title: [Bioassay-guided fractionation of constituents targeting mediators of inflammation from lycii cortex as inhibitors of NF-kappaB].
abstract: Lycii Cortex, a popular herb medicine in traditional Chinese medicine, is used to treat different inflammation-related diseases. The aim of our work is to find the key constituents inhibiting NF-kappaB, a key regulator of inflammation. In the investigations of cell-based in vitro assays of extracts, we found that both ethyl acetate extract and methanol extract of Lycii Cortex inhibited the TNF-alpha-induced activation of NF-kappaB. Through bioassay-guided fractionation, we identified 4 phenolic amides including trans-N-(p-coumaroyl) tyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), and dihydro-N-caffeoyltyramine (4). Four phenolic amides showed differently inhibitory activities on TNF-alpha-induced NF-kappaB activation. Trans-N-caffeoyltyramine (3) was identified as the key component with an IC50 of 18.41 micromol x L(-1). It was suggested that the hydroxyl group at C-3 in trans-N-caffeoyltyramine might be a key binding site and its C-7,8-double bond might play an important role on NF-kappaB inhibitory activities as the link of the conjugation of pi electrons leading to a partial planar conformation. It might be inferred that the biological activity of compound 3 is attributed to the structure of Michael reaction acceptor containing alpha, beta-unsaturated ketones and benzene along with hydroxyl group in o-diphenol.
authors.forename: Lian-Wu
authors.initials: LW
authors.lastname: Xie
authors.forename: Shun-Xiang
authors.initials: SX
authors.lastname: Li
authors.forename: Yu-Xia
authors.initials: YX
authors.lastname: Xie
authors.forename: Yu
authors.initials: Y
authors.lastname: Pan
authors.forename: Rong
authors.initials: R
authors.lastname: Yu
authors.forename: Xi-Hua
authors.initials: XH
authors.lastname: Cheng
mesh_terms: D001681:Biological Assay; D002460:Cell Line; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D018836:Inflammation Mediators / Q000037:antagonists & inhibitors* / Q000276:immunology; D032305:Lycium / Q000737:chemistry*; D015394:Molecular Structure; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000276:immunology
chemical_list: D004365:Drugs, Chinese Herbal; D018836:Inflammation Mediators; D016328:NF-kappa B