**1. Herbal medicine**

Herbal medicine (HM) is the fulcrum of complementary and alternative medicine, which in recent times is increasingly gaining widespread popularity all over the world and gradually streaming toward integration into the mainstream healthcare systems [1]. The use of HM cuts across gender, social and racial classes in both developing and developed countries of the world [2–7]. Due to the increasing popularity of HM, stakes in the world markets (local and international) are also rapidly increasing and the annual sale is rapidly approaching US \$62 billion [8]. An important driver in this upsurge in patronage and use includes low cost, the wide acceptance due to its status of being a natural product with the acclaim of low toxicity, efficacy in certain challenging diseases, flexibility in its accessibility, preparation and use.

HM includes preparations of biologically active natural products that consist largely of herbs or herbal materials, some recipes may contain materials such as fungal and bee products, as well as minerals (kaolin, bentonite), ash, shells, insects and animal parts, and are used for the maintenance of health and management of various diseases. HMs can elicit numerous benefits just as some can cause adverse effects. The pharmacologic and most of the toxic effects that are elicited by HMs have been linked to the activities of the secondary metabolites. In many instances, HMs have been appropriately used, misused and sometimes misunderstood. The benefits of HMs as a means of healthcare depends largely on the correct and adequate knowledge, and experiences while misuse as well as misunderstanding have been tracked to the knowledge gap on herbal medicines especially as it relates to their benefits and potential drawbacks by the primary healthcare professionals: doctors, pharmacists, nurses and the public. The attraction to herbal medicine will continue to increase across the globe for various reasons, hence the urgent need for appropriate and enough information on HM especially that which highlights on important topics such as benefits, efficacy, safety, toxicity, research and development, formulation, regulation, analytical techniques, quality control, economic

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

importance, and so on [9]. This book harnesses important information on various aspects of HM, thus, serving as a compendium to enlighten scientists, healthcare professionals and lay users appropriately.

so on. Despite the wide acceptance, benefits and sometimes the misconceptions: there is a compelling need for a decisive control of HMs to ensure that enough and correct information on herbal materials and herbal products are always available to especially healthcare providers and the general public particularly on subjects such as identification, quality, safety and

Introductory Chapter: Introduction to Herbal Medicine http://dx.doi.org/10.5772/intechopen.78661 3

In contrast to the pharmaceutical drugs which often consist primarily of single chemical entity (pure compounds), HMs are typically made up of numerous compounds usually in the crude, unpurified state. Many finished herbal products are made from folk recipes often containing more than one herbal material as the active component [18]. The polynomial constitution of

The constituent polynomial ingredients of many HMs as indicated in many folk recipes are often important for the completeness of the product if desired effects are to be produced. The multicomponent ingredients may boost benefits by enhancing simultaneously certain important pharmacological activities such as absorption, distribution, metabolism and elimination of bioactive components. Also, some constituents may act on more than one receptor or physiological system: probably the reason why many HMs show a wide range of therapeutic

In general, HMs are used for cure, mitigation, treatment and prevention of diseases especially those endemic to the local environment of the herbs [14, 16, 20]. Numerous plants species with folk claims of health benefits/cure abound, however only few have scientific proof or corroboration of efficacy. All the activities of HMs benefits and toxicities are linked to the presence of especially the secondary metabolites. The increasing attention on HM has also stimulated increased research in this area resulting in more information as far as efficacy and folk claims are concerned. Many research efforts have corroborated claims resulting in the commercialization of many herbal products and their nomination as leads in the development of pharmaceutical drugs. Nevertheless, many native HMs still remain untested and their benefits unauthenticated. The limited knowledge on these products has made information on the therapeutic benefits and side effects very limited thus heightening the doubt of their health benefits. It is also common knowledge that many people use HM concurrently with pharmaceutical drugs and for many HM information on the likely outcome of this practice is not available because no study has been carried out. Hence, there is a need for information regarding the likely outcomes of the interactions of sundry HM and the commonly used conventional medicines. This information should be generated during the research and development stage of all commercialized HM and enforced by regulation. Such interactions

most HMs may be the reason for many of their benefits [14, 19].

should also be disclosed in package inserts of products.

efficacy of the HM.

**3. Poly herbal**

benefits.

**4. Efficacy**

With many people now using herbal medicine, safety issues are also becoming an important concern. Indeed, certain HM have been implicated in some important adverse events relating to cardio-, neuro- and nephro-toxicities as well cancers [10–12]. Toxicity due to HMs may occur and their seriousness may vary depending on the type of herb or herbal material, preparation and user: varying from minor to severe and sometimes fatal. Adulterations and concomitant use of herbal medicines with conventional medicines constitute another area of attention, thus, the need for a strict regulation and enlightenment and control.
