Lindiwe Mpala1, Getmore Chikowe1, Ian Edwin Cock1,2
1School of Environment and Science, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, Brisbane, Queensland, AUSTRALIA.
2Environmental Futures Research Institute, Griffith University, 170 Kessels Rd, Nathan, Brisbane, Queensland, AUSTRALIA.
Published: April 2019
Type: Original Article
Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a genus are known to possess therapeutic properties. The genus Piper has a long history of medicinal usage in many areas of the world. Many Piper spp. are known to have therapeutic properties and several have antibacterial bioactivities. Methods: The ability of P. novae-hollandiae leaf extracts to inhibit the growth of a panel of bacterial pathogens was investigated by disc diffusion assay. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: P. novae-hollandiae methanolic and aqueous extracts were completely ineffective at inhibiting the growth of panels of gram-positive and
gram-negative bacteria. The extracts were nontoxic or of low toxicity to Artemia nauplii following 24 h exposure. Conclusion: Despite the close taxonomic relationship with several bioactive Piper spp. and its therapeutic use by first Australians, P. novae-hollandiae leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is warranted.
Key words: Piperaceae, Giant pepper vine, Australian plant, Traditional medicine, Medicinal plants, Toxicity.