title: Bisabololoxide A, one of the constituents in German chamomile extract, attenuates cell death induced by calcium overload.
abstract: Bisabololoxide A (BSBO), main constituents in German chamomile extract, is responsible for antipruritic effect. In previous study, the incubation with 30-100 μM BSBO for 24 h exerted cytotoxic and proapoptotic effects on rat thymocytes. To further characterize BSBO cytotoxicity, the effect on the cells suffering from calcium overload by calcium ionophore A23187 was examined. A23187 induced Ca(2+) -dependent cell death. Contrary to our expectation, 1-10 μM BSBO inhibited A23187-induced increase in cell lethality of rat thymocytes. BSBO attenuated A23187-induced increases in populations of shrunken living cells, phosphatidylserine-exposed living cells, and dead cells, without affecting the increase in intracellular Ca(2+) concentration and the Ca(2+) -dependent hyperpolarization. The effect of BSBO on A23187-treated cells may be unique because the activation of Ca(2+) -dependent K(+) channels is required for cell shrinkage, externalization of phosphatidylserine, and cell death in some cells. The cell death induced by A23187 was not inhibited by Z-VAD-FMK, a pan-inhibitor of caspases. Thus, the cell death may be a necrosis with some features observed during an early stage of apoptosis. These results suggest that BSBO at low micromolar concentrations is cytoprotective against calcium overload.
authors.affiliation: Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima, 770-8502, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Fukunaga
authors.forename: Yumi
authors.initials: Y
authors.lastname: Hirao
authors.forename: Ikuko
authors.initials: I
authors.lastname: Ogata-Ikeda
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Hakaru
authors.initials: H
authors.lastname: Seo
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000590:Amino Acid Chloromethyl Ketones; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000009:adverse effects*; D002478:Cells, Cultured; D031168:Matricaria / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012717:Sesquiterpenes / Q000494:pharmacology*; D060168:Thymocytes / Q000187:drug effects*
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D010936:Plant Extracts; D012717:Sesquiterpenes; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; C548414:bisabololoxide A; D000001:Calcimycin; D002118:Calcium
keywords: bisabololoxide A; calcium overload; cell death; chamomile extract