Inhibition of substance P-induced cytokine synthesis by St. John's wort extracts.
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.
Fiebich
B L
BL
Department of Psychiatry, University of Freiburg Medical School, Germany. bernd_fiebich@psyallg.ukl.uni-freiburg.de
Höllig
A
A
Lieb
K
K
D000928:Antidepressive Agents / Q000494:pharmacology*; D001254:Astrocytoma; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D020902:Hypericum; D015850:Interleukin-6 / Q000096:biosynthesis*; D010936:Plant Extracts / Q000494:pharmacology*; D013373:Substance P / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D000928:Antidepressive Agents; D015850:Interleukin-6; D010936:Plant Extracts; D013373:Substance P