Submitted in complete fulfillment of the requirements for the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2012. / Immunomodulation using plants is of primary interest in scientific communities because it provides an alternative to conventional chemotherapy for a wide range of diseases. It is based on the ability of the plants to effectively modulate immune functions, thus being able to promote positive health and maintain the body’s resistance to infection. This research is aimed to evaluate the immunomodulatory potential of fourteen traditional leafy vegetables from Kwa-Zulu Natal, South Africa on human peripheral blood mononuclear cells (PBMC). In this study the methanolic and aqueous extracts were screened for lymphocyte proliferation using the MTT assay. The cytokine response was evaluated by measuring the secretion of interleukin 10 (IL-10) and interferon-gamma (IFN-γ) using the ELISA assay. The subpopulation of T cells viz., CD4+, CD8+, NK and B cells were measured by flow cytometry. Most of the methanolic extracts stimulated PBMC’s whilst a few suppressed lymphocyte proliferation. Most of the aqueous extracts were inactive. The methanolic extracts of Amaranthus hybridus and Centella asiatica stimulated PBMC’s and showed an increase in IFN-γ secretion and the CD8+ cytotoxic T cells and B cells. Thus, they induced the Tc-1 immune response and stimulated cell mediated immunity. The methanolic extracts of Asystasia gangetica, Bidens pilosa, Emex australis, Justicia flava Momordica balsamina, Oxygonum sinuatum, Senna occidentalis and Sonchus oleraceous and the aqueous extracts of Amaranthus spinosus and Asystasia gangetica, Ceratotheca triloba, Oxygonum sinuatum, Physalis viscosa and Sonchus oleaceous stimulated PBMC’s and showed an increase in IL-10 secretion and the CD8+ cytotoxic T cells and B cells. Thus, they induced the Tc-2 immune response and stimulated humoral immunity. Also, the methanolic extracts of Amaranthus spinosus and Ceratotheca triloba and the aqueous extracts of Bidens pilosa and Justicia flava increased both IL-10 and IFN-γ secretion and the CD8+ vii cytotoxic T cells indicating the stimulation of both the Tc1 and Tc2 cytokine profiles. The elevated secretion of IFN-γ and IL-10 caused by the extracts can be attributed to the CD8+ cytotoxic T cells and B cells. The findings of this study show that leafy vegetables hold promise as immunomodulatory candidates. They may enhance cell-mediated immune functions by a pro-inflammatory response whilst some can promote humoral immune functions by means of an anti-inflammatory response. Further investigation should be considered on the effect of the extracts on other immune parameters. / National Research Foundation

Food insecurity remains a major challenge affecting the rural poor households in South Africa. The consumption of green leafy vegetables is important to address micronutrients deficiency in rural communities and, at the same time, it contributes to fibre intake. This study investigated the people’s attitude towards the cultivation and utilisation of ILVs in rural communities. A cross-section survey study was conducted among 1 000 respondents in randomly selected households in communities. The majority of respondents were not willingly consuming ILVs. This is because most consumers were black and of the low-income group. ILVs that are consumed grow mainly in the wild. The regular consumption of these vegetables as indicated in this study is interesting, as this will help in mitigating micronutrient deficiency. Furthermore, these vegetables could be incorporated in formulated food to improve iron and zinc, especially in infant foods formulation. Based on the findings of this study it would be important to find ways of encouraging cultivation of ILVs for both nutrition and as income generating activities. / Life and Consumer Science / M.CS.

Submitted in partial fulfilment for the Degree of Master of Technology: Food Technology, Durban Institute of Technology, 2003. / Leafy vegetables provide valuable nutrients to humans. Indigenous or traditional vegetables are rapidly being replaced by exotic plants. These vegetables are often costly and not easily available to communities. This study was undertaken to determine the nutritional composition of the leaves of twenty traditional leafy vegetables namely Solanum nigrum, Physalis viscosa, Cucumis metuliferus, Momordica balsamina, Amaranthus spinosus, Amaranthus hybridus, Amaranthus dubius, Asystasia gangetica, Justicia flava, Emex australis, Oxygonum sinuatum, Bidens pilosa, Cleome monophylla, Portulaca oleracea, Wahlenbergia undulata, Senna occidentalis, Chenopodium album, Ceratotheca triloba, Galinsoga parviflora and Centella asiatica from different locations in Kwa-Zulu Natal. The leafy vegetables were analysed for protein, moisture, fat, fibre, carbohydrates, ash, energy values and nutritionally valuable mineral elements (Ca, P, Na, Zn, Mg, Mn and Fe). / M

A high rate of micronutrient deficiencies persists in Africa with the most vulnerable groups being women and children. The Moringa oleifera tree has been identified to help alleviate malnutrition at household level because of its rich content of vitamin A in its plant form - beta-carotene, iron and vitamin C. The objectives of this study was to identify households that consumed Moringa, to identify households that required diet diversification through the use of a Household Dietary Diversity Score (HDDS) and to determine the acceptability of various dishes prepared from Moringa leaves as a possible contribution to the alleviation of malnutrition in resource poor communities. The dietary diversity score of the traditional Bapedi community is 4.7 and the results of the acceptability test of dishes prepared with Moringa indicated that Moringa could be recommended as an additional food ingredient to add micronutrient to the diet of Bapedi communities. / Agriculture and Environmental Sciences / M.A. (Human Ecology)

A high rate of micronutrient deficiencies persists in Africa with the most vulnerable groups being women and children. The Moringa oleifera tree has been identified to help alleviate malnutrition at household level because of its rich content of vitamin A in its plant form - beta-carotene, iron and vitamin C. The objectives of this study was to identify households that consumed Moringa, to identify households that required diet diversification through the use of a Household Dietary Diversity Score (HDDS) and to determine the acceptability of various dishes prepared from Moringa leaves as a possible contribution to the alleviation of malnutrition in resource poor communities. The dietary diversity score of the traditional Bapedi community is 4.7 and the results of the acceptability test of dishes prepared with Moringa indicated that Moringa could be recommended as an additional food ingredient to add micronutrient to the diet of Bapedi communities. / Agriculture and Environmental Sciences / M.A. (Human Ecology)