Geroprotector effectiveness of melatonin:: investigation of lifespan of Drosophila melanogaster

The lifespan (LS) of Drosophila melanogaster was studied under the effect of melatonin at a concentration of 0.08% selected in preliminary experiments. The compound was introduced into a culture medium only at the stage of development. An inverse relationship was observed between the change in LS after the impact of the preparation and the value of LS in the corresponding control group (Spearman's rank correlation coefficient R = -0.83, P < 0.02). For a relatively low LS in a population from which the control and experimental groups were formed, the geroprotector effect of melatonin is the most distinct; for a relatively high LS, the effect of the hormone is either not detected or appears as a toxic reduction in LS (up to 10%) in the experimental group. Such nonuniform effects of melatonin are connected with fluctuating changes in viability in successive generations of D. melanogaster. The antioxidant mechanism of the geroprotector effect is also discussed. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.