title: Inhibitory effect of fulvic acid extracted from Canadian sphagnum peat on chemical mediator release by RBL-2H3 and KU812 cells.
abstract: Fulvic acid (FA) was extracted and purified from Canadian Sphagnum peat (CP-FA) and characterized by using an element analysis meter, Fourier transform infrared (FT-IR) spectroscopy, electron spin resonance (ESR) spectroscopy, and (13)C-nuclear magnetic resonance ((13)C-NMR) spectroscopy. To investigate the antiallergic effect of CP-FA, we incubated rat basophilic leukemia (RBL-2H3) cells with 0.001-10.0 microg/ml of CP-FA and determined the beta-hexosaminidase release inhibition at different response stages. The intracellular calcium [Ca(2+)](i) level was also determined by using Fluo 3-AM, a calcium-specific fluorescent probe, and the cytotoxicity of CP-FA was determined by the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. The results revealed that RBL-2H3 cells incubated for 48 h with 0.001-10.0 microg/ml of CP-FA did not show any decreased viability. CP-FA inhibited the beta-hexosaminidase release by IgE-sensitized, antigen-stimulated RBL-2H3 cells at the antigen-antibody binding stage and the antibody-receptor binding stage. CP-FA also inhibited histamine release from A23187 plus PMA- or compound 48/80-stimulated KU812 cells. Furthermore, there was a decrease in the intracellular [Ca(2+)](i) level in IgE-sensitized cells incubated with CP-FA and stimulated with antigen. Our results show that CP-FA may be useful for the treatment or prevention of allergic diseases.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Parida
authors.initials: P
authors.lastname: Yamada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Isoda
authors.forename: Jun Kyu
authors.initials: JK
authors.lastname: Han
authors.forename: Terence P N
authors.initials: TP
authors.lastname: Talorete
authors.forename: Yukuo
authors.initials: Y
authors.lastname: Abe
mesh_terms: D000818:Animals; D018926:Anti-Allergic Agents / Q000494:pharmacology*; D000936:Antigen-Antibody Complex / Q000276:immunology; D000941:Antigens / Q000276:immunology; D001491:Basophils / Q000378:metabolism*; D001578:Benzopyrans / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005456:Fluorescent Dyes; D005562:Formazans / Q000378:metabolism; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D015471:Leukemia, Basophilic, Acute; D007942:Leukemia, Experimental; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017550:Spectroscopy, Fourier Transform Infrared; D044003:Sphagnopsida / Q000737:chemistry*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013778:Tetrazolium Salts / Q000378:metabolism; D001619:beta-N-Acetylhexosaminidases / Q000037:antagonists & inhibitors; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D018926:Anti-Allergic Agents; D000936:Antigen-Antibody Complex; D000941:Antigens; D001578:Benzopyrans; D005456:Fluorescent Dyes; D005562:Formazans; D007476:Ionophores; D010936:Plant Extracts; D013778:Tetrazolium Salts; C079782:MTT formazan; D007073:Immunoglobulin E; D000001:Calcimycin; D003189:p-Methoxy-N-methylphenethylamine; D001619:beta-N-Acetylhexosaminidases; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; C005023:fulvic acid