Induction of apoptosis by esculetin in human leukemia cells.
Esculetin, a coumarin compound, has been shown to exhibit antioxidant and anti-inflammatory effects. In the present study, esculetin was found to inhibit the survival of human promyelocytic leukemia HL-60 cells in a concentration-dependent and time-dependent manner. HL-60 cells underwent internucleosomal DNA fragmentation and morphological changes characteristic of apoptosis after a 24-h treatment with esculetin (100 microM). Flow cytometric analysis showed that the hypodiploid nuclei of HL-60 cells were increased to 40.93% after a 36-h treatment with esculetin (100 microM). Further investigation showed that esculetin induced the release of cytochrome c from mitochondria into cytosol in a time-dependent and concentration-dependent manner. Moreover, esculetin application reduced Bcl-2 protein expression to 58% after 9 h as compared with that time at 0. Cysteine protease 32 kDa proenzyme (CPP32), a caspase 3, was activated and its substrate, poly (adenosine diphosphate-ribose) polymerase, was cleaved after a 24-h treatment of HL-60 cells with esculetin. These data suggest that esculetin induces apoptosis in human leukemia cells by increasing cytosolic translocation of cytochrome c and activation of CPP32.
Department and Institute of Biochemistry, Chung Shan Medical and Dental College, No. 110, Section 1, Chien Kuo N. Road, 402, Taichung, Taiwan.
C Y
CY
Chu
Y Y
YY
Tsai
C J
CJ
Wang
W L
WL
Lin
T H
TH
Tseng
D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003574:Cytochrome c Group / Q000187:drug effects / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D018922:HL-60 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D011065:Poly(ADP-ribose) Polymerases / Q000187:drug effects / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014468:Umbelliferones / Q000494:pharmacology*
D000975:Antioxidants; D003574:Cytochrome c Group; D019253:Proto-Oncogene Proteins c-bcl-2; D014468:Umbelliferones; D011065:Poly(ADP-ribose) Polymerases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; C007628:esculetin