American Ginseng inhibits induced COX-2 and NFKB activation in breast cancer cells.

Background: Epidemiologic evidence suggests reduced breast cancer mortality in users of American Ginseng (AG) (Panax quinquefolium). We hypothesized that AG extract decreases proliferation of human breast cancer cells via an anti-inflammatory effect applicable to the prevention of breast and other cancers.

Material And Methods: A defined lyophilized aqueous extract of AG (LEAG) was dissolved in DMSO 1mg/mL, and serially diluted in saline. The cell lines MDA MB 231 and MCF7 were stimulated with the phorbol ester PDBu and treated with 100-500 mcg/mL LEAG. Proliferation was measured by MDA assay. Induced COX-2 expression was assayed by ELISA. Activation of NFkappaB by phosphorylation of the p65 subunit was quantified by CASE (cellular activation of signaling ELISA).

Results: Both cell lines had reduced proliferation when treated with LEAG. PDBu stimulation of MDA MB 231 increased expression of the COX-2 protein 20-fold at 48 hours (P<0.005). COX-2 protein expression remained at baseline concentrations in PDBu- treated MDA MB 231 cells exposed to 100 mcg/mL LEAG. The CASE assay showed a 4-fold increase in p65 activation 24 hours after PDBu treatment in normal medium, while phosphorylated p65 dropped below baseline in the cells treated with PDBu plus LEAG.

Conclusion: In MDA MB 231, COX-2 was inducible with PDBu. This induced COX-2 expression was blocked by 100 microgram/mL LEAG in a time course consistent with the decline in the activated p65 subunit of NFkappaB. These results provide an anti-inflammatory mechanism for a possible anti-cancer effect of American Ginseng.