[Vitexicarpin, a flavonoid from Vitex trifolia L., induces apoptosis in K562 cells via mitochondria-controlled apoptotic pathway].
OBJECTIVE
To investigate the inhibitory effect of vitexicarpin on the proliferation of human cancer cells and its mechanism of action.


METHODS
The inhibitory effect of vitexicarpin on the proliferation of human cancer cells was evaluated by the SRB method and its apoptosis-inducing effect was demonstrated by morphological observation under light microscope, flow cytometric analysis and agarose gel electrophoresis. The proteins related to apoptosis were examined by Western blotting analysis.


RESULTS
Vitexicarpin significantly inhibited the proliferation of human cancer cells, A2780, HCT-15, HT-1080 and K562, with the IC50 values of (19.1 +/- 2.4) micromol x L(-1) for A2780(48 h), (0.66 +/- 0.10) micromol x L(-1) for HCT-15(48 h), (0.44 +/- 0.06) micromol x L(-1) for HT-1080 (48 h) and (0.28 +/- 0.14) micromol x L(-1) for K562 (24 h). The cells treated with vitexicarpin showed characteristic morphology typical for apoptosis and gave dose-dependent sub-G0/G1 peak in the flow cytometric analysis and DNA ladder on agarose gel electrophoresis. In Western blotting analysis, the cleavage of PARP and caspase-3, the release of cytochrome c from mitochondria into the cytosol, the decrease of Bcl-2 expression level, and the down-regulation of the ratio of Bcl-2/Bax expression level were examined in the K562 cells treated with vitexicarpin.


CONCLUSIONS
Vitexicarpin induces apoptosis in K562 cells via mitochondria-controlled apoptotic pathway.
Wang
Hai-yan
HY
Tianjin Institute for Biomedicinal Research, Tianjin 300384, China.
Cai
Bing
B
Cui
Cheng-bin
CB
Zhang
Dong-yun
DY
Yang
Bao-feng
BF
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D020014:K562 Cells; D008928:Mitochondria / Q000201:enzymology / Q000502:physiology*; D010946:Plants, Medicinal / Q000737:chemistry; D020950:Vitex / Q000737:chemistry
D000972:Antineoplastic Agents, Phytogenic; D005419:Flavonoids; C054133:casticin