Submitted to: Cryptogamie Bryologique
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/10/2007
Publication Date: 10/15/2007
Citation: Millar, K.D.L., Crandall-Stotler, B., Ferreira, J.F.S., Wood, K.V. 2007. Antimicrobial properties of three liverworts in axenic culture: Blasia pusilla, Pallavicinia lyellii and Radula obconica. Cryptogamie Bryologique. 28(3):197-210. Interpretive Summary: Drug resistant microorganisms often are cited as a cause of health complications and death among humans and animals. A diverse arsenal of drugs with modes of action that differ from those currently in use are needed. More evolved (higher) plants are the source of many compounds used to fight drug-resistant microorganisms. However, a group of primitive, small, mat-like plants, called liverworts or hepatics show promise of providing some anti-microbial compounds not usually found in higher plants. We evaluated three species of liverworts grown under laboratory conditions, and isolated compounds from one of the three species which inhibited the growth of disease causing or pathogenic bacteria. The compounds potentially can have antimicrobial effects against other disease causing organisms. These findings call the attention to the vast potential for primitive plants as a source of antibacterial compounds.
Technical Abstract: Many liverworts can deter the growth of pathogenic agents such as fungi and bacteria. It has been generally assumed that the chemicals liverworts produce in their oil bodies are responsible for this activity. However, few studies have isolated and identified the specific compounds that are biologically active. This study aims to expand existing knowledge of biological activity of liverworts by isolating and identifying the compounds that are responsible for their observed activity. To this end, Blasia pusilla L., Pallavicinia lyellii (Hook.) Carruth. and Radula obconica Sull. were tested for antimicrobial activity against Bacillus subtilis, Escherichia coli, and Aspergillus niger. Only R. obconica displayed antibacterial activity, and this activity was only against B. subtilis. These findings suggest its potential as a source of bioactive compounds against other Gram positive bacteria. Several fractions of the extract obtained from R. obconica displayed antibacterial activity. The most active compounds in these fractions are bibenzyls, compounds that are widespread in liverworts but of only sporadic occurrence in other plants.