Hypericum perforatum inhibits the binding of mu- and kappa-opioid receptor expressed with the Semliki Forest virus system.
The effects of Hypericum perforatum extracts on in vitro [3H]naloxone binding to the human mu- and rat kappa-opioid receptors were studied in chinese hamster ovary (CHO) cells using the Semliki Forest virus (SFV) expression system. Binding of [3H]naloxone to the mu- and kappa-opioid receptor was inhibited in the presence of Hypericum extracts showing IC50 values of approximately 25 and 90 micrograms/ml, respectively. In contrast, extracts of Valeriana officinalis did not inhibit binding to the mu-opioid receptor. Also, single constituents of H. perforatum like the flavonoids quercetin and kaempferol and the glycosilated flavonoid quercitrin did not inhibit [3H]naloxone binding to the mu-opioid receptor up to a concentration of 10 microM. The present in vitro data may suggest a new possible mechanism for the anti-depressant effect of H. perforatum.
Simmen
U
U
Dept. of Pharmaceutical Biology, University of Basel, Switzerland.
Schweitzer
C
C
Burkard
W
W
Schaffner
W
W
Lundstrom
K
K
D000818:Animals; D016466:CHO Cells / Q000378:metabolism; D006224:Cricetinae; D006801:Humans; D009270:Naloxone / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal; D051381:Rats; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D012672:Semliki forest virus / Q000235:genetics* / Q000378:metabolism*
D010936:Plant Extracts; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D009270:Naloxone