Velutin, a natural product isolated and purified from the leaves of Vernonia flexuosa with anti-inflammatory property, exhibits the greatest potency among all flavones in reducing TNF-α and IL-6 production and shows the strongest inhibitory effect in nuclear factor (NF)-κB activation and exhibits the greatest effects in blocking the degradation of inhibitor of NF-κB as well as in inhibiting mitogen-activated protein kinase p38 and JNK phosphorylation.