Extracts of Lomandra hystrix Labill. Aerial Parts Lack Antibacterial Activity and are Non-toxic in vitro

Introduction: The development of bacterial strains that are resistant to multiple antibiotics has made the discovery of new antibiotics a priority for medical research. Examination of plants for new antimicrobial agents is an attractive prospect and numerous recent studies have screened plants for antibacterial activity. Despite this, many plant species are yet to be tested for antibacterial activity. Lomandra hystrix Labill. is a perennial rhizomatus herb of the family Asparagaceae that grows widely throughout eastern Australia The antibacterial properties of this plant are yet to be studied against human pathogens. Methods: The ability of extracts prepared from L. hystrix aerial parts 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: L. hystrix methanolic and aqueous extracts were ineffective at inhibiting the growth of panels of gram-positive and gram-negative bacteria. The extracts were non-toxic or of low toxicity in the Artemia nauplii bioassay following 24 hr exposure. Conclusion: The L. hystrix extracts lacked growth inhibitory bioactivity against a panel of pathogenic bacteria and were non-toxic in the Artemia nauplii assay. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is required.