title: Toxicological and immunomodulatory assessments of botryosphaeran (β-glucan) produced by Botryosphaeria rhodina RCYU 30101.
abstract: Toxicological and immunomodulatory activities of botryosphaeran (BR), a newly emerged β-glucan that comprises a β-(1 → 3) backbone and β-(1 → 6) branched glucose residues were assessed. BR was 1.82 × 10(6) Da (M.W.) estimated by reversely-linear equation constructed by regression of logarithms of standard polysaccharides and their retention times of gel permeation chromatography. Sprague-Dawley rats were daily gavage-administered with BR at doses of 0, 1.25, 12.5, and 125 mg/kg body weight (BW) for 28 d. Serum hematological and biochemical analysis of all treatment were all within normal ranges. Mitogen-stimulated lymphoblastogenesis of spleno-lymphocytes was enhanced by BR at doses of 1.25 and 12.5 mg/kg BW. Through in vitro comparative assessments, RAW 264.7 macrophage (RAW) cells were treated with BR and two commercial β-glucans, zymosan (ZY) and barley β-glucan (GB), to characterize their relative immunomodulatory properties. All three β-glucans stimulated phagocytosis on fluorescence-labeled Escherichia coli. At dose levels from 5 to 200 μg/mL for 24h, nitric oxide produced by BR- and ZY-treated cells were higher than those produced by GB-treated and control groups. BR, ZY but GB also stimulated RAW cells in producing TNF-α. The results demonstrate that BR is toxicologically accepted and features as a potent immunomodulator.
authors.affiliation: Department of Microbiology, Immunology and Biopharmaceticals, National Chiayi University, Chiayi 60004, Taiwan.
authors.forename: Brian Bor-Chun
authors.initials: BB
authors.lastname: Weng
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Lin
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Hu
authors.forename: Ming-Yuan
authors.initials: MY
authors.lastname: Kao
authors.forename: Shih-Hao
authors.initials: SH
authors.lastname: Wang
authors.forename: Dan-Yuan
authors.initials: DY
authors.lastname: Lo
authors.forename: Tzu-Yuan
authors.initials: TY
authors.lastname: Lai
authors.forename: Lou-Sing
authors.initials: LS
authors.lastname: Kan
authors.forename: Robin Yih-Yuan
authors.initials: RY
authors.lastname: Chiou
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001203:Ascomycota / Q000737:chemistry*; D001483:Base Sequence; D002460:Cell Line; D002850:Chromatography, Gel; D017931:DNA Primers; D005936:Glucans / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity*; D051379:Mice; D008970:Molecular Weight; D010587:Phagocytosis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000276:Adjuvants, Immunologic; D017931:DNA Primers; D005936:Glucans; C483238:botryosphaeran