Phytochemical Profile and Antibacterial and Antioxidant Activities of Medicinal Plants Used by Aboriginal People of New South Wales, Australia

Abstract

Aboriginal people of Australia possess a rich knowledge on the use of medicinal plants for the treatment of sores, wounds, and skin infections, ailments which impose a high global disease burden and require effective treatments. The antibacterial and antioxidant activities and phytochemical contents of extracts, obtained from eight medicinal plants used by Aboriginal people of New South Wales, Australia, for the treatment of skin related ailments, were assessed to add value to and provide an evidence-base for their traditional uses. Extracts ofAcacia implexa,Acacia falcata,Cassytha glabella,Eucalyptus haemastoma,Smilax glyciphylla,Sterculia quadrifida, andSyncarpia glomuliferawere evaluated. All extracts except that ofS. quadrifidashowed activity against sensitive and multidrug resistant strains ofStaphylococcus aureuswith minimum inhibitory concentration values ranging from 7.81 to 1000 μg/mL. The sap ofE. haemastomaand bark ofA. implexapossessed high total phenolic contents (TPC) and strong DPPH radical scavenging abilities. A positive correlation was observed between TPC and free radical scavenging ability. GC-MS analysis of then-hexane extract ofS. glomuliferaidentified known antimicrobial compounds. Together, these results support the traditional uses of the examined plants for the treatment of skin related ailments and infections by Aboriginal people of New South Wales, Australia.