Cells belonging to the innate immune system, known as natural killer (NK) cells, act as the first line of defense against developing neoplasms. We have previously shown in a leukemia-induced tumor model (mouse) that a proprietary extract (CVT-E002), of North American ginseng, administered in the diet, significantly increased the absolute numbers of NK cells, significantly decreased leukemia cells and significantly increased the life span of CVT-E002-fed leukemic mice. In the present study, we assessed the efficacy of this extract to inhibit the spontaneous development of tumors in elderly mice of the cancer-prone C3H strain. Dietary CVT-E002 was fed for approximately a year beginning when mice were almost 2 years of age. Control mice, consuming the same chow without CVT-E002, all developed assorted, palpable tumors between 22 and 33 months, while all mice consuming CVT-E002 remained alive and tumor-free until they were purposely euthanized as healthy animals. The absolute numbers of NK cells at euthanasia, in CVT-E002-consuming mice, were significantly elevated in both the spleen and bone marrow. Given these profoundly positive results and the fact that CVT-E002 already exists in the marketplace under the label Cold-fX®, the potential for cancer prevention in humans becomes apparent.
Keywords: cancer; elderly; ginseng; immunity; mice.
Copyright © 2012 John Wiley & Sons, Ltd.