Adjuvant action of Chenopodium quinoa saponins on the induction of antibody responses to intragastric and intranasal administered antigens in mice.

Saponins extracted from the seed of Chenopodium quinoa (quinoa) were studied for their ability to act as mucosal adjuvants upon their intragastric or intranasal administration together with model antigens in mice. Quinoa saponins, co-administered intragastrically or intranasally with cholera toxin or ovalbumin, potentiated specific IgG and IgA antibody responses to the antigens in serum, intestinal and lung secretions. The potentiating effect of the saponins appeared, to some extent, mediated by increased permeability of the mucosa, allowing increased uptake of the antigen. The intragastric administration of 99mTc-radio-labeled human serum albumin together with quinoa saponins revealed an increased presence of the radiolabeled protein in blood, liver, spleen and lungs of mice. This study indicates the potential of quinoa saponins as adjuvants for mucosally administered vaccines.