An investigation into the impact of geographical location on the phytochemical composition, pharmacological and toxicological activities of Tulbaghia violacea collected from the Eastern Cape and Gauteng Province
- Authors: Kader, Tasmeera
- Date: 2024-10-11
- Subjects: Tulbaghia violacea , Phytochemicals , Alliaceae Geographical distribution , Diabetes , Alzheimer's disease
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/461819 , vital:76242
- Description: Introduction: The number of communicable and non-communicable diseases continues to rise and has become more prevalent. While drugs exist to manage and/ or treat majority of the communicable and non-communicable diseases, the rise in disease prevalence puts pressure on researchers to find new drug molecules to treat and manage these ailments. Traditional medicine refers to the knowledge, skills and practices which are based on the beliefs and experiences indigenous to cultures and is used to maintain health. Most of the research into traditional medicine focuses on the medicinal plants used. Medicinal plants are any plants in which one or more of its organs contain substances which are used for therapeutic purposes or for the synthesis of drugs. Tulbaghia violacea is a monocotyledonous genus of herbaceous perennial bulbs which is native to Africa and can be readily found throughout South Africa. It is popular for its antimicrobial, antifungal, anticoagulant, antioxidant and anticancer properties. It has been that ecological factors influence the composition and quantity of phytochemicals present in a plant. Aim of the study: The aim of the study was to investigate the impact of geographical location on the phytochemical composition, pharmacological and toxicological activities of T. violacea collected from the Eastern Cape and Gauteng Province. Methods: The leaves of T. violacea were collected from the Eastern Cape and Gauteng Province. The leaves were dried and extracted using serial maceration with solvents hexane, acetone and methanol. The resulting extracts were subjected to qualitative preliminary phytochemical analysis and a quantitative total phenol content test was carried out using gallic acid as the standard. Thin layer chromatography (TLC) was performed to identify classes of compounds present in T. violacea. xix Antioxidant activity of T. violacea was determined qualitatively using a dot-plot and quantitatively using a DPPH radical scavenging activity assay. Ascorbic acid was used as the standard. Anti-diabetic properties of T. violacea were assessed using an α- amylase inhibition assay and an α- glucosidase inhibition assay. Acarbose was used as the standard for these assays. The anti-Alzheimer properties of T. violacea leaf extracts was determined using and acetylcholinesterase (AChE) inhibition assay. Donepezil was used as the standard for this assay. The DPPH radical scavenging activity, the α- amylase inhibition assay, the α- glucosidase inhibition assay and the AChE inhibition assay was combined with linear regression to determine the IC50 values of the T. violacea extracts and the standards. Statistical analysis was conducted to determine any differences between the plant samples and the standards as well as any differences between the EC and GP sample. Results: The results of the qualitative phytochemical analysis revealed the presence of saponins, flavonoids, tannins, alkaloids, steroids, cardiac glycosides and phenolic compounds present in T. violacea collected from EC and GP. However, their presence in the samples were different based on where the plant was cultivated. The results of the total phenolic content test, revealed that the hexane, acetone and methanol extracts of T. violacea contained phenolic compounds with the highest quantity of phenolic compounds being present in the methanol extracts. Significant statistical difference in total phenolic content between the EC and GP samples were seen for the hexane and methanol extracts. The results of the TLC revealed the presence of multiple bands which confirmed the presence of multiple phytochemicals in T. violacea. All of the extracts of T. violacea from EC and GP, showed antioxidant activity using both the dot-plot and the DPPH radical scavenging activity assay. The highest DPPH radical scavenging activity was seen by the hexane extract of the EC sample of T. violacea. The results showed significant statistical difference between the DPPH radical scavenging activity of the EC and GP samples. , Thesis (Msc (Pharmacy)) -- Faculty of Pharmacy, Pharmacy, 2024
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- Date Issued: 2024-10-11
Evaluation of anti-diabetic activity of selected red marine macro-algae found along South African coastal areas
- Authors: Bambo, Karabo https://orcid.org/0000-0002-3721-2424
- Date: 2021-04
- Subjects: Marine algae , Phytochemicals
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22533 , vital:52405
- Description: Marine macro-algae are a good source of potential primary and secondary metabolites. Phytochemicals of the samples were extracted using methanol and water. This study evaluated the phytochemical constituents, antioxidant activity and antidiabetic activity of selected red marine macro-algae sampled from Gqeberha, South Africa. The species collected were identified as Gelidium pristoides, Scinaia furcellata and Portieria tripinita using DNA barcoding. Results showed the presence of several phytochemicals such as saponins, phenols, flavonols, tannins, proanthocyanidins and flavonoids. Methanol was a more effective polyphenol extraction solvent than water. Gelidium pristoides (H2O) was observed to contain the highest phenol and proanthocyanidin content, which correlated to Gelidium pristoides (H2O) having the greatest FRAP and DPPH radical scavenging activity IC50 at 0.227. Portieria tripinita (MeOH) extract had the greatest flavonoid content. Flavonol content was high for Scinaia furcellata while the highest tannin content was observed in both H2O and MeOH extracts of Gelidium pristoides. All the selected marine macro-algae species showed concentration-dependent reducing power. The extract with the highest ABTS scavenging activity was Gelidium pristoides (MeOH) IC50 at 0.227. Portieria tripinita was the only species that showed Nitric oxide scavenging activity, with (H2O) extract showing the highest activity IC50 at 3.052. Only MeOH extracts of Gelidium pristoides and Scinaia furcellata showed very slight α-amylase inhibition, however, all extracts successfully inhibited the activity of α-glucosidase with the exception of the H2O extracts of Scinaia furcellata. All crude extracts of Gelidium pristoides, Scinaia furcellata and Portieria tripinita showed no significant/weak effect on glucose uptake and utilization by C3A cells following 24 hours of treatment, with the exception of the aqueous extracts of Scinaia furcellata at the highest concentration of 100 μg/ml. The in-vitro MTT cytotoxicity assay revealed that only MeOH extracts of Gelidium pristoides and Scinaia furcellata had a 15 significant toxic effect on C3A hepatocytes at concentrations of 100 μg/ml and 25μg/ml, respectively. Portieria tripinita aqueous extract showed cytotoxicity when evaluated using Hoechst 33342/Propidium iodide (PI) dual staining. , Thesis (MSc) -- Faculty of Science and Agriculture, 2021
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- Date Issued: 2021-04