Anti-oxidant and cytotoxicity activity against the HCC70 Breast cancer cell line of aqueous and methanolic extracts of two red algae species from the Eastern Cape Coast, South Africa
- Authors: Basera, Afra Tsitsi
- Date: 2021
- Subjects: Drug resistance in cancer cells , Oxidative stress
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22589 , vital:52586
- Description: Cancer, despite extensive research, remains one of the leading causes of mortality. Research into plant-derived compounds has gained traction, as some are not cytotoxic towards healthy cells and pose fewer side effects. Marine algae produce secondary metabolites, protecting them from oxidative stress, which causes cardiovascular diseases, cancer, and diabetes. Therefore, this study aimed to evaluate the anticancer potential of selected red algae species, collected from Humewood Beach, Gqeberha in South Africa, against HCC70 (human breast adenocarcinoma) cancer cells. Identification of the species was made through DNA barcoding of the rbcL gene. Methanolic and aqueous extracts of Gelidium pristoides and Laurencia natalensis were evaluated for antioxidant activity, phytochemical content, and anticancer potential. The phytochemical composition was determined using the phenol, flavonoid, flavonol, tannin, and proanthocyanidin content assays. Antioxidant potential was evaluated using the Ferric reducing antioxidant potential, Diphenyl-1- Picrylhydrazyl (DPPH), nitric oxide, 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity, and total antioxidant capacity (TAC) assays. The resazurin assay was used to determine the antiproliferative and cytotoxic activity of the methanolic extracts and solid-phase extraction fractions against the HCC70 breast cancer cells. The red algae species were identified as G. pristoides and L. natalensis. The aqueous extract of G. pristoides exhibited significantly higher phenols (24.0 mg/g GAE), tannins (31.6 mg/g TAE), and flavonols content (20.5 mg/g RE) than its methanolic extract, or the aqueous and methanolic extracts of L. natalensis. Methanolic extracts of G. pristoides and L. natalensis exhibited significantly higher proanthocyanidin contents (19.4 mg/g and 15.7 mg/g CE) than their respective aqueous extracts (13.0 mg/g and 11.8 mg/g CE). Flavonoids, however, were absent in both species. The aqueous and methanol extracts of Laurencia natalensis and Gelidium pristoides exhibited low inhibitory activities (less than 50%) against DPPH, ABTS, and nitric oxide radicals. Both species also showed low ferric reducing power. All the extracts were antiproliferative and cytotoxic against the HCC70 breast cancer cells, with L. natalensis exhibiting more significant inhibitory activity. However, its Solid Phase Extraction fractions did not display antiproliferative potential, unlike fraction 4 of G. pristoides. The study results suggest that both G. pristoides and L. natalensis possess bioactive compounds with potential anticancer activity. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
- Full Text:
The perception of police officers towards corruption in South African police services: a case study of Polokwane cluster policing area in Limpopo Province
- Authors: Rathogwa, Emmah Mufanadzo
- Date: 2021
- Subjects: Corruption , Police corruption , Police misconduct
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/27314 , vital:66935
- Description: The 1996 National Crime Prevention Strategy identified corruption within the criminal justice sector as the greatest threat to the governance of security. Police corruption has been a huge obstacle within the South African Police Service’s endeavours to tackle improper activities of police officers. A general definition of corruption is “use of public office for private gain”; this includes bribery and extortion, which involves at least two parties, and other types of malfeasance that a public official can carry out alone, including fraud and embezzlement. The corruption of police officers impinges on the capacity and ability of the entire force in ensuring that all citizens abide by the law. This study explored the perceptions of police officers towards corruption activities in South African Police Services (SAPS) within the Polokwane Cluster (Capricorn District) Policing Area in Limpopo province. In this study, a qualitative research design was used. The researcher used purposive sampling to select participants. For collection of data, semi-structured interviews were used where the researcher interviewed police officers within the Polokwane Cluster Capricorn District Policing Area. The researcher conducted fifty 50 interviews with five police officers from 10 police stations within the Polokwane Cluster Capricorn District Policing Area, namely: Botlokwa, Lebowakgomo, Polokwane,Westernburg, Seshego, Mankweng, Mashashane, Matlala, Mogwadi and Zebediela police stations. In addition, secondary sources were used where the researcher relied on documents from the Independent Police Investigations IPID on statistics on police corruption, among other scales of measurements. For the analysis of data, thematic content analysis was used to analyse the data collected through interviews whilst document analysis was used for analysing data collected from secondary sources. The findings gathered in this study revealed that police corruption is widespread within the Polokwane Cluster Capricorn District Policing Area in Limpopo province due some police officers’ fear of victimisation of their families or loved ones if they expose corrupt acts by other police officers. Furthermore, corruption of the South African Police Services personnel has been reported where potential police recruits are required to pay bribes for them to be placed for the job. Weak leadership within the South African police service and poor policy formulation and implementation have been identified by participants to be some of the main determinants of corruption within the South African Police Services. As a recommendation to counter the adverse effects of police corruption, a number of strategies have been formulated in this study such as the establishment of vibrant anticorruption mechanisms. It is essential for the government to recall passionate former police officials to investigate all the corrupt officials. The South African government should establish a very sophisticated anti-corruption body independent from the SAPS to spearhead the strategy to combat corruption. The recruitment of police personnel should culminate into hiring individuals who would see the police job as a calling and do it passionately. They should firstly target people who choose police related courses are already studying courses in crime investigation from grassroots level. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2021
- Full Text: