We have identified Helioxanthin, a naturally occurring lignan from Taiwania cryptomerioides to have profound inhibition of hepatitis B virus gene expression and replication in human hepatoma cells. Heliothanxin also showed anti-inflammatory activity in human hepatoma cells. In the present study we looked into its anti-inflammatory mechanism of inhibition. Heliothanxin inhibited TNF α and IL1-induced transcriptional activity of NF-κB by the promoter/luciferase reporter gene in HuH7 cells. It also inhibited the TNF α -induced DNA binding of nuclear NF-κB but not the phosphorylation and degradation of IK κB by the EMSA assay and Western blotting respectively in HuH7 cells. Moreover, heliothanxin did not inhibit the TNF α -induced nuclear translocation of p65, a component of NF-κB by Western blotting. These results indicate that heliothanxin is a potent inhibitor of NF-κB activation and may further develop as a useful anti-inflammatory agent.

[Proc Amer Assoc Cancer Res, Volume 47, 2006]