Researchers from the University of Texas and Shriners Hospitals for Children say a compound from licorice root (glycyrrhizin from Glycyrrhiza glabra) might be an effective treatment for antibiotic-resistant infections resulting from severe burns. Their new study featured in the Journal of Leukocyte Biology suggests that glycyrrhizin may improve the ability of damaged skin to create antimicrobial peptides, proteins that serve as the first line of defense against infection.

To make the discovery, the researchers used three groups of mice. The first group was normal, the second group was burned and untreated, and the third group was burned and treated with
glycyrrhizin. The skin of the untreated burned mice did not have any detectable antimicrobial peptides that prevent bacteria from growing and spreading, but the normal mice did. The skin of the untreated burned mice also had immature myeloid cells, which indicate an inability of the skin to produce antimicrobial peptides needed to prevent infection. The mice treated with glycyrrhizin, however, were more like the normal mice as they had the antimicrobial peptides and no immature myeloid cells.

"It is our hope that the medicinal uses of glycyrrhizin will lead to lower death rates associated with infection in burn patients," said Fujio Suzuki, Ph.D., one of the researchers involved in the work. Suzuki also said that more research is necessary to determine if this finding would have any implications for people with cystic fibrosis, who can develop Pseudomonas aeruginosa infections in their lungs.

"Burns are the most painful of all injuries," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, "and the deadly Pseudomonas infections that can result from severe burns do more than add insult to those injuries. This research should serve as an important stepping stone toward helping develop new drugs that help prevent or treat Pseudomonas."






Citation: Tsuyoshi Yoshida, Shohei Yoshida, Makiko Kobayashi, David N. Herndon, Fujio Suzuki, 'Pivotal Advance: Glycyrrhizin restores the impaired production of β-defensins in tissues surrounding the burn area and improves the resistance of burn mice to Pseudomonas aeruginosa wound infection', Journal of Leukocyte Biology, 2010, 87:35-41; doi: 10.1189/jlb.1208760