Induction of apoptosis and inhibition of telomerase activity by aqueous extract from Platycodon grandiflorum in human lung carcinoma cells.
The objective of the present study was to investigate the effect of aqueous extract from the root of Platycodon grandiflorum (AEPG) on the cell growth and apoptosis in human lung carcinoma cell line A549. Exposure of A549 cells to AEPG resulted in growth inhibition and induction of apoptosis in a dose-dependent manner as measured by hemocytometer counts, fluorescence microscopy and flow cytometry analysis. This increase in apoptosis was associated with a decrease in Bcl-2 expression, an increase of Bax and an activation of caspase-3. AEPG treatment markedly inhibited the activity of telomerase in a dose-dependent fashion. Additionally, the expression of human telomerase reverse transcriptase (hTERT), a main determinant of the telomerase enzymatic activity, was progressively down-regulated by AEPG treatment. These findings suggest that the apoptotic events by AEPG were associated with the diminished telomerase activity and down-regulation of Bcl-2 expression.
Park
Dong Il
DI
Department of Oriental Medicine, Dongeui University College of Oriental Medicine and Research Institute of Oriental Medicine, Busan 614-052, Republic of Korea.
Lee
Jae Hun
JH
Moon
Sung-Kwon
SK
Kim
Cheorl-Ho
CH
Lee
Yong Tae
YT
Cheong
JaeHun
J
Choi
Byung Tae
BT
Choi
Yung Hyun
YH
D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D004789:Enzyme Activation; D006801:Humans; D008175:Lung Neoplasms; D010936:Plant Extracts / Q000494:pharmacology; D031238:Platycodon; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D014867:Water
D004268:DNA-Binding Proteins; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D014867:Water; D019098:Telomerase; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases