A transplant drug with anti鈥慳geing properties has been shown to rejuvenate the oral health of old mice. The drug, called rapamycin, regenerated the bone in which teeth are embedded, restored the mouth microbiome to a youthful state and reduced inflammation.
It is the first time any treatment has been shown to聽rejuvenate oral health, says team leader Matt Kaeberlein at the University of Washington in Seattle. 鈥淲e could actually see聽spots where new bone was growing around the teeth.鈥�
Two-thirds of elderly people聽have gum disease and no聽existing treatment reverses the聽process, says Kaeberlein. What鈥檚 more, gum disease is linked to a聽higher risk of other conditions, including dementia, diabetes and heart disease.
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Some researchers think gum disease is the cause of Alzheimer鈥檚, as 快猫短视频 reported earlier this year. This suggests that restoring oral health could have much wider benefits. 鈥淚t鈥檚 clear to me that this could be immensely important,鈥� says Kaeberlein.
But it isn鈥檛 clear if rapamycin has the same effect in humans. Even if it does, the drug can have many undesirable side effects. It聽suppresses the immune system, which is why its main use is in preventing transplanted organs from being rejected.
Rapamycin has also attracted interest for its anti-ageing effects: it can extend the lives of聽several animals, including mice聽and fruit flies, by around 10聽per cent. Kaeberlein started looking at its effect on the mouth when Jonathan An, who聽had previously studied dentistry, joined his team.
The researchers found that mice given rapamycin all their lives had more bone around their teeth. So they gave mice aged 20 months聽鈥� elderly in mouse terms聽鈥� food with added rapamycin for eight weeks, and compared their oral health with that of mice not given the drug.
The team saw bone growth in聽the mice鈥檚 mouths, as well as a decline in disease-associated bacteria that become more common in older animals. These include Porphyromonas gingivalis, which is a suspected cause of Alzheimer鈥檚.
The findings are fascinating, says Jo茫o Pedro de Magalh茫es, at the University of Liverpool, UK. 鈥淭he big question is whether it could have the same effect in people,鈥� he says.
Several groups are creating variants of rapamycin that are聽designed to minimise undesirable effects, and some are being trialled in people.
It is possible these drugs will have the same benefits for oral health that were seen in mice.
Kaeberlein is carrying out another mouse study designed to reveal if applying rapamycin just to the mouth, rather than to聽the entire body, has the same effect. He also hopes to run a trial in people. Using a lower dose than that given to people with transplanted organs might minimise side effects, he says.
He doesn鈥檛 plan to study those already on the drug. People needing transplants are seriously ill and are given many different drugs, so there are too many confounding factors, he says.
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