Choene, Mpho Susan2013-02-012013-02-012013-02-01http://hdl.handle.net/10539/12362In this research we aimed to investigate the anti-proliferative properties of three South African plants: Kedrostis foetidissima, Euphorbia mauritanica and Elytropappus rhinocerotis against breast cancer cells. This was done on the basis of their documented ethno-medicinal use against cancer and other ailments. The plant extracts were screened for cytotoxicity and pro-apoptotic activity against two breast cancer cell lines MCF-7 and YMB-1. With an IC50 ~ 100 μg/ml, K. foetidissima was the only extract that exhibited significant cytotoxicity on both cell lines, whilst E. mauritanica was cytotoxic to MCF-7 cells only. The cytotoxicity assay was followed by the Annexin-V detection assay to evaluate the occurrence of apoptosis. The results observed suggested that K. foetidissima was inducing significant apoptosis on both YMB-1 and MCF-7 cells, whilst E. mauritanica was inducing significant apoptosis on MCF-7 cells. Since both K. foetidissima and E. mauritanica crude extracts induced apoptosis to MCF-7 cells, they were selected for gene expression studies on MCF-7 using real-time PCR. This was done with the aim of investigating if these extracts were having an effect on the tumour suppressors p53 and RBBP6, which were shown in previous studies to be deregulated in up to 50% of cancers. From the real-time PCR data we observed no changes in the expression levels of these genes following treatment with the herbal extracts. This may suggest that these plants have an effect on other components of the apoptotic pathway other than the tumour suppressors p53 and RBBP6. The antiproliferative activity observed whilst treating these particular cell lines with K. foetidissima and E. mauritanica suggests that these South African herbal plants present themselves as potential future cancer therapeutic agents; however, further studies on these herbal plants need to be performed to validate these results. KEYWORDS: Apoptosis Breast cancer Euphorbia mauritanica Kedrostis foetidissima p53enHerbs - Therapeutic use - South Africa.Breast - Cancer - Treatment.Thesis