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Research Area
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Description
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Immunology |
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Biological Activity
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Description
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Clemastine Fumarate (Clemastine) is a selective histamine H1 receptor antagonist with IC50 of 3 nM. |
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Targets
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Histamine H1 receptor |
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IC50 |
3 nM [1] |
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In Vitro
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Clemastine Fumarate inhibits histamine induced rise in [Ca2+]i in HL-60 cells with an IC50 of 3 nM as compared with that of chlorpheniramine or diphenhydramine with IC50 values of 20 nM and 100 nM, respectively. [1] At concentrations of ≥25 μM, Clemastine Fumarate significantly blocks NK and ADCC reactions of lymphocytes against the human erythroleukemia cell line K562 and human B-lymphoblast cell line SB, respectively. [2] Clemastine Fumarate inhibits histamine-induced contraction of guinea pig ileum with an IC50 of 231 nM. [3] Clemastine Fumarate potently inhibits the HERG K+ channel in a concentration-dependent manner in HEK 293 cells stably expressing HERG channels with an IC50 of 12 nM, which can be attenuated by the Y652A or F656A mutation of HERG. [4] Clemastine Fumarate significantly potentiates ATP-induced increase in [Ca2+]i in HEKhP2X7 cells not relying on histamine receptor blockage but on sensitizing P2X7 receptor in a concentration-dependent manner with an EC50 of 10 μM, and increases the IL-1β release from LPS-induced human macrophages. [5] |
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In Vivo
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Administration of Clemastine Fumarate (5-20 mg/kg) displays significantly inhibitory effect on simultaneously induced zymosan paw oedema and croton oil ear oedema in rats in a dose-dependent manner, with the inhibition of 53.6% and 46.8%, respectively, at the dose of 20 mg/kg, and with ID50 values of 18.0 mg/kg and 20.5 mg/kg, respectively. [6] Clemastine Fumarate treatment strongly reduces innate immune responses to Listeria monocytogenes in mice by interfering with the extracellular signal-regulated kinase (ERK)-mediated production of proinflammatory cytokines such as TNF-α and IL-6 surprisingly not dependent on blocking the histamine H1 receptor, leading to significantly higher mortality. [7] |
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Clinical Trials
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Currently under Phase III study to evaluate the effectiveness of Clemastine Fumarate 1.0 mg/g + dexamethasone 0.5 mg/g compared to dexchlorpheniramine maleate 10 mg/g in eczema treatment |
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Features
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Protocol
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Kinase Assay
[1]
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| Inhibition of [Ca2+]i |
HL-60 cells are suspended at 1×107 cells/mL in a buffer consisting of 138 mM NaCl, 6 mM KC1, 1 mM MgSO4, 1 mM Na2HPO4, 5 mM NaHCO3, 5.5 mM glucose, and 20 mM HEPES-NaOH, pH 7.4, supplemented with 0.1% (w/v) bovine serum albumin. The dye fura-2/AM is added at a concentration of 4 μM, and cells are incubated for 10 minutes at 37 °C. Thereafter, cells are diluted with the aforementioned buffer to a concentration of 5×106 cells/mL and incubated for 45 minutes at 37 °C. Subsequently, cells are diluted with the aforementioned buffer to a final concentration of 0.5 × 106 cells/mL and centrifuged at 250 g for 10 minutes at 20 °C. Cells are suspended at 1.0 × 106 cells/mL in the aforementioned buffer and kept at 20 °C until measurement. HL-60 cells are used for up to 4 hours after loading with fura-2/AM, and suspended in 2 mL of the aforementioned buffer, using acryl fluorescence cuvettes. HL-60 cells are incubated for 3 minutes at 37 °C, in the presence of 1 mM Ca2+ and various concentrations of Clemastine Fumarate, before the addition of histamine (100 μM). Fluorescence is determined at 37 °C, with constant stirring of the cells at 1×103 rpm, using a Ratio II spectrofluorometer. The basal fluorescence (basal [Ca2+]i) is measured for 1 minute. The basal [Ca2+]i values are subtracted from the corresponding peak [Ca2+]i values, to calculate the increase in [Ca2+]i. The excitation and emission wavelengths are 340 and 500 nm, respectively. The IC50 value is assessed from competitive curve. |
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Animal Study
[6]
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| Animal Models |
Male Wistar rats with paw oedema induced by subplantar injection of zymosan and ear oedema induced by croton oil |
| Formulation |
Dissolved in saline |
| Doses |
5-20 mg/kg |
| Administration |
Intraperitoneally |
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References |
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[1] Seifert R, et al. Mol Pharmacol, 1992, 42(2), 227-234.
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[2] Nair MP, et al. Cell Immunol, 1983, 81(1), 45-60.
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[3] Merlos M, et al. J Pharmacol Exp Ther, 1997, 280(1), 114-121.
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[4] Ridley JM, et al. J Mol Cell Cardiol, 2006, 40(1), 107-118.
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[5] Nörenberg W, et al. J Biol Chem, 2011, 286(13), 11067-11081.
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[6] Blazsó G, et al. Pharmacol Res, 1997, 35(1), 65-71.
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