Maple syrup extract may increase potency of antibiotics

Maple syrup extract may dramatically increase the potency of antibiotics, claim scientists who have found a natural way to prevent the creation of drug-resistant bacteria or "superbugs" by cutting down on dosage of these medicines.

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 niceobes that no longer respond to known antibiotics.

"Native populations in Canada have long used maple syrup to fight infections," said Nathalie Tufenkji from McGill University in Canada.

The idea for the project really gelled when Tufenkji learned of the anti-cancer properties of a phenolic maple syrup extract.

"That gave me the idea to check its antimicrobial activity," Tufenkji said.

Researchers 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 did not 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 per cent 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, researchers 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.