title: Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells.
abstract: Quercetin is one of the naturally occurring dietary flavonol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.
authors.affiliation: Department of Hematology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Guomin
authors.initials: G
authors.lastname: Niu
authors.forename: Songmei
authors.initials: S
authors.lastname: Yin
authors.forename: Shuangfeng
authors.initials: S
authors.lastname: Xie
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Li
authors.forename: Danian
authors.initials: D
authors.lastname: Nie
authors.forename: Liping
authors.initials: L
authors.lastname: Ma
authors.forename: Xiuju
authors.initials: X
authors.lastname: Wang
authors.forename: Yudan
authors.initials: Y
authors.lastname: Wu
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism*; D049109:Cell Proliferation / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004789:Enzyme Activation; D018922:HL-60 Cells; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011794:Quercetin / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D011794:Quercetin; D051546:Cyclooxygenase 2; D053148:Caspase 3