Chinese herb explained

American scientists could have discovered why the ancient Chinese compound rubricine is effective in burn treatment, and the findings also suggest that microbes may be slow to develop resistance to the herb.

A team of Maryland researchers may be able to explain the beneficial effects of rubricine, a herb widely used in traditional Chinese medicine, according to a report from Reuters Health.

The bright red coloured herb is extracted from the roots of the Arbenia euchroma plant, and has been used in Asia both as a dye and also to help heal wounds and treat burns.

At last week's American Society for Microbiology's annual meeting, scientist Chi S. Chae explained that the extract contains six closely related compounds and appears to have antibacterial properties.

In an interview with Reuters Health, Chae said that the compounds fight bacteria in two ways - they both destroy them and also prevent bacterial growth. Most antibiotics have only one of these properties, she said and the rubricine has also been linked to the destruction of fungi.

Tests showed rubricine was also effective against bacteria that were resistant to several antibiotics, notes the report.

In order to explain how the compound worked, Chae used mutant bacteria that would be resistant to it, but these mutants took a long time to develop and showed only partial resistance to rubricine.

She noted that this suggests that rubricine fights bacteria by a unique method, and that bacteria will not readily develop resistance to it. The next step is to find out how rubricine fights bacteria, using genetic analysis of the mutants and other techniques.

The rubricine compounds were also found to be non-mutagenic (the ability of a substance to cause genetic mutations in living things) and non-toxic. In some cases they were able to bar the action of other compounds that are mutagenic.