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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 Taraxacum officinale (L.) Weber ex F.H. Wigg. root extracts was investigated by disc diffusion and quantified by liquid dilution and solid phase MIC assays against some bacterial triggers of autoimmune inflammatory diseases. The extracts were also combined with a range of conventional antibiotics and tested against various bacterial pathogens. The SFIC 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 T. officinale root extracts showed good inhibitory activity against several microbial triggers of autoimmune inflammatory diseases, including P. mirabilis, P. vulgaris and A. baylyi. Of further interest, some combinations of the T. officinale root extracts and conventional antibiotics potentiated bacterial growth inhibition compared to the individual components alone. Six synergistic and seven additive interactions were noted. Additionally, two antagonistic interactions were evident, indicating that those combinations should be avoided. All extracts were nontoxic in the ALA and HDF assays, verifying their safety for therapeutic usage. Conclusion: Taraxacum officinale 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]

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]

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]

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]

Introduction: The recent development of extensively antibiotic resistant bacteria has necessitated the search for novel antibacterial therapies. An examination of aromatic plants and traditional medicines is an attractive option for drug discovery. Terminalia sericea Burch. ex DC. is a southern African native species, which has been reported to have antibacterial activity, although the effects of storage on the activity is yet to be determined. Materials and Methods: The ability of T. sericea leaf extracts to inhibit the growth of a panel of bacterial triggers of autoimmune diseases was quantified by disc diffusion and liquid dilution MIC assays. The potency of extracts prepared using fresh and stored leaves was compared. Toxicity was examined using the Artemia franciscana nauplii bioassay. Results: The T. sericea leaf methanolic and aqueous extracts displayed noteworthy growth inhibitory activity towards all bacterial pathogens tested. However, a substantial decrease in activity was seen when extracts were prepared using leaves that had been stored for two years, indicating that the leaves become less useful therapeutically over time. All extracts were non-toxic in the Artemia nauplii bioassay following 24hr exposure. Conclusion: The T. sericea leaf extracts had noteworthy antibacterial activity, although the potency decreased substantially following storage of the leaf material. [ABSTRACT FROM AUTHOR]

Traditional medicines prepared using Terminalia species have been used globally to treat inflammation and pathogenic infections. Recent studies have demonstrated that multiple Asian and African Terminalia spp. inhibit bacterial triggers of some autoimmune inflammatory diseases, including ankylosing spondylitis. Despite this, the effects of Australian Terminalia spp. on a bacterial trigger of ankylosing spondylitis (K. pneumoniae) remain unexplored. Fifty-five extracts from five Australian Terminalia spp. were investigated for K. pneumoniae growth inhibitory activity. Methanolic, aqueous and ethyl acetate extracts of most species and plant parts inhibited K. pneumoniae growth, with varying potencies. Methanolic leaf extracts were generally the most potent bacterial growth inhibitors, with minimum inhibitory concentration (MIC) values of 66 μg/mL (T. ferdinandiana), 128 μg/mL (T. carpenteriae) and 83 μg/mL (T. petiolares). However, the aqueous leaf extract was the most potent T. grandiflora extract (MIC = 87 μg/mL). All T. catappa extracts displayed low growth inhibitory activity. The Terminalia spp. methanolic leaf extracts were examined by liquid chromatography-mass spectrometry (LC–MS) and gas chromatography-mass spectrometry (GC–MS). All contained a relative abundance of simple gallotannins (particularly gallic and chebulic acids), the flavonoid luteolin, as well as the monoterpenoids cineole and terpineol. Notably, all Terminalia spp. were non-toxic or of low toxicity in ALA and HDF toxicity assays, highlighting their potential for preventing the onset of ankylosing spondylitis and treating its symptoms once the disease is established, although this needs to be verified in in vivo systems. [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]

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: Kunzea ambigua (Sm.) Druce and Kunzea flavescens C.T. White and W.D. Francis are endemic Australian plants. Decoctions, infusions and essential oils produced from the leaves were used traditionally to treat a variety of bacterial diseases. Despite this, these species have not been rigorously examined for antibacterial properties against many pathogens. Methods: The antimicrobial activity of K. ambigua and K. flavescens essential oils and a K. ambigua hydrosol was investigated by disc diffusion and liquid dilution MIC assays against a panel of pathogenic bacteria. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: K. ambigua and K. flavescens essential oils displayed noteworthy growth inhibitory activity against A. baylyi, K. pneumonia, P. mirabilis and P. aeruginosa (MIC values substantially <1000μg/mL). Indeed, MIC values as low as 33μg/mL were noted against P. aeruginosa. Noteworthy growth inhibitory activity was also noted for the K. ambigua hydrosol against A. baylyi and P. aeruginosa. All extracts were determined to be non-toxic 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 Kunzea spp. 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: 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: The development of multi-antibiotic resistant strains of bacteria has necessitated the search for new, effective antibacterial therapies. M. lauteriana was used by Australian Aborigines as a nutritious food. However, very little research has been published on this species and the antibacterial activity of M. lauteriana leaf extracts has not yet been reported. Methods: The ability of M. lauteriana leaf extracts to inhibit the growth of gram-negative and gram-positive bacterial species was investigated by disc diffusion and growth time course assays. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: The methanolic and aqueous M. lauteriana leaf extracts were good inhibitors of the growth of both gram-positive and gram-negative bacteria. The methanolic extract was a particularly good inhibitor of K. pneumoniae and B. cereus growth, with MIC values of 728 and 515µg/mL respectively. The aqueous extract was also a good inhibitor of these bacteria (MICs of 953 and 860µg/mL respectively). Whilst the M. lauteriana leaf extracts also inhibited the growth of P. mirabilis, S. aureus and S. pyogenes, the MIC values (in the range 1000-2000µg/mL) were indicative of moderate inhibitory activity. The M. lauteriana leaf extracts were further investigated by growth time course assays against K. pneumoniae and B. cereus. Interestingly, both extracts showed significant growth inhibition within 1h of exposure against both bacterial species. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for the treatment of gram-positive bacterial infections. Conclusion: The lack of toxicity of the M. lauteriana leaf extracts and their growth inhibitory bioactivity against multiple bacteria indicate their potential in the development of new antibiotic chemotherapies. [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: Melodorum leichhardtii F.Muell. Benth. is a rainforest vine which is native to north-eastern rainforest regions of Australia. Melodorum spp. are rich in a variety of terpenoids with reported antibacterial activity. Despite this, M. leichhardtii leaf extracts have not previously been examined for bacterial growth inhibitory properties. Methods: The antimicrobial activity of a methanolic M. leichhardtii leaf extract was investigated by disc diffusion and growth time course assays against a panel of bacterial pathogens. The growth inhibitory activity was further quantified by MIC determination. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: The methanolic M. leichhardtii leaf extract was a potent inhibitor of Klebsiella pneumonia (MICs of 388µg/mL). The extract was also a low-moderate inhibitor of B. cereus growth (MICs 3678µg/mL) but was completely devoid of inhibitory activity against all other bacterial species tested. The antibacterial activity of the methanolic M. leichhardtii leaf extract was further investigated by growth time course assays that showed significant growth inhibition in cultures of K. pneumoniae 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 use in preventing diseases caused by these pathogens. Conclusion: The lack of toxicity of the M. leichhardtii leaf extracts and their growth inhibitory bioactivity against K. pneumoniae and B. cereus indicate their potential in the development of new therapies targeting these bacteria. [ABSTRACT FROM AUTHOR]

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]

Background: Embelica officinalis Gaertn. is an Indian plant which is known for its therapeutic properties. It is especially well known as a component of the Ayuverdic medicine Triphala. This study focuses on the growth inhibitory activity of E. officinalis fruit extracts against some bacterial triggers of autoimmune inflammatory diseases, both alone and in combination with conventional antibiotics. Methods: E. officinalis fruit powder was extracted with solvents of varying polarity and screened for bacterial growth inhibition by disc diffusion assay. The minimum inhibitory concentration (MIC) was quantified by both liquid dilution and disc diffusion techniques. To screen for combinatorial effects, the E. officinalis fruit extracts were combined with a range of conventional antibiotics and tested against each bacteria using a liquid dilution assay. Toxicity was examined using Artemia nauplii and HDF bioassays. Results: The ethyl acetate E. officinalis fruit extract displayed the strongest growth inhibitory activity against all of the bacterial triggers of autoimmune inflammatory disease. This extract was a particularly potent inhibitor of P. aeruginosa growth, with an MIC values as low as 264 μg/mL. The ethyl acetate extract was also a moderate to strong growth inhibitor of P. mirabilis, K. pneumonia and A. baylyi, with MIC values generally 1000-1500 μg/mL. The methanolic and aqueous extracts also inhibited the growth of all bacteria, although generally with only moderate to low activity. Whilst no synergistic interactions were detected in combinations containing the E. officinalis fruit extracts and conventional antibiotics, a number of combinations produced additive effects. These combinations are beneficial as they provide enhanced antibacterial efficacy compared to treatment with the antibiotic or extract components alone. No antagonistic interactions were detected. Therefore, use of the extracts in combination with conventional antibiotics would not compromise the antibiotics efficacy. All extracts were nontoxic in the Artemia nauplii and HDF toxicity assays, further indicating their potential for medicinal use. Conclusion: The E. officinalis fruit extracts were moderate inhibitors of the bacterial triggers of selected autoimmune inflammatory diseases. Furthermore, the extracts potentiated the activity of chloramphenicol and tetracycline against otherwise resistant bacterial strains. Isolation of the active compounds and the potentiating agents may be beneficial in antibiotic drug design. [ABSTRACT FROM AUTHOR]

Background: Roots from Glycyrrhiza glabra L. are known for their anti-inflammatory and antimicrobial properties. This study focuses on the growth inhibitory activity of G. glabra root extracts against some bacterial triggers of autoimmune inflammatory disease alone and in combination with conventional antibiotics. Methods: G. glabra root powder was extracted with solvents of varying polarity and screened for bacterial growth inhibition by disc diffusion assay. The minimum inhibitory concentration (MIC) was quantified by both liquid dilution and disc diffusion techniques. To screen for combinatorial effects, the G. glabra root extracts were combined with a range of conventional antibiotics and tested against each bacterium using liquid dilution assays. Where synergy was detected, the optimal ratios were determined using isobologram analysis. Toxicity was examined using an Artemia nauplii and HDF bioassays. Results: G. glabra root methanolic, aqueous and ethyl acetate extracts displayed antimicrobial activity against bacterial triggers of some autoimmune inflammatory diseases. The ethyl acetate extract was particularly potent, with MIC values <500 μg/mL against K. pneumoniae and A. baylyi. The aqueous extract was also a moderate inhibitor of A. baylyi. The methanolic extract had moderate inhibitory activity against all bacteria except P. aeruginosa. Of further note, the aqueous extract interacted synergistically in combination with chloramphenicol against K. pneumoniae (Σ FIC 0.49). All extracts were nontoxic in the Artemia and HDF toxicity assays, further indicating their potential for medicinal use. Conclusion: The G. glabra ethyl acetate root extract was a strong inhibitor of the growth of K. pneumoniae and A. baylyi and therefore has potential in the prevention and treatment of ankylosing spondylitis and multiple sclerosis. In addition, the aqueous root extract potentiated the inhibitory activity of chloramphenicol against a chloramphenicol resistant K. pneumoniae strain. Although the mechanisms of synergy are still unclear, compounds within the G. glabra root extracts may mimic the actions of resistance modifying agents. Isolation of these agents may be beneficial in antibiotic drug design against bacterial triggers of ankylosing spondylitis. [ABSTRACT FROM AUTHOR]

Introduction: Pseudowintera colorata (Raoul) Dandy is an evergreen shrub which is endemic to New Zealand. Decoctions, infusions and essential oils produced from the leaves were used traditionally to treat a variety of bacterial diseases. Despite this, P. colorata leaf extracts have not been rigorously examined for inhibitory activity against bacterial triggers of autoimmune inflammatory diseases. Methods: A P. colorata hydro-alcohol leaf extract was analysed for antioxidant capacity by the DPPH free radical scavenging assay. Growth inhibitory activities against bacterial species associated with initiating rheumatoid arthritis, ankylosing spondylitis, multiple sclerosis and rheumatic fever were determined by disc diffusion assay and quantified by MIC determination. Toxicity was determined by Artemia franciscana bioassay. Results: The P. colorata hydro-alcohol leaf extract displayed good DPPH radical scavenging activity, with an antioxidant capacity of 52 µg/mL ascorbic acid equivalency. The extract inhibited the growth of all of the bacterial triggers of autoimmune inflammatory diseases tested. It was a particularly potent inhibitor of A. baylyi, with MIC values as low as 427 µg/mL against the clinical strain. P. mirabilis and P. vulgaris were also highly susceptible to the P. colorata hydro-alcohol leaf extract, with MIC values of approximately 800-900 µg/mL against all strains. The extract was also a moderate growth inhibitor (MIC >1000 µg/mL) of all other bacterial strains tested. The extract was determined to be nontoxic in the Artemia franciscana nauplii bioassay with 24 h LC50 values substantially >1000 µg/mL, indicating its safety for therapeutic use. Conclusion: The lack of toxicity of the P. colorata leaf extracts and their growth inhibitory bioactivity against a panel of bacterial triggers of autoimmune inflammatory diseases indicate their potential in the prevention and treatment of these diseases in genetically susceptible individuals. [ABSTRACT FROM AUTHOR]

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: 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: Duboisia leichhardtii F.Muell. is a medium to large tree which is native to subtropical regions of eastern Australia. Duboisia spp. contain a number of psychoactive tropane and pyrrolidine alkaloids with reported antibacterial activity. Despite this, D. leichhardtii leaf extracts have not been rigorously examined for growth inhibitory properties against many bacteria, including the bacterial triggers of autoimmune inflammatory diseases. Methods: The antimicrobial activity of D. leichhardtii leaf solvent extracts 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 and growth time course assays. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: Methanolic and aqueous D. leichhardtii leaf solvent extracts were potent inhibitors of the bacterial triggers of rheumatoid arthritis and ankylosing spondylitis. The methanolic extract displayed the most potent bacterial growth inhibitory activity. It was particularly potent against P. mirabilis (MICs of 85 and 116 µg/mL against reference and clinical strains respectively) and P. vulgaris (MIC of 187 µg/mL). The methanolic extract was also a good inhibitor of K. pneumoniae growth (MICs of 143 and 118 µg/mL against reference and clinical strains respectively). The aqueous and ethyl acetate extracts were also potent bacterial growth inhibitors, albeit with higher MIC values. The antibacterial activity of the methanolic and aqueous D. leichhardtii 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 h of exposure. All extracts were determined to be nontoxic in the Artemia franciscana nauplii bioassay, indicating their safety for use in preventing these autoimmune inflammatory diseases. Conclusions: The lack of toxicity of the D. leichhardtii 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]

Background: The consumption of high antioxidant foods has been linked with a decreased incidence of some cancers and inflammatory diseases. Some high antioxidant foods also inhibit the growth of a variety of bacterial pathogens. Despite this, the high antioxidant 'superfoods' acai, cacao and maca are yet to be adequately tested for anticancer activity or the ability to inhibit the growth of bacterial triggers of autoimmune inflammatory diseases. Materials and Methods: Freeze dried acai, cacao and maca powders were extracted and tested for antimicrobial activity using a modified disc diffusion assay and the MICs were determined. Inhibitory activity against CaCo2 and HeLa cancer cell lines was evaluated using colorimetric cell proliferation assays. Toxicity was evaluated using an Artemia franciscana nauplii bioassay. Results: The acai, cacao and maca extracts displayed broad spectrum antibacterial activity, inhibiting the growth of all of the bacteria screened, although generally with only low efficacy. The ethyl acetate extracts were more potent bacterial growth inhibitors than were the corresponding methanolic and aqueous extracts. The inhibitory activity of the acai and maca ethyl acetate extracts against P. mirabilis was particularly noteworthy, with MIC values <1000 µg/mL. The aqueous and methanolic extracts of all fruits had only low bacterial growth inhibitory activity. In contrast, the aqueous extracts of cacao and maca were the most effective at inhibiting proliferation of the colorectal cancer cell line CaCo2 (aqueous maca extract IC50=1800 µg/mL) and HeLa cervical cancer cell growth, (aqueous cacao extract IC50 values 1810 µg/mL). All extracts were non-toxic, with LC50 values substantially > 1000 µg/mL. Conclusion: These studies demonstrate that the aqueous cacao and maca extracts have appreciable inhibitory activity against some cancer cell lines and that the acai and maca ethyl acetate extracts were moderate inhibitors of the growth of bacteria associated with selected autoimmune inflammatory disorders. Furthermore, the toxicity studies indicate that they are safe for therapeutic usage. All other extracts were inactive or of low activity towards the cancer and bacterial cells. [ABSTRACT FROM AUTHOR]

Introduction: High antioxidant capacities have been linked to the treatment of rheumatic diseases and also in the inhibition of microbial growth. Although Cakile maritima has a high antioxidant capacity, it is yet to be tested for the ability to inhibit the growth of the bacterial triggers of autoimmune inflammatory diseases. Methods: C. maritima solvent extracts were analysed for antioxidant capacity by the DPPH free radical scavenging assay. Growth inhibitory activities against bacterial species associated with initiating rheumatoid arthritis, ankylosing spondylitis and multiple sclerosis were determined by disc diffusion assay and quantified by MIC determination. Toxicity was determined by Artemia franciscana bioassay. Results: All C. maritima solvent extracts displayed good DPPH radical scavenging activity, although the ethyl acetate extract was particularly potent with an IC50 values of 3.4 μg/mL. The other extracts also had significant radical scavenging activity, with IC50 between 4.7 and 13.6 μg/mL. The bacterial growth inhibitory activity of the extracts correlated with their free radical scavenging activity. The ethyl acetate extract displayed the most potent growth inhibitory activity against most bacterial species. This extract was particularly potent against Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa (MIC values of 431, 559 and 777 μg/mL, respectively). The hexane extract was also a potent inhibitor of the Proteus spp., (MIC of approximately 500-800 μg/mL). The ethyl acetate extract also inhibited Klebsiella pneumoniae growth, albeit with higher MIC's (approximately 1500 μg/mL). All other C. maritima extract-bacteria combinations generally resulted in mid-low potency inhibition. All of the extracts were determined to be nontoxicin with the Artemia franciscana bioassay, with LC50 values substantially >1000 μg/mL. A total of 97 unique mass signals were detected in the C. maritima ethyl acetate extract by nonbiased GC-MS headspace analysis. A number of terpenoids which may contribute to the therapeutic bioactivities of the extract were putatively identified. Conclusion: The lack of toxicity and the inhibitory activity against microbial triggers of rheumatoid arthritis, ankylosing spondylitis and multiple sclerosis by the C. maritima ethyl acetate extract indicates its potential in the treatment and prevention of these diseases. [ABSTRACT FROM AUTHOR]

Introduction: Myrrh has been used traditionally for the inhibition of microbial growth and for the treatment of rheumatic diseases. Despite this, myrrh extracts are yet to be tested for the ability to inhibit the growth of the bacterial triggers of autoimmune inflammatory diseases. Methods: Solvent extracts prepared from commercially obtained myrrh resin were analysed for the ability to inhibit the growth of bacterial species associated with initiating rheumatoid arthritis (P. mirabilis), ankylosing spondylitis (K. pneumoniae) and multiple sclerosis (A. baylyi, P. aeruginosa) by disc diffusion assay, and quantified by MIC determination. Toxicity was determined by Artemia franciscana bioassay. The most potent inhibitory extract was 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: Methanolic myrrh extract inhibited the growth of all bacterial species tested. The growth inhibition of this extract was particularly notable against P. mirabilis and K. pneumoniae, with MIC values substantially < 1000 µg/mL for both reference and clinical bacterial strains. Indeed, the MIC values of the methanolic extract against P. mirabilis reference and clinical strains were 572 and 463 µg/mL respectively. The methanolic extract also inhibited the growth of A. baylyi (MIC approximately 3000 µg/mL) and P. aeruginosa (MIC approximately 1800 µg/mL). However, the MICs against these bacteria was indicative of only moderate inhibitory activity. The aqueous, ethyl acetate, chloroform and hexane extracts also inhibited the growth of all bacterial species, albeit with moderate (MIC values 1000-5000 µg/mL) to low efficacy (MIC values >5000 µg/mL) against all bacterial species. All myrrh extracts were non-toxicin the Artemia franciscana bioassay, with LC50 values substantially above 1000 µg/mL. Non-biased GC-MS headspace analysis of the methanolic extracti dentified a high diversity of monoterpenoids and sesquiterpenoid. Conclusion: The lack of toxicity and the inhibitory activity of the methanolic myrrh extract against microbial triggers of rheumatoid arthritis, ankylosing spondylitis and multiple sclerosis indicates its potential in the treatment and prevention of these diseases. [ABSTRACT FROM AUTHOR]

Introduction: Frankincense has been used traditionally for the inhibition of microbial growth and for the treatment of rheumatic diseases. Despite this, frankincense extracts are yet to be tested for the ability to inhibit the growth of the bacterial triggers of autoimmune inflammatory diseases. Methods: Solvent extracts prepared from commercially obtained frankincense were analysed for the ability to inhibit the growth of bacterial species associated with initiating rheumatoid arthritis (P. mirabilis), ankylosing spondylitis (K. pneumoniae) and multiple sclerosis (A. baylyi, P. aeruginosa) by disc diffusion assay, and quantified by MIC determination. Toxicity was determined by Artemia franciscana bioassay.The most potent inhibitory 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: Methanolic and aqueous frankincense extracts inhibited the growth of all bacterial species. The growth inhibition of these extracts was particularly notable against P. mirabilis and K. pneumoniae, with MIC values generally ⩽ 1000 μg/mL for both reference and clinical bacterial strains. Indeed, the MIC values of the methanolic extract against P. mirabilis, and for the aqueous extract against K. pneumonia, were as low as 59.6 and 75.2 μg/mL respectively. The methanolic and aqueous extracts also inhibited the growth of A. baylyi and P. aeruginosa. However, with the exception of the growth inhibition of A. baylyi by the aqueous extract (MIC=4313 μg/mL: moderate inhibitory activity), the MICs against these bacteria was indicative of only low inhibitory activity. The ethyl acetate, chloroform and hexane extracts also inhibited the growth of all bacterial species, albeit with low efficacy (MIC values generally >5000 μg/mL against all bacterial species). All frankincense extracts were non-toxic in the Artemia franciscana bioassay, with LC50 values substantially above 1000 μg/mL. Non-biased GC-MS headspace analysis of the methanolic and aqueous extracts putatively identified a high diversity of monoterpenoids and sesquiteriterpenoids. Conclusion: The lack of toxicity and the inhibitory activity of the methanolic and aqueous frankincense extracts against microbial triggers of rheumatoid arthritis and ankylosing spondylitis indicates their potential in the treatment and prevention of these diseases. [ABSTRACT FROM AUTHOR]

Introduction: High antioxidant capacities have been linked to the treatment of rheumatic diseases and in the inhibition of microbial growth. Recent reports have identified several native Australian culinary herbs with high antioxidant capacities. Despite this, several of these species are yet to be tested for the ability to inhibit the growth of the bacterial triggers of autoimmune inflammatory diseases. Methods: Solvent extracts prepared from selected Australian culinary herbs were analysed for antioxidant capacity by the DPPH free radical scavenging assay. Growth inhibitory activities against bacterial species associated with initiating rheumatoid arthritis and ankylosing spondylitis were determined by disc diffusion assay and quantified by MIC determination. Toxicity was determined by Artemia franciscana bioassay. Results: Methanolic extracts of most plant species displayed relatively high antioxidant contents (equivalent to approximately >10 mg of vitamin C per gram of fruit extracted). Most aqueous extracts also contained relatively high antioxidant capacities. The ethyl acetate and chloroform extracts generally had lower antioxidant capacities than the more polar extracts. In contrast, the hexane extracts of all species had low antioxidant contents (generally < 0.5 mg of vitamin C per gram of fruit extracted). Interestingly, the bacterial growth inhibitory activity of the extracts did not correlate with their antioxidant capacities. With the exception of native thyme, the herb extracts with the highest antioxidant capacities had only low antibacterial activity, with MIC values generally well in excess of 4000 µg/ml against all bacterial species. In contrast, many of the ethyl acetate extract and hexane extracts, which had low range antioxidant capacities (generally < 5 mg ascorbic acid equivalents/g extracted), had potent bacterial growth inhibitory activity with many MIC values substantially below 1000 µg/ml). The river mint ethyl acetate extract displayed toxicity in the Artemia franciscana bioassay (LC50=186 µg/mL). All other extracts were nontoxic. Conclusion: The lack of toxicity and inhibitory activity against microbial triggers of rheumatoid arthritis and ankylosing spondylitis by the Australian native culinary herb extracts indicates their potential in the treatment and prevention of these diseases. [ABSTRACT FROM AUTHOR]

Image, graphical abstract Recent increases in antibiotic resistance and corresponding decreases in the development of new antimicrobial therapies have made new antibiotic discovery a high priority. Traditional medicines have potential for antibiotic discovery, although synergistic combinations consisting of plant extracts and conventional antibiotics may be a more effective approach. The combinations may overcome resistance and repurpose antibiotics that would otherwise be ineffective against resistant bacterial strains. In this study, Terminalia sericea leaves were extracted with solvents of varying polarity and the resultant extracts were investigated for the ability to inhibit bacterial growth using disc diffusion and liquid dilution MIC techniques. The effects of combinations of the extracts and conventional antibiotics (chloramphenicol, ciprofloxacin, erythromycin, gentamycin, penicillin-G or tetracyclin) were also tested using the checkerboard method. Combinations that exhibited synergistic interactions were further examined using isobologram analysis to determine the ideal ratios of extract-antibiotic. Toxicity was evaluated using Artemia nauplii and human dermal fibroblast (HDF) toxicity assays. The methanolic and water T. sericea extracts were good inhibitors of the microbial triggers of several autoimmune diseases, with MIC values substantially <1000 µg/mL against all bacteria tested except P. aeurginosa. The extracts were particularly potent inhibitors of Proteus spp., with MICs as low as 180 µg/mL. However, combinations of T. sericea extracts and conventional antibiotics were substantially more effective in inhibiting the growth of some bacterial species. In total, four combinations were synergistic and a further eight combinations had additive effects. Although the mechanisms of potentiation are still unclear, compounds within T. sericea extracts 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 beneficial for drug design against the bacterial triggers of rheumatoid arthritis, ankylosing spondylitis, multiple sclerosis and rheumatic fever. All extracts, antibiotics and combinations were nontoxic in the Artemia nauplii and HDF toxicity assays, further indicating their potential for medicinal use. • Polar T. sericea extracts were strong inhibitors of bacterial growth when tested alone. • Some plant extract-antibiotic combinations were substantially more effective antibacterial agents. • Some weak antibiotics were substatially potentiated in combination with the extracts. • T. sericea extracts were nontoxic in A. nauplii and HDF assays. [ABSTRACT FROM AUTHOR]

Increasing bacterial resistance and a corresponding decrease in antibiotic discovery has made the development of new antibiotic therapies a high priority. Combinational approaches may be effective in overcoming resistance and potentiating the activity of conventional antibiotics that are otherwise ineffective against resistant bacteria. Moringa oleifera leaf, fruit pulp and seeds were extracted and investigated for the ability to inhibit bacterial growth using disc diffusion and liquid dilution MIC techniques. The extracts were also combined with conventional antibiotics and tested against the microbial triggers of some autoimmune diseases. Whilst some M. oleifera extracts were effective bacterial growth inhibitors, the majority had only low to moderate activity. The seed ethyl acetate and chloroform extracts were particularly noteworthy against Klebsiella pneumoniae (MICs of 976 and 402 μg/mL respectively) and against Proteus vulgaris (MICs of 500 and 938 μg/mL respectively). However, combinations of the M. oleifera extracts with conventional antibiotics proved substantially more effective. In total, 27 combinations were synergistic (18 against P. vulgaris , 1 against K. pneumoniae , 5 against Acinetobacter baylyi and 3 against Pseudomonas aeruginosa). Notably, several antibiotics with low inhibitory activity alone were returned to a state of substantial activity when tested in combination with the extracts. Moringa oleifera extracts may function as resistance modifying agents, potentiating the activity of several antibiotics that are relatively ineffective alone. Identification of these agents may be highly beneficial in drug design against several bacteria. • Moringa oleifera extracts were weak inhibitors of bacterial growth when tested alone. • Extract–antibiotic combinations were substantially more effective antibacterial agents. • Some weak antibiotics were substatially potentiated in combination with the extracts. • The M. oleifera extracts were nontoxic in A. nauplii and HDF assays. [ABSTRACT FROM AUTHOR]