The safety of a medieval remedy for the treatment of diabetic foot infections

The rise in antimicrobial resistance has prompted the use of alternatives such as plant derived compounds. Previous research from the lab showed that an ancient remedy, Bald‘s eyesalve used in the Anglo-Saxon period had efficacy against Staphylococcus aureus grown in an in vitro model of soft tissue infections (Harrison et al., 2015). Furthermore, this remedy also had efficacy against methicillin-resistant S. aureus (MRSA) in an in vivo mouse model (Harrison et al., 2015). The current research focussed on determining the safety of the ancient remedy in vitro, ex vivo, and in vivo. To do this, the ancient remedy was prepared, mixed together and kept in the fridge for 9 days as specified in the recipe. First, it was tested against a range of Gram-negative and positive wound pathogens in planktonic cultures and biofilms. Next, the safety of the remedy was determined using a range of models: cell lines, bovine corneal opacity permeability test, slug mucosal irritation assay and mice models. Low levels of cytotoxicity was observed in eyesalve treated cell lines representative of skin and immune cells. The results from the BCOP test demonstrated slight irritation to the cornea that resolved within 15 mins and the level of mucus secreted in the slugs were similar to that in the saline control indicating no mucosal irritation. Furthermore, we obtained promising results from the mice wound closure experiments as no visible signs of irritation or inflammation was observed. This research has the potential to transform the management of diabetic foot infections.