ANTIBACTERIAL ACTIVITY OF Emilia coccinea AND Senna tora AGAINST SELECTED BACTERIAL PATHOGENS

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