title: Possible use of quercetin, an antioxidant, for protection of cells suffering from overload of intracellular Ca2+: a model experiment.
abstract: Quercetin is known to protect the cells suffering from oxidative stress. The oxidative stress elevates intracellular Ca(2+) concentration, one of the phenomena responsible for cell death. Therefore, we hypothesized that quercetin would protect the cells suffering from overload of intracellular Ca(2+). To test the hypothesis, the effects of quercetin on the cells suffering from oxidative stress and intracellular Ca(2+) overload were examined by using a flow cytometer with appropriate fluorescence probes (propidium iodide, fluo-3-AM, and annexin V-FITC) and rat thymocytes. The concentrations (1-30 microM) of quercetin to protect the cells suffering from intracellular Ca(2+) overload by A23187, a calcium ionophore, were similar to those for the cells suffering from oxidative stress by H(2)O(2). The cell death respectively induced by H(2)O(2) and A23187 was significantly suppressed by removal of external Ca(2+). Furthermore, quercetin greatly delayed the process of Ca(2+)-dependent cell death although it did not significantly affect the elevation of intracellular Ca(2+) concentration by H(2)O(2) and A23187, respectively. It is concluded that quercetin can protect the cells from oxidative injury in spite of increased concentration of intracellular Ca(2+). Results suggest that quercetin is also used for protection of cells suffering from overload of intracellular Ca(2+).
authors.affiliation: Laboratory of Cellular Signaling, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Sakanashi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Oyama
authors.forename: Hiroko
authors.initials: H
authors.lastname: Matsui
authors.forename: Toshihisa B
authors.initials: TB
authors.lastname: Oyama
authors.forename: Tomohiro M
authors.initials: TM
authors.lastname: Oyama
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Hitomi
authors.initials: H
authors.lastname: Sakai
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D019610:Cytoprotection; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D000001:Calcimycin; D011794:Quercetin; D002118:Calcium