A phenylpropanoid glycoside acteoside was found to induce interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha) in macrophage-like cell line J774.A1 at 1-100 ng/ml. In addition, when the stimulatory action of acteoside was studied using the bovine glomerular endothelial cell line GEN-T, it stimulated IL-6 production. These stimulatory activities were not abolished by treatment with polymixin B, which inactivates lipopolysaccharide (LPS), indicating that the action was not a contamination of LPS.