Platelet exocytosis is essential for hemostasis and for many of its sequelae. Platelets release numerous bioactive molecules stored in their granules enabling them to exert a wide range of effects on the vascular microenvironment. Are these granule cargo released thematically in a context-specific pattern or via a stochastic, kinetically-controlled process? My work describes platelet exocytosis using a systematic examination of platelet secretion kinetics. Platelets were stimulated for increasing times with different agonists (i.e. thrombin, PAR1-agonist, PAR4-agonist, and convulxin) and micro-ELISA arrays were used to quantify the release of 28 distinct α-granule cargo molecules. Agonist potency directly correlated with the speed and extent of release. PAR4-agonist induced slower release of fewer molecules while thrombin rapidly induced the greatest release. Cargo with opposing actions (e.g. pro- and anti-angiogenic) had similar release profiles, suggesting limited thematic response to specific agonists. From the release time-course data, rate constants were calculated and used to probe for underlying patterns. Probability density function and operator variance analyses were consistent with three classes of release events, differing in their rates. The distribution of cargo into these three classes was heterogeneous suggesting that platelet secretion is a stochastic process potentially controlled by several factors such as cargo solubility, granule shape, and/or granule-plasma membrane fusion routes. Sphingosine 1 phosphate (S1P) is a bioactive lipid that is stored in platelets. S1P is essential for embryonic development, vascular integrity, and inflammation. Platelets are an abundant source of S1P due to the absence of the enzymes that degrade it. Platelets release S1P upon stimulation. My work attempts to determine how this bioactive lipid is released from platelets. Washed platelets were stimulated with agonists for defined periods of time and the supernatant and pellet fractions were separated by centrifugation. Lipids were separated by liquid phase extraction and S1P was quantified with a triple quadrapole mass spectrometer. A carrier molecule (BSA) is required to detect release of S1P. Further, there is a dose-dependent increase in total S1P with increasing BSA. S1P release shows characteristics similar to other platelet granule cargo e.g. platelet factor IV (PF4). Platelets from Unc13-d Jinx mice and VAMP8-/- mice, which are secretion-deficient (dense granule, alpha granule and lysosome), were utilized to understand the process of S1P release. S1P release was more affected in Unc13-d Jinx mice mirroring their dense granule secretion defect. Fluorescence microscopy and sub-cellular fractionation were used to examine localization of S1P in platelets. S1P was observed to be enriched in a granule population. These studies indicate the existence of two pools of S1P, a readily extractable agranular pool, sensitive to BSA, and a granular pool that requires the secretion machinery for release. The secretion machinery of platelets in addition to being involved in the release of normal granule cargo is thus proved to be involved in the release of bioactive lipid molecules like S1P.

Acute myocardial infarction (AMI) is the leading cause of death worldwide. Currently, the best method of treating cardiac ischemia is early reperfusion which, itself, induces myocardial damage. The mTOR complex is a key regulator of cardioprotection against cell stressors. We hypothesized that reperfusion therapy with Rapamycin, a potent mTOR inhibitor, would reduce infarct size in adult mouse hearts. Rapamycin was administered at the onset of reperfusion following 30 min in situ LAD ligation. After 24 hours of reperfusion, myocardial infarct size and apoptosis were significantly reduced in rapamycin-treated mice compared to control. Rapamycin inhibited pro-apoptotic protein Bax and phosphorylation of ribosomal protein S6 (target of mTORC1), while it induced phosphorylation of AKT (target of mTORC2). Rapamycin also induced phosphorylation of ERK, while significantly reduced phosphorylation of p38. Thus, our study shows that reperfusion therapy with Rapamycin provides cardioprotection through induction of the phosphorylation of Akt and ERK.

Phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] is a low-abundance signaling lipid important for the maintenance of the endomembrane system and selected membrane trafficking pathways. In yeast, in response to hyperosmotic stress, PI(3,5)P2 levels rise more than 20-fold in 5 minutes, and return to near basal levels in 30 minutes. This transient change suggests that PI(3,5)P2 levels are tightly regulated and may be involved in signaling a response to stress. In yeast, PI(3,5)P2 is synthesized through phosphorylation of PI(3)P by the PI(3)P 5-kinase Fab1. Loss of PI(3,5)P2 in yeast causes swollen vacuoles, defective retrograde trafficking from the vacuole, defective vacuole acidification, and mis-localization of a subset of vacuole lumenal proteins. In yeast, Vac14 is a regulator of PI(3,5)P2 levels. Mammalian Vac14 and Fab1 are found in the same complex. To study the physiological significance of PI(3,5)P2, a mouse strain was generated with the Vac14 gene disrupted by a gene-trap genomic insertion. Vac14 protein was not detectable in mutant mice. In fibroblasts cultured from the mutant mice, PI(3,5)P2 and PI(5)P are decreased to 42% and 44% of the corresponding wild-type levels, respectively. The mutant mouse brains exhibit spongiform-like morphology. Cytoplasmic vacuoles are found in neuronal cell bodies of the olfactory bulb, trigeminal ganglion, and dorsal root ganglion. Non-neural tissues appear largely normal. Similar vacuoles are also found in cultured neurons and fibroblasts. In fibroblasts, these vacuoles are formed from swelling of late endosomes/lysosomes. Some early endosomes are also enlarged. A population of cation-independent mannose-6-phosphate receptor (CI-M6PR), which recycles between endosomes and the trans-Golgi network (TGN), is trapped in early and late endosomes, indicating a block in endosome-to-TGN trafficking. These results suggest that: 1) Neurons are acutely sensitive to loss of PI(3,5)P2. 2) In mammals, PI(3,5)P2 is required for the morphology of late endosomes/lysosomes and retrograde trafficking from endosomes to the TGN. The first conclusion is supported by another mouse strain with a retro-transposon inserted in the Fig4 gene. Fig4 is another regulator of PI(3,5)P2 levels. Similar neurodegeneration was observed in the Fig4 mutant mice.

Mitochondrial dysfunction is a phenomenon observed in models of Traumatic Brain Injury (TBI). Loss of mitochondrial bioenergetics can result in diminished cellular homeostasis leading to cellular dysfunction and possible cellular death. Consequently, the resultant tissue damage can manifest as functional deficits and/or disease states. Therapeutic strategies to target this mitochondrial dysfunction have been investigated for models TBI and have shown promising effects. For this project, we tested the hypothesis that mitoNEET, a novel mitochondrial membrane protein, is a target for pioglitazone mediated neuroprotection. To test this, we used a severe Controlled Cortical Impact (CCI) injury model in mitoNEET null and wild-type mice. We then dosed these animals with pioglitazone or NL-1, which is a compound that has a similar structure to pioglitazone allowing us to hone in one the importance of mitoNEET binding. Wild-type animals treated with the mitoNEET ligands, both pioglitazone and NL-1, had improved mitochondrial function, tissue sparing and functional recovery, compared to mitoNEET null animals. In addition to this specific hypothesis tested, our experiments provided insight casting doubt on the central dogma that mitochondrial dysfunction following TBI is the result of vast oxidative damage and consequential irreversible mitochondrial loss. The data from these studies show that when mitoNEET is targeted with pioglitazone at 12 hours’ post-injury, mitochondrial dysfunction can be reversed. Additionally, when bypassing proteins upstream of Complex I with an alternative biofuel, such as beta-hydroxybuterate (BHB), TBI related mitochondrial dysfunction is once again reversed. This leads to novel hypothesis for future work which posits mitoNEET as a redox sensitive switch; when mitoNEET senses changes in redox, as seen in TBI, it inhibits mitochondrial respiration. When targeted with an agonist/ligand or bypassed with a biofuel TBI mitochondrial dysfunction can be reversed. These studies support the role of mitoNEET in the neuropathological sequelae of brain injury, supporting mitoNEET as a crucial target for pioglitazone mediated neuroprotection following TBI. Lastly, these studies propose a mechanism of TBI related mitochondrial dysfunction which can reversed with pharmacological agents.

In keeping with the goals of our laboratory, efforts in this thesis are directed towards improving our understanding, and therefore our ability to calculate, the energetics of protein-ligand interactions. Electrostatic contributions to protein-ligand binding events are poorly understood, and underrepresented in data sets used to parameterize the energetics of protein unfolding and binding. Therefore, the focus in this thesis is placed on ion-protein interactions as model systems that can give insight into the contribution of charge-charge interactions to the enthalpy, entropy, and heat capacity changes associated with binding. In order to measure the energetics of charge-charge interactions, both differential scanning calorimetry and isothermal titration calorimetry are employed. The use of linked equilibria to determine binding energetics for both extremely tight, and extremely weak binding events is described in the context of ligand binding linked to protein unfolding. The implications for drug screening methods based on protein unfolding are discussed. The theoretical development is then used to measure ion binding to proteins in two different systems that exhibit very different ion binding sites and system features. The first system involves anion binding to a protein-protein complex, in which the binding site is formed when the protein-protein complex is formed. Binding of phosphate and sulfate occur with the same energetics, indicating that net charge is not dominating the observed energetics. Further, no salt-dependence to the binding of anions is observed. In the second system ions bind to the active site of a ribonuclease. Again, phosphate and sulfate bind to the ribonuclease with the same energetics, however comparing the energetics of binding for these anions between systems reveals differences in the energetic profiles. Further, in the ribonuclease case, there is a strong salt-dependence observed for the binding of a nucleotide inhibitor. The apparent discrepancies in the observed energetics and salt-dependencies in these systems can be resolved by considering the role of desolvation upon binding as well as the binding site geometries. This analysis leads to important considerations for interpreting an observed salt-dependence to a binding event. Furthermore, it is indicated that the current structure-based energetics calculations underestimate the contributions arising from charge-charge interactions.

The global burden of heart disease increases every year. It has been estimated that by the year 2020, coronary artery disease (CAD) will be the number one cause of death worldwide. Indian populations throughout the world have the highest prevalence of CAD and early onset of the disease compared to other ethnic groups. Glutathione S-transferases (GSTs) detoxify environmental agents which influence the onset and progression of disease. Dysfunctional detoxification enzymes are responsible for prolonged exposure to reactive molecules and can contribute to endothelial damage, an underlying factor in CAD. Uncoupling proteins (UCPs) 2 and 3 play an important role in the regulation of oxidative stress which contributes to chronic inflammation. Coronary artery disease is a chronic inflammatory disorder characterized by elevated levels of C-reactive protein (CRP) and pro-inflammatory cytokines such as interleukin 6 (IL-6). Polymorphisms of these genes have been linked to CAD and other chronic diseases. Statins, metabolised in the liver, are the most commonly used drug to control atherosclerosis progression in CAD patients. The pleiotropic effects of statins have been attributed to both favourable and adverse outcomes in CAD patients particularly related to myopathy and hepatotoxicity. All patients (n=102) recruited into this study were South African Indian males. A corresponding age-, gender- and ethnicity-matched control group (n=100) was also recruited. The frequency of the GSTM1 +/0, GSTP1 A105/G105, IL6 -174G/C and CRP -390C/A/T genotypes was assessed by polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism (PCR-RFLP). For the in vitro study, the biological effect of atorvastatin on HepG2 cells was assessed. The metabolic activity, cytotoxicity, oxidative stress and nitric oxide production was assessed by the ATP, lactate dehydrogenase (LDH), thiobarbituric acid reactive substance (TBARS) and Griess assays, respectively. The profile of 84 microRNA (miRNA) species was evaluated using the miRNA Pathway Finder PCR SuperArray. The predicted targets of up-regulated miRNAs were determined using the online software, Targetscan. The mRNA levels of guanidinoacetoacetate (GAMT), arginine glycine aminotransferase (AGAT) and spermine oxidase (SMO) were determined using quantitative PCR. Western blotting was used to determine GAMT and phosphorylated p53 levels in treated cells. The GSTM1 0/0 and GSTP1 A105/A105 genotypes occurred at higher frequencies in CAD patients compared with the control group (36% vs. 18% and 65% vs. 48%, respectively). A significant association with CAD was observed in GSTM1 0/0 (odds ratio (OR)=2.593; 95% confidence interval (CI) 1.353 - 4.971; p=0.0043) and GSTP1 A105/A105 OR=0.6011; 95% CI 0.3803 - 0.9503; p=0.0377). We found a significant association between smoking and CAD; the presence of either of the respective genotypes together with smoking increased the CAD risk (GSTP1 A105 relative risk (RR)=1.382; 95% CI 0.958 - 1.994; p=0.0987 and GSTM1 null RR=1.725; 95% CI 1.044 - 2.851; p=0.0221). The UCP2 -866G/A and UCP3 -55C/C genotypes occurred at highest frequency in CAD patients (59% vs. 52% and 66% vs. controls: 63% respectively) and did not influence the risk of CAD. Homozygous UCP3 -55T/T genotype was associated with highest fasting glucose (11.87±3.7mmol/L vs. C/C:6.11±0.27mmol/L and C/T:6.48±0.57mmol/L, p=0.0025), HbA1c (10.05±2.57% vs. C/C:6.44±0.21% and C/T:6.76±0.35%, p=0.0006) and triglycerides (6.47±1.7mmol/Lvs. C/C:2.33±0.17mmol/L and C/T:2.06±0.25mmol/L, p<0.0001) in CAD patients. A significant association between the G allele of the IL6 -174 polymorphism and non-diabetic CAD patients was found (p=0.0431 odds ratio: 1.307, 95% CI: 1.047-1.632). A significant association with the C allele of the -390 CRP triallelic variants and CAD (p=0.021 odds ratio: 1.75, 95% CI: 1.109-2.778) was also found using a contingency of the C allele vs. the minor A and T allele frequencies. The strength of the association of the C allele with non- diabetic CAD subjects was much higher (p=0.0048 odds ratio: 2.634, 95% CI: 1.350-5.138). Circulating median levels of IL-6 (0.9 (0.90, 0.91) pg/ml and 0.9 (0.87, 0.92) pg/ml) and CRP (5.65 (1.9, 8.2) mg/l and 2.90 (1.93, 8.35) mg/l) were similar between CAD patients and controls, respectively. A similar finding was observed between controls and non-diabetic CAD subjects. Levels of IL-6 and CRP in CAD subjects were not significantly influenced by polymorphic variants of IL-6 and CRP. In the control group, the level of IL-6 was significantly influenced by the IL6 -174 G allele (p=0.0002) and the CRP -390 C allele (p=0.0416), where subjects with the homozygous GG (0.9 (0.9, 1,78) pg/ml) and CC (0.9 (0.9, 0.95) pg/ml) genotype had higher levels than the C allele carriers (0.9 (0.64, 0.91) pg/ml) or A and T carriers (0.9 (0.69, 0.91) pg/ml) combined. The lowest measure of proliferation/metabolism in HepG2 cells was observed at 20μM atorvastatin, with 82±9.8% viability. The level of cytotoxicity was increased in statin treated cells from 0.95±0.02 units to 1.11±0.03 units (p=0.001) and malondialdehyde levels was reduced from 0.133±0.003 units to 0.126±0.005 units (p=0.009) whilst nitrite levels were elevated (0.0312±0.003 units vs. control: 0.027±0.001 units, p=0.044). MicroRNAs most significantly upregulated by atorvastatin included miR-302a-3p (3.05-fold), miR-302c-3p (3.61-fold), miR-124-3p (3.90-fold) and miR-222-3p (4.4-fold); miR-19a-3p, miR-101-3p and let-7g were downregulated (3.63-fold, 2.92-fold, 2.81-fold, respectively). A list of miRNA targets identified included those with a role in metabolism and inflammation. The miR-124a specifically targets the mRNA of GAMT and SMO. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.

Highly active antiretroviral therapy (HAART) is currently the only treatment that effectively reduces the morbidity and mortality of individuals infected with Human Immunodeficiency Virus-1 (HIV-1). Standard HAART regimens typically comprise 2 nucleoside reverse transcriptase inhibitors and either one non-nucleoside reverse transcriptase inhibitor or a protease inhibitor. These drugs bind to and inhibit the HIV-1 Reverse Transcriptase and Protease enzymes respectively, thereby suppressing viral replication. The nucleoside reverse transcriptase inhibitors promote mitochondrial (mt) dysfunction by strongly inhibiting mt polymerase gamma (Pol-y) and subsequently, mtDNA replication. In contrast, the non-nucleoside reverse transcriptase inhibitors, efavirenz (EFV) and nevirapine (NVP) do not inhibit Pol-y although EFV has been shown to induce mt depolarisation ( mlow) in vitro at supra-therapeutic concentrations. However, the capacity of non-nucleoside reverse transcriptase inhibitor drugs to induce mt toxicity in vivo previously remained undetermined. The objective of this study was to determine the influence of EFV and NVP on peripheral lymphocyte mt transmembrane potential (Avj/m) and apoptosis in HIV-1-infected patients treated with these non-nucleoside reverse transcriptase inhibitors. Thirty-two HIV-1-infected patients on HAART between 4 and 24 months (12 on EFV, 20 on NVP) and 16 HAART-naive HIV-1-infected patients were enrolled into this study. All participants were black South African patients. Spontaneous peripheral lymphocyte apoptosis and mlow were measured ex vivo by flow cytometry for all patients. CD4 T-helper apoptosis for the EFV and NVP cohorts was 19.38% ± 2.62% and 23.35% ± 1.51% (mean ± SEM), respectively, whereas total lymphocyte mlow was 27.25% ± 5.05% and 17.04% ± 2.98%, respectively. Both parameters for each cohort were significantly lower (P < 0.05) than that of the HAART-naive patients. The NVP cohort exhibited both a significant time dependent increase in peripheral lymphocyte ö¿mlow (P = 0.038) and correlation between Thelper apoptosis and low (P = 0.0005). These trends were not observed in the EFV cohort. This study provides evidence that both EFV and NVP induce peripheral lymphocyte ö¿ m low in HIV-1-infected patients on non-nucleoside reverse transcriptase inhibitor-based HAART, which in the case of NVP is sufficient to induce the apoptosis cascade. / Thesis (M.Med.Sci.)--University of KwaZulu-Natal, 2008.

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.

The use of antibiotics and antimicrobial drugs has played a large role in the elimination of many infectious diseases, however the wide spread use of such drugs has given rise to the phenomenon of antimicrobial resistance and has rendered antibiotics ineffective to a broad range of bacteria. The aim of the study was to ascertain the differences if any in the phenotypic and genotypic resistance profiles of K. pneumoniae isolated from a single tertiary hospital in two surveillance studies undertaken at different times, viz., 2001 and 2007 with special emphasis on ESBLs. A correlation with antibiotic use was also undertaken. ESBL positives were identified and phenotypic resistance profiles were generated based on the resistance profiles of individual isolates by means of their MIC data. The molecular detection of ESBLs was carried out using representative isolates and sequencing was based on the phenotypic expression of the most common ESBL genes. The data was summarized using median values and interquartile ranges. Antibiotic use and susceptibility in 2000 was compared to that in 2007 using a Wilcoxon signed rank test for paired data since the same drugs were tested in both years. Of the isolates that were tested, sequencing revealed that TEM – 1 was identified in all isolates and SHV-1 and SHV-2 were identified in 60 % in the isolates collected in 2000 and 77 % and 11 % respectively in the isolates collected in 2007. SHV – 11 was present in 67% of isolates from 2007 and 55% of those were in combination with SHV – 1. Sequencing also revealed CTXM-15 present in one of the isolates collected in 2007. There was 100% susceptibility to cefoxitin and only one isolate in 2007 showing an intermediate result to imipenem. No novel β-lactamases were identified in this study; however the decrease in susceptibility over time is proof of bacterial evolution. The variety of β-lactamases and diversity of plasmid profiles in these two small populations provides proof to the claim that dissemination of resistance in Klebsiella pneumonia is effortless. Statistical analysis showed an increase in resistance from the year 2000 to 2007 however the correlation between overall antibiotic use and the increase in resistance did not reach statistical significance. It was observed that resistance increased despite only a slight increase in the use of a few antibiotics to which we attributed co-carriage of resistance genes. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Westville, 2012.

Studies have shown that the traditional healers have used Tulbaghia violacea (TV) (also known as ‘wild garlic’) for the treatment of a number of ailments including fever, tuberculosis, stomach problems, and oesophageal cancer. However, little is known with regards to the anticancer and antiproliferative properties of this plant. Therefore, this study investigated the effects of TV and domesticated garlic extracts on Jurkat cells, in order to determine whether or not these extracts possess anti-proliferative properties. Cultured Jurkat cells were treated with IC50 concentrations of garlic (14μg/ml), TV leaf (256μg/ml), TV bulb (225μg/ml) and TV stalk (216μg/ml) extracts as determined by the methylthiazol tetrazolium assay. Free radical production was measured using the thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) assays, while glutathione (GSH) concentration was measured using the GSH-Glo™ assay. The apoptosis inducing properties of each extract were measured using flow cytometry (Annexin V- Fluos and JC-1 assays) and luminometry (caspases 3/7, 8, 9 and ATP). Western blots were run to determine protein expression, while comet and DNA fragmentation assays were used to determine the level of DNA damage induced. Wild and domesticated garlic extracts induced a significant increase in malondialdehyde concentration ([MDA]), with TV bulb extract inducing the highest concentration (p<0.0001). A significant increase in NO concentration was observed in the bulb (p<0.0001) and stalk (p<0.001) extracts, and leaf (p<0.05) and stalk (p<0.05) TV extracts significantly increasing GSH concentration. The longest comet tails were observed in TV bulb extracts (p<0.0001) and comprised mainly of single strand breaks, while the comets induced following garlic exposure contained double strand breaks. All extracts, except TV leaf, increased the percentage of cells undergoing apoptosis. Tulbaghia violacea leaf induced a significant (p<0.0001) increase in percentage of cells undergoing necrosis, whereas TV bulb resulted in a significant (p<0.0001) decrease. All TV extracts induced caspase 3/7 and 9 activity, with the most significant increase in caspase 9 activity observed for TV leaf and bulb. No significant change in caspase 3/7 activity was evident for domesticated garlic. Cleavage of PARP and expression of NF B and HSP 70 occured for all extracts. However, HSP 70 was not differentially expressed. Exposure to wild and domesticated garlic extracts induced peroxidative lipid and DNA damage within the cells, indicating oxidative stress. This damage occurred in conjunction with increased percentage of cells undergoing apoptosis and expression of caspase 3/7. Therefore, these findings suggest that TV is inducing cell death through apoptosis in Jurkat cells using a number of mechanisms, including the induction of oxidative stress. This is of clinical significance, as cell death through apoptosis is the preferred method of action for anti-cancer drugs. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2012.