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McCoy J, Goren A, Naccarato T, Kovacevic M, Situm M, Skudar VL, Lotti T. Identification of the sulfotransferase iso-enzyme primarily responsible for the bio-activation of topical minoxidil. J BIOL REG HOMEOS AG 2019; 33:817-819. [PMID: 31184104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pattern hair loss (i.e., androgenetic alopecia) is a common condition afflicting approximately fifty percent of men and women by the age of fifty. Currently, topical minoxidil is the only US FDA approved drug for the treatment of pattern hair loss in men and women.
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Suchonwanit P, Iamsumang W, Rojhirunsakool S. Efficacy of Topical Combination of 0.25% Finasteride and 3% Minoxidil Versus 3% Minoxidil Solution in Female Pattern Hair Loss: A Randomized, Double-Blind, Controlled Study. Am J Clin Dermatol 2019; 20:147-153. [PMID: 30206824 DOI: 10.1007/s40257-018-0387-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The relationship between female pattern hair loss (FPHL) and androgenic hormones is not well established, but some evidence indicates oral finasteride may be efficacious in FPHL. Use of a topical formulation has been proposed to minimize unwanted effects. OBJECTIVES Our objective was to compare the efficacy and safety of topical 0.25% finasteride combined with 3% minoxidil solution and 3% minoxidil solution as monotherapy in the treatment of FPHL. METHODS This was a prospective, randomized, double-blind study in 30 postmenopausal women with FPHL. Each participant was randomized to receive either topical 0.25% finasteride combined with topical 3% minoxidil or topical 3% minoxidil solution as monotherapy for 24 weeks. To determine efficacy, the hair density and diameter was measured and global photographic assessment was conducted at baseline and 8, 16, and 24 weeks. Side effects and serum dihydrotestosterone levels were also evaluated. RESULTS By 24 weeks, hair density and diameter had increased in both groups, and finasteride/minoxidil was significantly superior to minoxidil solution in terms of hair diameter (p = 0.039). No systemic side effects were reported. However, serum dihydrotestosterone levels in the finasteride/minoxidil group significantly decreased from baseline (p = 0.016). CONCLUSION A topical combination of 0.25% finasteride and 3% minoxidil may be a promising option in the treatment of FPHL with an additional benefit of increasing hair diameter. Nevertheless, as it may be absorbed percutaneously, it should be reserved for postmenopausal women. TRIAL REGISTRATION clinicaltrials.in.th; identifier TCTR20160912002.
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Knutsen RH, Beeman SC, Broekelmann TJ, Liu D, Tsang KM, Kovacs A, Ye L, Danback JR, Watson A, Wardlaw A, Wagenseil JE, Garbow JR, Shoykhet M, Kozel BA. Minoxidil improves vascular compliance, restores cerebral blood flow, and alters extracellular matrix gene expression in a model of chronic vascular stiffness. Am J Physiol Heart Circ Physiol 2018; 315:H18-H32. [PMID: 29498532 PMCID: PMC6087770 DOI: 10.1152/ajpheart.00683.2017] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 01/27/2023]
Abstract
Increased vascular stiffness correlates with a higher risk of cardiovascular complications in aging adults. Elastin (ELN) insufficiency, as observed in patients with Williams-Beuren syndrome or with familial supravalvular aortic stenosis, also increases vascular stiffness and leads to arterial narrowing. We used Eln+/- mice to test the hypothesis that pathologically increased vascular stiffness with concomitant arterial narrowing leads to decreased blood flow to end organs such as the brain. We also hypothesized that drugs that remodel arteries and increase lumen diameter would improve flow. To test these hypotheses, we compared carotid blood flow using ultrasound and cerebral blood flow using MRI-based arterial spin labeling in wild-type (WT) and Eln+/- mice. We then studied how minoxidil, an ATP-sensitive K+ channel opener and vasodilator, affects vessel mechanics, blood flow, and gene expression. Both carotid and cerebral blood flows were lower in Eln+/- mice than in WT mice. Treatment of Eln+/- mice with minoxidil lowered blood pressure and reduced functional arterial stiffness to WT levels. Minoxidil also improved arterial diameter and restored carotid and cerebral blood flows in Eln+/- mice. The beneficial effects persisted for weeks after drug removal. RNA-Seq analysis revealed differential expression of 127 extracellular matrix-related genes among the treatment groups. These results indicate that ELN insufficiency impairs end-organ perfusion, which may contribute to the increased cardiovascular risk. Minoxidil, despite lowering blood pressure, improves end-organ perfusion. Changes in matrix gene expression and persistence of treatment effects after drug withdrawal suggest arterial remodeling. Such remodeling may benefit patients with genetic or age-dependent ELN insufficiency. NEW & NOTEWORTHY Our work with a model of chronic vascular stiffness, the elastin ( Eln)+/- mouse, shows reduced brain perfusion as measured by carotid ultrasound and MRI arterial spin labeling. Vessel caliber, functional stiffness, and blood flow improved with minoxidil. The ATP-sensitive K+ channel opener increased Eln gene expression and altered 126 other matrix-associated genes.
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Pekmezci E, Türkoğlu M. Minoxidil Acts as an Antiandrogen: A Study of 5α-reductase Type 2 Gene Expression in a Human Keratinocyte Cell Line. ACTA DERMATOVENEROLOGICA CROATICA : ADC 2017; 25:271-275. [PMID: 30064598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Although more than three decades have passed since the first use of minoxidil in androgenetic alopecia (AGA), its mechanisms of action have still not been comprehensively understood. 5α-reductase (5α-R) has an active role as the predominant enzyme in both AGA and female pattern hair loss (FPHL), which are also the main therapeutic indications of topical minoxidil. But there is insufficient literature data regarding the interaction of minoxidil and the enzyme 5α-R. Herein, we studied the in vitro expression levels of 5α-R type 2 (5α-R2) in a minoxidil-treated human keratinocyte cell line (HaCaT) in order to elucidate the relation of these two parameters. Cell proliferation assay was performed by a XTT reagent (a yellow tetrazolium salt). After determination of non-cytotoxic concentration, HaCaT cells were treated with minoxidil. Ribonucleic acid (RNA) isolations were carried out from both non-treated and treated cell groups using a TRI reagent (an RNA, DNA, and protein isolation reagent). Gene expressions of 5α-R2 as study material and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the control were determined by real time-quantitative polymerase chain reaction (RT-qPCR) analysis. Results were represented as 5α-R2 / GAPDH fold change. Minoxidil treatment resulted in a 0.22 fold change for 5α-R2 (p < 0.0001). This antiandrogenic effect of minoxidil, shown by significant downregulation of 5α-R2 gene expression in HaCaT cells, may be one of its mechanisms of action in alopecia.
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Zhang L, Li MM, Corcoran M, Zhang S, Cooper GJS. Essential roles of insulin, AMPK signaling and lysyl and prolyl hydroxylases in the biosynthesis and multimerization of adiponectin. Mol Cell Endocrinol 2015; 399:164-77. [PMID: 25240468 DOI: 10.1016/j.mce.2014.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 12/22/2022]
Abstract
Post-translational modifications (PTMs) of the adiponectin molecule are essential for its full bioactivity, and defects in PTMs leading to its defective production and multimerization have been linked to the mechanisms of insulin resistance, obesity, and type-2 diabetes. Here we observed that, in differentiated 3T3-L1 adipocytes, decreased insulin signaling caused by blocking of insulin receptors (InsR) with an anti-InsR blocking antibody, increased rates of adiponectin secretion, whereas concomitant elevations in insulin levels counteracted this effect. Adenosine monophosphate-activated protein kinase (AMPK) signaling regulated adiponectin production by modulating the expression of adiponectin receptors, the secretion of adiponectin, and eventually the expression of adiponectin itself. We found that lysyl hydroxylases (LHs) and prolyl hydroxylases (PHs) were expressed in white-adipose tissue of ob/ob mice, wherein LH3 levels were increased compared with controls. In differentiated 3T3-L1 adipocytes, both non-specific inhibition of LHs and PHs by dipyridyl, and specific inhibition of LHs by minoxidil and of P4H with ethyl-3,4-dihydroxybenzoate, caused significant suppression of adiponectin production, more particularly of the higher-order isoforms. Transient gene knock-down of LH3 (Plod3) caused a suppressive effect, especially on the high molecular-weight (HMW) isoforms. These data indicate that PHs and LHs are both required for physiological adiponectin production and in particular are essential for the formation/secretion of the HMW isoforms.
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Choi JS, Jung SK, Jeon MH, Moon JN, Moon WS, Ji YH, Choi IS, Wook Son S. Effects of Lycopersicon esculentum extract on hair growth and alopecia prevention. JOURNAL OF COSMETIC SCIENCE 2013; 64:429-443. [PMID: 24397881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Accepted: 05/05/2013] [Indexed: 06/03/2023]
Abstract
To evaluate the potential hair growth-promoting activity and the expression of cell growth factors of Lycopersicon esculentum extracts, each 3% (w/w) of ethyl acetate extract (EAE), and supercritical CO2 extract (SCE) of L. esculentum and isolated lycopene Tween 80 solution (LTS) and test hair tonic (THT) containing LTS were applied on the dorsal skin of C57BL/6 mice, once a day for 4 weeks. At week 4, LTS and THT exhibited hair growth-promoting potential similar to that of 3% minoxidil as a positive control (PC). Further, in the LTS group, a significant increase of mRNA expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor, and insulin-like growth factor-1 (IGF-1) was observed than PC, as well as the negative control (NC). In the THT group, increases in IGF-1 and decrease in VEGF and transforming growth factor-β expression were significant over the NC. In a histological examination in the THT group, the induction of anagen stage of hair follicles was faster than that of NC. In the Draize skin irritation study for THT, no observable edema or erythema was observed on all four sectors in the back skin after exposure for 24 or 72 h for any rabbit. Therefore, this study provides reasonable evidence that L. esculentum extracts promote hair growth and suggests that applications could be found in hair loss treatments without skin irritation at moderate doses.
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Gümüş N, Odemiş Y, Yılmaz S, Tuncer E. Effect of topically applied minoxidil on the survival of rat dorsal skin flap. Aesthetic Plast Surg 2012; 36:1382-6. [PMID: 22955791 DOI: 10.1007/s00266-012-9966-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 07/09/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Flap necrosis still is a challenging problem in reconstructive surgery that results in irreversible tissue loss. This study evaluated the effect of topically applied minoxidil on angiogenesis and survival of a caudally based dorsal rat skin flap. METHODS For this study, 24 male Wistar rats were randomly divided into three groups of eight each. A caudally based dorsal skin flap with the dimensions of 9 × 3 cm was raised. After elevation of the flaps, they were sutured back into their initial positions. In group 1 (control group), 1 ml of isotonic saline was applied topically to the flaps of all the animals for 14 days. In group 2, minoxidil solution was spread uniformly over the flap surface for 7 days after the flap elevation. In group 3, minoxidil solution was applied topically to the flap surface during a 14-day period. On day 7 after the flap elevation, the rats were killed. The average area of flap survival was determined for each rat. Subdermal vascular architecture and angiogenesis were evaluated under a light microscope after two full-thickness skin biopsy specimens had been obtained from the midline of the flaps. RESULTS The lowest flap survival rate was observed in group 1, and no difference was observed between groups 1 and 2. Compared with groups 1 and 2, group 3 had a significantly increased percentage of flap survival (P < 0.05). Intense and moderate angiogenesis also was observed respectively at the proximal and distal areas of the flaps in group 3. CONCLUSIONS The results of this experiment seem to show that the early effect of minoxidil is vasodilation and that prolonged use before flap elevation leads to angiogenesis, increasing flap viability. LEVEL OF EVIDENCE III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Sitdikova GF, Khaertdinov NN, Zefirov AL. Role of calcium and potassium channels in effects of hydrogen sulfide on frog myocardial contractility. Bull Exp Biol Med 2012; 151:163-6. [PMID: 22238741 DOI: 10.1007/s10517-011-1280-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The effects of sodium hydrosulfide NaHS, a donor of hydrogen sulfide H2S, on the force of muscle contraction were examined on isolated myocardial strips from frog ventricles. NaHS decreased the amplitude of muscle contractions in a dose-dependent manner under normal conditions and during inhibition of Ca channels with nifedipine. In contrast, under conditions of blockade of ATP-dependent potassium channels with glibenclamide, NaHS exerted a positive inotropic effect from the first minute of application. Neither blockade, nor activation of ATP-dependent K-channels with glibenclamide modulated the negative inotropic effect of NaHS. Inhibition of K-channels with tetraethylammonium (TEA) (3, 5, 10 mM) or 4-aminopyridine increased the amplitude of myocardial contractions. Preliminary application of 4-aminopyridine or TEA (3 mM) did not eliminate NaHS-induced negative inotropic effect, although higher TEA concentrations (5 or 10 mM) prevented it. The data indicate that the targets of H(2)S in frog myocardium are ATP-dependent, Ca-activated, and voltage-dependent K-channels.
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Lee SH, Yoon J, Shin SH, Zahoor M, Kim HJ, Park PJ, Park WS, Min DS, Kim HY, Choi KY. Valproic acid induces hair regeneration in murine model and activates alkaline phosphatase activity in human dermal papilla cells. PLoS One 2012; 7:e34152. [PMID: 22506014 PMCID: PMC3323655 DOI: 10.1371/journal.pone.0034152] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 02/23/2012] [Indexed: 11/25/2022] Open
Abstract
Background Alopecia is the common hair loss problem that can affect many people. However, current therapies for treatment of alopecia are limited by low efficacy and potentially undesirable side effects. We have identified a new function for valproic acid (VPA), a GSK3β inhibitor that activates the Wnt/β-catenin pathway, to promote hair re-growth in vitro and in vivo. Methodology/ Principal Findings Topical application of VPA to male C3H mice critically stimulated hair re-growth and induced terminally differentiated epidermal markers such as filaggrin and loricrin, and the dermal papilla marker alkaline phosphatase (ALP). VPA induced ALP in human dermal papilla cells by up-regulating the Wnt/β-catenin pathway, whereas minoxidil (MNX), a drug commonly used to treat alopecia, did not significantly affect the Wnt/β-catenin pathway. VPA analogs and other GSK3β inhibitors that activate the Wnt/β-catenin pathway such as 4-phenyl butyric acid, LiCl, and BeCl2 also exhibited hair growth-promoting activities in vivo. Importantly, VPA, but not MNX, successfully stimulate hair growth in the wounds of C3H mice. Conclusions/ Significance Our findings indicate that small molecules that activate the Wnt/β-catenin pathway, such as VPA, can potentially be developed as drugs to stimulate hair re-growth.
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McDonough PH, Schwartz RA. Adolescent androgenic alopecia. Cutis 2011; 88:165-168. [PMID: 22106721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Adolescent androgenic alopecia is pattern hair loss occurring in boys and girls younger than 18 years, whereas early-onset androgenic alopecia refers to pattern hair loss before 35 years of age. A number of studies published in the last decade have helped to elucidate the prevalence of adolescent androgenic alopecia, have clarified the genetic as well as physiologic mechanisms underlying hair loss, and have revealed the associated psychologic and systemic morbidities. This article provides an overview of the pathophysiology, diagnosis, and treatment of adolescent androgenic alopecia.
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Slim HB, Black HR, Thompson PD. Older blood pressure medications-do they still have a place? Am J Cardiol 2011; 108:308-16. [PMID: 21550576 DOI: 10.1016/j.amjcard.2011.03.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/11/2011] [Accepted: 03/11/2011] [Indexed: 01/13/2023]
Abstract
Hypertension is a major risk factor for cardiovascular disease, but control of hypertension remains inadequate, often because of poor patient adherence to prescribed medical regimens that are viewed as poorly tolerated and expensive. Physicians have largely stopped using some older blood pressure medications in favor of newer agents, mostly because of a presumed more favorable side effect profile. The investigators reviewed the pharmacologic properties and the evidence supporting the effectiveness and tolerability of several older blood pressure drugs: sympatholytic agents such as reserpine, methyldopa, and clonidine; diuretics such as chlorthalidone, ethacrynic acid and spironolactone; the vasodilators hydralazine and minoxidil; and others. In conclusion, some of these drugs are well studied and represent alternatives for patients who cannot afford or tolerate newer medications.
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Khanna N, Malhotra RS, Mehta AK, Garg GR, Halder S, Sharma KK. Potassium channel openers exhibit cross-tolerance with morphine in two experimental models of pain. W INDIAN MED J 2010; 59:473-478. [PMID: 21473392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE The study was performed to assess the effect of potassium channel openers on morphine tolerance and vice-versa. METHODS Swiss albino mice of either gender weighing between 25-30 g were used for the study The study assesses the effect of potassium channel openers (cromakalim, diazoxide and minoxidil) on morphine tolerance and vice-versa, using formalin and tail-flick tests. RESULTS The antinociceptive effect of cromakalim and minoxidil was significantly reduced when administered to morphine-tolerant mice, in both the behavioural tests. However reduced analgesic effect of diazoxide was observed on morphine-tolerance in the formalin test but not in the tail-flick test. Tolerance was observed when morphine was administered to animals chronically treated with any of the potassium channel openers. The same effect was observed when morphine was injected into a group treated with a combination of morphine and any of the potassium channel openers. CONCLUSIONS This study, therefore, suggests that both morphine and potassium channel openers are cross-tolerant. However such interaction occurs at the level of potassium channels rather than at the level of receptors.
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Datta K, Singh AT, Mukherjee A, Bhat B, Ramesh B, Burman AC. Eclipta alba extract with potential for hair growth promoting activity. JOURNAL OF ETHNOPHARMACOLOGY 2009; 124:450-456. [PMID: 19481595 DOI: 10.1016/j.jep.2009.05.023] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 05/20/2009] [Accepted: 05/21/2009] [Indexed: 05/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Eclipta alba is traditionally known to potentiate hair growth promotion. AIM OF THE STUDY The study was aimed to investigate the efficacy of methanol extract of Eclipta alba as hair growth promoter. MATERIALS AND METHODS Pigmented C57/BL6 mice, preselected for their telogen phase of hair growth were used. In these species, the truncal epidermis lacks melanin-producing melanocytes and melanin production is strictly coupled to anagen phase of hair growth. The extract was applied topically to assess telogen to anagen transition. Immunohistochemical investigation was performed to analyze antigen specificity. Animals in anagen phase of hair growth were positive for FGF-7 and Shh and negative for BMP4, whereas the animals in telogen phase were positive only for BMP4 antigen. RESULTS The methanol extract of whole plant when tested for hair growth promoting potential, exhibited dose dependent activity in C57BL6 mice. The activity was assessed by studying the melanogenesis in resected skin, follicle count in the subcutis, skin thickness and surrogate markers in vehicle control and extract treated animals. CONCLUSION These findings suggest that methanol extract of Eclipta alba may have potential as a hair growth promoter.
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Saar BG, Holtom GR, Freudiger CW, Ackermann C, Hill W, Xie XS. Intracavity wavelength modulation of an optical parametric oscillator for coherent Raman microscopy. OPTICS EXPRESS 2009; 17:12532-9. [PMID: 19654655 DOI: 10.1364/oe.17.012532] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We present a novel intracavity frequency modulation scheme in a tunable, picosecond optical parametric oscillator (OPO). The OPO signal wavelength can be modulated with a depth of more than 10 nm at a rate of 38 MHz (one half its repetition rate). We discuss the design and construction of the light source and its application to the recently-developed frequency modulation coherent anti-Stokes Raman scattering (FM-CARS) and stimulated Raman scattering (SRS) techniques. The new light source allows for real time subtraction of the interfering background signal in coherent Raman imaging, yielding images with purely chemical contrast.
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Rizzioli E, Incasa E, Gamberini S, Manfredini R. Management of intradialytic hypertension: old problem, old drug? Intern Emerg Med 2009; 4:271-2. [PMID: 19367467 DOI: 10.1007/s11739-009-0249-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022]
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Li YC, Chiang CW, Yeh HC, Hsu PY, Whitby FG, Wang LH, Chan NL. Structures of prostacyclin synthase and its complexes with substrate analog and inhibitor reveal a ligand-specific heme conformation change. J Biol Chem 2008; 283:2917-26. [PMID: 18032380 PMCID: PMC2293295 DOI: 10.1074/jbc.m707470200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Prostacyclin synthase (PGIS) is a cytochrome P450 (P450) enzyme that catalyzes production of prostacyclin from prostaglandin H(2). PGIS is unusual in that it catalyzes an isomerization rather than a monooxygenation, which is typical of P450 enzymes. To understand the structural basis for prostacyclin biosynthesis in greater detail, we have determined the crystal structures of ligand-free, inhibitor (minoxidil)-bound and substrate analog U51605-bound PGIS. These structures demonstrate a stereo-specific substrate binding and suggest features of the enzyme that facilitate isomerization. Unlike most microsomal P450s, where large substrate-induced conformational changes take place at the distal side of the heme, conformational changes in PGIS are observed at the proximal side and in the heme itself. The conserved and extensive heme propionate-protein interactions seen in all other P450s, which are largely absent in the ligand-free PGIS, are recovered upon U51605 binding accompanied by water exclusion from the active site. In contrast, when minoxidil binds, the propionate-protein interactions are not recovered and water molecules are largely retained. These findings suggest that PGIS represents a divergent evolution of the P450 family, in which a heme barrier has evolved to ensure strict binding specificity for prostaglandin H(2), leading to a radical-mediated isomerization with high product fidelity. The U51605-bound structure also provides a view of the substrate entrance and product exit channels.
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Sandhiya S, Dkhar SA, Krishna PRM, Ramaswamy S. Role of ion channel modifiers in reversal of morphine-induced gastrointestinal inertia by prokinetic agents in mice. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 2008; 46:60-65. [PMID: 18697573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Prokinetic drugs like mosapride, domperidone etc, are used to treat gastrointestinal delay. Though the receptor-mediated actions of these agents have been studied, involvement of ion channels in reversing morphine-induced gastrointestinal inertia by prokinetic agents has not been explored. Charcoal meal test was used to measure small intestinal transit (SIT) in adult male Swiss albino mice. Animals were given ion channel modifiers and prokinetic drugs intragastrically. Reversal of morphine-induced gastrointestinal delay by mosapride was decreased significantly by CaCl2, minoxidil and glibenclamide. Similarly, domperidone's effect on morphine was decreased by CaCl2, nifedipine, minoxidil and glibenclamide significantly. The results reveal that ion channel modifiers counteract the prokinetic effects of mosapride or domperidone.
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Roy RK, Thakur M, Dixit VK. Development and evaluation of polyherbal formulation for hair growth?promoting activity. J Cosmet Dermatol 2007; 6:108-12. [PMID: 17524127 DOI: 10.1111/j.1473-2165.2007.00305.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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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Taylor GL, Patel B, Sullivan AT. Evaluation of blood flow parameters in addition to blood pressure and electrocardiogram in the conscious telemetered beagle dog. J Pharmacol Toxicol Methods 2007; 56:212-7. [PMID: 17582788 DOI: 10.1016/j.vascn.2007.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 04/16/2007] [Indexed: 11/21/2022]
Abstract
INTRODUCTION The objective of this study was to evaluate a model for measuring blood flow parameters in addition to blood pressure, heart rate and electrocardiogram (ECG) in conscious telemetered restrained and unrestrained beagle dogs. METHODS Male beagle dogs were instrumented with fully implantable ITS radio telemetry devices for the measurement of blood pressure and ECG. In addition, the dogs were instrumented with a probe around the pulmonary artery for the measurement of blood flow by ultrasound. Dobutamine at 5, 10 and 20 mug/kg/min, given intravenously to sling restrained animals (n=4), and minoxidil at 2 mg/kg, given orally to unrestrained animals (n=4), were selected as test compounds known to cause changes in the cardiovascular parameters of interest in this work. RESULTS Dobutamine produced a small increase in mean (9%) and systolic blood pressure (5%), and an increase in pulse pressure (37%) and heart rate (30%). The additional blood flow parameters showed that dobutamine also increased stroke volume (21%) and cardiac output (58%) and reduced total peripheral resistance (52%). Minoxidil treatment resulted in a prolonged reduction in mean, systolic and diastolic blood pressure (up to 24%). Additionally, a prolonged increase in heart rate (169%) and cardiac output (120%) were observed along with a reduction in total peripheral resistance (62%). The effects of both compounds were consistent with their known pharmacology. DISCUSSION The results show that measurement of blood flow parameters can be successfully added to the standard telemetered cardiovascular dog model to provide valuable additional information on the effects of compounds on the cardiovascular system.
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Tian T, Fan WX, Dai YQ, Liu LP. [Effect of tacrolimus on the growth cycle of murine hair follicles]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2007; 29:209-12. [PMID: 17536270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To explore the effect of tacrolimus on murine hair follicle cycle. METHOD Hematoxylin-eosin dyeing and reverse transcription-polymerase chain raction techniques were used. RESULTS Five days after depilation, the hair follicles in both the tacrolimus group and the minoxidil group was in anagen V, while that in the vaseline group was in anagen III. vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were detected in back skin in both the tacrolimus group and the minoxidil group, but not in the vaseline group. CONCLUSION Tacrolimus can promote the growth of hair by stimulating the hair follicle to enter anagen V in mice, which may be explained by the effects of VEGF and HGF.
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Yoo HG, Chang IY, Pyo HK, Kang YJ, Lee SH, Kwon OS, Cho KH, Eun HC, Kim KH. The additive effects of minoxidil and retinol on human hair growth in vitro. Biol Pharm Bull 2007; 30:21-6. [PMID: 17202653 DOI: 10.1248/bpb.30.21] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
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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Wessler I, Herschel S, Bittinger F, Kirkpatrick CJ. Release of non-neuronal acetylcholine from the isolated human placenta is affected by antidepressants. Life Sci 2007; 80:2210-3. [PMID: 17275854 DOI: 10.1016/j.lfs.2007.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 12/07/2006] [Accepted: 01/06/2007] [Indexed: 11/22/2022]
Abstract
Non-neuronal acetylcholine (ACh) is released from the human placenta into the extracellular space via organic cation transporters (OCTs). The present experiments investigated whether ACh release from epithelial cells is affected by drugs which are substrates of OCTs. The antidepressant drugs amitriptyline and doxepine were tested as both substances are not approved for pregnant women but frequently used. Release of ACh was measured in 10 min intervals over a period of 100 min. Test substances were added from t=50 min of incubation onwards. The effect was calculated by comparing the ACh release of the last three samples (t=70-100 min; B2) with that immediately before the application of the test substances (t=20-50 min; B1). The baseline ACh release amounted to 2.07+/-0.17 nmol/10 min (n=29; villus). Under control conditions a B2/B1 ratio of 0.78+/-0.02 was obtained. The following B2/B1 ratios were found, when therapeutic drugs were added: 0.54+/-0.04 (n=7; P<0.05) in the presence of 10 microM amitriptyline; 0.44+/-0.04 (10; P<0.01) in the presence of 10 microM doxepin; 0.73+/-0.04 (13) in the presence of 10 microM metformin; 0.76+/-0.06 (7) in the presence of 10 microM minoxidil; 0.63+/-0.03 (10) in the presence of 1 microM theophylline. The results demonstrate that antidepressants reduce the release of non-neuronal ACh at least in the human placenta, most likely by intracellular substrate competition at the polyspecific organic cation transporters (OCTs) but only at concentrations roughly 30-fold above the therapeutic range. Theophylline may also interfere with the release of non-neuronal ACh.
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Gibson G, Ramstad T, Mills KA, Dunn MJ. A method for the determination of minoxidil in hair-regrowth formulations by micellar electrokinetic capillary chromatography. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2005; 60:847-53. [PMID: 16043173 DOI: 10.1016/j.farmac.2005.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Accepted: 06/10/2005] [Indexed: 05/03/2023]
Abstract
A method based on micellar electrokinetic capillary chromatography (MEKC) was developed for determination of minoxidil in Rogaine and competing products. The original intent of the work was to offer an orthogonal means to HPLC for testing illicit imitations of Rogaine. However, because the patent has since expired, we offer the procedure as a confirmatory measure to HPLC for assay of generic minoxidil products. The MEKC procedure complements an earlier method based on free solution capillary electrophoresis (FSCE), designed to the same end. Validation was carried out on both a Dionex CES-1, which utilizes gravity injection, and a PE-ABI 270HT, which employs vacuum injection. The procedure was validated for both active pharmaceutical ingredient and for minoxidil solutions. The run buffer is pH 7.0, 20 mM sodium phosphate, 20 mM sodium dodecyl sulfate, with 10% isopropanol; the internal standard is dl-tryptophan. The method bears the attributes of simplicity, ease of use, and short analysis time (12 min). It is selective with respect to known process and degradation impurities. High efficiency was achieved on the CES-1, with a plate count exceeding 200,000 for minoxidil at an elution time of 9 min. Although slight differences in performance were noted across the two instruments, results on both were in conformance with modern day validation expectations. Comparison of MEKC with HPLC resulted in slightly higher values for the former, but all results met registration specifications and internal targets.
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Tyagi MG, Velu ST, Vikram GS. Renal humoral modulation of skeletal muscle tone in mice: implications for 'the pulmonary-renal cascade'. INDIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2005; 49:403-10. [PMID: 16579393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The pulmonary-renal cascade may regulate the respiration and skeletal muscle contractility. To evaluate this working hypothetical model, we conducted experiments to ascertain the skeletal muscle tone of the Swiss mice (20-35 g). The animals were evaluated for their skeletal muscle tone via several techniques i.e. inclined plane test, grip strength test and swim test. Groups of mice (n=6) were pre-treated with mefenamic acid (60 mg/kg, i.p), carbenoxolone (100 mg/kg i.p) or vehicle only 15 minutes before the treatment with heparin (500 U/kg, i.v), urokinase (5500 U/kg, i.v) and erythropoietin (150 U/kg, i.v). Heparin potentiated the loss of skeletal muscle tone induced by mefenamic acid and carbenoxolone while urokinase & erythropoietin significantly enhanced the skeletal muscle tone as evaluated by all or one of the tests. Other groups of mice (n=6) were pretreated with mefenamic acid (1 mg i.c.v), carbenoxolone (160 microg i.c.v) or minoxidil (30 microg i.c.v) and the effects of heparin & urokinase and erythropoietin on skeletal muscle tone were evaluated. To study the effects of heparin and urokinase on nerve regeneration, two groups of mice underwent a sham and sciatic nerve crush procedure. The mice treated with urokinase recovered much faster as compared to those treated with heparin or saline. These experimental results suggest that gap junction blockers and potassium channel openers interact with heparin, urokinase and erythropoietin to control the skeletal muscle tone.
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Zuurmond AM, van der Slot-Verhoeven AJ, van Dura EA, De Groot J, Bank RA. Minoxidil exerts different inhibitory effects on gene expression of lysyl hydroxylase 1, 2, and 3: implications for collagen cross-linking and treatment of fibrosis. Matrix Biol 2005; 24:261-70. [PMID: 15908192 DOI: 10.1016/j.matbio.2005.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2004] [Revised: 04/06/2005] [Accepted: 04/06/2005] [Indexed: 10/25/2022]
Abstract
Collagen deposits in fibrotic lesions often display elevated levels of hydroxyallysine (pyridinoline) cross-links. The relation between the occurrence of pyridinoline cross-links and the irreversibility of fibrosis suggests that these cross-links contribute to the aberrant accumulation of collagen. Based on its inhibitory effect on lysyl hydroxylase activity minoxidil has been postulated to possess anti-fibrotic properties by limiting the hydroxylysine supply for hydroxyallysine cross-linking. However, to interfere with hydroxyallysine cross-linking specifically lysyl hydroxylation of the collagen telopeptide should be inhibited, a reaction predominantly catalysed by lysyl hydroxylase (LH) 2b. In this study, we demonstrate that minoxidil treatment of cultured fibroblasts reduces LH1>>LH2b>LH3 mRNA levels dose-and time-dependently, but has essentially no effect on the total number of pyridinoline cross-links in the collagen matrix. Still the collagen produced in the presence of minoxidil displays some remarkable features: hydroxylation of triple helical lysine residues is reduced to 50% and lysylpyridinoline cross-linking is increased at the expense of hydroxylysylpyridinoline cross-linking. These observations can be explained by our finding that LH1 mRNA levels are the most sensitive to minoxidil treatment, corroborating that LH1 has a preference for triple helical lysine residues as substrate. In addition, the non-proportional increase in cross-links (20-fold) with respect to the decrease in lysyl hydroxylation state of the triple helix (2-fold) even suggests that LH1 preferentially hydroxylates triple helical lysine residues at the cross-link positions. We conclude that minoxidil is unlikely to serve as an anti-fibroticum, but confers features to the collagen matrix, which provide insight into the substrate specificity of LH1.
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