Melatonin in medicinal plants
In the early 1990s, melatonin became a popular supplement
for counteracting jet lag, helping people sleep, and for use as
an anti-cancer supplement. In 1995, an association between lower
levels of melatonin and migraine headaches was reported. The Canadian
researchers who conducted this study wondered if herbal products
used for treating insomnia, depression, migraine, and other nervous
system conditions might also contain melatonin [Murch et al.,
1997]. They began by testing the Canadian fewerfew migraine remedy
Tanacet® and leaf samples of what they called "green
leaf" and "gold leaf" feverfew (Tanacetum parthenium
[L.] Schultz-Bip., Asteraceae), in addition to flower and leaf
samples of St. John's wort (Hypericum perforatum L., Clusiaceae)
unidentified plant parts from skullcap (Scutellaria lateriflora
L., Lamiaceae), and unidentified plant parts from the calming
Chinese plant Huang-qin (Scutellaria baicalensis Georgi.,
Lamiaceae). No mention was made of the analytical method used
to detect melatonin.
All of the compounds tested contained melatonin. Huang-qin
yielded the highest concentration of melatonin (7.11 m
g/g), followed by St. John's wort flowers (4.39 m
g/g) and then fresh "green leaf" feverfew (2.45 m
g/g). The product Tanacet® contained little (0.57 m
g/g), and the lowest content of all was found in skullcap (0.09
m g/g).
The authors of the review concluded that "Melatonin
in plant tissues may explain ancedotal evidence of physiological
effects, but also emphasises the need for complete biochemical
characterisation of medicinal herbs." On the other hand,
ethnobotanist James Duke, PhD estimates that "it would take
pounds of material to provide an effective dose of 3 mg melatonin"
based on the levels of melatonin reported in this study. According
to Duke, in the case of S. baicalensis (the richest reported
source of melatonin), more than 60 g of plant material would have
to be consumed to achieve a 0.3 mg dose of melatonin.
Rob McCaleb, HRF
[Murch SJ, Simmons CB, Saxena PK. Melatonin in feverfew and other
medicinal plants. The Lancet 1997; 350: 1598-1599.]
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