A commonly prescribed anti-depressant increases the lifespan of worms
to the human equivalent of a centenarian, scientists looking for
chemicals that prolong longevity reported Wednesday.
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
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
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
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)