2.2 Traditional Medicine
2.2.2 Herbal Medicine
Herbal medicine, also known as phyto-therapeutic agents or phyto-medicines, are standardised herbal preparations which are made up of plants for combating health problems (Calixto, 2000:
180). World Health Organization (2005:1) defined herbal medicine as “plant-derived material or preparation with therapeutic or other human benefits, which contains either raw or processed ingredients from one or more plants”. In most cases, it is also made up of inorganic materials as well as animal origin. According to WHO (2002b), herbal medicine encompasses finished
herbal products, herbs, herbal preparations and herbal materials which contain active ingredients of plants. The World Health Organization (1998) also categorized herbal medicines into three groups which include:
Processed plant materials: These are plant materials treated according to traditional procedures to improve safety and efficacy, and to facilitate their clinical use, or to make medicinal preparations.
Medicinal herbal products: These are finished labelled pharmaceutical products in dosage form that contain one or more powdered plant materials, extracts, and purified extracts or partially purified active substances isolated from plant materials.
Raw plant materials: These are also fresh or dry plant materials which are marketed whole or simply cut into pieces.
Medicines considered to be combinations of plant materials and chemically active ingredients, including chemically defined or isolated constituents of plants, are not recognized as herbal medicines (ibid).
Long before orthodox medicines came to widespread use across the world, herbal medicines played a vital role in human health care. Herbal medicines have been and continue to be used alongside allopathic drugs around the world in some capacity. Plant medicine is usually used to offer the first-line of treatment and primary health care for people both residing in remote and poorer communities where it is the only available and affordable health service (WHO, 2003). World Health Organization (1998) suggested that the interest in herbal remedies as well as their utilization have been increasing even in areas where modern medicine is available.
The use of plants for health and medicinal purposes dates back to the beginning of human history and much of modern medicines were originated from plant sources (Pal & Shukla, 2003). The World Health Organization (1998) also highlighted that medicinal plants are important ingredients for manufacturing of pharmaceutical medicines. It has been reported that not less than one quarter of conventional drugs are obtained from medicinal plants (WHO, 2011; Sharma, Kumar, Mishra, & Gupta, 2010). Furthermore, it is estimated that between 35
000 and 70 000 plant species have, at least, at one point in time, been utilized in some capacity for medical reasons (WHO, 1998).
Calixto (2000) is of the view that herbal medicines have a wide range of therapeutic use but may not have strong pharmacological action to offer emergency treatment. The author further suggested that herbal medicine exhibits some characteristics which distinguish it from modern medicine. These include: active substances are rarely known; setting up of quality measures;
stability and standardization are possible but difficult, problem of getting quality raw materials;
suitability for chronic treatments and wide range of therapeutic uses; practical use in folk medicine; and less expensive and a well-controlled double-blind clinical and toxicological studies to prove their efficacy and safety are rare. Zhang (1998) noted that herbal medicines differ from conventional drugs in that herbal medicines are derived from raw plant materials in which a part of the plant may contain several natural constituents and are often used over a longer period of time.
Herbal medicine is one of the traditional medical practices that primarily use medicinal plant preparations for therapy. Many herbal medicines used in traditional health care today have long historical record of usage for thousands of years and are embedded in the belief systems of a particular ethnic group, before the spread of modern medicines. It has been established that prolonged clinical experiences built over several years provide a strong evidence of safety and the effectiveness of herbal medicines (WHO, 1998).
However, the renewed interest and increase in consumption of herbal medicines have raised concerns about the quality, efficacy and safety of these medicinal products. Although, herbal medicines are perceived as natural, they are not always safe. The consumption of some plant medicines has caused adverse drug events (WHO, 2005), while others contain chemicals like carcinogenicity and hyper-toxicity that have long-term negative side effects (WHO, 1998).
This phenomenon can be attributed to the wrong choice of plant species; over-dosage;
contamination by poisonous substances, and adulteration of herbal products with other, undisclosed medicines by patients; and the misapplication of herbal medicines by either health practitioners or patients, or with other medicines (WHO, 2005).
It has been recommended that, though, herbal medicines have been tested for safety and efficacy by way of continued uneventful historical procedures, scientific studies could offer
extra proof to meet regulatory requirements (WHO, 1998). Calixto (2000) also suggested that plant medicines that are used for treatment, prevention, diagnosis and mitigation of diseases must be registered and regulated as pharmaceutical product with proven safety and efficacy.
Herbal medicine has been widely acknowledged as a critical resource that can be harnessed to become either another source of health care or complement the national health care system set up at all levels of health care delivery. As a result of the strategic importance of herbal medicines in health care delivery worldwide, WHO has been supporting member countries by designing strategies and policies to be followed to bridge the gap created by modern medicine.