Charlette Tiloke

Moringa oleifera Gold Nanoparticles Modulate Oncogenes, Tumor Suppressor Genes, and Caspase-9 Splice Variants in A549 Cells.

Gold nanoparticles (AuNPs) facilitate cancer cell recognition and can be manufactured by green synthesis using nutrient rich medicinal plants such as Moringa oleifera (MO). Targeting dysregulated oncogenes and tumor suppressor genes is crucial for cancer therapeutics. We investigated the antiproliferative effects of AuNP synthesized from MO aqueous leaf extracts (MLAuNP) in A549 lung and SNO oesophageal cancer cells. A one‐pot green synthesis technique was used to synthesise MLAuNP. A549, SNO cancer cells and normal peripheral blood mononuclear cells (PBMCs) were exposed to MLAuNP and CAuNP to evaluate cytotoxicity (MTT assay); apoptosis was measured by phosphatidylserine (PS) externalization, mitochondrial depolarization (ΔΨm) (flow cytometry), caspase‐3/7, −9 activity, and ATP levels (luminometry). The mRNA expression of c‐myc, p53, Skp2, Fbw7α, and caspase‐9 splice variants was determined using qPCR, while relative protein expression of c‐myc, p53, SRp30a, Bax, Bcl‐2, Smac/DIABLO, Hsp70, and PARP‐1 were determined by Western blotting. MLAuNP and CAuNP were not cytotoxic to PBMCs, whilst its pro‐apoptotic properties were confirmed in A549 and SNO cells. MLAuNP significantly increased caspase activity in SNO cells while MLAuNP significantly increased PS externalization, ΔΨm, caspase‐9, caspase‐3/7 activities, and decreased ATP levels in A549 cells. Also, p53 mRNA and protein levels, SRp30a (P = 0.428), Bax, Smac/DIABLO and PARP‐1 24 kDa fragment levels were significantly increased. Conversely, MLAuNP significantly decreased Bcl‐2, Hsp70, Skp2, Fbw7α, c‐myc mRNA, and protein levels and activated alternate splicing with caspase‐9a splice variant being significantly increased. MLAuNP possesses antiproliferative properties and induced apoptosis in A549 cells by activating alternate splicing of caspase‐9. J. Cell. Biochem. 117: 2302–2314, 2016.

Biosynthesis of palladium nanoparticles by using Moringa oleifera flower extract and their catalytic and biological properties

The biosynthesis of nanostructured biopalladium nanoparticles (PdNPs) from an aqueous solution of crystalline palladium acetate is reported. For the synthesised PdNPs in solution, an agroforest biomass waste petal of Moringa oleifera derived bis-phthalate was used as natural reducing and biocapping agents. Continuous absorption in the UV region and subsequent brown colour change confirmed the formation of PdNPs. A strong surface plasmon peak for PdNPs occurred at 460nm. PdNPs were characterized by SEM with EDX, FTIR, TEM and DLS. The chemical composition of the aqueous extract was determined by GC-MS coupled with FTIR and 1NMR. The catalytic degradation effect by PdNPs on industrial organic toxic effluents p-nitrophenol (PNP) and methylene blue dye was monitored by UV Spectroscopy. On the other hand PdNPs catalysed the base mediated suzuki coupling reaction for biphenyl synthesis, in water. Moreover, PdNPs were found to be reusable catalysts. Toxicity studies of PdNPs showed that the death of brine shrimp to be <50%. Therefore, PdNPs displayed potential for further anticancer studies via tumour cell lines. The in vitro cytotoxicity evaluation of the extract capped nanoparticles was carried out using human lung carcinoma cells (A549) and peripheral lymphocytes normal cells by MTT cell viability assay. Also, PdNPs showed antibacterial activity against Enterococcus faecalis among the different tested strains, including Bacillus cereus, Staphylococcus aureus, Esherichia coli and Candida albicans, Candida utilis.

Fusaric acid induces oxidative stress and apoptosis in human cancerous oesophageal SNO cells

ABSTRACT Oesophageal cancer (OC) is a global problem incrementally incident among black South African males. The high incidence of OC may be due to the consumption of corn as a staple, often contaminated with mycotoxins. Fusaric acid (FA), a neglected mycotoxin, is known to disrupt mitochondrial energy metabolism, chelates divalent metal cations and induces cell death in plants. This study investigated FA‐induced cytotoxicity and apoptotic induction in the SNO OC cell line. Cells were treated with FA (IC50 = 78.81 &mgr;g/mL; 24 h; MTT assay) and assayed for oxidative stress and membrane damage (TBARS, LDH cytotoxicity and glutathione), apoptotic induction (ATP levels, caspase‐8, ‐9, ‐3/7 activities) (Luminometry), single strand DNA and nuclear fragmentation (Comet and Hoechst assay). Additionally, relative expression of pro‐ and anti‐apoptotic proteins were determined (Western Blotting). Significant antioxidant depletion was consistent with a concomitant increase in ROS‐induced lipid peroxidation and extracellular LDH levels. FA induced apoptosis by significantly increasing Bax expression and caspase‐8, ‐9 and ‐3/7 activities whilst decreasing ATP levels and Bcl‐2 expression. Further, FA significantly increased comet tail lengths, PARP‐1 expression and late stage apoptotic body formation in SNO cells. This study shows that FA is cytotoxic and induces increased apoptosis in SNO cells. HIGHLIGHTSFusaric acid (FA) reduced metabolic activity and cell viability in SNO cells.FA increased ROS‐induced lipid peroxidation with a concomitant decrease in glutathione.FA decreased ATP levels and increased LDH leakage from SNO cells.FA induced apoptosis by increasing caspase‐3/7, ‐8 and ‐9 activities and DNA damage.

Toxicity assessment of mycotoxins extracted from contaminated commercial dog pelleted feed on canine blood mononuclear cells

Raw ingredients of pet food are often contaminated with mycotoxins. This is a serious health problem to pets and causes emotional and economical stress to the pet owners. The aim of this study was to determine the immunotoxicity of the most common mycotoxins (aflatoxin, fumonisin, ochratoxin A and zearalenone) by examining 20 samples of extruded dry dog food found on the South African market [10 samples from standard grocery store lines (SB), 10 from premium veterinarian lines (PB)]. Pelleted dog food was subjected to extraction protocols optimized for the above mentioned mycotoxins. Dog lymphocytes were treated with the extracts (24 h incubation and final concentration 40 μg/ml) to determine cell viability, mitochondrial function, oxidative stress, and markers of cell death using spectrophotometry, luminometry and flow cytometry. Malondialdehyde, a marker of oxidative stress showed no significant difference between SB and PB, however, GSH was significantly depleted in SB extract treatments. Markers of apoptosis (phosphatidylserine externalization) and necrosis (propidium iodide incorporation) were elevated in both food lines when compared to untreated control cells, interestingly SB extracts were significantly higher than PB. We also observed decreased ATP levels and increased mitochondrial depolarization in cells treated with both lines of feed with SB showing the greatest differences when compared to the control. This study provides evidence that irrespective of price, quality or marketing channels, pet foods present a high risk of mycotoxin contamination. Though in this study PB fared better than SB in regards to cell toxicity, there is a multitude of other factors that need to be studied which may have an influence on other negative outcomes.

The Antiproliferative and Antibacterial Effect of Moringa oleifera-Mediated Gold Nanoparticles: A Review

South Africa’s (SA’s) mortality rates are increasing due to increased cancer diagnosis. In addition, bacterial infections are on the rise with increasing antibacterial resistance. Current chemotherapies and antibacterial agents are expensive with many side-effects; therefore alternative therapies are actively being investigated. A medicinal tree, Moringa oleifera (MO), is found throughout SA and used in traditional treatment of a variety of ailments including cancer and microbial infections. All parts of the tree are used for medicinal purposes including leaves, flowers, bark, seeds and seedpods (drumstick). The use of MO extracts has been beneficial for people across many communities as a food source in addition to its medicinal properties. Nanoparticles have a wide range of biomedical applications and are showing potential as anticancer and antibacterial agents. Their relative smaller size (1–100 nm) facilitates their mode of action against diseases. Nanoparticles are synthesised chemically or via plant extracts which are environmentally friendly and less toxic. MO can be used for nanoparticle synthesis such as gold nanoparticles (AuNPs) using a one-pot green synthesis technique. Therapeutic applications of AuNPs have been assessed both in vitro and in vivo with positive outcomes. The review aims to discuss the therapeutic potential of AuNPs as anticancer and antibacterial agents.

Cytotoxic Effect of a Novel Synthesized Carbazole Compound on A549 Lung Cancer Cell Line

Increased death rates due to lung cancer have necessitated the search for potential novel anticancer compounds such as carbazole derivatives. Carbazoles are aromatic heterocyclic compounds with anticancer, antibacterial and anti-inflammatory activity. The study investigated the ability of the novel carbazole compound (Z)-4-[9-ethyl-9aH-carbazol-3-yl) amino] pent-3-en-2-one (ECAP) to induce cytotoxicity of lung cancer cells and its mechanism of action. ECAP was synthesized as a yellow powder with melting point of 240-247 °C. The 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), lipid peroxidation and comet assays were used to assess the cytotoxic effect of the compound on A549 lung cancer cells. Protein expression was determined using western blots, apoptosis was measured by luminometry (caspase-3/7, -8 and -9) assay and flow cytometry was used to measure phosphatidylserine (PS) externalisation. ECAP induced a p53 mediated apoptosis of lung cancer cells due to a significant reduction in the expression of antioxidant defence proteins (Nrf2 and SOD), Hsp70 (p < 0.02) and Bcl-2 (p < 0.0006), thereby up-regulating reactive oxygen species (ROS) production. This resulted in DNA damage (p < 0.0001), up-regulation of Bax expression and caspase activity and induction of apoptosis in lung cancer cells. The results show the anticancer potential of ECAP on lung cancer.

HIV induced nitric oxide and lipid peroxidation, influences neonatal birthweight in a South African population

HIV has been implicated in adverse birth outcomes, due to increased oxidative stress and inflammation. In addition, HIV has been reported to increase nitric oxide levels. Therefore the combined exposures to HIV and traffic-related air pollution, within South Durban, South Africa (SA), may lead to adverse birth outcomes. However, the exact mechanism is still unknown; this study aimed to identify a potential mechanism. First, the influence of HIV on oxidative and nitrosative stress markers in pregnant women was assessed. Secondly, the effect of these stress makers and exposure to oxides of nitrogen (NOx) on neonatal birthweight (BW) was evaluated. Finally, the effect HIV and traffic-related pollution exposure has on the oxidative and endoplasmic profile and epigenetic regulation of Nrf2-Keap1 pathway by miR-144 and miR-28 in pregnant women was determined. Women, in their third trimester with singleton pregnancies, who were HIV+ and HIV-, were recruited from Durban, SA. Biomarker levels of serum nitrites/nitrates (NO) and malondialdehyde (MDA) were analysed and mRNA expression levels of oxidative and endoplasmic stress response genes were assessed. Land regression modelling was performed to determine NOx exposure levels. HIV exposure during pregnancy was associated with increased NO levels. NO was shown to reduce neonatal BW. NO and MDA was found to reciprocally increase each other, with HIV differentially influencing MDAs effect on BW. HIV down-regulated miR-144 which was negatively associated with Nrf2, suggesting a potential mechanism for HIV associated chronic oxidative stress. This study proposes that NO plays a key role in neonatal BW reduction in response to HIV and traffic-related air pollution.

Moringa oleifera and their phytonanoparticles: Potential antiproliferative agents against cancer

Cancer is classified as one of the leading causes of global mortality. It has affected millions of people, often with poor prognosis. Having severe side-effects with conventional chemotherapy, alternate drugs and therapies are actively being investigated. There is a need for innovative drug discovery and design as existing cancer therapies are costly and not readily available. Ayurveda and traditional medicine have utilised natural resources such as plants and trees as part of their regime to treat various illness and diseases with positive outcomes. One such tree is Moringa oleifera (MO). Almost all parts have shown to be effective against several ailments including cancer which was attributed to the bioactive constituents. Targeted therapies had led to the development of nanoparticles which are extremely effective in various biomedical applications due to their small size. Green synthesis of gold nanoparticles have great potential as naturally occurring plants and trees such as MO can be used in the synthesis process. The resultant gold phytonanoparticles are useful in cancer therapies with improved survival rates and quality of life. The review highlights the importance of MO in natural medicine, synthesis of phytonanoparticles and the fundamental role as a potential antiproliferative agent against cancer.

The Chemotherapeutic Potential of Gold Nanoparticles Against Human Carcinomas: A Review

Cancer is a leading cause of death in South Africa (SA). Nanoparticles (NPs) have potential uses in cancer therapies due to their size (1–100 nm). Nanoparticles are stabilized chemically or via the use of plants. Moringa oleifera (MO), found widely in SA, possesses medicinal properties with MO leaves (MOE) and flowers (MF) with high nutritional value. MOE and MF can be utilized in the synthesis of gold nanoparticles (AuNPs). Apoptosis maintains homeostasis and disruptions to this lead to cancer pathogenesis. Oncogenes encourage tumor progression and dysregulation by tumor suppressor genes ensures that abnormal cells continue in the cell cycle. They are often resistant to chemotherapy. The review aims to present and discuss the potential of AuNPs as a chemotherapeutic agent in targeting oncogenes and tumor suppressor genes with negligible effects on normal cells. Furthermore, the synthesis (one-pot green synthesis technique) of these novel nanoparticles can be beneficial for cancer therapies.

Moringa oleifera gold nanoparticles modulate oncogenes, tumor suppressor genes, and Caspase-9 splice variants in A549 cells

Oesophageal cancer ranks the ninth most common malignancy and the sixth most frequent cause of cancer death in the world, with geographic variations in incidence and histological subtypes. In China, oesophageal squamous cell carcinoma (ESCC) accounts for >90% of the total incidence of oesophageal cancer; approximately 300 000 new cases of oesophageal cancer are diagnosed every year in the world of which almost half originate in the high-incidence regions of China.1 According to the Hong Kong Cancer Registry in 2012, ESCC ranked the tenth most frequent cancer death among all other cancers for both sexes. The current treatment modalities for ESCC achieve relatively suboptimal survival and cure rates.2 To further improve the management of this disease, novel prognostic markers for ESCC need to be identified. Gene amplification and overexpression have been suggested to be the major genomic aberrations involved in the pathogenesis of ESCC. Previously, our group reported a novel oncogene JK-1 in ESCC located in the chromosomal region 5p15.1-2; it frequently shows amplification in ESCC and other solid tumours.3 Our collaborators also reported the overexpression of JK-1 mRNA in colorectal tumours, providing the first evidence of the significance of JK-1 mRNA overexpression in gastrointestinal cancer.4 Nonetheless, there are no studies of JK-1 protein expression in ESCC or its correlation with clinicopathological features. Identifying novel histopathologial tumour markers for ESCC is important. Correlating the levels of these protein signals in tissues with the respective clinicopathological features enables better management of the disease. Detection of Hong Kong Med J 2018;24(Suppl 3):S41-4 HMRF project number: 01121886Results: Significant differences in serum leptin levels between the control and the study group were observed. No differences between the pre and post-operative serum leptin levels. Immunohistochemistry studies showed that leptin and its receptors were positively expressed in the majority of breast cancer tissue and this expression was significantly correlated with the distant metastasis of the breast cancer.T aim of the present study is to explore the possible mechanism of ID4 gene in breast tumorigenesis by observing the methylation status of ID4 gene promoter in breast cancer and its relationship with clinical pathological characteristics. The methylation level of ID4 promoter region in breast tumor (n=40) and normal tissue (n=20) specimens was detected by pyrosequencing and the correlation between the methylation level of ID4 gene and clinical pathological characteristics was analyzed. The methylation level of ID4 in MM-453 cell line before and after demethylation treatment was detected by pyrosequencing and the mRNA expression of ID4 was detected by RT-PCR. The methylation level of ID4 promoter region in breast tumor tissue was (31.16±1.5%) and significantly higher than that in normal breast tissue (19.89±0.22%). The methylation level of ID4 gene in ER positive breast cancer tissue was (36.57±1.97%) and significantly higher than that in ER negative group (27.91±1.83%). After the demethylation treatment in MM-453 cell line, the methylation level of ID4 gene decreased and the mRNA expression of ID4 increased remarkably. ID4 gene may play an important role in the breast cancer formation by a variety way including gene promoter hypermethylation, especially in ER positive breast cancer.C cancer is one of the most prevalent and deadly female cancers worldwide and is especially common in developing countries. Various surveys have been conducted in the recent years that revealed various insights into the knowledge, perceptions and practices of the different communities regarding cervical cancer. Studies clearly indicated that women in different communities especially in lower resource settings have limited knowledge about cervical cancer, it’s link with Human Papilloma Virus (HPV), prevention and even less or not at all familiar with screening and HPV vaccine. That lack of awareness may result in poor utilization of HPV vaccine and screening services, even when these are available. The prevention of cervical cancer needs a number of factors to be effectively in place like the awareness of cervical cancer etiology, barriers including intrapersonal, interpersonal and institutional barriers to assessing health care need to be removed, knowledge about the fact that HPV vaccination prevents most of the cervical cancer and screening can detect precancerous lesions which can be mitigated by treatment. Therefore, there is a major need to develop educational intervention programs to address HPV vaccine safety concerns and educate the community by targeting the risk population on risk factors for cervical cancer and practices related to its prevention and early detection. Improvement of cervical health literacy level is a major step towards the prevention and early detection of this dreadful disease.A object segmentation is one of the most important tasks in image analysis. While a universal schema for this task is seemingly not shortly attainable, practical solutions under different circumstances have been developed in the past couple of decades. Most of the previous works were based on machine learning. In contrast, our agenda differs from them in that we try to achieve satisfactory segmentation with a limited number of examples. Our idea is to leverage object matching in the segmentation model, thereby object segmentation is automated or object matching becomes precise in pixel level. In this talk, I’ll introduce two of my recent works in this direction. Specifically, I’ll introduce how object matching model can be integrated with two different types of segmentation models, namely the Markov random field model and the active contour model, to achieve automatic object segmentation. Discussions on their uses in radiographic image analysis would be encouraged.L biopsies are non-invasive blood diagnostic tests that detect circulating tumor cells (CTCs) and/or fragments of tumor DNA that are shed into the blood from the primary tumor and from metastatic sites. This approach can have an enormous diagnostic and treatment implication for oncology that can transform clinical oncology practice and that it is part of the personalized medicine. Whereas tumor genome sequencing is already central to inform treatment decisions and the management of oncological patients, the liquid biopsy may represent the non-invasive approach to monitor tumor genomic changes in real time. This will allow clinicians to ensure that the therapy they have selected based on a particular molecular target, remains relevant and eventually observe the emergence of any resistance. Eventually, it would be possible to observe if any new molecular targets appear that could be suitable for a different treatment. All this could help to provide patients with the right treatment for the right target without delay. Liquid biopsies also present us with a unique opportunity to move forward with our understanding of metastatic disease development and they may help to identify signaling pathways involved in cell invasiveness and metastatic competence. Moreover these tests have the possibility to be used in screening programs at least for some kind of cancers. At the end, the liquid biopsy can revolutionize cancer care, providing clinicians with rapid access to information on a molecular level at diagnosis, thereby optimizing treatment choices.B circulating microRNAs are known as novel and validated biomarkers for application in early detection of diseases including cancers. The aim was to design and fabricate precise sensors for quantification of miRNAs in real samples (serum/plasma) without any sample manipulation. Two sensors (an electrochemical biosensor and nanobiosensor) were developed for quantification of miR-155, as a biomarker related to the early phase of breast cancer expression. Both sensors showed high specificity and selectivity, so that they could discriminate between target miR-155 and single-base mismatch, three-base mismatch, completely unmatched oligonucleotides. Reproducibility, stability and functionality of the sensors in the real samples (serum/plasma) were found to be significant. Both sensors had a low detection limit and wide linear ranges with simplicity, less consumed time and low cost, which were superior to the most of previously published works. It seems our method can be introduced to be used in clinical labs and also detection of other miRNA biomarkers through other optimizations.