The Extract of Chrysanthemum Indicum Linne Inhibits EBV LMP1-induced NF-κB Activation and the Viability of EBV-transformed Lymphoblastoid Cell Lines

Epstein-Barr virus (EBV) latent infection transforms B lymphocytes into proliferating lymphoblastoid cell lines (LCLs). EBV latent infection membrane protein 1 (LMP1) is required for EBV-mediated B lymphocyte transformation, and LMP1-induced NF-κB activation is essential for LCL survival. To identify a novel inhibitor candidate for LMP1-induced NF-κB activation, crude ethanol extracts of medicinal plants were screened for the potential NF-κB inhibitory activity. Seventy percent ethanol extract of Chrysanthemum indicum Linne extract (CIE) strongly reduced LMP1-induced NF-κB activation. In addition, CIE inhibited LMP1-induced IKKα or IKKβ activation. Interestingly, CIE treatment rapidly reduced LCL viability without exhibiting any adverse effects on the viability of human foreskin fibroblasts (HFF), EBV negative Burkitt's lymphoma cell lines (BL41) or HeLa cells. Taken together, CIE has potent inhibitory effect on EBV LMP1-induced NF-κB activation and EBV-transformed LCL viability.