Cameron Jay Lee1, Mitchell Henry Wright2,*, Anthony Carlson Greene1, Huda Aldosary1, Ian Edwin Cock1,3,*
1School of Environment and Science, Griffith University, Brisbane, Queensland, AUSTRALIA.
2Department of Research and Development, First Choice College, Gold Coast, Queensland, AUSTRALIA.
3Environmental Futures Research Institute, Griffith University, Brisbane, Queensland, AUSTRALIA.
Introduction: Bacillus anthracis is bacterial cause of the highly fatal, zoonotic disease anthrax. Tasmanian pepper (Tasmannia lanceolata) has been previously documented for its antiseptic properties against other pathogenic bacteria. This study sought to investigate the effectiveness of T. lanceolata as an inhibitory agent against B. anthracis. Methods: Tasmannia lanceolata berry and leaf extracts were prepared with either water or methanol as the extraction solvent. Growth inhibition was assessed against B. anthracis strain PMO through disc diffusion as assaying. The relative MIC values of each extract was quantified to evaluate efficacy as a sterilant. The degree of toxicity of each extract was achieved using the widely used Artemia franciscana nauplii bioassay. Results: T. lanceolata leaf extracts inhibited the growth of B. anthracis in the disc diffusion assay, with MIC values of 2333 and 1873 μg/mL respectively. In contrast, the T. lanceolata berry extracts were completely devoid of growth inhibitory activity. All T. lanceolata extracts (both berry and leaf) were non-toxic (LC50 values substantially >1000 μg/mL) as determined via the Artemia franciscana bioassay. Conclusion: T. lanceolata berry and leaf extracts are not only non-toxicity, but also had moderate growth inhibitory bioactivity against B. anthracis, highlighting their potential in the treatment of anthrax.