The immunosuppressive activities of two abortifacient proteins isolated from the seeds of bitter melon (Momordica charantia).

摘要: Two abortifacient proteins, alpha- and beta-momorcharin, have been purified from the seeds of bitter melon (Momordica charantia). It was found that non-cytotoxic concentrations these plant proteins can significantly inhibit mitogenic responses mouse splenocytes to concanavalin A, phytohaemagglutinin lipopolysaccharide in a dose-dependent manner. In addition, alloantigen-induced lymphoproliferation vitro generation primary cytotoxic lymphocyte response were severely suppressed presence proteins. contrast, cytolytic activity lymphocytes natural killer cells unimpaired by exposure momorcharin. On other hand, clear decrease functional capacity macrophages, such as cytostatic phagocytic activities, observed under similar conditions. vivo studies shown single injections nontoxic microgram amounts momorcharin into mice resulted significant depression delayed-type hypersensitivity well humoral antibody formation sheep red blood cells. Similarly, thioglycollate-induced migration macrophages also suppressed. Interestingly, activation not appreciably affected. Our data suggests potent immunosuppressive effect beta-momorcharin is unlikely be due direct lymphocytotoxicity or shift kinetic parameter immune response.