Inhibition of substance P-induced cytokine synthesis by St. John's wort extracts

Pharmacopsychiatry. 2001 Jul;34 Suppl 1:S26-8. doi: 10.1055/s-2001-15462.


We tested the hypothesis that extracts from St. John's wort interfere with protein synthesis induced by substance P (SP), a neuropeptide which has been implicated in the etiopathology of depression and anxiety. Using human astrocytoma cells, which express functional neurokinin (NK)-1-receptors, we investigated whether extracts from St. John's wort are able to inhibit SP-induced synthesis of the cytokine interleukin-6 (IL-6). We found a potent and dose-dependent inhibition of SP-induced IL-6 synthesis by various extracts from St. John's wort. These results do not only give further evidence of the anti-inflammatory effects of St. John's wort, but also lend support to the hypothesis that the antidepressant effect of St. John's wort is, at least in part, a result of its inhibitory effects on SP-induced protein synthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antidepressive Agents / pharmacology*
  • Astrocytoma
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Hypericum*
  • Interleukin-6 / biosynthesis*
  • Plant Extracts / pharmacology*
  • Substance P / metabolism*
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / metabolism


  • Antidepressive Agents
  • Interleukin-6
  • Plant Extracts
  • Substance P