213 research outputs found

    IN VITRO ANTHELMINTIC EFFECT OF ANOGEISSUS LEIOCARPUS (DC.) GUILL. & PERR. LEAF EXTRACTS AND FRACTIONS ON DEVELOPMENTAL STAGES OF HAEMONCHUS CONTORTUS

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    The anthelmintic effect of acetone leaf extract and fractions of Anogeissus leiocarpus was investigated to determine the relative efficacy of the components as anthelmintic against Haemonchus contortus (Rudolphi). The fractions were obtained by solvent-solvent group separation of the leaf extract. The fractions were evaluated for ovicidal and larvicidal activity by egg hatch inhibition assay and larval development viability assay. Best-fit LC50 values for egg hatch test were 0.360, 0.316, 0.093, 0.219 and 0.196 mg/ml for the crude acetone extract, hexane, chloroform, butanol, and 35% water in methanol fractions, respectively. While the best-fit LC50 values for larval development and viability test were 0.509, 0.162, 0.186, 0.288 and 0.130 mg/ml for the crude acetone extract, hexane, chloroform, butanol, and 35% water in methanol fractions, respectively. The 35% water in methanol fractions was the more active on larvae, although differences in activity between fractions were not significant (p>0.05). A. leiocarpus leaf extracts could find application in anthelmintic therapy in veterinary practice

    The potential role of GLUT4 transporters and insulin receptors in the hypoglycaemic activity of Ficus lutea acetone leaf extract

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    BACKGROUND: Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain. The aim was to investigate the hypoglycaemic potential of ten Ficus species focussing on glucose uptake, insulin secretion and the possible mechanism of hypoglycaemic activity. METHODS: The dried and ground leaves of ten Ficus species were extracted with acetone. The dried acetone extract was reconstituted with DMSO to a concentration of 100 mg/ml which was then serially diluted and used to assay for glucose uptake in muscle, fat and liver cells, and insulin secretion in pancreatic cells. RESULTS: Only the F. lutea extract was able to modulate glucose metabolism. In comparison to insulin in the primary muscle cells, the glucose uptake ability of the extract was 33% as effective. In the hepatoma cell line, the extract was as effective as metformin in decreasing extracellular glucose concentration by approximately 20%. In the pancreatic insulin secretory assay, the extract was 4 times greater in its secretory activity than commercial glibenclamide. With F. lutea extract significantly increasing glucose uptake in the primary muscle cells, primary fat cells, C2C12 muscle and H-4-II-E liver cells, the extract may act by increasing the activity of cell surface glucose transporters. When the 3T3-L1 pre-adipocytes were compared to the primary muscle, primary fat and C2C12 cells, the differences in the former’s ability to transport glucose into the cell may be due to the absence of the GLUT4 transporter, which on activation via the insulin receptor decreases extracellular glucose concentrations. Because the pre-adipocytes failed to show any active increase in glucose uptake, the present effect has to be linked to the absence of the GLUT4 transporter. CONCLUSION: Only F. lutea possessed substantial in vitro activity related to glucose metabolism. Based on the effect produced in the various cell types, F. lutea also appears to be a partial agonist/antagonist of the insulin cell membrane receptor. While the clinical effectiveness of F. lutea is not known, this plant species does possess the ability to modify glucose metabolism

    DETECTION OF ANTIMICROBIAL COMPOUNDS BY BIOAUTOGRAPHY OF DIFFERENT EXTRACTS OF LEAVES OF SELECTED SOUTH AFRICAN TREE SPECIES

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    The hexane, acetone, dichloromethane and methanol extracts of Combretum vendae A.E. van Wyk (Combretaceae), Commiphora harveyi (Engl.) Engl. (Burseraceae), Khaya anthotheca (Welm.) C.DC (Meliaceae), Kirkia wilmsii Engl. (Kirkiaceae), Loxostylis alata A. Spreng. ex Rchb. (Anacardiaceae), Ochna natalitia (Meisn.) Walp. (Ochnaceae) and Protorhus longifolia (Bernh. Ex C. Krauss) Engl. (Anacardiaceae) were screened for their antimicrobial activity. The test organisms included bacteria (Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus), and fungi (Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Microsporum canis and Sporothrix schenckii). A simple bioautographic procedure, involving spraying suspensions of the bacteria or fungi on thin layer chromatography (TLC) plates developed in solvents of varying polarities was used to detect the number of antibacterial and antifungal compounds present in the extracts. All the extracts had antimicrobial activity against at least one of the test microorganisms. This activity was denoted by white spots against a red-purple background on the TLC plates after spraying with tetrazolium violet. Twenty seven TLC plates; 9 for each solvent system and 3 different solvent systems per organism were tested in the bioautographic procedure. Of the bacteria tested, S. aureus was inhibited by the most compounds separated on the TLC plates from all the tested plants. Similarly, growth of the fungus C. neoformans was also inhibited by many compounds present in the extracts. Loxostylis alata appeared to be the plant extract with the highest number of inhibition bands when compared with other plants tested against both bacteria and fungi. This species was selected for in depth further study

    A SIMPLIFIED BUT EFFECTIVE METHOD FOR THE QUALITY CONTROL OF MEDICINAL PLANTS BY PLANAR CHROMATOGRAPHY

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    Three of the factors limiting the rational use of herbal medicine are uncertainty on effectivity, uncertainty on safety and variation in quality of the product. Because many herbal medicines have been used over centuries by indigenous peoples, the safety and effectivity is frequently not such a big concern. With more people collecting and distributing herbal medicine, the offered product is however, frequently not what the label indicates either through a genuine mistake, but also through fraud especially where expensive herbal medicine is concerned. Some wrong identifications have already led to serious side effects and deaths. Planar chromatography or thin layer chromatography [TLC] is widely used to verify the identity of plant extracts by determining the chemical fingerprint of the extracts. In a leading publication 17 different extractants, 41 solvent systems and 44 spray reagents have been used to verify the identity of important herbal preparations. We investigated whether a simplified system could not be developed to aid small laboratories in identifying different herbal medicines. We compared the efficacy of different extractants, identified and developed three TLC solvent systems that would separate compounds with low, medium and high polarity and then also investigated the use of several spray reagents. With acetone as extractant and benzene:ethanol:ammonia [9:1:0.1], chloroform:ethylacetate:formic acid [5:4:1] and ethylacetate:methanol:water [10:1.35:1] as TLC solvent system and vanillin-sulphuric acid as spray reagent the identity of 81 samples of more than 50 herbal preparations could be verified on the basis of the chromatograms. The same product from different suppliers usually gave similar chromatograms. More importantly in several cases it was clear that products with the same label were so different that a mistake must have occurred in the labelling. This method has found application in the quality control of the most important African medicinal plants in the recently published African Herbal Pharmacopoeia produced by the Association for African Medicinal Plant Standards (AAMPS)

    ANTIMYCOBACTERIAL, ANTIOXIDANT AND CYTOTOXIC ACTIVITIES OF ESSENTIAL OIL OF GALL OF PISTACIA ATLANTICA DESF. FROM ALGERIA

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    Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria. Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium fortuitum. Antioxidant activity was determined using free-radical scavenging assays. The safety of essential oil was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on C3A and Vero monkey kidney cells. Results: The minimal inhibitory concentration (MIC) values ranged from 0.16 to 2.5 mg/mL with minimal bactericidal concentration (MBC) values ranged from 0.62 to >2.5 mg/mL. The antioxidant activity showed IC50 values ranged between 417.61 - >2000µg/mL and 495.6 - >2000µg/mL for DPPH and ABTS assay respectively. The cytotoxicity assay showed LC50 ranged between 26.47 to 93.64 µg/mL against Vero cells and 74.29 to 225.40 µg/mL against C3A. The results of this study show that the essential oils from the gall of P. atlantica have low toxicity and moderate activity against fast growing M. smegmatis and M. aurum. Conclusion: These results substantiate their potential as used in the treatment of non-tuberculous mycobacterial infections. This finding is predictive of their activity against M. tuberculosis, therefore, further study might be considered to investigate the activity against pathogenic Mycobacterium strains

    Novel Mycobacterium avium species isolated from Black Wildebeest (Connochaetes gnou) in 5 South Africa

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    A study was undertaken to isolate and characterize Mycobacterium species from black wildebeest suspected of being infected with tuberculosis in South Africa. This led to the discovery of a new Mycobacterium avium species, provisionally referred to as the Gnou isolate from black wildebeest (Connochaetus gnou). Sixteen samples from nine black wildebeest were processed for Mycobacterium isolation. Following decontamination; samples were incubated in an ordinary incubator at 37°C on Löwenstein-Jensen slants and in liquid medium tubes using the BACTECTM MGITTM 960 system respectively. Identification of the isolate was done by standard biochemical tests and using the line probe assay from the GenoType® CM/AS kit (Hain Life Science GmbH, Nehren, Germany). The DNA extract was also analyzed using gene sequencing. Partial gene sequencing and analysis of 16S rRNA gene, 16S-23S rRNA (ITS), rpoB and hsp65 and phylogenetic analyses by searching GenBank using the BLAST algorithm were conducted. Phylogenetic trees were constructed using four methods, namely Bayesian inference, maximum likelihood, maximum parsimony and neighbor-joining methods. The isolate was identified as Mycobacterium intracellulare using the GenoType® CM/AS kit and as Mycobacterium avium complex (MAC) by gene sequencing. The gene sequence targeting all the genes, ITS, 16S rRNA, rpoB and hsp65 and phylogenetic analyses indicated that this isolate presented a nucleotide sequence different from all currently published sequences, and its position was far enough from other MAC species to suggest that it might be a new species.NRF; Bilateral research collaboration between South Africa and the Japan Society for the Promotion of Science (JSPS); UnisaAgriculture and  Animal Healt

    Evaluation of the antibacterial and anticancer activities of some South African medicinal plants

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    <p>Abstract</p> <p>Background</p> <p>Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.</p> <p>Methods</p> <p>This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of <it>Escherichia coli </it>by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).</p> <p>Results</p> <p>The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mℓ to 2.5 mg/mℓ after 24 h of incubation. <it>Eucomis autumnalis </it>and <it>Cyathula uncinulata </it>had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of <it>E. autumnalis </it>had the strongest cytotoxicity with IC<sub>50 </sub>of 7.8 μg/mℓ. Ethyl acetate and butanol fractions of <it>C. uncinulata, Hypoxis latifolia, E. autumnalis </it>and <it>Lantana camara </it>had lower cytotoxic effects on the cancer cell lines tested with IC<sub>50 </sub>values ranging from 24.8 to 44.1 μg/mℓ; while all the fractions of <it>Aloe arborescens </it>and <it>A. striatula </it>had insignificant or no cytotoxic effects after 72 h of treatment.</p> <p>Conclusions</p> <p>Our results indicate that the methanol fraction of <it>E. autumnalis </it>had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of <it>A. arborescens </it>and <it>A. striatula </it>validates their continuous usage in ethnomedicine.</p

    Mobilising Knowledge through Global Partnerships to Support Research-informed Teaching: Five Models for Translational Research

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    Education Futures Collaboration Charity The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Improving the quality of teaching is of global concern: UNESCO’s Sustainable Development Goal (SDG) 4c in the Education 2030: Framework for Action calls for high quality teaching for all. The OECD challenges the education system to improve Knowledge Management. JET’s (2015) special issue: Translational Research (TR) and Knowledge Mobilisation in Teacher Education introduced the concept of ‘translational’ or ‘theory to practice’ research - well-established in medicine but not in education. Five TR models were subsequently developed by the MESH charity’s international network with organisations in South Africa, Bangladesh, Australia, Pakistan, UK. These distinct models engage 1) university staff and teachers 2) subject associations, 3) research units, 4) an international NGO working in crisis settings, 5) PhD tutors and students. Each model shares common features forming the MESH Translational Research methodology introduced in this article. A TR repository is part of the MESH knowledge mobilisation strategy giving teachers access to research summaries which, overtime, accumulate knowledge. TR publications called MESHGuides (www.meshguides.org) complement existing forms of publication. This article proposes the MESH TR methodology as one affordable and scalable solution to OECD and UNESCO’s challenges of keeping teachers up-to-date and making new knowledge accessible to teachers regardless of location
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