Newswise, April 20, 2017— Antibiotics save lives every day,
but there is a downside to their ubiquity. High doses can kill healthy cells
along with infection-causing bacteria, while also spurring the creation of
“superbugs” that no longer respond to known antibiotics.
Now, researchers may have found a natural way to cut down on
antibiotic use without sacrificing health: a maple syrup extract that
dramatically increases the potency of these medicines.
The researchers will present their work at the 253rd National
Meeting & Exposition of the American Chemical Society (ACS). ACS, the
world’s largest scientific society, is holding the meeting here through
Thursday. It features more than 14,000 presentations on a wide range of science
topics.
“Native populations in Canada have long used maple syrup to
fight infections,” says Nathalie Tufenkji, Ph.D. “I’ve always been interested
in the science behind these folk medicines.”
The idea for the project really gelled when Tufenkji, who had
been studying the antimicrobial effects of cranberry extracts, learned of the
anti-cancer properties of a phenolic maple syrup extract.
“That gave me the idea to check its antimicrobial activity,”
Tufenkji says. “So, I sent my postdoc to the store to buy some syrup.”
Using the same extraction approach as other researchers have
in the past, Tufenkji’s team at McGill University separated the sugar and water
from the syrup’s phenolic compounds, which contribute to maple syrup’s
signature golden hue.
In an initial test, the team exposed several disease-causing
bacterial strains to the extract, but they didn’t see much of an effect. Rather
than give up on maple syrup altogether, Tufenkji decided to check whether the
extract could enhance the antimicrobial potency of the commonly used
antibiotics ciprofloxacin and carbenicillin.
When her team mixed the phenolic extract with either of these
medicines, they indeed found a synergistic effect, allowing them to get the
same antimicrobial effect with upwards of 90 percent less antibiotic.
The approach worked on a variety of bacterial strains,
including E. coli, which can cause gastrointestinal problems; Proteus
mirabilis, responsible for many urinary tract
infections; and Pseudomonas aeruginosa, which can cause infections
often acquired by patients in hospitals.
Building on this work, Tufenkji’s team next tested the extract
in fruit flies and moth larvae. The researchers dosed fly food with pathogenic
bacteria and antibiotic, with and without the phenolic extract.
Flies with meals doused in maple syrup extract lived for days
longer than those denied the syrupy topper. The researchers observed a similar
outcome with the moth larvae.
To figure out how the extract makes antibiotics work better,
the researchers investigated whether the extract changed the permeability of
bacterial cells. The extract increased the permeability of the bacteria,
suggesting that it helps antibiotics gain access to the interior of bacterial
cells.
Another experiment suggested that the extract may work by a
second mechanism as well, disabling the bacterial pump that normally removes
antibiotics from these cells.
Currently, the researchers are testing the maple syrup extract
in mice. While it is likely to be years before it would be available to
patients as a prescribed medical protocol, and a pharmaceutical company would
likely need to purify the extract further to avoid any potential allergic
reactions, Tufenkji says, she’s hopeful that it may have an edge over other
would-be medications thanks to its source.
“There are other products out there that boost antibiotic
strength, but this may be the only one that comes from nature,” she says.
Tufenkji acknowledges funding from Canada Research Chairs, the
Natural Sciences and Engineering Research Council of Canada and the William and
Rhea Seath Award at McGill University.
The American Chemical Society is a nonprofit organization
chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world’s
largest scientific society and a global leader in providing access to
chemistry-related research through its multiple databases, peer-reviewed
journals and scientific conferences. ACS does not conduct research, but
publishes and publicizes peer-reviewed scientific studies. Its main offices are
in Washington, D.C., and Columbus, Ohio.
