ABSTRACT

The antidiabetic effect of bitter leaf soup with garri on blood glucose and growth performances of type 1 streptozocin induced rats was evaluated in this work.The effect of bitter leaf soup was investigated against type 1 streptozocin induced diabetic rats. The phytochemical screening of this plant revealed the presence of the following; Alkaloids, glycosides, tannins, saponins, and reducing sugar. The observation from this work shows that bitter leaf soup could be used as a natural supplementary herbal remedy for diabetes.

Key words: Diabetes, bitter leaf soup, garri and streptozotocin

CHAPTER ONE

INTRODUCTION

1.1    Background Information

Plant has long been used as traditional remedies for the treatment of diabetes in many part of the world.[Kupchan,1971; Wambebe and Again 1990]. In the present times, available evidences suggest a high prevalence of utilization of alternative Medicine for the treatment of diabetes in some regions of the word. The use of teas prepared from several plants in wide spread Elisabetsky, (1987) and some of these teas are used as remedies in diabetes. Medical plant has been applied to human health for thousands of years. During discovery times was largely by chance and based on clinical practices [Sofowora, 1993]. As understanding of therapeutic benefits deepens and demands for medicinal plants diseases. Modern drugs screening involves sequencial testing for any new chemical entities [NCEs] or extract from herbal sources by invitro experiment and conducted in lower animals like mice and rats and also in higher animals if necessary. Most drugs used in therapy nowadays have been found and evaluated with specific structures and pharmacological effects [Wang, 2005]. In spite of the presence of known antidiabetic medicines in the pharmaceutical market, remedies from medicinal plants are used with saucers to treat this disease possibly they are consider to be less toxic, produce fewer side effects and are relatively inexpensive as compared to synthesis  anti-diabetic agents[ monim, 1997]. Ethno botanical information indicates that, more than 800 plants are used as traditional remedies for the treatment of diabetes [pushparraj et al., 2000], but only a few have received scientific scrutiny. The world health organization (WHO) has recommended the evaluation of the effectiveness of plant in conditions that were safe. Orthodox drugs are scarce (WHO, 1980).Many studies have confirmed the benefits of medicinal plants to hypoglycemic effects in the management of diabetes mellitus. The effects of these plants may delay the development of diabetes complication and even assist in correcting the metabolic abnormalities.  Moreover, during the past decade and especially in the last few years. Therefore, plants can be used to treat disbetesmellitus (Li,Bujuru and Dekimpe,2004).

1.2 Health Importance of Bitter Leaf

Bitter leaf is a traditional ingredient in many African soups. Also known as vernoniaamydalia, its bitter taste makes it distinct from many other ingredients used for preparing soups. Bitter leaf helps to reduce blood sugar level. The crude chloroform extract of the bitter leaf has antidiabetic effects in rats with diabetes mellitus under laboratory conditions. Pharmacy and bioresources, (2005) researches writing in the medical journal of Islamic world Academy of sciences said that the administration of aqueous extract of bitter leaf at a concentration of 500mg/kg of body weight significantly decreased the level of blood glucose. Its efficacy to lower blood glucose level was comparable with that of chlorpropamide, a standard drug used in the management of diabetes.

1.2      Treatment of Stomach Ache

In cases of constipation, stomach ache and inflammation of the stomach, bitter leaf is the remedy (Sowofora, 2006). The extract from the raw leaf of bitter leaf is an antidote for malaria (P. Ernest, 2004). Common skin infection such as ringworm, eczema and others have been successfully treated with bitter leaf coupled with the drinking of the fresh bitter leaf juice. This clears the skin in no time because of its antimicrobial effects. (Oguntola, 2015).

Bitter leaf protects the liver from drug induced damage by eliciting protection against liver damage through its antioxidant (prevent cell death). It also inhibits breast cancer if incorporated in the diet, can slow cancer growth and can even kill cancer cells (Ernest B., 2014).

1.2.1        Medicinal Plants Used in the Treatment of Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterize disturbance in carbohydrate, protein and lipid and by complications like retinopathy,microangiopathy and neuropathy (Akhtar and Ali, 1980). It is due to reduced insulin action or insulin deficiency (Akahetal., 2002).

There is increased incidence of diabetes in recent years (Wokoma, 2002). According to Wokwma, this increased incidence coincides with the transformation of African societies of European type industrialized andsedentary urban life-style. About halfof these people are living in countries without access to orthodox medicines, and herbal alternatives are widely used, the used of herbal alternatives to range factors including policy makers and researchers (kokum and Grison, 2007).

The WHO recommended the search for beneficial use of medicinal plants for the treatment of diabetes mellitus (WHO, 1985). Herbal alternatives are derived from medicinal plants. By Definition, a medicinal plant is any plant which one more of its organs, contains a substance that can be used for therapeutic purpose which is a precursor for the synthesis of useful drugs (sofowora, 1993). The WHO defines a medicinal plant as that which possesses therapeutic properties or exerts beneficial pharmacological effects on the animal body. There are no apparent morphological characteristic in medicinal plants growing with name but the anti- diabetic effects of these plants are attributed to their ability to restore the function of pancreatic tissues by causing an increase in insulin output or inhibit the intestinal absorption of glucose or the facilitation of metabolites of insulin dependent processes.

1.2.2        Hypoglyceamic Plants

marvalsEaglemarvals(L) The roots and fruits of eagle marvels (L) (Rulaceae) are used in Ayuruedic medicine for treatment of various ailments (Raoet al., 2002) fresh leaves of Eagle marvels collected in Pondicherry (India) were found to have two distinct taste sweet and bitter.Base on the characteristic taste observed, these two are considered as two varieties of aeglemarmelos with hypoglycemic activity (Raoet al., 2002), In comparative evaluation of hypoglycemic activity of the leaf extracts of these two varieties, made in normal rabbits, it was discovered that the ethanol extracts of the leaves of sweet and bitter varieties of Aeglemarmelos produced hypoglycemic activity in a dose dependent manner. From the result obtained, the bitter variety had more pronounced hypoglycemic activity than the sweet variety and the compounds may produce direct or indirect hypoglycemic activity. The observed differences in the hypoglycemic activity of the two varieties may be due to the possible variability in the chemical composition (Raoet al., 2002).

1.2.3        Parinari polyandra (rosaceae)

Parinari polyandra is a plant commonly found in the savannah rainforest and open grassland. It yields an excellent charcoal used by blacksmiths in Niger state, Nigeria. The cold preparation of hot water infusion of the stem bark is used in the treatment of diabetes mellitus in experimental rats, the methanol stem bark extract of parinari polyandra showed hypoglycemicactivity (Vongtau et al.,1997).

The extract administered orally caused a slight fall in fasting plasma level of normoglycaemic rats and significantly lowered the plasma glucose level in streptozocin diabetes rats (Vongtau etal., 1997).

1.2.4        Magnifera indica (ancardiceae)

Magnifera indica also referred to as mango” in English and its population as an anti-diabetic in Brazil.An estimated 5% of diabetic patients were found to be using mango as a presumed hypoglycemic treatment (Teaeira, 2000). In an earlier study, Rahaman and Zaman reported the hypoglycemic activity of mangnifera indicia (RahamanandZaman, 1998). A recent investigation has however revealed that an infusion of the leaves of this plant did not exhibit hypoglycemic effect in normal and streptozocin induced diabetes in rats and also in healthy volunteers in whom it was administered a delirium (Teaeira, 2000).

1.2. 5   Scope of the Study

This study will be limited to the following

i.     Collection and identification of the plants.

ii.    Weighing of the rats to be used.

iii.   Grouping of the animals.

iv.   Preparation of the swallow, a mixture of bitter leaf soup with garri

v.   Treatment of the rates with the swallow.

vi.  Determination of blood glucose levels

vii. Collection of blood by cardiac puncture from anaesthetised rates treated with the swallow

viii. Determination of sorum lipid

1.2.6   Dioscoreadumentorum(Dioscreaceae)

The extract of the tubers have been employed to treat diabetes mellitus in Africa traditional medicine (Iwu, 1982). Investigations have shown that the crude extracts of the plant produced remarkable hypoglycaemic effect in normal rats as well as steptozocin induced diabetic rats (Undiesand Abuse, 1986). The hypoglycaemic principle, isolated from the tubers (Iwuet al., 1990) has shown to be effective in lowering blood sugar levelin both normal and STZ induced diabetics rats(Iwu et al.,1990) .

1.2.7 Botany of Vernonia amygdalina

Domain                    Eukayota

Kingdom                  Plantae – plant

Phylum                     Vascular plant

Class                         DiCotyledons

Order                        Asterales

Family                       Asteraceae

Genus                        Vernonia

Species                      V. amygdalina

1.2.8        Hepatoprotective Effects of Ethanolic Leaf Extracts of Vernonia Amygdalina.

Liver is the major organ for detoxification and removal of endogenous substances. It is continuously and widely exposed to hepatotoxins, xenobiotic substances and chemotherapeutic agents that lead to impairment of its functions (Toxicol, 2007).

Liver diseases are mainly caused by excess consumption of alcohol, toxic chemicals, infections and autoimmune disorders (Toxicol, 2007). Liver diseases often progress from subclinical uteric hepatitis to neuroinflammatory hepatitis, fibrosis cirrhosis, and hepatocellular carcinoma (Rasowl N, et al., 2010).

Documented evidence has been reported that reactive oxygen species (ROS), superoxide, and hychoxyl radicals are known to play an important role in liver disease pathology and progression (Rasowl, 2010). Antioxidants appear to act against disease processes by elevating the levels of endogenous antioxidant enzymes, such as superoxide dismutase (SoD), catalase (CAT), and reduced glutathione (GSH). Clinical trials have shown that the leaf extract of Vernoniaamygdalina exerts hepatoprotective effects   in acute viral hepatitis (Vitagline, 2004).

1.2.9        Description of Vernonia amygdalina

It is a common medium sized shrub abundant in the South Eastern part of Nigeria. It contains bitter substances in every part of the plant and is widely used in Nigeria for both therapeutic and nutritional purposes (Ezugulu and Nze, 1998), where it serves as ingredients of a delicacy called “bitter leaf soup”. The leaf decoction of the plant is traditionally employed as an anti-diabetic remedy.

Aqueous leaf extracts of Vernonia amygdalina caused prompt and reduction of blood glucose in normal, fasted STZ induced rats.

1.2.10    Aims and Objectives

The aim and objectives of this research work is to determine the anti-diabetic properties and effect of bitter leaf soup with garri on blood glucose and growth performances of STZ induced TYPE 1 diabetes rats.