An investigation into the antimicrobial and anticancer activities of Geranium incanum, Artemisia afra and Artemisia absinthium
- Authors: Freidberg, Ryno
- Date: 2009
- Subjects: Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10122 , http://hdl.handle.net/10948/1045 , Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Description: It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 μg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.
- Full Text:
- Date Issued: 2009
- Authors: Freidberg, Ryno
- Date: 2009
- Subjects: Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10122 , http://hdl.handle.net/10948/1045 , Medicinal plants -- South Africa , Cancer -- Alternative treatment -- South Africa , Anti-infective agents
- Description: It has been estimated that between 3000 and 4000 plant species are used for their medicinal properties throughout South Africa, with approximately 27 million South Africans making use of traditional medicines. Of this 27 million, 3 million South Africans rely on traditional medicine as their primary source of health care. Of the 250 000 to 500 000 known plant species, very few have been investigated for their pharmacological qualities, and compounds of significant medicinal value may still remain undiscovered in many plant species. The aims of this study included investigating the antimicrobial properties of Geranium incanum and Artemisia afra, both plants traditionally used for their medicinal properties, and comparing the antimicrobial activity of the latter to that of Artemisia absinthium, as well as investigating the anticancer properties of G. incanum and A. afra, and comparing the anticancer activity of the latter to that of A. absinthium. Infusions, aqueous-, methanol- and acetone extracts of the three plants were prepared and used for anticancer and antimicrobial screening. Plant specimens used to prepare extracts for antimicrobial activity were collected and extracted over three seasons, while extracts used for anticancer screening were prepared from plants collected during the summer only. Considerable variation existed in the percentage crude extract yields obtained when different extractants were used, while the season in which the plants were harvested and extracted also appeared to play a significant role in the amount of extract obtained. The plant extracts were screened for antimicrobial activity against various strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus and Bacillus cereus, using an agar dilution method. G. incanum and A. afra possessed activity for C. albicans, while all three plants showed activity for S. aureus and B. cereus. Activity was largely dependent on the extraction method used. iii The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was used to screen for anticancer activity of the respective extracts, at varying concentrations, against MCF-7 (human breast adenocarcinoma) cells, HT-29 (human colonic adenocarcinoma) cells and HeLa (human cervical cancer) cells. All of the extracts showed cytotoxic activity in all three cell lines to varying extents, depending on the extract used and cell line screened. The acetone extract of A. afra proved to be the most effective inhibitor with the lowest IC50 (2.65 ± 1.05 μg/ml) having been shown in MCF-7 cells. A. afra and A. absinthium showed similar inhibitory patterns, with the methanol- and acetone extracts having been the most potent inhibitors of each of the respective cell lines in general. Fluorescence microscopy employing 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and propidium iodide (PI) staining indicated that the acetone extract of A. afra induces apoptosis in MCF-7 cells as apposed to necrosis, and the results were comparable to those obtained for cells exposed to cisplatin. Screening of the A. afra acetone extract for toxicity in normal human cells using the CellTiter-Blue® assay indicated the extract to be toxic to peripheral blood mononuclear cells (PBMC’s) at concentrations comparable to that for MCF-7 cells, while cell cycle analysis of MCF-7 cells exposed to the A. afra acetone extract indicated the extract’s ability to induce apoptosis comparable to that of cisplatin, with the extract exerting its activity at a point during or just prior to the S phase of the cell cycle.
- Full Text:
- Date Issued: 2009
Antimicrobial activities of three medicinal plants against selected diarrheagenic pathogens
- Authors: Nkosi, Themba Johan
- Date: 2013
- Subjects: Anti-infective agents , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10126 , http://hdl.handle.net/10948/d1020759
- Description: Diarrhea is a global concern that the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO), have confirmed to be the second major cause of death in children under the age of five. Major bacterial pathogens that cause diarrhea include Escherichia coli, Salmonella species, Shigella species and Staphylococcus aureus. Antibiotic therapy is recommended depending on the severity and presentation of the disease; however, the appearance of antibiotic-resistant bacteria is an emerging global threat to the ability to treat these bacterial infections. This situation could be overcome by the discovery of new natural antibiotics. Plants have been a source of medicine for centuries and have been used to treat diseases including diarrhea. This makes plants a natural potential target to study for their antibiotic properties. The objective of this study was to determine the antibiotic properties of medicinal plants against known pathogens that cause bacterial diarrhea. Three medicinal plants, Cassia abbreviata, Kigelia africana, and Geranium incanum were investigated for their antimicrobial properties against these strains of microorganisms: American Type Culture Collection (ATTC) and Clinical Strains (CS). The plant materials were ground into powder, which was then dissolved in methanol, acetone and distilled water to extract the active compounds. The plant extracts were then used to (i) determine their antibiotic activity, (ii) determine the minimum inhibitory concentration (MICs), (iii) analyze the thin layer chromatography (TLC) fingerprints, and (iv) analyze the autobiography assay. The results obtained in this study met the aim and objectives of this study. The antimicrobial activities of the selected plants were obtained as discussed in Chapter 2 and 3. These results indicated that the traditional plants could be used as antimicrobials. In the screening assays, the test microorganisms were inhibited by the plant extracts, when they were subjected to plant extracts. This was performed on Mueller Hinton agar as sensitivity testing, which revealed clear zones of inhibition. The MIC values for each plant extract were established which ranged from 0.101 to 13.3 mg/dl. The TLC analysis revealed the spots which contained the active compounds which inhibited the bacterial growth. A bioautography assay was performed on the TLC plates, which exposed the exact spots containing the active compound inhibiting the bacteria. These results are clearly consistent with what former scientists have observed. Detailed explanations on the results are in Chapter 3 and 4 of this paper. It is important to note that all the procedures performed in this study were in vitro assays. Some effective in vitro assay activity may not always result in the same effective in vivo activity, because some active compounds may be metabolized and degraded into inactive metabolites. For this reason, the in vitro results obtained in this study, may not reflect the true effectiveness of the compounds in in vivo trials. It is therefore advised that future scientists should take a step further in analyzing the plant extracts through in vivo assays. Further testing and study on these plants at an advanced molecular level will be beneficial in the medical fields in the search for new antibiotics to treat infectious diseases. Purification and further analysis of their products can be helpful in the production of pure natural medicines. This will discover the active ingredients and compounds responsible for inhibition of the microorganisms. This will make the compounds potential candidates for a scientific validation and analysis for future scientists to bring a new dawn in the fight against infectious diseases.
- Full Text:
- Date Issued: 2013
- Authors: Nkosi, Themba Johan
- Date: 2013
- Subjects: Anti-infective agents , Drug resistance in microorganisms , Materia medica, Vegetable
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10126 , http://hdl.handle.net/10948/d1020759
- Description: Diarrhea is a global concern that the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO), have confirmed to be the second major cause of death in children under the age of five. Major bacterial pathogens that cause diarrhea include Escherichia coli, Salmonella species, Shigella species and Staphylococcus aureus. Antibiotic therapy is recommended depending on the severity and presentation of the disease; however, the appearance of antibiotic-resistant bacteria is an emerging global threat to the ability to treat these bacterial infections. This situation could be overcome by the discovery of new natural antibiotics. Plants have been a source of medicine for centuries and have been used to treat diseases including diarrhea. This makes plants a natural potential target to study for their antibiotic properties. The objective of this study was to determine the antibiotic properties of medicinal plants against known pathogens that cause bacterial diarrhea. Three medicinal plants, Cassia abbreviata, Kigelia africana, and Geranium incanum were investigated for their antimicrobial properties against these strains of microorganisms: American Type Culture Collection (ATTC) and Clinical Strains (CS). The plant materials were ground into powder, which was then dissolved in methanol, acetone and distilled water to extract the active compounds. The plant extracts were then used to (i) determine their antibiotic activity, (ii) determine the minimum inhibitory concentration (MICs), (iii) analyze the thin layer chromatography (TLC) fingerprints, and (iv) analyze the autobiography assay. The results obtained in this study met the aim and objectives of this study. The antimicrobial activities of the selected plants were obtained as discussed in Chapter 2 and 3. These results indicated that the traditional plants could be used as antimicrobials. In the screening assays, the test microorganisms were inhibited by the plant extracts, when they were subjected to plant extracts. This was performed on Mueller Hinton agar as sensitivity testing, which revealed clear zones of inhibition. The MIC values for each plant extract were established which ranged from 0.101 to 13.3 mg/dl. The TLC analysis revealed the spots which contained the active compounds which inhibited the bacterial growth. A bioautography assay was performed on the TLC plates, which exposed the exact spots containing the active compound inhibiting the bacteria. These results are clearly consistent with what former scientists have observed. Detailed explanations on the results are in Chapter 3 and 4 of this paper. It is important to note that all the procedures performed in this study were in vitro assays. Some effective in vitro assay activity may not always result in the same effective in vivo activity, because some active compounds may be metabolized and degraded into inactive metabolites. For this reason, the in vitro results obtained in this study, may not reflect the true effectiveness of the compounds in in vivo trials. It is therefore advised that future scientists should take a step further in analyzing the plant extracts through in vivo assays. Further testing and study on these plants at an advanced molecular level will be beneficial in the medical fields in the search for new antibiotics to treat infectious diseases. Purification and further analysis of their products can be helpful in the production of pure natural medicines. This will discover the active ingredients and compounds responsible for inhibition of the microorganisms. This will make the compounds potential candidates for a scientific validation and analysis for future scientists to bring a new dawn in the fight against infectious diseases.
- Full Text:
- Date Issued: 2013
Antimicrobial activity of selected plants and their combined preparations against pathogens causing respiratory infections
- Authors: Onyebuchi, Ukwuoma Collins
- Date: 2017
- Subjects: Anti-infective agents , Respiratory infections -- Alternative treatment
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/21197 , vital:29455
- Description: Bacterial infection of the respiratory system is one of the leading causes of death in the world’s population, killing over four million people annually. Treatment of respiratory infections is usually by antibiotics administration. The emergence of multi-drug-resistant pathogens has led to the search for more effective therapeutic agents especially from medicinal plants, as compounds from plants have been shown to possess some therapeutic potential. The aim of this study is to determine the antimicrobial activity of three plants, Tetradenia riparia, Leonotis leonurus and Salvia africana-lutea and the activity of their various combined preparations against 27 pathogens usually associated with respiratory ailments. Various solvents were used for extraction of the dried powdered plant materials. The agar disc diffusion antimicrobial assay and the micro-dilution assay methods were used to determine the inhibitory activity and the minimum inhibitory concentration of the plant extracts. The nature of phytochemicals present in the extracts was determined by thin layer chromatography. The results obtained in this study, showed that ethanol produced the highest average extract yield in both the individual and combined plant preparations. A two-way analysis of variance for the disc diffusion assay showed no significant difference in the inhibition zones (Appendix 1 and 2). MIC of 0.8 mg/ml was obtained with S. africana-lutea against S. pneumoniae ATCC 49619 and B. cereus ATCC 10976 strains, indicating a strong antibacterial activity. Synergistic interaction (FIC index ranging from 0.20 – 0.50) and a strong antimicrobial activity (MIC values ranging from 0.4 – 0.8 mg/ml), was obtained with the acetone extract of the 1:1 combination of L. leonurus with S. africana-lutea. The XEA and CEF solvent systems eluted the most number of compound spots and produced the best separations. The results obtained in this study validate the traditional use of these plants and their combinations for the treatment of respiratory ailments.
- Full Text:
- Date Issued: 2017
- Authors: Onyebuchi, Ukwuoma Collins
- Date: 2017
- Subjects: Anti-infective agents , Respiratory infections -- Alternative treatment
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: http://hdl.handle.net/10948/21197 , vital:29455
- Description: Bacterial infection of the respiratory system is one of the leading causes of death in the world’s population, killing over four million people annually. Treatment of respiratory infections is usually by antibiotics administration. The emergence of multi-drug-resistant pathogens has led to the search for more effective therapeutic agents especially from medicinal plants, as compounds from plants have been shown to possess some therapeutic potential. The aim of this study is to determine the antimicrobial activity of three plants, Tetradenia riparia, Leonotis leonurus and Salvia africana-lutea and the activity of their various combined preparations against 27 pathogens usually associated with respiratory ailments. Various solvents were used for extraction of the dried powdered plant materials. The agar disc diffusion antimicrobial assay and the micro-dilution assay methods were used to determine the inhibitory activity and the minimum inhibitory concentration of the plant extracts. The nature of phytochemicals present in the extracts was determined by thin layer chromatography. The results obtained in this study, showed that ethanol produced the highest average extract yield in both the individual and combined plant preparations. A two-way analysis of variance for the disc diffusion assay showed no significant difference in the inhibition zones (Appendix 1 and 2). MIC of 0.8 mg/ml was obtained with S. africana-lutea against S. pneumoniae ATCC 49619 and B. cereus ATCC 10976 strains, indicating a strong antibacterial activity. Synergistic interaction (FIC index ranging from 0.20 – 0.50) and a strong antimicrobial activity (MIC values ranging from 0.4 – 0.8 mg/ml), was obtained with the acetone extract of the 1:1 combination of L. leonurus with S. africana-lutea. The XEA and CEF solvent systems eluted the most number of compound spots and produced the best separations. The results obtained in this study validate the traditional use of these plants and their combinations for the treatment of respiratory ailments.
- Full Text:
- Date Issued: 2017
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