A TRANSPLANT drug with
anti-ageing 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 rejuvenate oral health, says
team leader Matt Kaeberlein at
the University of Washington in
Seattle. “We could actually
see spots where new bone was
growing around the teeth.”
Two-thirds of elderly
people have gum disease and
no existing treatment reverses
the process, says Kaeberlein.
What’s more, gum disease is
linked to a higher risk of other
conditions, including dementia,
diabetes and heart disease.
Some researchers think gum
disease may cause Alzheimer’s,
as New Scientist reported earlier
this year (see page 26). This
suggests that restoring oral
health could have much wider
benefits. “It’s clear to me that
this could be immensely
important,” says Kaeberlein.
But it isn’t clear if rapamycin
has the same effect in humans.
Even if it does, the drug can have
many undesirable side effects.
It 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 several animals, including
mice and fruit flies, by around
10 per cent. Kaeberlein started
looking at its effect on the
mouth when Jonathan An,
who 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 – elderly in
mouse terms – 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 the mice’s mouths, as well as
a decline in disease-associated
bacteria that become more
common in older animals
(bioRxiv, doi.org/dgzq). These
include Porphyromonas
gingivalis, which is a suspected
cause of Alzheimer’s.The findings are fascinating,
says João Pedro de Magalhães,
at the University of Liverpool,
UK. “The big question is whether
it could have the same effect in
people,” he says.
Several groups are creating
variants of rapamycin that
are 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 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’t 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. ❚21/28 December 2019 | New Scientist | 9A BRONZE AGE painting on a
Greek island shows a monkey
from thousands of kilometres
away in Asia. The finding suggests
that ancient cultures separated by
great distances were trading and
exchanging ideas.
The artwork is one of several
wall paintings in a building at
Akrotiri on the Greek island
of Santorini in the Aegean Sea.
Akrotiri was a settlement of the
Minoan civilisation in Bronze
Age Greece that was buried by
ash from a volcanic eruption in
around 1600 BC.
Many of the paintings show
monkeys, yet there were none in
Greece at the time. Most are species
also found in Ancient Egyptian
art like olive baboons. This makes
sense as Egypt was in contact with
the Minoan civilisation, which
was spread across several Aegean
islands. However, others were
harder to identify.
Marie Nicole Pareja at the
University of Pennsylvania in
Philadelphia teamed up with
primatologists to re-examine theArt hints that ancient
Greeks travelled far
ArchaeologyMichael MarshallMI
LA
N^ GONDA
/^ ALA
MYSTOCK^ PHOTOmystery monkey paintings. One
stood out. “When they looked at
this wall painting, they all straight
away unambiguously said ‘that’s a
langur’,” says Pareja. The team has
identified the monkey as a grey
langur. As well as its distinctive
fur, the monkey was depicted
holding its tail in a characteristic
S shape (Primates, doi.org/dgv9).
Grey langurs live in southern
Asia in what is now Nepal, Bhutan
and India – and particularly in the
Indus Valley. During the Bronze
Age, the region was home to the
Indus Valley Civilisation. The artist
who painted the picture must
somehow have seen a grey langur.
Did Minoan Greeks visit the
Indus? “I wouldn’t be surprised if
someday in the future we found
evidence for that kind of direct
contact,” says Pareja, but right now
there is none. It is also possible the
visit was the other way round, but
again there is no evidence.
Instead, it may be that the two
civilisations were connected via
Mesopotamia, another Bronze
Age civilisation centred on what
is now Iraq. Langurs may have
been imported to Mesopotamia
for menageries, where visiting
Greeks saw them. ❚Grey langur monkeys
painted at Akrotiri on the
Greek island of SantoriniHealth
Michael Le Page
Mouse mouths
restored with
anti-ageing drug
“ We could actually
see spots where new
bone was growing
around the teeth”