Feverfew Extracts and the Sesquiterpene Lactone Parthenolide Inhibit Intercellular Adhesion Molecule-1 Expression in Human Synovial Fibroblasts

Previous studies have shown that extracts of the aromatic herb feverfew (Tanacetum parthenium) and one of its bioactive components, parthenolide, have anti-inflammatory properties in vivo and in vitro. We examined both crude feverfew extracts and purified parthenolide for their ability to modulate adhesion molecule expression in human synovial fibroblasts. Pretreatment of synovial fibroblasts with either feverfew extracts or purified parthenolide could inhibit the expression of intercellular adhesion molecule-1 (ICAM-1) induced by the cytokines IL-1 (up to 95% suppression), TNF-alpha (up to 93% suppression), and, less strongly, interferon-gamma (up to 39% suppression). Inhibition of ICAM-1 was dose and time dependent; as little as a 30-min pretreatment with feverfew resulted in inhibition of ICAM-1. The decrease in ICAM-1 expression was accompanied by a decrease in T-cell adhesion to the treated fibroblasts. Other herbal extracts with reported anti-inflammatory effects were similarly tested and did not decrease ICAM-1 expression. The modulation of adhesion molecule expression may be an additional mechanism by which feverfew mediates anti-inflammatory effects.