Br J Dermatol. 2014 Nov;171(5):1031-43. doi: 10.1111/bjd.13114. Epub 2014 Oct 30.

Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and transforming growth factor-β2/insulin-like growth factor-1-mediated regulation of the hair cycle in male and female human hair follicles in vitro.

Fischer TW1, Herczeg-Lisztes E, Funk W, Zillikens D, Bíró T, Paus R.

Author information

Abstract

BACKGROUND:

Caffeine reportedly counteracts the suppression of hair shaft production by testosterone in organ-cultured male human hair follicles (HFs).

OBJECTIVES:

We aimed to investigate the impact of caffeine (i) on additional key hair growth parameters, (ii) on major hairgrowth regulatory factors and (iii) on male vs. female HFs in the presence of testosterone.

METHODS:

Microdissected male and female human scalp HFs were treated in serum-free organ culture for 120 h with testosterone alone (0·5 μg mL(-1)) or in combination with caffeine (0·005-0·0005%). The following effects on hair shaft elongation were evaluated by quantitative (immuno)histomorphometry: HF cycling (anagen-catagen transition); hair matrix keratinocyte proliferation; expression of a key catagen inducer, transforming growth factor (TGF)-β2; and expression of the anagen-prolonging insulin-like growth factor (IGF)-1. Caffeine effects were further investigated in human outer root sheath keratinocytes (ORSKs).

RESULTS:

Caffeine enhanced hair shaft elongation, prolonged anagen duration and stimulated hair matrix keratinocyte proliferation. Female HFs showed higher sensitivity to caffeine than male HFs. Caffeine counteracted testosterone-enhanced TGF-β2 protein expression in male HFs. In female HFs, testosterone failed to induce TGF-β2 expression, while caffeine reduced it. In male and female HFs, caffeine enhanced IGF-1 protein expression. In ORSKs, caffeine stimulated cell proliferation, inhibited apoptosis/necrosis, and upregulated IGF-1 gene expression and protein secretion, while TGF-β2 protein secretion was downregulated.

CONCLUSIONS:

This study reveals new growth-promoting effects of caffeine on human hair follicles in subjects of both sexes at different levels (molecular, cellular and organ).

© 2014 British Association of Dermatologists.

Toxicol Res. 2014 Dec;30(4):297-304. doi: 10.5487/TR.2014.30.4.297.

Peppermint Oil Promotes Hair Growth without Toxic Signs.

Oh JY1, Park MA2, Kim YC2.

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Abstract

Peppermint (Mentha piperita) is a plant native to Europe and has been widely used as a carminative and gastric stimulant worldwide. This plant also has been used in cosmetic formulations as a fragrance component and skin conditioning agent. This study investigated the effect of peppermint oil on hair growth in C57BL/6 mice. The animals were randomized into 4 groups based on different topical applications: saline (SA), jojoba oil (JO), 3% minoxidil (MXD), and 3% peppermint oil (PEO). The hair growth effects of the 4-week topical applications were evaluated in terms of hair growth, histological analysis, enzymatic activity of alkaline phosphatase (ALP), and gene expression of insulin-like growth factor-1 (IGF-1), known bio-markers for the enhanced hair growth. Of the 4 experimental groups, PEO group showed the most prominent hairgrowth effects; a significant increase in dermal thickness, follicle number, and follicle depth. ALP activity and IGF-1expression also significantly increased in PEO group. Body weight gain and food efficiency were not significantly different between groups. These results suggest that PEO induces a rapid anagen stage and could be used for a practical agent forhair growth without change of body weight gain and food efficiency.

KEYWORDS:

Alkaline phosphatase; Hair follicle; Hair growth; Insulin-like growth factor-1; Peppermint oil

PMID:

 

25584150

 

[PubMed] 

PMCID:

 

PMC4289931

 

Free PMC Article

Naunyn Schmiedebergs Arch Pharmacol. 2014 Dec 2. [Epub ahead of print]

Baicalin, a flavonoid, affects the activity of human dermal papilla cells and promotes anagen induction in mice.

Shin SH1, Bak SS, Kim MK, Sung YK, Kim JC.

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Abstract

Baicalin, a flavonoid isolated from Scutellaria baicalensis, is known to have multiple biological functions. Recent studies have demonstrated that baicalin treatment increases alkaline phosphatase activity (ALP) and osteoprotegerin secretion by osteoblasts. Furthermore, baicalin induces the differentiation of cultured osteoblasts via the activation of the Wnt/β-catenin signaling pathway. In this study, we evaluated the hair growth-promoting effects of baicalin in human follicular dermal papilla (DP) cells. A reporter assay and Western blotting were used to assess the effect of baicalin on β-catenin signaling in DP cells. ALP activity and messenger RNA (mRNA) expression were examined by ALP staining and real-time polymerase chain reaction (PCR), respectively. Growth factor expression levels were also evaluated using real-time PCR. Finally, the effect of baicalin on hair growth in vivo was examined by topical application of baicalin on the shaved dorsal skin of C57BL/6 mice. Our results indicate that baicalin activates Wnt/β-catenin signaling in a dose-dependent manner in human DP cells. ALP mRNA expression and activity were significantly induced in the presence of baicalin. In addition, treatment with baicalin induced the mRNA expression of growth factors, such as insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF). Moreover, compared to vehicle treatment, baicalin treatment induced an earlier conversion from telogen to anagen. Our results strongly suggest that baicalin promotes hair growth by regulating the activity of DP cells.

http://www.ncbi.nlm.nih.gov/pubmed/25434532

Acta Otolaryngol. 2015 Mar 5:1-5. [Epub ahead of print]

The minimum peptides of IGF-1 and substance P protect vestibular hair cells against neomycin ototoxicity.

Yoshida S1, Sugahara K, Hashimoto M, Hirose Y, Shimogori H, Yamashita H.

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Abstract

Abstract Conclusions: Our data indicate that SSSR and SSSR + FGLM-NH2 protect sensory hair cells against neomycin-induced death in the vestibular epithelium. In addition, the results show that SSSR and FGLM-NH2 can be used as protective molecules against aminoglycoside ototoxicity. Objectives: This study investigated the role of the peptides SSSR and SSSR + FGLM-NH2 in mammalian vestibular hair cell death induced by aminoglycoside. Methods: Cultured utricles from mature CBA/N mice were used in this study. The cultured utricles were assigned to five groups (control group, neomycin group, neomycin + SSSR group, neomycin + FGLM-NH2 group, and neomycin + SSSR + FGLM-NH2 group). Aat 24 h after exposure to neomycin, the hair cells were labeled immunohistochemically, and the rate of survival of vestibular hair cells was evaluated using a fluorescence microscope. Results: The rate of survival of vestibular hair cells was significantly higher in the neomycin + SSSR and neomycin + SSSR + FGLM-NH2 groups than in the neomycin group. The results suggest that SSSR could protect hair cells against aminoglycoside ototoxicity.

KEYWORDS:

FGLM-NH2; SSSR; aminoglycoside; hair cell degeneration

Appl Ergon. 2015 May;48:177-85. doi: 10.1016/j.apergo.2014.11.007. Epub 2014 Dec 25.

The effect of hair density on the coupling between the tactor and the skin of the human head.

Myles K1, Kalb JT2, Lowery J3, Kattel BP4.

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Abstract

The purpose of this study was to determine the effect of hair density on vibration detection thresholds associated with the perception of low frequency vibration stimuli applied to the head. A host of tactile sensitivity information exists for other parts of the body, however the same information is lacking for the head. Thirty-three college students, age 18-35, were recruited for the study. A mixed design was used to evaluate the effect of hair density, head location, and frequency on vibration detection thresholds. Results suggest that hair density might slightly impede vibration signals from reaching the scalp and reduce vibration sensitivity, for the least sensitive locations on the head. This research provides design recommendations for head-mounted tactile displays for women and those with hair that can be used to convey directional cues for navigation and as alerts to critical events in the environment.

Published by Elsevier Ltd.

Dev Cell. 2014 Dec 8;31(5):543-58. doi: 10.1016/j.devcel.2014.10.022. Epub 2014 Nov 26.

Hair follicle dermal stem cells regenerate the dermal sheath, repopulate the dermal papilla, and modulate hair type.

Rahmani W1, Abbasi S1, Hagner A1, Raharjo E1, Kumar R2, Hotta A3, Magness S4, Metzger D5, Biernaskie J6.

Author information

Abstract

The dermal papilla (DP) provide instructive signals required to activate epithelial progenitors and initiate hair follicle regeneration. DP cell numbers fluctuate over the hair cycle, and hair loss is associated with gradual depletion/atrophy of DP cells. How DP cell numbers are maintained in healthy follicles remains unclear. We performed in vivo fate mapping of adult hair follicle dermal sheath (DS) cells to determine their lineage relationship with DP and found that a subset of DS cells are retained following each hair cycle, exhibit self-renewal, and repopulate the DS and the DP with new cells. Ablating these hair follicle dermal stem cells and their progeny retarded hair regrowth and altered hair type specification, suggesting that they function to modulate normal DP function. This work identifies a bipotent stem cell within the adult hair follicle mesenchyme and has important implications toward restoration of hair growth after injury, disease, and aging.

The expression of insulin-like growth factor 1 in follicular dermal papillae correlates with therapeutic efficacy of finasteride in androgenetic alopecia.

The expression of insulin-like growth factor 1 in follicular dermal papillae correlates with therapeutic efficacy of finasteride in androgenetic alopecia. 



Tang L1, Bernardo O, Bolduc C, Lui H, Madani S, Shapiro J. 
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Abstract 
BACKGROUND: 
It is generally believed that dihydrotestosterone is one of the pivotal mediators of hair loss in androgenetic alopecia (AGA). Finasteride, which blocks the conversion of testosterone to dihydrotestosterone, has now become an integral part of the current treatment approaches for male AGA. Several lines of evidence support the notion that dermal papilla (DP) cells represent the androgen target within the hair follicle. The specific molecular regulators modulated by androgens within hair follicles in the balding scalp are unknown. 
OBJECTIVE: 
The purpose of this study was to identify and quantify changes in expression of specific molecular hair growth regulators in DP of men with AGA treated with finasteride and correlate these findings to clinical efficacy. 
METHODS: 
Biopsy specimens were collected from 9 male patients from both the balding area and nonbalding occipital area before and after 4 months of finasteride therapy. DP were microdissected and total RNA was extracted from an equal number of DP from each biopsy specimen. The expression of various cytokines, including insulin-like growth factor (IGF)-1, was determined by reverse transcription polymerase chain reaction. The signals were detected by autoradiography. All 9 patients were given finasteride for 1 year and evaluated for efficacy at month 12. Efficacy was graded on a 7-point scale on the basis of comparison with initial baseline photography. 
RESULTS: 
IGF-1 was up-regulated by finasteride treatment in 4 of 9 patients. Among the patients with increased IGF-1 expression, 3 of them showed moderate clinical improvement after 12 months of treatment and another patient remained unchanged. In contrast, 3 patients with decreased IGF-1 expression in the balding scalp showed clinical worsening after 12 months. The other 2 patients without noticeable change in IGF-1 expression showed either slight improvement or no change in their hair condition. 
CONCLUSION: 
In a small uncontrolled study of 9 patients with AGA, an increased expression of IGF-1 messenger RNA levels in the DP was associated with patient response to finasteride.