Chapter 1
African Natural Plant Products: A Foreword to the Science and Challenges Mark Blumenthal American Botanical Council Founder and Executive Director Austin, Texas 78714-4345
Africa has been and continues to be a significant source of medicinal and aromatic plants to the world’s food, drug, herb and dietary supplement market, and in the past decade numerous African plant materials have established a strong international market presence. This book provides an excellent opportunity to delve into the current and future contributions that African plants can and will continue to make both internal to Africa and on the global stage.
This book expertly covers various medicinal plants of African origin and the some of the latest basic and clinical research supporting their ongoing and potential uses in self-care and healthcare. This work also examines various issues and trends in medicinal plants from their uses in Traditional Medicine and ethnobotany, to our modern understanding of the plants’ chemistry and pharmacognosy, natural products chemistry and applications of medicinal plants, quality control, and models of benefit sharing. People around the world enjoy Africa’s culinary contributions. These include the peanut (Arachis hypogaea, Fabaceae), yam (Dioscorea spp., Dioscoreaceae), watermelon (Citrullus lanatus, Cucurbitaceae), okra (Abelmoschus esculentus, Malvaceae) and many other foods and flavors. In North America and in many other parts of the world there is little recognition of the many contributions that Africa has made to modern culture, i.e., perhaps beyond the domain of ethnobotanists and pharmacognosists. From the medicinal and beverage perspective any checklist of economically important medicinal plants from sub-Saharan Africa would have to include at © 2009 American Chemical Society
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4 least two key plants that have become household words around in America and the entire world: The caffeine-containing extract of the seeds of the West African evergreen kola tree (Cola nitida and C. acuminata; Sterculiaceae) was employed by Atlanta pharmacist John Stith Pemberton as a significant ingredient in a refreshing fountain syrup used as a stimulant beverage in the late 1800s. That beverage, Coca-Cola®, became one of the most recognized brands in the world, and spawned an entire class of non-alcoholic beverages or “soft” drinks, i.e., colas. For those that prefer another caffeine containing beverage, the world must again honor sub-Sahara Africa for bringing to us coffee. While the origins of coffee may be shrouded in mystery, it is clear that Coffea arabica L. and its ancestors originate in East Africa. Unlike many cultures in Asia, particularly India and China, where written records document the use of medicinal plants at least 3500 years ago, the ethnobotany of sub-Saharan Africa is a discipline that has been relatively difficult to adequately chronicle and describe, as most of the traditional African cultures are based on oral tradition, much of which had not begun to be documented until the arrival of Arabic, and later European, botanists during in the past millennium (although Graeco-Roman medical botany also included African plants). Previous publications have documented much of the traditional ethnobotany of Africa, a continent with a wide range of plant species and cultures. Favorites in my library include the ambitious volume, African Ethnobotany-Poisons and Drugs: Chemistry, Pharmacology, Toxicology by Hans Dietter Neuwinger (1996) which covers much of the pharmacology of some 240 poisonous and medicinal plants of sub-Saharan Africa; Neuwingers’ other book, African Traditional Medicine: a Dictionary of Plant Use and Applications (2000); Edward Ayensu’s Medicinal Plants of West Africa (1978) and Ben-Erik Van Wyk and Nigel Gericke’s focus on the ethnobotany of South Africa, People's Plants: a Guide to Useful Plants of Southern Africa (2000); and Ben-Erik van Wyk, B. Van Oudtschoorn and C.F. .Hansmann’s Medicinal Plants of Southern Africa (1997). Africa has been and continues to be a significant source of medicinal plants to the world’s food, drug, and herb and dietary supplement market, and in the past decade numerous African plant materials have established a strong market presence. These include the increasingly popular beverage rooibos (Aspalathus linearis, Fabaceae), the prostate remedy pygeum (aka African prune, Prunus africana syn. Pygeum africanum, Rosaceae), the recently popular appetite suppressant dietary supplement hoodia (Hoodia gordonii, Asclepiadaceae), the increasingly popular cosmetic ingredient shea butter (Vitellaria paradoxa, Sapotaceae), and the classic aphrodisiac herb used in psychiatry, yohimbe (Pausinystalia johimbe, Rubiaceae). Further, recent clinical trials document the benefits of extracts of the roots of the South African Pelargonium (umckalaoba, Pelargonium sidoides, Geraniaceae) for use in bronchitis, tonsillitis, and other upper respiratory tract infections. Detailed reviews of rooibos and another on umckalaoba are presented in this work. The cover story of the American Botanical Council’s journal HerbalGram (number 79) reviews the nutritional and other uses of the oil from the kernels of the “Tree of Life”, the marula tree (Sclerocarya birrea, Andacardiaceae). A
5 previous HerbalGram article reviewed the potential promise of a Ghanaian medicinal plant in the constant war against malaria; basic science and several clinical trials demonstrate the potential anti-malarial benefit of Cryptolepis sanguinolenta (Asclepiadaceae) roots in an oral infusion and again you will find an updated review of this promising medicinal plant, Cryptolepis, or golden root in this work as well. Why more attention is not being paid to this potential lifesaving plant is a mystery. Increased use of African medicinal plants on the continent and in international trade has stimulated new efforts to monitor the quality of these botanical materials with the formation of the African Herbal Pharmacopoeia project. The first monographs to establish identity and criteria for quality control were introduced in 2009. This effort will no doubt lead to a greater sense of confidence in many of the leading botanical raw materials of African origin in the medicinal plant trade. The editors of this volume have spent an extensive period of time working with African medicinal and aromatic plant scientists and producers through their integral affiliation for over a decade with ASNAPP (Agribusiness in Sustainable African Natural Plant Products, www.asnapp.org), an international effort dedicated to stimulating and improving production of raw materials and valueadded agricultural products for African farmers, including medicinal and aromatic plants using world-class science and market-first driven models while ensuring the environmental sustainability of those resources and the economic development of Africa. As noted in numerous market reports in North America and elsewhere, there is a bright future for the appropriate development, marketing, and use of medicinal plants and related products in foods, dietary supplements, “natural health products” (the regulatory term in Canada), over-the-counter and prescription drugs, and cosmetics. This book provides an excellent opportunity to delve into the current and future contributions that African plants can and will continue to make to this expanded worldwide market.
