title: Bisabololoxide A, one of the main constituents in German chamomile extract, induces apoptosis in rat thymocytes.
abstract: German chamomile (Matricaria recutita L.), one of the popular ingredients in herbal teas, has been traditionally used for medicinal purposes. Bisabololoxide A (BSBO) is one of the main constituents in this herb. BSBO is supposed to be principle in some bioactivities of German chamomile such as anti-inflammatory, gastrointestinal, and antipruritic actions. Although the use of German chamomile has spread, the information related to toxicity of BSBO is very limited. In present study, the cytotoxic effect of micromolar BSBO was cytometrically examined on rat thymocytes by using appropriate fluorescent dyes. When the cells were incubated with BSBO for 24 h, BSBO at concentrations of 30 microM or more significantly increased populations of dead cells, shrunken cells, and cells with phosphatidylserine exposed on membrane surface. Both cell shrinkage and externalization of membrane phosphatidylserine are general features in an early stage of apoptosis. In addition, BSBO significantly increased population of cells containing hypodiploid DNA, and the increase was completely attenuated by Z-VAD-FMK, a pan-inhibitor for caspases, indicating an involvement of caspase activation. Thus, it is likely that the type of cell death induced by BSBO is apoptosis. The significant changes in cellular parameters of rat thymocytes by BSBO were not observed when the concentration was 10 microM or less. Furthermore, the short incubation (3 h) of cells even with 30-100 microM BSBO did not significantly affect the cells. Therefore, it may be suggested that BSBO is practically safe when German chamomile is conventionally used.
authors.affiliation: Laboratory of Clinical Pharmaceutics, Faculty of Pharmaceutical Sciences, Sojo University, Kumamoto, 860-0082, Japan. iogata@ph.sojo-u.ac.jp
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ogata
authors.forename: Takuya
authors.initials: T
authors.lastname: Kawanai
authors.forename: Erika
authors.initials: E
authors.lastname: Hashimoto
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
authors.forename: Hakaru
authors.initials: H
authors.lastname: Seo
mesh_terms: D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D061945:Caspase Inhibitors; D002462:Cell Membrane / Q000378:metabolism; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004171:Diploidy; D004305:Dose-Response Relationship, Drug; D035264:Flowers / Q000737:chemistry*; D031168:Matricaria / Q000737:chemistry*; D010718:Phosphatidylserines / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D012717:Sesquiterpenes / Q000633:toxicity*; D013499:Surface Properties / Q000187:drug effects; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects*; D013997:Time Factors
chemical_list: D017304:Annexin A5; D061945:Caspase Inhibitors; D010718:Phosphatidylserines; D010936:Plant Extracts; D012717:Sesquiterpenes; C548414:bisabololoxide A