And the bacterial beginnings of a possible canine life-extender
Even when it’s been painstakingly explained to us that Easter Day usually falls on “the first Sunday after the first Full Moon occurring on or after the March equinox,” we’re frankly, none the wiser.
Maybe you’re similarly at sea.
So we can happily reassure you that this year’s Easter Sunday is indeed this coming weekend – April 16th.
However, while you may be looking forward to chomping chocolate in good company over the weekend, spare a thought for Dutch explorer Jacob Roggeveen, who spent his Easter Sunday almost 300 years ago (in 1722) becoming the first recorded European to set foot on one of the world’s most remote inhabited islands, in the south-eastern Pacific Ocean.
At the time, the island was known as Rapa Nui, but thanks to the day on which Roggeveen got there, it was henceforth to be known as Easter Island.
Thank goodness he didn’t get there on National Donut Day, eh?
Easter Island is more than 2,000 miles away from the nearest continental land mass, in Chile, and is of course best known for its 887 monumental statues called Moai, carved from stone by the early Rapa Nui people.
The island currently has around 6,600 inhabitants, whose relative isolation has long made them of interest to scientists, and in 1964 a group of Canadian researchers travelled there to study the locals’ health.
The scientists also collected various biological specimens, including soil samples, with little idea that they’d later find the samples contained the equivalent of hidden gold.
You see, ten years after their visit, the Canadians announced they’d identified a bacterium in the Easter Island soil that secreted an entirely new antibiotic compound, which they named rapamycin, after the island’s original name.
This bacterium was Streptomyces hygroscopius, and its antibiotic by-product proved highly active against Candida species, particularly Candida albicans – which causes an infection in humans commonly known as thrush.
However, rapamycin went on to have a catalog of useful and quite unexpected properties.
We’ll leave the most extraordinary for last.
Soon after its discovery, it was learned that rapamycin’s ability to suppress the immune system made it amazingly useful for transplant patients, preventing them from rejecting their new organs.
The next bombshell was learning that rapamycin can stop cells dividing, leading to it forming the basis of potential anti-cancer drugs such as Temsirolimus.
But perhaps its most fascinating property of all was announced in a 2009 letter to Nature, which explained that mice fed with capsules containing rapamycin had experienced lifespans extended by 9-14%.
To place this in perspective, the study’s lead scientist, David Harrison, said: “By comparison, preventing all atherosclerosis [hardening of the arteries] AND cancer deaths in humans would increase lifespans by less than 9%.”
Now, before we go one single mouse-whisker further, it’s absolutely vital to note that rapamycin is unquestionably NOT a drug that anyone should take as a life-extender because, as we’ve explained, it suppresses the immune system.
And unfortunately this means it gives with one hand and takes away with the other.
Indeed, as David Harrison noted: “It may do more harm than good.”
Nevertheless, the research on mice delivered remarkable results, particularly when you learn that the study involved what you might term a happy accident.
The experiment was part of the National Institute on Aging Interventions Testing Program, which specifically tests diets, drugs, or other interventions to see if they can prevent disease and extend life in mice.
Anyone can suggest an intervention, and during the program’s existence, it has also examined green tea extract, aspirin, resveratrol (from red wine), and simvastatin as other possible mouse life-extenders.
Believing they were about to start immediate experimentation, David Harrison’s team assembled their mice, but then they realised they would need to enclose the rapamycin in capsules in order to enable it to pass intact through the mice’s acidic stomach conditions before arriving in their guts.
Like all these things, it took about a year to organise that, which meant the mice were already 20 months-old when they began consuming rapamycin.
Now, 20 months in mouse-years is the equivalent of a 60 year-old human, so this gave the rapamycin a chance to show that it was able to extend lifespan even when administered relatively late in life.
Rapamycin works by blocking a single protein – an enzyme known as TOR (target of rapamycin) – which is the first protein that has been shown to influence lifespan in all four of the model species that scientists commonly use to study aging: yeast, worms, flies, and mice.
Work to explore rapamycin’s effect on aging continues, with a growing body of research.
And there’s a particularly poignant study called the “Dog Aging Project” running at the University of Washington, which is exploring rapamycin as a possible way to extend the lifespan of dogs, recognizing the profound bond that develops between people and their pets.
A small phase I study has shown no significant side-effects associated with the rapamycin treatment, but as yet has also found no evidence that aging is slowed.
Researchers are optimistic, however, about a larger, longer phase II study.
It’s a long way from Seattle to Easter Island (5,222 miles to be precise).
But it’s heart-warming to learn of this connection between Easter Island, and the longevity of man’s, and woman’s, best friend.