Effects of Exogenous Melatonin—A Review

Abstract

The results of studies on the effect of pineal indole hormone melatonin on the life span of mice, rats, fruit flies, and worms are critically reviewed. In mice, long-term administration of melatonin was followed by an increase in their life span in 12 experiments and had no effect in 8 of 20 different experiments. In D. melanogaster, the supplementation of melatonin to the nutrient medium during developmental stages gave contradictory results, but when melatonin was added to food throughout the life span, an increase in the longevity of fruit flies has been observed. Melatonin decreased the survival of C. elegans but increased the clonal life span of planaria Paramecium tertaurelia. Available data suggest antioxidant and atherogenic effects of melatonin. Melatonin alone turned out to be neither toxic nor mutagenic in the Ames test and revealed clastogenic activity in high concentration in the COMET assay. Melatonin inhibits mutagenesis induced by irradiation and by indirect chemical mutagens and inhibits the development of spontaneous and chemical-induced tumors in mice and rats. Further studies and clinical trials are needed to verify that melatonin is both safe and has geroprotector efficacy for humans.

Caloric restriction versus drug therapy to delay the onset of aging diseases and extend life

“…CR has a general antiaging effect, whereas the drugs have specific effects, each acting mainly on one disease or pathological process. A number of chemical agents (Masoro 2002c;Bernarducci and Owens 1996;Ingram et al 2004) may be CR mimetics in experimental animals since they alter the aging rate or extend life, such as 2-deoxyglucose (Lane et al 2002;Ingram et al 2004), antioxidants (Bernarducci and Owens 1996) deprenyl (Kitani et al 2000), melatonin (Anisimov 2003a), carnosine (Hipkiss et al 2001) coenzyme Q10 (Linnane et al 2002), dehydroepiandrosterone (DHEA) (Nawata et al 2002;Percheron et al 2003), epitalon ), antidiabetic biguanides ) and metformin , resveratol (Howitz et al 2003), and a combination of acetyl-L-carnitine and lipoic acid (Hagen et al 2002).…”

Intensity of In Vitro Incorporation of 3H-Melatonin in the Thyroid Gland of Rabbits with Pineal Gland Hypofunction

“…This hormone not only prolongs the life span [4,5], but also reduces the toxicity and stimulates the effi ciency of other drugs in combined therapy [7]. It remains unclear whether the capacity of TG (weakened in hypofunction of the pineal gland) to bind circulating melatonin is unchanged.…”

“…These data suggested that the initial stage of hypothyroidism, or the so-called "latent hypothyroidism", was detected during that period. Simultaneous measurement of free thyroid hormones would have been more informative in this aspect, but we failed to fi nd these data in published reports.Melatonin defi ciency in hypofunction of the pineal gland is corrected by substitution therapy [4,5]. This hormone not only prolongs the life span [4,5], but also reduces the toxicity and stimulates the effi ciency of other drugs in combined therapy [7].…”

“…Melatonin defi ciency in hypofunction of the pineal gland is corrected by substitution therapy [4,5]. This hormone not only prolongs the life span [4,5], but also reduces the toxicity and stimulates the effi ciency of other drugs in combined therapy [7].…”

Analysis of 5-Methyltryptamine,L-Tryptophan, 5-Hydroxy-L-Tryptophan, and Melatonin in the Bulbs of Garlic by Thin-Layer Chromatographic Method Coupled with Densitometric Detection

“…Serotonin also has some cognitive functions, including memory and learning [22]. Melatonin is a strong antioxidant, delays the ageing processes, neutralizing free radicals, such as the hydroxyl radical, so melatonin may reduce the damage caused by some types of Parkinson's disease [23,24]. There have also been studies proving its efficacy in the treatment of Alzheimer's disease.…”