ABSTRACT
Emilia coccinea is a medicinal plant of African origin that belongs to the family of Asteraceae. This plant has diverse and potential medicinal uses in traditional medicine for treating tumor, inflammation, cough, rheumatism, fever, dysentery, wounds and in preventing miscarriage. This study was undertaken to investigate the bioactive constituents, vitamin content, mineral composition and antibacterial properties of methanolic extract of Emilia coccinea leaf. The quantitative phytochemical screening of the extract revealed the presence of alkaloids (3.87 ± 0.02), phenols (0.43 ± 0.01), flavonoids (0.57 ± 0.01), saponins (0.39 ± 0.02), tannins (0.15 ± 0.01) with alkaloid registering the highest presence. Stigmasterol was isolated from the leaves of E. coccinea and was characterized using 1H, COSY, DEPT, HMBC and HSQC NMR Spectroscopic techniques. Vitamins detected included thiamin (0.12 ± 0.01 mg/100g), niacin (0.62 ± 0.05 mg/100g), riboflavin (0.34 ± 0.01 mg/100g), ascorbic acid (5.20 ± 0.80 mg/100g) and β-carotene (3.83 ± 0.05 mg/100g), with ascorbic acid and thiamine having the highest and lowest concentrations respectively. Minerals detected included calcium (27.24 ± 0.01 mg/100g), magnesium (5.42 ± 0.01 mg/100g), potassium (430.20± 0.01 mg/100g), phosphorus (140.36 ± 0.03 mg/100g), nitrogen (3.63 ± 0.07 mg/100g). Of the minerals detected, Phosphorus had the highest concentration, while nitrogen was the lowest. E.coccinea leaves extract exhibited significant free radical activity at minimum and maximum concentrations of 2.0 mg/ml and 12.0 mg/ml compared to the ascorbic acid used as a standard free scavenger These components are known to be medicinal as well as exhibiting physiological activities in humans. The antibacterial activity at varying concentrations of 100 mg/ml, 50 mg/ml, 40 mg/ml, 20 mg/ml and 10 mg/ml of the extract was investigated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa using agar well diffusion method. The results of the antimicrobial assay showed that the extract inhibited the growth of the test organisms in a concentration dependent manner. The highest growth inhibition was seen against B. subtilis and the lowest growth inhibition was against S. aerus with MIC of 5.00±0.00 mg/ml and 35.07±0.71 mg/ml respectively. Thus, the folkloric usage of this plant for the treatment of microbial infections is justified. The results of this research work revealed that Emilia coccinea has a lot of phytochemicals which could be used as raw material by pharmaceutical industries for drug development. The ability of the extract from this plant to exhibit potent inhibition against these pathogens lends a contributory scientific evidence for the use of this plant in traditional medicine.
TABLE OF CONTENTS
Page
Title page i
Declaration ii
Certification iii
Dedication iv
Acknowledgements v
Table of Contents vi
List of
Tables xii
List of
Figures xiii
List of
Plates xii
Abstract
xiii
CHAPTER 1: INTRODUCTION
1.1 Background of the Study 1
1.2 Statement
of the Problem 2
1.3 Justification of the Study 2
1.4 Aim and Objectives of the Study 3
CHAPTER 2: LITERATURE
REVIEW
2.1 Origin and Geographical Distribution of Emilia coccinea 4
2.2 Description of Emilia coccinea 5
2.3 Asteraceae Family 5
2.4 Ethnomedicinal uses of Emilia coccinea 7
2.5 Pharmacological Activity 8
2.5.1 Antioxidant activity 8
2.5.2 Antidiarrhoel activity and anti-microbial
activity
9
2.5.3 Neuroprotective activity 9
2.6 Economic Importance of Emilia coccinea 10
2.7 Chemical Constituents of Emilia coccinea 10
2.8 Phytochemicals 14
2.8.1 Alkaloids 15
2.8.2 Flavonoids 18
2.8.3 Saponins 21
2.8.3 Tanins 23
CHAPTER 3: MATERIALS AND METHODS
3.1 Sample Collection and Preparation 26
3.2 Plant Preparation 26
3.3 Extraction of Plant Material 26
3.4 Column Chromatography 27
3.5 Thin layer Chromatography 28
3.6 Quantitative Phytochemical Determination 29
3.6.1 Determination of alkaloids 29
3.6.2 Determination of tannins 30
3.6.3 Determination of saponins 31
3.6.4 Determination of phenols 32
3.6.5 Determination of flavonoids 32
3.7 Determination of Vitamins 33
3.7.1 Determination of ascorbic acid 33
3.7.2 Determination of niacin 34
3.7.3 Determination of riboflavin 35
3.7.4 Determination of thiamine 35
3.7.5 Determination of β-carotene 36
3.8 Determination of Mineral Elements 37
3.8.1 Digestion of minerals 37
3.8.2 Determination of sodium and potassium by
flame photometry 37
3.8.3 Determination of calcium and magnesium by
complexiometric titration 38
3.8.4 Determination of phosphorus 39
3.9 Determination of Proximate Composition 39
3.9.1 Determination of protein content 39
3.9.2 Determination of crude fibre content 40
3.9.3 Determination of lipid content
41
3.9.4 Determination of moisture content 42
3.9.5 Determination of carbohydrate content
42
3.10 Antioxidant Activity Determination 42
3.11 Antimicrobial Analysis 43
3.11.1 Obtaining and confirming the test organisms 43
3.11.2 Antibacterial susceptibility 43
3.11.3
Determination of minimum inhibitory concentration 44
CHAPTER 4: RESULTS AND DISCUSSION
4.1 Phytochemical Screening Results 45
4.2 Proximate composition of Emilia coccinea 47
4.3 Vitamin Content Results 50
4.4 Mineral Element Composition of Emilia coccinea 52
4.5 Column Chromatography Results 54
4.6 Thin – layer chromatography results 55
4.7 Spectral Analysis Results 56
4.7.1 1H – NMR spectra result 56
4.7.2 2 – Dimensional NMR spectral interpretation 58
4.8 Antioxidant Activity Results 67
4.9 Antimicrobial Assay Results 69
CHAPTER 5: CONCLUSION AND RECOMMENDATION
5.1 Conclusion 72
5.2 Recommendations 72
REFERENCES 73
LIST OF TABLES
4.1 Phytochemical Composition of E. coccinea 45
4.2 Proximate Composition of E. coccinea 47
4.3 Vitamin Composition of E. coccinea 50
4.4 Mineral Elements Composition of E.coccinea 52
4.5 Column Chromatography Result of E. coccinea leaves extract 54
4.6 1H-NMR Chemical Shift for
Fraction A20 56
4.7 DEPT NMR Chemical Shift for Fraction A20 58
4.8 Antioxidant Determination of Crude
Extract from E. coccinea 67
4.9 Zone of Inhibition of Methanolic Extract
of E. coccinea Leaves Extract 69
4.10 Minimum Inhibitory Concentration of E.
coccinea Leaves Extract 69
LIST OF FIGURES
4.1 1H-NMR for Fraction A20 62
4.2 13C (DEPT) NMR for Fraction
A20 63
4.3 1H – 1H – COSY
Spectrum for Fraction A20 64
4.4 1H – 13C HSQC
Spectrum for Fraction A20 65
4.5 1H – 13C HMBC
Spectrum for Fraction A20 66
LIST OF PLATES
Page
Plate
1: Leaves of Emilia coccinea 7
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Plants
which form part of our environment generally have medicinal values. These days,
most plants are languishing in obscurity due to scarcity of information on the
bio-protective properties of these plants. So, the need to study medicinal
plants according to (WHO 1978) cannot be overemphasized for a vista of reasons
including the widespread use of plants in traditional medicine and bringing the
knowledge of plants to the fore as well
as the need for health for all. Since the first earth summit in Rio de
Janneiro, there has been a sustained global awareness on the importance of the
plethora of biodiversity and natural resources from tropical forests for
several purposes (Obute et al.,
2002).
Recent
research studies (Obadoni et al., 2001) have shown that plants are
embodiment of important chemicals, which are bioactive in nature and are mostly
essential to health. Among such groups of chemicals are carotenoids,
flavonoids, vitamins, dietary fibre, minerals, amino acids, prebiotics, etc. Edeoga
et al. (2005) reported that plants derive their medicinal property from
these bioactive chemical compounds.
Yellow
tassel (Emilia coccinea) belongs to
the family Asteraceae. The specie E.
coccinea is an herbaceous plant, annual, weak-stemmed, to 1m high, flowers
solitary, terminal, from Guinea to Nigeria, Cameroon and occurring through eastern
African and into tropical Asia. It is an attractive plant of easy culture with golden-yellow
heads. Emilia coccinea (SIMS)G.DON
commonly known as scarlet tassel flower is
one medicinal plant that has been used traditionally for medicinal purposes to
treat a variety of ailments. E.
coccinea as a lesser known indigenous plant in Nigeria can be refined to
serve as either health supplements or medicinal herbal formula targeted at
treatment of diseases. It is reportedly used in folkloric medicine for the
treatment of tumor, inflammation, cough, rheumatism, fever, dysentery, wounds
and in preventing miscarriage (Ojiako et
al., 2015). The juice of the edible leaves is reportedly used in treating
eye inflammations, night blindness, and ear-aches. Several research works have
been done to study the phytochemical components of Emilia coccinea and also on the antimicrobial activity of the plant
(Nwachukwu et al.,2017).
1.2 STATEMENT OF THE PROBLEM
Emilia coccinea leaves
has been widely used in traditional medicine to cure many ailments in different
parts of the world, such as vertigo, ringworm, gonorrhea, measles, cough,
convulsion etc. (Edeoga et al.,
2005).
However,
most of the compounds responsible for the physiological activities of this
traditional remedy were not known. This has hindered the standardization and
development of this herb and made its recognition, acceptance and utilization
remain locally restricted.
This
necessitated a probe into the isolation and characterization of the bioactive
constituents available in the leaves.
1.3 JUSTIFICATION OF THE STUDY
E. coccinea can
provide an alternative source of antimicrobial drugs. However, it can only be
developed and standardized if its bioactivity is known and its bioactive
principles identified and characterized. Therefore, there is need to
investigate E. coccinea in order to
understand better its chemical composition, properties and efficacy.
This research will provide a database for the active
compounds isolated, the phytochemicals, minerals and vitamins present in the
leaves, as well as the antimicrobial activities of E. coccinea leaves.
1.4 AIM AND OBJECTIVES
This research work is aimed at the
isolation and characterization of secondary metabolites from the leaves of Emilia coccinea. This is to be achieved
through the following objectives:
i.)
To determine the phytochemical,
constituents of E. coccinea
ii.)
To determine the proximate composition of E. coccinea
iii.)
To determine the vitamins
composition of E. coccinea leaves.
iv.)
To determine the mineral
elements composition of E. coccinea.
v.)
To determine the
anti-oxidants and the anti-microbial properties of the leaves of E. coccinea
Login To Comment