COPYRIGHT AND CITATION CONSIDERATIONS FOR THIS THESIS/ DISSERTATION o Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. o NonCommercial — You may not use the material for commercial purposes. o ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. How to cite this thesis Surname, Initial(s). (2012). Title of the thesis or dissertation (Doctoral Thesis / Master’s Dissertation). Johannesburg: University of Johannesburg. Available from: http://hdl.handle.net/102000/0002 (Accessed: 22 August 2017). A synopsis of medicinally important indigenous species of the genus Scabiosa (Caprifoliaceae), an evaluation of their biological activity and synergistic properties of Scabiosa columbaria By Ndinne Wendy Mugwena (201400888) Dissertation submitted in fulfilment of the requirements for the degree of Magister Scientiae (MSc) In Botany In the Faculty of Science at the University of Johannesburg South Africa Supervisor: Prof. A.N. Moteetee (UJ) Co-supervisor: Prof S. Van Vuuren (WITS) August 2020 DECLARATION I declare that this dissertation hereby submitted to the University of Johannesburg for the degree MAGISTER SCIENTIAE (Botany), is my own work and has not been previously submitted by me for a degree at another institution. Ndinne W. Mugwena (August 2020) i DEDICATION I dedicate this dissertation to my parents, Livhuwani & Aaron Mugwena as well as my grandmother Naume Nethanani “Momi” Ndi livhuwa thikhedzo ye vha mpha yone, na u kondelela havho u bva mathomoni u swika zwino. Ndi livhuwa zwihulwane u pfesesa ndila ye nda di nangela yone isingo doweleyaho. “Momi” thabelo dzavho ndi dzone dzi ntikaho misi yothe. My Omnipresent God of Grace, I thank You! Proverbs 16:3 “Ask the LORD to bless your plans, and you will be successful in carrying them out.” ii ACKNOWLEDGMENT I would like to express my gratitude to the following persons and institutions: . Prof Annah Moteetee, my supervisor, for the opportunity to learn under your supervision and guidance. I appreciate your patience, support and perseverance to complete this dissertation with me amid a pandemic. Prof Sandy Van Vuuren for co-supervising my study, together with your laboratory technician Phumzile Moerane for assisting with antimicrobial laboratory experience at University of Witwatersrand. Mr Thinus Fourie, for always being willing to assist with all my laboratory needs. Johnathan and the Random Harvest Nursery stuff, for helping me grow some of the plants that I needed. Dube Sifelani & Dance Mabu from the Department of Chemistry for assisting with antacid activity practical section . The University of Johannesburg and Department of Botany and Plant Biotechnology for the support. National Research Foundation (NRF) for their financial support during my studies. To my siblings, Nkhangweleni, Tshifhiwa, Ndivhuwo and Nanne, you have all been amazing cheerlearders. iii ABSTRACT The genus Scabiosa L., so called because of its traditional use for the treatment of scabies, belongs to the family Caprifoliaceae. This genus is relatively large comprising about 80 species distributed mainly in the Mediterranean, with only nine species occurring naturally in southern Africa. In southern Africa the genus was last revised by Harvey and Sonder (1865), however, the purpose of the current study was to provide a synopsis of the medicinally important species of the genus. In addition, the study aimed to record the ethnomedicinal uses of these species and identify the plants with which Scabiosa columbaria L. is used in combination. The third aim of the study was to evaluate S. columbaria and the plant combinations for antibacterial and anti-inflammatory activities and then assess interactive effects. The fourth aim was to evaluate S. columbaria for its antacid and acid neutralising potential and lastly, to investigate all the plants studied here for their toxicity levels. Herbarium specimens were examined to study the morphological characteristics and the geographical distribution patterns of the medicinal species. For the antibacterial activity, the minimum inhibitory concentration assay was used. The pathogens tested were Neisseria gonorrhoeae (sexual transmitted infections), Bacillus cereus, Enterococcus faecalis and Escherichia coli (gastrointestinal pathogens) and skin pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis). The anti-inflammatory activities were investigated through inhibition of the cyclooxygenase (COX) isoenzymes COX-1 and COX-2, as well as 15-lipoxygenase enzyme (15-LOX). Back titration of sodium hydroxide and Fordtran’s model were used to assess the antacid activities and neutralization potential of the selected plants. Lastly the brine shrimp lethality assay was used to test the toxicity of S. columbaria and plants used in combination. The results indicate that leaf morphology is of diagnostic importance in distinguishing the closely related taxa with differences observed in pubescence density, leaf shape, size and margins. Nine species of Scabiosa occur in southern African and four of these are used for medicinal purposes, namely: Scabiosa columbaria, S. transvaalensis S. Moore, S. incisa Mill., and S. albanensis R.A. Dyer. Scabiosa columbaria is sometimes mixed with other species, for example Afroaster hispida (Thunb.) J.C. Manning & Goldblatt., Cussonia paniculata subsp sinuata (Reyneke & Kok) iv De Winter., Dicoma anomala Sond., Helichrysum caespititium (DC.) Sond. Ex Harv., Searsia divaricata (Eckl. & Zeyh) Moffett., and Zantedeschia albomaculata (Hook). Baill. where it is used as a remedy for a wide variety of ailments ranging from heartburn to infections associated with the gastrointestinal system, respiratory tract, eyes, and the skin, as well as inflammatory diseases. Only S. columbaria has hitherto been assessed for its antibacterial activity against pathogens responsible for sexually transmitted and respiratory tract infections. Interestingly, although S. columbaria and plants used in combination with it, have been documented frequently in the literature for medicinal uses, their antibacterial screening showed no noteworthy activity against all the tested pathogens. Scabiosa columbaria was found to be non-toxic. However, extracts from two plants, i.e. C. paniculata subsp sinuata (organic and aqueous) and D. anomala (organic) used in combination with S. columbaria were found to be toxic. It was also noted that their presence in combination with S. columbaria increased the mortality rate of the brine shrimp. When the concentration was decreased, a drastic decrease in the mortality rate was observed. For anti-inflammatory activity, S. columbaria exhibited selective inhibition of COX-1, which is associated with negative side effects and showed moderate activity against 15-LOX. The combination of S. columbaria with C. paniculata subsp sinuata and S. divaricata had noteworthy anti-inflammatory activity, being able to inhibit both LOX and COX enzymes at low concentrations. For antacid activity, the immediate neutralization of artificial gastric juice was higher for the combinations when compared to S. columbaria used individually. When comparing the results of S. columbaria and the positive control (Rennie®) in the back titration protocol using both NaOH and artificial gastric juice, the results showed that the plant was a weak antacid when used individually and in combination with other plants. Although most of the results were not in support of the use of Scabiosa species in ethnomedicine, the species should not be neglected completely. Future studies should focus on understanding the behaviour of ethnomedicinally important Scabiosa sp when tested in complex environments. v TABLE OF CONTENTS DECLARATION ...........................................................................................................................i DEDICATION .............................................................................................................................. ii ACKNOWLEDGMENT ............................................................................................................... iii ABSTRACT ................................................................................................................................ iv TABLE OF CONTENTS ............................................................................................................. vi LIST OF FIGURES .................................................................................................................. viii LIST OF TABLES ....................................................................................................................... ix LIST OF EQUATIONS ................................................................................................................ x LIST OF ABBREVIATIONS & ACRONYM ................................................................................. xi LIST OF SYMBOLS & UNITS .................................................................................................. xiii CHAPTER 1 LITERATURE REVIEW ..........................................................................................1 1.1 Brief taxonomic overview ...............................................................................................1 1.1.1 Family Caprifoliaceae ..............................................................................................1