B-CELL STIMULATING ACTIVITY OF SEAWEED EXTRACTS

The activity of seaweed extracts on murine and human lymphocytes was s tudied in vitro. The extracts of some kinds of seaweed, such as Hiziki a fusiformis and Meristotheca papulosa, stimulated normal mouse spleen cells to proliferate. The responder cells are B cells, because the re sponse was depleted by the treatment of spleen cells with anti-immunog lobulin (Ig) antibody and complement and being passed through a nylon wool column. This response is not due to lipopolysaccharide (LPS) cont amination, because seaweed extracts can stimulate spleen cells of C3H/ HeJ mice which are LPS low responders. Seaweed extracts also enhanced Ig production by B cells and tumor necrosis factor (TNF) production by macrophages. Furthermore, seaweed extracts stimulated human lymphocyt es to proliferate. All these B cell stimulating activities of seaweed extracts associated with glycoproteins whose molecular weights resided in 100 kD. These results suggest that seaweed extracts have stimulati ng activity on B cells and macrophages and this ability could be used clinically for the modulation of immune responses. (C) 1997 Internatio nal Society for Immunopharmacology.