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Background: Terminalia ferdinandiana (Kakadu plum) is an endemic Australian plant with an extremely high antioxidant capacity. The fruit has long been used by the first Australians as a nutritional food and as a medicine and recent studies have reported its potent growth inhibitory activity against a broad panel of bacteria. Despite this, T. ferdinandiana extracts are yet to be tested for the ability to inhibit the growth of Bacillus anthracis. Materials and Methods: Solvent extracts were prepared using both the fruit and leaf of Kakadu plum. The ability to inhibit the growth of B. anthracis was investigated using a disc diffusion assay. Their MIC values were determined to quantify and compare their efficacies. Toxicity was determined using the Artemia franciscana nauplii bioassay. The most potent extracts were investigated using non-targeted GC-MS head space analysis (with screening against a compound database) for the identification and characterisation of individual components in the crude plant extracts. Results: Solvent extractions of T. ferdinandiana fruit and leaf displayed good growth inhibitory activity in the disc diffusion assay against B. anthracis. Fruit ethyl acetate and methanolic leaf extracts were particularly potent growth inhibitors, with MIC values of 451 and 377 µg/mL respectively. The fruit methanolic and chloroform extracts, as well as the aqueous leaf extracts also were good inhibitors of B. anthracis growth, albeit with lower efficacy (MIC values of 1800 and 1414 µg/mL respectively). The aqueous fruit extract and leaf chloroform extracts had only low inhibitory activity. All other extracts were completely devoid of growth inhibitory activity. Furthermore, all of the extracts with growth inhibitory activity were nontoxic in the Artemia fransiscana bioassay, with LC50 values >1000 µg/mL. Non-biased GC-MS phytochemical analysis of the most active extracts (fruit ethyl acetate and methanolic leaf) putatively identified and highlighted several compounds that may contribute to the ability of these extracts to inhibit the growth of B. anthracis. Conclusions: The low toxicity of the T. ferdinandiana fruit ethyl acetate and methanolic leaf extracts, as well as their potent growth inhibitory bioactivity against B. anthracis, indicates their potential as medicinal agents in the treatment and prevention of anthrax. [ABSTRACT FROM AUTHOR]

Introduction: Anthrax is a severe acute disease caused by Bacillus anthracis infections. If untreated, it often results in mortality. Many Terminalia spp. have documented therapeutic properties as general antiseptics, inhibiting the growth of a wide variety of bacterial species. This study examines the ability of selected Australian Terminalia spp. extracts to inhibit B. anthracis growth. Methods:Solvent extracts were prepared from Terminalia carpentariae and Terminalia grandiflora plant material and investigated by disc diffusion assay for the ability to inhibit the growth of an environmental strain of B. anthracis. Their MIC values were determined to quantify and compare their efficacies. Toxicity was determined using the Artemia franciscana nauplii bioassay. The most potent extracts were analysed by GC-MS headspace analysis. Results: T. carpentariae and T. grandiflora leaf, fruit and nut solvent extractions displayed good growth inhibitory activity against B. anthracis. Methanolic T. carpentariae leaf and T. grandiflora nut extracts were particularly potent growth inhibitors, with MIC values of 74 and 155 µg/mL respectively. The T. carpentariae leaf ethyl acetate extract was also a good inhibitor of B. anthracis growth (MIC 340 µg/mL). All other extracts were substantially less potent growth inhibitors. Interestingly, the T. carpentariae leaf extracts with growth inhibitory activity were nontoxic in the Artemia fransiscana bioassay, with LC50 values >1000 µg/mL. In contrast, the LC50 value 740 µg/mL reported for the methanolic T. grandiflora nut extract indicates low-moderate toxicity. Non-biased GC-MS phytochemical analysis of the most active extracts (methanolic T. carpentariae leaf and T. grandiflora nut) putatively identified and highlighted several compounds that may contribute to the ability of these extracts to inhibit the growth of B. anthracis. Conclusion: The growth inhibitory activity of the methanolic T. carpentariae leaf and T. grandiflora nutextracts against B. anthracis indicates their potential for the treatment and prevention of anthrax. Furthermore, the lack toxicity of the T. carpentariae leaf and the low-moderate toxicity of the T. grandiflora nut extract, indicates that their use may extend to all forms of the disease (cutaneous, inhalation or gastrointestinal). [ABSTRACT FROM AUTHOR]

Background: High antioxidant capacities have been linked to the treatment and prevention of several cancers. Recent reports have identified several native Australian fruits with high antioxidant capacities. Despite this, several of these species are yet to be tested for anticancer activity. Materials and Methods: Solvent extracts prepared from high antioxidant native Australian fruits were analyzed for antioxidant capacity by the di (phenyl)-(2,4,6-trinitrophenyl) iminoazanium free radical scavenging assay. Antiproliferative activities against CaCo2 and HeLa cancer cells were determined by a multicellular tumor spheroid-based cell proliferation assay. Toxicity was determined by Artemia franciscana bioassay. Results: Methanolic extracts of all plant species displayed high antioxidant contents (equivalent to approximately 7-16 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. In contrast, the ethyl acetate, chloroform, and hexane extracts of most species (except lemon aspen and bush tomato) had lower antioxidant contents (below 1.5 mg of vitamin C equivalents per gram of plant material extracted). The antioxidant contents correlated with the ability of the extracts to inhibit proliferation of CaCo2 and HeLa cancer cell lines. The high antioxidant methanolic extracts of all species were potent inhibitors of cell proliferation. The methanolic lemon aspen extract was particularly effective, with IC50 values of 480 and 769 μg/mL against HeLa and CaCo2 cells, respectively. In contrast, the lower antioxidant ethyl acetate and hexane extracts (except the lemon aspen ethyl acetate extract) generally did not inhibit cancer cell proliferation or inhibited to only a minor degree. Indeed, most of the ethyl acetate and hexane extracts induced potent cell proliferation. The native tamarind ethyl acetate extract displayed low-moderate toxicity in the A. franciscana bioassay (LC50 values below 1000 μg/mL). All other extracts were nontoxic. A total of 145 unique mass signals were detected in the lemon aspen methanolic and aqueous extracts by nonbiased high-performance liquid chromatography-mass spectrometry analysis. Of these, 20 compounds were identified as being of particular interest due to their reported antioxidant and/or anticancer activities. Conclusions: The lack of toxicity and antiproliferative activity of the high antioxidant plant extracts against HeLa and CaCo2 cancer cell lines indicates their potential in the treatment and prevention of some cancers. [ABSTRACT FROM AUTHOR]

Introduction: Clostridium perfringens is the etiological agent of clostridial myonecrosis and enteritis necroticans. Infections result in exotoxin production, tissue necrosis and unless promptly treated, may result in death. Terminalia ferdinandiana (Kakadu plum) fruit has documented therapeutic properties as a general antiseptic agent. Fruit extracts have been reported to inhibit the growth of an extensive panel of pathogenic bacteria. Leaf extracts have also been shown to block the growth of several bacterial species associated with autoimmune inflammatory diseases. Methods: T. ferdinandiana fruit and leaf solvent extracts were investigated for growth inhibitory activity by disc diffusion assay against a clinical strain of Clostridium perfringens. Their MIC values were determined to quantify and compare their efficacies. Toxicity was determined using the Artemia franciscana nauplii bioassay. Active extracts were analysed by non-targeted HPLC-QTOF mass spectroscopy (with screening against 3 compound databases) for the identification and characterisation of individual components in the crude plant extracts. Results: Methanolic and aqueous T. ferdinandiana fruit and leaf extracts, as well as the leaf ethyl acetate extract, displayed growth inhibitory activity in the disc diffusion assay against C. perfringens. The leaf extracts were generally more potent growth inhibitors than the corresponding fruit extracts, although the aqueous fruit extract had substantially greater efficacy than the aqueous leaf extract. The methanolic and ethyl acetate leaf extracts were particularly potent growth inhibitors, with MIC values of 206 and 117 µg/ml respectively. The fruit methanolic extract also displayed good efficacy, with an MIC of 716 µg/ml. In contrast, the chloroform and hexane extracts of both fruit and leaf were completely devoid of growth inhibitory activity. All T. ferdinandiana extracts were either nontoxic or of low toxicity in the Artemia fransiscana bioassay. Non-biased phytochemical analysis of the methanolic and ethyl acetate leaf extracts revealed the presence of high relative levels of a diversity of galloand ellagi- tannins. Conclusion: The low toxicity of the T. ferdinandiana extracts and the potent growth inhibitory bioactivity of the leaf methanolic and ethyl acetate extracts against C. perfringens indicates their potential as medicinal agents in the treatment and prevention of clostridial myonecrosis and enteritis necroticans. Metabolomic profiling studies indicate that these extracts contained a diversity of tannins. [ABSTRACT FROM AUTHOR]