Rapamycin is being heralded by some scientists as the first true anti-ageing drug. It works by inhibiting a gene called the mechanistic target of rapamycin, or mTOR for short. Inhibiting mTOR has shown to dramatically increase the lifespan of a number of organisms: yeast, worms and mice.
The story of rapamycins’ discovery is a fascinating one
On a snowy November day in 1964, a team of around 40 doctors and scientists boarded the Royal Canadian Navy’s H.M.C.S. Cape Scott in Halifax, Nova Scotia. They were headed to Easter Island, a tiny speck in the South Pacific that’s 2,200 miles from its nearest inhabited neighbour. A island known for its iconic Maui ‘head’ statues.
The initial purpose of the expedition was to investigate the prevalence of tetanus, a bacterial infection, amongst the indigenous people of the island. The number of cases of this infection, on the island, was remarkably low considering they wore no footwear around the island, and used horses as their main mode of transport (horse manure is a fertile breeding ground for tetanus spores).
The team, led by Georges Nógrády, an eastern European microbiologist, collected a number of soil samples from around the island to take home to study the bacterial spores.
The study was relatively unsuccessful in its initial aim, as only a single soil sample contained any of spores that they were hoping to isolate. However, not to waste perfectly good soil samples from such an isolated part of the world, Georges passed the samples onto a research team at Ayerst Pharmaceuticals, now known as Pfizer.
After years of painstaking work isolating and analysing the samples, the researchers identified a new microbe, a bacterium called Streptomyces hygroscopicus, which produced a compound that would kill any fungus it came into contact with.
This compound was dubbed rapamycin after the indigenous name of Easter Island, Rapa nui, the island on which it was discovered.
It was quickly realised that rapamycin could suppress the immune system, leading to it becoming an FDA approved drug for pre-transplant immunosuppression.
In 2009, a serendipitous breakthrough found that rapamycin administration resulted in profound life-extending properties in elderly mice (28% extension in males, 38% extension in females).
This has led to a plethora of studies looking at rapamycin as an anti-ageing intervention, which will hopefully, provide some very promising results in the near future!