Antibacterial Activities Of Allium Cepa (Onion) On Two Bacterial Isolates

ABSTRACT

This study was conducted to ascertain the antibacterial activities of crude onion (Allium cepa) extract on some pathogenic bacteria isolates associated with ocular infection. This experimental study was carried out in the university premises, Michael Okpara University of Agriculture Umudike, Abia State, Nigeria. The antibacterial activity of onion extract on Staphylococcus aureus  and Escherichia coli was measured by disc diffusion method. Gentamycin was used as control for antibacterial activity. The effect on the antibacterial activities of Onion bulb (Allium cepa) was carried out and two different extracts were made from onion (Allium cepa) using distilled water. The extracts   include fresh onion extract and cold water extract. The antibacterial activity of the onion was tested on two bacteria isolates associated with ocular infections. The bacterial isolates include: Staphylococcus aureus, and Escherichia coli and. Among the two extracts, fresh onion extracts exhibited antagonistic effects on the test organisms ranging from observed zone of inhibition (average value) of 14mm for Staphylococcus aureus, 12mm for Escherichia coli. The antibiotic used as control was gentamycin with zone of inhibition of 17mm for Staphylococcus aureus, and 18mm for Escherichia coli. The minimum inhibitory concentration of the potent onion extracts shows positive inhibitory effect when an undiluted onion extracts was used. From the research conducted it was concluded that fresh onion extract could be the alternanative of the antibiotic to cure bacterial infection. However, pharmacological  Standardization and clinical assessment of this effect are essential before using onion extract as a preventive measure for human eye.

TABLE OF CONTENTS

Title                                                                                                         page

Title Page                                                                                                                                i

Certification ﾿                                                                                                                         ii

Dedication ﾿             iii

Acknowledgement ﾿ iv

Table of Content ﾿ v

List of Tables ﾿             vii ﾿                                                                                                             

Abstract ﾿             viii

CHAPTER ONE

1.0 ﾿       Introduction ﾿                                                                                                             1

1.2 ﾿ Aim and Objectives ﾿ 4

CHAPTER TWO

1.0 ﾿ Literature Review ﾿ 5

1.1 ﾿ Botanical Source ﾿ 5

1.2 ﾿ Chemical Composition of Onion ﾿ 6

2.3       Food Value of Onion ﾿ 7

2.4 ﾿ Medicinal Uses of Onion ﾿ 7

2.5 ﾿ Health Benefits Of Onion ﾿ 8

2.6 ﾿ Medicinal Importance and Application ﾿ 11

2.7 ﾿ Antibacterial Activities of Onion ﾿ 14

2.7.1 ﾿ Antiviral Activities of Onion ﾿ 15

2.7.2 ﾿ Antifungal Activities of Onion ﾿ 15

2.7.3     Antiparasitic Activity of Onion ﾿ 16

2.7.4     Antioxidant Activity of Onion ﾿ 16

2.7.5 ﾿ Anticarcinogenic and Antimutagenic Activities of Onion ﾿ 18

CHAPTER THREE

3.0 ﾿ Materials and Methods ﾿ 20

3.1 ﾿ Materials ﾿ 20

3.1.1 ﾿ Sterilization Methods ﾿ 20

3.1.2 ﾿ Media Preparation ﾿ 20

3.1.3 ﾿ Preparation and Standardization of Bacterial Inoculum ﾿ 20

3.2 ﾿ Extraction of Crude from Onion Bulb (Allium cepa) of Onion ﾿ 21

3.2.1 ﾿ Preparation of Concentration of Onion Extract ﾿ 21

3.3 ﾿ Isolation, Identification and Confirmation of Some Pathogenic

 Bacteria Associated with Ocular Infection ﾿ 21

3.3.1 ﾿ Gram Staining ﾿ 21 ﾿

3.4 ﾿ Determination of the Inhibitory Concentration of the Extracts of 

The Isolates and to Measure the Zone of Inhibition ﾿             22

3.4.1 ﾿ Determination of Minimum Inhibitory Concentration of the Onion

﾿ (Allium Cepa) ﾿             22

3.4.2 ﾿ Determination of Minimum Bacterial Concentration (MBC) ﾿ 22

3.5 ﾿ Media ﾿ 23

3.6 ﾿ Biochemical Reaction ﾿ 23

 CHAPTER FOUR

4.0 ﾿ Results ﾿ and Discussion ﾿ 26

CHAPTER FIVE 

5.0 ﾿ Discussion ﾿ 34

5.1 ﾿ Conclusion ﾿ 35

5.2 ﾿ Recommendation ﾿ 35

REFERENCES