EFFECT OF METHANOL EXTRACT OF Piper umbellatum LEAVES ON CONCEPTIVE INDICES IN RATS

EFFECT OF METHANOL EXTRACT OF Piper umbellatum  LEAVES ON CONCEPTIVE INDICES IN RATS

CHAPTER ONE

INTRODUCTION

Herbal medicine or phytotherapy or traditional medicine refers to practices and knowledge that existed before the arrival of modern conventional medicine, this form was use to promote maintain and restore health and well-being. Herbal medicine has a central role to play in the 21st century. Partnerships between communities of traditional medicine, public health and health researchers have great potentials, particular in areas of prevention and management of disease conditions like malaria, tuberculosis, HIV/AIDs, infertility and others (World Health Organisation, 2002).

The universal role of Herbal medicine in the treatment of diseases in exemplified by their employment in all the major systems of medicine irrespective of the underlying philosophical promise of how and when such medicinal plants were first used. A complete understanding of medicinal plant involves a number of disciplines including commerce, botany, horticulture, chemistry, enzymology genetics, quality control and pharmacology. (Trease and Evans, 2000).

 

  • HERBAL MEDICINE

Herbal medicine, or phytotherapy is the science of using Herbal remedies to treat the sick. It covers everything from medicinal plants with powerful action such as Digitalis, morphine, Belladonna others include cannabis, marigold and theobroma. Those with very mild or gentle action include chamomile and mint (Rudolf, 1988). The term phytotherapy has come be internationally accepted for herbal medicine, being clear and unmistakable.

This was introduced by the French physician Henri Lederi (1870 – 1955). He had published numerous essays on the use of medicinal plants in the management of diseases (Rudolf, 1988).

A medicinal plant is any plant which, in one or more of it’s organs, contains substance that can be used for therapeutic purposes or which are precursors for the synthesis of useful drugs (Soforwora, 1993).

The WHO also made a description that makes it possible to distinguish between medicinal plants whose therapeutic properties and constituents have been established scientifically and plants that are regarded as medicinal but which have not yet been subjected to a thorough scientific study.

Herbal, medicine has come a long way since the days of the ancient herbalism. The study of  the use of medicinal plants is now a scientific subject, a field of medicine in the same way as chemotherapy, hydrotherapy, electrotherapy and others. Knowledge of medicinal plants and their uses has been recorded from antiquity by Imhotep. The priest-physician of ancient Eypt who devised the step pyramid of Sakkara, by Galen, personal physician to the Roman emperor Marcus Aurclius, and later by Paracelsus, the Abbess Hildegard of Bingen and the authors of great Herbals of medieval times, right to the present day (Rudolf, 1988).

According to medicinal history, Hippocrates was the first Greek to regard medicine as a science, some of the medicinal plants described by Hippocrates include opium, mint, sage, rosemary and verbena. Theophrastus of Athens was another famous Greek, who was born in 370B.C at Eresus in Lesbos and produced a number of monographs including the famous Historia plantanum which became the standard botanical textbook in his time and for years after his death. The great work of Diocorides (A.D.60). De Materia medica was regarded as the standard reference work in Europe during the medieval period because it contained the description of some 600 medicinal plants. The use of medicinal plants among the Australian aborigines probably dates back many centuries but was first observed at the end of the eighteenth century, when the settlers found the aborigines using medicinal herbs together with ritual rites (Sofowora, 1993).

Herbal medicines which is the act of using medicinal plants to cure diseases should be regarded as finished labeled medicinal products that contains active ingredients in aerial or underground parts of plants or other plant material or combination thereof whether in the crude state or as plant preparation (Sofowora, 1993).

  • THE USE OF PLANTS IN TRADITIONAL MEDICINE

The use of plants in traditional medicine has been described by the World Health Organisation as one of the surest means to achieve total health care coverage of the worlds population. Thus interest in traditional knowledge is more widely recognized in development policies and scientific literature because remedies made from plants play an important role in the health of millions of people (Cunningham, 1993).

Of current interest all parts of medicinal plant continue to receive extensive phytochemical and pharmacological investigation as to their uses and for their therapeutic values (Trease and Evans, 2000). Medicaments intended for internal and external application involve the use of vegetable organ of plants such as leaves, barks seeds, roots, latex and resin. For example, the tree known as Neem (Azadirachta indica), the seed oil is confirmed to have therapeutic value as an anti-inflammatory and antibacterial agent. More attention has been focused on it’s toxicity and infertility properties. As an anti-infertility agent. It appears to have potential both in inducing male infertility and as a vaginal and oral contraceptive, where it prevent ovum implantation. The leaf extract has anti malarial and anti ulcer activities.

Piper plants have also been used in treatment of asthma, rheumatic arthritis and rhumatalgia. Piper betle leaf appears to possess tumour inhibiting properties (Trease and Evans, 2000). Ocimum gratissimum leaf and the herb are popular treatments for diarrhea and has antimicrobial activity. Various skin diseases due to infection with bacterial or fungal origin are treated successfully with herbal remedies, these remedies possess strong anti microbial activity against growth of staphylococcus aureus  and Aspergillus niger  are combretum micranthum, Dracaena manii (Sofowora, 1993).

 

1.3   PLANTS AS SOURCE OF NEW DRUGS

        Medicinal plants are of economic importance as potential sources of new drugs. In addition they are used locally as remedies against diseases in developing world. Through the ages, nature has provided human with resources of the essentials of life, including food, medicines and raw materials for the maintenance of clothing and shelter. In particular, higher  plants have been the sources of medicinal plants since the earlier time and today they continue to play a dominant role in the primary health care of about 80% of the World population (Farnsworth et al., 1985).

During the past 60 years, New drugs development have revolutionzed the practice of medicine, converting many once Fetal diseases into almost routine therapeutic exercises. One cause of this medical advance have been a fundamental improvement in the means of developing and testing New drugs from plant source (Katzung, 2002).

The pharmaceutical industry has come to consider medicinal plants as a source for identification of bioactive agents that can be used in the preparation of synthetic medicine (Cunningham, 1993).

Current estimates of the number of species of flowering plants range between 200,000 and 250,000 in some families and 10,500 genera. Natural products and medicinal agents are mostly derived from spermatophyte the dominant seed bearing plants of the land which is divided in evenly between the phyla Gymnospermae and the Angiospermae and is further divided into monocotyledons and Dicotyledon both of these provides many useful drugs (Trease and Evans 2000).

The plant kingdom still holds many species of plant containing substances of medicinal value which are yet to be discovered. The wealth of uninvestigated material available is illustrated by the fact that it was reported that natural product research elicited 3,500 new chemical structures of which more than 2,600 were from higher plants (Trease and Evans, 1996).

The two factors which determine the commercial geographical source of a drug are the suitability of the plant to a particular environment and the economic factors associated with the production of a drug in a particular area. Many plants grow equally well in numerous localities having similar climates and as economic conditions changed in one area so the collection or cultivation of a drug plant may be more in accordance (Trease and Evans, 2000).

 

1.4   PHARMACOLOGICAL ACTIVITY OF SOME SELECTED PLANTS

        The study of medicinal plants and their  products and one which emphasizes its pharmaceutical use, can be based on it’s pharmacological action. Some major pharmacological grouping involve drugs which act on the Nervous systems, heart and blood vessels, lungs, gastrointestinal tract, kidneys, liver, reproductive organs, skin and mucous membranes, other categories include hormones, vitamins and chemotherapeutic drugs used for the treatment of infections and malignant diseases (Trease and Evans, 2000).

Holmes (1923), reported the presence of toxic principle in Euphorbia hirta used in asthma and respiratory tract inflammations, which appears to be acting directly on the cardiac and respiratory centres and gives good result in chronic spasmodic asthma and bronchitis.

The physiologic action of the glycoside of Pergularia daemia which acts with an equal intensity on the superior and inferior parts of the uterus to bring about contraction leading to delivery can also be known for it’s abortificient and antifertility activity in rats.   The natural plants such as cryptolepia sanguinolenta  possesses more pharmacological activities such for urinary tract infection treatment, for it’s hypothermic effect during malaria fever, and reduction of hypotensive effects of adrenaline as well as renal vasoconstructive effects are due to cryptolepine the principle constituent (Sofowora, 1993).

Most of the natural plants acting on the urinary tract also act on the reproductive organs. For example preparations of ergot were traditionally used in childbirth and then largely replaced by the isolated alkaloid ergotamine. Administered as it’s salt has a direct stimulant action on the uterine muscle and reduces the incidence of post partum haemorrhage. The use of Diruetics which have effect on tubular re-absorption of sodium ions. Black haw is a uterine tonic and sedative used for the prevention of miscarriage and for dysmenorrhoea after childbirth (Trease and Evans, 2000).

1.5   PIPERACEAE

        Piperarceae belongs to the piperales family which consist of four genera and about 2,000 species. The plants are tropical, mostly climbing shrubs or liaries with swollen nodes and freshly spikes of flowers. The leaves contain oil cells. The one celled ovary has a single basal ovule and develops into a berry. The seeds contain endosperm and abundant perisperm. The four genera are piper (about 2000 species), Trianaeopiper (18 species), O Honia (70 species) and pothomorphe (10 species) (Trease and Evans, 2000; Dyer et al., 2003).

The piperaceae contains phenolic esters and ethers; pyrrolidine alkaloids; volatile oils and lignans. In South pacific islands an aqueous extract of the roots of piper methysticum (kava-kava) is consumed as a ritual stimulant, large doses cause intoxication. In herbal medicine, the root is used as a diuretic, stimulant and tonic. The active principles are pyrone derivatives (kava lactones) a pipendine alkaloids and piper methysticine (Trease and Evans, 2000).

The phytochemistry of the genus piper is rich in  terms of numbers of compounds discovered but given the diversity of this genus and the intraspecific diversify of secondary metabolites in those specific that have been examined, piper chemistry has not been adequately investigated. The natural products chemistry that has been elucidated is well documented and has been the subject of extensive review (Dyer et al., 2003).

Most piper chemistry has been conducted to find potential pharmaceuticals or cytotoxic: antifungal, anti-tumour, fragnant or otherwise useful to humans. For example safrol occurs in high concentrations in several species of piper, particularly piper hispidinerum. This propenyl phenol and it’s derivatives have been used successful in powerful insecticides as well as in fragrances waxes, polishes, soaps and detergents (Rocha and Ming, 1999).

 

  • Piper Umbellatum
    • Plant Taxonomy and Distribution

Piper umbellatum Willd C. DC; a rapidly growing plant of the piperaceae family, with other name piper subpellatum  Wind,Piper auritum. The common names include cow-foot leaf (Sierra Leonel), Lemba (Malaysia), Tombo, Bumbu, Sakmasakan (Indonesia), Nweweb (Ibibio).

The plant piper umbellatum originates form Mexico and South America, and has been introduced and widely naturalized throughout the old world topics, including South East Asia. This is a perennial scrambling shrub or woody herb that reaches 1 – 2.5m tall. It occurs always in damp locations in evergreen forest undergrowth, swamp forest, on river banks, old rubber plantations, from 150-2100m attitude. The specimen is usually collected at the early stage of flowering (Burkhill, 1985).

 

  • Plant Phytochemical Studies

In the phytochemical studies of piper umbellatum,  three (3) pure compounds have been isolated which are identified as Isoasarone, 2 – (4’ – methoxyphenyl) -3-methyl-5-propenylbenzofuran and 2,3-dihydro-2(4-hydrophenyl)-3-methyl-5-propenylbenzofuran. The chemical structures of these compounds were elucidated by spectral methods. (Fasihuddin, et al., 2002).

Previous phytochemical studies of this genus have led to the isolation of a host of interesting chemical constituents which include lignans, amides, alkaloids and flavanoids. Furthermore some of these compounds have been reported to exhibit potentially beneficial insecticidal properties against a variety of medically important insect, vectors and pests (Duke, 1985).

  • Medicinal Uses of Piper umbellatum

Piper umbellatum, in the West Tropical Africa has a general use in Agric horticulture as food (example as sauce, condiments, spices, flavouring agents) In religion and socially as in Uran local government area of Akwa Ibom State, Nigeria, three leaves of this plant must accompany the ram during the traditional presentation of this animal to the parents whose first daughter is being married (Effiong, 2002 pers.com.).

The leaves of the plant are used for the treatment of haemorrhoids, arthritis, rheumatism, ear treatments, for heart and kidney treatments and as a diuretics and laxative. The leaves can also be used in the treatment of pulmonany disease, veneral disease and stomach problems such as diarrhea and dysentery. The root extract of the plant is found useful in the treatment of cancers, tumours, as antiemetics and as abortificient, the leave extract is also useful in the treatment of menstrual cycle, paralysis, epilepsy convulsion, pregnancy, spasm and small pox (Burkhill, 1985).

The leaf extract of piper umbellatum, mixed with ndom (clay) in the sap of the roots of umbrella tree (Uno) Musanga cecropiodes  is given to pregnant women to treat internal heat (Inyang, 2003).

1.6.4        Previous Work on the Plant

        Acute Toxicity of Piper Umbellatum

Ekpo, (2005) on toxicity testing found that the median Lethal dose (LD50) of the plant was 1920.00+ 170mg/kg. she also showed that the methanolic extract of piper umbellatum at high doses (800-1200mg/kg) exhibited remarkable histological changes in liver, kidney and brain.

 

  • Anti-Conceptive and Estrogenic Effect of Piper Umbellatum

Udofia, (2006) obtained from her research that the leave extract of piper umbellatum protected the mice from conception for 1-3 gestational period, and also causes an increase in uterine wet weight and vaginal opening, concluding that the plant has an anti-conceptive and estrogenic effect.

1.7   AIMS AND OBJECTIVES

The plant piper umbellatum has been found to be useful in the treatment of variety of ailments, of which are haemorrhoids, arthritis and as anti-microbial agent (Akpaetok, 2002). It has also been found useful in treatment of menstrual cycle, fertility and for it’s abortificient effect (Burkhill, 1985).

Inspite this local uses there was no scientific documented records of its effects on Estrus cycle, ovulation and sexual behaviour. Therefore this work is aimed at establishing if this plant possesses any anti-conceptive and through what mechanism of action does its mediate the actions.

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