ABSTRACT

Oral and Skin infections are among the leading causes of death worldwide. Pathogenic bacteria are becoming resistance to the existing antibiotics and many of the commercially available antimicrobial drugs. Therefore, there is need to explore medicinal plants as rich reservoir for the discovery of a safe complementary and alternative drugs that can be harnessed for human benefit. The present work aimed at investigating the total phenolic, total flavonoid, antibacterial, antioxidant and TLC profiling of some medicinal plants used traditionally for the treatment of oral and skin infections in Ohafia, Abia State. Such plants are: Ipomoea involucrata, Acalypha hispida, Breynia nivosa, Jatropha curas, Chromolaena odorata, Macrolobium macrophyllum, Eleusine indica, Baphia nitida, Burkea africana, and Cassia alata. The antioxidant potential, antibacterial, total phenolic and flavonoid of methanolic extract were investigated using in vitro standard bioassays methods. DPPH, ABTS, and FRAP were used to evaluate the antioxidant ability of the extract. Disc diffusion agar and Minimum Inhibitory Concentration (MIC) were used to evaluate the antibacterial activities. TLC profiling using silica gel coated on a glass with a solvent ratios of chloroform and methanol (6:4) and toluene, ethyl acetate and acetic acid (5:4:1) were used to separate polar and mid-polar compounds respectively. The plant extracts demonstrated a robust antioxidative potential and a potent antibacterial activity against the clinically isolated bacteria. The result of this study partly lend credence to the ethno-medicinal use of these plant by the traditional healers. Further work is suggested to isolate, characterize, and identify active principles in these botanicals via bio-guided assays and their toxicological studies for drug discovery.

TABLE OF CONTENT

Cover page………………………………………………………………………………...0

Title page………………………………………………………………………………..…i

Declaration………………………………………………………………………………....ii

Certification…………………………………………………………………………….…iii

Dedication………………………………………………………………………………....iv

Acknowledgement……………………………………………………………………….....v

Abstract…………………………………………………………………………………….vi

Table of figures, plate and tables…………………………………………………………..vii

Table of content……………………………………………………………………………viii

  CHAPTER ONE

1.0    Introduction……………………………………………………………………………1

1.1    Aim…………………………………………………………………………………….3

1.2    Objectives………………………………………………………………………….......3

1.3    Justification……………………………………………………………………….……3

CHAPTER TWO

2.0   Literature Review……………………………………………………………..………..4

2.1.1   Chromolaena odorata……………………………………………………...................5

2.1.2   Breynia nivosa …………………………………………………………………..……7

2.1.3   Jatropha curcas…………………………………………………………………….....9

2.1.4   Acalypha hispida……………………………………………………………………...11

2.1.5   Cassia alata…………………………………………………………………………...13

2.1.6   Ipomoea involucrata………………………………………………………………….....14

2.1.7   Baphia nitida…………………………………………………………………………..16

2.1.8   Burkea africana………………………………………………………………………..18

2.1.9   Eleusine indica…………………………………………………………………………20

2.1.10   Macrolobium macrophyllum……………………………………………………….…21

2.2.0   Antioxidant activities……………………………………………………….………….22

2.2.1    DPPH Radical Scavenging activities…………………………………………….……22

2.2.2    ABTS Radical Scavenging activities…………………………………………….…....22

2.2.3    Ferric Reducing Antioxidant Power…………………………………………..………22

2.3.0   Antibacterial activities…………………………………………………………............23 

2.3.1   Disc diffusion assay…………………………………………………………….……...23

2.3.2   Minimum Inhibitory concentration (MIC)……………………………………………..23

2.4.0   Thin Layer Chromatographic Profiling………………………………………………...23

CHAPTER THREE

3.0      Materials and Method…………………………………………………………………..25

3.1.0   Plant Sample collection and Identification……………………………………………..25

3.1.1   Extraction……………………………………………………………………………….26

3.1.2   Chemicals and Reagents………………………………………………………….……..26

3.1.3   Bacterial Strain collection………………………………………………………....…….26

3.2.0   Quantification of Phenolic compounds………………………………………….…........27

3.2.1   Determination of total flavonoid content………………………………………….…….27

3.2.2   Determination of total Phenolic acid content……………………………………….…...27

3.3.0   Quantification of Antioxidant activities…………………………………………………28

3.3.1   DPPH (1, 1-Diphenyl-2-picrylhydrazyl) Scavenging assay…………………………......28

3.3.2   ABTS (2, 2-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) Scavenging assay….....29

3.3.3   FRAP (Ferric Reducing Antioxidant Power) assay………………………………….…..30

3.4.0   Antibacterial activity…………………………………………………………………......31

3.4.1   Media Preparation…………………………………………………………………….….31

3.4.2 Disc diffusion method……………………………………………………………….…..32

3.4.3 Minimum inhibition concentration (MIC)…………………………………………..…..32

3.5.0   Thin Layer Chromatography (TLC) Profiling………………………………………...…32

CHAPTER FOUR  

4.0     Result………………………………………………………………………...…………...34

4.1 Description and Biological activities of medicinal plants during the ethno-botanical              survey.34

4.2.0   Antioxidant activities………………………………………………………….………….36

4.2.1  DPPH Assay………………………………………………………….……….…………..36

4.2.2  ABTS Assay………………………………………………………………...………….…37

4.2.3    FRAP Assay……………………………………………………………...……………....38

4.3.0  Determination of polyphenol content…………………………….…………………….....40

4.3.1   Total Flavonoid Content……………………………………………………………..…...40

4.3.2   Total Phenolic Content…………………………………………………….……….….…41

4.4.0    Thin Layer Chromatographic Profiling…………………………………...……...….......42

4.5.0   Antibacterial Activities……………………………………………………….……….….44

4.5.1   Disc diffusion assay……………………………………………………………………....44

4.5.2   Minimum Inhibitory Concentration (MIC)…………………………………………….…47

CHAPTER FIVE

5.1.0    Discussion………………………………………………………………………….…….49

5.2.0   Conclusion………………………………………………………………………………..52

5.3.0   References…………………………………………………………………………….......53

5.4.0   Appendix………