Biodiversity in Plants Herbal Medicine as Medical Alternative: Review on its Origin, Acceptance and Economic Importance

Reader Impact Factor Score
[Total: 1 Average: 5]

Published on International Journal of Health, Nursing, & Medicine
Publication Date: July 5, 2019

Razaq A. Oke & Muinat A. Adebisi
Research Coordinating Unit, Forestry Research Institute
Tree Improvement Section, Department of Sustainable Forest Management Forestry Research Institute
PMB 5054, Jericho Hills, Ibadan, Oyo State, Nigeria

Journal Full Text PDF: Biodiversity in Plants Herbal Medicine as Medical Alternative: Review on its Origin, Acceptance and Economic Importance.

Abstract
With no evidence of the first use of plant by man to treat or cure ailments, reports has it that it was used as early as five thousand B.C. and since then, its usage and acceptance as grown gradually. This paper then reviewed the history of human contact and usage of plants in curing ailments. It also re-examined the plants herbal medicinal value and as a medical alternative to conventional synthetic drugs. It further highlighted the importance of herbal therapy and its preference to conventional synthetic treatment with evaluation of its economy value. This paper resolved that educating and creating awareness on plants medicinal and economic value alongside good government favourable policies will enhance its benefits to all stakeholders.

Keywords: Plant, Herbal Medicine, Synthetic Drug, Ailment, Value & Acceptability.

1. INTRODUCTION
The environment is the closest neighbour of man and man depends directly and indirectly on the environment for almost everything relating to growth and survival on planet earth. Among the major biotic components of the environment are forests and other vegetation and the wise management of the environment depends on a better understanding of its components (Agbogidi and Ofuoku 2007). Given the dynamic nature of the global ecosystem, environment changes, driven by man-made and natural cause is inevitable. Economic activities and the rate of population growth have increased to a point where the effect of humanity on the environment can no longer be ignored (Aimufia, 2002). In line with the above, reasonable numbers of medicinal plant species are threatened by habitat loss following heightened deforestation (Aliyu, 2006, Agbogidi, 2002; Agbogidi and Ofuoku, 2006). Although there is a great incompatibility between urbanizations/ industrializations and agriculture, and conservation developmental activities should be environmentally friendly to allow for a sustained productivity (Agbogidi and Okonta, 2009).
No one knows where or when plants first began to be used in the treatment of illness and diseases, but the connection between plants and health has existed for thousands of years. An accidental discovery of some new plant food or juice that eased pain or relieved fever might have been the beginning of traditional knowledge, which was passed down for generations and eventually became foundation of medicine (Estelle and Karen, 1999). In the United States of America, herbal remedies are offered as homeopathic remedies. All such remedies are regarded as drugs and are offered for treatment of different illnesses and diseases. This means that if a herbal remedy is included in the United State of Pharmacopoeia, the official Homoeopathic Pharmacopoeia or the National Formulary, it will be recognized officially as a drug, if it does appear in any of these official compilation, it will still remain a drug but not an officially recognized drug (Grewal, 2003).
Just as many Europeans knew of the use of Aloe vera (Alloaceae) to treat burns, many indigenous people in Nigeria also know some common plants that have medicinal value. Herbalist and native doctors in Nigeria value all plants in their garden and do not consider any as weeds (Adekunle and Sam-Wobo 2004, Gbile, 1987). The investigation carried out by Adekunle and Sam-wobo (2004) revealed that Chenopodium ambiosioides, Curscuta australis and Plumbage zeylanica among others have been used effectively for the treatment of Guinea Worm (Dracunculus medinensis) infection in Ogun State, Nigeria. Also, Phyllantus Amarus, Enantia Chloranta, Solenostemon monstachyus, Carica papaya and Paaqualina nigrescens have been found effective in treating malaria fever in the south Western Nigeria (Adebisi, 1999). Medicine used by the majority of the population of most developing countries originated from medicinal plants (WHO/UCN/WWF, 1988). Large segment-estimates are 80% of the population of developing countries depends on traditional plant medicines (World Bank, 2001). Traditional medicine is particularly relevant for the poor, many of whom cannot access and afford the cost of allopathic (conventional) medicines (Leng keek, 2004, Adebisi and Gbagir, 2006).
Plants have been major sources of medicine and plant secondary metabolite has been attributed for most plants’ therapeutic activities (Fabeku, 2006, Neumann and Hirsch, 2000). Phytomedicines have shown great promise in the treatment of intractable infectious diseases (Yesilada, 2005). The local uses of plants and products in health care are even much higher particularly in those areas with little or no access to modern health services (Saed et al, 2004). Traditional medicine practice is an important part of healthcare delivery system in most of the developing world (Sheldon et al, 1997) and is a source of primary health care to 80 % of the world’s population (Alves and Rosa, 2005). Traditional medicine has been reported to be the first medical care known to Nigerians and herbal medicine, an aspect of traditional medicine, is becoming increasingly popular in both developing and developed countries (Omwuliri and Wonang, 2005). Traditional medical knowledge of medicinal plants and their use by indigenous culture are not only useful for conservation of cultural traditions and biodiversity but also for community healthcare and drug development now and in the future (Pei, 2001 and Hanazki et al, 2005).
Global and national markets for medicinal herbs have been growing rapidly and significant economic gains are being realized with global sales of herbal products which totaled an estimated US $60 million in 2000 (W.H.O. 2003). Local markets form an integral part of the life and culture of many people in developing countries. The markets are also important socio-economic institutions. The traders in these markets sell large amounts of medicinal plants to the indigenes and foreigners who seek their help of which most of the plant parts are barks, roots, stems and leaves and are sold in dried form (Adekunle, 2004).

2. DRUG PLANTS HISTORICAL PERSPECTIVE AND ANCIENT SUBMISSION
Drug plants were always of special interest. As early as 5,000 B.C. many drugs were in use in China. Sanskrit writings testify to methods of gathering and preparing drugs in these early times. The Babylonians, ancient Hebrews and Assyrians were all familiar with medicinal plants. From Egypt there are records dating to 1,600 B.C. naming many of the medicinal plants used by physicians of that period, among which myrrh, opium, cannabis, aloes, cassia and hemlock are prominent. The Greeks were familiar with many of the drugs of today, evidenced by the works of Hippocrates, Theophrastus, Aristotle and Pythagoras. The supernatural element continued to remain prominent in their culture. However, only a few individuals were taught this dexterity because of some special power to distinguish harmful from valuable plants (Yesilada 2005). This “rhizotomoi” or root diggers were an important case in ancient Greece. In Rome there was less interest in plants that had healing powers. But by 77 BC Dioscorides wrote in his treatise, “De Materia Medica,” dealing with the nature and properties of all the medicinal substances known at that time. This work was highly esteemed for 15 centuries and to this day is valued in parts of Turkey and North Africa. Pliny and Galen also described the nature of some drug plants (Cristina et al, 2005).
Following the Dark Ages there began a period of the encyclopedists and herbalists. The monasteries of Northern Europe produced large compendiums of information regarding plants, much of which was false. They stressed the medicinal value and folklore of plants. About the same time there appeared a “Doctrine of Signatures.” This superstitious doctrine suggested that all plants possessed some sign, given by the Creator, which indicated the use for which they were intended. A plant with heart-shaped leaves was good for heart ailments; the liverleaf with its 3-lobed leaves was good for liver problems, etc. Many of the common names of plants owe their origin to this superstition. Names such as heartease, dogtooth violet, Solomon’s seal and liverwort are examples. Pharmacology and pharmacognosy owe their beginnings to the earlier beliefs and knowledge about medicinal plants. The interest in medicinal plants was especially pronounced among the early botanists who were often physicians (Yesilada 2005 and Cristina et al, 2005).

3. PLANTS DEPICTION
Plants are living things that are seen growing on the surface of the earth and usually have root, stem, leaves and produce fruits and seeds. Their importance as well as roles in nature cannot be over emphasized. Most plants are edible and contain different amount of vitamins, protein or carbohydrates etc, these helps the body to replace worn out cells or tissues, digest food and combat ailments among other health related problems. Since the dawn of history, man has been faced with the challenges of eliminating ailments completely, which its legacy has not been met yet, therefore different ages have been adopting different measures to checkmate ailments, and nevertheless, from creation to date, plants have always been among the most effective primary measures for this check (Proter 1997). Plants have an inert ability to combat ailment and maintain ones state of good health, since it provides the body with vital nutrients. Plants have been proved scientifically to have the ability to cure ailments by providing some necessary nutrients which may be lacking in the body or by attacking the causative organisms themselves. On the other hand, different plant species perform varied roles (ecological niche) which has been harnessed by the ancient and correspondingly used to combat human pathology. Man has used plants from the earliest times to cure disease and relieve physical suffering. Medicinal value of drug plant is due to the presence of some chemical substances (active ingredients) that produce a definite physiological action in the human body (Mbagwu 2009, Africa Journal Online 2011).
The African continent has a long history with the use of plants for medicinal purposes. In some African countries, up to 90% of the population relies on medicinal plants as a source of drugs (Miller 1990, Hostettmann et al 2000). For instance, 80% of the population in Mali uses traditional medicine as their only type of medicine (Diallo and Paulsen, 2000). In Nigeria, 1985 WHO survey estimated that up to 75% of the population patronizes traditional medicine (Bako 2005). The yearly herbal medicine trade fair in Nigeria and increasing publicity and patronage this attracts, irrespective of the social, educative or religious background of the people, are indicative of acceptance of herbal medical practice (Ukwuomah and Costa, 1997).

3.1 Acceptability of Plants as Cure for Ailments
Plants have been used from ancient times to attempt cures for diseases and to relive physical suffering. Many ancient peoples had acquired some knowledge of medicinal plants. Oftentimes these primitive attempts at medicine were based on superstition and speculation. Diabolically, evil spirits in the body were thought to be the cause of medical problems. They could be driven out of the body through the use of poisonous or disagreeable plant substances that rendered the body a disagreeable habitat. Medicine men or women of a tribe were usually charged with knowledge of such plants. The progress of medicine has often been guided by the earlier observations and beliefs (MINAL, 2012).
The World Health Organization estimates that 80 per cent of people in the developing world rely on traditional medicines derived mainly from plants. In Southeast Asia, for example, traditional healers use some 6,500 different plant species to treat malaria, stomach ulcers, syphilis, and other diseases. Biodiversity is also critical to the ‘formal’ health sector of the developed world. A recent survey showed that of the top 150 prescribed drugs used in the United States, 118 are based on natural sources. Of these, 74 per cent are derived from plants. Microbes and animal species have also contributed a range of medicines, including Penicillin (derived from the fungus Pencillium notatum) and several drugs – including anesthetics– derived from the skin secretions of tree-frog species (Fabekun 2006, PROTA 2008). The medicinal importance of biodiversity is particularly impressive considering that only a tiny fraction of earth’s species have been thoroughly investigated for medicinal properties. The investigative process is continually turning up new pharmaceuticals of great promise. A recent study of cone snails, for example, has identified a painkiller that is up to a thousand times more effective than morphine, but without morphine’s addictive properties (Agbogidi, 2007). There are many plants which are used for preparation of the medicines like Vinca rosea (periwinkle) with two alkaloids like vinblastine and vincristine which are used for curing cancer-Hodgkin’s disease and lymphocytic cancer. Almost all the plants have medicinal importance like tea gives caffeine which stimulates the nervous system, Papaver somniferum (opium) yields cocaine which is an analgesic, Colchicum autumnale yields colchicine which has anticancer property, Cinchona tree bark yields quinine with antimalarial property, the roots of Rauvolfia serpentina yield reserpine used to reduce high blood pressure and so on (Saed El at 2004, Adekunle and Sam 2004)

4. MEDICINAL PLANTS VALUE
Medicinal plants are those plants that are used (parts, extract etc) in treating and preventing specific ailments and diseases that affect human beings. Hence the important role of medicinal plants in health care delivery (services) cannot be over emphasized. That branch of medical science dealing with the drug plants themselves is known as Pharmacognosy. It is concerned with the history, commerce, collection, selection, identification and preservation of crude drugs and raw materials. The action of drugs is Pharmacology. Worldwide there are several thousand plants that have been and are still being used for medical purposes (Africa Journal Online 2011). Many of these are restricted in use by native people who have long resided in any given area. The Pure Food and Drug Act of 1906 in the United States has standardized most of the truly valuable drug plants. Such drugs are referred to as “official.” Details about these plants may be found at the United States Pharmacopoeia, the Homeopathic Pharmacopoeia and the National Formulary, and various other sources in the United States and Europe (MINAL, 2012).
Very few drug plants are cultivated. Most of the drug supply is from wild plants growing in different parts of the world, especially in tropical areas. These drug plants are collected and prepared in a crude way for shipment (Jimoh Et al 2019). They eventually reach the centers of the drug trade and are processed. Sometimes a country has built up a monopoly of some particular drug. For example, Japan used to control the export of camphor, agar and pyrethrum, while the Dutch in Java supplied almost all the Quinine (Chichona) for world trade. From 1920-1930 the importation of crude drugs increased 140 percent. Most of the processing of the crude material was carried out in the United States. Additionally, several drugs are produced in the United States either from wild or cultivated sources. These include ginseng, goldenseal, digitalis, cascara, wormseed and hemp. When there are shortages additional plants grown are henbane, belladonna and stramonium (Sheldom et al 1997, WHO 2002).
A plant’s medicinal value is due to the presence in its tissues of some chemical substance or substances that produce a physiological action on the body. Most important are the alkaloids, compounds of carbon, hydrogen, oxygen and nitrogen. Glucosides, essential oils, fatty oils, resins, mucilages, tannins and gums are all utilized. Some of these are powerful poisons so that the preparation and administering of them should be entirely supervised by physicians (Fabeku 2006).

4.1 REASON FOR SORTING FOR HERBAL MEDICINE
Plants and its elements used in Herbal medicine for treatment contains active ingredients that can cure multiple diseases, which is why many people seeks it as alternative therapy especially in Africa. People with lingering ailments turns to herbal medicine more than those with minor ailments, and this is owing to the fact that conventional treatment or use of synthetic drugs has failed or because herbal medicine is cheaper and can be easily accessed or because herbal therapy cures permanently (WHO 2002). Similarly the demand for herbal therapy has increased not just because they are cheap but also because they have minimal or no side-effect, better cultural acceptability and suitable to human body system (Adebisi and Jimoh, 2019). In a research work carried out in Ogbomoso in Oyo State, south west Nigeria, on six HIV patients, been treated with herbal medicine. The result shows that within 20 days of commencement, they show significant improvement, while all the associated symptoms of the virus disappeared (Oniface et al 2013).

4.2 EXORBITANT COST OF TREATMENT
Given the fact that majority of the world’s population are poor or live an average life, traditional medicine is particularly relevant for the poor, many of whom cannot access and afford the cost of allopathic (conventional) medicines (Leng keek, 2004, Adebisi and Gbagir, 2006). In many hospitals across the globe, there’s perception that cost of modern conventional treatment is high and this is owning to the fact that a lot has gone in to putting the system in place. The point that treatment is expensive is because a lot of money goes into planning and management of the hospital, diagnosis equipment, payment of workers (Doctors, Nurses and other supporting staffs) and drugs are relatively expensive. This has made the decision to opt for alternative medicine in herbal and traditional medicinal treatment easy. It’s a lot cheaper and comes with less stress (Leng keek, 2004, Adebisi and Gbagir, 2006).

4.3 Adverse Side Effecs Of Synthetic Drugs
Synthetic drugs also known as designer drugs are man-made artificial corrective drugs for illnesses and diseases. They are laboratory made with different composition of elements/compounds and most times, the chemicals that made up the drugs have high potency to create another problem in human body in the process of healing or curing a particular disease. This is commonly called side effect or adverse effect. Unlike natural traditional medicine with no or insignificant side effect. No one will prefer to suffer another illness or disease in the process of curing one. In this way, it’s easy to choose herbal medicine. There are common patient’s complaints after using synthetic drugs thus: Sweating, Hitching, Drowsiness, Tiredness, Euphoria and Restlessness etc (Ziva 2016).

4.4 Development of Resistance to Currently Used Drugs for Infectious Diseases Have Led to Increased
Use of synthetic drugs to cure infectious diseases has proven effective in early stages of usage and became inactive along the line, this is what scientists refer to as, drug resistance. Micro-organism drug resistance became widespread in the 20th century. In a case study on an antimalarial conventional drugs, there were observation on molecular genetic of drug resistance that include delay in parasite cleansing of artemisinin inactiveness over time (Sa 2011).

4.5 Population Rise and Inadequate Supply of Drugs
The increasing rate of human population and emergence of various new diseases has brought about competition and an increase in the demand for cure, whereas, the available synthetic drugs seems not sufficient to carter for the timing demands. Also the pharmacologist failure to find cure for some ailments has increased the demand for alternative medicine in herbal treatment. Diseases like HIV and AIDS, Ebola and the likes are yet to find a permanent cure till date while there are some revelation to the effectiveness of plant herbal therapy to curing most of this diseases (Onifade et al 2013).

5. PLANTS HERBAL MEDICINE AND ECONOMIC IMPORTANCE
Over the years, plant has serve as source of income and means of livelihood to human especially those inhabiting within and around forest reserves in developing countries. These Inhabitants recognizes the medicinal value and economic importance of plant and they engage in its buying and selling. Meanwhile, the increase in the demand for the use of plants herbal medicine as an alternative medicine has further necessitated the commercialization of medicinal plants and increases the rate at which vendor troops into the business (Evans 2011). It’s now a global business and has attracted a lot of money so much that it has formed part of import and export items of some countries (Saikat and Raja 2011). Researches revealed that hoarder of medicinal plants in South African alone generates Rs. 66.4 million in revenue and around 9,584,904,000 Rial in Oman (Sher, Al-Yemeni and Sher 2010). Its markets has been formalized so much that there is control price system by the sellers in some quarter. Global value of imported medicinal plant materials has been in the range of US$130 million annually since 2012, of which US$10.5 million was exported by Pakistan alone. While countries like China, Pakistan, Indonesia Afghanistan, Thailand, Iran and Tanzania are leading in medicinal plant exportation, countries like USA, Switzerland, Germany, the Middle East countries and many more are leading in importation of medicinal plants (MINFAL, 2012 and Jimoh et al 2019). To this end, it’s important to know that there’s huge potential for herbal plant to become a big global business, capable of improving foreign exchange and balance of payment apart from enhancing individual or group of people’s livelihood. Nevertheless, there’s more work to do inform of awareness and education of it values (Jimoh et al, 2019).

6. DISCUSSION
Clearly, herbal plants has come to stay and may be the first choice for medical therapy within the shortest possible time. Still there are more work to do to make them attain there deserved position in medical treatment. Meanwhile, in the course of this review, it was observed that herbal plants has a long history and has helped to solve series of ailments, also, the economic value it brings is with great potential and if its properly managed, can bring fortune to the world at large in earning through foreign exchange and in solving health problems. Consequently, if awareness of the potential of medicinal plant is widely spread, demand for it could increase. And careful management of the forests and sustainable utilization and conservation of forest plants is essential to it sustenance, in order to avert extinction of plants species of some endangered or threatened plant species. Furthermore, there is more need for proper documentation of medicinal plants uses which are not properly conveyed by the older generation.