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Medieval Salve Could Fight Modern Germs

The British Library Board (Royal 12 D xvii)

You might not have known that the world has an Ancientbiotics research team, but it does, and it has just figured out that a compound from medieval days called “Balds eyesalve” is pretty effective at blasting tough bacteria. It doesn’t have eye of newt, but it does contain cow bile.

Checking the Leechbook

The Ancientbiotics team was formed in 2015 with members from England and the United States, including microbiologists, philologists (people who study the history of languages), historians, and chemists. One member of the team, Christina Lee, from the School of English at the University of Nottingham, found the recipe for Balds eyesalve while examining Bald’s Leechbook, a collection of remedies from around 900 AD. While many of the “cures” in the book seem outlandish today, such as salves against elves, goblins, and devils, the team proved that the eyesalve was effective in killing 90% of MRSA bacteria in 2015, so they set out to try it on other bacteria.

Sure enough, the potion—which consists of garlic, wine and bile salts (a liver secretion stored in the gallbladder and taken from cows in this case)—worked again. 

Biofilm Blaster

This time, the team was curious to know if the remedy would be effective against antibiotic-resistant bacteria, which exist in two forms: alone as “planktonic” cells, or together in the much harder to defeat form known as biofilms. If you’ve ever tried to scrub out the scum left behind in an old vase of flowers, you’re familiar with biofilms, which are basically bacteria which group in colonies to strengthen themselves and avoid death. 

Biofilms are notoriously hard to kill with standard antibiotics, particularly in diabetic foot ulcers. 

In cultures, the team found that Balds eyesalve was effectively able to kill five different strains of bacteria, both as single cells and biofilms, all of which can infect diabetic ulcers that can lead to amputations if not treated effectively.

Stronger Together

The team emphasized the importance of the combination of ingredients as, although it’s already known that the allicin in garlic is effective against planktonic bacterial cultures, it has not worked against biofilms.

“Most antibiotics that we use today are derived from natural compounds, but our work highlights the need to explore not only single compounds but mixtures of natural products for treating biofilm infections,” said Freya Harrison, from the School of Life Sciences at the University of Warwick. “We think that future discovery of antibiotics from natural products could be enhanced by studying combinations of ingredients, rather than single plants or compounds. In this first instance, we think this combination could suggest new treatments for infected wounds, such as diabetic foot and leg ulcers.” 

The findings have been published in the journal Nature.