title: Evaluation of the in vitro and in vivo genotoxicity of magnolia bark extract.
abstract: Magnolia bark extract (MBE) is an extract of the dried stem, root, or branch bark of magnolia trees that has been used historically in traditional Chinese and Japanese medicines, and more recently as a component of dietary supplements and cosmetic products. To study the genotoxic potential of MBE, a bacterial reverse mutation assay and an in vivo micronucleus test were conducted. Compositional analysis of the test substance revealed that MBE contains 94% magnolol and 1.5% honokiol. MBE exerted no mutagenic activity in various bacterial strains of Salmonella typhimurium and in Escherichia coli WP2 uvrA, either in the absence or presence of metabolic activation at all doses tested. In the micronucleus test, various doses of MBE did not affect the proportions of immature to total erythrocytes, nor did it increase the number of micronuclei in the immature erythrocytes of Swiss albino mice. The results of these studies demonstrate that MBE is not genotoxic under the conditions of the in vitro bacterial reverse mutation assay and the in vivo micronucleus test, and support the safety of MBE for dietary consumption.
authors: Department of Toxicological Safety Assessment, National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
authors: Ning
authors: N
authors: Li
authors: Yan
authors: Y
authors: Song
authors: Wenzhong
authors: W
authors: Zhang
authors: Wei
authors: W
authors: Wang
authors: Junshi
authors: J
authors: Chen
authors: Andrea W
authors: AW
authors: Wong
authors: Ashley
authors: A
authors: Roberts
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000592:standards / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics; D005260:Female; D017705:Lignans / Q000008:administration & dosage / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity; D031566:Magnolia / Q000737:chemistry*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D015162:Micronucleus Tests; D009152:Mutagenicity Tests / Q000379:methods / Q000592:standards; D009154:Mutation; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D015203:Reproducibility of Results; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D001713:Biphenyl Compounds; D003520:Cyclophosphamide; D017705:Lignans; D010936:Plant Extracts; C005498:magnolol; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols