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Background: Rubus idaeus L. leaves have been used in traditional healing systems for the treatment of morning sickness, easing labour pains and for preventing miscarriage. Whilst few studies have examined the leaves of this species for therapeutic properties, the fruit have antibacterial activity against multiple bacterial pathogens. This study examines the growth inhibitory effects of R. idaeus leaf extracts, both alone and in combination with conventional antibiotics against bacterial triggers of selected autoimmune inflammatory diseases. Results: Rubus idaeus leaf extracts displayed noteworthy antibacterial activity against several bacterial triggers of autoimmune diseases. The methanolic, aqueous and ethyl acetate extracts were particularly good inhibitors of P. mirabilis, A. baylyi and P. aeruginosa growth, with MIC values as low as 53 µg/mL. Combining the extracts with conventional antibiotics potentiated the inhibitory activity for several combinations containing chloramphenicol or gentamicin against A. baylyi. Interestingly, the other combinations were generally non-interactive and no antagonistic interactions were detected, indicating that all combinations can be used without decreasing the efficacy of the therapy. None of the individual components (or the combinations) were toxic in the ALA assay. Conclusion: Rubus idaeus leaf extracts have potential for the prevention and treatment of rheumatoid arthritis and multiple sclerosis when used alone. Furthermore, some combinations of the extracts and conventional antibiotics had greater potency against the bacterial triggers of multiple sclerosis, indicating they may be beneficial for prophylactic therapy in individuals genetically predisposed to that disease [ABSTRACT FROM AUTHOR]

Introduction: An increase in antibiotic resistance and a corresponding decrease in antimicrobial discovery have directed researchers towards alternative therapies, including plant based medicines. However, synergistic combinations of plant extracts with conventional antibiotics may be a far more effective approach in overcoming resistance and potentiating the activity of antibiotics that are otherwise ineffective against resistant bacterial strains. Materials and Methods: The antibacterial activity of Arctium lappa L. root extracts was investigated by disc diffusion and quantified by liquid dilution and solid phase MIC assays. The extracts were also combined with a range of conventional antibiotics and tested against various microbial triggers of autoimmune diseases. The ΣFIC values obtained from these assays were used to determine the class of combinational effects. Toxicity was evaluated by Artemia nauplii mortality and HDF cytotoxicity assays. Results: Methanolic and ethyl acetate A. lappa root extracts showed good inhibitory activity against several gastrointestinal bacterial pathogens. They were particularly good inhibitors of S. sonneii and B. cereus, with MIC values in the range 150-250μg/mL. The aqueous extract was also a noteworthy inhibitor of B. cereus growth. Of further interest, some combinations of the A. lappa root extracts and conventional antibiotics potentiated bacterial growth inhibition compared to the individual components. Four synergistic and five additive interactions were noted. Notably, no antagonistic interactions were evident, indicating that all combinations could be used without decreasing the antibacterial activity of the components. All extracts were non-toxic in the ALA and HDF assays. Conclusion: Arctium lappa root extracts have potential as inhibitors of bacterial gastrointestinal pathogens. Furthermore, extract components may also potentiate the activity of some antibiotics that are relatively ineffective alone. Isolation and identification of these compounds may be beneficial in drug design against several gastrointestinal bacterial pathogens. [ABSTRACT FROM AUTHOR]

Introduction: Terminalia arjuna (Roxb.) Wight and Arn. is a southern Asian plant commonly used in Ayurveda to treat multiple conditions, including for the treatment of inflammation, and as a general antimicrobial agent. Despite this, few studies have tested this species for the ability to block the growth of bacterial triggers of some autoimmune inflammatory diseases. Furthermore, the ability of T. arjuna to potentiate the activity of conventional antibiotics is yet to be investigated. Materials and Methods: The minimum inhibitory concentration of the extracts and extract-antibiotic combinations was determined by disc diffusion and liquid dilution MIC methods. Fractional inhibitory concentration values were calculated to evaluate the combinational effect of combinations of extracts and conventional antibiotics. When synergistic interactions were detected, isobologram analysis was used to determine the ideal ratios for synergy. Toxicity was evaluated by Artemia nauplii mortality and HDF cell viability assays. Results: Methanolc, aqueous and ethyl acetate T. arjuna extracts were good inhibitors of P. mirabilis and K. pneumoniae growth when tested alone. The methanolic and aqueous extracts also synergised the inhibitory activity of ciprofloxacin against P. mirabilis and K. pneumoniae when used in combination. Additionally, numerous additive combinational effects were noted. T. arjuna chloroform extract was also a moderate inhibitor of a multi-drug resistant P. aeruginosa strain when tested alone, but did not potentiate the activity of any of the conventional antibiotics tested. All extracts and extract-antibiotic combinations were nontoxic in the Artemia nauplii mortality and HDF proliferation assays, indicating their suitability for therapeutic use. Conclusion: T. arjuna extracts have potential as inhibitors of bacterial triggers of selected autoimmune inflammatory diseases. Furthermore, T. arjuna extracts potentiate the activity of ciprofloxacin against P. mirabilis and K. pneumoniae and therefore may be beneficial in drug design against these bacteria. [ABSTRACT FROM AUTHOR]

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, Australian native plants have been relatively neglected. Heritiera actinophyllum (F.M.Bailey) Kosterm. is a rainforest tree that is native to eastern coastal regions of Australia. Material from this species has not yet been examined for antibacterial properties against human pathogens. Materials and Methods: The ability of H. actinophyllum leaf extracts 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: H. actinophyllum methanolic and aqueous extracts were ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were non-toxic or of low toxicity following 24 h exposure. Conclusion: The H. actinophyllum leaf extracts lacked growth inhibitory bioactivity against a panel of pathogenic bacteria and were nontoxic in the Artemia nauplii assay. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, and virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

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, Australian native plants have been relatively neglected. Mirbelia oxylobioides F. Muell. is a native Australian shrub of the family Fabaceae. Very few studies have yet examined species for antibacterial properties against human pathogens. Methods: The ability of M. oxyloboides leaf extracts 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: M. oxyloboides methanolic and aqueous extracts were ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were non-toxic or of low toxicity following 24 h exposure. Conclusion: The M. oxyloboides leaf 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. [ABSTRACT FROM AUTHOR]

Introduction: Trachyspermum ammi leaves and seeds have been used as dietary supplements and to treat multiple pathogenic diseases in several traditional healing systems. Despite this, their therapeutic properties have been poorly studied. Methods: Chloroform, ethyl acetate, hexane, methanol and water extracts of T. ammi were prepared and tested and the activity was compared to that of standard antibiotics for their in vitro antibacterial activity against ten human bacterial pathogens. The antibacterial activity was studied by standard disc diffusion assays and the activity was recorded as zones of inhibition. Results: All T. ammi seed extracts were ineffective at inhibiting the growth of all of the gram-positive and gram-negative bacteria pathogens screened against. Conclusion: Despite their use in traditional healing systems to treat some pathogenic diseases, T. ammi seed extracts were completely ineffective bacterial growth inhibitors. However, these extracts were screened against a limited panel of bacteria and further testing against other pathogens is required. [ABSTRACT FROM AUTHOR]

Introduction: Alphitonia excelsa (Fenzl) Benth. is a large tree that is native to the east coast and northern regions of Australia. Decoctions and infusions produced from the leaves were used by the first Australians to treat a variety of bacterial diseases. Despite this, A. excelsa leaf extractions have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of A. excelsa leaf extractions was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Polar to mid-polarity A. excelsa leaf solvent extractions inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited by the A. excelsa leaf extracts to approximately the same extent. The methanolic extracts were the most potent growth inhibitor against all bacteria tested. The methanolic, aqueous and ethyl acetate A. excelsa leaf extracts were particularly potent inhibitors of P. mirabilis growth, with MIC values as low as 118µg/mL for the methanolic extract. A. hydrophilia, E. coli, K. pneumonia, S. marcenscens and B. cereus were also particularly susceptible to the methanolic extract, with MIC values generally substantially <1000 µg/mL. The antibacterial activity of the methanolic A. excelsa leaf extract was further investigated by growth time course assays which showed significant growth inhibition in cultures of P. mirabilis and B. cereus within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusion: The lack of toxicity of the A. excelsa leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate the traditional usage of this species to treat bacterial diseases and indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: Brachychiton acerifolius (A.Cunn. ex G.Don) Macarthur and C. moore is a large tree that is native to subtropical regions of the east of Australia. Decoctions and infusions produced from the leaves of the related species Brachychiton diversifolius were used by the first Australians to treat a variety of bacterial diseases. Despite this, B. acerifolius leaf and flower extracts have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of B. acerifolius leaf and flower extracts was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic B. acerifolius leaf and flower extracts inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gramnegative bacteria was inhibited by the B. acerifolius leaf and flower extracts, although the gram negative bacteria were substantially more susceptible to the extracts than the gram positive bacteria were. The leaf extracts were more potent growth inhibitors than the flower extracts against all bacteria tested. The B. acerifolius leaf extract was a strong inhibitor of A. faecalis, K. pneumonia, P. fluorescens, S. newport, S. sonnei, B. cereus, S. aureus and S. pyogenes growth, with MIC values substantially <1000µg/mL. The antibacterial activity of the methanolic B. acerifolius leaf extract was further investigated by growth time course assays which showed significant growth inhibition in cultures of P. fluorsecens and B. cereus within 1hr of exposure. Both extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusion: The lack of toxicity of the B. acerifolius leaf and flower extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate the traditional usage of this species to treat bacterial diseases and indicates their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: Podocarpus latifolius (Thunb.) R.Br. ex Mirb. is a large tree that is native to southern Africa. This species has been used extensively for multiple therapeutic purposes across the southern part of the African continent. Despite this, P. latifolius leaf extracts have not been rigorously examined growth inhibitory properties against many bacteria, including the bacterial triggers of autoimmune inflammatory diseases. Materials and Methods: The antimicrobial activity of P. latifolia leaf solvent extractions was investigated by disc diffusion and growth time course assays against some bacterial triggers of rheumatoid arthritis and ankylosing spondylitis. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous P. latifolia leaf extracts were good inhibitors of P. mirabilis and K. pneumoniae. The inhibitory activity of both extracts was particularly noteworthy against the bacterial trigger of ankylosing spondylitis (K. pneumonia), with MICs of 343 and 557 µg/mL determined for the methanolic and aqueous extracts respectively. The extracts also displayed noteworthy activity against a bacterial trigger of rheumatoid arthritis (P. mirabilis), with MICs of 580 and 634 µg/mL respectively. The antibacterial activity of the methanolic and aqueous P. latifolia leaf extracts were further investigated by growth time course assays, which showed significant growth inhibition in cultures of P. mirabilis and K. pneumoniae within 1 hr of exposure. The extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for prophylactic use in preventing these autoimmune inflammatory diseases. Conclusion: The lack of toxicity of the P. latifolia leaf extracts and their growth inhibitory bioactivity against the bacterial triggers of rheumatoid arthritis and ankylosing spondylitis indicate their potential in the development of new therapies targeting the onset of these diseases. [ABSTRACT FROM AUTHOR]

Introduction: An increase in antibiotic resistance and a corresponding decrease in antimicrobial discovery have directed researchers towards alternative therapies, including plant-based medicines. However, synergistic combinations of plant extracts with conventional antibiotics are a far more effective approach in overcoming resistance and potentiating the activity of antibiotics that are otherwise ineffective against resistant bacterial strains. Methods: In this study, Petalostigma spp. (native Australian medicinal plants) extracts were combined with a range of conventional antibiotics and tested against various microbial triggers of autoimmune diseases. The fruit and leaves were extracted separately with solvents of varying polarity and investigated for the ability to inhibit bacterial growth using disc diffusion and liquid dilution MIC techniques. Results: The methanolic and water extracts showed low to moderate inhibitory activity against several microbes. However, combinations of the mid-low polarity extracts with conventional antibiotics proved significantly more effective in inhibiting the growth of Proteus mirabilis and Acinetobacter baylyi (bacterial triggers of rheumatoid arthritis and multiple sclerosis respectively). In total, 14 different combinations proved to be synergistic. Notably, two antibiotics (chloramphenicol and erythromycin) with no inhibitory activity against P. mirabilis alone were shown to have substantial activity when tested in combination with Petalostigma spp. extracts. Conclusion: Although the mechanisms of synergy are still unclear, studies indicate that compounds within Petalostigma spp. may mimic the actions of resistance modifying agents, thus potentiating the activity of several antibiotics that are relatively ineffective alone. Isolation of these agents may be highly beneficial in drug design against several bacteria including the microbial triggers of rheumatoid arthritis and multiple sclerosis. [ABSTRACT FROM AUTHOR]

Introduction: The recent development of extensively antibiotic resistant bacteria has necessitated the search for novel anti-bacterial compounds. An examination of aromatic plants and traditional medicines is an attractive option for drug discovery. Phragmites australis (Cav.) Trin. Ex Steud. Reed is native to many regions globally, including Australia. It has yet to be tested for antibacterial activity. Materials and Methods: The ability of P. australis leaf extracts 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: P. australis leaf methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were nontoxic in the Artemia nauplii bioassay following 24 hr exposure. Conclusion: P. australis leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: Eupomatia laurina are trees native to Australia and Papua New Guinea. The fruit of this species are consumed as a bushfood. Infusions and decoctions produced from leaves and bark have reputed antiseptic properties and were used traditionally to treat a variety of bacterial diseases. Despite this, E. laurina fruit solvent extractions have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of E. laurina fruit solvent extractions was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous E. laurina fruit extracts inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited by the E. laurina fruit extracts to approximately the same extent. With some noteable exceptions, the methanolic extracts were generally more potent than the aqueous extracts. The methanolic and aqueous E. laurina fruit extracts were particularly potent inhibitors of P. mirabilis growth, with MIC values as low as 83 µg/mL (aqueous extract against the P. mirabilis clinical isolate). The antibacterial activity of the methanolic E. laurina fruit extract was further investigated by growth time course assays which showed significant growth inhibition in cultures of K. pneumoniae and P. mirabilis within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusions: The lack of toxicity of the E. laurina fruit extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate the traditional usage of these species to treat bacterial diseases and indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: A. auriculiformis, A. disparrima and A. leptoloba are native Australian Acacia spp. which were used as both foods and medicines by the first Australians. Infusions and decoctions produced from leaves and bark have reputed antiseptic properties and were used traditionally to treat a variety of bacterial diseases. Despite this, Australian Acacia spp. solvent extractions have not been rigorously examined for antibacterial properties against food spoilage and food poisoning bacteria. Methods: The antimicrobial activity of A. auriculiformis, A. disparrima and A. leptoloba leaf extracts extractions was investigated by disc diffusion and growth time course assays against a panel of food spoilage and food poisoning bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: A. auriculiformis, A. disparrima and A. leptoloba leaf extracts inhibited the growth of a wide range of bacterial species which cause food spoilage and food poisoning. A. auriculiformis extracts were generally more potent growth inhibitors than extracts prepared from the other species, although A. disparrima extracts were also potent inhibitors of bacterial growth. With few exceptions, the methanolic extracts were more potent growth inhibitors than the other solvent extractions. The methanolic A. auriculiformis leaf extract was a particularly potent inhibitor of K. pneumoniae and P. mirabilis, B. cereus and S. aureus growth, with MIC values of 97, 132, 178 and 109 µg/mL respectively. This extract was also a good inhibitor of A. faecalis, A. hydrophilia and S. newport growth (MIC's <1000 µg/mL range). The A. disparrima extracts had a similar, albeit slightly less potent activity profiles. In contrast, the A. leptoloba leaf extracts were substantially less potent. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for use as natural food preservatives. Conclusions: The lack of toxicity of the A. auriculiformis, A. disparrima and A. leptoloba leaf extracts and their growth inhibitory bioactivity against a panel of food spoilage and food poisoning bacteria indicate their potential in the development of natural food preservatives. [ABSTRACT FROM AUTHOR]

Introduction: B. myrtifolia and S. anisatum are native Australian trees with uses as traditional medicines and bushfoods. Essential oils produced from leaves of these species have reputed antiseptic properties. Despite this, B. myrtifolia and S. anisatum leaf solvent extractions have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of aqueous and methanolic leaf extracts of B. myrtifolia and S. anisatum was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous B. myrtifolia and S. anisatum leaf extracts inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited the B. myrtifolia and S. anisatum extracts to approximately the same extent. In general, S. anisatum extracts were more potent inhibitors of bacterial growth than were the B. myrtifolia extracts, and (with some noteable exceptions) the methanolic extracts were generally more potent than the aqueous extracts. The B. myrtifolia and S. anisatum extracts were particularly potent inhibitors of P. mirabilis growth, with MIC values as low as 105 µg/mL (aqueous S. anisatum extract). The antibacterial activity of the methanolic B. myrtifolia and S. anisatum extracts were further investigated by growth time course assays which showed significant growth inhibition in cultures of E. coli, K. pneumpniae and P. mirabilis within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusions: The lack of toxicity of the B. myrtifolia and S. anisatum extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate Australian Aboriginal usage of these species as antiseptic agent and indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Background: Plants of the genus Acaciahave been used by Australian Aborigines to treat a variety of conditions including bacterial pathogens and inflammation. Despite this, many Acacia spp. have not been evaluated for the ability to inhibit the growth of bacterial triggers of autoimmune inflammatory diseases. This study evaluated the effects of Acacia disparrima and Acacia leiocalyx leaf extracts alone and in combination against some bacterial triggers of rheumatoid arthritis, ankylosing spondylitis and multiple sclerosis. Results: Acacia disparrima and Acacia leiocalyx leaf extracts displayed noteworthy antibacterial activity against several bacterial triggers of autoimmune diseases. The methanolic extracts were particularly good inhibitors of P. mirabilis, K. pneumoniae, and A. baylyi with MIC values <1000µg/mL, but were ineffective against P. aeruginosa. Furthermore, combining the extracts with conventional antibiotics resulted in significant potentiation of the inhibitory activity for some combinations. Interestingly, all of the synergistic interactions contained tetracycline as the antibiotic component, whilst all of the antagonistic combinations contained either gentamicin or ciprofloxacin as the antibiotic component. None of the individual components (nor the combinations) were toxic in the ALA assay. Conclusion: The majority of combinational effects were either additive or indifferent, thereby alleviating some concern related to the concurrent use of A. disparrima and A. leiocalyx whilst also taking conventional antibiotics. A few notable combinations were identified, indicating the need for further in vivo testing. [ABSTRACT FROM AUTHOR]

Cock.: Medicinal Plant Images 144 Pharmacognosy Communications, Vol 11, Issue 2, Apr-Jun, 2021 5. A multifaceted peer reviewed journal in the field of Pharmacognosy and Natural Products www.phcogcommn.org Medicinal Plant Images Pharmacognosy Communications, Vol 11, Issue 2, Apr-Jun, 2021 143 Ian Edwin Cock 1,2,* 1 Environmental Futures Research Institute, Nathan Campus, Griffith University, 170 Kessels Rd, Nathan, Brisbane, Queensland 4111, AUSTRALIA. Email id: i.cock@griffith.edu.au DOI: 10.5530/pc.2021 .2.27 Medicinal Plant Images Figure 2: Scaevola spinescens (commonly known as currant bush, maroon bush and prickly fanflower) is an endemic Australian plant which is distributed in arid areas of the Australian continent, particularly in the western regions. [Extracted from the article]

Background: Recent declines in new antibiotic discovery and the increase in antibiotic resistance have resulted in failing against bacterial pathogens. To develop novel antibiotic therapies, medical researchers have begun to focus on traditional therapies. Combinational therapies consisting of medicinal plants and conventional antibiotics may reactivate current drugs that are otherwise ineffective against antibioticresistant bacteria. Terminalia sericea Burch. Ex DC, Terminalia prunioides Laws. and Terminalia gazensis Bak. f. are native South African plants with antimicrobial properties. However, combinations of Terminalia sericea, Terminalia prunioides and Terminalia gazensis with conventional antibiotics are yet to be evaluated for growth inhibitory activity against gastrointestinal pathogens. Methods: Terminalia spp. leaves were extracted with solvents of varying polarity. Antimicrobial screening was performed using disc diffusion and broth microdilution assays. Toxicity was measured using Artemia franciscana nauplii lethality assays. Results: All extracts (except the T. sericea extracts) showed low to moderate inhibitory activity against B. cereus and E. faecalis, A. faecalis, A. hydrophilia, S. sonnei and S. newport in both the disc diffusion and liquid dilution assay. Twenty-three extract/antibiotic combinations produced synergy, 26 were additive, 24 were non-interactive and seven were antagonistic. Most of the antagonist interactions occurred in combinations containing gentamicin. All extracts were either non-toxic or of low toxicity in the Artemia bioassay. Conclusion: Terminalia spp. extracts may mimic the actions of a resistance modifying agents, enhancing the activity of several antibiotics that are relatively ineffective alone. Further studies are required to identify the bioactive and potentiating components and their mechanisms of action. [ABSTRACT FROM AUTHOR]

Background: Terminalia ferdinandiana Exell. fruit have been used by the First Australians as a nutritious food and as a medicine for thousands of years. The antibacterial properties of T. ferdinandiana fruit extracts are well reported. However, the therapeutic potential of plants growing in different locations and environmental conditions have not previously been compared. Aim: This study compares the antibacterial efficacy of fruit harvested from two distinct locations in Australia and correlates these activities with their physiochemical properties. Materials and Methods: The growth inhibitory activity of the T. ferdinandiana fruit extracts were evaluated using solid phase disc diffusion and liquid microdilution MIC assays. Artemia nauplii bioassays were used to screen and compare the extracts from both locations. Results: The T. ferdinandiana extracts prepared from fruits sourced from the two distinct regions of Australia inhibited the growth of the panel of bacteria screened, including a highly antibiotic MRSA strain. In general, the methanolic extracts were substantially better inhibitors of bacterial growth than the aqueous extracts, and extracts prepared using the Northern Territory (NT)-derived fruit were substantially more potent than the Western Australian (WA) fruit extracts. MICs substantially <1000 μg/mL were noted for the NT methanolic fruit extract against the reference S. aureus and MRSA bacterial strains respectively. The potency of this extract against the MRSA strain indicates that this extract may function via a distinct mechanism compared to the standard antibiotics tested. Interestingly, the greater antibacterial potency of the NT fruit extracts correlated to high ascorbic acid levels, indicating that the antibacterial mechanism may involve modulation of the redox state. All extracts were nontoxic in the Artemia nauplii toxicity assay, indicating their safety for therapeutic usage. Conclusion: The T. ferdinandiana fruit extracts prepared from both NT and WA each had noteworthy antibacterial activity, although greater activity was noted for the NT fruit extracts. This activity correlated with the antioxidant/ascorbic acid content of the extracts. All extracts were also nontoxic in the Artemia nauplii bioassay, although future studies using mammalian cell lines are required to confirm their safety for therapeutic use. [ABSTRACT FROM AUTHOR]

Introduction: An increase in antibiotic resistance and a corresponding decrease in antimicrobial discovery have directed researchers towards alternative therapies, including plant based medicines. However, synergistic combinations of plant extracts with conventional antibiotics may be a far more effective approach in overcoming resistance and potentiating the activity of antibiotics that are otherwise ineffective against resistant bacterial strains. Methods: The antibacterial activity of Arctium lappa L. root extracts was investigated by disc diffusion and quantified by liquid dilution and solid phase MIC assays. The extracts were also combined with a range of conventional antibiotics and tested against various microbial triggers of autoimmune diseases. The ΣFIC values obtained from these assays were used to determine the class of combinational effects. Toxicity was evaluated by Artemia nauplii mortality and HDF cytotoxicity assays. Results: Methanolic and ethyl acetate A. lappa root extracts showed good inhibitory activity against several microbial triggers of autoimmune inflammatory diseases, including P. mirabilis, P. vulgaris and A. baylyi. The aqueous extract was also a noteworthy inhibitor of A. baylyi growth. Of further interest, some combinations of the A. lappa root extracts and conventional antibiotics potentiated bacterial growth inhibition compared to the individual components alone. One synergistic and six additive interactions were noted. Notably, no antagonistic interactions were evident, indicating that all combinations could be used without decreasing the antibacterial activity of the components. All extracts were nontoxic in the ALA and HDF assays. Conclusion: Arctium lappa L. root extracts have potential as inhibitors of bacterial triggers of selected autoimmune inflammatory diseases. Furthermore, extract components may also potentiate the activity of three antibiotics that are relatively ineffective alone. Isolation and identification of these compounds may be beneficial in drug design against several bacteria, including the microbial triggers of rheumatoid arthritis and multiple sclerosis. [ABSTRACT FROM AUTHOR]

Images of the medicinal plants rosemary Rosemarinus officinalis L. (Lamiaceae) and wild garlic Tulbaghia violaceae Harv. are presented.

Introduction: Eucalyptus baileyana (Bailey's stringy bark) and Eucalyptus major (Queensland grey gum) have been previously used as antimicrobials against a variety of ailments. This study evaluated the effectiveness of E. baileyana and E. major as inhibitory agents against Shewanella putrefaciens, a bacterium widely associated with fish spoilage. Methodology: E. baileyana and E. major extracts were prepared using the leaves of each plant with methanol or water as the extraction solvent. Growth inhibition and minimal inhibitory concentrations were determined against S. putrefaciens through disc diffusion assays. MIC values were subsequently quantified to evaluate the extracts efficacies as antibacterial agents. Finally, the toxicity of each extract was determined using the Artemia franciscana nauplii bioassay. Results: E. baileyana aqueous and methanolic leaf extracts inhibited the growth of S. putrefaciens in the disc diffusion assay, with MIC values of 1411 and 1221 μg/mL respectively. Similarly, E. major leaf extracts also showed growth inhibition of S. putrefaciens, with MIC values of 1686 μg/mL for the aqueous extract, and 1160 μg/mL for the methanolic extract. However, toxicity studies of the extracts revealed that all extracts were toxic and likely unsuitable for human consumption (LC50 values 455-1146 μg/mL) as determined by the Artemia franciscana bioassay. Conclusion: While the E. baileyana and E. major leaf extracts were effective in preventing microbial growth, given their relatively high levels of toxicity, they would not be suitable for use as a preservative in the prevention of fish spoilage. However, the antibacterial capacity of the extracts indicates that the extracts may show promise as a surface disinfectant, and this should be investigated further. [ABSTRACT FROM AUTHOR]

Introduction: The recent development of extensively antibiotic resistant bacteria has necessitated the search for novel antibacterial compounds. An examination of aromatic plants and traditional medicines is an attractive option for drug discovery. Astrotrichia latifolia Benth. is a native Australia shrub that has yet to be tested for antibacterial activity. Methods: The ability of A. latifolia leaf extracts 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: A. latifolia leaf methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were non-toxic in the Artemia nauplii bioassay following 24 h exposure. Conclusion: A. latifolia leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: High antioxidant levels have been linked with multiple therapeutic properties, including antibacterial activity. Therefore, high antioxidant plant preparations are good targets for antibacterial testing. D. pruriens has high antioxidant capacity although it is yet to be tested for the ability to inhibit the growth of bacterial pathogens. Methods: The ability of D. pruriens fruit and leaf extracts to inhibit the growth of a panel of bacterial and fungal pathogens was investigated by disc diffusion assay. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: All D. pruriens fruit and leaf extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria, as well as fungi. The extracts were non-toxic in the Artemia bioassay following 24 h exposure. Conclusion: Despite their high antioxidant capacity, D. pruriens fruit and leaf extracts were completely ineffective bacterial and fungal growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: An increase in antibiotic resistance and a corresponding decrease in antimicrobial discovery have directed researchers towards alternative therapies, including plant based medicines. However, synergistic combinations of plant extracts with conventional antibiotics may be a far more effective approach in overcoming resistance and potentiating the activity of antibiotics that are otherwise ineffective against resistant bacterial strains. Methods: The antibacterial activity of Centella asiatica (Gotu Kola) extracts was investigated by disc diffusion and quantified by liquid dilution and solid phase MIC assays. The extracts were also combined with a range of conventional antibiotics and tested against various microbial triggers of autoimmune diseases. The SFIC values obtained from these assays were used to determine the class of combinational effects and isobologram analysis was used to determine the ideal synergistic ratio(s). Toxicity was evaluated by Artemia nauplii mortality assays. Results: The methanolic extracts showed good inhibitory activity against several microbial triggers of autoimmune inflammatory diseases, whilst the chloroform and hexane extracts were also potent inhibitors of K. pneumoniae growth. Combinations of the C. asiatica extracts with conventional antibiotics were often substantially more effective in inhibiting bacterial growth. One synergistic and 10 additive interactions were noted. Notably, the methanolic extract restored significant growth inhibitory activity to chloramphenicol and tetracycline when tested in combination against K. pneumoniae. In contrast, two antagonistic interactions were noted for combinations containing gentamycin (against A. baylyi and S. pyogenes), indicating that those combinations should be avoided when treating infections caused by those bacteria. Conclusion: C. asiatica extracts have potential as inhibitors of bacterial triggers of selected autoimmune inflammatory diseases. Furthermore, extract components may also potentiate the activity of two antibiotics that are relatively ineffective alone. Isolation of these agents may be beneficial in drug design against several bacteria, including the microbial triggers of rheumatoid arthritis, ankylosing spondylitis and multiple sclerosis. [ABSTRACT FROM AUTHOR]

Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a family are known to possess therapeutic properties. The genus Pouteria (family Sapotaceae) has a long history of medicinal usage in many areas of the world. Many species are known to have therapeutic properties, several of which have well established antibacterial bioactivities. Methods: The ability of P. australis leaf extracts 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: P. australis methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were nontoxic to Artemia nauplii following 24 hr exposure. Conclusion: Despite the taxonomic relationship with several bioactive Pouteria spp., P. australis leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a genus are known to possess therapeutic properties. The genus Ficus has a long history of medicinal usage in many areas of the world. Many species are known to have therapeutic properties, several species of which have well established antibacterial bioactivities. Methods: The ability of F. racemosa leaf extracts 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: F. racemosa methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria. The extracts were nontoxic or of low toxicity following 24 h exposure. Conclusion: Despite the close taxonomic relationship with several bioactive Ficus spp. and its therapeutic uses in traditional medicine, F. racemosa leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a genus are known to possess therapeutic properties. The genus Eucalyptus has a long history of medicinal usage by the first Australians. Many species are known to have therapeutic properties, several species of which have well established antibacterial bioactivities. Methods: The ability of Eucalyptus grandis leaf and flower extracts to inhibit the growth of a panel of bacterial and fungal pathogens was investigated by disc diffusion assay. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: E. grandis leaf and flower methanolic and aqueous extracts were completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria, as well as fungi. The extracts were nontoxic in the Artemia nauplii bioassay following 24 hr exposure. Conclusion: Despite the taxonomic relationship to several bioactive Eucalyptus spp., E. grandis leaf and flower extracts were completely ineffective bacterial and fungal growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: The development of bacterial strains that are resistant to multiple antibiotics has made the development of new antibiotics a priority for medical research. Traditional plant medicines are important leads for the discovery of new medicines. The family Agavaceae is widely used therapeutically in many areas of the world. Despite this, many members of this family are yet to be examined extensively for therapeutic properties. The species Cordyline rubra Otto and A. Dietr. was screened for antibacterial activity in this study. Methods: The ability of C. rubra leaf and fruit extracts 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: Methanolic C. rubra leaf and fruit extracts were completely ineffective at inhibiting the growth of gram-positive and gramnegative panels of bacteria. The extracts were also non-toxic or of low toxicity following 24 h exposure. Conclusion: C. rubra leaf and fruit extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a family are known to possess therapeutic properties. The family Laminaceae has a long history of medicinal usage globally. Many species are known to have therapeutic properties, several species of which have well established antibacterial bioactivities. Methods: The ability of Westringa fruticosa leaf and flower extracts to inhibit the growth of a panel of bacterial and fungal pathogens was investigated by disc diffusion assay. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: W. fruticosa leaf methanolic and aqueous extracts were both completely ineffective at inhibiting the growth of gram-positive and gram-negative panels of bacteria, as well as fungi. The extracts were non-toxic or of low toxicity in the Artemia bioassay following 24 h exposure. Conclusion: Despite the taxonomic relationship to several bioactive Laminaceae spp., W. fruticosa leaf and flower extracts were completely ineffective bacterial and fungal growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, virus and tumour cells is required. [ABSTRACT FROM AUTHOR]

Introduction: Closely related plant species often share similar secondary metabolites and bioactivities and are therefore good targets for bioactivity testing when one or more species within a genus are known to possess therapeutic properties. The genus Piper has a long history of medicinal usage in many areas of the world. Many Piper spp. are known to have therapeutic properties and several have antibacterial bioactivities. Methods: The ability of P. novae-hollandiae leaf extracts 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: P. novae-hollandiae methanolic and aqueous extracts were completely ineffective at inhibiting the growth of panels of gram-positive and gram-negative bacteria. The extracts were nontoxic or of low toxicity to Artemia nauplii following 24 h exposure. Conclusion: Despite the close taxonomic relationship with several bioactive Piper spp. and its therapeutic use by first Australians, P. novae-hollandiae leaf extracts were completely ineffective bacterial growth inhibitors. However, these extracts may have other therapeutic properties and testing against protozoa, fungi, virus and tumour cells is warranted. [ABSTRACT FROM AUTHOR]

The author discusses the criteria in selecting plants for pharmacognostic studies. The author cites that plants with a documented history of usage by traditional healers is the best choice for a good start of research while own field observations of researchers are valuable in selecting a plant species for testing. The author also notes the importance of investigating species closely related to those plants that have medicinal properties and of random selection when selecting plant species.

Introduction: Alpinia caerulea is a perennial herb which grows in coastal regions of Australia. All parts of this species are consumed as a bushfood. Furthermore, A. caerulea is taxonomically related to several plant species with well documented antimicrobial properties. Despite this, A. caerulea leaf solvent extractions have not previously been examined for antibacterial properties. Methods: The antimicrobial activity of A. caerulea leaf solvent extractions was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous A. caerulea leaf extracts inhibited the growth of a range of gram positive and gram negative bacterial species. The methanolic extract was generally a more potent growth inhibitor than the aqueous extract. The methanolic and aqueous extracts were particularly potent inhibitors of S. marcenscens growth, with MIC values as low as 188 μg/mL for the methanolic extract. P. mirabilis (MICs of 785 and 976 μg/mL for the methanolic and aqueous extracts respectively) and K. pneumoniae growth (MICs of 1167 and 924 μg/mL for the methanolic and aqueous extracts respectively) were also particularly susceptible to the A. caerulea leaf extracts. The antibacterial activity of the methanolic and aqueous A. caerulea leaf extracts was further investigated by growth time course assays which showed significant growth inhibition in cultures of S. marcenscens and P. mirabilis within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusion: The lack of toxicity of the A. caerulea leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria indicate their potential in the development of antibiotic agents. [ABSTRACT FROM AUTHOR]

Images of medicinal plants, Terminalia ferdinandiana and eucalypts are presented.

Introduction: Kunzea flavescens C.T.White & W.D.Francis is a shrub that is native to eastern Australia. Several Kunzea spp. have been used as traditional medicines against bacterial pathogens. Despite this, K. flavescens leaf extractions have not been rigorously examined for growth inhibitory properties against many bacterial pathogens. Methods: The antimicrobial activity of K. flavescens leaf solvent extractions was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic, aqueous and ethyl acetate K. flavescens leaf extracts inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited by the K. flavescens leaf extracts, although a higher proportion of gram positive species were susceptible. The methanolic extract was generally more potent than the aqueous or ethyl acetate extracts against all susceptible bacteria. The methanolic K. flavescens leaf extract was a particularly potent inhibitor of P. mirabilis and K. pneumoniae growth, with MIC values of 393 and 481 μg/mL respectively. The antibacterial activity of the methanolic K. flavescens leaf extract was further investigated by growth time course assays which showed significant growth inhibition in cultures of K. pneumoniae and P. mirabilis within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusions: The lack of toxicity of the K. flavescens leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria indicate their potential in the development of novel antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: Yersinia enterocolitica is a major cause of food poisoning through contaminated meat products, causing the acute gastrointestinal disease yersiniosis. Many Terminalia spp. have documented therapeutic properties as general antiseptics, inhibiting the growth of a wide variety of bacterial species. Despite this, Indian Terminalia spp. extracts have not been tested for the ability to inhibit the growth of Y. enterocolitica. Methods: T. arjuna, T. catappa and T. chebula extracts were extracted by maceration and the extracts were investigated by disc diffusion assay for growth inhibitory activity against a clinical strain of Y. enterocolitica. The MIC values of the extracts were determined to quantify and compare their efficacies. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: T. chebula fruit extracts displayed potent growth inhibitory activity in the disc diffusion assay against Y. enterocolitica. The methanolic and ethyl acetate T. chebula fruit extracts were particularly potent growth inhibitors, with MIC values of 85 and 64 μg/mL respectively. The aqueous fruit extract also displayed good growth inhibitory activity against Y. enterocolitica, albeit with a higher MIC value (653 μg/mL). The T. arjuna branch extract was moderately active (3000 μg/mL). All other extracts were either low efficacy, or completely devoid of growth inhibitory activity. All Indian Terminalia spp. extracts were nontoxic (LC50 values <1000 μg/mL) in the Artemia franciscana bioassay. Conclusions: The lack of toxicity and the potent growth inhibitory bioactivity of the T. chebula extracts against Y. enterocolitica indicates their potential as medicinal agents in the treatment and prevention of yersiniosis. [ABSTRACT FROM AUTHOR]

Introduction: Swainsona formosa is a legumous plant which is endemic to the arid inland regions of Australia. Several Swainsona spp. were valued by the first Australian for their antiseptic properties and were used traditionally to treat a variety of bacterial diseases. Despite this, S. formosa solvent extractions have not been rigorously examined for antibacterial properties against many bacterial pathogens. Methods: The antimicrobial activity of S. formosa leaf extracts was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: S. formosa leaf extracts inhibited the growth of a wide range of gram positive and gram negative bacteria. The methanolic extracts were generally more potent than the aqueous extracts. The methanolic and aqueous S. formosa leaf extracts were particularly potent inhibitors of A. faecalis, A. hydrophilia, K. pneumoniae, P. mirabilis, B. cereus, S. aureus and S. pyogenes growth, with MIC values substantially <1000 μg/mL and as low as 150 μg/mL against some bacteria (methanolic extract against P. mirabilis). The antibacterial activity of the methanolic and aqueous S. formosa leaf extracts was further investigated by growth time course assays which showed significant growth inhibition in cultures of all bacterial species within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for therapeutic uses. Conclusions: The lack of toxicity of the S. formosa leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: Aleurites moluccanus (L.) Willd. is a large tree with a wide global distribution. All parts of the tree have been used medicinally and the nut is consumed in a variety of cuisines. Despite this, A. moluccanus nut extracts have not been rigorously examined growth inhibitory properties against many bacteria, including the bacterial triggers of autoimmune inflammatory diseases. Methods: The antimicrobial activity of A. moluccanus nut solvent extractions was investigated by disc diffusion and growth time course assays against a panel of bacterial triggers of autoimmune diseases. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous A. moluccanus nut solvent extracts were potent inhibitors of all of the bacterial triggers of autoimmune diseases screened in this study. The methanolic extract displayed the most potent bacterial growth inhibitory activity. It was particularly potent against the bacterial triggers of rheumatoid arthritis (MICs of 438 and 215 ìg/mL against reference and clinical Proteus mirabilis strains; MIC of 187 ìg/mL against Proteus vulgaris). The methanolic extract was also a good inhibitor of K. pneumoniae and S. pyogenes growth with MICs < 1000 ìg/mL. The aqueous and ethyl acetate extracts were also potent bacterial growth inhibitors, albeit with slightly higher MIC values. The antibacterial activity of the methanolic and aqueous A. moluccanus nut extracts were further investigated by growth time course assays which showed significant growth inhibition in cultures of P. mirabilis, K. pneumpniae and S. pyogenes within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for prophylactic use in preventing these autoimmune inflammatory diseases. Conclusions: The lack of toxicity of the A. moluccanus nut extracts and their growth inhibitory bioactivity against the bacterial triggers of rheumatoid arthritis, ankylosing spondylitis and rheumatic heart disease indicate their potential in the development of new therapies targeting the onset of these diseases. [ABSTRACT FROM AUTHOR]

Introduction: Cinnamomum oliveri F. M. Bailey is a rain forest tree native to Australia. Decoctions, infusions and essential oils produced from the leaves were used traditionally to treat a variety of bacterial diseases. Despite this, C. oliveri leaf extractions have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of C. oliveri leaf extractions was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: C. oliveri leaf solvent extractions inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited by the C. oliveri leaf extracts to approximately the same extent. The methanolic extracts were generally most potent growth inhibitors. The methanolic, aqueous and ethyl acetate C. oliveri leaf extracts were particularly potent inhibitors of P. mirabilis growth, with MIC values as low as 127 µg/mL (methanolic extract). A. coli, K. pneumoniae and B. cereus were also particularly susceptible to the methanolic, aqueous and ethyl acetate extracts, with MIC values generally substantially <1000 μg/mL. The antibacterial activity of the methanolic C. oliveri leaf extract was further investigated by growth time course assays which showed significant growth inhibition in cultures of E. coli, K. pneumoniae and P. mirabilis within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for internal use as well as for topical uses. Conclusions: The lack of toxicity of the C. oliveri leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate the traditional usage of these species to treat bacterial diseases and indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Introduction: Leptospermum longifolium (C.T. White & W.D. Francis) S.T. Blake, Leptospermum petersonii Bailey and Melaleuca alternifolia (Maiden & Betche) Cheel are aromatic native Australian trees with uses as traditional medicines. Essential oils produced from leaves of these species have reputed antiseptic properties against many bacteria. Despite this, L. longifolium, L. petersonii and M. alternifolia leaf solvent extractions have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of methanolic L. longifolium, L. petersonii and M. alternifolia leaf extracts was investigated by disc diffusion and growth time course assays against a panel of pathogenic bacteria. The growth inhibitory activity was quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: The methanolic L. longifolium, L. petersonii and M. alternifolia leaf extracts inhibited the growth of a wide range of bacterial species. Growth of both gram positive and gram negative bacteria was inhibited by all extracts. The L. longifolium and L. petersonii extracts were generally more potent inhibitors of bacterial growth than was the M. alternifolia extract against most bacterial species. A. hydrophilia, C. freundi, P. mirabilis and B. cereus growth was particularly susceptible to the extracts, with MIC values as low as 147 µg/mL (inhibition of A. hydrophilia growth by the L. longifolium extract). The antibacterial activity of the L. longifolium, L. petersonii and M. alternifolia extracts were further investigated by growth time course assays, with significant growth inhibition recorded in all cultures within 1 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for therapeutic uses. Conclusions: The lack of toxicity of the methanolic L. longifolium, L. petersonii and M. alternifolia leaf extracts and their growth inhibitory bioactivity against a panel of pathogenic bacteria partially validate Australian Aboriginal usage of these species as antiseptic agents and indicate their potential in the development of antiseptic agents. [ABSTRACT FROM AUTHOR]

Background: Extracts produced from S. australe and S. luehmannii fruit and leaves are potent growth inhibitors of many bacterial pathogens. They may also inhibit the growth of malodour producing bacteria and thus be useful deodorant components, although this is yet to be tested. Methods: S. australe and S. luehmannii fruit and leaf solvent extracts were investigated by disc diffusion assays against significant bacterial contributors to axillary and plantar malodour formation. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: S. australe and S. luehmannii solvent extracts were good inhibitors of B. linens and C. jeikeium growth, with zones of inhibition up to 10 mm measured. S. australe extracts were generally better inhibitors of both bacterial species compared with the S. luehmannii extracts. Ethyl acetate extracts were particularly potent, with MIC values of 300 and 857 μg/mL for the S. australe fruit and leaf extracts respectively against B. linens, and 1000 and 311 μg/mL against C. jeikeium. The S. luehmannii fruit ethyl acetate extracts were similarly potent growth inhibitors, with MIC values of 571 and 203 μg/mL against B. linens and C. jeikeium respectively. S. australe aqueous and methanolic leaf extracts were also potent inhibitors of C. jeikeium (MIC's of 285 and 306 μg/mL respectively). All other extracts had moderate or low inhibitory activity. All of the most potent ethyl acetate extracts were nontoxic in the Artemia franciscana bioassay. In contrast, the methanolic and aqueous S. australe leaf extracts, as well as the aqueous and methanolic S. luehmannii fruit extracts displayed apparent toxicity. However, these results may be fallacious and instead result from the high antioxidant content of these extracts. Conclusion: The potent growth inhibition of axillary and plantar malodour producing bacteria by the Syzygium spp. extracts indicate their potential as deodorant components. [ABSTRACT FROM AUTHOR]

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]