Phytochemical Screening And Antimicrobial Activity Of Euporbia Hirta Linn, Breynia Nivosa W. Bull, Euphorbia Heterophylla Linn And Manihot Esculenta Crantz

ABSTRACT

Euporbia hirta, Breynia nivosa, Euphorbia heterophylla and Manihot esculenta powdered plant material were extracted using two solvents, ethanol and water. The ethanol extracts provided the higher yield and also more antimicrobial effectiveness than aqueous extracts. Phytochemical screening of the crude extracts revealed the presence of alkaloids, saponin, tannins, flavonoids, phenols and hydrogen cyanide (HCN). The plant extracts had a high percentage of HCN ranging from 13.48±0.03 to 39.15±0.04%. The presence of these bioactive constituents have been linked to the antimicrobial activity of the plant materials. The disc diffusion method was used to determine the antimicrobial activity against Pseudomonas aeruginosa, Enterobacter aerogenes, Salmonella pullorum and Proteus vulgaris.Minimum inhibitory concentrations was analysed using agar well diffusion method with values ranging from 50 to 200mg/ml. The growth of all the bacteria were inhibited through to varying degrees, thus justifying the use of the herbs in traditional medicine in treating enteric infections. P. vulgaris and P. aeruginosa were more susceptible with diameters ranging from 19mm and 16.33mm respectively. The antimicrobial activity of the plant materials is enhanced under acidic conditions and at elevated temperatures. The herbs E. hirta, B. nivosa, E. heterophylla and M. esculenta can be used as sources of oral drugs to fight infections caused by susceptible bacteria.

TABLE OF CONTENTS

Cover page

Title page ﾿ i

Declaration ﾿ ii

Certification ﾿ iii

Dedication ﾿ iv

Acknowledgement ﾿ v

Table of content ﾿ vi

List of tables ﾿ viii

List of plates ﾿ ix

Abstract ﾿ x

CHAPTER ONE

INTRODUCTION ﾿ 1 ﾿

1.1 ﾿ Aim and Objectives ﾿ 2

1.2 ﾿ Justification ﾿ 3

1.3 ﾿ Botany of the plants ﾿ 3

1.3.1 ﾿ Botany of Manihot esculenta Crantz (Cassava) ﾿ 3

1.3.2 ﾿ Botany of Breynia nivosa W. Bull(Small-Snow bush) ﾿ 4

1.3.3 ﾿ Botany of Euphorbia hirta Linn (Asthma plant) ﾿ 5

1.3.4 ﾿ Botany of Euphorbia heterophylla Linn (Purge weed) ﾿ 6

CHAPTER TWO

2.1 ﾿ Literature review ﾿ 7

2.1.1 ﾿ Phytochemical screening of plants ﾿ 7

CHAPTER THREE

3.0 ﾿ Materials and methods ﾿ 10

3.1 ﾿ Collection of plant materials and identification ﾿ 10

3.1.1 ﾿ Preparation of the samples for analysis ﾿ 10 ﾿

3.2 ﾿ Phytochemical analysis ﾿ 11

3.2.1 ﾿ Qualitative analysis on leaf extract ﾿ 11

3.1.1. ﾿ Test for the presence of tannins ﾿ 11

3.2.1.2 Test for the presence of saponins ﾿ 11

3.2.1.3 Test for flavonoids ﾿ 12

3.2.1.4 Test for the presence of Alkaloids ﾿ 12

3.2.1.5Test for the presence of phenols ﾿ 13

3.3 ﾿ Quantitative analysis of phytochemicals ﾿ 13

3.3.1 ﾿ Determination of tannins ﾿ 13

3.3.2 ﾿ Determination of alkaloids ﾿ 14

3.3.3 ﾿ Determination of phenols ﾿ 15

3.3.4 ﾿ Determination of flavonoids ﾿ 16

3.3.5 ﾿ Determination of saponin ﾿ 17

3.3.6 ﾿ Determination of hydrogen cyanide (HCN) ﾿ 18

3.4 ﾿ Determination of antimicrobial activity ﾿ 19

3.4.1 ﾿ Production of plant extracts ﾿ 19

3.4.2 ﾿ Source of test organisms ﾿ 20

3.4.4 ﾿ Determination of minimum inhibitory concentration ﾿ 21

3.4.5 ﾿ Statistical Analysis ﾿ 22

CHAPTER FOUR

4.0 ﾿ Results ﾿ 26

4.1 ﾿ Phytochemical properties ﾿ 26

4.1.1 ﾿ Quantitative analysis ﾿ 26

4.1.2 ﾿ Qualitative analysis ﾿ 27

4.1.3 ﾿ Antimicrobial activity ﾿ 29

4.1.4 ﾿ Minimum inhibition concentration (MIC) ﾿ 30

CHAPTER FIVE

5.0 ﾿ Discussion and conclusion ﾿ 37

5.1 ﾿ Discussion ﾿ 38

5.2 ﾿ Conclusion ﾿ 43

References