Medieval Anglo-Saxon medics were definitely up to something as a new research that brewed a potion using 100-year-old remedy involving two species of Allium (garlic and onion or leek), wine and oxgall (bile from a cow’s stomach) managed to kill the modern-day superbug MRSA.
The potion is actually listed as one that treats eye infections in Bald’s Leechbook – an Old English leatherbound volume in the British Library believed to be one of the earliest known medical textbooks containing Anglo-Saxon medical advice and recipes for medicines, salves and treatments.
Early results on the ‘potion’, tested in vitro at Nottingham and backed up by mouse model tests at a university in the United States, are, in the words of the US collaborator, “astonishing”.
The solution has had remarkable effects on Methicillin-resistant Staphylococcus aureus (MRSA) which is one of the most antibiotic-resistant bugs costing modern health services billions.
So where did the idea of brewing a 1000-year-old potion come from? It was the idea of Dr Christina Lee, an Associate Professor in Viking Studies and member of the University’s Institute for Medieval Research at the University of Nottingham. Dr Lee translated the recipe from a transcript of the original Old English manuscript in the British Library.
The recipe calls for two species of Allium (garlic and onion or leek), wine and oxgall (bile from a cow’s stomach). It describes a very specific method of making the topical solution including the use of a brass vessel to brew it in, a straining to purify it and an instruction to leave the mixture for nine days before use.
The scientists at Nottingham made four separate batches of the remedy using fresh ingredients each time, as well as a control treatment using the same quantity of distilled water and brass sheet to mimic the brewing container but without the vegetable compounds.
The remedy was tested on cultures of the commonly found and hard to treat bacteria, Staphylococcus aureus, in both synthetic wounds and in infected wounds in mice.
The team made artificial wound infections by growing bacteria in plugs of collagen and then exposed them to each of the individual ingredients, or the full recipe. None of the individual ingredients alone had any measurable effect, but when combined according to the recipe the Staphylococcus populations were almost totally obliterated: about one bacterial cell in a thousand survived.
The team then went on to see what happened if they diluted the eye salve – as it is hard to know just how much of the medicine bacteria would be exposed to when applied to a real infection. They found that when the medicine is too dilute to kill Staphylococcus aureus, it interfered with bacterial cell-cell communication (quorum sensing).
This is a key finding, because bacteria have to talk to each other to switch on the genes that allow them to damage infected tissues. Many microbiologists think that blocking this behaviour could be an alternative way of treating infection.
The team now has good, replicated data showing that Bald’s eye salve kills up to 90% of MRSA bacteria in ‘in vivo’ wound biopsies from mouse models. They believe the bactericidal effect of the recipe is not due to a single ingredient but the combination used and brewing methods/container material used. Further research is planned to investigate how and why this works.
