Immunomodulatory Properties of Frondoside A, a Major Triterpene Glycoside from the North Atlantic Commercially Harvested Sea Cucumber Cucumaria frondosa

ABSTRACT Frondoside A, a major triterpene glycoside from North Atlantic commercially harvested sea cucumber Cucumaria frondosa, possesses strong immunomodulatory properties in subtoxic doses. Frondoside A stimulates lysosomal activity of mouse macrophages in vivo at a maximal effective stimulatory dose of 0.2 μg per mouse and is maintained over 10 days. This glycoside also shows a 30% stimulation of lysosomal activity in mouse macrophages in vitro at concentrations of 0.1–0.38 μg/mL. Frondoside A enhances macrophage phagocytosis of the bacterium Staphylococcus aureus in vitro at a maximal effective concentration of 0.001 μg/mL. Frondoside A stimulates reactive oxygen species formation in macrophages in vitro at a maximal effective concentration of 0.001 μg/mL. Frondoside A stimulates an increase in the number of antibody plaque-forming cells (normally B-cells in spleen) in vivo with a maximal stimulatory effect at a concentration of 0.2 μg per mouse (stimulatory index, 1.86). Frondoside A has a weak effec...