PHYTOCHEMICAL SCREENING AND ANTIBACTERIAL ACTIVITY OF CRUDE ROOT AND STEM BARK OF Lannea acida

                ABSTRACT
Lannea acida is a plant known to have various medicinal and therapeutic properties. The 
phytochemicals or secondary metabolites and antibacterial activity of its root and stem bark were 
studied in this research work. The phytochemical screening of the plant was carried out using  standard methods of analysis and these investigations revealed the presence of bioactive  components comprising flavonoids, alkaloids, saponins, steroids, terpenoids, glycosides and 
phenols while tannins were not detected in both the root and stem bark of the plant. The plant  was extracted with water and 100% methanol via cold maceration method and the extracts were 
subjected to antibacterial activities using the agar plate disc diffusion and nutrient broth dilution   techniques. against E. coli, S. aureus and Shigella spp to ascertain its medicinal and therapeutic  properties at various concentrations range from 50 mg/mL – 6.25 mg/mL. From the study it was  observed that the stem bark extract has the higher antibacterial activity against E. coli and  Shigella spp with mean zone of inhibition of 18.50 ± 0.02 and 14.10 ± 0.12 mm while the root 
recorded the higher antibacterial activity against S.aureus with mean zone of inhibition of 16.37 
± 0.07 mm. The result indicates that the extracts of the root and stem bark of this plant possess antibacterial  activities.

            TABLE OF CONTENT
 Contents Pages
DECLARATION .................................................................................................................................iii
CERTIFICATION................................................................................................................................iv
DEDICATION ......................................................................................................................................v
ACKNOWLEDGEMENTS .................................................................................................................vi
TABLE OF CONTENTS…………………………………………………………………...vii
LIST OF TABLES…………………………………………………………………………...x
LIST OF FIGURES…………………………………………………………………………xi
ABSTRACT………………………………………………………………………………………xii
CHAPTER ONE............................................................................................................................. 1
1.0 INTRODUCTION........................................................................................................... 1
1.1 Background of the Study................................................................................................. 1
1.2 Statement of the Problem................................................................................................ 2
1.3 Justification of the Study................................................................................................. 3
1.4 Scope of the Study........................................................................................................... 3
1.5 Aim and objectives of the Study ...................................................................................... 3
1.5.1 Aim.......................................................................................................................................3
1.5.2 Objectives.............................................................................................................................3
CHAPTER TWO ............................................................................................................................ 4
2.0 LITERATURE REVIEW................................................................................................. 4
2.1 Medicinal Plants............................................................................................................... 4
2.1.1 Lannea acida........................................................................................................................4
2.2 Test Microorganisms........................................................................................................ 6
2.2.1 Escherichia coli....................................................................................................................6
2.2.2 Shigella spp ..........................................................................................................................6
2.2.3 Staphylococcus aureus.........................................................................................................7
2.3 Phytochemicals In Medicinal Plants............................................................................... 7
2.3.1 Tannins.................................................................................................................................8
2.3.2 Flavonoids..........................................................................................................................10
2.3.3 Alkaloids............................................................................................................................11
2.3.4 Saponins.............................................................................................................................14
2.3.5 Phenols...............................................................................................................................15

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................................................................................................ 21

3.6.2 Qualitative Phytochemical Analysis of the Plant Extracts ................................................. 22

3.6.2.1 Test for Tannins .............................................................................................................. 22

3.6.2.2 Test for Flavonoids ......................................................................................................... 22

3.6.2.3 Test for Alkaloids ........................................................................................................... 22

3.6.2.4 Test for Saponins ........................................................................................................... 23

3.6.2.5 Test for Phenols ............................................................................................................. 23

3.6.2.6 Test for Steroids ............................................................................................................ 23

3.6.2.7 Test for Terpenoid .......................................................................................................... 23

3.6.2.8 Test for Glycoside ......................................................................................................... 23

3.6.3 Antibacterial Activities of the Plant Extracts ...................................................................... 24

3.6.3.1 Test Organisms ................................................................................................................... 24

3.6.3.2 Preparation of the Standard Inocula of the Organisms ........................................................ 24

3.6.2.3 Culture Media ..................................................................................................................... 24

3.6.2.4 Determination of Antibacterial Activity of the Plant Extracts. ........................................... 24

3.6.2.5 Determination of Minimum Inhibitory Concentration of the Plant Extracts...................... 25

3.6.2.6 Determination of Minimum Bactericidal Concentration of the Plant Extracts. .................. 25

CHAPTER FOUR ......................................................................................................................... 26

4.0 RESULTS AND DSCUSSION ..................................................................................... 26

4.1 Result ............................................................................................................................. 26

4.1.1 Percentage Recovery of Extracts ......................................................................................... 26

4.1.2 Physical Properties of the Plant Extracts ............................................................................. 26................................................................ 29

ix

4.1.4 Antibacterial Sensitivity Test .............................................................................................. 33

4.1.5 Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) ................................................................................................................................. 39

4.2 DICUSSION OF RESULTS .......................................................................................... 45

4.2.1 Percentage Recovery of the Extracts .................................................................................. 44

4.2.2 Physical Properties of the Plants Extracts ........................................................................... 44

4.2.3 Qualitatitive Phytochemical Screening of the Plant Extracts .............................................. 44

4.2.4 Antibacterial Activity of the Extracts .................................................................................. 45

4.2.5 Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of Extracts.. .............................................................................................................................. 47

CHAPTER FIVE .......................................................................................................................... 48

5.0 SUMMARY, CONCLUSION AND RECOMMENDATIONS ................................... 48

5.1 Summary ....................................................................................................................... 48

5.2 Conclusion ..................................................................................................................... 48

5.3 Recommendations ......................................................................................................... 49

REFERENCES .................................................................................................................................... 50