Could lithium medicine prolong your life?

The common mood-affecting drug, lithium, could double as an anti-ageing medication, according to a recent study in the online version of the Journal of Biological Chemistry.

The study found that nematode worms treated with lithium had an increase in lifespan of up to 46%, raising the tantalising question of whether humans taking the mood-affecting drug are also taking a possible 'elixir of life'.

Lithium is used by the pharmaceutical industry to treat mood affective disorders such as bipolar disease. While the drug has been shown to protect neurons, the underlying mechanism of its therapeutic action is not understood. In humans, lithium's therapeutic range is very limited and the drug has serious side effects.

"Lithium has been used to treat mood affect disorders, including bipolar, for decades," said Gawain McColl, senior research officer at the Mental Health Research Institute (MHRI) of Victoria and corresponding author of the study.

"Despite its successful clinical use, however, the mechanism of action in the brain still remains unclear."

In the study, researchers used a novel genetic approach to understand how lithium works and highlight the efficacy of using the nematode C. elegans as a research subject in the field of 'pharmacogenetics' - the study of genetic factors that influence an organism's reaction to a drug.

The researchers discovered that longevity was increased in the worms when the lithium 'turned down' the activity of a gene that modulates the basic structure of chromosomes.

The worms averaged a 36% rise in life expectancy, with some prolonging life by 46%.

"Understanding the genetic impact of lithium may allow us to engineer a therapy that has the same lifespan extending benefits (in humans)," said fellow author, Gordon Lithgow, of the Buck Institute in the US.

"One of the larger questions is whether the lifespan-extending benefits of the drug are directly related to the fact that lithium protects neurons. The process of normal ageing in humans is intrinsically linked to the onset of neurodegenerative disease.

"However, the cellular changes and events due to ageing that impact on neurodegeneration are not yet understood," he said.

Studies involving compounds such as lithium could provide breakthroughs in understanding the biomedical link between ageing and disease. The researchers are now surveying tens of thousands of compounds for affects on ageing.

The research highlights the success of using C. elegans as a model for studying drug toxicity and genetic impacts of chemical compounds.

"Studying genome-wide drug effects on gene activity is an extremely powerful and information-rich experiment system," said McColl.

"The simple nematode, Caenorhabditis elegans, has proven phenomenally successful as a model system to study the genetics of development and ageing. More recently, several informative models of neurodegenerative disease have also been developed in C. elegans, including models for Alzheimer's disease and Parkinson's disease.

"The numerous experimental advantages, including a fully sequenced genome, also make C. elegans very useful for both the investigation of how existing drugs work and for development of new therapeutics," he said.

"Ultimately, information gained using this relatively simple nematode will be translated into more complex vertebrate models."