When the story came across my desk, it sounded too sweet to be true: our iconic Canadian elixir can actually help antibiotics vanquish resistant bacteria. Researchers at McGill University in Montreal have found that some of the chemicals in maple syrup — a phenolic fraction — can help antibiotics in two ways: by breaking down biofilms that many bacteria build to protect themselves and by stopping the action of “pumps” inside bacteria that flush antibiotics out of the bacteria. The maple syrup extract also affects the genes that make bacteria infective.
But this type of ability is not that unusual in plants. I have had the pleasure of working with a researcher in Mexico, Dr. Francisco Espinosa García, as well as students in his lab, who study “chemical ecology” – the chemicals produced by plants and animals that affect their interactions. For example, one of his students had an interesting paper on how tomatoes adapt genetically to produce a chemical that repels the tomato’s most common pest. Plants have complex chemical “immune systems” that fight off pests and infections. It is no wonder that these chemicals are often antibacterial.
Back 10 years ago, the Canadian Journal of Microbiology published a very interesting article from researchers in Brazil, where a methanolic pomegranate extract has been used as a folk remedy for infections. The researchers found that the extract worked synergistically with various antibiotics against many strains of methicillin-resistant Staphylococcus aureus (MRSA), one of the most feared infections today. There were some problems with the research – the antibiotics tested were older drugs no longer available in many industrialized countries and the tests were in a lab, not in people – but the principle was there.
As I mentioned in my previous post, the answer to antibiotic resistance may not involve going to the ends of the earth, but looking at the natural processes all around us to discover ways to combat pathogens with pomegranates, tomatoes and maple syrup.
When I was hired at the Canadian Medical Association Journal in 1991, it was because there were so many ads for drugs that they needed people to edit copy to keep the ads from bumping into each other. I joked that Prozac was paying my salary.
It turns out that was the crest of a wave of innovative drug discovery. Releases of novel drugs are less common today. Many of the new drugs are “biologics” engineered from DNA or proteins, many of which are for chronic conditions and diseases. And a lot of new drugs are so-called “me too” drugs, similar to other recently released drugs so that the manufacturer can grab some of the market. In this picture, there has been little new for pathogenic illnesses since the protease inhibitors revolutionized HIV treatment. It’s as if everyone has figured all the antibiotics have been found.
I recently covered the discovery of a new antibiotic for CMAJ. Several other media outlets had the story as well — it had been published in Nature. But I quickly realized that the particular antibiotic wasn’t the story. There had been some excellent features recently on “antibiotic hunters” who were scuba-diving in Greenland to find new antibiotics. Literally going to the ends of the earth. The reason for the extreme measures is that sources of antibiotics nearer to the lab had been “overmined” in the words of several researchers. The real story is that several research teams have figured out new ways to find antibiotics from old sources. There are lots of antibiotics all around us: we just didn’t know how to “tame” them, as the researchers call it. Some of the newly discovered antibiotics are coming from people’s back yards!
A lot has been made of the use of these novel antibiotics to overcome resistance, as this is a major problem in infection control. Bacteria and viruses adapt genetically very quickly, doing a kind of DNA juggling that other organisms can’t even do, swapping genes with other bacteria and reorganizing their own DNA. How can lengthy drug development cycles keep up with these fleet pathogens?
Yes, resisting resistance is one benefit of novel antibiotics. However, I think the molecules and pathways now being studied will go much farther than addressing resistance. If researchers can find thousands of potential antibiotics, some of them may be active against viruses — for which we still have very little –, cancer, and many chronic diseases for which we do not know the cause but which may be pathogenic. In fact, in a generation or two we may think of drugs in an entirely new way, as capable of curing illnesses minor and grave that today are accepted as incurable. A century from now, medicine may be as far ahead from today as it is today from our grandparents’ day.