ABSTRACT

Combretum racemosum (P. Beauv.) commonly known as “Christmas rose” in Southern Nigeria local English is a plant that has been in use for several years by African traditional healers in the treatment of haemorrhoids, convulsive coughing, tuberculosis, toothache, male sterility and as condiments in soups. This study was designed to evaluate the in vitro antioxidant and diuretic activities of the ethanolic extract of C. racemosum leaves on experimental model albino rats. The acute toxicity (LD50) of C. racemosum leaves was carried out on the albino rats using standard method. The result showed a lethal dose (LD50) > 5500mg/kg of the extract. In the in vitro antioxidant test, there was a concentration dependent increase in the percentage (%) scavenging activity when compared with the Vitamin C (control) for 2,2-diphenyl-1-picrylhydrazyl (DPPH), Nitric oxide and Anti-lipid peroxidation activity of C. racemosum leaves. The result exhibited a significant difference at higher concentration when compared to the control. The IC50 values of the plant extract were observed which measures its antioxidant effectiveness. The ethanolic extract also exhibited a significant increase in urine volume and the electrolyte at different concentration from 187.5mg/ml to 3000mg/ml. At 3000mg/ml (0.7 ± 0.14) and 1500mg/ml (0.45 ± 0.07) concentrations, the extract exhibited a significant difference in sodium (Na+) excretion (87.4 ± 1.70) and (76.65 ± 0.49) respectively. The potassium (K+), chloride (Cl-) and bicarbonate (HCO3-) level decreases as the concentration decreases from 3000mg/ml to 187.5mg/ml. The decrease in the electrolyte level as the concentration of the doses decreases exhibited a significant difference (P<0.05). From the result generated, the ethanolic extract of C. racemosum leaves is an effective natural antioxidant and can induce diuresis at very high dosage.

TABLE OF CONTENT

Title page i

Declaration ii

Certification iii

Dedication iv

Acknowledgement v

Table of contents vi

List of tables’ viii

List of plates and figures ix

Abstract x

CHAPTER ONE

1.0 Introduction 1

1.1 background of study 1

1.2 Aims and objectives 3

1.3 Justification 3

CHAPTER TWO

2.0 Literature review 4

2.1 Medicinal plants 4

2.2 Botanical description of Combretum racemosum 5

2.2.1 Uses of Combretum racemosum 6

2.3 Antioxidant 6

2.4 Diuretics 9

CHAPTER THREE

3.0       Materials and Methods 14

3.1 Material 14

3.1.1 Plant material 14

3.1.2 Extraction of the plant material 14

3.1.3 Experimental animal 14

3.2 Antioxidant activity of Combretum racemosum leaves 15

3.2.1 Determination of DPPH radical scavenging activity 16

3.2.2 Determination of Nitric oxide scavenging activity 16

3.2.3 Determination of Anti-lipid peroxidation activity 16

3.3 Diuretic activity 17

3.3.1 Experimental design 17

3.3.2 Measurement of urine output and analysis of electrolyte 17

3.4 Lethal Dose (LD50) 18

3.4.1 Acute toxicity test 18

3.5 Statistical analysis 18

CHAPTER FOUR

4.0 Result 20

4.1 Acute toxicity result 20

4.2 Evaluation of ethanolic extract fraction of C. racemosum for antioxidant activity 20

4.2.1 DPPH photometric assay 20

4.2.2 Evaluation of Nitric oxide inhibition activity of C. racemosum and Vitamin C 21

4.2.3 Evaluation of lipid peroxidation activity of C. racemosum and Vitamin C 22

4.3 Diuretic effect 23

CHAPTER FIVE

5.0 Discussion 28

5.1 Conclusion 31

REFERENCES