What determines lifespan remains poorly understood, but a spate of recent research has begun to unlock mechanisms that could one day add years and extra pep to the human endgame.
In humans, the anti-depressant mianserin prevents the neurotransmitter serotonin from being reabsorbed once it has been released by nerve cells in the brain, thus extending its impact.
Decreased levels of serotonin, a naturally occurring chemical that creates a feeling of well-being, have been linked in many studies to depression.
Linda Buck, a researcher at the Howard Hughes Institute in Seattle, Washington, and two colleagues screened 88,000 chemicals to see which might enhance the lifespan of Caenorhabiditis elegans, a short-lived worm commonly used in experiments on longevity.
Extends life by 30 percent
In the experiments, a chemical virtually identical to the drug
mianserin extended the lives of worms by 30 percent, according to the
study.
Three other compounds that also act on serotonin also had a similar effect: mirtazapine, methiothepin and cyproheptadine.
The antidepressant notably blocked uptake of another neurotransmitter, octopamine, which has a role in releasing fat from fat cells.
This links to previous studies showing that lab animals which were kept on a low-calorie diet live longer, said Buck, who won the 2004 Nobel for medicine for research on the human olfactory system.
The findings are not proof that anti-depressants can extend life in humans. Rather, they shed light on some of the molecular pathways in the ageing process, say the authors.
"Lifespan can be extended by blocking certain types of neurotransmission implicated in food sensing in the adult animal," Buck said. – (Sapa/AFP)
Read more:
Anti-ageing breakthrough
Anti-ageing Centre