Screening medical plants for potential immunomodulatory action on macrophages in the fight against mycobacterium tuberculosis.
- Authors: Shauli, Mathulo Mthabiso
- Date: 2023-12
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/11260/12744 , vital:76161
- Description: Pulmonary tuberculosis remains the leading cause of death in developing countries, it is an ancient disease that was discovered in the eighteenth centuries. The World Health Organization (WHO) tuberculosis (TB) regimen entails the first line drugs, rifampicin, isoniazid, ethambutol, and pyrazinamide. These drugs are taken for long periods and the load is high, they carry some side effects like liver damage and peripheral neuropathies, hence pyridoxine that is administered with TB treatment to mitigate the toxic effects to peripheral nerves. Drug resistance has emerged because of unbearable side effects of TB treatment in TB patients. In view of all these collective challenges of TB drugs, this study draws its motivation towards exploring natural products in the form of medicinal plants toward inventing new therapies that could be easily available and safer, and the macrophages were considered the therapeutic target for this study as they are the primary cells that get infected by Mycobacterium in the lung. Therefore, the study aimed at screening medicinal plants used by traditional healers and herbalists for the management and control of signs and symptoms related to pulmonary tuberculosis, for potential immunomodulatory activity on RAW 264.7 cells, and the objectives were; to obtain information on indigenous plants used to treat pulmonary tuberculosis (PTB) from traditional healers and herbalist, to test the cytotoxicity of crude extracts on macrophages and hepatocytes (C3A cells), to determine the polarizing effects of crude extracts on macrophages, to determine the polarizing effect of the crude extract fractions on macrophages and to finally isolate and characterize the compounds in active fraction. vii All medicinal plants investigated in this study were collected through ethnobotanical survey, authenticated in Botany Department, dried, and extracted in 70% ethanol solvent. The dried crude extracts were screened for toxicity using 3-4,5-dimethylthiazole-24-25 diphenyl tetrazolium bromide (MTT) technique on RAW264.7 macrophages and dual fluorescence staining technique on C3A cells at concentration 50, 100 and 200μg/ml in cell culture system. Seven medicinal plants displayed dose dependency toxicity, while three plants did not show any signs of toxicity with cell viability maintained at 100%. The three medicinal plants (Anthrixia phylicoides, Lippia javanica and Sanicula elata) were further investigated for immunomodulatory activity (Griess method) and antioxidant activity (CellROX® Orange and Hoechst 33342). Lippia and Anthrixia were found to be anti-inflammatory with low amounts of nitric oxide (NO) production, while Sanicula displayed a considerable amount of nitric oxide when compared to the lipopolysaccharides (LPS) control. NO was the biological marker measured that demonstrated the immunomodulatory effect of plants on macrophages. Furthermore, the two plants showed antioxidant activity on liver cells at higher concentration (100 and 200μM) while Sanicula exhibited antioxidant activity across all tested concentrations. Compound profiling for Sanicula was therefore determined by UPLC-MS hyphenation technique and the major compounds profiled were phenolic compounds. The crude extracts of Sanicula were further partitioned into five fractions using partition solvent technique (n-hexane, Dichloromethane, ethyl acetate, N-butanol, and water). Anti-inflammatory activity was repeated on the five fractions, and Dichloromethane fraction and water fraction drove the macrophage switching towards the M1 phenotype viii with considerable amount of NO produced. Compound isolation and identification was conducted through chromatography techniques, and ten samples (S1-S10) were isolated. The samples were further subjected to NMR-Spectrometry analysis for elucidation and characterization of isolated compounds, and S1, S7, S9, S10 were final compounds. RAW 264.7 cells were again treated with the four compounds and results indicated absence of NO production, the opposite of the two previous outcomes where there was clear evidence of immunomodulation. The results obtained from the compounds has indicated that drugs work in synergy, and in combination, like TB treatment which is taken as combination of all drugs. We therefore conclude that indeed Sanicula immunomodulated RAW264.7 macrophages, and we present a strong observation of macrophage polarization from M0 phenotype to M1 phenotype which is capable of degrading and destroying Mycobacterium, and the antioxidant activity of the crude extracts of this medicinal plant. We therefore recommend further studies in the animal disease model. , Thesis (D.Ed) -- Faculty of Medicine and Health Sciences, 2023
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- Date Issued: 2023-12
Sediment characteristics and hydrodynamic conditions of the Swartkops estuary, Eastern Cape Province of South Africa
- Authors: Best, Lutho https://orcid.org/0000-0001-6400-9061
- Date: 2021-11
- Subjects: Geology, Stratigraphic , Estuarine oceanography , Swartkops River Estuary (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22611 , vital:52596
- Description: This study is a part of an environmental research project aimed at providing assessment information to the grain-size distribution, mineral compositions, sedimentary structures and coastal erosion and rehabilitation methods along the Swartkops estuary, a recent developing industry area of South Africa. The methodologies used in this study comprise desk study of literature, field geological investigation and sampling, and laboratory analyses including grainsize analysis, thin section microscope study, XRD mineral composition study and SEM-EDX grain surface texture and composition analyses.The basement and surrounding areas of the Swartkops estuary consist of three formations: the Enon Formation of mainly conglomerate, the Kirkwood Formation of sandstone and mudstone, and the Sundays River Formation of dominantly mudstone with sandstone, which integrated as Uitenhage Group of Cretaceous sequence with modern estuarine sand and alluvial sediments filled in the entire basin. Grain size analysis is a useful tool to assess hydrodynamic environments. The grain size parameters showed that most of the Swartkops estuary sediments are moderately sorted with very few well and poorly sorted, coarse to fine skewed in grain size distribution.Whereas the Bluewater Bay beach sediments are mostly fine grained, well sorted, fine to coarse skewed in grain size distribution. The bivariate scatter plots are an indication of shallow marine environment by beach and coastal processes with the influence of water flow and wind influence during transportation and deposition processes. Mineralogy studies revealed that the Swartkops estuary sediments are dominantly composed of minerals such as: quartz, calcite, feldspar (orthoclase and plagioclase), aragonite, clay minerals (smectite and illite), and salts such as NaCl and MgCl2. Skeletal carbonate minerals (shell fragments) are more than chemical precipitated carbonate minerals. Quartz is the most abundant detrital mineral observed in all the sediments and it comes from inland and transported into the estuary and the beach by fluvial streams, whereas skeletal calcite/aragonite is the most abundant biogenic carbonate derived from sea side and transported by marine currents. The study shows that grain surface textures reveal the existence of several features that reflect the depositional environments. Observed grain surface textures by microscope and SEM include V-shape pits, upturned pits caused by mechanical crashing and corrosion during transportation; crystalline precipitation of calcite, quartz, salt and clay by chemical precipitation and crystallization; dissolution pits and pores formed by dissolution, and burrow and boring by biogenetic activities. The grain surface morphologies are closely linked to different formation mechanisms and depositional environments. Well-developed sedimentary structures have been found in the beach and estuary, including sand dune, sand ridge, straight and sinuous ripple, ripple marks, aeolian nail marks, high angle tabular cross bedding, antidune, rill mark, rhomboid mark, swash line, mud crack, gravel pavement, interfering ripples, flat topped ripple mark, linguiod mark, asymmetric sinuous ripples, dendritic pattern on sandy beach, boring and bioturbation, burrows desiccation cracks and water escape hole. Different sedimentary structures are reflective of different hydrodynamic conditions and depositional environments. Coastal erosion is a major problem for damage of road, bridge and properties in the industrial areas in Swartkops, which is also a task for this study. The author had suggested some practical mitigation-methods to local government, such as groins, revetments, shoreline hardening, planting of vegetation, and vertical walls, bulkheads, sills, which could be useful for the protection of coastal erosion. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-11
The relationship between economic dependency and the reporting behaviours of victims of intimate partner violence: a case study of Bothaville in the Free State Province
- Authors: Mwatsiya, Innocent https://orcid.org/0000-0002-2845-5512
- Date: 2015-06
- Subjects: Wife abuse , Abused women
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24761 , vital:63549
- Description: This research study explored the relationship between economic dependency and the reporting behaviours of victims of intimate partner violence. The study was conducted using qualitative methods. Data was gathered using semi-structured interviews and a focus group discussion. Data analysis was done using thematic analysis where themes were allowed to emerge from the raw data findings. The study intended to explore the experiences; reporting behaviours; coping strategies and available sources of support for victims of intimate partner violence. The study drew mainly from literature and the tenets of the Resource Theory as well as the Learned Helplessness Theory. The study established that economic dependency supported the existence of intimate partner violence owing to the fact that victims of intimate partner violence feared financial vulnerability should they report the perpetrator resulting in his arrest. It was also established that the relationship between economic dependency and the reporting behaviours of victims of intimate partner violence was compounded by the number of children the victim had including the number of family members dependent on the victims besides her own children. More dependents were linked to a lesser likelihood of reporting intimate partner violence. This was due to the fact that more dependents translated into a greater financial burden in the absence of the source of income; the perpetrator. On the other hand, the study also established that even those victims who were employed, though earning lesser money than their partners (the perpetrators), did not leave abusive relationships. This was linked to the possibility of learned helplessness as well as the possibility of their individual incomes being too little to afford them a life away from the perpetrator. The study also established that victims of intimate partner violence experienced physical violence more than all other forms of violence. Availability of support, frequency and severity of abuse were identified as determinants of the timing for reporting. The study established that families were the most active sources of social support for victims of intimate partner violence whilst all professional networks of support were discovered to be functional. The study made several following recommendations including awareness raising, introduction of policy amendments and the inclusion of victims of intimate partner violence in income generating projects. Lastly the study concluded that little has been done and much needs to be done regarding the alleviation of the conditions of victims of intimate partner violence across the divide. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2015
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- Date Issued: 2015-06