CHAPTER ONE

INTRODUCTION

1.1    BACKGROUND INFORMATION

Plants have been used sinced the medieval times for medicinal purposes for the treatment of all kinds of ailments. Some plants apart from serving as food have also been known to exhibit medicinal properties. Over 400,000 species of tropical flowering plants have medicnal properties. (Akpulu et al, 1994). Also about 25% of the drugs prescribed worldwide and found in mordern pharmacopoeias come from plants, 121 such active compounds being in current use. Of 252 drugs considered as basic and essential by the World Health Organisation (WHO,2001), it has been discovered that a total of about 11% are exclusively of plant origin with a large number being synthetic drugs obtained from natural precursors. Some important drug examples obtained from plants are Digitoxin from plant Digtalis spp used in the treatment of heart failures, Quinine used as antimalarials and Qunidine used as antiarythmic are both obtained from plant Cinchona spp, vincristine and vinblastine gotten fron Catharanthus roseus used as anticanceer agents, Atropine from Atropa belladonna and  morphine and codeine from Papaver somniferum. An estimated 60% of antitumor and anti-infectious drugs already in the market or under clinical trials are of natural origins. (Sofowora, 1993).

According to a research by World Health Organisation in 2001 an estimated 80% of the population of developing countries in Africa and Asia  are known to rely on traditional medicine, mostly plant drugs for their primary health care needs. (WHO, 2001). Due to extraction and devlopment of several drugs and chemotherapeutics from these plants as well as from traditionally used herbal remedies, there has recently been an increasing reliance on the utilization of medicinal plants in the industrialized societies. The medicinal properties of these plants are suspected to be as a result of the antioxidant, antipyretic, antimicrobial effects of secondary metabolitesof phytochemicals in them. (Soetan and Aiyelaagbe, 2009). Due to reasons such as ineffiency of conventional medicine (e.g side effects of ineffective therapy abuse and incorrect use of synthetic drugs resulting in side effects and other problems) lack of access  to conventional pharmacological treatment perhaps due to inaccessibility of health care centres and the ever increasing cost of synthetic drugs, there is a general resurgence of interest in medicinal plants and traditional medicines as a whole by a large percentage of the worlds population. Also folk medicine and ecological awareness suggest that natural products are harmless. Although plant based natural medicines are popularly acclaimed to be safe, scientist advocate for proper toxicological studies (Oyewole et al, 2008), in order to ensure safety in the use of natural medicines. Toxicity is the undesirabe property of any drug or chemical capable of producing injurious or detrimental effects on a living organism. Whether or not these injuries occur depend on the amount of chemical absorbed.(Gossel and Bricker, 1990; Betram,1998). The toxic effect caused by drugs is similar in man and other animals,  hence the use of animal models in toxicological studies. Most toxic effects of drugs occur at a predictable time after administration. However, the target organ of toxicity is not neccesarily the site of accumulation.(Oboh, 2009). This study however does not include doses that can induce toxicity upon administration.

Jatropha tanjorensis belongs to the family Euphorbiaceae. It is a common weed of field crops, bush regrowth, road sides and disturbed places in higher rainfall forest zones of West Africa. It is commonly called Hospital Too Far, Catholic Vegetable(Iwalewa et al 2005). The leaf is commonly consumed in many parts of Southern Nigeria as it does not require any special conditions to grow in the Southern soil. It is popular as a medicinal plant and is commonly used as a natural remedy for diabetes, malaria infection hypertension and some other conditions in this region.(Olayiwola et al, 2004). Also acclaimed as a booster of of blood and immune system; however there is a dearth in th scientific validation of these claims.

Phytochemical screening of Jatropha tanjorensis leaf revealed that it contains bioactive principles such as alkaloids, flavonoids, tannins, cardiac glycosides, anthraquinone and saponins (Ehimwenma and Osogie, 2007).

The liver functions as an essential organ making proteins and blood clotting factors, manufacturing triglycerols and cholesterol, glycogen synthesis and bile production. The effect of Jatropha tanjorensis on the liver function of the exprimental animals is determined by testing for liver enzymes suchs as Alkaline phosphatase (ALP), Alanine amino transferase (ALT), Aspartate amino transferase (AST).  

In this study, I investigate the phytochemical composition of Jatropha tanjorensis leaf and also investigate the effect of ethanol extract of the leaf of this plant on the liver function of male albino whistar rats.  

1.2    STATEMENT OF THE PROBLEM

Jatropha tanjorensis is commonly consumed as vegetable and used as a medicinal plant in many parts of Nigeria and has shown hematological, antimalarial, antimicrobial, hypoglycemic, hypolipidemic and antihypertensive activities.(Abiodun et al, 2013). A plant with so many abilities is bound to have   tremendous positive or negative effects on the body. The importance of these effects on the liver function cannot be over emphasized as the liver is a vital organ of the body. A situation where Jatropha tanjorensis exudes a positive effect on the liver must be studied as carefully as a situation where the effect is negative or toxic.

1.3     AIMS AND OBJECTIVES OF THE STUDY

The aim and objectives of this study is to determine the phytochemical constituent of the ethanolic leaf extract of Jatropha tanjorensis and also determine the effects of these extracts on  the liver function of albino whistar rats.

1.4     JUSTIFICATION

In many developing countries such as Nigeria herbal remedies of Jatropha tanjorensis are  often relied upon to solve problems and cure diseases. There is therefore need to establish the effect and the promising potential of herbal products such as the leaf extract of this plant on the liver function.

1.5    SIGNIFICANCE OF STUDY

The results from this study will add knowledge to existing literature about the effects of ethanol leaf extracts of our plant of interest on the liver function of albino whistar rats. This data will be useful as a guide to those that make use of this plant as food or as a medicinal herb to now appreciate  and be mindful of the effects of the leaf of this plant on liver function. Using this research work, the effective doses of extracts of this plant can be obtained as it pertains to human.

1.6     HYPOTHESIS

H1:        Jatropha tanjorensis leaves contains phytochemical compound and have effect on liver function.

H0:        Jatropha tanjorensis leaves do not contain phytochemical compound and have no effect on liver function.

1.7      SCOPE OF THE STUDY

This study is includes the following.

·   Collection of Jatropha tanjorensis leaves.

·   Ethanol extraction of phytochemicals in the leaves.

·   Phytochemical screening of the ethanol extracts of the leaves.

·   Collection and weighing of the experimental animals.

·   Dosage determination.

·   Preparation of solution of the extracts.

·   Administration of extracts of plant to the experimental rats.

·   Withdrawal of blood by cardiac puncture from anaesthesized experimental rats.

·   Seperation of serum by centrifugation.

·   Analysing the effect of treatment on liver function.

·   Statistical evaluation of results.

Discussion of results.