How A 10th Century Garlic Salve Killed Drug Resistant MRSA
Bald's Eyebalm Blasts Methicillin-Resistant Staphylococcus aureus (MRSA)
When Christina Lee, from the University of Nottingham, found an old eye infection remedy called Bald's eyesalve in a 10th Century medical volume she was intrigued. The medical book, Bald's Leechbook, is one of the earliest known medical textbooks and is written in Old English. Some forms of eyelash infection are caused by Staphylococcus aureus which is related to the bacteria involved with drug resistant MRSA.
Bald's eyesalve combined equal parts of garlic, cropleac, wine and bile from a cow's stomach. The alliums were ground and all ingredients placed in a brass container for nine days before being clarified through a cloth.
Lee decided it would be fun to see if the ancient prescription really worked on bacterial infections. She took it to her colleague, microbiologist Freya Harrison, to test out. They decided to look at different preparations to see if the mixture was more effective when made as directed or if one ingredient was responsible for the antimicrobial effects.
They found that Bald's eyesalve was most effective when the recipe was followed closely. It killed up to 90% of MRSA bacteria. All the ingredients were essential except the brass container.
Here is the recipe (translated by the BBC and modified slightly by me to make the directions clearer):
- Use equal amounts of garlic and another allium (either onion or leek), finely chopped and crushed in a mortar for two minutes. The researchers used 25 ml garlic and 25 ml of either yellow onion or leek leaves.
- Add 25ml (0.87 fl oz) of English wine (the researchers used wine from a historic vineyard near Glastonbury, England).
- Dissolve 25 ml bovine salts (also called bile salts) in distilled water. Researchers dissolved bovine bile salts in water at a concentration of 87 mg·ml−1. They poured the garlic, onion or leek, wine and diluted bile salt into a 250 ml bottle.
- Keep mixture chilled for nine days at 4 degrees Celsius before straining through a cloth to remove particulates (large pieces). Use.
The researchers in this experiment substituted either leeks or onions for cropleac (which is an allium but what allium it is, is anyone's guess). Making up a fresh batch of medieval eyebalm as the instructions directed, Harrison and her team tested it on antibiotic-resistant bacteria, methicillin-resistant S. aureus (MRSA), in lab cultures and on mice with MRSA infected wounds. Bald's eyesalve devastated MRSA, killing 999 out of 1,000 bacterial cells. It repetitively killed established S. aureus biofilms in an in vitro model of soft tissue infection and killed MRSA in a mouse chronic wound model.
This is not a surprise. Previous research has shown that garlic compounds are extremely effective against MRSA in the lab and in mice with MRSA (Tsao et al. 2003, Cutler and Wilson 2004, Tsao et al. 2007). Garlic's sulfur compounds are able to etch through bacterial biofilms. These biofilms can be a significant barrier to conventional antibiotics.
Why MRSA is a Problem
MRSA infections are on the rise and many are not reported. Deaths from this infection are under reported since frequently physicians will not state MRSA infection as the cause of death. Rather they will state that the patient died of "complications resulting from ...whatever the primary reason they were in the hospital when they caught MRSA". Kaye et al. (2008) reported that 1/3 of patients with bloodstream MRSA infection died in community hospitals.
MRSA started due to the overuse of antibiotics in hospitals. Staph (Staphylococcus aureus) bacteria mutated to become resistant to common antibiotics.
According to the Center for Disease Dynamics, Economics and policy (CDDEP) the USA
Cropleac is the the Old English name for an allium species. It may be a species of chive, garlic, shallot, onion or leek; there is some debate about the exact species. The second part of the word 'leac' means leek which was commonly used to refer to the allium family. The prefix was used to distinguish between the various types of alliums such as garlic, leeks, onions, chives and so on. In this case, the prefix may refer to the shape of the leaves. For example, garlic was known as garleac or spear leek due to its tapered leaves resembling a spear. Similarly cropleac mean sprout leek. Due to this definition, some people think that cropleac may refer to a chive species.
by Susan Fluegel, PHD
References
- Cutler RR, Wilson P. Antibacterial activity of a new, stable, aqueous extract of allicin against methicillin-resistant Staphylococcus aureus. Br J Biomed Sci. 2004; 61:71-4. Pubmed. Full text.
- Harrison F, Roberts AEL, Gabrilska R, Rumbaugh KP, Lee C, Diggle SP. A 1,000-year-old antimicrobial remedy with antistaphylococcal activity. mBio. 2015; 11;6(4):e01129. Pubmed. Full text. doi: 10.1128/mBio.01129-15.
- Kaye KS, Anderson DJ, Choi Y, Link K, Thacker P, Sexton DJ. The deadly toll of invasive methicillin-resistant Staphylococcus aureus infection in community hospitals. Clin Infect Dis. 2008;46:1568–77. PubMed. Full text. doi: 10.1086/587673.
- Tsao SM, Hsu CC, Yin MC. Garlic extract and two diallyl sulphides inhibit methicillin-resistant Staphylococcus aureus infection in BALB/cA mice. J Antimicrob Chemother. 2003;52(6):974-80. Pubmed. Full text.
- Tsao SM, Liu WH, Yin MC. Two diallyl sulphides derived from garlic inhibit meticillin-resistant Staphylococcus aureus infection in diabetic mice. J Med Microbiol. 2007;56:803-8. Pubmed. Full text.