Extension of life span and stress resistance of Drosophila melanogaster by long-term supplementation with melatonin.
According to the free radical theory of aging, free radicals are involved in the production of changes in cellular metabolism that lead to a time-dependent functional decline in all living beings. Consequently, antioxidant and/or free radicals scavengers may retard the aging process. We explored the effect of melatonin on the life span of Drosophila melanogaster (Oregon wild strain). It was presumed that given the antioxidant and free radicals scavenger properties of melatonin, this hormone would prevent oxidative damage to the fly tissues and slow down the process of aging. Melatonin, added daily to the nutrition medium at a concentration of 100 microg/ml, increased significantly the life span of D. melanogaster. The maximum life span was 61.2 days in controls and 81.5 days in melatonin fed flies. Relative to the controls, the percentage increase in the melatonin fed flies was 33.2% in maximum life span, 19.3% in the onset of 90% mortality, and 13.5% in median life span. Furthermore, in a test of superoxide mediated toxicity it was shown that melatonin treatment increased the resistance of D. melanogaster to paraquat. Finally, the augmented resistance to an ambient temperature of 36 degrees C was also a demonstration of the antioxidative protection provided by the hormone.
Bonilla
Ernesto
E
Instituto de Investigaciones Clínicas Dr Américo Negrette, Facultad de Medicina, Universidad del Zulia, Apartado Postal 1151 Maracaibo, Venezuela. ebonarillo@yahoo.com
Medina-Leendertz
Shirley
S
Díaz
Solangel
S
D000375:Aging / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000502:physiology*; D004351:Drug Resistance; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism; D008136:Longevity / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008954:Models, Biological; D018384:Oxidative Stress; D010269:Paraquat / Q000494:pharmacology; D013312:Stress, Physiological / Q000188:drug therapy / Q000503:physiopathology; D013696:Temperature
D000975:Antioxidants; D016166:Free Radical Scavengers; D005609:Free Radicals; D008550:Melatonin; D010269:Paraquat