Address for correspondence: Prof. G.F. Oxenkrug, M.D., Ph.D., Pineal Research Laboratory, Department of Psychiatry, St. Elizabeth's Medical Center, QN-3P, 736 Cambridge St., Boston, MA, 02135, U.S.A. Voice: 617-789-2925; fax: 617-789-2066.
goxenkrug{at}cchcs.org
It is generally accepted that antioxidant properties of melatonin
significantly contribute to its antiaging effect. Antioxidant
effects of
N-acetylserotonin (NAS), a melatonin precursor and
metabolite, might predict its antiaging action as well. The
antiaging effect of NAS was studied in female retired breeders
and male C3H mice. Both NAS and melatonin administered with
drinking water prolonged life span in male animals by about
20% versus control animals (
p < 0.01) but did not affect
the life span of female mice. Antioxidative activity was evaluated
by determining the malonaldehyde + 4-hydroxynonenal (MDA + 4-HNE)
and cellular glutathion peroxidase (GPx) levels in male, 11-month-old,
C57Bl/6J mice with very limited (if any) capacity to convert
pineal NAS into melatonin. NAS increased the antioxidant capacity
of kidney. Both NAS and melatonin (four weeks daily i.p. injections)
increased the antioxidant capacity of brain as demonstrated
by decreased MDA + 4-HNE and increased GPx levels. NAS-treated
C57Bl/6J mice experienced a weight loss of 9%, whereas the saline
and melatonin groups only 3%. NAS- and melatonin-treated animals
had healthy and luxuriant fur coats with some gray fur in the
melatonin group; animals in the saline group had large areas
of baldness. This study demonstrates, for the first time, the
antiaging effect of NAS. This effect needs to be confirmed in
animals with impaired capacity to convert NAS into melatonin.
