized 1:1 to either ALRV5XR or placebo regimens (one b.i.d. oral capsule and daily administration of shampoo, conditioner, and follicle serum).

Evaluation

Primary outcomes: Absolute and relative changes in terminal hair (TH) density. Secondary outcomes: Response rate, changes in vellus hair (VH) density, TH/VH ratio, hair diameter, growth, and shedding rate.

Results

Forty-one women (20 ALRV5XR, 21 placebo) and 36 men (17 ALRV5XR, 19 placebo) completed the trials. TH outcome was evaluable for 18 and 21 women and 11 and 11 men (ALRV5XR, placebo, respectively). Efficacy in women: 30.1 THs/cm2 (p = 0.0002) and 19.7% (p = 0.0016). Efficacy in men: 21.0 THs/cm2 (p = 0.0014) and 16.4% (p = 0.0012). 66.7% of women and 100% of men responded to ALRV5XR. TH/VH ratio for men increased 33.0% (p = 0.0033). Growth rate in women increased by 30.7 μm/24 h (p < 0.0001) and 10.0% (p < 0.0001). There were no adverse events reported.

Conclusion and relevance

ALRV5XR induced significant regrowth of TH. Accelerating regrowth by reactivation of dormant telogen follicles were the dominant effects in women. Thickening of miniaturized hair and regrowth of dormant telogen follicles contributed equally to the increased TH seen in men (see Graphical Abstract).

Androgenetic alopecia and COVID-19: A review of the hypothetical role of androgens

The coronavirus disease 2019 (COVID‐19) has become the most emerging health issue globally. A prompt investigation regarding disease management and treatment is crucial for decreasing the burden of the disease. Many explorations and hypotheses have been posed, but the definite treatment has not been determined for COVID‐19. Recent studies described a substantial prevalence of COVID‐19 and also a higher rate of morbidity and mortality in men afflicted with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. The gender‐related discordance in COVID‐19 infection may be due to hormonal differences, socioeconomic factors, genetic susceptibility, gender‐related comorbidities, and habits like alcohol consumption. On the other hand, several studies proposed that androgens could improve the immune system and have a protective role in COVID‐19, and decreased levels of androgens might be associated with unsatisfactory outcomes. In the field of dermatology, androgenetic alopecia (AGA) is correlated with a hyperandrogenic state and may be related to COVID‐19 severity. Furthermore, recent research has assessed the plausible association of AGA and COVID‐19. In this review, we investigate all evidence on AGA and its relationship with COVID‐19, including the possible role of androgens in COVID‐19 severity and outcomes as well as candidate androgen‐related drugs for the treatment of COVID‐19.

Clinical Patterns of Hair Loss in Men: Is Dihydrotestosterone the Only Culprit?

A number of pathways and factors including oxidative stress, inflammation, prostaglandins, vasculogenesis, Wnt/β-catenin, and transforming growth factor-β have been shown to be important in male androgenetic alopecia. There is limited but increasing evidence of the potential usefulness of antioxidants, anti-inflammatory agents, prostaglandins, and growth factors for treating of androgenetic alopecia. Lifestyle factors and comorbidities including cardiovascular risk factors have been shown to be associated with male androgenetic alopecia. Further study of these pathways, factors, and comorbidities is needed to better understand the pathophysiology, find potentially useful therapeutic targets, and ensure a comprehensive approach to the management of androgenetic alopecia in men.

Brassica oleracea extract, glucosinlates, and sulforaphane promote hair growth in vitro and ex vivo

BACKGROUND

Androgenic alopecia (AGA) is the most common type of hair loss, in which dihyrotestosterone (DHT) plays a crucial role via modulating androgen receptors in hair follicles.

AIMS

The current objective is to search for new therapy of AGA.

METHODS

In the present study, we investigated the effects of sulforaphane, its precursor glucosinlates and glucosinlates-enriched Brassica oleracea L.var.italic Planch extract (BOE) on the growth of hair follicle and the related matrix cell viability, as well as the possible underlying mechanisms in vitro and ex vivo.

RESULTS

We observed that BOE, glucosinlates, and sulforaphane can prevent the testosterone-induced inhibition of dermal papilla (DP) cells viability. BOE and sulforaphane can even hinder the testosterone-induced inhibition of HaCaT cells viability. Moreover, BOE, glucosinlates, and sulforaphane can up-regulate the cytokeratin gene expression in HaCaT cells, prevent the increase in Bax gene levels induced by testosterone in DP, and promote the growth of hair follicle of mice. These effects can be linked to the enhancement of DP and HaCaT cells activities and the prevention of the testosterone-induced cell apoptosis of DP cells.

CONCLUSIONS

Taken together, BOE, glucosinlates, and sulforaphane can promote the growth of hair follicle of mice and can be used as potential treatment agents for androgenic alopecia.

Efficacy and Safety of Oral Minoxidil 5 mg Once Daily in the Treatment of Male Patients with Androgenetic Alopecia: An Open-Label and Global Photographic Assessment

Introduction

Oral minoxidil is an antihypertensive vasodilator known to stimulate hair growth. The use of low-dose oral minoxidil for the treatment of male androgenetic alopecia (AGA) is receiving increasing attention. The aim of this study was to evaluate the efficacy and safety of oral minoxidil for the treatment of male AGA.

Methods

This was an open-label, prospective, single-arm study. Thirty men aged 24–59 years with AGA types III vertex to V were treated with oral minoxidil 5 mg once daily for 24 weeks. Efficacy was evaluated by hair counts, hair diameter measurements, photographic assessment, and self-administered questionnaire. The safety of the treatment was closely monitored by means of physical examinations and laboratory investigations.

Results

There was a significant increase in total hair counts from baseline at weeks 12 (mean change + 26, range 182.5–208.5 hairs/cm²) and 24 (mean change + 35.1, range 182.5–217.6 hairs/cm²) (both p = 0.007). Photographic assessment of the vertex area by an expert panel revealed 100% improvement (score > + 1), with 43% of patients showing excellent improvement (score + 3, 71–100% increase). The frontal area also showed a significant response but less than that of the vertex area. Common side effects were hypertrichosis (93% of patients) and pedal edema (10%). No serious cardiovascular adverse events and abnormal laboratory findings were observed.

Conclusion

Oral minoxidil 5 mg once daily effectively increased hair growth in our male patients with AGA and had a good safety profile in healthy subjects. However, oral minoxidil should be used carefully with men who have severe hypertension and increased risk for cardiovascular events.

Electronic supplementary material

The online version of this article (10.1007/s13555-020-00448-x) contains supplementary material, which is available to authorized users.

Evaluation of Hair Density and Hair Diameter in the Adult Thai Population Using Quantitative Trichoscopic Analysis

The data of hair density and hair diameter in the Asian population, especially in Thais, are limited. We aimed to evaluate hair density and hair diameter of members of the Thai population at different scalp sites and to determine the effect of sex and aging as well as to compare the results with those in groups of other ethnicities. Healthy Thais whose hair examination findings were normal were evaluated. Two hundred and thirty-nine subjects participated in this study, of whom 79 were male and 160 were female. Hair density and hair diameter were analyzed at four different scalp sites using quantitative trichoscopic analysis. The highest hair density in Thais was observed in the vertex area. Hair densities at four different scalp sites were significantly different from one another; only hair density at the vertex site showed no significant difference from that in the occipital area. In contrast, hair diameter did not show any statistically significant differences for the different sites. We observed decreased mean hair density with increasing age and found statistically significant differences between participants in their 20s and those in their 60s, while hair diameter remained consistent. Comparing our results with a previous study in other ethnicities, the hair densities in Asians are generally lower. In conclusion, hair density in the Thai population varies at different scalp sites. Aging is a factor in declining hair density. Asians have a lower hair density compared to Caucasian and African populations.

A Portable Electrospinner for Nanofiber Synthesis and Its Application for Cosmetic Treatment of Alopecia

A portable, handheld electrospinning apparatus is designed and constructed using off-the-shelf components and 3D-printed parts. The portable electrospinner is used to generate nanofibers with diameters ranging from 85 to 600 nm; examination of these fibers is achieved with scanning electron microscopy. This portable electrospinner has similar capabilities to standard stationary benchtop electrospinners in terms of the diversity of polymers the device is able to spin into nanofibers and their resulting size and morphology. However, it provides much more ambulatory flexibility, employs current-limiting measures that allow for safer operation and is cost effective. As a demonstration of the device's unique application space afforded by its portability, the device is applied in direct-to-skin electrospinning to improve the aesthetics of simulated hair loss in a mouse model by electrospinning dyed polyacrylonitrile nanofibers that mimic hair. The superficial nanofiber treatment for thinning hair is able to achieve an improvement in appearance similar to that of a commercially available powder product but outperforms the powder in the nanofiber's superior adherence to the affected area. The portable electrospinning apparatus overcomes many limitations of immobile benchtop electrospinners and holds promise for applications in consumer end-use scenarios such as the treatment of alopecia via cosmetic hair thickening.

Phospholipid-polymer hybrid nanoparticle-mediated transfollicular delivery of quercetin: prospective implement for the treatment of androgenic alopecia

Objectives: The aim of the study was to deliver effective doses of quercetin (Que) to the lower region of hair follicles (HFs) using the transfollicular route through dipalmotylphosphatidylcholine (DPPC)-reinforced poly lactide-co- glycolide nanoparticles (DPPC-PLGA hybrid NPs) for the treatment of alopecia. Method: PLGA and DPPC-PLGA hybrid NPs were prepared by double-emulsification solvent evaporation method. NPs were characterized for size, shape, zeta potential entrapment and drug release. Drug-polymer interactions were determined by infrared spectroscopy (Fourier transform infrared spectroscopy, FTIR) and differential scanning calorimetry (DSC). Follicular uptake of fluorescent marker tagged NPs was assessed on isolated rat skin by fluorescent microscopy. Potential of hybrid NPs to induce hair regrowth was tested on testosterone-induced alopecia in rat models by visual inspection, hair follicular density measurement (no./mm), and histological skin tissue section studies. Key findings: Hybrid NPs had mean vesicles size 339 ± 1.6, zeta potential -32.6 ± 0.51, and entrapment efficiency 78 ± 5.5. Cumulative drug release after 12 h was found to be 47.27 ± 0.79%. FTIR and DSC confirmed that drug was independently dispersed in the amorphous form in the polymer. Data from fluorescence microscopy suggested that NPs were actively taken up by HFs. In-vivo studies on alopecia-induced rat models showed that hybrid NPs improved hair regrowth potential of Que and accumulation of NPs at HFs end region inhibit HFs cells apoptosis. Conclusion: This study concludes that phospholipid-polymer hybrid NPs could be the promising transfollicular delivery system for Que in the treatment of androgenic alopecia management.

Age, lifestyle and self-perceptions of hair: Is there an association with hair diameter and tensile properties?

OBJECTIVE

To determine the association of age, lifestyle habits and the self-perception of hair condition with the objectively measured physical properties of hair in Caucasian females with brown hair.

METHODS

Hair biophysical properties, lifestyle habits data and self-perceptions of hair condition were collected on 110 Caucasian females with brown hair ranging in age from 17 to 78. Hair diameter (cross-sectional area) and tensile properties (elastic modulus, break strength and break extension) were measured at the root end of individual fibres (n = 100/subject) from the crown and frontal regions using objective instrumental methods. Other measures included body mass index (BMI) and Savin female pattern hair loss grades based on judging of standardized front, top and side view head images. Lifestyle habits and practices and self-perceived hair condition were obtained via a standardized self-assessment questionnaire.

RESULTS

Hair fibre diameter and break extension decreased significantly with age. Hair fibre elastic modulus and Savin hair loss scores increased significantly with age. No age-related change in hair fibre break stress was observed. A history of smoking or being overweight was significantly associated with having lower hair fibre cross-sectional area but was not associated with any of the measured tensile properties. Subjects who perceived their hair as fine, thinning or weak had significantly lower cross-sectional areas than subjects who did not. Subjects who perceived their hair to be healthy or strong had significantly higher cross-sectional areas than subjects who did not.

CONCLUSION

The biophysical properties of hair change significantly with age. A history of smoking or being overweight was significantly associated with having smaller hair cross-sectional area but was not associated with differences in hair tensile properties. The self-perception of having strong or healthy hair seems more associated with having a larger cross-sectional area than any real differences in hair strength.Abstrait.

Histopathology of aging of the hair follicle

Hair follicles experience several changes with aging, the most noticeable of which is graying of the hair shaft due to loss of melanin. Additional changes in the diameter and length of the hair have contributed to the concept of senescent alopecia, which is different from androgenetic alopecia according to most. Graying happens in most individuals, although in different grades and starting at different ages. It is related to a decrease in the number and activity of the melanocytes of the hair bulb, which eventually completely disappear from the bulb of the white hair. Residual non-active melanocytes remain in the outer root sheath and in the bulge, which allows for repigmentation of the hair under certain stimuli or conditions.

[Postmenopausal lichen planopilaris also known as fibrosing frontotemporal alopecia Kossard : An evidence-oriented practical guide to treatment from the University of the Saarland, Hair Research Center of the Dr. Rolf M. Schwiete Foundation]

Postmenopausal lichen planopilaris (PLPP), also known as fibrosing frontotemporal alopecia Kossard (FFAK), is a not uncommon inflammatory scalp disease affecting approximately 5% of patients at specialized hair centers. The overall incidence of sporadic occurrence is believed to be just under 1% in the older, predominantly female, general population. Since the disease is often undiagnosed, it is statistically likely to be underrepresented. It especially occurs in postmenopausal women who are in the 6th and 7th decade of life (90%), but also in about 10% of premenopausal women, and in men it is documented only in isolated cases. The result is a permanent scarring hair loss accentuated at the front hairline with backward movement towards the neck mostly accompanied by a typical loss of the eyebrows. The disease therefore often leads to significant mental distress and social anxiety in those affected. This is the basis for a compelling need to develop evidence-based therapeutic concepts. While numerous retrospective case series have characterized the phenomenology of FFAK very well, to date there are no randomized controlled trials on evidence-based therapy. Here, we present the Homburger Evidence-Oriented Therapy Algorithm, which is oriented along the available case series evidence: It may (1) serve as a therapy guide for practice and (2) can be used as a basis for working out reliable data based on study evidence. The article contains detailed practical information on photo documentation, biopsy and histological processing up to the practical implementation of, for example, intralesional steroid therapy as well as information on selection criteria for suitable systemic therapies.

Types of hairline recession in androgenetic alopecia and perceptions of aging in Asian males

BACKGROUND

Cranial hair loss is one of the characteristics of age. Hairline recession has been confirmed adversely to affect the perceptions of age in Western males. However, comparatively little is known about the effect of frontal recession on the perceived facial age (PFA) of East Asian males. Moreover, specific roles of different types of hairline recession in PFA of different age groups still remain a mystery.

OBJECTIVE

To investigate and quantify the effect of different types of hairline recession on PFA in East Asian young males of different age groups.

METHODS

Thirty non-bald males were selected and divided equally into three groups (20s, 30s, and 40s). With the aid of modern software, the frontoparietal area of facial images from 30 experimenters was modified into three basic types of hair loss (M₂ , C₂ , and U₂ ) according to the basic and specific classification of androgenic alopecia. In a web-based survey, approximately 900 naive participants were asked to estimate the PFA of males from their original and modified facial images.

RESULTS

Perceived facial age increased to 1.58 ± 0.79, 4.19 ± 1.27, and 5.90 ± 1.00 years when the original facial images were modified to have hair loss types M₂ , C₂ , or U₂ , respectively. In addition, the PFA of males with hair loss type C₂ or U₂ appeared significantly older than the original facial images in the 30s group.

CONCLUSION

Different types of hairline recession can increase the PFA to different degrees in East Asian males of different age groups.

Association between male pattern baldness and testicular germ cell tumor: a meta-analysis

BACKGROUND

The relationship between male pattern baldness and incidence of testicular cancer remains inconclusive. Hence, we performed the present meta-analysis based on all eligible case-control studies.

METHODS

A comprehensive literature search was performed in July 30th 2018 based on PUBMED, EMBASE and Web of science database. Pooled odds ratio(OR) and its 95% confidence intervals (95% CIs) was calculated with a DerSimonian and Laird random-effects.

RESULTS

The pooled results were included in this meta-analysis. Overall, We have demonstrated statistically signification between baldness(any pattern) and testicular cancer was identified (OR: 0.61, 95% CI:0.50-0.74). There was no obvious heterogeneity across included studies (P = 0.22 for heterogeneity, I2 = 30%). When subgroup analysis by types of baldness, We found a statistically significant association was observed that baldness(I-VII) might become a protective factor for the risk of testicular germ cell tumor(TGCT). There was no definite connection between alopecia and the different types of TGCT.

CONCLUSION

Individuals with any pattern baldness may have a decreased risk of testicular cancer, all of analyses studies are warranted to confirm our preliminary findings. According to subgroup analysis of different hair loss grades, we found that 2 stage(II) hair loss can decrease more strongly testicular cancer risk than any other grades. Despite of our findings, We still need further researches to advance knowledge in this field.

Harvested vs estimated follicular units in hair transplantation

BACKGROUND

The follicular unit transplantation strip harvesting surgery is one of the gold standard methods of hair transplantation; the counting follicular unit ratio and hair density is a major step in donor site evaluation.

AIMS

We conducted the study for analyzing the preoperative donor site evaluation and comparison of the actual harvested and estimated follicular units in hair transplantation.

PATIENTS/METHODS

In this retrospective study, we enrolled 65 male patients with androgenetic alopecia who underwent follicular unit transplantation. Before the donor strip harvesting procedure, we counted the follicular unit density and calculated the percentage of each follicular unit. And then, we compared them to actual harvesting grafts.

RESULT

The number of actual harvested transplanted hairs (3162.22 ± 958.30) were less than estimated transplanted hairs (3319.25 ± 1007.86). Both the number and percentage of actual harvested 1-hair follicular unit were more than estimated 1-hair follicular unit. In contrast, the number and percentage of actual harvested 3-hair follicular unit was less than estimated 3-hair follicular unit. The follicular unit density was lower in older patients. Those received more than one session of hair transplantation tended to have lower follicular and hair density (P = 0.007 and 0.01, respectively). The scalp laxity was lower in older patients and those received multiple sessions of hair transplantation.

CONCLUSION

The actual harvested grafts yield more 1-hair follicular units and less 3-hair follicular units than estimation. Old age and multiple sessions of hair transplantation caused more limitation of harvesting donor scalp.

Retrospective Assessment of Follicular Unit Density in Asian Men With Androgenetic Alopecia

BACKGROUND

Hair density, together with hair diameter has a tremendous impact on the cosmetic outcome of hair transplantation surgery.

OBJECTIVE

This retrospective study aims to assess the average number of follicular unit (FU) grafts in the donor area of Asian men with androgenetic alopecia.

METHODS

Seventy patients (ages 24-65 years old) with virgin scalp who had their first hair transplantation were included. During the harvesting procedure, a 2- to 3-cm-wide area of the donor site was shaved from ear to ear with 5 specific areas assigned as reference points for the study namely the central occipital area, left and right parietal and temporal areas. A video microscope was used to capture the field of each reference point. Follicular units in each area were counted and the number of 1-hair, 2-hair, and 3-hair follicular groupings was recorded.

RESULTS

East and Southeast Asians had an average of 61.1 FU/cm (111.2 hairs/cm); West Asians had an average density of 63.6 FU/cm (126.8 hairs/cm); South Asians were noted to have an average density of 63.5 FU/cm (126.8 hairs/cm).

CONCLUSION

Asian hair density has slight variations in the number of FU grafts in each donor area.

Hair follicle characteristics as early marker of Type 2 Diabetes

Type 2 Diabetes mellitus (DM2) includes a continuum of metabolic disorders characterized by hyperglycemia that causes several chronic long-term complications such as coronary artery disease, peripheral arterial disease, nephropathy, and neuropathy. The hair follicle could reveal signs of early vascular impairment, yet its relationship to early metabolic injuries has been largely ignored. We propose that in earlier stages of the continuum of DM2-related metabolic disorders, a group of susceptible patients who do not yet meet the diagnostic criteria to be considered as persons with DM2 may present chronic vascular impairment and end organ damage, including hair follicle damage, which can be evaluated to identify an early risk marker. This hypothesis is based in the association found between insulin resistance and alopecia in non-diabetic persons, and the hair loss on the lower limbs as a manifestation of long-term peripheral arterial disease among subjects with DM2. In order to test this hypothesis, studies are required to evaluate if hair follicle characteristics are related to and can predict hyperglycemic complications, and if they do so, which feature of the hair follicle, such as hair growth, best characterizes such DM2-related conditions. If this hypothesis were proven to be true, significant advances towards a personalized approach for early prevention strategies and management of DM2 would be made. By focusing on the hair follicles, early stages of metabolic-related organ damage could be identified using non-invasive low-cost techniques. In so doing, this approach could provide early identification of DM2-susceptible individuals and lead to the early initiation of adequate primary prevention strategies to reduce or avoid the onset of large internal organ damage.

Promotion Effect of Apo-9'-fucoxanthinone from Sargassum muticum on Hair Growth via the Activation of Wnt/β-Catenin and VEGF-R2

This study was conducted to evaluate the effects of Sargassum muticum extract and apo-9'-fucoxanthinone, a principal component of S. muticum, on hair growth. When rat vibrissa follicles were treated with S. muticum extract for 21 d, the hair-fiber lengths for the vibrissa follicles increased significantly. Treatment with the S. muticum extract and the EtOAc fraction of the S. muticum extract markedly increased the proliferation of dermal papilla cells (DPCs) and decreased the 5α-reductase activity. In addition, the EtOAc fraction of the S. muticum extract significantly promoted anagen initiation in C57BL/6 mice. Especially, apo-9'-fucoxanthinone, an active constituent from the S. muticum extract, caused an increase in DPC proliferation and a decrease in 5α-reductase activity. To elucidate the molecular mechanisms of apo-9'-fucoxanthinone on the proliferation of DPCs, we examined the level of various signaling proteins. Apo-9'-fucoxanthinone increased the level of vascular endothelial growth factor receptor-2 (VEGF-R2), Wnt/β-catenin signaling proteins such as phospho(ser9)-glycogen synthase kinase-3β (GSK-3β) and phospho(ser552)-β-catenin, whereas apo-9'-fucoxanthinone did not affect the transforming growth factor-β (TGF-β) signaling proteins such as Smad2/3. These results suggest that apo-9'-fucoxanthinone from S. muticum could have the potential for hair growth with DPC proliferation via the activation of Wnt/β-catenin signaling and the VEGF-R2 pathway.

In silico prediction of prostaglandin D2 synthase inhibitors from herbal constituents for the treatment of hair loss

ETHNOPHARMACOLOGICAL RELEVANCE

Many herbal topical formulations have been marketed worldwide to prevent hair loss or promote hair growth. Certain in vivo studies have shown promising results among them; however, the effectiveness of their bioactive constituents remains unknown.

AIM OF THE STUDY

Recently, prostaglandin D2 (PGD2) inhibition has been discovered as a pharmacological mechanism for treating androgenic alopecia (AGA). This present study was aimed to identify prostaglandin D2 synthase (PTGDS) inhibitors in traditional Chinese medicines (TCMs) for treating AGA.

MATERIALS AND METHODS

In this study, 389 constituents of 12 selected herbs were docked into 6 different crystal structures of PTGDS. The accuracy of the docking methods was successfully validated with experimental data from the ZINC In Man (Zim) database using receiver operating characteristic (ROC) studies. Seven essential drug properties were predicted for topical formulation: skin permeability, sensitisation, irritation, corrosion, mutagenicity, tumorigenicity and reproductive effects.

RESULTS

Many constituents of the twelve herbs were found to have more advanced binding energies than the experimentally proved PTGDS inhibitors, but many of them were indicative of at least one type of skin adverse reactions, and exhibited poor skin permeability.

CONCLUSIONS

Overall, ricinoleic acid, acteoside, amentoflavone, quercetin-3-O-rutinoside and hinokiflavone were predicted to be PTGDS inhibitors with good pharmacokinetic properties and minimal adverse skin reactions. These compounds have the highest potential for further in vitro and in vivo investigation with the aim of developing safe and high-efficacy hair loss treatment.

Evaluation of DNA variants associated with androgenetic alopecia and their potential to predict male pattern baldness

Androgenetic alopecia, known in men as male pattern baldness (MPB), is a very conspicuous condition that is particularly frequent among European men and thus contributes markedly to variation in physical appearance traits amongst Europeans. Recent studies have revealed multiple genes and polymorphisms to be associated with susceptibility to MPB. In this study, 50 candidate SNPs for androgenetic alopecia were analyzed in order to verify their potential to predict MPB. Significant associations were confirmed for 29 SNPs from chromosomes X, 1, 5, 7, 18 and 20. A simple 5-SNP prediction model and an extended 20-SNP model were developed based on a discovery panel of 305 males from various European populations fitting one of two distinct phenotype categories. The first category consisted of men below 50 years of age with significant baldness and the second; men aged 50 years or older lacking baldness. The simple model comprised the five best predictors: rs5919324 near AR, rs1998076 in the 20p11 region, rs929626 in EBF1, rs12565727 in TARDBP and rs756853 in HDAC9. The extended prediction model added 15 SNPs from five genomic regions that improved overall prevalence-adjusted predictive accuracy measured by area under the receiver characteristic operating curve (AUC). Both models were evaluated for predictive accuracy using a test set of 300 males reflecting the general European population. Applying a 65% probability threshold, high prediction sensitivity of 87.1% but low specificity of 42.4% was obtained in men aged <50 years. In men aged ≥50, prediction sensitivity was slightly lower at 67.7% while specificity reached 90%. Overall, the AUC=0.761 calculated for men at or above 50 years of age indicates these SNPs offer considerable potential for the application of genetic tests to predict MPB patterns, adding a highly informative predictive system to the emerging field of forensic analysis of externally visible characteristics.