Traore, A. N.Potgieter, N.Tshisikhawe, P.Ajmal, Antoinette Alliya2019-06-052019-06-052019-05Ajmal, Antoinette Alliya (2019) Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria, University of Venda, South Africa.<http://hdl.handle.net/11602/1345>.http://hdl.handle.net/11602/1345MSc (Microbiology)Department of MicrobiologyBackground: The high on-going incidences of infectious diseases, specifically those caused by multi-drug resistant bacteria in the last decade has made it a necessity to investigate a variety of antimicrobial drug sources, such as plants. Medicinal plants have played a significant role in drug discovery for western pharmaceuticals recently and have also been used successfully by traditional healers and herbalists to treat various infectious diseases for centuries. Currently, a few medicinal plants are commercialized, reason being most medicinal plants phytochemicals have not been studied yet, although they have been traditionally used by healers. Due to the constant development of multi-drug resistance of bacteria to antibiotics, S. africana extracts can provide an opportunity to finding new antibacterial compounds that can be used as the foundation for formulating new antimicrobial drugs. Objectives: The aim of this study was to screen antibacterial activity of the crude extract and fractions of S. africana against multi-drug resistant bacteria and to also evaluate other biological properties. Methods: Preliminary screening of phytochemical constituents of S. africana and fractions was done using standard qualitative and quantitative methods. Antibacterial activity of the extracts was evaluated using the agar well diffusion method and the microdilution assay against MDR bacterial strains. Antioxidant activities of the MCE and its fractions were measured by DPPH and reducing power assays, and the toxicity of the MCE and its fractions was tested on Vero cells using Cell-based high content screening assay. Results: Phytochemical analysis of the MCE and fractions obtained in this study showed the presence of phenolics, flavonoids, alkaloids, steroids, saponins, cardiac glycosides and terpenoids in most of S. african’s test samples. Fraction F1 and F2 both lacked alkaloids and saponins. The micro-plate dilution assay demonstrated that the MCE and all its fractions can inhibit the growth of all selected MDR bacterial strains tested against at different concentrations (0.1mg/ml to >12.5mg/ml), wherein the lowest MIC averages were obtained from fractions F3 and F6, with 0.59 mg/ml and 0.71 mg/ml MIC averages respectively. Contrary to the micro-plate dilution assay, the well diffusion assay demonstrated that MCE and all its fractions were not active against all the selected MDR bacterial strains tested against, as no inhibition was shown against the growth of K. pneumonia by any of S. african’s test samples. For DPPH assay, the IC50 of S. african’s test samples ranged between 0.01 ±0.34 mg/ml to 0.62 ± 0.05 mg/ml, whiles for the reducing power assay, EC50 measured ranged between 0.61 ± 0.01 mg/ml and 11.30 ± 0.04 mg/ml. The MCE and fraction F2 exhibited the highest toxicity to Vero cells. Conclusion: The MCE and fractions of the plant S. africana have antibacterial activity against MDR bacterial strains, beneficial biological properties and contains potential antibacterial compounds that may be valuable in the discovery of new potential drugs for treatment of infectious diseases1 online resource (xiii, 86 leaves : color illustrations, color maps)enUniversity of VendaAntibacterial activityUCTDMulti-drug resistants bacteriaSpirostachys africana579.34096825Euphorbiaceae -- South Africa -- LimpopoEnterobactriaceae -- South Africa -- LimpopoGram -negative bacteria -- South Africa -- LimpopoDrug resistance in microbiologyAntibiotics -- South Africa -- LimpopoMedicinal plants -- South Africa -- LimpopoDissertationAjmal AA. Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria. []. , 2019 [cited yyyy month dd]. Available from: http://hdl.handle.net/11602/1345Ajmal, A. A. (2019). <i>Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria</i>. (). . Retrieved from http://hdl.handle.net/11602/1345Ajmal, Antoinette Alliya. <i>"Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria."</i> ., , 2019. http://hdl.handle.net/11602/1345TY - Dissertation AU - Ajmal, Antoinette Alliya AB - Background: The high on-going incidences of infectious diseases, specifically those caused by multi-drug resistant bacteria in the last decade has made it a necessity to investigate a variety of antimicrobial drug sources, such as plants. Medicinal plants have played a significant role in drug discovery for western pharmaceuticals recently and have also been used successfully by traditional healers and herbalists to treat various infectious diseases for centuries. Currently, a few medicinal plants are commercialized, reason being most medicinal plants phytochemicals have not been studied yet, although they have been traditionally used by healers. Due to the constant development of multi-drug resistance of bacteria to antibiotics, S. africana extracts can provide an opportunity to finding new antibacterial compounds that can be used as the foundation for formulating new antimicrobial drugs. Objectives: The aim of this study was to screen antibacterial activity of the crude extract and fractions of S. africana against multi-drug resistant bacteria and to also evaluate other biological properties. Methods: Preliminary screening of phytochemical constituents of S. africana and fractions was done using standard qualitative and quantitative methods. Antibacterial activity of the extracts was evaluated using the agar well diffusion method and the microdilution assay against MDR bacterial strains. Antioxidant activities of the MCE and its fractions were measured by DPPH and reducing power assays, and the toxicity of the MCE and its fractions was tested on Vero cells using Cell-based high content screening assay. Results: Phytochemical analysis of the MCE and fractions obtained in this study showed the presence of phenolics, flavonoids, alkaloids, steroids, saponins, cardiac glycosides and terpenoids in most of S. african’s test samples. Fraction F1 and F2 both lacked alkaloids and saponins. The micro-plate dilution assay demonstrated that the MCE and all its fractions can inhibit the growth of all selected MDR bacterial strains tested against at different concentrations (0.1mg/ml to >12.5mg/ml), wherein the lowest MIC averages were obtained from fractions F3 and F6, with 0.59 mg/ml and 0.71 mg/ml MIC averages respectively. Contrary to the micro-plate dilution assay, the well diffusion assay demonstrated that MCE and all its fractions were not active against all the selected MDR bacterial strains tested against, as no inhibition was shown against the growth of K. pneumonia by any of S. african’s test samples. For DPPH assay, the IC50 of S. african’s test samples ranged between 0.01 ±0.34 mg/ml to 0.62 ± 0.05 mg/ml, whiles for the reducing power assay, EC50 measured ranged between 0.61 ± 0.01 mg/ml and 11.30 ± 0.04 mg/ml. The MCE and fraction F2 exhibited the highest toxicity to Vero cells. Conclusion: The MCE and fractions of the plant S. africana have antibacterial activity against MDR bacterial strains, beneficial biological properties and contains potential antibacterial compounds that may be valuable in the discovery of new potential drugs for treatment of infectious diseases DA - 2019-05 DB - ResearchSpace DP - Univen KW - Antibacterial activity KW - Multi-drug resistants bacteria KW - Spirostachys africana LK - https://univendspace.univen.ac.za PY - 2019 T1 - Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria TI - Antibacterial activity of the crude extract and fractions of spirostachys africana against multi-drug resistant bacteria UR - http://hdl.handle.net/11602/1345 ER -