Effects of compounds isolated from a Litsea japonica fruit extract on the TNF-α signaling pathway and cell viability

摘要

Tumor necrosis factor-α (TNF-α) plays an important role in inflammatory responses. Deregulated activation of TNF-α signaling is associated with various inflammatory diseases. In view of the finding that the seventy percent ethanol extract of Litsea japonica (LJE) interferes with TNF-α-induced NF-κB activation, activity- guided fractionation was performed to identify the active components of the extract. The EtOAc, CH₂Cl₂ and n-Hexane fractions of LJE induced suppression of inhibitor of κB (IκB) kinase (IKK), p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK), and significant reduction of TNF-α- induced NF-κB activation. From the CH₂Cl₂ fraction, hamabiwalactone A, hamabiwalactone B, litsenolide B2 and litsenolide C2 were identified to inhibit TNF- α-induced NF-κB activation. The cytotoxic activities of these lactone compounds were additionally evaluated.