Foamy Matters: an Update on Saponins and Their Use As Immunoadjuvants

Immunoadjuvant spp. tree saponins stimulate both cellular and humoral responses, significantly widening vaccine target pathogen spectra. Host toxicity of specific saponins, fractions and extracts may be rather low and further reduced using lipid-based delivery systems. Saponins contain a hydrophobic central aglycone decorated with several sugar residues, posing a challenge for viable chemical synthesis. These, however, may provide simpler analogs. Saponin chemistry affords characteristic interactions with cell membranes, which are essential for its mechanism of action. Natural sources include barks and, more recently, leaves. Sustainable large-scale supply can use young plants grown in clonal gardens and elicitation treatments. genomic studies will most likely buttress future synthetic biology-based saponin production efforts.