PDF file - 2.6MB, Effect of whole AG extract and different fractions of AG on IFN-γ-induced iNOS expression. The murine macrophage cell line (ANA-1 cells) was incubated for 12 hr with No AG (media only), the whole AG extract (260 �g/ml), or the indicated AG Fraction (260 �g/ml), washed, then exposed to IFN-γ (100 U/ml) for 0, 2, 4 and 8 hrs. Cell lysates were analyzed by Western blot analysis. C+, indicates the positive control, which was an archived ANA-1 cell lysate previously induced by IFN-γ, and known to have iNOS induction. The treatment was repeated 3 times to ensure consistency.
ARTICLE ABSTRACT
Ulcerative colitis is a chronic inflammatory condition associated with a high colon cancer risk. We have previously reported that American ginseng extract significantly reduced the inflammatory parameters of chemically induced colitis. The aim of this study was to further delineate the components of American ginseng that suppress colitis and prevent colon cancer. Among five different fractions of American ginseng (butanol, hexane, ethylacetate, dichloromethane, and water), a hexane fraction has particularly potent antioxidant and proapoptotic properties. The effects of this fraction were shown in a mouse macrophage cell line (ANA-1 cells), in a human lymphoblastoid cell line (TK6), and in an ex vivo model (CD4+/CD25− primary effector T cells). A key in vivo finding was that compared with the whole American ginseng extract, the hexane fraction of American ginseng was more potent in treating colitis in a dextran sodium sulfate (DSS) mouse model, as well as suppressing azoxymethane/DSS-induced colon cancer. Furthermore, terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL) labeling of inflammatory cells within the colonic mesenteric lymph nodes was elevated in mice consuming DSS + the hexane fraction of American ginseng. Results are consistent with our in vitro data and with the hypothesis that the hexane fraction of American ginseng has anti-inflammatory properties and drives inflammatory cell apoptosis in vivo, providing a mechanism by which this fraction protects from colitis in this DSS mouse model. This study moves us closer to understanding the molecular components of American ginseng that suppress colitis and prevent colon cancer associated with colitis. Cancer Prev Res; 5(4); 685–96. ©2012 AACR.
