EVALUATION OF NUTRITIVE PROFILE OF A VEGETABLE, PIPER METHYSTICUM, LOCALLY KNOWN AS AWA USING ATOMIC ABSORPTION SPECTROSCOPY

CHAPTER ONE

INTRODUCTION

1.1       Herbs

An herb is a plant that is valued for flavor, scent, medicinal or other qualities other than its food value (John, 2000). They are used in cooking, as medicines, and for spiritual purposes. Herbs have a variety of uses including culinary and medicinal usage. General usage differs between culinary herbs and medicinal herbs (John, 2000).  Herbs are “generally recognized as safe” by the Food & Drug Administration (FDA), at least at concentrations commonly found in foods (Kaefer et al, 2008). Medicinal plants continue to provide valuable therapeutic agents, both in modern medicine and in traditional system (Reaven, 1983). The leaves, roots, flowers, seeds, root bark, inner bark (cambium), berries and sometimes the pericarp or other portions of the plant might be considered in medicinal or spiritual use (John, 2000). In the medicinal uses, herbs (plants) contain phytochemicals that have effects on the body (John, 2000).

Until the 20th century, (Sanusi et al, 2008) most medicinal remedies all over the world were obtained from plants. For example, purple forglove was found to be helpful in dropsy, the opium poppy for pain, cough, and diarrhea, and the cinchona bark for fever. With the emergence of chemical and pharmacological methods in the 20th century, it became possible to identify the active ingredients in the plants and study them. Furthermore, once the chemistry was understood, it was possible to synthesize related molecules with more desirable properties. According to (Sodimu et al, 2008), today, the two most effective and widely accepted drugs for the treatment of malaria today emerged through herbal traditional medicine viz: Quinine from the bark of the Peruvian cinchona tree and artemisinin from the Chinese antipyretic Artemisia annua L. Hence, throughout history, the medicinal benefits of herbs are quoted (John, 2000). There may be some effects when consumed in the small levels that typify culinary "spicing", and some herbs are toxic in larger quantities. For instance, some types of herbal extract, such as the extract of St. John's-wort (Hypericum perforatum) or of awa (Piper methysticum) can be used for medical purposes to relieve depression and stress (John, 2000). However, (Milner et al, 2008), large amounts of these herbs may lead to toxic overload that may involve complications, some of a serious nature, and should be used with caution. One herb-like substance, called Shilajit, may actually help a lower blood glucose level which is especially important for those suffering from diabetes.

In comparative terms, (Metuh, 1987) the western idea of medicine and the traditional African conception differ in scope. In the traditional sense, it refers to a wholistic view of well being, while in the western sense, it is strictly limited to bodily therapeutic purposes. Nze in his own comparative analysis of medicine underscores the peculiarity difference, which defines the traditional wholistic perception of medicine (Metuh, 1987).

According to (John, 2000), modern pharmaceuticals had their origins in crude herbal medicines, and to this day, many drugs are still extracted as fractionate/isolate compounds from raw herbs and then purified to meet pharmaceutical standards. Some herbs are used not only for culinary and medicinal purposes, but also for psychoactive and/or recreational purposes; one such herb is cannabis (John, 2000).

However, many herbs and their bioactive components are being investigated for potential disease prevention and treatment at concentrations which may exceed those commonly used in food preparation herbs (Milner et al, 2008). It is therefore imperative to identify any potential safety concerns associated with the use of various dosages which range from doses commonly used for culinary purposes to those used for medicinal purposes since there are often unclear boundaries between the various uses of herbs (Milner et al, 2008).

Other uses of herbs other than medicinal uses are:

Sacred uses:

According to “Chinese herbal medicine” Herbs are used in many religions for example, myrrh (Commiphora myrrha) and   frankincense (Boswellia spp) in Christianity, the Nine Herbs Charm in Anglo-Saxon paganism, the Neem tree (Azadirachta indica) by the Tamils, holy basil or tulsi (Ocimum tenuiflorum) in Hinduism, and many Rastafarians consider cannabis (Cannabis sp) to be a holy plant (John, 2000). Siberian Shamans also used herbs for spiritual purposes. Plants may be used to induce spiritual experiences, such as vision quests in some Native American cultures (John, 2000). The Cherokee Native Americans use sage and cedar for spiritual cleansing and smudging.

Uses as pest control:

Herbs are also known amongst gardeners to be useful for pest control. Mint, spearmint, peppermint, and pennyroyal are a few such herbs. These herbs when planted around a house's foundation can help keep unwanted critters away such as flies, mice, ants, fleas, moth and tick amongst others. They are not known to be harmful or dangerous to children or pets, or any of the house's fixtures (John, 2000).

1.2       Objectives of study

Piper methysticum being a plant used for its medical and social purposes (Johnston et al, 2008), may have been of great benefits in human health due to its biochemical, pharmacological, and medical properties. This study, therefore, was undertaken to evaluate the trace – element composition of the leaf extract.