Avoiding pitfalls in determining antimicrobial activity of plant extracts and publishing the results

There is an urgent need to discover new antimicrobial compounds or extracts to address the crucial problem of increasing microbial resistance against current antibiotics. Plant chemical biodiversity is a valuable potential resource. Although compounds from plants are used as basis for several human drugs, no commercially successful antibiotic has yet been discovered from plants, despite more than a thousand publications in this field per year. This may be due to wrong methods that have been used or wrong plants that were investigated. A lot of energy is wasted by using techniques such as agar diffusion that do not work well with plant extracts. Many manuscripts are rejected before sending to reviewers because wrong methods are used. Antimicrobial activity of plant extracts based on agar diffusion studies have limited value.

Results obtained from several hundred of our publications in this area as researcher and experience as editor was used to identify difficulties in generating reproducible data. Other publications were also consulted and procedures used were evaluated.

By using proposed methods manuscripts will provide reproducible information that may be published in good journals. The publications could contribute to a rational basis for finding compounds or extracts from plants that may address the problem of antimicrobial resistance. Random screening of a large number of plant species using this technique have already led to some commercial applications and identification of a potentially new antifungal framework compound.