ABSTRACT

Studies were carried out on the phytochemical compositions and in-vitro antimicrobial activities of crude extract of Chassalia kolly and Sida veronicaefolia against 20 isolates of Methicillin resistant Staphylococcus aureus (MRSA). This involved phytochemical screening and antimicrobial testing of methanol, ethyl acetate and aqueous extracts of Chassalia kolly and Sida veronicaefolia using basic pharmacognostic procedures and agar well diffusion  assay and broth dilution techniques on Methicillin resistant Staphylococcus aureus. Alkaloids, flavonoids, saponins and tannins were detected in all extracts.Tannin was the phytochemical that had the highest concentration in percentage (3.29% and 2.98% ) in the leaves of Chassalia kolly and Sida veronicaefolia respectively while flavonoid had the lowest concentration in percentage  (0.88%) in the leaves of Sida veronicaefolia and saponin (0.14%) in the leaves of Chassalia kolly.The agar well diffusion assay showed that the methanolic and ethyl acetate crude extract of  Chassalia kolly plant showed antimicrobial activities while the methanolic crude extract of Sida veronicaefolia exhibited little inhibitory action against few of MRSA isolates. There was a corresponding decrease in the zone of inhibition of the growth of the test organism as the concentration of the extracts decreased. The lowest minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) values of the methanolic extracts of Chassalia kolly and Sida veronicaefolia plants were 12.5mg/ml and 25mg/ml respectively and the highest being 100mg/ml while the lowest MIC and MBC  of the ethyl acetate extract of Chassalia kolly was 25mg/ml and 50mg/ml respectively with the highest as 25mg/ml for MIC and 50mg/ml for MBC. Findings from this study revealed that methanolic extracts of Chassalia kolly exhibited significant antimicrobial activities on methicillin resistant Staphylococcus aureus and thus suggests need to refine and standardize these extracts as alternative source of antimicrobial medicines.

TABLE OF CONTENTS

Title page

Certification i

Dedication ii

Acknowledgement iii

Table of contents iv

Lists of tables vii

Abstract viii

CHAPTER ONE

1.0 INTRODUCTION                                                                                               1

1.3 Aims and Objectives 4

CHAPTER TWO

2.0        LITERATURE REVIEW 7

2.1 Role of Traditional Medicine 7

2.2 Sida veronicaefolia (Family: Malvaceae) 9

2.2.1 Description 9

2.2.2 Medicinal  value    9

2.3 Chassalia kolly (Family: Rubiaceae) 10

2.3.1 Description 10

2.3.2 Medicinal  value    10

2.4  Phytochemicals  of medicinal plants 11

2.4.1 Flavonoids 12

2.4.2  Saponins 13

2.4.3 Tannins 13

2.4.4 Alkaloids 14

2.5  Mechanism of Action of Phytochemicals 15

2.6  Importance of medicinal plants in drug discovery 15

2.6.1 Plants Antagonism against Bacterial Pathogens 17

2.7 Antimicrobial Assay 18

2.8 Overview of test organism 19

2.8.1 Staphylococcus aureus 19

2.8.2.1  Invasion 21

2.8.2.2 MRSA pathogenesis 22

CHAPTER THREE

3.0 MATERIALS AND METHODS 23

3.1 Collection, authentication and processing of plant materials 23

3.2  Extraction of Plant Material                  23

3.3 Quantitative Determination of the Phytochemicals           24

3.3.1 Determination of Saponins 24

3.3.2 Determination of Flavonoids 25

3.3.3 Determination of Tannins 25

3.3.4 Determination of Alkaloids 26

3.4 Screening of the Extracts for Antibacterial Activity 27

3.5 Determination of MIC and MBC of the Crude Extracts            28

CHAPTER FOUR

4.0 RESULTS 29

CHAPTER FIVE

5.0 DISCUSSION 37

5.1 Conclusion 41

5.2 Recommendation              41

REFERENCES 42