EXTACTION OF ALKALOID FROM CARICA PAPAYA (LEAF) AND, THE REVIEW OF ITS MEDICINAL PROPERTIES AND POTENTIAL BENEFITS

EXTACTION OF ALKALOID FROM CARICA PAPAYA (LEAF) AND, THE REVIEW OF ITS MEDICINAL PROPERTIES AND POTENTIAL BENEFITS

ABSTRACT

 Carica papaya, a plant widely used in the traditional medicinal system of India has been reported to possess analgesic, heart tonic, anti-inflammation, anti-helminitic and to treat malaria fever, dengue fever, ringworm, high blood pressure, stomachache, skin sores, fungal infections, jaundice, rheumatism, psoriasis, sand also used for removal of cancerous growths, burns and scalds. This project is to extract alkaloid in this plant and highlights some of the medicinal or pharmacological aspects of the papaya plant. Extraction of the phytochemical was done using method, where 50g of 5g each (i.e 10 samples) of the dried pulverized dried papaya leaves were weighed into a 250ml beaker and 200ml of 10% acetic acid in ethanol were added and covered and allowed to stand for 4hrs. This was filtered and the extract was concentrated on a water bath to one-quarter of the original volume. Concentrated ammonium hydroxide was added drop wise to the extract until the precipitate was completed. The whole solution was allowed to settle and alkaloid precipitated. The precipitate was washed with dilute ammonium hydroxide then filtered. The residue is the alkaloid which was dried and weighed, yielding 0.3g(6%), 0.44g(8.8%), 0.49g(9.2%), 0.31g(6.2%), 0.50g(10%), 0.46g(9.2%), 0.45g(9%), 0.40g(8%), 0.45g(9%) and 0.39g(7.8%) of a dark green alkaloid residue for ten (10) samples of 5g each. The findings of this study recommends that Carica papaya plants may serve as an alternative to modern drugs in the treatment of certain diseases and also help to sensitize people on the benefits of Carica papaya plants.

CHAPTER ONE

1.0       INTRODUCTION

1.1       BACKGROUND OF THE STUDY

The plant kingdom has proven to be the most useful in the treatment of diseases and they provide an important source of all the world’s pharmaceuticals. The most important of these bioactive constituents of plants are steroids, terpenoids, carotenoids, flavanoids, alkaloids, tannins and glycosides. Often a time, the bioactive compounds in the plants that intrigue the chemist are the nitrogen containing bases called alkaloids. Alkaloids have complex molecule structures. They are usually bitter in taste and are characterized by powerful physiologic activities. Some alkaloids stimulate the central nervous system, while others cause paralysis. Some alkaloids are derived from relatively simple precursors such as ornithine,lysine, phenylalanine, trytophan, histidine, tyrosine, aspartic acid and anthranilic acid. The alkaloids content in plants is usually within a few percent and is inhomogeneous over the plant tissues and could be classified as true alkaloids, proto alkaloids, and pseudo alkaloids (Rajnikant et al., 2005). Depending on the type of plants, the maximum concentration is observed in the leaves, some in the fruits or seeds, others in the root or bark. (Grinkevich and Safronich, 1983). Furthermore, different tissues of the same plants may contain different alkaloids and these alkaloids are extracted by dissolving the plant in dilute acid. Plants in all facet of life have served a valuable starting material for drug development (Ajibesin, 2011). The phytoconstituents are antibiotic principles of plants yet these compounds were not well established due to the lack of knowledge and techniques.

Carica papaya also known as paw-paw is one of the many medicinal plants of great importance to the health of individuals and communities especially in the developing countries than orthodox medicine, and there is lower incidence of adverse effects after use. These reasons might account for their worldwide attention and use. The papaya plant is a small un-branched tree (about 20-30 ft in height) which is from Caricaceae family; the sole specie in the genus Carica, Said to be a native of the Caribbean and Central America, the Papaya is now grown abundantly throughout tropical America, Hawaii and many other tropical countries. It is an interesting tree, practically, every part of Carica papaya is of economic value and its use ranged from nutritional to medicinal and other benefits. The edible part of papaya which is the fruit is a good source of iron, magnesium, calcium and an excellent source of vitamin A and C (Nakasone and Paul, 1998). In fact the vitamin C content in Carica papaya is much higher than in either tomatoes or oranges (Benson and Poffley, 1998). The Natural compounds isolated from various parts of the plant such as leaves, fruits, stem, roots, seeds have been shown to possess excellent medicinal properties including anticancer, antiviral, anti-inflammatory, antimicrobial, anti-diabetic, antihypertensive, wound healing activity, free radical scavenging activity and increase in thrombocyte count, etc. The unripe fruit of papaya is used as mild laxative and abortifacient agent and leaves are used for treatment of pyrexia, malaria fever, diabetes, gonorrhea, syphilis, inflammation and as a dressing component for wounds.

Other benefit of papaya plant is that, papaya is an economical fruit. Besides providing food, the crop has potential to be exploited to serve as source of revenue generation in the country. The fruit produced can serve not only for domestic trade but can also be actively exported to countries like Singapore and Hong Kong. The objective of this study is to extract alkaloids, a bioactive chemical compound present in Carica papaya leaves. This will help in determining of its medicinal value which may be useful in pharmaceutical industry. Also, the economical values of Carica papaya plant which ranged form nutritional to medicinal and other benefits were investigated in this study.

1.2       ALKALOIDS

Human recognition of alkaloids is as old as civilization, since these substances have been used as drugs in potions, medicines, teas, poultices and poisons for 400years. Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties (McNaught and Wilkinson, 1997). Some synthetic compounds of similar structure are also termed alkaloids. (Robert, 1998) In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and more rarely other elements such as chlorine, bromine, and phosphorus. Most alkaloids contain oxygen in their molecular structure are usually colorless crystals at ambient conditions. Oxygen-free alkaloids, such as nicotine or coniine, are typically volatile, colorless, oily liquids. Some alkaloids are colored, like berberine (yellow) and sanguinarine (orange).  Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction. Natural compounds containing nitrogen in the exocyclic position (mescaline, serotonin, dopamine, etc.) are usually attributed to amines rather than alkaloids. Some authors, however, consider alkaloids a special case of amines (Raj, 2004; Aniszewski and Tadeusz, 2007). Most alkaloids are weak bases, but some, such as theobromine and theophylline, are amphoteric .Many alkaloids dissolve poorly in water but readily dissolve in organic solvents, such as diethyl ether, chloroform or 1, 2-dichloroethane, Caffeine, cocaine ,codeine and nicotine are water soluble (with a solubility of ≥1g/L), whereas others, including morphine  and yohimbine are highly water soluble (0.1– 1 g/L). Alkaloids and acids form salts of various strengths. These salts are usually soluble in water and ethanol and poorly soluble in most organic solvents. Exceptions include scopolamine hydrobromide, which is soluble in organic solvents, and the water-soluble quinine sulfate. Most alkaloids have a bitter taste or are poisonous when ingested. Alkaloid production in plants appeared to have evolved in response to feeding by herbivorous animals; however, some animals have evolved the ability to detoxify alkaloids. Some alkaloids can produce developmental defects in the offspring of animals that consume but cannot detoxify the alkaloids. One example is the alkaloid cyclopamine, produced in the leaves of corn lily. During the 1950s, up to 25% of lambs born by sheep that had grazed on corn lily had serious facial deformations. These ranged from deformed jaws to cyclopia. After decades of research, in the 1980s, the compound responsible for these deformities was identified as the alkaloid 11-deoxyjervine, later renamed to cyclopamine. (Thomas et al, 2004).

1.2.1    ACTIVITY OF ALKALOIDS

Alkaloids have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine ), anticancer (e.g.homoharringtonine), (Kittakoop et al, 2014) cholinomimetic (e.g.galantamine ), (Russo et al, 2013) vasodilatory (e.g. vincamine ),antiarrhythmic (e.g. quinidine), analgesic (e.g.morphine), (Raymond et al, 2010) antibacterial (e.g. chelerythrine ), (Cushnie et al, 2014) and antihyperglycemic activities (e.g. piperine). (Raymond et al, 2010) .Many have found use in traditional or modern medicine , or as starting points for drug discovery .Other alkaloids possess psychotropic (e.g.psilocin ) and stimulant activities (e.g. cocaine,caffeine , nicotine) and have been used in entheogenic rituals or as recreational drugs. Alkaloids can be toxic too (e.g. atropine , tubocurarine). (Robbers et al, 1996) Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly invoke a bitter taste.

1.3       STATEMENT OF THE PROBLEM

Developing countries are face with high level of poverty, high cost of living because of inflation and increasing resistance of diseases such as cancer, malaria, dengue fever and many more to orthodox drugs. With the passage of time, many problems associated become prominent like severe side effects. In recent times, research on medicinal plants has been intensified all over the world.

There is an urgent need to discover new antimicrobial agents for human and veterinary therapeutic uses, as resistance to current drugs increases in severity and extent with frequent use. For instance, many Plasmodium falciparum strains, the parasite responsible for many fatalities from malaria, have become resistant to chloroquine (Robert and Meunier,1998). This phenomenon has also occurred with some important pathogenic bacteria (Setti and Micetich, 1998). As a result, more than two billion people worldwide are at high risk of malarial/bacterial diseases. The identification of new and structurally novel natural products with antimicrobial activity, and hopefully new modes of action, is one of the ways of tackling this problem. By targeting alkaloid-containing medicinal plants, specifically Carica papaya plant, it is hoped that structural novelty with the required bioactivity will be achieved more efficiently. Alkaloids have diverse structures and many show a range of pharmacological activities, there is a need to facilitate the herbal research and its application to solve the problem of health seeking population.

On the other hand synthetic drugs are expensive and a large population cannot afford these drugs. The need for a cheap, renewable, easily available and nutritive source of drug supplements has therefore attracted the investigation of Carica Papaya leaf as an alternative. This study delves to prove the effectiveness of papaya leaf extract as an agent with pharmacological capabilities thereby increasing access to health care services and reduce cost.

1.4       JUSTIFICATION

Medicinal plants play a major role in the health care sector of developing nations for the management of diseases. They have macronutrients and micronutrients, which have curative and preventive role in combating diseases and for the proper functioning of vital organs in the body. The phytochemicals and mineral elements in plants are preserves of good health and boost body immunity.

Phytochemical and bioactivity studies have been done on Carica Papaya revealing the presence of alkaloids, steroids, flavanoids and many more, and they have been attributed to the curative properties of the plants. The mineral elements in this medicinal plant could also contribute to their curative functions. This study therefore sought to determine the medicinal properties and other benefits of the plant.

1.5       AIM AND OBJECTIVES

The aim of this research work is to determine the potential medicinal properties of Carica papaya plant.

Objectives

1. To extract alkaloid, a photochemical present in Carica Papaya leaf, this helps in determining its potentials that may be useful in pharmaceutical industries.

1. To ascertain the quantity of some phytochemicals such as alkaloids in Carica Papaya, this will help in determining the effectiveness of the medicinal plants in treating various diseases and to understand their pharmacological action.

1.6       SIGNIFICANCE OF THE STUDY

The significance or importance of Carica payaya plant cut across its economical values ranged from nutritional to medicinal amongst some potential benefits. It is known that papaya leaves is one of by-products from papaya tree. These by-products are generally disposed in open areas. Rather than that, one potential alternative use for these wastes is extraction of phytochemicals such as alkaloids and others which produce valuable products. Utilization of leaves can create waste to wealth, hence reducing the disposal problem. Furthermore, it has been proved that isolated phytochemicals from papaya leaves can gives benefit to human health. These alkaloids can be used as remedy against various diseases, including cancer, malaria, dengue fever, diabetic heart disease and infectious diseases etc. Thus, this papaya leaves can create waste to health as it is efficacious and chemotherapeutically becoming an alternate health care system to solve the health problems of world in today’s synthetic allopathic era.

Cost wise the Carica papaya is very cheap and this plant is cosmopolitan in distribution meaning it is very much available in most of the parts of the world. The finding will also be used as a baseline study for other researchers working on medicinal plants and used to sensitize people on the role of traditional medicine. The concern about the quantitative estimation of various essential element concentrations is important for determining the effectiveness of the medicinal plants in treating various diseases and to understand their pharmacological action.

1.7       SCOPE AND LIMITATION OF THE STUDY

The conceptual and contextual scope of this research includes examining the medicinal potentials (effectiveness) of Carica Papaya, as well as extracting alkaloids, a phytochemical contained in the leaf of Carica Papaya using a feasible method.

Temporal scope of this research is not time or season bound, it can be carried out in wet or dry season provided the resource is available

This research is limited to the qualitative and quantitative analysis of alkaloids, other phytochemicals and bioactive constituents of Carica Papaya leaf such as saponins, flavanoids, steroids glycosides, and phenols were not extracted and analyzed.