A medieval concoction meant to treat eye infections has surprised researchers in Britain and the US as it's also capable of killing the MRSA superbug.

The recipe comes from the 10th century and calls for two species of Allium (garlic and onion or leek), wine and bile from a cow's stomach. A brass vessel was used to brew the topical potion. It was then strained and left to sit for nine days.

The ingredients used are known to have antibacterial properties. "We thought that Bald's eyesalve might show a small amount of antibiotic activity, because each of the ingredients has been shown by other researchers to have some effect on bacteria in the lab", said microbiologist Freya Harrison.

Bacteria could not survive copper and bile salts, and the garlic family of plants is well capable of making chemicals that alter the bacteria's ability to cause damage to infected tissues.

After performing their tests, the researchers were left surprised noting the fact that the combination of ingredients was very effective.

They made use of fresh ingredients as per the original instructions and potion exposure was given to population of Staphylococcus aureaus, the antibiotic-resistant bacteria MRSA, both in lab cultures and on infected wounds in mice.

Dr. Christina Lee, professor at the School of English at Nottingham University, said they were left flabbergasted by the results of their experiments in the lab. The study has made it quite clear that past responses and knowledge could provide significant help in modern research. The remedies similar to this one were developed even before germ theory was understood.

Steve Diggle of the microbiology lab said it was really amazing to know that the recipe is so effective at killing cells in S. aureus biofilms. It was a great result as biofilms are naturally antibiotic resistant and difficult to treat.