Proc Am Soc Clin Oncol 22: page 888, 2003 (abstr 3571)
AntiCancer pharmacology of careseng, a natural product of ginseng
W. Jia, H. Yan, X. Bu, G. Liu;
University of British Columbia, Vancouver, BC, Canada
Background: For thousands of years ginseng (Panax Quinquefolium L.) preparations have been used for health remedies. The main ingredients in ginseng with therapeutic activity are Ginseng saponins (ginsenosides) but only few of these ginsenosides, notably Rh1/2 and Rg3, demonstrate cytotoxicity on cancer cells. Since most ginseng preparations contain only trace amounts of these anticancer compounds, effects of direct inhibition on cancer cell growth are limited with regular ginseng extracts.
Method: In the present study, a specially formulated ginseng product, Careseng containing over 80% of Rh2 and Rh2-like ginsenosides, was tested on cultured breast, prostate, lung, pancreatic and brain cancer cell lines and in an intracranial glioma rat model to study anticancer properties.
Results: Our results showed that in vitro, Careseng induced G1 arrest and differentiation at low concentrations (<20ig/ml) and caused apoptosis at higher concentrations (>40ig/ml) in all cancer cell lines tested. Careseng induced apoptosis was independent of P53, but requisite of caspase activation, as DEVD, a caspase blocker completely abolished this activity. In all cancer cell lines, Careseng?apoptotic index was dose dependent. Furthermore, when Careseng was combined with Taxol, Mitoxantrone and Cisplatin in vitro, a synergistic effect on cytotoxicity was demonstrated. In a 9L glioma rat model, oral administration of Careseng?(25-50mg/kg) reduced mortality by 60%, and elongated the average life span of tumor bearing animals compared to controls (32+3 days versus 18+1 days; p<0.001). Acute (4000mg/kg) and chronic (300mg/kg/day for 8 weeks) toxicity tests in mice showed no significant adverse effects.
Conclusion: The above results demonstrate that Careseng has provocative and novel anticancer properties that render it an important new anticancer drug candidate which should be tested further in clinical studies.