ABSTRACT
Coronary artery disease, and its end results myocardial infarction, is a significant cause of morbidity and mortality globally. Recently, there has been an increase in the incidence of myocardial infarction which manifests as a result of disrupted blood supply and oxygen to the myocardium. This present study evaluated the effect of methanol leaf extract of Jatropha tanjorensis on some cardiac function biomarkers in isoprenaline-induced myocardial infarction in albino rats. The in vitro qualitative phytochemical and antioxidant properties of Jatropha tanjorensis leaves were determined using standard analytical methods. Thirty six (36) albino rats were used for the in vivo study and randomly divided into six (6) groups of six rats per group. Group 1 served as the normal control, group 2 was the negative control (administered 85mg/kg of isoprenaline only), group 3 served as the positive control (pretreated with 2mg/kg carvedilol for 28 days), groups 4, 5 and 6 were pretreated with 200, 400 and 600mg/kg of methanol leaf extract of Jatropha tanjorensis respectively, for 28 days. Myocardial infarction was induced in the rats using subcutaneous injection of 85mg/kg isoprenaline (ISO) for two consecutive days (26th and 27th) at 24 hours intervals. The in vitro phytochemical and antioxidant results revealed that Jatropha tanjorensis leaves possess good bioactive compounds such as alkaloids, terpenoids, flavonoids, steroids, tannins, saponins, phenolics and free radical scavenging potency. The acute toxicity study of the extract recorded no death even at the high dose of 5000mg/kg. The result of the in vivo study showed that isoprenaline effectively induced myocardial infarction in rats, reflected by the significant (p<0.05) increases, in the negative control group, of the measured biomarkers (Creatine Kinase-MB activity, Troponin I activity, Lactate Dehydrogenase acitivity, Aspartate aminotransferase activity, Alanine aminotransferase activity, high sensitivity C-Reacting Protein concentration, Triacyglycerol concentration, Cholesterol concentration and Malondialdehyde concentration) relative to the normal control. The extract (400mg/kg) significantly (p<0.05) decrease CK-MB activity, Troponin I activity, LDH acitivity, AST activity, ALT activity, hsCRP concentration, TAG concentration, Cholesterol concentration, and MDA concentration while increasing HDL concentration, catalase activity, SOD activity, GPx activity and GSH concentration. The histopathological study showed different degrees of cardiac alteration. There was marked histomorphological alteration, severe widespread myocardial necrosis of the heart, atrophy of hepatic cord but mild multifocal vascuole degeneration of the renal tubular epithelial lining cell in the group administered 600mg/kg of the extract and the negative control compared to the normal control. This indicated that the extract at 600mg/kg dose does not possess cardioprotective potency. The carvedilol at 2mg/kg dose showed moderate potency in restoring damage cells. The methanol leaf extract of Jatropha tanjorensis at moderate dose (400mg/kg) attenuated the effect of isoprenaline-induced myocardila damage without alteration of the liver and kidney. This study suggested that the extract to some extent could serve as an agent for the prevention of cardiotoxicity.
TABLE OF CONTENTS
Title
page i
Declaration
ii
Certification
iii
Dedication iv
Acknowledgement
v
Table
of Contents vi
List
of Tables xiii
List
of Figures xiv
List
of Plates xv
Abstract xvii
CHAPTER 1: INTRODUCTION
1.1 Background of the Study 1
1.2 Statement of the Problem 3
1.3 Aim and Objectives of the
Study 4
1.3.1 Aim of the study 4
1.3.2 Objectives of the research 4
1.4 Justification for the study 5
CHAPTER 2: LITERATURE
REVIEW
2.1 Myocardial
Infarction 6
2.1.1 Signs
and symptoms of myocardial infarction 6
2.1.2 Causes
of myocardial infarction 7
2.1.3 Mechanism
of myocardial infarction 8
2.1.4 Types
of myocardial infarction 8
2.1.4.1 ST-
elevation myocardial infarction (STEMI) 9
2.1.4.2` Non-ST
elevation myocardial infarction (NSTEMI) 9
2.1.4.3 Unstable
angina 9
2.1.4.4 Myocardial infarction type 1 9
2.1.4.5 Myocardial
infarction type 2 10
2.1.4.6 Myocardial
infarction type 3 12
2.1.4.7 Myocardial
infarction type 4a 12
2.1.4.8 Myocardial
infarction type 4b 12
2.1.4.8 Myocardial
infarction type 4c 13
2.1.4.9 Myocardial
infarction type 5 13
2.2 Biomarkers
for Evaluation of Myocardial Infarction 13
2.2.1 Creatinine kinase MB (CK-MB) 14
2.2.2 Troponin 14
2.2.3 Aspartate amino transferase (AST) 14
2.2.4 Lactate dehydrogenase (LDH) 15
2.2.5 Heart fatty acid‑binding protein (H‑FABP). 15
2.2.6 Myoglobin: 15
2.3 Incidence
and Prevalence of Myocardial Infarction 16
2.4 Diagnosis
and Management of Myocardial Infarction. 17
2.5 Free Radicals and Oxidative
Stress 18
2.5.1 Mechanism of reaction of free radicals and
oxidative stress 18
2.6 Role
of Oxidative Stress in Cardiovascular Diseases 19
2.6.1 Oxidative
stress and hypertension 19
2.6.2 Oxidative
stress and heart failure 20
2.6.3 Oxidative
stress and myocardial ischemia reperfusion injury 21
2.7 Overview of Jatropha
tanjorensis 23
2.8 Pharmacological Properties of
Jatropha
tanjorensis 24
2.8.1 Hepatoprotective effect 24
2.8.2 Antioxidant
24
2.8.3 Antidiabetic
effect 24
2.8.4
Anticancer effect 24
2.8.5 Antianaemic
effect 25
2.8.6 Anti-ulcer
effect 25
2.8.7 Phytoconstituent
of Jatropha tanjorensis 25
2.8.8 Hypolipidemic
activity 26
2.8.9 Antibacterial
effect 26
2.9 Cardioprotective
Properties of Some Medicinal Plants 26
2.9.1 Moringa
plant 26
2.9.2 Vernonia
amygdalina 27
2.9.4 Garcinia
kola 28
2.9.5 Anarcadium
occidentale 28
2.9.6 Mucuna
puriens 29
2.9.7 Zingiber
officinale 30
2.9.8 Allium
sativum 30
2.9.9 Allium
cepa 31
2.9.10 Curcuma
longa 32
2.9.11 Hibscus
sabdariffa 33
CHAPTER 3: MATERIALS
AND METHODS
3.1 Materials 34
3.1.1 Collection of plant leaves 34
3.1.2 Chemicals/reagents used 34
3.2 Methods 34
3.2.1 Extract preparation 34
3.2.2 Phytochemical
screening 35
3.2.2.1 Test
for alkaloids 35
3.2.2.2 Test for steroids 35
3.2.2.3 Test for flavonoids 35
3.2.2.4 Test for tannins 35
3.2.2.5 Test for saponins 35
3.2.2.6 Test for terpenoids 36
2.2.2.7 Test for phenolics 36
2.2.3 In
Vitro Antioxidants 36
3.2.3.1 Determination of total phenol content 36
3.2.3.2 Determination of total flavonoid content 37
3.2.3.3 Determination of hydrogen peroxide scavenging
capacity 37
3.2.3.4 Determination of reducing power 38
3.2.3.5 Determination of nitric oxide (NO) scavenging
activity 38
3.2.3.6 Determination of lipid peroxidation assay 39
3.2.4 Experimental
animals 39
3.2.5 Acute
toxicity test (LD50) 39
3.2.6 Experimental design 40
3.2.7 Biochemical estimations 41
3.2.7.1 Assay of alanine amino transferase (ALT)
activity 41
3.2.7.2 Assay of serum aspartate aminotransferase (AST)
activity 42
3.2.7.3 Lactate
dehydrogenase (LDH) activity 43
3.2.7.4 Determination
of CK-MB activity 43
3.2.7.5 Determination
of high sensitivity c-reactive protein
(hsCRP) 44
3.2.7.6 Determination
of troponin level: 46
3.2.8 Antioxidant estimation in serum 47
3.2.8.1 Estimation of extent of lipid peroxidation 47
3.2.8.2 Assay of superoxide dismutase activity 48
3.2.8.3 Assay
for catalase activity 48
3.2.8.4 Estimation of glutathione peroxidase activity 49
3.2.8.5 Reduced glutathione estimation 50
3.2.9 Lipid
profile tests 51
3.2.9.1 Determination
of serum total cholesterol 51
3.2.9.2 Determination
of serum triacylglycerol concentration 52
3.2.9.3 Determination
of serum high density lipoprotein-cholesterol concentration54
3.2.10 Organ weight to body weight ratio 55
3.2.11 Histopathological examination 55
3.2.11.1 Tissue preparation 55
3.2.11.2 Slide examination 56
3.3 Statistical
analysis 56
CHAPTER
4: RESULTS AND DISCUSSION
4.1 Results 57
4.1.1: Phytochemicals present in methanol extract of Jatropha
tanjorensis leaves57
4.1.2: Total (phenols and
flavonoids) content and in vitro IC50 values of
antioxidants 58
4.1.3 Reducing power of Jatroph tanjorensis. 59
4.1.4: Nitric oxide (NO) scavenging ability of Jatropha
tanjorensis 60
4.1.5: Hydrogen
peroxide (H2O2) scavenging ability of Jatropha
tanjorensis 61
4.1.6: Lipid peroxidation ability
of Jatropha tanjorensis. 62
4.1.7: Acute toxicity study of
methanol extract of Jatropha tanjorensis leaves 63
4.1.8: Effect
of methanol leaf extract of Jatropha tanjorensis on body weight and
organ weights 64
4.1.9: Effect of methanol leaf
extract of Jatropha tanjorensis on serum troponin
activity 65
4.1.10: Effect of methanol leaf extract of Jatropha
tanjorensis on serum CK-MB
activity 66
4.1.11: Effect of methanol leaf extract of Jatropha
tanjorensis on serum LDH
activity 67
4.1.12: Effect of methanol leaf
extract of Jatropha tanjorensis on serum hsCRP
concentration. 68
4.1.13: Effect of methanol leaf extract of Jatropha
tanjorensis on serum AST
concentration. 69
4.1.14: Effect of methanol leaf extract of Jatropha
tanjorensis on serum ALT
concentration. 70
4.1.15: Effect of methanol leaf
extract of Jatropha tanjorensis on serum TAG
concentration. 71
4.1.16: Effect of methanol leaf extract of Jatropha
tanjorensis on serum
total
cholesterol concentration. 72
4.1.17: Effect of methanol leaf
extract of Jatropha tanjorensis on serum HDL
concentration. 73
4.1.18: Effect of methanol leaf extract of Jatropha
tanjorensis on serum SOD
activity. 74
4.1.19: Effect of methanol leaf extract of Jatropha
tanjorensis on serum GPx
activity. 75
4.1.20: Effect of methanol leaf extract of Jatropha tanjorensis
on serum glutathione
concentration. 76
4.1.21: Effect of methanol leaf extract of Jatropha
tanjorensis on serum catalase
activity. 77
4.1.22: Effect of methanol leaf extract of Jatropha
tanjorensis on serum MDA
concentration. 78
4.1.23: Histopathological
analysis 79
4.2 Discussion 85
CHAPTER 5: CONCLUSION AND RECOMMENDATIONS
5.1 Conclusion 93
5.2 Recommendation 94
References
Appendices
LIST
OF TABLES
PAGE
4.1 Phytochemicals present in
methanol extract of Jatropha tanjorensis leaves 57
4.2: Total (phenols and
flavonoids) content and in vitro IC50 values of
antioxidants 58
4.3: Acute
Toxicity Study of methanol extract of Jatropha tanjorensis leaves 63
4.4: Effect
of methanol leaf extract of Jatropha tanjorensis on body weight and
organ weights 64
LIST
OF FIGURES
PAGE
4.1 Reducing power of Jatroph
tanjorensis. 59
4.2: Nitric
oxide (NO) scavenging ability of Jatropha tanjorensis 60
4.3: Hydrogen
Peroxide (H2O2) scavenging ability of Jatropha
tanjorensis 61
4.4: Lipid peroxidation ability
of Jatropha tanjorensis. 62
4.5 : Effect of methanol leaf extract of Jatropha tanjorensis
on serum troponin
activity 65
4.6: Effect of methanol leaf
extract of Jatropha tanjorensis on serum CK-MB
Activity. 66
4.7: Effect of methanol leaf
extract of Jatropha tanjorensis on serum
LDH activity 67
4.8: Effect of
methanol leaf extract of Jatropha tanjorensis on serum
hsCRP
concentration 68
4.9: Effect of methanol leaf
extract of Jatropha tanjorensis on serum
AST
concentration. 69
4.10: Effect of methanol leaf extract of Jatropha
tanjorensis on serum ALT
Concentration. 70
4.11: Effect of methanol leaf
extract of Jatropha tanjorensis on serum TAG
concentration 71
4.12: Effect of methanol leaf extract of Jatropha
tanjorensis on serum total
cholesterol
concentration 72
4.13: Effect of methanol leaf
extract of Jatropha tanjorensis on serum HDL
Concentration. 73
4.14: Effect of methanol leaf extract of Jatropha
tanjorensis on serum SOD
activity 74
4.15: Effect of methanol leaf extract of Jatropha
tanjorensis on serum GPx
activity 75
4.16: Effect of methanol leaf extract of Jatropha
tanjorensis on serum
glutathione
concentration 76
4.17: Result on the effect of methanol leaf
extract of Jatropha tanjorensis on
serum catalase
activity 77
4.18: Effect of methanol leaf extract of Jatropha
tanjorensis on serum MDA
Concentration. 78
LIST OF PLATES
PAGE
A-C Sections of the heart, liver and kidney from normal
(control) rats 80
A-C: Sections of the heart, liver and kidney from rats given distilled
water and isoprenaline (85mg/kg) 81
A-D: Sections of the heart from the pretreated
groups 82
A-D: Sections of the liver from the pretreated
groups 83
A-D: Sections
of the kidney from the pretreated groups 84
CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Globally, there is increase in the number
of deaths resulting from the generation of free radicals and oxidative stress.
Metabolic pathways and environmental pollution easily generate free radicals
which are also regarded as reactive species (Souri et al., 2008; Neha and Lubna, 2014). Different factors can elevate
and accumulate the level of oxidative stress and free radicals which easily
prevent the cell from working effectively. This can then lead to damage of
cells, and has main contributory role in pathogenesis of cardiovascular
diseases (Mohanty et al., 2007;
Mahammad et al., 2012).
According
to the American Heart Association and World Health Organization statistics, cardiovascular
diseases (CVDs) are regarded as the main cause of death worldwide (Mozaffarian et al., 2016). CVD
mostly refers to MI (Myocardial infarction), angina pectoris, hypertension,
stroke and other circulatory diseases. Coronary artery diseases, congestive
heart failure, cardiac arrest, arrhythmias, and peripheral artery diseases are
the most commonly reported heart diseases (Mallapu et al., 2017).
A coronary artery disease which is
also called Ischemic heart disease is a crucial problem worldwide and is known
as major non transmissible disease (Abubaker
et al., 2012). A good example
of ischemic heart disease is acute myocardial infarction (MI) and it manifest
due to inequality between coronary blood supply and myocardial demand.
Myocardial damage due to free radicals is an imperative etiological mechanism
that is linked with increased level of reactive oxygen species and/or
insufficient antioxidant defense system (Geeta et al., 2016). Isoprenaline (ISO) is a synthetic catecholamine with
active effect on non-selective beta-adrenergic agonist and low affinity for
alpha adrenergic receptors. It has the tendency to produce myocardial lesions
and cell death at high doses. Various drugs with cardioprotective effects such
as bisoprolol, metoprolol, carvedilol and timolol have been studied using
isoprenaline-induced myocardial infarction model. However the adverse effect
associated with modern medicines have limited their effective used in
preventing heart diseases (Upaganlawar et al., 2011).
Leafy vegetables play vital role in
the food culture of many African households and it is part of Africans’
cultural heritage (Mensah et al., 2008; Omoregie et al., 2011). Nigeria is blessed with a multiplicity of indigenous
green leafy vegetables which are consumed by various groups for different
purpose (Omoregie et al., 2011). Medicinal plants are unique in their
ability to treat several human ailments because they contain various valuable
phytoconstituents. Secondary plant metabolites such as steroids, alkaloids,
flavonoids, glycosides, terpenoids, tannins, saponins, phenolic compounds etc.
are mainly accountable for the healing potency of the plant (Omoregie
et al., 2011).
Medicinal plants have been used for
centuries to combat many health challenges and are also useful component in
pharmaceutical industries; among these leafy vegetables is Jatropha
tanjorensis. Jatropha tanjorensis
known as Chaya leaf and generally known as ‘Hospital too far’ in Nigeria is a
shrub from the family Euphorbiaceae. Different parts of Jatropha plants
are used in many ways and in different countries.
Jatropha tanjorensis
leaves have been reported to possess numerous medicinal properties such as
hepatoprotective (Ezeonu et al., 2017;
Madubuike et al., 2015), antidiabetic
(Momoh et al., 2014; Chinenye et al., 2019), anticancer (Purshothaman et al., 2014), antianaemic (Ameloko
2010; MacDonald et al., 2014),
antiulcer (Epison et al., 2016),
hypolipidemic (Oyewole and Akingbala, 2011; Ijioma et al., 2014), antioxidant (Omoregie et al., 2011),
antibacterial (Oboh and Masodje, 2009; Daniyan et al., 2018) among others.
1.2 STATEMENT OF THE PROBLEM
The Prevalence of myocardial infarction as
the leading cause of death worldwide is a public health challenge. Myocardial
infarction is a disorder in which there is myocardial cell necrosis due to
substantial and persistent ischaemia. It is usually, but not always an acute
manifestation of atherosclerosis-related coronary heart diseases, which implies
obstructing mechanisms (Mendis, et al., 2011).
The most prominent causes of myocardial infarction are ischemic heart
disease/coronary artery disease resulting from an obstruction in blood flow
leading to an inequality in myocardial oxygen supply (Mulqueen, 2015).
Atherosclerotic disease generally accepted as coronary artery disease can lead
to sudden formation of a blood clot on top of plaque that reduces blood flow in
an already narrowed vessel (Steinbaum, 2017; Cleaveland, 2019).
There is a link between inflammation
and evolution of heart attack. The inflammation of the coronary artery walls
over time increases the accumulation of fatty plaques. Several cardiovascular disease risk factors
can result to the manifestation of myocardial infarction. Cardiovascular
disease (CVD) is regarded as the major cause of mortality and disability in
advanced countries (Mozaffarian et al.,
2016). Further, the frequent rise in
common risk factors for CVD and the metabolic syndrome, have necessitated the
search for more effective approaches to prevent and treat these cardiometabolic
disorders (Koren et al., 2011).
Consumption of natural antioxidants has been reported to contribute in the
reduction of cardiovascular disease. Plants, herbs and spices rich in phenolic
compounds are known to have pharmacological activities which can be traced to
their antioxidant properties (Ashok-kumar et al., 2008; Madubuike et al., 2015).
Many studies have reported the antioxidant,
anti-inflammatory, antibiotic, antihypertensive, antispasmodic, antiulcer,
hypoglycemic and hypocholesterolemic activities of Jatropha tanjorensis
(Bais et al., 2014).
Been that very few publications have
been reported about the myocardial beneficial effect of Jatropha tanjorensis, the present study will evaluate whether Jatropha tanjorensis leaves extract has
cardioprotective effect against ischemic myocardial infarct model in albino
rats.
1.3 AIM AND OBJECTIVES OF THE STUDY
1.3.1 Aim of the study
The aim of this study was to evaluate
the effect of methanol leaf extract of Jatropha tanjorensis on some
cardiac function biomarkers in isoprenaline induced myocardial infarction in
albino rats.
1.3.2 Objectives of the study
The objectives of this study were:
(i)
To determine qualitative
phytochemical constituents of the plant extract.
(ii)
To determine the in-vitro and in vivo (superoxide
dismutase, catalase, glutathione peroxidase, reduced glutathione and MDA)
antioxidant properties of Jatropha
tanjorensis leaf.
(iii)
To determine the median
lethal dose (LD50) of the methanol extract of Jatropha tanjorensis leaf.
(iv)
To determine the effects
of the methanol leaf extract of Jatropha
tanjorensis on some cardiac biomarkers (Troponin I, Creatine kinase-MB, LDH,
AST, ALT, hsCRP) activity in albino rats.
(v)
To determine the effects
of the methanol leaf extract of Jatropha
tanjorensis on some lipid profile (TAG, HDL, Cholesterol) concentration in
albino rats.
(vi)
To carry out histological
studies on the heart, liver and kidney of the experiment animals
1.4 JUSTIFICATION FOR THE STUDY
The present investigation is a
continuation of the research efforts aimed at providing the requisite
scientific information and empirical data on the therapeutic value,
toxicological potential and active principles of Nigerian medicinal plants as
used in the management and treatment of several ailments. Jatropha tanjorensis leaf has recently received a lot of attention
for both its nutritional and antioxidant properties and several researchers
have shown that Jatropha tanjorensis possesses
hypoglycemic, hypolipodermic, antioxidant and antimicrobial properties among
others. The present study is designed to validate the ethnomedicinal use of Jatropha tanjorensis leaves using
methanol as the solvent for extraction. This will also serve as a basis to
recommend the continuous use of the plant in ethnopharmacology.
Click “DOWNLOAD NOW” below to get the complete Projects
FOR QUICK HELP CHAT WITH US NOW!
+(234) 0814 780 1594
Login To Comment