Ling Zhi extract (LZE) is a herbal mushroom preparation which been used world wide for the prevention and treatment of various cancers. The current study was designed to evaluate these claims in human colon cancer cells in terms of cancer preventive mechanisms. Results have demonstrated induction of apoptosis, anti-inflammatory action and differential cytokine expression during induced inflammation in the human colonic carcinoma cell line, HT-29. LZE caused no cytotoxicity in HT-29 cells at doses less than 10,000 microg/ml. Increasing concentrations of LZE reduced prostaglandin E2 production, but increased nitric oxide production. LZE treatment induced apoptosis by increasing the activity of caspase-3. RT-PCR showed that LZE at a concentration of 5000 microg/ml decreased the expression of cyclooxygenase-2 mRNA. Among 42 cytokines tested by protein array in this study, supplementation of LZE at doses of 500 and 5000 microg/ml to HT-29 cells reduced the expression of interleukin-8, macrophage inflammatory protein 1-delta, vascular epithelial growth factor, and platelet-derived growth factor. These results suggest that LZE has pro-apoptotic and anti-inflammatory functions, as well as inhibitory effects on cytokine expression during early inflammation in colonic carcinoma cells, which may be of significance in the use of Chinese herbal alternative medicines for cancer prevention.
Copyright (c) 2004 John Wiley & Sons, Ltd.