Comparison of in vitro activities of selected Ganoderma species in relation to skin diseases
- Authors: Van Aardt, Robin Kaylah
- Date: 2022-12
- Subjects: Ganoderma diseases of plants -- South Africa , Macrophages
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/61143 , vital:69766
- Description: Ganoderma species of macrofungi have been reported to have a multitude of medicinal properties, however, there is limited information on this genus in South Africa. The goal of this study was to compare biological activities of selected Ganoderma spp. in relation to skin diseases with emphasis on the antibacterial, antioxidant, anti-inflammatory and cytotoxic in vitro activities. Ethanolic and aqueous extracts prepared from six samples of G. lucidum [two commercial products (MG-LZ8 and Medi Mushroom Reishi extract), polar, antler, fruiting body and mycelium] and ten cultivated Ganoderma spp. were screened for bioactivities. Antibacterial activity was assessed using the 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium (INT) assay against skin pathogens (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae). Cytotoxicity was determined using bisBenzamide H 33342 trihydrochloride/propidium iodide (Hoechst/ PI) staining on the B16F10 melanoma cell line. The 2,2-Diphenyl-1- picrylhydrazyl (DPPH) and Ferric reducing ability of plasma (FRAP) assays were used to investigate antioxidant activity. Immune modulatory effects included detection of phagocytic activity and phenotypic changes of RAW 264.7 murine macrophage cells. The phenotypic macrophage polarisation of the extracts on RAW 264.7 murine macrophage cells was tested by treating the cells with the extracts and measuring the fluorescence of cell surface markers. CD86 was used as indicator for the M1 phenotype and CD206 as a general marker for M2 phenotypes. The commercially available and cultivated G. lucidum extracts did not show antibacterial activity within the 0-2mg/mL concentration range tested. The commercially available MG-LZ8 G. lucidum extract expressed cytotoxic activity with an IC50 value of 21.26 µg/mL while the ethanolic conk fruiting body and mycelial G. lucidum extract showed a significant reduction in live cells, indicating anti-proliferative activity. G. destructans mycelial ethanol extract displayed anti-proliferative activity at a concentration of 200 μg/mL which shows great potential as a mycelial extract. All the G. lucidum extracts exhibited free radical scavenging abilities with the Ganoderma spp. showing little to no measurable activity. G. lucidum and Ganoderma spp extracts had similar responses without inflammatory activity for the concentration ranges tested. The extracts did not increase macrophage phagocytic activity using the pHrodo™ Green E. coli iii BioParticles™ Conjugate. G. lucidum and Ganoderma spp. extracts induced macrophage polarisation toward the M2 phenotype, with the G. lucidum antler and conk fruiting body extracts displaying significant activity. This study illustrates one of the first investigations of the bioactivity of indigenous Ganoderma spp.; G. destructans type and G. eickeri, spp. nov. identified by Coeztee et al (2015). , Thesis (MSc) -- Faculty of Science, School of Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2022-12
- Authors: Van Aardt, Robin Kaylah
- Date: 2022-12
- Subjects: Ganoderma diseases of plants -- South Africa , Macrophages
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/61143 , vital:69766
- Description: Ganoderma species of macrofungi have been reported to have a multitude of medicinal properties, however, there is limited information on this genus in South Africa. The goal of this study was to compare biological activities of selected Ganoderma spp. in relation to skin diseases with emphasis on the antibacterial, antioxidant, anti-inflammatory and cytotoxic in vitro activities. Ethanolic and aqueous extracts prepared from six samples of G. lucidum [two commercial products (MG-LZ8 and Medi Mushroom Reishi extract), polar, antler, fruiting body and mycelium] and ten cultivated Ganoderma spp. were screened for bioactivities. Antibacterial activity was assessed using the 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium (INT) assay against skin pathogens (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae). Cytotoxicity was determined using bisBenzamide H 33342 trihydrochloride/propidium iodide (Hoechst/ PI) staining on the B16F10 melanoma cell line. The 2,2-Diphenyl-1- picrylhydrazyl (DPPH) and Ferric reducing ability of plasma (FRAP) assays were used to investigate antioxidant activity. Immune modulatory effects included detection of phagocytic activity and phenotypic changes of RAW 264.7 murine macrophage cells. The phenotypic macrophage polarisation of the extracts on RAW 264.7 murine macrophage cells was tested by treating the cells with the extracts and measuring the fluorescence of cell surface markers. CD86 was used as indicator for the M1 phenotype and CD206 as a general marker for M2 phenotypes. The commercially available and cultivated G. lucidum extracts did not show antibacterial activity within the 0-2mg/mL concentration range tested. The commercially available MG-LZ8 G. lucidum extract expressed cytotoxic activity with an IC50 value of 21.26 µg/mL while the ethanolic conk fruiting body and mycelial G. lucidum extract showed a significant reduction in live cells, indicating anti-proliferative activity. G. destructans mycelial ethanol extract displayed anti-proliferative activity at a concentration of 200 μg/mL which shows great potential as a mycelial extract. All the G. lucidum extracts exhibited free radical scavenging abilities with the Ganoderma spp. showing little to no measurable activity. G. lucidum and Ganoderma spp extracts had similar responses without inflammatory activity for the concentration ranges tested. The extracts did not increase macrophage phagocytic activity using the pHrodo™ Green E. coli iii BioParticles™ Conjugate. G. lucidum and Ganoderma spp. extracts induced macrophage polarisation toward the M2 phenotype, with the G. lucidum antler and conk fruiting body extracts displaying significant activity. This study illustrates one of the first investigations of the bioactivity of indigenous Ganoderma spp.; G. destructans type and G. eickeri, spp. nov. identified by Coeztee et al (2015). , Thesis (MSc) -- Faculty of Science, School of Biochemistry and Microbiology, 2023
- Full Text:
- Date Issued: 2022-12
Evolving IoT honeypots
- Authors: Genov, Todor Stanislavov
- Date: 2022-10-14
- Subjects: Internet of things , Malware (Computer software) , QEMU , Honeypot , Cowrie
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362819 , vital:65365
- Description: The Internet of Things (IoT) is the emerging world where arbitrary objects from our everyday lives gain basic computational and networking capabilities to become part of the Internet. Researchers are estimating between 25 and 35 billion devices will be part of Internet by 2022. Unlike conventional computers where one hardware platform (Intel x86) and three operating systems (Windows, Linux and OS X) dominate the market, the IoT landscape is far more heterogeneous. To meet the growth demand the number of The System-on-Chip (SoC) manufacturers has seen a corresponding exponential growth making embedded platforms based on ARM, MIPS or SH4 processors abundant. The pursuit for market share is further leading to a price war and cost-cutting ultimately resulting in cheap systems with limited hardware resources and capabilities. The frugality of IoT hardware has a domino effect. Due to resource constraints vendors are packaging devices with custom, stripped-down Linux-based firmwares optimized for performing the device’s primary function. Device management, monitoring and security features are by and far absent from IoT devices. This created an asymmetry favouring attackers and disadvantaging defenders. This research sets out to reduce the opacity and identify a viable strategy, tactics and tooling for gaining insight into the IoT threat landscape by leveraging honeypots to build and deploy an evolving world-wide Observatory, based on cloud platforms, to help with studying attacker behaviour and collecting IoT malware samples. The research produces useful tools and techniques for identifying behavioural differences between Medium-Interaction honeypots and real devices by replaying interactive attacker sessions collected from the Honeypot Network. The behavioural delta is used to evolve the Honeypot Network and improve its collection capabilities. Positive results are obtained with respect to effectiveness of the above technique. Findings by other researchers in the field are also replicated. The complete dataset and source code used for this research is made publicly available on the Open Science Framework website at https://osf.io/vkcrn/. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Genov, Todor Stanislavov
- Date: 2022-10-14
- Subjects: Internet of things , Malware (Computer software) , QEMU , Honeypot , Cowrie
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362819 , vital:65365
- Description: The Internet of Things (IoT) is the emerging world where arbitrary objects from our everyday lives gain basic computational and networking capabilities to become part of the Internet. Researchers are estimating between 25 and 35 billion devices will be part of Internet by 2022. Unlike conventional computers where one hardware platform (Intel x86) and three operating systems (Windows, Linux and OS X) dominate the market, the IoT landscape is far more heterogeneous. To meet the growth demand the number of The System-on-Chip (SoC) manufacturers has seen a corresponding exponential growth making embedded platforms based on ARM, MIPS or SH4 processors abundant. The pursuit for market share is further leading to a price war and cost-cutting ultimately resulting in cheap systems with limited hardware resources and capabilities. The frugality of IoT hardware has a domino effect. Due to resource constraints vendors are packaging devices with custom, stripped-down Linux-based firmwares optimized for performing the device’s primary function. Device management, monitoring and security features are by and far absent from IoT devices. This created an asymmetry favouring attackers and disadvantaging defenders. This research sets out to reduce the opacity and identify a viable strategy, tactics and tooling for gaining insight into the IoT threat landscape by leveraging honeypots to build and deploy an evolving world-wide Observatory, based on cloud platforms, to help with studying attacker behaviour and collecting IoT malware samples. The research produces useful tools and techniques for identifying behavioural differences between Medium-Interaction honeypots and real devices by replaying interactive attacker sessions collected from the Honeypot Network. The behavioural delta is used to evolve the Honeypot Network and improve its collection capabilities. Positive results are obtained with respect to effectiveness of the above technique. Findings by other researchers in the field are also replicated. The complete dataset and source code used for this research is made publicly available on the Open Science Framework website at https://osf.io/vkcrn/. , Thesis (MSc) -- Faculty of Science, Computer Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Along the river that flowed south
- Authors: Mohlomi, Teboho Samson
- Date: 2022-04-07
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/234195 , vital:50171
- Description: Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
- Authors: Mohlomi, Teboho Samson
- Date: 2022-04-07
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/234195 , vital:50171
- Description: Thesis (MA) -- Faculty of Humanities, School of Languages and Literatures, 2022
- Full Text:
- Date Issued: 2022-04-07
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