ANTIMICROBIAL EFFECTS OF THE LEAF EXTRACTS OF Chromolaena ordorata (Siam weeds) ON SOME HUMAN PATHOGENS

ABSTRACT

Antimicrobial effects of Chromolaena odorata (commonly called Siam weed), were tested on Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Different solvents such as methanol and chloroform were used for the leaf extraction. Test organism Pseudomonas aeruginosa and  Salmonella typhi were susceptible to methanol extracts of Chromolaena odorata at concentration of 25, 50 and 100mg/ml with zone of inhibition of 15mm, 19mm and 22mm respectively for Salmonella typhi and 29mm, 32mm and 36mm for Pseudomonas aeruginosa, while the chloroform extract produced similar concentration of 18mm, 20mm and 22mm for Salmonella typhi  and 19mm, 20mm and 21mm for Pseudomonas aeruginosa.  The Minimum Inhibitory Concentration (MIC) of methanol extract against Salmonella typhi and Pseudomonas aeruginosa were 12.5mg/ml and 3.12mg/ml respectively. The MIC of chloroform extract against Salmonella typhi and Pseudomonas aeruginosa were 6.25mg/ml and 6.25mg/ml. For the pathogen Staphylococcus aureus and Candida albicans, no MIC was carried out because there was no zone of inhibition seen on the plate with 100% concentration. This justifies the therapeutic use of Chromolaena odorata. This research work establishes a good support to the use of these plants in herbal remedies and for the development of new drugs.

TABLE OF CONTENTS 

 Title page ﾿ i

Certification ﾿ ii

Dedication ﾿ iii

Acknowledgements ﾿ iv

Table of Contents ﾿ v

List of Tables ﾿ vii

List of Plates ﾿ viii

Abstract ﾿ ix

CHAPTER ONE ﾿

1.1 ﾿ Introduction ﾿ 1

1.2 ﾿ Aims and Objectives ﾿ 3

CHAPTER TWO

2.0 ﾿ Literature review ﾿ 4

2.1 ﾿ Traditional uses of Chromolaena ordorata ﾿ 6   

2.2 ﾿ Phytochemicals and Chemotherapy ﾿ 6

2.3 ﾿ Phytochemical Screening ﾿ 7

2.4.1 ﾿ Nutritional value of Chromolaena ordorata ﾿ 7

2.4.2 ﾿ Antimicrobial Susceptibility testing ﾿ 8

2.4.3 ﾿ Antibacterial activity of the plant extracts ﾿ 8

2.4.4 ﾿ Antifungal activity of the plant extracts ﾿ 9

CHAPTER THREE

3.0 ﾿ Materials and methods ﾿ 10

3.1 ﾿ Materials ﾿ 10

3.2 ﾿ Methods ﾿ 10

3.2.1 ﾿ Sample collection ﾿ 10

3.2.2 ﾿ Preparation of extracts ﾿ 10

3.2.3 ﾿ Methanol extract preparation ﾿ 11

3.2.4 ﾿ Chloroform extract preparation ﾿ 11

3.2.5 ﾿ Preparation of stock solution of extracts ﾿ 11

3.2.6 ﾿ Media used ﾿ 11

3.2.7 ﾿ Media preparation ﾿ 12

3.2.8 ﾿ Collection of test bacterial isolates ﾿ 12

3.2.9 ﾿ Preparation of paper disc ﾿ 12

3.2.10 ﾿ Paper disc diffusion methods ﾿ 12

3.2.11 ﾿ Determination of Minimum Inhibitory Concentration ﾿ 13

CHAPTER FOUR

4.1 ﾿ Results ﾿ 14

CHAPTER FIVE ﾿

5.0 ﾿ Discussion and conclusion

5.1 ﾿ Discussion ﾿ 22

5.2 ﾿ Conclusion 

﾿ 23

References ﾿ 24 ﾿ ﾿

LIST OF TABLES

TABLES ﾿ TITLE ﾿       ﾿ PAGES

  1 ﾿ Zone Of Inhibition Of Methanol Extract On The

Test Organisms. ﾿                                 15

  2 ﾿ Zone Of Inhibition Of Chloroform Extract On

The Test Organisms. ﾿                             16

  3 ﾿ Zone Of Inhibition Produced By The Antibiotics 

Used As Controls ﾿                             17

  4 ﾿ The Minimum Inhibitory Concentration Of Methanol

 Plant Extracts Against Susceptible Organisms. ﾿       18

  5 ﾿ The Minimum inhibitory Concentration Of Chloroform

﾿ Plant Extract Against Susceptible Organisms. ﾿       19

LIST OF PLATES

PLATES ﾿ TITLE ﾿ PAGES

 1 ﾿ Diameter of Zone of Inhibition of the Methanol and

Chloroform extract of Chromolaena ordorata On

Salmonella typhi. ﾿     20

 2 ﾿ Diameter of Zone of Inhibition of the Methanol and 

Chloroform extract of Chromolaena ordorata On

 Pseudomonas aeruginosa. ﾿                          21