Browsing by Author "Pool, Edmund J."
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Item The effects of endocrine disrupting chemicals on biomarkers of inflammation produced by lipopolysaccharide stimulated raw264.7 macrophages(MDPI, 2019) Makene, Vedastus W.; Pool, Edmund J.Endocrine disrupting chemicals (EDCs) are common pollutants in the environment and can induce disruption of the endocrine and immune systems. The present study evaluated the effects of selected common environmental EDCs on secretion of inflammatory biomarkers by RAW264.7 cells. The EDCs investigated were Estradiol (E2), 5α-dihydrotestosterone (DHT), and Bisphenol A (BPA). To evaluate if the effects caused by EDCs were modulated by steroid hormone receptors, antagonists of estrogen and androgen receptors were used. The steroid receptor antagonists used were Tamoxifen, an estrogen receptor antagonist, and Flutamide, an androgen receptor antagonist. Secretion of biomarkers of inflammation, namely nitric oxide (NO) and interleukin 6 (IL-6), were monitored. The NO was determined using Griess reaction and IL-6 was measured by enzyme linked immunosorbent assay (ELISA). Although 5 µg/mL E2, DHT, and BPA were not toxic to RAW264.7 cell cultures, the same treatments significantly (p < 0.001) reduced both NO and IL-6 secretion by lipopolysaccharide (LPS)-stimulated RAW264.7 cell cultures.Item The effects of silver nanoparticles on RAW 264.7. Macrophages and human whole blood cell cultures(University of the Western Cape, 2019) Lategan, Kim L.; Walters, Chavon R.; Pool, Edmund J.Silver nanoparticles (AgNPs) are commonly found in consumer products due to their antimicrobial properties. This study evaluated the effects of AgNPs on the murine macrophage cell line RAW 264.7 and human whole blood cell cultures (WBCs). Effects of AgNPs on RAW cells were assessed in the presence or absence of lipopolysaccharide (LPS). Effects of AgNPs on WBCs were monitored under basal conditions and in the presence of either LPS or phytohaemmagglutinin (PHA). AgNPs were cytotoxic to WBCs at 250 μg/ml. Under basal conditions, RAW cells = 62.5. μg/ml and WBCs > 25 μg/ml AgNPs induced biomarkers associated with inflammation. Under LPS stimulated conditions, 250 μg/ml AgNP inhibited biomarkers associated with inflammation for both cultures. Under basal conditions, and in the presence of 250 μg/ml AgNP, WBCs produced acquired immune system cytokines IL-10 and IFNγ. IL-10 synthesis by WBCs was partially inhibited by 250 μg/ml AgNP in the presence of PHA. Proteome profiles of RAW cell supernatants show that AgNPs modulate biomarkers associated with inflammation. WBCs proteome analysis shows modulation of biomarkers associated with anti-inflammatory effects.Item The immune-modulating activity of Artemisia afra(University of the Western Cape, 2010) Kriel, Yusra; Pool, Edmund J.; Faculty of ScienceThis study shows that herbs can be effectively screened for potiential bio-activity using in vitro methods. Further studies will be needed to better explore Artemisia afra’s effect on immunoregulation, particularly long term effects of the herb on the immune system and its effect on other disease states.Item The immune-modulating activity of Sutherlandia frutescens(University of the Western Cape, 2010) Kisten, Najwa; Pool, Edmund J.; NULL; Faculty of ScienceThe aim of this study was to investigate the effects of Sutherlandia frutescens on the inflammatory response and T cell differentiation in vitro using cytokines as biomarkers. Whole blood cells containing various concentrations of Sutherlandia frutescens were stimulated in vitro with either Lipopolysaccharide (LPS) or Phytohaemagglutinin (PHA). Results show that Sutherlandia frutescens is not toxic at any of the concentrations tested. The addition of Sutherlandia frutescens at high concentrations to the stimulated whole blood cell cultures reflects a significant down regulation of Interleukin(IL) 6 and IL-10 compared to the control (P<0.05) hence suppressed the inflammatory and humoral immune response. Results obtained for Inteferon-gamma (IFN ) shows that Sutherlandia frutescens is donor specific as it reflects both up and down regulation in the release of IFN at the concentrations tested. The in vitro data generated by this study supports the use of Sutherlandia frutescens in the management of inflammatory conditions and allergies such as asthma. However the effects of Sutherlandia frutescens on cell mediated immunity was found to be donor specific. Further investigation of Sutherlandia frutescens on cellular immunity is advised.Item An in vitro study on the immunotoxicity of sewage effluents discharged into the Eerste River-Kuils river water catchment system(2008) Magcwebeba, Tandeka; Pool, Edmund J."The aim of the study was to use in vitro human whole blood cultures to screen the water samples collected from the Eerste/Plankenbrug river system for cytotoxicity and inflammatory activity and for the first time investigate the impact on the cell- mediated and humoral immune pathways. Water samples were collected fronm the sites during the dry summer season and rainy winter season. Blood was collected from the healthy male volunteers and diluted with RPMI 1640. For cytotoxicity and inflammatory activity 2.5ul of blood for 18-20 hrs at 37 C... This study shows that waster from the Plankenbrug River is heavily polluted by contaminants from both the agricultural area and informal settlement of Kayamandi. These contaminants can be potentially immunotoxic during the summer season and they can result in inflammatory diarrheal disease and immunosuppression in exposed individuals..."Item An in vitro study on the immunotoxicity of South African beer(University of the Western Cape, 2008) Neethling, Michelle; Pool, Edmund J.; Faculty of ScienceTraditionally brewed beers are of cultural and economic importance to many African nations. The presence of mycotoxins in African beer is a topic that needs to be addressed, since most African countries have a climate of high humidity and temperature that favours the growth of moulds. Mycotoxins challenge not only the health of animals and humans, but also the economy, especially in underdeveloped countries where contamination is most likely. Literature proves that mycotoxins depict various effects on the immune system including immunotoxicity. Beer analysis is therefore of utmost importance in order to evaluate organoleptic characteristics, quality, nutritional value as well as safety. The aims of this study involve the analysis and comparison of traditional and commercial beer in terms of physical characteristics, mycotoxin concentrations as well as effects on specific immune pathway biomarkers in order to elucidate possible immunotoxicity.Item The toxicity of silver nanoparticles(University of the Western Cape, 2012) Motsoeneng, Khothatso Patricia; Pool, Edmund J.; Petrik, LeslieUnavailability and contamination of available water resources are major factors contributing to adverse health conditions worldwide. AgNPs present a potential strategy for water purification; however, their ability to accumulate in organs such as the kidneys, lungs and spleen is a possible source of toxicity. This study investigates the toxicity of AgNPs to Saccharomyces cerevisiae (S. cerevisiae). S. cerevisiae is an excellent model organism for assessing toxic compounds that affect eukaryotic organisms due to their ease of cultivation. AgNPs were prepared by photo-reduction of silver nitrate with OSRAM Vitalux lamp (300 W and 230 V) in the presence of stabilizing agents such as polyvinylpyrrolidone and citric acid, yielding AgNPs. The effects of varying the concentration of the stabilizing agent, time of exposure to the light source, and pH were investigated. The formation of AgNPs was analysed by ultra-violet spectroscopy (UV-Vis) and transmission electron microscope techniques. The results showed that the AgNPs absorbed ultra-violet radiation between 400 and 500 nm and TEM images showed the particles to be both spherical and needle-like in shape. The shapes of the AgNPs were largely dependent on the synthesis method applied. The toxicity of AgNPs was assessed using metabolic activity of yeast cells as biomarker andmonitored with of the chromogenic assay, XTT. S. cerevisiae was introduced into different concentrations of AgNPs and incubated at 37oC for 72 h. After the incubation, XTT assay was performed to assess the cell viability. The XTT results showed that high concentration of AgNPs (100 µg/mL) inhibited the growth of S. cerevisiae. The synthesis of AgNPs and theassessment of their toxicity on S. cerevisiae was thus undertaken and established in this work.