ABSTRACT

Medicinal plants represent potential sources of novel compounds to treat Bacterial infections. In this work, the antimicrobial activities of ethanol extracts of two medicinal plants, Emilia coccinea and Senna tora, were evaluated using the disc agar diffusion technique. The plant extracts were tested at 25mg/ml, 50mg/ml and lOOmg/ml against five bacterial species [Pseudomonas aeruginosa ATCC 27853, Enterococcus faecalis ATCC 7080, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Salmonella typhi (local isolate)]. The ethanol extracts of these plants had no inhibitory effect on the growth of the test organisms. The results of this study fail to validate the ethanomedical uses of these plants for the treatment of bacterial infections.

TABLE OF CONTENTS

Title Page i

Certification ii

Dedication iii

Acknowledgments iv

Table of Contents v

List of Tables vii

List of Figures viii

Abstract ix

CHAPTER ONE

1.0 Introduction 1

1.1 Aims and Objectives 3

CHAPTER TWO

2.0 Literature Review 4

2.1 Emilia coccinea 4

2.1.1 Taxonomic classification 5

2.1.2 Plant Description 5

2.1.3 Antimicrobial Activity 7

2.1.4 Phytochemical Examination 10

2.2 Senna  tora 11

2.2.1 Taxonomic Distribution 12

2.2.2 Botany 12

2.2.3 Chemistry 14

2.2.4 Bioactivity 15

2.2.5 Antibacterial, Antifungal and Antishigellosis Activity 18

2.2.6 Antioxidant Activity 21

2.2.7 Antidiabetic Activity 24

CHAPTER THREE

3.0 Materials and Methods 27

3.1 Plant Materials 27

3.2 Test Microorganisms 27

3.3 Antimicrobial Testing 27

3.4 Phytochemical Screening 28

3.4.1 Test for Tannins 29

3.4.2 Test for Phenols 29

3.4.3 Test for Saponin 29

3.4.4 Test for Flavonoids 29

3.4.5 Test for Alkaloid 29

CHAPTER FOUR

4.0 Results 31

CHAPTER FIVE

5.0 Discussion and Conclusion 35

5.1 Discussion 35

5.2 Conclusion 37

5.3 Recommendations 38

Reference

Appendix

LIST OF TABLES

Table Title Page

1 Qualitative Phytochemical Analysis of Emilia coccinea and Senna tora Leaf Samples 32

2 Quantitative Phytochemical Analysis of Emilia coccinea and Senna tora Leaf Samples 33

3 Diameter zones of Inhibition (mm) produced by the ethanol extract of Emilia coccinea and Senna tora against test organisms 34

LIST OF FIGURES

Figure Title Page

1 An image of Senna tora plant 48

2 An image of Emilia coccinea plant in the field 49