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. PhD. (Chemistry)/ M.Sc. (Physics)/ M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved from: https://ujcontent.uj.ac.za/vital/access/manager/Index?site_name=Research%20Output (Accessed: Date). An inventory of the most popular medicinal barks sold on Johannesburg muthi markets and the antimicrobial activity of selected extracts and isolated chemical compounds By Gugulethu Philadelphia Khumalo Dissertation submitted In fulfilment of the requirements For the degree MAGISTER SCIENTIAE In BOTANY In the FACULTY OF SCIENCE At the UNIVERSITY OF JOHANNESBURG SUPERVISOR: PROF. B-E. VAN WYK CO-SUPERVISOR: DR. N.J. SADGROVE CO-SUPERVISOR: PROF. S.F. VAN VUUREN JULY 2018 Affidavit I, Gugulethu Philadelphia Khumalo, declare that this dissertation is my own work. It has only been submitted (by myself) for the degree of Master of Science in Botany at the University of Johannesburg. It has never been submitted before for any degree or examination at any other University. I also state that all the sources that I have used herein have been appropriately acknowledged. Signature (Student) : _ _______________ This 25th day of July 2018 Signature (Supervisor) : _ _______________ This 25th day of July 2018 i Dedication I dedicate this Master’s dissertation to God whom I praise, for I do not believe that I could have made it possible. I thank Him for my life. I am also dedicating this dissertation to my 11 year old little sister, Samukelisiwe Khumalo. I want you to know that if I managed to achieve this, so can you. This should be like footprints I am leaving you with, to follow a peaceful educational path that will train you to be independent for, I will not always be there throughout your life to guide you. To my parents, even though you did not make it to University but you managed to create a University graduate. Therefore, you should be proud of yourselves. ii Acknowledgements I would first like to thank my supervisor, Professor Ben-Erik van Wyk, for believing in my abilities by offering me an opportunity to work under his guidance as one of the best and internationally recognised researchers. A great learning experience indeed that channelled me in the right direction. I thank you Prof for your financial, mental and academic support – it has greatly contributed to my personal growth. I would also like to thank the experts who allowed for collaboration, with their commitment and inputs in my research project thus making it a success; my co-supervisors, Professor Sandy van Vuuren and Dr Nick Sadgrove. I thank you Prof for welcoming me into your lab and giving me an opportunity to learn and understand antimicrobial screening. To Dr Nick Sadgrove, I thank you so much for sharing your chemistry skills with me. I would like to thank Dr Ekaterina Kotina, a bark anatomist, for her assistance with the interpretation of morphological bark characters that can be used for identification. I thank the National Research Fund for financial assistance in pursuing my Master’s degree and the University of Johannesburg for giving me the platform to learn. I would like to thank the postgraduate students and staff members from the Department of Botany and Plant Biotechnology for their support. I would like to thank the Johannesburg muthi market traders for allowing me to communicate with them and for sharing their knowledge on the uses of medicinal barks. Special thanks to Gogo Makhaza, Mkhulu Madondo, Bab’ Nqulunga and Mancube. iii I would like thank my mother, Ntombizodwa Khumalo, brother, Sfiso Buthelezi, and mamncane Mrs Bonisiwe Ngcenwa for financial support, particularly during the final stage of this Master’s degree study. I would like to thank my brothers and sisters in Christ under The Twelve Apostles Church in Christ for allowing God to give me spiritual guidance through them. I thank you for all the support you invested in me. I would like to give special thanks to Zamani Ncanana for being an inspiration to further my studies, for being a true friend, for psychological, emotional and spiritual support. I thank you so much. I would like to thank my family and the community of Diepkloof in Soweto for being a silent inspiration that has encouraged me to work hard. iv List of Contents Affidavit ................................................................................................................................ i Dedication ........................................................................................................................... ii Acknowledgements ........................................................................................................... iii List of Contents ................................................................................................................... v List of Figures .................................................................................................................. viii List of Tables ...................................................................................................................... xi Summary .......................................................................................................................... xiii CHAPTER 1. INTRODUCTION ................................................................................. 1 1.1 General introduction ................................................................................................. 1 1.2 Objectives of this study ............................................................................................ 9 CHAPTER 2. INVENTORY OF POPULAR MEDICINAL BARKS ........................... 11 2.1 Introduction ............................................................................................................. 11 2.2 Materials and methods ............................................................................................ 14 2.2.1 The Muthi Markets .............................................................................................. 15 2.2.1.1 The Faraday Muthi Market ............................................................................ 15 2.2.1.2 The Kwa Mai-Mai Muthi Market .................................................................... 17 2.2.2 Trader information and data recorded ................................................................. 21 2.3 Results and discussions ......................................................................................... 22 2.3.1 Traders on the muthi markets.............................................................................. 22 2.3.2 Gender information on traders at the Johannesburg muthi markets .................... 24 2.3.3 Diversity of bark on the muthi markets ................................................................ 25 2.3.4 Method of preparation and mode of administration .............................................. 46 2.3.5 Main uses of medicinal barks .............................................................................. 49 2.3.6 Identification of medicinal barks .......................................................................... 57 2.3.7 Conservation status of bark species .................................................................... 87 2.4 Summary .................................................................................................................. 91 2.5 Conclusions ............................................................................................................. 92 CHAPTER 3. ANTIMICROBIAL ACTIVITY OF SELECTED EXTRACTS ............... 93 3.1 Introduction ............................................................................................................. 93 3.1.1 Role of bark for skin ailments .............................................................................. 95 3.1.2 Role of bark for respiratory ailments .................................................................... 96 3.1.3 Role of bark for gastrointestinal tract ailments ..................................................... 98 3.2 Materials and methods .......................................................................................... 100 3.2.1 Plant extraction ................................................................................................. 100 v 3.2.2 Minimum inhibitory concentration (MIC) technique ............................................ 101 3.3 Results and discussions ....................................................................................... 104 3.3.1 Skin ailments ..................................................................................................... 104 3.3.2 Gastrointestinal tract ailments ........................................................................... 108 3.3.3 Respiratory tract ailments .................................................................................. 114 3.3.4 The influence of solvent extract on the antimicrobial activity of the