Medieval Potion May Hold Key to Killing Superbug

When you hear stories handed down through generations about what household item kills what bacteria or cures which illness, we often think of it as just an old wives’ tale.  But research is showing that one such potion dating from over 1000 years ago may hold the key to wiping out the superbug MRSA.

The 10th century Anglo-Saxon ‘eye salve’ was found in a leather-bound volume called Bald’s Leechbook and is one of the earliest known medical textbooks, currently held in the British Library.


Christina Lee, an Anglo-Saxon expert from the School of English at the University of Nottingham, translated the ancient manuscript despite a few ambiguities in the text.  The book was selected because it contained recipes using ingredients such as garlic that are currently part of research into potential antibiotic effectiveness.

The recipe was labelled as ‘best of leechdoms’ in the book so the curious researchers wanted to test what it was.  Lee involved microbiologists to see if the remedy could actually work.  It makes use of two types of Allium, garlic and either onion or leek along with wine and oxgall, the bile of a cow’s stomach.  These are brewed together in a brass vessel.

Cooking up

The researchers recreated the recipe as accurately they could as the book gave precise instructions around the ratio of ingredients and for how they should be combined.  Microbiologists Freya Harrison was in charge of the world, from the School of Life Sciences.

The book held instructions for the recipe to be left to stand for nine days before being strained through a cloth.  Part of the efforts for an accurate recreation involved finding wine that was from a vineyard known to have existed in the 9th century, when the book was written, added Steven Diggle, associated professor of sociomicrobiology, another who worked on the project.

Once the recipe was complete, they tested it against cultures of MRSA, or methicillin-resistant Staphylococcus aureus, a type of staph bacteria that normally does not react to any currently used antibiotic treatment.  While they held out little hope of a result, they were surprised by what happened.


The eye salve, it seems, was highly potent as an antibiotic against this particular bacteria in the context it was applied.  The potion took a mature, established population of a few billion cells of the virus that were all clustered together in a protected biofilm coat and reduced them to just a few thousands living cells.  Researchers described this as a ‘massive killing ability’.

The team then passed the recipe to collaborators in the US who tested it ‘in vivo’ or against a living organism and found that it was more effective than any current antibiotic treatment.  They also managed to repeat the test on three more occasions, showing that the first time wasn’t simply a fluke.  The salve also retain potency after being stored for a time in the refrigerator.

The team now has evidence that the medicine can kill up to 90% of MRSA bacteria when tested on wound biopsies from mice.  So while those old wives tales may seem like works of fiction, there may just be some useable facts in there somewhere.

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