The Leech Book. Credit: © The British Library Board (Royal 12 D xvii)
- To combat antibiotic resistance, more antimicrobials are needed to treat bacterial biofilms, which protect an infection from antibiotics.
- Using the medieval ‘Balds eyesalve’ mixture that contains natural ingredients such as garlic every day, researchers from the Warwick university discovered that it was effective against five bacteria that cause modern biofilm infections
- This shows that the future discovery of antibiotics from natural products could be improved by studying combinations of ingredients.
Antibiotic resistance is an increasingly difficult battle for scientists to overcome as more antimicrobials are urgently needed to treat biofilm-associated infections. However, scientists at the University of Warwick School of Life Sciences say research on natural antimicrobials could provide candidates to fill the antibiotic discovery gap.
The Baldes Eyesalve mix in the laboratory. Credit: University of Warwick
Bacteria can live in two ways, as individual planktonic cells or as a multicellular biofilm. The biofilm helps protect bacteria from antibiotics, making them much more difficult to treat, one of those biofilms that is particularly difficult to treat is the one that infects diabetic foot ulcers.
Researchers from the University of Warwick, Dr. Freya Harrison, Jessica Furner-Pardoe and Dr. Blessing Anonye, have discussed natural remedies for the gap in the antibiotic market, and in the document, ‘Anti-biofilm efficacy of a medieval treatment for bacterial infection requires the combination of multiple ingredients’ published in the magazine Scientific reports Today (July 28, 2020), researchers say medieval methods using natural antimicrobials from everyday ingredients could help find new answers.
The Ancientbiotics Research Team was established in 2015 and is an interdisciplinary group of researchers that includes microbiologists, chemists, pharmacists, data analysts, and medievalists in Warwick, Nottingham, and the United States.
The actual text of the eye drops remedy. Credit: © The British Library Board (Royal 12 D xvii)
Building on previous research by the University of Nottingham on the use of medieval remedies to treat MRSA, researchers at the University of Warwick School of Life Sciences reconstructed a 1000-year-old medieval remedy containing onion, garlic , wine and bile salts, which is known as “Bald’s eye drops” and was shown to have promising antibacterial activity. The team also demonstrated that the mixture caused low levels of damage to human cells.
They found that the remedy for Bald’s eye drops was effective against a variety of Gram-negative and Gram-positive wound pathogens in plankton culture. This activity is maintained against the following pathogens grown as biofilms:
- Acinetobacter baumanii commonly associated with Infected wounds in combat troops returning from conflict zones.
- Malophyll Stenotropomone- commonly associated with respiratory infections in humans
- Staphylococcus aureus a common cause of skin infections, including abscesses, respiratory infections such as sinusitis, and food poisoning.
- Staphylococcus epidermidis- A common cause of infections involving permanent foreign devices such as a catheter, surgical wound infections, and bacteremia in immunocompromised patients.
- Streptococcus pyogenes – It causes numerous infections in humans, including pharyngitis, tonsillitis, scarlet fever, cellulitis, rheumatic fever and post-streptococcal glomerulonephritis.
All of these bacteria can be found in biofilms that infect diabetic foot ulcers and may be resistant to antibiotic treatment. These debilitating infections can lead to amputation to avoid the risk of bacteria spreading into the blood and causing lethal bacteremia.
The use of garlic in Bald’s eye drops mixtures, which contains allicin, may explain the activity against planktonic cultures, however, garlic alone has no activity against biofilms and, therefore, the anti-biofilm activity of eye drops. Bald’s cannot be attributed to a single ingredient and requires the combination of all ingredients to achieve full activity.
Dr. Christina Lee with the Leechbook. Credit: University of Nottingham.
Dr. Freya Harrison of the University of Warwick School of Life Sciences comments: “We have shown that a medieval remedy made from onion, garlic, wine and bile can kill a variety of problem bacteria grown on both plankton and in biofilms. Because the mixture did not cause much harm to human cells in the laboratory, or to mice, we could develop a safe and effective antibacterial treatment from the remedy.
“Most of the antibiotics we use today are derived from natural compounds, but our work highlights the need to explore not only single compounds but also mixtures of natural products to treat biofilm infections. We believe that the future discovery of antibiotics from natural products could be improved by studying combinations of ingredients, rather than individual plants or compounds. In this first instance, we believe that this combination could suggest new treatments for infected wounds, such as diabetic foot and leg ulcers. “
Jessica Furner-Pardoe of the University of Warwick School of Medicine comments: “Our work demonstrates how important it is to use realistic models in the laboratory when looking for new plant antibiotics. Although a single component is sufficient to kill plankton crops, it fails against more realistic infection models, where the complete remedy is successful. ”
The Leech Book. Credit: © The British Library Board (Royal 12 D xvii)
In previous research, Christina Lee of the University of Nottingham’s School of English had examined Bald’s Leechbook, an old English volume in the British Library, to see if it really works as an antibacterial remedy. The Leechbook is widely regarded as one of the earliest known medical textbooks and contains Anglo-Saxon advice and prescriptions for medications, ointments, and treatments.
Christina adds: “Bald’s eye drops underscore the importance of medical treatment throughout the centuries. It shows that people in early medieval England had at least some effective remedies. The collaboration that has informed this project shows the importance of the arts in interdisciplinary research. “
Reference: “The anti-biofilm efficacy of a medieval treatment for bacterial infection requires the combination of multiple ingredients” by Jessica Furner-Pardoe, Blessing O. Anonye, Ricky Cain, John Moat, Catherine A. Ortori, Christina Lee, David A. Barrett Christophe Corre and Freya Harrison, July 28, 2020, Scientific reports.
DOI: 10.1038 / s41598-020-69273-8
