Inappropriate and overuse of antibiotics has led to the emergence of drug-resistant strains and superbugs – a major public health problem that is in urgent need of solutions. Now, a team of researchers at McGill University in Montreal, Canada, suggest that one solution may lie in the sap of Maple trees.
Phenolic compounds play an important role in the growth and development of plants by helping them defend against pathogens. Maple syrup contains phenolic compounds, which are of interest due to their antiseptic and antioxidant properties.
For the study, Prof. Tufenkji, a chemical engineering professor and colleagues bought maple syrup at local markets and kept it in the freezer until the start of each experiment. They put each sample through a series of steps to produce the phenolic-rich extract. The extract was tested on a number of infection-causing bacteria such as Escherichia coli and Proteus mirabilis – a common cause of urinary tract infection.
The maple syrup extract on its own was mildly effective against the infection-causing bacteria. But it was even more effective against bacteria when combined with antibiotics. They found that the maple syrup extract and antibiotic combination was particularly effective at destroying biofilms – resistant communities that inhabit surfaces and are particularly hard to shift with antibiotics.
Maple syrup extract affect the bacteria in a number of ways to make them more susceptible to antibiotics. One effect is that the extract makes cell membranes of bacteria more porous, thus making it easier for the antibiotics to enter the microbial cells. The maple syrup extract also shuts down the “efflux pumps” that the bacteria use to push any antibiotic that makes it through the membrane out of the cell. And a third way that the extract weakens the bacteria is by reducing expression of genes linked to antibiotic resistance and virulence.
One potential benefit would be to reduce the use of antibiotics and thus slow the rate at which resistant strains emerge. Although, more extensive work needs to be done, and clinical trials conducted, before the effect on humans is predicted, the researchers say the study is a first step that proves the concept.
Prof.Tufenkji says that the findings suggest a potentially simple and effective approach for reducing antibiotic usage. He believes that eventually the maple syrup extract will be incorporated into the capsules of antibiotics.
