Browsing by Author "Cupido, Christopher N."

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    Inhibition of bacteria associated with wound infection by biocompatible green synthesized gold nanoparticles from South African plant extracts
    (MDPI, 2017) Elbagory, Abdulrahman M.; Meyer, Mervin; Cupido, Christopher N.; Hussein, Ahmed A.
    Unlike conventional physical and chemical methods, the biogenic synthesis of gold nanoparticles (GNPs) is considered a green and non-toxic approach to produce biocompatible GNPs that can be utilized in various biomedical applications. This can be achieved by using plant-derived phytochemicals to reduce gold salt into GNPs. Several green synthesized GNPs have been shown to have antibacterial effects, which can be applied in wound dressings to prevent wound infections. Therefore, the aim of this study is to synthesize biogenic GNPs from the South African Galenia africana and Hypoxis hemerocallidea plants extracts and evaluate their antibacterial activity, using the Alamar blue assay, against bacterial strains that are known to cause wound infections. Additionally, we investigated the toxicity of the biogenic GNPs to non-cancerous human fibroblast cells (KMST-6) using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. In this paper, spherical GNPs, with particle sizes ranging from 9 to 27 nm, were synthesized and fully characterized. The GNPs from H. hemerocallidea exhibited antibacterial activity against all the tested bacterial strains, whereas GNPs produced from G. africana only exhibited antibacterial activity against Pseudomonas aeruginosa. The GNPs did not show any significant toxicity towards KMST-6 cells, which may suggest that these nanoparticles can be safely applied in wound dressings.
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    Phylogeny of Southern African and Australasian Wahlenbergioids (Campanulaceae) based on ITS and trnL-F sequence data: implications for a reclassification
    (Aspt American Society of Plant Taxonomists, 2013) Cupido, Christopher N.; Prebble, Jessica M.; Eddie, William M. M.
    The Campanulaceae: Wahlenbergioideae currently comprises 15 genera, one of which, Wahlenbergia, is widespread over the southern continents. Southern Africa is the region with maximum wahlenbergioid diversity with 12 genera and approximately 252 species. A second center is Australasia with 38 Wahlenbergia species. This study used a broad sample of wahlenbergioid diversity from South Africa, Australia, and New Zealand to reconstruct a phylogeny based on chloroplast trnL-F and nuclear ITS sequences. Data were analyzed separately and in combination using parsimony and Bayesian methods. The results suggest that for the wahlenbergioids to be monophyletic Wahlenbergia hederacea has to be excluded and that none of the South African, Australian or New Zealand lineages are strictly monophyletic. There are five species assemblages that are in some disagreement with current classification in the family. Wahlenbergia, Prismatocarpus and Roella are shown to be non-monophyletic and implications for a reclassification are presented. Careful consideration of morphological characters is suggested before the adjustment of generic circumscriptions can be accomplished.