Phenylpropanoid NF-kB inhibitors from Bupleurum fruticosum

Two phenylpropanoids from Bupleurum fruticosum (Apiaceae/ Umbelliferae) were shown to inhibit the transcriptional activity induced by PMA or TNFα of an NF-κB-controlled reporter gene. Western blot experiments indicated that the phenylpropanoids did not prevent 1κBα degradation, suggesting that their molecular target is at a post-1KB degradation level. Both compounds prevented cytokine (IL-1, IL-6, TNF, IL-8) release and prostaglandin E₂ synthesis.