CHARACTERISTIC IMMUNOSTIMULATION BY ANGELAN ISOLATED FROM ANGELICA-GIGAS NAKAI

The immunopharmacological characteristics of angelan, a polysaccharide purified from Angelica gigas Nakai, were investigated in relation to the specificity to immune cells. The treatment of angelan increased th e expression of IL-2, IL-4, IL-6, and IFN-gamma. The expression of IL- 6 and IFN-gamma was rapidly augmented but that of IL-2 responded later . In the case of IL-4, angelan stimulated at early time after exposure but down-regulated thereafter. These results suggested that macrophag es and natural killer cells involved in nonspecific immunity were prim arily activated and helper T cells were secondarily affected by angela n. Angelan also had lympho-proliferative potential to B cells, specifi cally. The specificity of angelan was also elucidated in a cell fracti onation experiment. The activated B cells by angelan also increased an tibody production. The direct activation of B cells, macrophages, and accessory cells and the indirect activation of helper T cells coordina tely increased immune functions such as in vitro and in vivo T-depende nt immunization and antibody production. The experiment of host resist ance to syngeneic tumors also showed that angelan potentiated the immu ne functions. In conclusion, angelan, a purified polysaccharide from a n oriental herbal drug, showed characteristic immunostimulation, which was different from clinically used polysaccharides such as lentinan a nd PSK. (C) 1998 Elsevier Science B.V. All rights reserved.