ABSTRACT
In African folk medicine, water infusion of Mangifera indica stem bark are highly valued in thelocal treatment of malaria fever, diarrohea, diabetes mellitus and liver diseases. Various part ofthis plant can also be used in treatment of toothache, dysentery, anemia, hypertension andinsomnia in different parts of the world. This study was described to determine the activities ofthe stem bark extract of M.indica against some panel of bacterial strains and also to evaluate thephytochemical compounds present in the plant extract.Mangifera indica stem bark was collected at Obafemi Awolowo University Campus, Ile-Ife. Thesample was air dried until constant weight was reached and was later ground into fine powder. The crude extract was prepared by soaking a known weight of the powder in mixture ofmethanol and sterile distilled water in ratio 3:2 (v/v), and left on laboratory bench for 96 h. Themixture was filtered and concentrated in vacuo using rotary evaporator. The antimicrobialactivity of the crude extract collected was determined by agar-well diffusion method. Theminimum inhibitory concentrations and minimum bactericidal concentrations were alsodetermined in addition to the phytochemical constituents of the plant extract.The extract showed appreciable activities against Bacillus subtilis (NCIB 3610). Bacillus cereus(NCIB 6349), Pseudomonas aeruginosa (NCIB 950), Klebsiella pneumoniae (NCIB 418),Micrococcus luteus (NCIB 167), Serratia marscescens (NCIB 1377), Escherichia coli (NCIB86), Staphylococcus aureus(NCIB 8588), Proteus vulgaris (NCIB 418), Pseudomonasaeruginosa (LIO), Staphylococcus aureus (LIO), Bacillus polymxa (LIO), Shigella sp. (LIO),Bacillus anthracis, Vibrio fluvialio (LIO), Enterococcus faecalis (NCIB775), Pseudomonasx fluorescence (NCIB) at final concentration of 20 mg/ml. The mean diameter of zones ofinhibition exhibited by the extract ranged between 11 mm and 25 mm while that of streptomycinwhich was used as the positive control ranged between 15 mm and 28 mm. The MIC exhibitedby the extract against susceptible organisms ranged between 0.16 mg/ml and 2.50 mg/ml whilethe MBC between 0.63 mg/ml and 5.00 mg/ml. The phytochemical analysis of the extractrevealed the presence of tannins, saponins, alkaloids, carbohydrate, resins, glycosides, andterpenoids.In conclusion, the stem extract of M.indica exhibited appreciable antimicrobial activity againstall of the bacteria used for this work and this supports its usefulness in folklore remedies. Theextract compared favorably with the standard antibiotics (streptomycin) used in this work
TABLE OF CONTENTS
Title page
Title page i
Certification ii
Dedication iii
Acknowledgments iv
Table of contents vii
List of Tables viii
List of plate ix
Abstract xi
CHAPTER ONE
1.0 Introduction and literature review 1
1.1 Introduction 3
1.2 Literature review 4
1.2.1 Microorganisms as casual agents of disease 4
1.2.2 Mechanisms of action of antimicrobial compound 5
1.2.2.1 Injury to cell membrane 6v
1.2.2.2 Inhibition of synthesis of cell wall peptidoglycan 7
1.2.2.3 Degradation of structure and function of cell wall 7
1.2.2.4 Inhibition of metabolic biological compounds synthesis 8
1.2.2 Resistance Mechanism of Antibiotics 8
1.2.3 Studies on the antimicrobial activity of some medicinal plants 10
1.2.4 Mangifera indica (Linn.) 13
CHAPTER TWO
2.0 Materials and Methods 142.1 Materials 14
2.1.1 Microorganisms 142.1.2 The plant specimen 14
2.1.3 Culture media used 142.1.4 Reagents used 15
2.2 Method 152.2.1 Collection and preparation of the stem extract of M.indica 15
2.2.2 Preparation of microorganisms used 16
2.2.3 Antimicrobial sensitivity testing of crude stem extract of M.indica against selected bacterial strains 16
2.2.4 Determination of minimum inhibitory concentrations (MICs) of the extract 17vi
2.2.5 Determination of minimum bactericidal concentrations (MBCs) of the extract 17
2.2.6 Phytochemical components of the stem extract of M.indica 19
CHAPTER THREE
3.0 Results 203.1 The extract obtained from the stem of M.indica 20
3.2 The antimicrobial sensitivity testing of the stem extract of M.indica against selected bacterial strains 21
3.3 The minimum inhibitory concentrations (MICs) exhibited by M.indica stem extract against susceptible bacterial strains 22
3.4 The minimum bactericidal concentrations (MBCs) exhibited by M.indica stem extract against susceptible bacterial strains 22
3.5 Phytochemical components revealed from of M.indica stem extract 23
CHAPTER FOUR
4.0 Discussion and Conclusion 24
4.1 Discussion 25
4.2 Conclusion 26
REFERENCES 33
APPENDIX 1
