ENHANCEMENT OF ANTIBODY-PRODUCTION IN MICE BY DIETARY SPIRULINA-PLATENSIS

Mice fed a Spirulina platensis diet showed increased numbers of spleni c antibody-producing cells in the primary immune response to sheep red blood cells (SRBC). However, immunoglobulin G (IgG)-antibody producti on in the secondary immune response was hardly affected. The percentag e of phagocytic cells in peritoneal macrophages from the mice fed S. p latensis diet, as well as the proliferation of spleen cells by either concanavalin A (Con A) or phytohemagglutinin (PHA) was significantly i ncreased. Addition of a hot-water extract of S. platensis (SHW) to an in vitro culture of spleen cells markedly increased proliferation of t hese cells, whereas culture of thymus cells was scarcely affected. The Spirulina extract also significantly enhanced interleukin-1 (IL-1) pr oduction from peritoneal macrophages. Addition to the in vitro spleen cell culture of SHW as well as the supernatant of macrophages stimulat ed with SHW resulted in enhancement of antibody production, that is, a n increase of the number of PFC. These results suggest that Spirulina enhances the immune response, particularly the primary response, by st imulating macrophage functions, phagocytosis, and IL-1 production.