Class specific influence of dietary Spirulina platensis on antibody production in mice

In the present study, we investigated antibody productions of IgA and other classes, such as IgE and IgG1, in mice as possible evidence of the protect ive effects of Spirulina toward food allergy and microbial infection. An in crease of IgE antibody level in the serum was observed in the mice that wer e orally immunized with crude shrimp extract as an antigen (Ag group). The antibody level, however, was not further enhanced by treatment with Spiruli na extract (SpHW). IgG1 antibody, on the other hand, which was increased by antigen administration, was further enhanced by Spirulina extract. It was noted that the ISA antibody level in the intestinal contents was significan tly enhanced by treatment with Spirulina extract concurrently ingested with shrimp antigen, in comparison with that of the Ag group treated with shrim p antigen alone. An enhancement of IgA antibody production by Spirulina ext ract was also observed in culture supernatant of lymphoid cells, especially in the spleen and mesenteric lymph node from mice treated with Spirulina e xtract for 4 weeks before antigen stimulation. These results suggest that S pirulina may at least neither induce nor enhance allergic reaction such as food allergy dependent on an IgE antibody, and that when ingested both conc urrently with antigen and before antigen stimulation, it may significantly enhance the IgA antibody level to protect against allergic reaction.