Chemopreventive effects of heat-processed Panax quinquefolius root on human breast cancer cells.
BACKGROUND
Former studies have shown that extract from American ginseng (Panax quinquefolius) may possess certain antiproliferative effects on cancer cells. In this study, the chemical constituents of both untreated and heat-processed American ginseng and their antiproliferative activities on human breast cancer cells were evaluated.


METHODS
American ginseng roots were steamed at 120 degrees C for 1 h or 2 h. The major ginsenosides in the two steamed and in the unsteamed extracts were quantitatively determined using high performance liquid chromatography (HPLC). The antiproliferative activities of these extracts and individual ginsenosides on MCF-7 and MDA-MB-231 breast cancer cells were assayed using the MTS method. The effects of the extracts and the ginsenosides on the induction of cell apoptosis, the expression of cyclins A and D1, and cell cycle arrest were evaluated.


RESULTS
Compared to the untreated extract, heat-processing reduced the content of ginsenosides Rb1, Re, Rc and Rd, and increased the content of Rg2 and Rg3. After 2 h steaming, the percent content of ginsenoside Rg3 was increased from 0.06% to 5.9%. Compared to the unsteamed extract, the 2 h steamed extract significantly increased the antiproliferative activity and significantly reduced the number of viable cells. The steamed extract also significantly reduced the expression of cyclin A and cyclin D1. The cell cycle assay showed that the steamed extract and ginsenoside Rg3 arrested cancer cells in G1-phase.


CONCLUSIONS
Heat-processing of American ginseng root significantly increases antiproliferative activity and influences the cell cycle profile.
Wang
Chong-Zhi
CZ
Tang Center for Herbal Medicine Research, The Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA.
Aung
Han H
HH
Zhang
Bin
B
Sun
Shi
S
Li
Xiao-Li
XL
He
Hui
H
Xie
Jing-Tian
JT
He
Tong-Chuan
TC
Du
Wei
W
Yuan
Chun-Su
CS
D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D002453:Cell Cycle / Q000187:drug effects; D016213:Cyclins / Q000096:biosynthesis; D036145:Ginsenosides / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology*; D006361:Heating; D006801:Humans; D005894:Panax / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry
D016213:Cyclins; D036145:Ginsenosides; D010936:Plant Extracts