THE EFFECTS OF HERBAL MIXTURE ON FERROUS CHLORIDE-INTRODUCED LIVER TOXICITY IN THE ADULT WISTAR RAT

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CHAPTER ONE
INTRODUCTION
Background to the study
Haemochromatosis is the clinical manifestation of iron overload and indicates accumulation of iron in the body which could be hereditary or secondary (acquired). The most important causes are hereditary haemochromatosis from transfusional iron-storage diseasewhich could result from continual blood transfusions (Hider et al., 2013; Luet al., 1994). Secondary haemochromatosis is from blood meal which provides high levels of iron as ferric-transferrin and as hemoglobin in erythrocytesand lots of red meat (Geiser et al., 2006; Pham and Chavez, 2005; Dunkov et al., 2002). Organs commonly affected by haemochromatosis are the heart, liver and endocrine glands(Andrews, 1999).
According to John (2007), haemochromatosis may present the following clinical syndromes: cirrhosis of the liver which varies from fibrosis to zonal iron deposition (Lu, 1995), diabetes (Lu, 1995), cardiomyopathy, arthritis which is due to calcium pyrophosphate deposition in joints(Bruce and Stanley, 2016), testicular failure and deep tan color of the skin with insulin insufficiency due to pancreatic damage which gives rise to bronze diabetes.
Haemochromatosis as introduced by von Recklinghausen at the end of the 19th century is referred to as the clinical disorder that results from excess total body iron and organ failure due to iron toxicity. Sources of iron toxicity includes iron in the water, iron in supplements or occupational exposure, excessive absorption of iron from the diet and the inability to eliminate enough iron from the body which can be due to physical or mental factors (Simon et al., 1977).Iron is most available to the body when chelated to amino acids (Pineda and Ashmead, 2001) and is also available for use as a common iron supplement.
Iron overload (Haemochromatosis) is a metal related toxicity that may be caused by defects in iron absorption. This could occur from repeated blood transfusions in dependent anaemias such as sickle cell anaemia and β-thalassemia. It could also be in pathological conditions where there is high absorption of iron from diets or from the consumption of blood meals or lots of red meat. The destruction of liver cells as well as cell death can result from excess iron and scarring of the liver may develop leading to a condition called cirrhosis which may be fatal. The deoxyribonucleic acid (DNA) of the liver cells and the high risk of developing liver cancer can be caused by excess iron. However, iron-induced oxidative stress and several human diseases is associated with excess iron.
An imbalance between reactive oxygen species and the ability of a biological system to detoxify the reactive intermediates or repair subsequentdamage is termed oxidative stress. Oxidation takes place as the body metabolizes the oxygen that is inhaled and the cells generate energy from it. Oxidation is increased on exposure to stress, toxins and infections. It is also accumulated by sugar and chemicals. The more anti-oxidants consumed, the better the counteringof oxidation process and prevention of oxidative stress. Research indicates herbs as good sources of anti-oxidants for oxidative stress(Donielle, 2014).
Oxidative stress is suspected to be very important in neurodegenerative diseases, depression and sclerosis (Patel and Chu, 2011).Oxidative stress is also linked to certain cardiovascular dysfunctions, since oxidation of low-density lipoprotein in the vascular endothelium is a precursor to plaque formation. Due to oxygen reperfusion injury, oxidative stress is involved in ischemic cascade as well following hypoxia, strokes and heart attacks. Oxidative stress occurs in chronic fatigue syndrome(Nijs et al., 2006)andalso contributes to tissue injury following irradiation and hyperoxia, as well as in diabetes.
Medicinal plants have been described as plants in which their constituents contain substances which can be used for therapeutic purposes or which are precursors for the synthesis of useful drug (W.H.O, 2006). The use of natural plants locally for primary health remedies is a common practice in Africa, Asia and Latin America(Bibitha et al., 2002). Although several plants are consumed as food without an in-depth knowledge of their exact chemical composition and contribution to health, their utilization through several generations seem to justify their use (Ghani et al., 1989).
Use of plant extracts or their active principle may serve as source of new drugs or sources of intermediate compounds for synthesizing analog drugs (Akerele, 1993). Extracts from plants are always sought for as effective and less expensive alternative sources of medication all around the world especially in developing countries. Useful spices and herbs like garlic (Allium sativum), bitter leaf (Vernonia amygdalina), ginger (Zingiber officinale), scent leaf (Ocimum gratissimum), which are indigenous to Africa have been reported to enhance the performance of livestock animals (Mohammed et al., 2007).
Vernonia amygdalina commonly called bitter leaf because of its bitter taste is consumed either as tonics for the treatment of various illnesses or as a vegetable for cooking African soups (Imaga and Bamigbetan, 2013). The bitter taste has been thought to be as a result of the presence of tannins, alkaloids, glycosides and saponins as shown by various authors to be present in bitter leaf (Butler and Bailey, 1973; Ologunde et al., 1992; Bonsi et al., 1995). The root of V. amygdalina has been used for toothache and gingivitis (periodontitis) owing to its established antimicrobial activity (Huffman et al., 1993). In Nigeria,V. amygdalina is the most historically and traditionally used anti-diabetic herb (Gbolade, 2009).
Ocimum gratissimum is commonly known as scent leaf and has a distinctive smell and taste. It contains the following nutritional and medicinal components: protein, magnesium, carotenoids, moisture, zinc, phosphorus, selenium, iron, fiber, vitamin C, folate, vitamin A, calcium, energy and lipids. Ocimum gratissimum has been known to provide various medicinal and culinary properties. These medicinal properties exert bactericidal (antiseptic) effects on some bacteria. It possess antifungal activity againstPenicillium notatum,Candida albicans, Microsporeum gyseum and larvicidal activity against mosquitoes, houseflies and other insects. The above effects have been attributed to the major components in this plant which includes flavonols, phenols, alkanoids, essential oils, and peptides (Okigbo and Igwe, 2007).
The part of the plant used for treatment is the whole herb which includes the flower, stalk, leaf, stem, seeds and essential oils. Ocimum gratissimumis also able toforestall cancer and reducecholesterol. Scent leaf medicinaladvantagesinclude the scent leaf extract utilized incontrollingblood glucose level. In diabetes mellitus, particularly non-insulin dependent (NID diabetes), scent leaf may lower blood sugar levels and protect the pancreatic cells that produce insulin from damage.
Allium sativumwhich is widely known as garlic is a vegetable that belongs to the Allium class of bulb-shaped plants. Garlic is unique because of its high sulfur content and it is used for flavouring in cooking. Garlic contains sulfur in addition to oligosaccharides, flavonoids, arginine, and selenium, all of which are beneficial to health (Milner, 1996). The distinct flavour and odour of garlic comes from sulfur compounds fashioned from allicin, the main precursor of garlic’s bioactive compounds which are formed when garlic bulbs are chopped, crushed or damaged (Ross et al., 2006). Some animal and human studies recommend that garlic will lower blood sugar levels and increase insulin.
The National Cancer Institute recommends garlic as a vegetable with potential anticancer properties (Hsing et al., 2002).Garlic is simple to grow. It is efficient and helps to manageblood glucose levels, potentially stop or reducethe consequences of some diabetes complications, fight infections, reducelow densitylipoproteincholesterol and encourage circulation (Jamieson, 2003).
Zingiber officinale commonly known as ginger is a rhizome and is commonly found in most Nigerian homes where a small percentage of its flour (not more than 10 percent) is used mainly as a spice for flavouring a variety of dishes and drinks. Ginger has been identified as a herbal medicinal product with pharmacological effect. Ginger has been reported to be used in traditional medicine by other countries of the world in the management of diabetes (Al-Amin et al., 2006), a greater percentage of the Nigerian population are unaware of this. Ginger has been shown to possess anti-diabetic activity in a variety of studies. Akhani et al (2004) reported that ginger pretreatment inhibited induced hyperglycemia and hypo-insulinemia. It has been shown that Ginger improves various heart disease risk factors in patients with type 2 diabetes and lowers blood glucose levels.
Curcuma longa commonly called Turmeric is a rhizome and a yellow-orange spice. It has an orange pulp contained inside the rhizome which constitutes the source of turmeric medicinal powder (Chainani-Wu, 2003). The vital constituents of Curcuma longa are curcumin, flavonoid, various volatile oils including zingiberone, atlantone and tumerone and; other constituents like proteins, sugars and resins.
Curcumin is the most researched active constituent which comprises 0.3 to 5.4 percent of raw Turmeric. When given orally, a high percentage (40 to 85 percent) of curcumin goes through the gastrointestinal tract without being changed, with most of the absorbed flavonoid being metabolized in the liver and intestinal mucosa.
Protective effects of Turmeric on the cardiovascular system include decreasing susceptibility of low density lipoprotein to lipid peroxidation (Ramirez-Tortosaet al., 1999), lowering cholesterol and triglyceride level and inhibiting platelet aggregation (Srivastava et al., 1986). These effects have been noted even with low doses of Turmeric.
Statement of the problem
The liver is a vital organ that plays a major role in human metabolism. Based on its peculiar structural and functional anatomy, it is highly susceptible to the influence of a wide variety of injurious agents including toxins and infections (Nwokediuko etal., 2013).In Nigeria most people consume several mixtures of medicinal plants either by the recommendation of a friend, family member or a relation without indept knowledge of the constituents of the mixture. It is believed to be medicinal for various diseases and infections like malaria, tyhphoid, diarrhea, diabetes amongst others. It is taken in different doses. Some persons take one glass cup a day in the morning, others take two glass cups a day in the morning and evening while few take three glass cups a day in the morning, afternoon and evening. The constituents of the mixtures varies as preferred and recommended by different persons for different uses.The curiocity of knowing the constituents, effectiveness and to ascertain if there are side effects to the consumption of medicinal plant mixtures led to this research which consisted of a mixture of bitter leaf, scent leaf, garlic, ginger and turmeric used by some person for the treatment of diabetes.
Aim and objectives of the study
The aim of this study was to evaluate the effects of the herbal mixture on ferrous chloride-induced liver toxicity in the adult Wistar rat.

THE EFFECTS OF HERBAL MIXTURE ON FERROUS CHLORIDE-INTRODUCED LIVER TOXICITY IN THE ADULT WISTAR RAT