| Abstract: | In the course of screening for immunomodulators, we found a significant blastogenic activity specific for splenic B cells
in the extracts of safflower (Carthamus tinctorius L.). Active fractions termed SF1 and SF2 were purified from dried petals
of safflower by boiling water extraction, ethanol precipitation and Sepharose CL-2B column chromatography. The elution profiles
of the gel filtration indicated that the molecular weight of SF1 and SF2 was estimated to be more than 100 kD. Major components
of SF1 and SF2 seem to be polysaccharides, and structural analysis of alditol acetate derivatives by GC-MS revealed some differences
between SF1 and SF2 in the sugar component. Biological activities of SF1 and SF2 on B cells and macrophages were examined
in comparison with lipopolysaccharides (LPS). SF1 and SF2 induced both the proliferation and the IgM production of B cells
to the equivalent level as those induced by LPS. In macrophages, SF1 and SF2 effectively stimulated the production of NO.
However, SF1 stimulated the production of IL-1, IL-6, and TNF as much as LPS, while SF2 induced them only weakly or not at
all. Thus, these results suggest that SF1 and SF2 activate B cells and macrophages in different mechanisms.
This revised version was published online in June 2006 with corrections to the Cover Date. |
