Effects of exogenous melatonin--a review

Area of Science:

• Gerontology
• Endocrinology
• Toxicology

Background:

• Pineal indole hormone melatonin is studied for its potential effects on aging.
• Previous research shows varied impacts of melatonin on lifespan across different species.

Purpose of the Study:

• To critically review existing studies on melatonin's effect on lifespan in various organisms.
• To assess melatonin's safety and potential geroprotective efficacy.

Main Methods:

• Literature review of studies involving mice, rats, fruit flies (D. melanogaster), worms (C. elegans), and planaria (Paramecium tertaurelia).
• Analysis of data from lifespan experiments, Ames test, and COMET assay.
• Examination of melatonin's effects on induced mutagenesis and tumor development.

Main Results:

• Melatonin increased lifespan in some mouse studies but not others.
• Inconsistent effects were observed in fruit flies and worms; increased lifespan in planaria.
• Melatonin showed antioxidant and atherogenic effects, was non-toxic/mutagenic in Ames test, but clastogenic at high concentrations.
• It inhibited mutagenesis and tumor development in rodents.

Conclusions:

• Melatonin's impact on lifespan is species-dependent and context-specific.
• While showing some promise in inhibiting mutagenesis and tumors, further research is needed.
• Clinical trials are required to confirm melatonin's safety and geroprotective benefits for humans.