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Essential oils were extracted by hydrodistillation from the traditional Australian medicinal plant Eremophila bignoniiflora, characterized chemically and then screened for bioactivity. Characterization and quantification were completed using gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection, respectively. Antimicrobial capacity was assessed using disc diffusion and micro-titre plate broth dilution and further characterized using thin layer chromatography followed by bioautography to assign activity to separated individual active components. Antifungal capacity was investigated using micro-titre plate broth dilution against pathogenic Trichophyton species. Free radical scavenging ability was assessed using the diphenylpicrylhydradyl reaction in methanol. The predominant components of the essential oil were fenchyl-acetate and bornyl-acetate. However, bioautography indicated antimicrobial ability to be largely linked to the less abundant, more polar constituents. Oils displayed only modest antifungal ability against pathogenic Trichophyton species associated with dermatophytosis, but moderate to high antimicrobial activity, particularly against the yeast Candida albicans and the bacteria Staphylococcus epidermidis. Essential oils exhibited relatively low free radical scavenging ability. Speculation over the role of essential oils in the traditional medicinal applications of E. bignoniiflora follows, exploring correlations between traditional use and investigated bioactivities., (Copyright © 2012 John Wiley & Sons, Ltd.)

Background: Five plants used traditionally by Australian Aboriginals and two edible native Australian fruits have been investigated for anticancer activity. The aim was to identify native Australian herbal medicines which displayed anticancer activity, with cytotoxicity to cancer cells but sparing or even proliferating normal immunological cells, and subsequently provide potentially new anticancer drug leads., Methods: Extracts and derived fractions were assayed for cell viability against a multiple myeloma cell line, RPMI-8226, in comparison to the peripheral blood mononuclear cells (PBMC) representing normal human immunological cells., Results: None of the crude extracts exhibited the desirable differential activity; however, following further fractionation of the Eremophila duttonii F. Muell. (Myoporaceae) extract, one fraction (termed F01) exhibited a greater cytotoxicity to the cancer cell line than to the normal cells., Conclusions: One fraction may potentially contain valuable compounds which may be useful for further investigation. This may focus on the identification of the bioavailable purified compounds present within these fractions or by detailed delineation of the related mechanisms of action.

Fifty-six ethanolic extracts of various parts of 39 plants used in traditional Australian Aboriginal medicine were investigated for their antibacterial activities against four Gram-positive (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus and Streptococcus pyogenes) and four Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella typhimurium) bacterial species. In a plate-hole diffusion assay, 12 extracts inhibited the growth of one or more of the bacteria, with five extracts showing broad spectrum antibacterial activity against Gram-positive bacteria. B. cereus was the most susceptible bacterium, with all 12 extracts displaying activity against this organism. Extracts from the leaves of Eremophila species (Myoporaceae) were the most active, with Eremophila duttonii exhibiting the greatest activity (against Gram-positive bacteria). The antibacterial effects of E. duttonii were further investigated by time-course growth assays which showed that significant growth inhibition was observed in cultures incubated in the presence of the extract within 1 h for B. cereus, E. faecalis and S. aureus and 2 h for S. pyogenes.

Extracts of 40 different plant species used in the traditional medicine of the Australian Aboriginal people have been investigated for antiviral activity. The extracts have been tested for activity against one DNA virus, human cytomegalovirus (HCMV) and two RNA viruses, Ross River virus (RRV) and poliovirus type 1, at non-cytotoxic concentrations. The most active extracts were the aerial parts of Pterocaulon sphacelatum (Asteraceae) and roots of Dianella longifolia var. grandis (Liliaceae), which inhibited poliovirus at concentrations of 52 and 250 microg/ml, respectively. The extracts of Euphorbia australis (Euphorbiaceae) and Scaevola spinescens (Goodeniaceae) were the most active against HCMV. Extracts of Eremophila latrobei subsp. glabra (Myoporaceae) and Pittosporum phylliraeoides var. microcarpa (Pittosporaceae) exhibited antiviral activity against RRV.