ResearchSpace
ResearchSpace is the institutional repository of the University of KwaZulu-Natal, unlocking knowledge, empowering impact, and preserving UKZN's research legacy.
Recent Submissions
Artemisia Afra crude aqueous extract induces NRF2-mediated antioxidant defence against oxidative stress and inhibits apoptosis via upregulation of hsp27 and HSP90 in A549 lung cancer cells.
(2024) Nkambule, Awande Comfort Monwabisi.; Khan , Rene.; Kumalo, Hezekiel Mathambo.
Lung cancer ranks first in mortality rates across all cancer types globally. Currently available treatment options are associated with undesirable outcomes for patients such as treatment related adverse events, low efficacy, and high costs. There have been ongoing efforts in novel drug discovery and development research using medicinal plants as a source for anti-tumour agents that will improve on these aspects. One such promising lead in this space is the South African plant Artemisia afra. In this study, the underlying mechanisms associated with the cytotoxicity of Artemisia. afra in A549 lung cancer cells were investigated following 48 hours exposure to the plant’s crude aqueous extract. Cytotoxicity was assessed using the MTT, ATP and mitochondrial membrane potential (ΔΨm) assays, and CYP3A4 activity was ascertained by luminometry. The free radical production and antioxidant response was determined using the TBARS, nitrates, luminometry and western blotting assays to measure ROS, RNS, GSH and antioxidant protein expression (SOD2, Gpx1, catalase), respectively. The Nrf2, HSP27 and HSP90 protein expression was detected by qPCR or western blotting. Cell death parameters such as caspase activity, phosphatidylserine (apoptosis) and necrosis were quantified by luminometry, and Bcl2 family proteins were ascertained by western blotting. The IC50 as per the dose-dependent MTT curve was determined to be at 260 μg/ml. Increased Artemisia afra metabolism by CYP3A4 (p<0.05) was observed in treated cells compared to the control, but ATP production was decreased (p<0.05) despite minimal changes in the ΔΨm. The Artemisia afra treatment significantly increased ROS production (p<0.05), which was met with a reactive spike in Nrf2 (p<0.05) gene expression. Concurrent increase in SOD2, Gpx1 (p<0.05) and catalase (p<0.05) protein expression, as well as GSH were noted. Little difference was recorded in the levels of nitrates. Pro-apoptotic Bax (p<0.05) was upregulated, while anti-apoptotic Bcl2 (p<0.05) was reduced. Intriguingly the initiator caspases, caspase 8 (p>0.05) and caspase 9 (p<0.05) were decreased in treated cells, in accordance with increased potent anti-apoptotic proteins HSP27 (p<0.05) and HSP90 (p<0.05), positing their role in inhibiting the initiator caspases but xIAP was not changed. Apoptosis was excluded as the major form of cytotoxicity in the treated cells given that the results showed a reduction in execution caspases, caspases 3/7 (p<0.05) and reduced PS externalisation (p<0.05). Necrosis was also excluded as the mode of cytotoxicity as necrosis, even though LDH levels were increased in the Artemisia afra treated A549 cells. The MTT and ATP assay analysis revealed a decline in cell viability after 48 hours of treatment. An antioxidant response was observed, but ROS were increased.
However, cell death by apoptosis was prevented by HSP. Taken together the current study confirmed that the Artemisa afra crude aqueous extract mediated cytotoxicity by oxidative stress, but demonstrated anti-apoptotic effects via HSP in A549 cells.
The effect of patulin on adrenergic receptor signalling and DNA methylation in C57BL/6 mouse livers.
(2024) Naidoo, Alisha.; Chuturgoon, Anil Amichund.; Ghazi, Terisha.
Background: Secondary metabolic products of fungi and mould are called mycotoxins, and they are usually hazardous to organisms. Patulin (PAT) is a mycotoxin most prevalent in apples and their products, such as juice and cider. PAT may threaten animal and human health by causing chronic effects including immunotoxicity, genotoxicity, teratogenicity, and carcinogenicity. Research demonstrates that PAT is hepatotoxic; however, its mechanism of action is unclear. The adrenergic receptors are altered during liver injury. The adrenergic receptors utilise the mitogen- activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) pathways. It is unclear if ARs are modulated by DNA methylation. DNA methylation is crucial for cell differentiation. Hence its dysregulation can lead to diseases such as cancer.
Aim: To determine the effect of PAT on global DNA methylation and adrenergic receptor signalling in C57BL/6 mouse livers.
Methods: In the livers of four C57BL/6 mice fed PAT (2.5 mg/kg BW) for 10 days:
qPCR determined the mRNA expression of alpha and beta-adrenergic receptors, as well as MAPK, MAPK14, ERK1/2, PI3K and AKT, DNMT1, DNMT3A, DNMT3B and MBD2. Western blot determined the protein expression of P38, ERK1/2, PI3K, DNMT1, DNMT3A, and MBD2. The ELISA assay was used to determine global DNA methylation levels.
Results: PAT significantly increased alpha-1A adrenergic receptor mRNA levels whilst decreasing alpha-2A, 2B, and all beta-adrenergic receptor expression, with beta-2 reduced significantly. PI3K’s decline was PAT-induced. PAT significantly increased AKT, MAPK, MAPK14, and ERK1 expression but significantly reduced ERK2 levels. PAT increased MBD2 and DNMT1 expression while significantly decreasing DNMT3A and 3B levels. PAT significantly increased and decreased the protein levels of P38 and ERK1/2 respectively. Additionally, a PAT- mediated increase in PI3K protein levels was observed. PAT significantly increased DNMT1 and increased DNMT3A and MBD2 expression. Significant global hypermethylation was PAT- induced.
Discussion/Conclusion: PAT significantly impacted alpha-1A and beta-2 adrenergic receptors which also utilise the MAPK/ERK/PI3K/AKT pathway. The dysregulation of these signalling cascades has been associated with altered expression of the adrenergic receptors. PAT-induced global hypermethylation. PAT disrupts adrenergic receptor signalling and modifies global DNA methylation, thus resulting in liver injury.
Learners’ learning with augmented reality resources.
(2025) Bunnoo, Shoueib Ibne Amine.; Govender, Desmond Wesley.
This thesis explores the impact of Augmented Reality (AR) resources on learners’ engagement, understanding, and retention of educational content, with a focus on multimodal, contextualised, and situated learning experiences. Situated within an interpretivist paradigm, this study employed qualitative methods, including focus-group interviews, art-based research, observations, and teachers’ reflective journals, to investigate how AR mediates learning processes that align with diverse learner needs. The study drew upon Activity Theory, Situated Cognition, and the VARK model to examine AR's capacity to support collaborative, personalised, and contextually grounded learning. Findings revealed that AR can serve as a transformative tool in education, bridging abstract and tangible knowledge by embedding complex content within immediate physical environments. Through the VARK model, AR was shown to accommodate diverse learning preferences, combining visual, auditory, kinaesthetic, and reading/writing modalities to create rich, holistic learning experiences. By integrating Activity Theory, this research uncovered how AR can reconfigure classroom dynamics, promoting learner-centred engagement and collaborative inquiry. The study’s methodological contributions included the novel application of art-based research, which allowed participants to express their experiences visually and emotionally, offering insights into the affective dimensions of AR. Additionally, the teachers’ reflective journals provided critical insights into the pedagogical adjustments and challenges encountered when integrating AR into instructional settings. These findings contribute to educational theory by extending current understandings of how AR can foster contextualised, experiential, and multimodal learning. Practical recommendations underscore AR’s potential for enhancing accessibility and inclusivity, offering a model for equitable, engaging, and adaptive learning environments. This research also advances the literature on educational technology and digital pedagogy, proposing AR as an essential tool for 21st century education that empowers learners, enriches teachers’ practices, and supports a shift towards more personalised, inclusive learning. Future research directions could include investigating the longitudinal impact of AR on knowledge retention, AR’s role in differentiated instruction for neurodiverse learners, and exploring policy implications for the ethical and equitable integration of AR in education.
Monsonia burkeana induces caspase-dependent apoptosis in Caco- 2 cells and nitrosative stress-induced necroptosis in HepG2 cells.
(2023) Naicker, Mayanka.; Khan, Rene.; Kumalo, Hezekiel Mathambo.
Introduction: Cancer is one of the leading causes of death globally. Increased incidence and mortality rates of colorectal and liver cancer have been reported in South Africa and worldwide. Cytotoxic side effects associated with current treatments have sparked interest in using plant phytochemicals as a potential alternate, cost-effective cancer therapeutic. Monsonia burkeana Planch. Ex Harv, also known as "special tea", is a medicinal plant native to southern Africa that treats various ailments. It has also shown potential application in anticancer therapy. This study investigated the anticancer effects of M. burkeana crude aqueous extract in the Caco-2 and HepG2 cell lines.
Methods: The target cells were reconstituted in CCM and treated with 0 - 5000μg/ml of M.burkeana plant extract for 48 hours during the MTT assay to obtain the 20% and 50% inhibitory concentration (IC20 and IC50), which was used for experiments that followed. The cytotoxic effects were further evaluated using the LDH and CYP3A4 activity assay to determine oxidative breakdown and assess the ATP and JC-10 levels to measure mitochondrial integrity. The antioxidant response of M. burkeana involved conducting the TBARS/NOS assay to extrapolate reactive oxygen and nitrogen species, GSH quantification, and western blotting to detect (SOD, NRF2, iNOS) protein expression. The mRNA gene expression of Gpx and OGG1 was evaluated using qPCR. To assess cell death, the Annexin-V assay distinguished apoptotic and necrotic cells, caspase activation assays were conducted as a marker of apoptosis, and western blotting determined the expression of the following proteins: p53, p-p53, BAX, NFB, cIAP2, cleaved caspase 3 and BCL-2. Gene expression of MLKL, RIP1, RIP3, NFB, and TNF-α was also assessed to evaluate its role in cell death. Lastly, data analysis was conducted using statistical tests in GraphPad Prism.
Results: Cytochrome P450 3A4 activity increased for both cell lines, causing a dose-dependent decrease in cell viability in Caco-2 cells and HepG2 cells, with an IC50 value of 293.8 μg/ml and an IC20 value of 169.8 μg/ml in Caco-2 cells. In HepG2 cells, the IC50 value was 335.4 μg/ml of M. burkeana extract, and the IC20 value was 154.9 μg/ml. The decreased ATP concentration in Caco-2 and HepG2 cells for both treatments was consistent with the increased ΔΨm, confirming a reduced metabolic activity. Decreased MDA levels indicating lipid peroxidation occurred for both cell lines, while increased OGG1 for the Caco-2 IC20 treatment suggests DNA oxidation for this treatment only. Nitrite levels decreased for both treatments in Caco-2 cells but increased in HepG2 cells. There was also a decrease in iNOS protein expression for both cell lines. Membrane disruption was validated by increased LDH for both cell lines and HepG2 cells were associated with RNS-induced membrane disruption. Oxidative stress is implied due to decreased GSH concentration and upregulation of SOD2 protein expression at both treatment concentrations for Caco-2 and HepG2 cells. However, Gpx-1 decreased for Caco-2 cells and the IC20 treatment in HepG2 cells. There was an associated upregulation of NRF-2 protein expression for both cell lines at the IC50 treatment concentrations to regulate antioxidant proteins. Initiator caspase 8 activity increased for both treatment concentrations in Caco-2 cells, implying that in Caco-2 cells, apoptosis was stimulated via the extrinsic pathway. In addition, intrinsic apoptosis was initiated in the IC20-treated Caco-2 cells as caspase 9 activity increased. Caspase 8 and caspase 9 activity decreased for both treatment concentrations in HepG2 cells. The p-p53/p53 ratio decreased for both treatments in Caco-2 cells. Thus, p53 did not mediate the transcription of pro-apoptotic BCL-2 family genes such as BAX, which dropped in both treatment concentrations. Anti-apoptotic BCL-2 was also reduced in Caco-2 cells. In HepG2 cells, the protein expression of p-p53/p53 remained relatively unchanged for IC20- treated cells and increased for IC50-treated, but the BAX decreased for IC20, and BCL-2 protein expression increased for the IC50 treatment concentration. M. burkeana facilitated the execution of apoptosis in both cell lines, as caspase 3/7 was increased and phosphatidylserine was externalised, but necrosis was also increased. There was downregulation of TNF in Caco-2 cells, and decreased RIPK1, RIPK3 and MLKL for both treatment concentrations corresponding with increased cIAP2. In HepG2 cells, there was an increase in RIPK1 gene expression for both the IC20 and IC50 treatment concentrations, decreased cIAP2 protein expression, increased RIPK3 and MLKL gene expression.
Conclusion: According to the results, M. burkeana crude aqueous extract caused caspase-dependent apoptosis in Caco-2 cells and nitrosative stress-induced necroptosis in HepG2 cells, which validates that M. burkeana can be further explored as an anticancer therapeutic.
Exploration of online teaching and learning experiences of technical and vocational education college lecturers during the coronavirus disease pandemic.
(2023) Singh, Adheesh.; Mnisi, Thoko Esther
The COVID-19 pandemic disrupted how teaching and learning was conducted, forcing the transfer from traditional contact delivery mode to online delivery mode. The transition to an online mode of delivery was not planned.; It was a significant disruption to Technical and Vocational Education and Training (TVET) lecturers’ usual mode of operation for which they had been trained and used post-graduation from training school. This study explores online teaching and learning experiences of TVET during COVID-19. The study adopted a qualitative methodology to explore how COVID-19 impacted teaching and learning online during the COVID-19 pandemic. A case study approach was adopted with a focus on one TVET college in SA. The population of the study were all the lecturers of the selected TVET college. Purposive sampling was used to select the sample of five lecturers. Semi-structured interviews were the data production tool. The data production method was audio-recorded face-to-face interviews following COVID-19 regulations. Data analysis was conducted using thematic data analysis. TVET lecturers' significant challenges during and after the transition to online teaching, included internet connectivity challenges, absence of human contact and connection, absence of appropriate ICT gadgets for online teaching and learning and lack of digital skills. Lack of institutional support was another negative experience of TVET lecturers as there were no resources for both leaners and lecturers and no online training provided. The study recommends that the TVET colleges equip the lecturers with online skills and provide resources that will result in effective online teaching and learning.