- People who take the popular supplement
melatonin hoping for antioxidant or sleep benefits may be getting more
than they bargain for, according to Louisiana State University chemists.
Their newly released findings show melatonin reacts with chemicals in the
body to form compounds that could alter behavior.
- Details about the research will appear
in the peer-reviewed journal Chemical Research in Toxicology, published
by the American Chemical Society (ACS), the world's largest scientific
society. The paper will become available on the ACS Web May 26 and is tentatively
scheduled to be in the journal's June 14 print edition.
- Melatonin is produced naturally by the
body to control sleep cycles, but is needed in only very low concentrations.
It is sold as a sleeping aid and as an antioxidant. However, chemists William
A. Pryor and Giuseppe L. Squadrito of the university's Biodynamics Institute
say that the antioxidant properties of melatonin are very modest at best
and that metabolizing excess melatonin may cause more harm than good. "It
is our hypothesis," says Squadrito, "that secondary products
of melatonin have as yet unrecognized health effects."
- The scientists found that carbonate and
nitrogen dioxide radicals, which are constantly formed in the human body
from peroxynitrite, react with melatonin to form two cyclic metabolites
that resemble brain signaling chemicals but whose biological function is
unknown. "Our kinetic modeling, using competitive reactions, indicate
that the reaction of melatonin with peroxynitrite-derived free radicals
is physiologically important," states Squadrito adding that it "becomes
even more important when taking melatonin as a supplement."
- While admitting that it is unclear how
increased amounts of the neurotransmitter-like metabolites impact health,
Squadrito theorizes that "they could have an important effect on aspects
of behavior...like mood."
- All of these experiments were conducted
within laboratory equipment. Squadrito says future studies are needed to
measure the compounds within the human body and determine whether there
is a correlation between their levels and any health problems.
- A nonprofit organization with a membership
of nearly 159,000 chemists and chemical engineers, the American Chemical
Society publishes scientific journals and databases, convenes major research
conferences, and provides educational, science policy and career programs
in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.
- Note: This story has been adapted from
a news release issued by American Chemical Society for journalists and
other members of the public. If you wish to quote from any part of this
story, please credit American Chemical Society as the original source.
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