Strain dependent & selective modulation of murine humoral immune response by carrageenan.

Carrageenan (CGN), a polygalactan extracted from red algae, induced 90 per cent suppression of antibody response to sheep red blood cells in Balb/C strain as compared to the untreated controls. Whereas the treatment failed to induce suppression in C57BL/6 strain. The observed suppression of antibody response was significant on all days tested (up to 40 days) and the suppression induced by CGN was real and not due to any direct effect on antigen or on the assay system followed. On the other hand, as evident from foot-pad thickness, the delayed type hypersensitivity (DTH) was unaltered in Balb/C strain after CGN treatment.