Evaluation of the Anti-Yersinia Activity of Botanicals Used During the Black Plague

Evaluation of the Anti- Yersinia Activity of Botanicals Used During the Abstract Background: During the fourteenth century, the Black Plague ravaged through Europe. At this time, records described using specific botanical formulations, the “Four Thieves” recipe and Nostradamus’ “Rose Petal Lozenges”, as successful therapies for preventing plague-associated bacterial infections. Purpose: This study describes the characterization of the antibacterial activity associated with botanical extractions prepared from these medieval formulations against Yersinia pseudotuberculosis , a related species of Y. pestis , the causative agent of the Plague. Methods: Ethanol and acetic acid extracts were prepared from16 botanicals that may have been used in masks or formulated into tinctures to protect medieval populations from contracting the Plague. These extracts were tested in a dose-dependent manner related to inhibition of the growth of Y. pseudotuberculosis . Results and Conclusions: The results suggest which botanicals may have been useful in reducing infection during the historically detrimental pandemic of Y. pestis . With a renewed and emerging threat of Yersinia -related infections, the results provide insight into the history of botanical medicine and indicate which botanicals may act as another defensive measure against future Yersinia -related infections.