Planta Med. 2001 Jun; 67(4): 364-6.

Inhibition of interleukin-12 production in lipopolysaccharide-activated mouse macrophages by hpyericin, an active component of Hypericum perforatum.

Kang BY, Chung SW, Kim TS.

Hypericin, an active component of Hypericum perforatum, was evaluated for the regulation of interleukin-12 (IL-12) production in mouse macrophages. Hypericin significantly inhibited IL-12 production in lipopolysaccharide-activated macrophages in a dose-dependent manner (IC50 = 1.45 micrograms/ml). Furthermore, hypericin potently inhibited the activation of IL-12 gene promoter, suggesting that hypericin negatively regulated IL-12 production at the transcription level. These results may explain some known biological activities of hypericin including its anti-rheumatic effect.