Effects of Crude Leaf Extracts of Ficus Thonningii
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EFFECTS OF CRUDE LEAF EXTRACTS OF FICUS THONNINGII ON GROWTH, GASTROINTESTINAL MORPHOMETRY AND CLINICAL BIOCHEMISTRY OF SUCKLING SPRAGUE DAWLEY RATS Rachael Dangarembizi A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science in Medicine Johannesburg, 2012 DECLARATION I declare that this dissertation is my own work, with the aid of the acknowledged persons. This dissertation is being submitted for the degree of Master of Science in Medicine in the Faculty of Health Sciences at the University of the Witwatersrand, Johannesburg. It has not been submitted before for any degree or examination at this or any other University. All procedures used in this dissertation were approved by the Animal Ethics screening Committee of the University of the Witwatersrand (AESC number 2011/22/2A). ………………………………… ………day of…………………2012 ii DEDICATION To my loving family, who have stood behind me in all my endeavours. To my supervisors, colleagues and friends: for the tireless support and motivation. To my late mother and my best friend: This is just one step up, the goal gets nearer and nearer with each coming day. iii ABSTRACT Ficus thonningii is a nutraceutical that is extensively used in ethnomedicine. Nursing mothers use F. thonningii leaves as nutritional and medicinal supplements and are at risk of exposing their infants to its constituent phytochemicals. The exposure of the sensitive neonatal gastrointestinal tract (GIT) to these phytochemicals can result in irreversible changes in growth and development. The objectives of this study were to determine the effects of crude F. thonningii extracts on; growth, morphology and morphometry of the abdominal viscera and clinical biochemistry of neonatal rats. Forty, suckling Sprague Dawley rats of either sex were randomly divided into 5 groups. Each group was orally gavaged once daily with either low (50 mg/kg b.w) or high (500 mg/kg b.w) doses of aqueous or methanolic extracts of F. thonningii , for 7 days. The control rats received distilled water. The pups were euthanased and tissues were collected and weighed. Samples of the liver, caecum and proximal small intestine were preserved and processed for histology. Plasma biochemical parameters were analysed colorimetrically. Data was presented as means + SD. F. thonningii extracts exhibited trophic effects on the stomach and ceacal mucosa of rats but had no significant growth-promoting effects on the small intestine and visceral organs. Histological analysis of the intestine, liver and caeca revealed no mucosal damage. Clinical chemistry parameters were not abnormally altered. There was a significant decrease (p<0.05, ANOVA) in the plasma concentrations of basal (non-fasting) glucose in the pups iv on the high methanolic extracts. However, the triglyceride and cholesterol levels were unaltered by the treatments. The findings suggest that F. thonningii extracts exhibit trophic effects on the mucosal layers of the stomach and caecum. F. thonningii extracts also possess glucose-lowering activity. At low doses, F. thonningii extracts can be safely used without the risk of any disruption in the structural integrity of the neonatal rat GIT and function of the liver and kidneys. v ACKNOWLEDGEMENTS First and foremost, I would like to thank the Lord for His guidance and for opening windows of opportunity in my life. I am deeply indebted to my supervisors Mr Eliton Chivandi and Assoc. Professor Kennedy Erlwanger for their guidance, constant encouragement and tireless support. This work wouldn’t have been successful without your invaluable assistance. I am sincerely grateful to my colleagues Davison Moyo, Zinhle Gasa, Trevor Nyakudya and Janine Donaldson for assisting throughout the course of my studies. A heartful thanks goes to Margaret Badenhorst for offering her technical help in processing tissues for histology. Special thanks also goes to John and Sandra Burrows, Walter Barker and Donald McCallum for assistance with species identification. I would like to thank the CAS staff; Amelia Rammekwa, Lorraine Setimo and Nico Douths for the technical assistance rendered during my animal studies. I would like to express my sincere gratitude to the University of the Witwatersrand, the National Research Foundation and the National University of Science and Technology (NUST) for sponsorship that made this work possible. I am obliged to the Dean and staff at the Faculty of Medicine (NUST) for their continued support throughout the course of my study. vi Last but not least I owe my sincere and earnest gratitude to my family and friends for the support, love and encouragement throughout the course of my study. My most sincere gratitude goes to my best friend Bright for the unwavering support and motivation in all my endeavours. vii TABLE OF CONTENTS DECLARATION ................................................................................................................. ii DEDICATION .................................................................................................................... iii ABSTRACT ........................................................................................................................ iv ACKNOWLEDGEMENTS ............................................................................................... vi LIST OF FIGURES .......................................................................................................... xiii LIST OF TABLES ............................................................................................................ xiv LIST OF ABBREVIATIONS ........................................................................................... xv CHAPTER 1-INTRODUCTION AND LITERATURE REVIEW ................................ 1 1.0. Background ............................................................................................................. 2 1.1. Ficus thonningii ....................................................................................................... 3 1.1.1. Botany and Taxonomy ............................................................................................ 3 1.2. Biochemistry ........................................................................................................... 5 1.2.1. Nutritional value ...................................................................................................... 5 1.2.2. Phytochemical composition .................................................................................... 7 1.2.2.1. Flavonoids ............................................................................................................... 7 1.2.2.2. Tannins .................................................................................................................... 8 1.2.2.3. Alkaloids ................................................................................................................. 9 1.2.2.4. Terpenoids ............................................................................................................... 9 1.2.2.5. Essential oils .......................................................................................................... 10 1.2.2.6. Other phytochemicals ............................................................................................ 10 1.3. Ethnomedicinal uses .............................................................................................. 11 viii 1.3.1. Leaves .................................................................................................................... 11 1.3.2. Stem Bark .............................................................................................................. 12 1.3.3. Roots ...................................................................................................................... 12 1.3.4. Latex ...................................................................................................................... 13 1.3.5. Uses of F. thonningii in combination with other plants ........................................ 13 1.4. Phytopharmacology ............................................................................................... 14 1.4.1. Antimicrobial activity............................................................................................ 14 1.4.1.1. Antibacterial effects .............................................................................................. 14 1.4.1.2. Antiprotozoal properties ........................................................................................ 17 1.4.1.3. Antifungal effects .................................................................................................. 18 1.4.2. Anthelmintic properties ......................................................................................... 19 1.4.3. Antioxidant activity ............................................................................................... 19 1.4.4. Analgesic effects ................................................................................................... 20 1.4.5. Anti-inflammatory effects ..................................................................................... 21 1.4.6. Cardioprotective effects ........................................................................................ 21 1.4.7. Hypoglycemic effects ............................................................................................ 22 1.4.8. Antidiarrheal effects .............................................................................................