Effect of sub-chronic treatment with Jarsin (extract of St John's wort, Hypericum perforatum) at two dose levels on evening salivary melatonin and cortisol concentrations in healthy male volunteers.
OBJECTIVE
The aim of the present study was to measure the effect of two doses of extracts from Hypericum perforatum (HP), Jarsin, on evening salivary cortisol and NA-mediated melatonin in healthy male volunteers.


METHODS
Twenty healthy male volunteers were randomly given a low or high dose of Jarsin for 7 days. Saliva samples for cortisol and melatonin, and overnight urine samples were collected for cortisol and 6-sulfatoxymelatonin and measured by specific radioimmunoassays.


RESULTS
Treatment significantly increased salivary cortisol throughout the whole collection period in the low dose group but had no discernable effect in the high dose group. Salivary melatonin was not increased in either dose group following treatment.


CONCLUSIONS
Salivary cortisol was enhanced in the low dose group only and melatonin was not affected by either treatment. We suggest that HP may enhance salivary cortisol via a U-shaped dose-response relationship and that this may be mediated through a 5-HT2 mechanism.
Franklin
M
M
Molecular Neurosciences, BMS, Oxford Brookes University, Oxford, UK. michael.franklin@psychiatry.oxford.ac.uk
Hafizi
S
S
Reed
A
A
Hockney
R
R
Murck
H
H
D000328:Adult; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D020902:Hypericum; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D010865:Pilot Projects; D010936:Plant Extracts / Q000494:pharmacology; D011863:Radioimmunoassay; D012463:Saliva / Q000187:drug effects / Q000378:metabolism*
D010936:Plant Extracts; C054513:6-sulfatoxymelatonin; D008550:Melatonin; D006854:Hydrocortisone