The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Ralf Paus - One of the best experts on this subject based on the ideXlab platform.
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Hair Growth-modulation by adrenergic drugs.
Experimental dermatology, 2007Co-Authors: Eva M.j. Peters, Marcus Maurer, Vladimir A. Botchkarev, D. S. Gordon, Ralf PausAbstract:Since we have recently shown that the β 2 -adrenoreceptor (β 2 -AR) expression of selected regions of the Hair follicle (HF) epithelium as well as the number of adrenergic nerve fibers in murine skin change in a Hair cycle-dependent manner, this has raised the possibility that adrenergic nerves may exert trophic functions during HF cycling. To further explore this concept, we have investigated the effect of neuro-pharmacological manipulations on Hair Growth (anagen) induction in quiescent telogen mouse skin in vivo. Here, we demonstrate that subcutaneous injections of the noradrenaline (NA)-depleting agent guanethidine, or of the neurotoxin 6-hydroxydopamine, but not of the β 2 -AR agonist isoproterenol induce a premature onset of anagen in the lower back skin of C57BL/6 mice. On day 20 after the start of treatment, more than 80% of the guanethidine-treated mice and ca. 65% of the 6-hydroxydopamine-treated (6-OHDA) mice exhibited premature skin darkening and Hair Growth at the site of drug application, whereas less than one-third of all control animals showed macroscopic signs of anagen development. This was confirmed by histology, demonstrating mature anagen VI HFs only at the immediate site of treatment with guanethidine or 6-OHDA as opposed to resting telogen HFs in the neighboring untreated skin area. This observation further supports the concept that sympathetic nerves are intimately involved in Hair Growth control and invites one to explore the neuro-pharmacological manipulation of piloneural interactions as a novel therapeutic strategy for the management of Hair Growth disorders.
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Hair Growth inhibition by psychoemotional stress: a mouse model for neural mechanisms in Hair Growth control.
Experimental dermatology, 2006Co-Authors: Eva M.j. Peters, Petra C. Arck, Ralf PausAbstract:Stress has long been discussed controversially as a cause of Hair loss. However, solid proof of stress-induced Hair Growth inhibition had long been missing. If psychoemotional stress can affect Hair Growth, this must be mediated via definable neurorendocrine and/or neuroimmunological signaling pathways. Revisiting and up-dating relevant background data on neural mechanisms of Hair Growth control, we sketch essentials of Hair follicle (HF) neurobiology and discuss the modulation of murine Hair Growth by neuropeptides, neurotransmitters, neurotrophins, and mast cells. Exploiting an established mouse model for stress, we summarize recent evidence that sonic stress triggers a cascade of molecular events including plasticity of the peptidergic peri- and interfollicular innervation and neuroimmune crosstalk. Substance P (SP) and NGF (nerve Growth factor) are recruited as key mediators of stress-induced Hair Growth-inhibitory effects. These effects include perifollicular neurogenic inflammation, HF keratinocyte apoptosis, inhibition of proliferation within the HF epithelium, and premature HF regression (catagen induction). Intriguingly, most of these effects can be abrogated by treatment of stressed mice with SP-receptor neurokinin-1 receptor (NK-1) antagonists or NGF-neutralizing antibodies - as well as, surprisingly, by topical minoxidil. Thus there is now solid in vivo-evidence for the existence of a defined brain- HF axis. This axis can be utilized by psychoemotional and other stressors to prematurely terminate Hair Growth. Stress-induced Hair Growth inhibition can therefore serve as a highly instructive model for exploring the brain-skin connection and provides a unique experimental model for dissecting general principles of skin neuroendocrinology and neuroimmunology well beyond the HF.
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Stress, Hair Growth Control, and the Neuro-Endocrine-Immune Connection
Allergo Journal, 2000Co-Authors: Ralf PausAbstract:“Stress” has long been associated with disturbances in Hair Growth and Hair pigmentation. Yet, little if any evidence has been provided so far that this real ly is more than a coincidental association. How ever, today, a wide range of experimental data sug gests that skin nerves can indeed modulate Hair fol licle (HF) development, Growth and/or cycling via the release of neurotransmitters, neuropeptides and/or even of neurotrophins. It is therefore con ceivable that stress-induced changes in the release of these agents from perifollicular sensory and autonomic nerve fibers can alter Hair Growth. In ad dition, most classical mediators of systemic stress responses (e.g., substance P, ACTH, CRH, prolactin, catecholamines) are now also appreciated as Hair Growth modulators. Moreover, the HF itself is a potent source of these stress mediators, and expresses cognate receptors for many of them. Final ly, mast cells, with their “central switchboard” function in neurogenic inflammation, have recent ly surfaced as Hair Growth modulators. Stress mediators, as well as skin neuropeptids and neurotransmitters, may, thus, impact Hair Growth in directly via the modulation of mast cell activities. As a prominent source of neurotrophins, the Hair follicle may influence its own innervation as well as neurotrophin-dependent mast cell functions. On this background, the present essay examines the available evidence that there are neural mechanisms of Hair Growth control, reports preliminary evi dence that stress actually can inhibit Hair Growth in mice, and discusses potential pathways by which stress may affect Hair Growth in the context of de fined neuro-endocrine-immune circuits.
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Hair Growth induction by substance P.
Laboratory investigation; a journal of technical methods and pathology, 1994Co-Authors: Ralf Paus, T. Heinzelmann, K D Schultz, J Furkert, Klaus Fechner, B M CzarnetzkiAbstract:Background In vitro, some neuropeptides, including the tachykinin, substance P (SP), act as Growth factors. The cyclic Growth of the richly innervated Hair follicle offers a model for probing such functions in a complex, developmentally regulated tissue interaction system under physiologic conditions. Dissecting the role of neuropeptides in this system may also reveal as yet obscure neural mechanisms of Hair Growth control. Experimental design The neuropeptide-releasing neurotoxin, capsaicin was injected intradermally, or SP slow-release formulations were implanted subcutaneously in the back skin of C57BL/6 mice with all follicles in the resting stage of the Hair cycle (telogen) in order to see whether this induced Hair Growth (anagen). In addition, the endogenous SP skin concentration and the activity of the main SP-degrading enzyme, neutral endopeptidase, were determined during the induced murine Hair cycle by high performance liquid chromatography-controlled radioimmuno-assay (SP) or by fluorometry (neutral endopeptidase). Results Both capsaicin and SP induced significant Hair Growth (anagen) in the back skin of telogen mice. This was associated with substantial mast cell degranulation. The endogenous SP skin concentration showed significant, Hair cycle-dependent fluctuations during the induced murine Hair cycle, which were largely independent of the activity of neutral endopeptidase. Conclusions SP may play a role in the neural control of Hair Growth. Whereas this pilot study does not address the underlying mechanisms of action, it demonstrates that SP has potential as a Hair Growth-stimulatory agent in vivo, and serves as a basis for exploring the role of tachykinins in epithelial-mesenchymal-neuroectodermal interaction systems like the Hair follicle.
V K Dixit - One of the best experts on this subject based on the ideXlab platform.
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Hair Growth focus on herbal therapeutic agent
Current Drug Discovery Technologies, 2015Co-Authors: Satish Patel, Vikas Sharma, Nagendra Singh Chauhan, Mayank Thakur, V K DixitAbstract:This review presents an overview on plants identified to possess Hair Growth activity in various ethno-botanical studies and surveys of tradition medicinal plants. It also highlights the developments in Hair rejuvenation strategies from 1926 till-date and reviews the potential of herbal drugs as safer and effective alternatives. There are various causes for Hair loss and the phenomenon is still not fully understood. The treatments offered include both natural or synthetic products to treat the condition of Hair loss (alopecia), nonetheless natural products are continuously gaining popularity mainly due to their fewer side effects and better formulation strategies for natural product extracts. Plants have been widely used for Hair Growth promotion since ancient times as reported in Ayurveda, Chinese and Unani systems of medicine. This review covers information about different herbs and herbal formulation that are believed to be able to reduce the rate of Hair loss and at the same time stimulate new Hair Growth. A focus is placed on their mechanism of action and the review also covers various isolated phytoconstituents possessing Hair Growth promoting effect.
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Hair Growth promoting activity of eclipta alba in male albino rats
Archives of Dermatological Research, 2008Co-Authors: Ram Kumar Roy, Mayank Thakur, V K DixitAbstract:Alopecia is a dermatological disorder with psychosocial implications on patients with Hair loss. Eclipta alba Hassk. is a well-known Ayurvedic herb with purported claims of Hair Growth promotion. In the reported work attempts were undertaken to evaluate petroleum ether and ethanol extract of E. alba Hassk. for their effect on promoting Hair Growth in albino rats. The extracts were incorporated into oleaginous cream (water in oil cream base) and applied topically on shaved denuded skin of albino rats. The time (in days) required for Hair Growth initiation as well as completion of Hair Growth cycle was recorded. Minoxidil 2% solution was applied topically and served as positive control for comparison. Hair Growth initiation time was significantly reduced to half on treatment with the extracts, as compared to control animals. The time required for complete Hair Growth was also significantly reduced. Quantitative analysis of Hair Growth after treatment with petroleum ether extract (5%) exhibited greater number of Hair follicles in anagenic phase (69 ± 4) which were higher as compared to control (47 ± 13). The result of treatment with 2 and 5% petroleum ether extracts were better than the positive control minoxidil 2% treatment.
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Development and evaluation of polyherbal formulation for Hair Growth–promoting activity
Journal of cosmetic dermatology, 2007Co-Authors: Ram Kumar Roy, Mayank Thakur, V K DixitAbstract:Summary Background Cuscuta reflexa (Roxb.), Citrullus colocynthis (Schrad.), and Eclipta alba (Hassk.) are traditionally acclaimed herbs for their Hair Growth–promoting potential. Aim In the present study, it was envisaged to prepare herbal formulations containing petroleum ether extracts of the three herbs in varying ratio and evaluating the formulations for the Hair Growth–promoting activity. Methods The formulations as well as minoxidil (2%) solution (positive control) were applied topically on shaved skin of rats, and the time required for initiation and completion of Hair Growth cycle was recorded. Results and conclusions Hair Growth initiation time was markedly reduced to one third on treatment with the prepared formulation compared with control animals. The time required for complete Hair Growth was also reduced by 32%. Quantitative analysis of Hair Growth cycle after treatment with formulations and minoxidil (2%) exhibited greater number of Hair follicles in anagenic phase compared with control. The results thus corroborate with the traditionally acclaimed Hair Growth–promoting capabilities of the plants. The prepared formulation also holds potential for treatment of alopecia.
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Effect of Citrullus colocynthis. on Hair Growth in Albino Rats
Pharmaceutical Biology, 2007Co-Authors: Ram Kumar Roy, Mayank Thakur, V K DixitAbstract:AbstractCitrullus colocynthis. Schrad (Cucurbitaceae) is a traditionally acclaimed Hair tonic in Ayurveda (the traditional Indian system of medicine). Studies were therefore undertaken to evaluate petroleum ether and ethanol extracts of C. colocynthis. for their effect on Hair Growth in albino rats. The extracts incorporated into oleaginous ointment base were applied topically on shaved denuded skin of albino rats. The time required for initiation of Hair Growth as well as completion of Hair Growth cycle was recorded. Minoxidil 2% solution was applied topically and served as the standard. Hair Growth initiation time was significantly reduced to half on treatment with the petroleum ether extracts compared with untreated control animals. The time required for complete Hair Growth was also considerably reduced. The treatment was successful in bringing a greater number of Hair follicles (>70%) to anagenic phase than standard minoxidil (67%). The result of treatment with 2 and 5% petroleum ether extracts were ...
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Effect of Citrullus coclocynthis Schrad on Hair Growth activity of albino rats
2007Co-Authors: M Thakur, Rk Roy, V K DixitAbstract:Citrullus colocynthis Schrad is a traditionally acclaimed Hair tonic in Indian system of medicine. Studies were therefore undertaken in order to evaluate petroleum ether and ethanolic extract of C colocynthis for their effect on Hair Growth in albino rats. The extracts incorporated into oleaginous ointment base were applied topically on shaved denuded skin of albino rats. The time required for initiation of Hair Growth as well as completion of Hair Growth cycle was recorded. Minoxidil 2% solution was applied topically and served as positive control. Hair Growth initiation time was significantly reduced to half on treatment with the extracts compared to control animals. The time required for complete Hair Growth was also considerably reduced. The treatment was successful in bringing a greater number of Hair follicles (>70%) in anagenic phase than standard minoxidil (67%). The results of treatment with 2% and 5% petroleum ether extracts were comparable to the positive control minoxidil. (author abstract)
Eva M.j. Peters - One of the best experts on this subject based on the ideXlab platform.
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Hair Growth-modulation by adrenergic drugs.
Experimental dermatology, 2007Co-Authors: Eva M.j. Peters, Marcus Maurer, Vladimir A. Botchkarev, D. S. Gordon, Ralf PausAbstract:Since we have recently shown that the β 2 -adrenoreceptor (β 2 -AR) expression of selected regions of the Hair follicle (HF) epithelium as well as the number of adrenergic nerve fibers in murine skin change in a Hair cycle-dependent manner, this has raised the possibility that adrenergic nerves may exert trophic functions during HF cycling. To further explore this concept, we have investigated the effect of neuro-pharmacological manipulations on Hair Growth (anagen) induction in quiescent telogen mouse skin in vivo. Here, we demonstrate that subcutaneous injections of the noradrenaline (NA)-depleting agent guanethidine, or of the neurotoxin 6-hydroxydopamine, but not of the β 2 -AR agonist isoproterenol induce a premature onset of anagen in the lower back skin of C57BL/6 mice. On day 20 after the start of treatment, more than 80% of the guanethidine-treated mice and ca. 65% of the 6-hydroxydopamine-treated (6-OHDA) mice exhibited premature skin darkening and Hair Growth at the site of drug application, whereas less than one-third of all control animals showed macroscopic signs of anagen development. This was confirmed by histology, demonstrating mature anagen VI HFs only at the immediate site of treatment with guanethidine or 6-OHDA as opposed to resting telogen HFs in the neighboring untreated skin area. This observation further supports the concept that sympathetic nerves are intimately involved in Hair Growth control and invites one to explore the neuro-pharmacological manipulation of piloneural interactions as a novel therapeutic strategy for the management of Hair Growth disorders.
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Hair Growth inhibition by psychoemotional stress: a mouse model for neural mechanisms in Hair Growth control.
Experimental dermatology, 2006Co-Authors: Eva M.j. Peters, Petra C. Arck, Ralf PausAbstract:Stress has long been discussed controversially as a cause of Hair loss. However, solid proof of stress-induced Hair Growth inhibition had long been missing. If psychoemotional stress can affect Hair Growth, this must be mediated via definable neurorendocrine and/or neuroimmunological signaling pathways. Revisiting and up-dating relevant background data on neural mechanisms of Hair Growth control, we sketch essentials of Hair follicle (HF) neurobiology and discuss the modulation of murine Hair Growth by neuropeptides, neurotransmitters, neurotrophins, and mast cells. Exploiting an established mouse model for stress, we summarize recent evidence that sonic stress triggers a cascade of molecular events including plasticity of the peptidergic peri- and interfollicular innervation and neuroimmune crosstalk. Substance P (SP) and NGF (nerve Growth factor) are recruited as key mediators of stress-induced Hair Growth-inhibitory effects. These effects include perifollicular neurogenic inflammation, HF keratinocyte apoptosis, inhibition of proliferation within the HF epithelium, and premature HF regression (catagen induction). Intriguingly, most of these effects can be abrogated by treatment of stressed mice with SP-receptor neurokinin-1 receptor (NK-1) antagonists or NGF-neutralizing antibodies - as well as, surprisingly, by topical minoxidil. Thus there is now solid in vivo-evidence for the existence of a defined brain- HF axis. This axis can be utilized by psychoemotional and other stressors to prematurely terminate Hair Growth. Stress-induced Hair Growth inhibition can therefore serve as a highly instructive model for exploring the brain-skin connection and provides a unique experimental model for dissecting general principles of skin neuroendocrinology and neuroimmunology well beyond the HF.
Oh Sang Kwon - One of the best experts on this subject based on the ideXlab platform.
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Novel effect of sildenafil on Hair Growth.
Biochemical and biophysical research communications, 2018Co-Authors: Hye-in Choi, Bo-mi Kang, Jeehee Jang, Sungjoo Tommy Hwang, Oh Sang KwonAbstract:Abstract Background Sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, is known to increase the intracellular level of cyclic guanosine monophosphate (cGMP), which causes vasodilation. However, the effect of sildenafil on human Hair follicles (hHFs) is unknown. Objective The purpose of this study was to determine the role of sildenafil in Hair Growth. Methods We investigated the expression of PDE5 in human dermal papilla cells (hDPCs) and hHFs. The effects of sildenafil on hDPC proliferation were evaluated using BrdU assays. The mRNA expression of Growth factors and extracellular signal-regulated kinase (ERK) phosphorylation were investigated using real-time PCR and western blotting, respectively. Additionally, anagen induction and perifollicular vessel formation were evaluated using an in vivo mice model. Results We confirmed high expression of PDE5 in hDPCs and hHFs. Sildenafil enhances proliferation of hDPCs and up-regulates the mRNA expression of vascular endothelial Growth factor (VEGF) and platelet-derived Growth factor (PDGF), which are responsible for Hair Growth. Additionally, sildenafil up-regulates the levels of phosphorylated ERK and accelerates anagen induction by stimulating perifollicular vessel formation after topical application in mice. Conclusion Our study demonstrates for the first time, the significant therapeutic potential of sildenafil on Hair Growth and its potential use in treatment of alopecia.
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Role of Arachidonic Acid in Promoting Hair Growth
Annals of dermatology, 2016Co-Authors: Semchin Munkhbayar, Hee Chul Eun, Kyu Han Kim, Sunhyae Jang, A-ri Cho, Soon-jin Choi, Chang Yup Shin, Oh Sang KwonAbstract:BACKGROUND Arachidonic acid (AA) is an omega-6 polyunsaturated fatty acid present in all mammalian cell membranes, and involved in the regulation of many cellular processes, including cell survival, angiogenesis, and mitogenesis. The dermal papilla, composed of specialized fibroblasts located in the bulb of the Hair follicle, contributes to the control of Hair Growth and the Hair cycle. OBJECTIVE This study investigated the effect of AA on Hair Growth by using in vivo and in vitro models. METHODS The effect of AA on human dermal papilla cells (hDPCs) and Hair shaft elongation was evaluated by MTT assay and Hair follicle organ culture, respectively. The expression of various Growth and survival factors in hDPCs were investigated by western blot or immunohistochemistry. The ability of AA to induce and prolong anagen phase in C57BL/6 mice was analyzed. RESULTS AA was found to enhance the viability of hDPCs and promote the expression of several factors responsible for Hair Growth, including fibroblast Growth factor-7 (FGF-7) and FGF-10. Western blotting identified the role of AA in the phosphorylation of various transcription factors (ERK, CREB, and AKT) and increased expression of Bcl-2 in hDPCs. In addition, AA significantly promoted Hair shaft elongation, with increased proliferation of matrix keratinocytes, during ex vivo Hair follicle culture. It was also found to promote Hair Growth by induction and prolongation of anagen phase in telogen-stage C57BL/6 mice. CONCLUSION This study concludes that AA plays a role in promoting Hair Growth by increasing the expression of Growth factors in hDPCs and enhancing follicle proliferation and survival.
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the additive effects of minoxidil and retinol on human Hair Growth in vitro
Biological & Pharmaceutical Bulletin, 2007Co-Authors: Hyeon Gyeong Yoo, Oh Sang Kwon, Hyun Keol Pyo, Hee Chul Eun, Inyoung Chang, Yong Jung Kang, Seung Ho Lee, Kwang Hyun Cho, Kyu Han KimAbstract:Minoxidil enhances Hair Growth by prolonging the anagen phase and induces new Hair Growth in androgenetic alopecia (AGA), whereas retinol significantly improves scalp skin condition and promotes Hair Growth. We investigated the combined effects of minoxidil and retinol on human Hair Growth in vitro and on cultured human dermal papilla cells (DPCs) and epidermal keratinocytes (HaCaT). The combination of minoxidil and retinol additively promoted Hair Growth in Hair follicle organ cultures. In addition, minoxidil plus retinol more effectively elevated phosphorylated Erk, phosphorylated Akt levels, and the Bcl-2/Bax ratio than minoxidil alone in DPCs and HaCaT. We found that the significant Hair shaft elongation demonstrated after minoxidil plus retinol treatment would depend on the dual kinetics associated with the activations of Erk- and Akt-dependent pathways and the prevention of apoptosis by increasing the Bcl-2/Bax ratio.
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Human Hair Growth ex vivo is correlated with in vivo Hair Growth: selective categorization of Hair follicles for more reliable Hair follicle organ culture
Archives of Dermatological Research, 2005Co-Authors: Oh Sang Kwon, Hyun Keol Pyo, Kyu Han Kim, Kwang Hyun Cho, Mi Hyang Kim, So Hyun Park, Hee Chul EunAbstract:Of the numerous assays used to assess Hair Growth, Hair follicle organ culture model is one of the most popular and powerful in vitro systems. Changes in Hair Growth are commonly employed as a measurement of follicular activity. Hair cycle stage of mouse vibrissa follicles in vivo is known to determine subsequent Hair Growth and follicle behavior in vitro and it is recommended that follicles be taken at precisely the same cyclic stage. This study was performed to evaluate whether categorization of human Hair follicles by the Growth in vivo could be used to select follicles of the defined anagen stage for more consistent culture. Occipital scalp samples were obtained from three subjects, 2 weeks later after Hair bleaching. Hair Growth and follicle length of isolated anagen VI follicles were measured under a videomicroscope. Follicles were categorized into four groups according to Hair Growth and some were cultured ex vivo for 6 days. Follicles showed considerable variations with respect to Hair Growth and follicle length; however, these two variables were relatively well correlated. Hair Growth in culture was closely related with Hair Growth rate in vivo. Moreover, minoxidil uniquely demonstrated a significant increase of Hair Growth in categorized Hair follicles assumed at a similar early anagen VI stage of Hair cycle. Selection of follicles at a defined stage based on Hair-Growth rate would permit a more reliable outcome in human Hair follicle organ culture.
Ruth Williams - One of the best experts on this subject based on the ideXlab platform.
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Macrophages boost Hair Growth
Journal of Cell Biology, 2007Co-Authors: Ruth WilliamsAbstract:For a healthy head of Hair, activate your macrophages. Besides their role in host defense, these immune cells also promote Hair Growth, according to a report on page [903][1] by Osaka et al. New and rapid Hair Growth is a byproduct of the wound response in mice. The team now finds that this Hair
