Mānuka oil is an essential oil derived from Leptospermum scoparium, a plant that has been used by the indigenous populations of New Zealand and Australia for centuries. Both the extracted oil and its individual components have been associated with various medicinal properties. Given the rise in resistance to conventional antibiotics, natural products have been targeted for the development of antimicrobials with novel mechanism of action. This review aimed to collate available evidence on the antimicrobial, anti-parasitic and anti-inflammatory activities of mānuka oil and its components. A comprehensive literature search of was conducted using PubMed and Embase (via Scopus) targeting articles from database inception until June 2020. Chemical structures and IUPAC names were sourced from PubChem. Unpublished information from grey literature databases, Google search, targeted websites and Google Patents were also included. The present review found extensive in vitro data supporting the antimicrobial effects of mānuka oil warrants further clinical studies to establish its therapeutic potential. Clinical evidence on its efficacy, safety and dosing guidelines are necessary for its implementation for medical purposes. Further work on regulation, standardization and characterization of the medicinal properties of mānuka oil is required for establishing consistent efficacy of the product.
Keywords: Leptospermum scoparium; antibacterial; antimicrobial; antiparasitic; medicinal; mānuka oil; therapeutic properties.