ABSTRACT
Plants are the original drugs. The Sanskrit word Oushadhi denotes the plant kingdom (ora), and the French word drogue means a dry herb. The earliest mention of medicinal use of plants is found in the Rig Veda (3000 BC), which is one of the oldest repositories of human knowledge (Vohora 1979). There are three kinds of herbal medicines: raw plant materials, processed plant materials, and medicinal herbal products (WHO 1998). The World Health Organization (WHO) denes herbs to include plant material such as leaves, owers, fruit, seeds, stems, wood, bark, roots, rhizomes, or other plant parts, which may be whole, fragmented, or powdered (WHO 2000), and are used for their medicinal or cosmetic properties. Vohora et al. (1973) reviewed common Indian vegetables, which form part of the daily meals of the masses, to show that these edible plants are attributed with many medicinal properties. Many modern drugs originated from plants, and natural products constitute a major source of drug development in the pharmaceutical industry (Harvey 2008). Out of 800,000 plant species on Earth, about 25% have been categorized, and only a small fraction has been pharmacologically evaluated. Despite this fact, the use of herbal medicines and nutraceuticals continues to expand rapidly across the world in different healthcare settings (WHO 2004; Abdin and Abrol 2006). A tremendous increase in the use of herbal products has been observed during the last three decades with not less than 80% of the world population relying on them for primary healthcare. Bandaranayake (2006) attributed this to an increased tendency for self-medication. Ekor (2013) has listed varied factors which are responsible for increased patronage of herbal drugs including dissatisfaction with orthodox pharmaceuticals; the erroneous belief that herbal products are superior to manufactured medicines; greater rapport with traditional healers; patients’ belief that herbal medicines might be effective in certain diseases for which modern medicines have been ineffective, inadequate, and expensive; and improvement in quality and efcacy of herbal drugs following utilization of modern science and technology in their development. Over the past decade, the surge in herbal medicines has been estimated to be 40% of all healthcare services in China. The percentage of the population that has used herbal medicines at least once is Australia (48%), Canada (70%), United States (42%), Belgium (38%), and France (75%) (Ekor 2013). This shows that the usage is not restricted to developing countries in Asia and Africa.
