March 31, 2009

Tea tree oil, silver kill pathogens

British researchers say tea tree oil is an effective antiseptic, but is even better when mixed with silver.

Both the tea tree oils and the silver -- in the form of silver nitrate -- each effectively fight pathogens involved in skin infections in laboratory tests. However, both became even more effective in lower concentrations -- when combined.

Bacteria such as Staphylococcus aureus, a common cause of skin infections and abscesses and the yeast Candida albicans -- which causes thrush -- were killed.

The researchers at England's University of Wolverhampton also looked at putting tea tree oils or silver nitrate into liposomes. These microscopic spheres are made of phosolipids -- fats -- that occur naturally in cell walls' membranes.

The researchers found the liposomes greatly increased antimicrobial activity. They suggest using liposomes allows controlled release, which lowers the concentrations of the agents needed to treat infected wounds, and could minimize any side effects. Over exposure to silver can result in a bluish-gray skin discoloration and applying unregulated amounts of tea tree oil can cause skin irritation.

The findings were presented at the Society for General Microbiology meeting in Harrogate, England, by researchers Wan Li Low and colleagues.