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The anti-inflammatory activities of six benzoxazinoids isolated from roots of Coix lachryma-jobi var. ma-yuen and structurally related synthetic materials were investigated by measurement of their inhibition of histamine release from rat mast cells stimulated with concanavalin A (Con A) and sensitized with immunoglobulin E (reagin). Because the inhibition data for either Con A or IgE with these compounds were comparable, Con A can be used for rapid first-stage screening of active compounds. Four glycosides out of the eleven compounds investigated were not active. Other results showed that the free hydroxyl group at the 2-position in the benzoxazinone skeleton is important for the expression of inhibitory activity.

SummaryAfter an exposure to ionising radiation, cells can quickly repair damage to their genomes; however, a few unrepairable DNA doublestrand breaks (DSBs) emerge in the nucleus in a prolonged culture and perpetuate as long as the culture continues. These DSBs may be retained forever in cells such as non-dividing ageing tissues, which are resistant to apoptosis. We show that such unrepairable DSBs, which had been advocated by the classical target theory as the 'radiation hit', could account for permanent growth arrest and premature senescence. The unrepairable DSBs build up with repeated irradiation, which accounts for an accumulated dose. Because these DSBs tend to be paired, we propose that the untethered and 'torn-off' molecular structures at the broken ends of the DNA result in an alteration of chromatin structure, which protects the ends of the DNA from genomic catastrophe. Such biochemical responses are important for cell survival but may cause gradual tissue malfunction, which could lead to the late effects of radiation exposure. Thus, understanding the biology of unrepairable damage will provide new insights into the long-term effects of radiation.

Previous studies of blood cells from atomic bomb survivors have shown that frequencies of chromosome aberrations and somatic mutations are elevated in heavily exposed survivors and that T-cell functions and the number of mature T cells are decreased in the survivors who were exposed to radiation as adults. Current progress in flow cytometry allows a sophisticated analysis of various subsets of T, B and NK cells. In the present study, proportions of such subsets in peripheral blood lymphocytes from atomic bomb survivors (159 survivors estimated to be exposed to > or =1.5 Gy) and 252 controls were measured using multiple combinations of monoclonal antibodies to lymphocyte differentiation antigens to investigate whether the previous radiation exposure had altered the composition of the subsets. Among T-cell subsets, the proportion of CD4+ T-cell subsets was decreased significantly in the heavily exposed survivors; this tendency was apparent for the CD4+CD45RA+ naive T-cell subset. However, there were no significant differences in the proportions of CD8+ T-cell subsets between the exposed survivors and controls. As for the B-cell subsets, the proportion of both CD5+ and CD5 B cells as well as CD23+ and CD23- B cells increased in the heavily exposed survivors. Further, no effect of radiation was found in the proportion of NK-cell subsets. These results strongly suggest that previous radiation exposure altered the composition of T and B cells in the peripheral blood of atomic bomb survivors, and they raise the possibility that atomic bomb radiation may have affected the developmental processes of T and B cells.

Ganoderma lucidum (G. lucidum Reishi), a traditional Chinese medical fungus, has been used as a health-promoting supplement due to its anti-tumor and immuno-modulating effects. The major bioactive components in G. lucidum are reported to be polysaccharide [1][2][3] and gonoderic acid. 4)Traditionally, the fruiting body has been the only part of G. lucidum that is used for medical purposes. Recently, Sliva et al. have reported the extract of G. lucidum using boiling water suppresses the mobility of breast and prostate cancers by inhibiting nuclear factor (NF)-kB. 5,6) As G. lucidum is available as a dietary supplement in various forms (mushroom powder, purified whole spores, broken spores, or mixtures), they compared their biological activity on cell migration and inhibition of NF-kB in human cancer cells and concluded the spores also show strong activity against human cancer cell.6) The possible role of mushrooms to prevent cancer has been summarized in several reviews. 7,8) Cancer inhibition by mushrooms or mushrooms polysaccharides was generally achieved through activating the immune response of the host rather than by directly inhibiting tumor cell growth. However, in medical mushroom research, polysaccharide and polysaccharide-peptides are known active anticancer compounds isolated from medicinal mushrooms such as maitake (Grifola frondosa), shiitake (Lentinula edodes), turkey tail (Coriolus versicolor) and reishi (G. lucidum). 9,10)The polysaccharides and polysaccharide-peptides are generally thought to exert their anti-tumor effects via a systemic effect on immunity. There is an evidence that the glucanprotein complex induces biological responses by binding to membrane compartment receptor three (CR3, or CD11b/CD18) on immune effectors cells such as macrophages.11) Furthermore, recent research has demonstrated that some of these mushroom-derived materials can produce direct cytotoxic effects on cancer cells. 12,13) A purified fraction by HPLC from the spores of G. lucidum guided by the inhibitory activity on HL-60 cell proliferation showed biological activity contains a mixture of long chain fatty acids with molecular weights in the range of m/z 250.0 to m/z 296.4, although as yet these could not be unambiguously authenticated. Therefore, in this study, using several authentic fatty acids predicted from our analytical data, we have compared the effect of the spore extract of G. lucidum with those of several authentic fatty acids on the inhibitory activity of HL-60 cell proliferation and the production of tumor necrosis factor (TNF) production induced by lipopolysaccharide (LPS) in a mouse macrophage preparation. MATERIALS AND METHODSThe spores (100 g) of G. lucidum, cultured at the area of Dabieshan, Anhui, China from October 2003 to July 2004 (Lot AFA), kindly supplied from Isukura Co., Ltd. (Tokyo) were dissolved in five volumes of 95% ethanol in a sealed bag, shaken gently at room temperature for 24 h and centrifuged at 10000ϫg for 20 min. The solution was evaporated to dryness on a rotary evaporator. T...

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