| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2004: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Research Abstract |
Lentinan has been known as an antitumor polysaccharide contained in Lentinula edodes, and its molecular weight was estimated to be more than 400,000. Lentinan shows the antitumor activity through host-mediated, because it does not kill cancer cells. However, it has not been ascertained whether or not lentinan was absorbed in intestine. In this study, co-culture system using intestinal epithelial cell line, caco2 cells (apical side), and macrophage cell lines, RAW 264.7 cells (basolateral side), was applied to clarify how lentinan stimulated macrophage. Caco2 cells (2.5×10^5 cells/well) were treated with 50 μg/ml lentinan, and then were co-cultured with RAW 264.7 cells (5×10^5 cells/well). TNF-α production was detected just in basolateral side (150 pg), not in apical side. When catalase was added in basolateral side in the same condition, TNF-α production was inhibited to 50%, but superoxide dismutase did not. RAW 264.7 cells stimulated directly with lentinan did not produce TNF-α. Furthermore, when caco2 cells were cultured with lentinan at the same concentration without RAW 264.7 cells, they did not produce TNF-α in both sides. Neither lentinan was detected in basolateral side. These findings suggested that intestinal epithelial cells stimulated with lentinan produced H_2O_2 and newly produced H_2O_2 played an important role in cell to cell cross talking to enhance TNF-α production from macrophages.
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