title: Effects of the extract of the bark of Magnolia obovata and its biphenolic constituents magnolol and honokiol on histamine release from peritoneal mast cells in rats.
abstract: We have previously reported that saiboku-to, an Oriental herbal remedy composed of a mixture of 10 different herbal extracts, possesses anti-histamine release effect on mast cells in rats. This effect may be due mainly to the extract of the bark of Magnolia obovata (M. obovata), a constituent herb of saiboku-to. In the present study, it was demonstrated that the bark extract inhibited compound 48/80 (C48/80)-induced histamine release from mast cells in a concentration-dependent manner (50 % inhibitory concentration, IC(50) = 56.98 microg/ml). Furthermore, the inhibitory activity was found in the methanol fraction, but not in water and 50 % aqueous methanol fractions derived from the bark extract. Magnolol and honokiol isolated from the methanol fraction inhibited C48/80-induced histamine release from mast cells. The potency of magnolol (IC(50) = 1.04 microg/ml) was greater than that of honokiol (IC(50) = 2.77 microg/ml). Furthermore, the actual amount of magnolol (49.76 +/- 1.14 mg) contained in the bark of M. obovata (5 g) was greater than that (8.58 +/- 0.19 mg) of honokiol. Taken together, the present results suggest that magnolol may be responsible for the biological efficacy of the bark extract of M. obovata.
authors.affiliation: Department of Neuropsychopharmacology (Tsumura), Gunma University School of Medicine, Maebashi, Gunma, Japan. ikarashi_yasushi@mail.tsumura.co.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Ikarashi
authors.forename: M
authors.initials: M
authors.lastname: Yuzurihara
authors.forename: I
authors.initials: I
authors.lastname: Sakakibara
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
authors.forename: N
authors.initials: N
authors.lastname: Hattori
authors.forename: Y
authors.initials: Y
authors.lastname: Maruyama
mesh_terms: D000818:Animals; D001713:Biphenyl Compounds / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use; D006634:Histamine H1 Antagonists / Q000627:therapeutic use; D006636:Histamine Release / Q000187:drug effects*; D017705:Lignans; D029562:Magnoliaceae; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D020835:Medicine, Kampo; D010529:Peritoneal Cavity / Q000166:cytology; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D001713:Biphenyl Compounds; D004365:Drugs, Chinese Herbal; D006634:Histamine H1 Antagonists; D017705:Lignans; D010936:Plant Extracts; D003189:p-Methoxy-N-methylphenethylamine; C045086:saiboku-to; C005498:magnolol; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols