The medicinal plant Sutherlandia frutescens (SF) is commonly consumed in South Africa,
and is traditionally applied to a range of ailments. Yet its popularity stems from the use of SF
as a cancer treatment. This plant contains a range of active compounds including L-canavanine
(L-CAV), D-pinitol and gamma (γ)-aminobutyric acid, all of which contribute to
the therapeutic properties of SF. It is also endorsed by the South African Ministry of Health
as a supplementary treatment for HIV/AIDS.
Maize is the staple crop of South Africa, and can be frequently contaminated by the
mycotoxin fumonisin B1 (FB1). The mycotoxin is linked to an extensive list of livestock
diseases. Although little is known about its role in human disease, FB1 has been
epidemiologically linked to oesophageal cancer in South Africa.
Both SF and FB1 have been shown to promote apoptosis, and the effect(s) of consuming both
in combination is currently unknown.
The principle aim of this study was to determine whether SF and FB1 had either synergistic or
antagonising effects in combination, by investigating immune cell toxicity Jurkat cells.
Apoptotic parameters such as caspase activation, mitochondrial depolarisation,
phosphatidylserine (PS) externalisation and ATP quantification were analysed. Levels of
caspase activation were highest in cells treated with SF only (caspase-3: 86.79 RLU, no
significance compared to other treatments; caspase-8: 40.1 RLU, significance compared to
other treatments [p<0.05]; caspase-9: 11.07 RLU, significance compared to FB1 and control
treatments [p<0.05]). ATP levels were significantly highest in SF-treated cells compared to
other treatments (8.17 RLU, [p<0.05]). Mitochondrial depolarisation was also highest in SF-treated
Jurkat cells at 18.5% depolarisation with no significance compared to other
treatments, however PS externalisation were significantly lower in SF-treated cells compared
with other treatments (3.69% [p<0.05]).
Oxidative stress parameters were also investigated, including thiobutyric acid reactive species
(TBARS), Glutathione (GSH) and Reactive Nitrogen Species (RNS) assays. TBARS levels
were significantly higher in FB1 treated cells (OD 1.95, [p<0.05]) compared to SF and
control. Glutathione and RNS levels were also lowest in FB1-treated cells.
The data suggests that SF induces apoptosis, characteristic of its nature as an anti-cancer
treatment, and FB1 induces oxidative stress, which is characteristic of its carcinogenic
properties. Based on this preliminary study, it appears that FB1 and SF both synergises and
antagonises the other in combination, yet further investigation is needed into its effects in
vivo. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/5625 |
| Date | January 2011 |
| Creators | Audain, Keiron A. |
| Contributors | Chuturgoon, Anil A. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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