Links To Other Anti-Aging Therapies
Since melatonin plays such a central role in so many of the body's life maintenance processes, and is found so ubiquitously throughout the body, one wonders whether the health and longevity benefits of other therapies might be mediated through their interaction with melatonin.
Does Deprenyl Stimulate Melatonin Synthesis?
It's long been assumed that low doses of deprenyl--according to the rat experiments of Hungarian scientist Dr. Joseph Knell-- (injections of 0.25 mg/kg every other day) inhibit the enzyme monoamine oxidase-B (MAO-B) selectively, and that this selective inhibition is lost at higher doses, which also inhibit monoamine oxidase-A (MAO-A). It's also been assumed that deprenyl's ability as a selective inhibitor of MAO-B is at least partially responsible for its ability to extend lifespan in both laboratory animals and Parkinson's Disease patients.
This hypothesis is based upon 21day studies of low and high doses of deprenyl in rats. However, a recent study at the Brown University School of Medicine in Providence, Rhode Island showed that, after six months of low-dose deprenyl treatment in rats, deprenyl inhibited both MAO-B and MAO-A!
This inhibition doubled the concentration of serotonin in the pineal gland of the deprenyl-treated rats, increased the levels of noradrenaline, and doubled the levels of the metabolic precursor to melatonin (N-acetylserotonin) , although there was no evidence of increased melatonin levels. Since melatonin is manufactured from serotonin in the pineal gland triggered by noradrenaline, these findings suggest that long-term deprenyl therapy may slow aging and extend lifespan by stimulating the synthesis of melatonin!
Does Acetyl-l-Carnitine Stimulate Melatonin Synthesis?Scientists at the University of Milan in Italy have found that injections of acetyl-l-carnitine (ALC) at doses of 10, 30, and 90 mg/kg lead to "remarkable increases" of pineal and serum melatonin one hour later in young (2 month-old) male rats, but that only the 90 mg/kg dose of ALC increases melatonin levels in old (24 month old) rats.
The scientists hypothesize that:
"Since both ALC and melatonin are remarkable free radical scavengers, it is possible that ALC's ability to reverse certain aging processes may be due to its ability to promote melatonin production. Another reasonable hypothesis that can be derived from this study is that the body may lose its ability to utilize acetyl-l-carnitine and that we may need to take higher doses of ALC to Compensate for this age-related change. "
Melatonin Increases Growth Hormone Levels
When scientists at the University of Manitoba in Canada gave hamsters daily injections of melatonin for 10 weeks they found a "substantial increase" of both growth hormone and insulin-like growth-factor-1 (IGF-1)--a precursor to growth hormone. These findings suggest that one of melatonin's mechanisms of action in promoting longevity may be the stimulation of growth hormone release. Growth hormone is depleted with advancing age (just as melatonin is), and the administration of growth hormone to aging men has produced rejuvenation effects such as increased muscle mass, increased strength, greater flexibility, and better coordination.