Scientists are hopeful that a stomach-churning Medieval sty treatment of blended cow’s bile, garlic, and onions could be an effective treatment against some antibiotic-resistant bacterial infections. Known as Bald’s eyesalve, the unusual therapy showed promising antibacterial activity against problematic strains of Staphylococcus and Streptococcus.
The study, published in the journal Scientific Reports, recreated the 1,000-year-old medieval remedy containing onion, garlic, wine, and bile salts. They wanted to assess its efficacy against bacterial infections that are difficult to treat because the microbes form a biofilm protecting them against antibiotics. This sort of infection is often the cause of worsening diabetic foot ulcers, which can be extremely difficult to treat and lead to amputation.
The researchers at the University of Warwick, UK, grew Gram-negative and Gram-positive wound pathogens in a planktonic culture and found that the modernized Bald’s eyesalve was effective against a range of pathogens. It was even able to combat bacteria that formed biofilms including Staphylococcus aureus – which causes skin abscesses, respiratory infections, and food poisoning – and Streptococcus pyogenes, which causes tonsillitis, scarlet fever, cellulitis, and rheumatic fever.
The research builds on a body of Ancientbiotics work that has been carrying out experiments since 2015. Armed with an interdisciplinary group of researchers including microbiologists, chemists, pharmacists, data analysts, and medievalists at Warwick, Nottingham, and in the United States, the work hopes to fill the gaps in antibiotic resistance with old solutions.
It might sound like lunacy, but there’s method in the madness for a therapy like Bald’s eyesalve. Garlic contains allicin, which could account for the treatment’s efficacy against planktonic cultures. However, garlic alone has no impact on biofilms so it seems the specific combination of all the wacky ingredients in Bald’s eyesalve is what makes this unusual treatment effective against such challenging infections.
"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 Dr Freya Harrison, from the School of Life Sciences at the University of Warwick, in a statement. “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."
Antibiotic resistance is a cause for increasing concern among scientists, as more antimicrobials are urgently needed to treat biofilm-associated infections. The Ancientbiotics team remains optimistic that lessons can be learned from medieval methods, which used natural antimicrobials from everyday ingredients to find new answers.