5,6-Dihydroxy-3,7,4'-trimethoxyflavonol induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma cells.
5,6-Dihydroxy-3,7,4'-trimethoxyflavonol (AH5), 5,6,3'-trihydroxy-3,7,4'-trimethoxyflavonol (AH22), artemetin, and oroxylin A are four flavonoids with the same 2-phenyl-chromone skeleton isolated from the Chinese herb Aster himalaicus. The aim of this study was to evaluate the structure-activity relationship of these four analogs and the mediation of AH5 cytotoxicity via G2/M arrest and apoptosis in human hepatocellular carcinoma (HCC) cells. 3-(4,5-Dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated AH5 showed the better potency to inhibit proliferation in human HCC cells, which suggested hydroxyl binding to C6 is necessary to anticancer properties, whereas binding to C3' attenuated the activities and increased toxicity in tested cells. Flow cytometry analysis revealed that AH5-induced G2/M arrest and significantly apoptosis in these cell lines. HepG-2 cells were used to further evaluate the antitumor effects and mechanisms of AH5. AH5-induced apoptosis was further confirmed by 4',6-diamidino-2-phenylindole (DAPI) staining and the increased ratio of Bax/Bcl-2. Moreover, AH5 induced the release of cytochrome C and the activation of caspase-9 and caspase-3, thus suggesting mitochondria activation might be involved. Western blot showed that AH5 induced the phosphorylation of Cdc2 and decreased the level of Cyclin B1. These results demonstrated that AH5 could be a proapoptotic leading compound for developing novel anticancer drugs.
a School of Ocean , Shandong University , Weihai 264209 , China.
Xin-Xin
XX
Zhao
a School of Ocean , Shandong University , Weihai 264209 , China.
Juan-Juan
JJ
Chang
a School of Ocean , Shandong University , Weihai 264209 , China.
Qi-Lin
QL
Wang
a School of Ocean , Shandong University , Weihai 264209 , China.
Rong
R
Lu
a School of Ocean , Shandong University , Weihai 264209 , China.
Ling-Jun
LJ
Li
a School of Ocean , Shandong University , Weihai 264209 , China.
Xiao
X
Sun
a School of Ocean , Shandong University , Weihai 264209 , China.
Wei-Dong
WD
Xie
a School of Ocean , Shandong University , Weihai 264209 , China.|b School of Pharmaceutical Sciences , Shandong University , Jinan 250012 , China.
Xia
X
Li
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy*; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D056744:Cyclin B1 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D015195:Drug Design; D005419:Flavonoids / Q000737:chemistry; D044948:Flavonols / Q000737:chemistry / Q000494:pharmacology*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D056945:Hep G2 Cells / Q000187:drug effects; D006801:Humans; D007211:Indoles / Q000737:chemistry; D008113:Liver Neoplasms / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects; D015394:Molecular Structure; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013329:Structure-Activity Relationship
C000613446:5,6,3'-trihydroxy-3,7,4'-trimethoxyflavonol; C000613445:5,6-dihydroxy-3,7,4'-trimethoxyflavonol; D000970:Antineoplastic Agents; D056744:Cyclin B1; D005419:Flavonoids; D044948:Flavonols; D007211:Indoles; D019253:Proto-Oncogene Proteins c-bcl-2; C007293:DAPI; C054132:artemetin; D045304:Cytochromes c; D053148:Caspase 3; D053453:Caspase 9
5,6-dihydroxy-3,7,4′-trimethoxyflavonol; G2/M arrest; Keywords; apoptosis; hepatocellular carcinoma