Hypericin as a non-antioxidant inhibitor of NF-kappa B

NF-kappa B is a transcription factor involved in immune and inflammatory re sponses. Here we show that micromolar concentrations of hypericin inhibited the PMA- and TNF-alpha-induced activation of NF-kappa B in Hela and TC10 c ells, respectively. In contrast, NF-kappa B activated by H2O2 was not influ enced by hypericin, indicating a pathway-specificity of hypericin. Hyperfor in and a Hypericum perforatum extract standardised on 0.15% hypericin and 5 % hyperforin were not active at pharmacologically relevant concentrations. The PMA/TNF-alpha-induced transcription of a reporter gene, which is under the control of the NF-kappa B-dependent IL-6 promoter, was strongly reduced by preincubation with hypericin.