Improved lung function and body mass index associated with long-term use of Macrolide antibiotics

AbstractBackground: A number of studies have suggested that the non-antimicrobial actions of macrolide antibiotics may be valuable in treating patients with cystic fibrosis. The use of long-term macrolide antibiotics for the management of CF patients colonised by Pseudomonas aeruginosa and progressive pulmonary disease was introduced into our clinic in 1997. A retrospective study was undertaken to assess of the impact of this therapy. Methods: Twenty patients with progressive pulmonary disease (>10% fall in FEV1 over 12 months despite optimising conventional therapy) were commenced on Azithromycin, 250 mg daily during a 21-month period. At the time of assessment they had remained on therapy for a mean of 0.9 years. Changes in lung function, weight, body mass index (BMI) and frequency of pulmonary exacerbations were assessed. A group of 20 patients with stable lung function and matched as far as possible for age and sex was identified for comparison. Results: Pulmonary function increased significantly in the Azithromycin group with FEV1% predicted increasing from a mean of 50.2–59.1% (P=0.001) while FVC% predicted increase from 64.5 to 76.1% (P=0.002). There was small but non-significant fall in lung function in the comparison group. Body mass index increased by a mean of 1.1 in the Azithromycin group but remained unchanged in the comparison group. The number of pulmonary exacerbations requiring intravenous antibiotics declined by 48.3% in macrolide treated subjects compared to the pre-treatment period (P<0.025); frequency of exacerbations in the control group was unchanged. Conclusion: Long-term Azithromycin treatment in patients with progressive deterioration in lung function appears to have led to an improvement in pulmonary function, increased body mass index and decreased the frequency of pulmonary exacerbations requiring intravenous antibiotics

In vitro antibacterial, antioxidant and cytotoxic activity of acetone leaf extracts of nine under-investigated Fabaceae tree species leads to potentially useful extracts in animal health and productivity

BACKGROUND: The Fabaceae family is the second largest family of medicinal plants, containing more than 490 species which are being used as traditional medicine. The aim of this study was to determine the antioxidant and antibacterial activity as well as the cytotoxicity of acetone leaf extracts of nine tree species from the Fabaceae family that have not been investigated well previously for possible use in animal health and production. METHODS: The antibacterial activity was determined by a serial microdilution method against three Gram-positive and three Gram-negative bacteria. Antioxidant activity was determined using free-radical scavenging assays. The safety of the extracts was ascertained using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on Vero African green monkey kidney cells. RESULTS: Six of the nine acetone extracts had significant antibacterial activity against at least one of the six bacterial species with (MIC 20–80 μg/mL). The Crotalaria capensis extract had the highest activity against Salmonella typhimurium, followed by Indigofera cylindrica with MICs of 20 μg/mL and 40 μg/mL respectively. The Dalbergia nitidula extract had free radical scavenging capacity (IC50 of 9.31 ± 2.14 μg/mL) close to that of the positive control Trolox in the DPPH assay. The Xylia torreana extract also had high activity (IC50 of 14.56 ± 3.96 μg/mL) in the ABTS assay. There was a good correlation between antioxidant activity and total phenolic content (R2 values > 0.8). The extracts had weak or no toxicity to Vero cells, compared to the positive control doxorubicin with the LC50 varying from 10.70 ± 3.47 to 131.98 ± 24.87 μg/mL at the concentrations tested. CONCLUSION: Extracts of D. nitidula, X. torreana, C. capensis and I. cylindrica had a low cytotoxicity and high antimicrobial and/or antioxidant activity. These species are therefore promising candidates for the development of useful antimicrobial/antioxidant preparations with a low cytotoxicity that may be useful in promoting animal health and productivity.The University of Pretoria provided a postdoctoral fellowship to JPD. The National Research Foundation (NRF) and Medical Research Council (MRC) provided funding to support this study.http://www.biomedcentral.com/1472-6882/14/147am201

The 15-lipoxygenase inhibitory, antioxidant, antimycobacterial activity and cytotoxicity of fourteen ethnomedicinally used African spices and culinary herbs

ETHNOPHARMACOLOGICAL RELEVANCE : Culinary herbs and spices are widely used ethnomedically across Africa. They are traditionally employed in the treatment of several ailments including inflammation disorders, pain alleviation and infectious diseases. Pharmacological studies are necessary to provide a scientific basis to substantiate their traditional use and safety. In this study, the 15-lipoxygenase inhibitory, antioxidant, antimycobacterial and the cytotoxic activities, total phenolic and flavonoid contents of fourteen edible plants were investigated. MATERIALS AND METHODS : The 15-lipoxygenase inhibitory activity was evaluated by the ferrous oxidation-xylenol orange (FOX) assay method. The antioxidant activity was determined using free-radical scavenging assays. The antimycobacterial activity was determined by a broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium fortuitum using tetrazolium violet as growth indicator. The cytotoxicity was assessed by the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay on Vero monkey kidney cells. RESULTS : All the extracts tested had some 15-lipoxygenase inhibitory activity ranging from 32.9-78.64%. Adansonia digitata (fruit) had the highest antioxidant capacity (IC50 values of 8.15 μg/mL and 9.16 μg/mL in the DPPH and ABTS assays respectively; TEAC of 0.75 in the FRAP assay) along with the highest amount of total phenolics (237.68 mg GAE/g) and total flavonoids (16.14 mg QE/g). There were good correlations between DPPH and ABTS values (R2 0.98) and between total phenolics and total flavonoids (R2 0.94). Tamarindus indica had significant antimycobacterial activity against M. aurum (MIC 78 μg/mL). As could be expected with edible plants, all the extracts had a relatively low cytotoxicity with LC50 values higher than 102 μg/mL with the exception of the two Aframomum species (33 and 74 μg/mL).CONCLUSIONS : This study provides scientific support for some of the the traditional uses and the pharmacological activities of the culinary herbs and spices investigated. The results suggest that increasing intake of some of these herbs may be useful in preventing or reducing the progression of lifestyle-related diseases. The diversity of the pharmacological activities of the extract from the fruit of Adansonia digitata suggested that this plant might be valuable for application in human and animal health.The University of Pretoria.The Medical Research Council and the National Research Foundation (Grant 77228) in South Africa.http://www.elsevier.com/locate/jep2015-10-31hb201

Extracts of six Rubiaceae species combined with rifampicin have good in vitro synergistic antimycobacterial activity and good anti-inflammatory and antioxidant activities

BACKGROUND : The Rubiaceae family has played a significant role in drug discovery by providing molecules with potential use as templates for the development of therapeutic drugs. This study was designed to study the in vitro synergistic effect of six Rubiaceae species in combination with a known anti-TB drug. The antioxidant and anti-inflammatory activity of these species were also evaluated to investigate additional benefits in antimycobacterial treatment. METHODS : The checkerboard method was used to determine the antimycobacterial synergistic activity of plant extracts combined with rifampicin. The antioxidant activity of extracts was determined by the 2,2-diphenyl- 1-picrylhydrazyl (DPPH) method. Anti-inflammatory activity via inhibition of nitric oxide (NO) production was performed in LPS-activated RAW 264.7 macrophages using the Griess assay. RESULTS : Combination of rifampicin with the crude extracts resulted in a 4 to 256-fold increase of activity of extracts. The crude extract of Cremaspora triflora produced the best synergistic effect with rifampicin, with a fractional inhibitory concentration (FIC) index of 0.08 against Mycobacterium aurum. Extracts of Psychotria zombamontana had the best antioxidant activity with an IC50 value of 1.77 μg/mL, lower than the IC50 of trolox and ascorbic acid (5.67 μg/mL and 4.66 μg/mL respectively). All the extracts tested inhibited nitric oxide (NO) production in a concentration dependent manner with the percentage of inhibition varying from 6.73 to 86.27 %. CONCLUSION : Some of the Rubiaceae species investigated have substantial in vitro synergistic effects with rifampicin and also good free radical scavenging ability and anti-inflammatory activity. These preliminary results warrant further study on these plants to determine if compounds isolated from these species could lead to the development of bioactive compounds that can potentiate the activity of rifampicin even against resistant mycobacteria.The University of Pretoria Institutional Research Theme for Animal and Zoonotic Diseases (IRT-AZD), National Research Foundation (NRF, Grant No 81010) and Medical Research Council (MRC) of South Africa provided funding to support this study. The National Research Foundation (NRF) provided a doctoral fellowship to AOA. The University of Pretoria provided a postdoctoral fellowship to JPD.http://www.biomedcentral.com/bmccom/plementalternmedam2017Paraclinical Science

Immunomodulatory and intracellular antimycobacterial activity of Oxyanthus speciosus investigated using human (U937) and mouse (RAW264.7) macrophage cell lines

Tuberculosis (TB), a disease caused by Mycobacterium tuberculosis, remains a significant cause of death due to challenges associated with present chemotherapy. Coinfection with HIV also greatly increases the risk of latent TB infection (LTBI) progressing to active disease due to the fact that HIV suppresses the immune system, thereby allowing infected individuals to become more susceptible to TB infection. Medicinal plants are used in many parts of southern Africa to treat TB-related symptoms including chest pain and coughing. The acetone extract of Oxyanthus speciosus was screened for its immunomodulatory effect against LPS-stimulated U937 macrophage cells using a cytometric bead array (CBA) technique. Human TH1/TH2 kits consisting of a mixture of six cytokines were used for the assay and analysed using flow cytometry. The intracellular efficacy of the O. speciosus extract against Mycobacterium-infected macrophages was investigated using RAW 264.7 mouse macrophage cell line. Mouse macrophages were infected with M. fortuitum with a multiplicity of infection at 10 mycobacteria per cell. The result obtained from this study revealed that the acetone extract of O. speciosus increased the expression of IL-2 at 0.1 mg/mL while rifampicin supressed the expression of this pro-inflammatory cytokine. At the tested concentration the crude extract of O. speciosus, inhibited the stimulation of IL-4 and IL-5 while it markedly increased the expression of IL-10. The acetone extract of O. speciosus did not show cytotoxicity to RAW 264.7 macrophages at the highest tested concentration (1 mg/ml). On day 6 post-infection, the intracellular antimycobacterial activity of the acetone crude extract of O. speciosus at 1X to 4X MIC was superior to that of rifampicin, showing more than 90% reduction in colony forming units. In conclusion, the extract of O. speciosus had a mixed Th1/Th2 effect. The bactericidal activity observed was both dose and time-dependent.Poster presented at the University of Pretoria, Faculty of Veterinary Science Faculty Day, August 25, 2016, Pretoria, South Africa.ab201

Anti-biofilm, antibacterial, and anti-quorum sensing activities of selected South African plants traditionally used to treat diarrhoea

DATA AVAILABILITY : The original data can be obtained from the corresponding author upon request.The development of resistance of microorganisms to conventional antibiotics is a major global health concern; hence, there is an increasing interest in medicinal plants as a therapeutic option. This study aimed to evaluate the antibacterial, anti-biofilm, and anti-quorum activities of crude extracts prepared using various solvents of nine indigenous South African plants used locally for the treatment of diarrhoea. The minimum inhibitory concentration (MIC) was determined using the broth microdilution method and the crystal violet assay was used to test the anti-biofilm activity of the extracts against a panel of bacteria. Anti-quorum sensing activity of the extracts was assessed via inhibition of violacein production in Chromobacterium violaceum ATCC 12472. Preliminary screening of extracts against E. coli ATCC 25922 revealed that the acetone extracts had significant activity, with MIC values ranging from 0.04 to 0.63 mg/mL. Further screening against a panel of bacterial pathogens showed that the acetone extract of Bauhinia bowkeri was the most active with MIC of 0.01 mg/mL against Salmonella enteritidis, followed by Searsia lancea with MIC of 0.03 mg/mL against Bacillus cereus. All the plant extracts prevented the attachment of biofilms by more than 50% against at least one of the tested bacteria. However, only the mature biofilm of B. cereus was susceptible to the extracts, with 98.22% eradication by Searsia pendulina extract. The minimum quorum sensing inhibitory concentration of the extracts ranged from 0.08 to 0.32 mg/mL with S. lancea having the most significant activity. The extract of S. lancea had the best violacein production inhibitory activity with IC50 value of 0.17 mg/mL. Overall, the results obtained indicate that acetone extracts of S. leptodictya, S. lancea, S. batophylla, S. pendulina, B. galpinii, and B. bowkeri possess antibacterial and anti-biofilm activities and can modulate quorum sensing through the inhibition of violacein production. Therefore, these results signify the potential of the selected plant extracts in treating diarrhoea through inhibition of bacterial growth, biofilm formation inhibition, and quorum sensing antagonism, supporting their medicinal use.The World Academy of Science (NRFTWAS), South Africa, the University of Pretoria, the DAAD and the National Research Foundation (South Africa).http://www.hindawi.com/journals/ecamam2023Paraclinical Science

The anti-arthritic, anti-inflammatory, antioxidant activity and relationships with total phenolics and total flavonoids of nine South African plants used traditionally to treat arthritis

BACKGROUND : Oxidative stress predisposes the human and animal body to diseases like cancer, diabetes, arthritis, rheumatoid arthritis, atherosclerosis and chronic inflammatory disorders. Hence, this study seeks to determine the antioxidant, anti-inflammatory and anti-arthritic activities of acetone leaf extracts of nine South African medicinal plants that have been used traditionally to treat arthritis and inflammation. METHODS : The anti-inflammatory activity of the extracts was determined by investigating inhibition of nitric oxide production in lipopolysaccharide activated RAW 264.7 macrophages as well as 15-lipoxygenase enzyme inhibition. An anti-protein denaturation assay was used to determine the anti-arthritic properties of the extracts. The antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethyl-benzthiazoline-6-sulfonic acid) (ABTS) radical scavenging assays and ferric reducing antioxidant power (FRAP). The total phenolic and total flavonoid concentration of extracts were determined by using standard methods. RESULTS : All extracts inhibited nitric oxide production in a dose-dependent manner in the LPS-stimulated RAW 264.7 macrophages. Extracts of Maesa lanceolata and Heteromorpha arborescens inhibited NO production by 99.16 % and 89.48 % at a concentration of 30 μg/ml respectively. Elaeodendron croceum and Calpurnia aurea extracts had strong activity against 15-lipoxygenase activity with IC50 values of 26.23 and 34.70 μg/ml respectively. Morus mesozygia and Heteromorpha arborescens extracts had good in vitro anti-arthritic activity with IC50 values of 11.89 and 53.78 μg/ml, the positive control diclofenac sodium had IC50 value of 32.37 μg/ml. The free radical scavenging activity of the extracts in DPPH assays ranged between 7.72 and 154.77 μg/ml. Trolox equivalent antioxidant capacity (TEAC) and FRAP values ranged from 0.06 to 1.32 and 0.06 to 0.99 respectively. CONCLUSIONS : Results from this study support the traditional use of the selected medicinal plants in the management of arthritis and other inflammatory conditions. The free radical scavenging capacity of the extracts may be related to an immune boosting potential.ILE is a PhD student in the Phytomedicine Programme. JPD (PhD) is a post-doctoral fellow in the Phytomedicine Programme. FSB (PhD) is Senior Lecturer and mentor in the Phytomedicine Programme. LJM (PhD) is an Associate Professor and the current leader of the Phytomedicine Programme. JNE (DSc) is a Professor and the founder of the Phytomedicine Programme in the Department of Paraclinical Sciences of the Faculty of Veterinary Science, University of Pretoria.The National Research Foundation of South Africa (Eloff IPPR 953991) and the University of Pretoria.http://www.biomedcentral.com/bmccom/plementalternmedam2016Paraclinical Science

Some South African Rubiaceae tree leaf extracts have antimycobacterial activity against pathogenic and non-pathogenic Mycobacterium species

Tuberculosis (TB) caused by Mycobacterium tuberculosis remains an ongoing threat to human health. Many plant species contain antimycobacterial compounds which may serve as template molecules for new anti-TB drugs. The Rubiaceae family is the largest family of trees in southern Africa and preliminary evidence revealed antimycobacterial activity in several species of the genus, motivating further studies. Leaf extracts of 15 tree species from the Rubiaceae family were screened for antimycobacterial activity against pathogenic M. tuberculosis and non-pathogenic M. smegmatis, M. aurum and M. bovis BCG using a two-fold serial microdilution assay. Cytotoxicity was determined using a tetrazolium-based colorimetric assay against C3A liver cells and Vero kidney cells. MIC values as low as 0.04 mg/mL against M. smegmatis and M. tuberculosis were recorded. Activity against M. aurum was the best predictor of activity against pathogenic M. tuberculosis (correlation coefficient = 0.9). Bioautography indicated at least 40 different antimycobacterial compounds in the extracts. Cytotoxicity of the extracts varied and Oxyanthus speciosus had the most promising selectivity index values.The University of Pretoria Institutional Research Theme for Animal and Zoonotic Diseases (IRT-AZD), National Research Foundation (NRF, Grant No 81010) and Medical Research Council (MRC).http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-15732016-07-30hb201

In vitro biological activities of Combretum molle R.Br. ex G. Don (Combretaceae) against mastitis-causing organisms

Bovine mastitis, caused mostly by Staphylococcus species, has gained global importance owing to the increasing prevalence of multi-drug resistant bacteria, which comprise a risk to food security and public health. In this study, the antibacterial, anti-biofilm and quorum quenching activities of six leaf extracts of Combretum molle R.Br. ex G. Don prepared using different solvents were assessed against clinical isolates of Staphylococcus aureus and two Staphylococcus ATCC strains (S. aureus ATCC 29213 and S. epidermidis ATCC 35984). The antioxidant and anti-inflammatory activity and cytotoxicity of the extracts was also evaluated. The antibacterial and anti-biofilm potential of the extracts was determined via serial microdilution and crystal violet and INT assays. Quorum quenching activity was ascertained via inhibition of violacein production in Chromobacterium violaceum ATCC 12472. The antioxidant activity was determined using in vitro chemical assays. The 15-lipoxygenase enzyme inhibition and the nitric oxide inhibition assays were utilized to ascertain the anti-inflammatory activity of the extracts. The tetrazolium-based colorimetric (MTT) reduction assay was used to determine the cytotoxicity of the extracts against Vero African green monkey kidney cells. The antibacterial activity of the extracts was moderate to good, with minimum inhibitory concentration (MIC) values of 0.02–0.63 mg/mL. The extracts had promising biofilm inhibition (≥50 %) against four of the test strains. The effects of the extracts on the metabolic activity of the test strains showed ≥ 50 % inhibition in most of the test strains at the different test times. All extracts had moderate to excellent quorum quenching activity at different concentrations with an inhibition ranging between 32.81- 96.32 %. The methanol and cold water extracts had the best antioxidant activity against the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals with IC50 of 7.79 and 2.34 µg/mL, respectively. The hot water extract (AQH) had the best anti-inflammatory activity in terms of 15-lipoxygenase enzyme inhibition with 85.26 % inhibition, while the methanol extract had the best nitric oxide inhibition in LPS-induced RAW 264.7 macrophages with inhibition of 96.75 % at 100 µg/mL. Selectivity index values of the extracts were as high as 50. Combretum molle, therefore, offers promising potential as a source of antibiofilm and anti-quorum sensing agents with the ability to disrupt microbial virulence factors. Additionally, the extract had good antioxidant and anti-inflammatory properties, supporting further research into its use in preventing and treating bovine mastitis.The National Research Foundation (NRF, South Africa) and the University of Pretoria provided a PhD scholarship.http://www.elsevier.com/locate/sajbhj2024Paraclinical SciencesProduction Animal StudiesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein

In vitro Antimycobacterial, Apoptosis-Inducing Potential, and Immunomodulatory Activity of Some Rubiaceae Species

Tuberculosis (TB), a disease caused by microorganisms of the Mycobacterium tuberculosis complex, infects almost one-third of the world’s population. The TB epidemic has been further exacerbated by the emergence of multi, extensively, and totally-drug-resistant (MDR, XDR, and TDRTB) strains. An effective immune response plays a crucial role in determining the establishment of TB infection. Therefore, the modulation of the immune system has been considered as a vital approach for the treatment or control of various immune-related diseases such as TB. In this study, the antimycobacterial, immunomodulatory, and apoptosis-inducing effects of six Rubiaceae species were evaluated. A twofold serial dilution method was used to determine the minimum inhibitory concentration values of the plant extracts. The effect of the extracts on the activity of 15-lipoxygenase was investigated. The levels of six different cytokines, IL-2, IL-4, IL-5, IL-10, IFN-γ, and TNF-α, were measured in LPS-activated U937 cell line while the apoptosis-inducing effect of the extracts was evaluated using an annexin V/PI assay using a flow cytometer. The results obtained revealed that all the six extracts tested had antimycobacterial activity against M. tuberculosis H37Rv, M. tuberculosis ATCC 25177, and Mycobacterium bovis ATCC 27299 strains, with MIC values ranging from 39 to 312 μg/mL. The extracts of Cremaspora triflora and Cephalanthus natalensis were the most active against M. tuberculosis (MIC = 39 μg/mL), followed by Pavetta lanceolata and Psychotria zombamontana against M. bovis (MIC = 78 μg/mL). The extracts of P. zombamontana and Psychotria capensis had remarkable IC50 values of 4.32 and 5.8 μg/mL, respectively, better than that of quercetin. The selected extracts promoted Th1/Th2 balances in an in vitro model at the tested concentration which may suggest the therapeutic value of the plant in diseases where inflammation is a significant factor such as TB. The addition of the crude extracts of C. triflora, P. capensis, and P. zombamontana at the tested concentrations to the cell culture medium induced apoptosis in a time- and dose-dependent manner. This interesting preliminary result generated from this study encourages further investigations of these extracts owing to the LOX-inhibitory effect, immunomodulatory, and apoptotic-inducing properties in addition to their antimycobacterial properties