The ethanol extract isolated from Weiqi Decoction induces G₂/M arrest and apoptosis in AGS cells.
OBJECTIVE
To evaluate the effects of the ethanol extract isolated from Weiqi Decoction (WQD-EE) on AGS cell proliferation and apoptosis.


METHODS
By using high-performance liquid chromatography with ultraviolet detectors (HPLC-UV) assay and MTT method, the main compounds in WQD-EE and cell viability were detected. And cell cycle distributions were determined by flow cytometry with propidium iodine (PI) staining while apoptosis was detected by flow cytometry with annexin V/PI double staining. Finally, caspase-3 activities were measured by colorimetric method and protein expression was determined by Western blotting.


RESULTS
HPLC analysis showed that naringin (35.92 μg/mg), nobiletin (21.98 μg/mg), neohesperidin (17.98 μg/mg) and tangeretin (0.756 μg/mg) may be the main compounds in WQD-EE. WQD-EE not only inhibited AGS and MCF 7 cell proliferation in a dose-dependent manner, but also blocked cell cycle progression at G2/M stage as well as inducing cell apoptosis at concentrations triggering significant inhibition of proliferation and cell cycle arrest in AGS cells. While at 0.5 mg/mL, WQD-EE significantly increased caspase-3 activity by 2.75 and 7.47 times at 24 h and 48 h, respectively. Moreover, WQD-EE in one hand reduced protein expressions of p53 and cyclin B1, and in other hand enhanced protein expressions of cytochrome c and Bax. Protein levels of Bcl-2, Fas L and Fas were not significantly affected by WQD-EE.


CONCLUSIONS
WQD-EE inhibits AGS cell proliferation through G2/M arrest due to down-regulation of cyclin B1 protein expression, and promotes apoptosis by caspase-3 and mitochondria-dependent pathways, but not by p53-dependent pathway.
Institute of Digestive Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China.
Hai-lian
HL
Shi
Bao
B
Tan
Guang
G
Ji
Lan
L
Lu
Jian-qun
JQ
Xie
D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D000431:Ethanol / Q000737:chemistry*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D006801:Humans; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects*; D009363:Neoplasm Proteins / Q000378:metabolism; D010936:Plant Extracts / Q000302:isolation & purification*
D004365:Drugs, Chinese Herbal; D009363:Neoplasm Proteins; D010936:Plant Extracts; C000595070:weiqi; D000431:Ethanol; D053148:Caspase 3