Browsing by Author "Weitz, Frans M."

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    Assessing the vegetation and soil microbial ecology of renosterveld rangelands around Nieuwoudtville, Northern Cape Province
    (University of the Western Cape, 2015) Solomon, Gabrielle Marie; Weitz, Frans M.; Cupido, C. F.; Swart, W. J.
    The Bokkeveld Plateau, a region hosting high plant endemism, is home to two arid mountain centre renosterveld types. One, Nieuwoudtville Shale Renosterveld, has partially been transformed into croplands and pastures, with about 40 % remaining as non-contiguous fragments on privately owned land, and is used as natural rangelands for sheep grazing. The vegetation, soil chemical parameters, and rhizosphere soil microbial ecology of a dominant plant, Eriocephalus purpureus, were assessed. A combination of field sampling and recording, laboratory analyses of soil samples, and interviews were used to glean data. Data were statistically analysed using multivariate techniques. Overall plant species richness did not differ among the study sites, though plant species richness and cover of the different plant growth form categories varied among the sites. Soil chemical parameters varied among sites. Soil chemical and rhizosphere soil microbial parameters co-varied, and showed different profiles among the study sites. High cover of E. purpureus was associated with high microbial enzyme activity, while high cover of (other, non-dominant) non-succulent shrubs was associated with high bacterial functional diversity. Cover of geophytes, Asparagus capensis and perennial grass was associated with high microbial biomass. The findings indicate that E. purpureus-dominated Niewoudtville Shale Renosterveld is heterogeneous not only in terms of vegetation, but also in terms of soil chemical and microbial parameters. The results support the conservation of all fragments of remaining renosterveld, as they may serve as valuable resources of not only plant genetic material but also of soil microbial communities.
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    The effects of Elytropappus rhinocerotis Cass and Pelargonium triste (L.) L'Hèrit on animal health and metabolism
    (University of the Western Cape, 2003) Duarte, Nazeema; Johnson, Quinton; Weitz, Frans M.
    Many South Africans use cultural traditions and practices in the management of their health. Elytropappus rhinocerotis is an important medicinal plant, which is widely distributed in regions of South Africa. The objective of this study was to evaluate the anti-microbial characteristics of Elytropappus rhinocerotis extracts and to assess its effects on animal and metabolism. Elemental analyses were done on the plant and soil samples to determine the concentrations of selected elements within the plant. The leaves were sectioned using freeze-microtomy. Elytropappus rhinocerotic was screened using a MeOH extract and the disc diffusion method against Staphylococcus aureus (ATCC2gzl3), Mycobacterium smegmatis, Pseudomonas aeruginosa (ATCC27853) and dandida albicans (ATCC1023I). The positive control for the bacteria was Ciprofloxacin and Amphotericin B for the fungal yeast. Elytropappus rhinocerotic aqueous extract was administered to female mice (NMRI strain), which were divided into two groups of 10 each. The mice were given lgllO0mykddz1 of the plant extract for a period of 6 weeks. Various metabolic parameters were assessed over time and included the mice mass, stool production and selected elemental analyses, and water and food consumption. A variety of blood parameters and selected tissue samples were analysed after the animals were sacrificed. There was no significant difference between the plant and soil analyses. The trichomes are anti-herbivory or iridescent techniques of the plant. The sclereids around the vascular bundle are part of the desiccation prevention methods of the plant. The plant extracts had no effect on the microbial pathogens. Furthermore, there were no significant differences in metabolic parameters between the plant medicine and placebo group, except for the following: The mass of the Elytropappus rhinocerotic group was significantly higher (PS 0.05) at week two when compared to the placebo controls. On the other hand, the Elytropappus rhinocerotis group excreted less (P< 0.05) Cu at week 4 compared with the control group. The haematology indicated that the Elytropappus rhinocerotis group had elevated immune surveillance in that these animals had significantly higher (PS 0.05) levels of white blood cells, Neutrophils and Lymphocytes. The red blood cell parameters remained largely unaffected, except for mean cell haemoglobin concentration, which was higher (PS 0.05), and the mean cell volume, which was lower (P< 0.05) in the Elytropappus rhinocerotis group compared to the placebo. Moreover, there were no differences between the tissue architecture of both groups. This investigation has shown that Elytropappus rhinocerotic had no direct effect on microbial growth but significantly improved immune cell numbers, with minimal physiologically important effects on red blood cell parameters. These outcomes compel us to further study Elytropappus rhinocerotic as a potential anti-infective indigenous phytotherapy that may exert its effects via immune enhancement, especially when we consider its favorable safety profile.