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Hydroxylation at C4' or C6 is essential for apoptosis-inducing activity of flavanone through activation of the caspase-3 cascade and production of reactive oxygen species.
Free Radic Biol Med. 2004 Apr 01; 36(7):897-910.FR

Abstract

Previous studies demonstrated that hydroxyl groups play important roles in the antioxidative activities of flavonoids; however, the importance of structurally related hydroxylation in their apoptosis-inducing activities is still undefined. In the present study, flavanone with hydroxylation at C4' and C6 had a significant cytotoxic effect in human leukemia HL-60 cells accompanied by the occurrence of DNA ladders, apoptotic bodies, and hypodiploid cells, characteristics of apoptosis. The replacement of a hydroxyl group (OH) by a methoxyl (OCH3) group at C4' or C6 attenuated the apoptotic effect in cells, and there was no significant cytotocity of flavanone or flavanone with OH or OCH3 in C7-treated HL-60 cells. Induction of enzyme activity of caspase-3 and -9, but not caspase-1 and -8, accompanied by release of cytocrome C from mitochondria to cytosol and the appearance of cleaved of PARP (85 kDa), D4-GDI (23 kDa), and caspase-3 (p17/p15) fragments, was identified in 4'-OH- or 6-OH- flavanone-treated HL-60 cells. Caspase-3 and -9 inhibitors Ac-DEVD-FMK and Ac-LEHD-FMK, but not caspase-1 and -8 inhibitors Ac-YVAD-FMK and Ac-LETD-FMK, attenuated 4'-OH- or 6-OH-flavanone-induced cell death. And, inhibition of capsase-9 activity by Ac-LEHD-FMK suppresses caspase-3 protein procession induced by 4'-OH- and 6-OH-flavanone, indicative of caspase-9 activation locating upstream of caspase-3. A decrease in the antiapoptotic protein Mcl-1 and increases in the pro-apoptotic proteins Bax and Bad were found in 4'-OH- or 6-OH-flavanone-treated HL-60 cells. Induction of endogenous ROS production was detected in 4'-OH- or 6-OH-flavanone-treated HL-60 cells by the DCHF-DA assay. Antioxidants such as N-acetylcysteine (NAC), catalase (CAT), superoxide dismutase (SOD), and allopurinol (ALL), but not pyrrolidine dithiocarbamate (PDTC) or diphenylene iodonium (DPI), significantly inhibited 4'-OH- or 6-OH-flavanone-induced ROS production, with blocking of the apoptosis induced by 4'-OH- or 6-OH-flavanone. The apoptosis-inducing activity of 4'-OH- or 6-OH-flavanone was also observed in another leukemia cell line (Jurkat), but was not found in mature monocytic cells (THP-1) and normal human polymorphonuclear neutrophils (PMNs). This suggests that hydroxylation at C4' or C6 is important to the apoptosis-inducing activities of flavanone through ROS production, and that activation of the caspase-3 cascade, downstream of caspase-9 activation, is involved.

Authors+Show Affiliations

Ko CH
Graduate Institute of Pharmaceutical Sciences, School of Pharmacy, Taipei Medical University, Taipei, Taiwan.
Shen SC
No affiliation info available
Chen YC
No affiliation info available

MeSH

AcetylcysteineAllopurinolAntioxidantsApoptosisCarrier ProteinsCaspase 3CaspasesCatalaseCytochromes cDNA FragmentationFlavanonesFlow CytometryGenes, bcl-2Guanine Nucleotide Dissociation InhibitorsHL-60 CellsHumansHydroxylationMaleMyeloid Cell Leukemia Sequence 1 ProteinNeoplasm ProteinsPoly(ADP-ribose) PolymerasesProto-Oncogene Proteins c-bcl-2Reactive Oxygen SpeciesSuperoxide Dismutasebcl-2-Associated X Proteinbcl-Associated Death Proteinbcl-X Proteinrho Guanine Nucleotide Dissociation Inhibitor betarho-Specific Guanine Nucleotide Dissociation Inhibitors

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15019974

Citation

Ko, Ching Huai, et al. "Hydroxylation at C4' or C6 Is Essential for Apoptosis-inducing Activity of Flavanone Through Activation of the Caspase-3 Cascade and Production of Reactive Oxygen Species." Free Radical Biology & Medicine, vol. 36, no. 7, 2004, pp. 897-910.
Ko CH, Shen SC, Chen YC. Hydroxylation at C4' or C6 is essential for apoptosis-inducing activity of flavanone through activation of the caspase-3 cascade and production of reactive oxygen species. Free Radic Biol Med. 2004;36(7):897-910.
Ko, C. H., Shen, S. C., & Chen, Y. C. (2004). Hydroxylation at C4' or C6 is essential for apoptosis-inducing activity of flavanone through activation of the caspase-3 cascade and production of reactive oxygen species. Free Radical Biology & Medicine, 36(7), 897-910.
Ko CH, Shen SC, Chen YC. Hydroxylation at C4' or C6 Is Essential for Apoptosis-inducing Activity of Flavanone Through Activation of the Caspase-3 Cascade and Production of Reactive Oxygen Species. Free Radic Biol Med. 2004 Apr 1;36(7):897-910. PubMed PMID: 15019974.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Hydroxylation at C4' or C6 is essential for apoptosis-inducing activity of flavanone through activation of the caspase-3 cascade and production of reactive oxygen species. AU - Ko,Ching Huai, AU - Shen,Shing-Chuan, AU - Chen,Yen Chou, PY - 2003/07/29/received PY - 2003/12/17/revised PY - 2003/12/22/accepted PY - 2004/3/17/pubmed PY - 2004/12/22/medline PY - 2004/3/17/entrez SP - 897 EP - 910 JF - Free radical biology & medicine JO - Free Radic Biol Med VL - 36 IS - 7 N2 - Previous studies demonstrated that hydroxyl groups play important roles in the antioxidative activities of flavonoids; however, the importance of structurally related hydroxylation in their apoptosis-inducing activities is still undefined. In the present study, flavanone with hydroxylation at C4' and C6 had a significant cytotoxic effect in human leukemia HL-60 cells accompanied by the occurrence of DNA ladders, apoptotic bodies, and hypodiploid cells, characteristics of apoptosis. The replacement of a hydroxyl group (OH) by a methoxyl (OCH3) group at C4' or C6 attenuated the apoptotic effect in cells, and there was no significant cytotocity of flavanone or flavanone with OH or OCH3 in C7-treated HL-60 cells. Induction of enzyme activity of caspase-3 and -9, but not caspase-1 and -8, accompanied by release of cytocrome C from mitochondria to cytosol and the appearance of cleaved of PARP (85 kDa), D4-GDI (23 kDa), and caspase-3 (p17/p15) fragments, was identified in 4'-OH- or 6-OH- flavanone-treated HL-60 cells. Caspase-3 and -9 inhibitors Ac-DEVD-FMK and Ac-LEHD-FMK, but not caspase-1 and -8 inhibitors Ac-YVAD-FMK and Ac-LETD-FMK, attenuated 4'-OH- or 6-OH-flavanone-induced cell death. And, inhibition of capsase-9 activity by Ac-LEHD-FMK suppresses caspase-3 protein procession induced by 4'-OH- and 6-OH-flavanone, indicative of caspase-9 activation locating upstream of caspase-3. A decrease in the antiapoptotic protein Mcl-1 and increases in the pro-apoptotic proteins Bax and Bad were found in 4'-OH- or 6-OH-flavanone-treated HL-60 cells. Induction of endogenous ROS production was detected in 4'-OH- or 6-OH-flavanone-treated HL-60 cells by the DCHF-DA assay. Antioxidants such as N-acetylcysteine (NAC), catalase (CAT), superoxide dismutase (SOD), and allopurinol (ALL), but not pyrrolidine dithiocarbamate (PDTC) or diphenylene iodonium (DPI), significantly inhibited 4'-OH- or 6-OH-flavanone-induced ROS production, with blocking of the apoptosis induced by 4'-OH- or 6-OH-flavanone. The apoptosis-inducing activity of 4'-OH- or 6-OH-flavanone was also observed in another leukemia cell line (Jurkat), but was not found in mature monocytic cells (THP-1) and normal human polymorphonuclear neutrophils (PMNs). This suggests that hydroxylation at C4' or C6 is important to the apoptosis-inducing activities of flavanone through ROS production, and that activation of the caspase-3 cascade, downstream of caspase-9 activation, is involved. SN - 0891-5849 UR - https://www.unboundmedicine.com/medline/citation/15019974/Hydroxylation_at_C4'_or_C6_is_essential_for_apoptosis_inducing_activity_of_flavanone_through_activation_of_the_caspase_3_cascade_and_production_of_reactive_oxygen_species_ DB - PRIME DP - Unbound Medicine ER -
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