ABSTRACT

This study was to access the antimicrobial and antioxidant properties of Tetraplera tetraptera on some human pathogens. The antimicrobial activity of Tetraplera tetraptera on some pathogens was investigated with different solvents (Ethanol, Methanol, Cold and Hot water) against test organisms (Esherichia coli, Staphylococcus aureuas, Salmonella spp, Shigella, Aspergillus and Candida albican). The different extracts were prepared at different concentration (50mg/ml, 100 mg/ml, 150mg/ml and 200mg/ml). Amongst the different Tetraplera tetraptera extracts studies, ethanolic extract generated more phytochemical constituents than the methanol, cold water and hot water extracts. The study revealed that the ethanolic extract had more significant inhibitory effect than methanolic, cold water and hot water extracts. Salmonella spp. and Staphylococcus aureus, had the highest sensitivity (15mm, and 16mm) against the methanol and ethanol extract of Tetraplera tetraptera, followed by Aspergillus niger on the ethanolic extracts of Tetraplera tetraptera at 14mm. Ciprofloxacin and Chloramphenicol were used as control. The antioxidant potentials of Tetraplera tetraptera plant extracts have been linked with their flavonoids contents may provide anti-inflammatory activity. Ethanolic extracts and methanolic extracts of Tetraplera tetraptera have broad-spectrum antimicrobial activity; hence can serve as natural therapeutic agent against some enteric pathogens.

TABLE OF CONTENTS

Title Page     i

Certification iii

Dedication iv

Acknowledgement v

Table of Contents vi

List of Tables vii

Abstract ix

CHAPTER ONE

Introduction 1

1.1 Aim and Objectives 4

CHAPTER TWO

Literature Review 6

2.1 Description of the Plant and Use 6

2.2 Classification of Phytochemicals 7 

2.2.1 Tannins 7

2.2.2 Flavonoids 7

2.2.3 Organic Acids 8

2.2.4 Phenols 8

2.2.5 Nitrogenous Compounds 8

2.2.6 Terpenes or Terpenoids 8

2.2.7 Alkaloids 9

2.2.8 Saponins 9

2.3 Antioxidant Properties of Phenolic Compounds 10

2.4 Antioxidant Activity of Aromatic Plants 12

2.5 Antioxidant Activity from Aroma Compounds and Essential Oils 13

2.6 Essential Oils as Antioxidants in Foods 16

2.8 Biology and Pathogenecity of Test Organisms 18

2.8.1 Escherichia coli 18

2.8.2 Salmonella 18

2.8.3 Shigella 19

2.8.4 Candida albicans 19

2.9 Comparative Study of the Phytochemical Composition of the Leaves of 

Five Nigerian Medicinal Plants 20

CHAPTER THREE

Materials and Methods 21

3.1 Sample Collection 21

3.2 Sterilization of Materials 21

3.3 Preparation of Extracts 21

3.3.1 Ethanolic and Methanolic Extract Preparation 21

3.3.2 Preparation of Different Concentration of Extract 22

3.4 Biochemical Identification of the Test Organisms 22

3.4.1 Catalase Test 22

3.4.2 Indole Test 22

3.4.3 Citrate Utilization Test 22

3.4.5 Motility Test 23

3.4.6 Voges-Proskauer Test 23

3.4.7 Methyl Red Test 23

3.5 Determination of Antimicrobial Activity 24

3.6 Determination of Minimum Inhibitory Concentration (MIC) 24

3.7 Determination of Minimum Bactericidal Concentration 25

3.8 Phytochemical Screening of the Extract 25

3.8.1 Qualitative Analysis 25

3.9 Methods for Testing Antioxidative Activity 26

3.10 Determination of Minerals 26

3.10.1 Calcium and Magnesium Determination 26

3.11 Determination of Vitamins 27

3.11.1 Thiamine (VIT B1) Determination 27

3.11.2 Riboflavine (VIT B2) Determination 28

3.11.3 Niacin Content Determination 28

3.11.4 Determination of Vitamin C 29

CHAPTER FOUR

Results 28

4.1. Qualitative Phyto-Chemical Constituents of Tetrapleura tetraptera Leave Extract 30

4.2. Identification and Characterization of Indicator Bacterial 30

4.3. Identification and Characterize of Test Organisms (Fungal) 30

4.4. Antimicrobial Activity of Tetrapleura Tetraptera Plant Extract against Fungi, 

Gram Positive and Negative Human Pathogen 30

4.5a. Minimum Inhibitory Concentration and Maximum Bactericidal Concentration 

Value of Tetrapleura Tetraptera against Test Bacteria and Fungi 31

4.5b. Minimum Bactericidal Concentration Value of Tetrapleura Tetraptera against 

Test Bacteria and Fungi 31

4.6. Vitamin Composition Analysis of Tetrapleura Tetraptera Plant Leaf 32

CHAPTER FIVE

5.0 Discussion, Conclusion and Recommendation 40

5.1 Discussion 40

5.2 Conclusion 42

5.3 Recommendation 42

References