Chaga mushroom (Inonotus obliquus) induces G0/G1 arrest and apoptosis in human hepatoma HepG2 cells.
OBJECTIVE
To investigate the anti-proliferative and apoptotic effects of Chaga mushroom (Inonotus obliquus) water extract on human hepatoma cell lines, HepG2 and Hep3B cells.


METHODS
The cytotoxicity of Chaga extract was screened by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. Morphological observation, flow cytometry analysis, Western blot were employed to elucidate the cytotoxic mechanism of Chaga extract.


RESULTS
HepG2 cells were more sensitive to Chaga extract than Hep3B cells, as demonstrated by markedly reduced cell viability. Chaga extract inhibited the cell growth in a dose-dependent manner, which was accompanied with G0/G1-phase arrest and apoptotic cell death. In addition, G0/G1 arrest in the cell cycle was closely associated with down-regulation of p53, pRb, p27, cyclins D1, D2, E, cyclin-dependent kinase (Cdk) 2, Cdk4, and Cdk6 expression.


CONCLUSIONS
Chaga mushroom may provide a new therapeutic option, as a potential anticancer agent, in the treatment of hepatoma.
Youn
Myung-Ja
MJ
Vestibulocochlear Research Center, Wonkwang University School of Medicine, #344-2, Shinyoung-dong, Iksan, Jeonbuk 570-749, Korea.
Kim
Jin-Kyung
JK
Park
Seong-Yeol
SY
Kim
Yunha
Y
Kim
Se-Jin
SJ
Lee
Jin-Seok
JS
Chai
Kyu-Yun
KY
Kim
Hye-Jung
HJ
Cui
Ming-Xun
MX
So
Hong-Seob
HS
Kim
Ki-Young
KY
Park
Raekil
R
D000363:Agaricales / Q000737:chemistry*; D017209:Apoptosis / Q000187:drug effects*; D001688:Biological Products / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D045744:Cell Line, Tumor; D003603:Cytotoxins / Q000494:pharmacology*; D016193:G1 Phase / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D008519:Medicine, Traditional; D016192:Resting Phase, Cell Cycle / Q000187:drug effects
D001688:Biological Products; D003603:Cytotoxins