We are IntechOpen, the world’s leading publisher of Open Access books Built by scientists, for scientists 6,200 169,000 185M Open access books available International authors and editors Downloads Our authors are among the 154 TOP 1% 12.2% Countries delivered to most cited scientists Contributors from top 500 universities Selection of our books indexed in the Book Citation Index in Web of Science™ Core Collection (BKCI) Interested in publishing with us? Contact [email protected] Numbers displayed above are based on latest data collected. For more information visit www.intechopen.com 17 Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis , an Interdisciplinary Study Kirley M. Canuto, Edilberto R. Silveira, Antonio Marcos E. Bezerra, Luzia Kalyne A. M. Leal and Glauce Socorro B. Viana Empresa Brasileira de Pesquisa Agropecuária, Universidade Federal do Ceará, Brazil 1. Introduction Plants are an important source of biologically active substances, therefore they have been used for medicinal purposes, since ancient times. Plant materials are used as home remedies, in over-the-counter drug products, dietary supplements and as raw material for obtention of phytochemicals. The use of medicinal plants is usually based on traditional knowledge, from which their therapeutic properties are oftenly ratified in pharmacological studies. Nowadays, a considerable amount of prescribed drug is still originated from botanical sources and they are associated with several pharmacological activities, such as morphine (I) (analgesic), scopolamine (II) atropine (III) (anticholinergics), galantamine (IV) (Alzheimer's disease), quinine (V) (antimalarial), paclitaxel (VI), vincristine (VII) and vinblastine (VIII) (anticancer drugs), as well as with digitalis glycosides (IX) (heart failure) (Fig. 1). The versatility of biological actions can be attributed to the huge amount and wide variety of secondary metabolites in plant organisms, belonging to several chemical classes as alkaloids, coumarins, flavonoids, tannins, terpenoids, xanthones, etc. The large consumption of herbal drugs, in spite of the efficiency of synthetic drugs, is due to the belief that natural products are not toxic and/or have fewer side effects, the preference/need for alternative therapies, and their associated lower costs. In developing countries, herbal medicine is the main form of health care. In Brazil, where there is one of greatest biodiversity of plants in the world, pharmaceutical assistance programs, such as “Living Pharmacies”, have a prominent role in spreading the rational use of medicinal plants mainly for poor people, under recognition by World Health Organization (WHO). Furthermore, herbal medicines also represent a significant pharmaceutical market share in some industrialized countries like Germany. On the flip side, herbal drugs are discredited by most of the health related professionals, owing to a lack of scientific research supporting its efficacy and safety. In general, physicians feel insecure in prescribing herbal medicines, as most of them do not undergo through clinical trials, phytochemical analysis, and their active principles not being www.intechopen.com 354 Phytochemicals – A Global Perspective of Their Role in Nutrition and Health determined. Therefore, herbal medicines do not have a defined dosage, information on the chemical composition and warnings about possible risks. Additionally, the poor quality control of herbal drugs, which are subject to adulteration and intrinsic factors related to used raw material, do produce variables and inconsistent effects. Furthermore, most herbal drugs are produced from wild source, limiting the production at industrial level and putting the species used under threat of extinction. Due to these aforesaid limitations, disadvantages and drawbacks of herbal medicine, we would like to present an updated review of chemical, pharmacological and agronomic studies of Amburana cearensis as a well succeeded example of a scientific research on wild plants and a model of a sustainable economic utilization of medicinal plants. HO H N H H N H O O H O O H N O O HO I II III HO HO H H CO 3 O N O H N O HO NH H H O O O H3CO OH HO V IV HO H HO N VI O O O O OH O N N H O O H VII. R= CHO O VIIII. R= CH3 N H3CO NO H OH OH H O R O H3CO OCH3 H HO H OH HO OH O O HO H 3 IX Fig. 1. Chemical structures of plant-derived drugs 2. Herbal drugs and phytopharmaceuticals According to the WHO definition, herbal drugs are preparations containing plant parts (leaves, roots, seeds, stem bark, etc.) or whole plant materials in the crude or processed form, as active ingredients, besides some excipients. Herbal preparations can be found www.intechopen.com Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis, an Interdisciplinary Study 355 under different forms: oral tablets, capsules, gel caps, syrup, extracts and infusions. In general, combinations with chemically defined active substances or isolated constituents, are not considered to be herbal medicines. (Calixto, 2000). The information about the therapeutical properties and usage of medicinal plants are commonly based on the empirical knowledge of ancient people, which was passed over several generations and originated the traditional medicine systems, utilized all over the world (Traditional Chinese Medicine, Ayurvedic system, Western and African Herbalisms). An estimated quantity of 50 000 plant species are used for medicinal purposes, from which the stand out species of the following families, such as Apocynaceae, Araliaceae, Apiaceae, Asclepiadaceae, Canellaceae, Clusiaceae and Menispermaceae (Schippmann et al., 2002). From the total of 252 drugs in the WHO's essential medicine list, 11% are exclusively derived from plant origins (Sahoo et al., 2010) Herbal drugs are consumed by three-quarters of the world’s population in the treatment of mainly chronic diseases, particularly headache, rheumatological disorders and asthma (Inamdar et al., 2010). In the developing countries, the population relies basically on medicinal plants for primary health care, since modern medicine is expensive and not easily accessible. However, the consumption of herbal drugs is also large in developed countries. Phytotherapy is popular in many countries of Western Europe (Germany, France, Italy, etc.), since people believe that either herbal drugs are devoid of side-effects or seek a healthier life style. Americans usually buy herbal products as a dietary supplement in the United States, aiming at preventing aging and diseases like cancer, as well as diabetes (Calixto, 2000). Herbal drugs have some features which distinguish themselves considerably from synthetic drugs. Herbal medicines are always formed from a complex mixture of chemical compounds (eg. Scutellaria baicalensis has over 2000 components), and they may be constituted by many plants, therefore herbal drugs show an ample therapeutic usage. It is quite common to find a medicinal plant with several therapeutic properties (Sahoo et al., 2010; Calixto, 2000). The combination of either many plants, containing diverse bioactive substances or a pool of structural analogs, can produce a synergistic action that results in a stronger effect, therefore, permitting a reduction of dosage, which implies in lower risks of intoxication and undesirable side effects. As some diseases (e.g. AIDS or various types of cancer) possess a multi-causal etiology and a complex pathophysiology, a medical treatment may be more effective through well-chosen drug combinations than a single drug. Ginkgolides A and B, isolated from Ginkgo biloba, duly demonstrated a greater effect on the thrombocyte aggregation inhibition, when used as a mixture as opposed to what would be expected from the sum of the two compounds separately (Wagner, 2011). On the other hand, plant-based products do not possess a well-defined chemical composition, due partially to chemical complexity stated above. Hence, the active principles of herbal drugs are frequently unknown, in addition to their standardization and quality control, being hardly achieved (Calixto, 2000) owing to mainly chemical variability in raw material. Secondary metabolites are the bioactive components from herbal drugs and their contents are strongly influenced by several factors: genetic (genotypes, chemotypes), physiologic (circadian rhythm, phenology, age), environmental (climate, sunlight exposure, water availability, soil, agronomic conditions) and manufacturing conditions (harvesting, storage and processing) (Tab. 1), (Sahoo et al., 2010; Gobbo-Beto & Lopes, 2007). www.intechopen.com 356 Phytochemicals – A Global Perspective of Their Role in Nutrition and Health Evaluated Plant Compound (s) Result Effect Seasonality Hypericum perforatum Hypericin 300x content larger in summer than winter. (Southwell & Bourke, 2001) Harvesting Ocimum gratissimum Eugenol 98 % at 17h, but it is 11 % at time midday (Silva et al. 1999) Age Papaver somniferum Morphine 6x content larger on the 75th day after germination than on the 50th day (Williams & Ellis, 1989) Phenology Gentiana lutea Mangiferin/ Before flowering- [Mangiferin] ; isoorientin during flowering-  [Isoorientin] (Menković et al., 2000) Temperature Nicotiana tabacum Scopolamine [Scopolamine] 4x larger after freezing (Koeppe et al, 1970) Water H. perforatum Hyperforin/ Under water stress:  2x availability Hypericin [Hyperforin] and  [Hypericin] (Zobayed et al, 2007) Table 1. Effects on the production of secondary metabolites Furthermore, most herbal drugs are utilized and commercialized without having a proven efficacy and safety through well-controlled double-blind clinical and toxicological trials, as pharmaceuticals are usually tested prior to being marketed. The safety and efficacy of herbal drugs are supported by their long historical use. Nevertheless, it is known that various herbal drugs fail, after testing in clinical trials and there are numerous reports on intoxication cases associated with their consumption. The WHO database has over sixteen thousand suspected case reports, related to intoxication by herbal drugs. The most frequent adverse reactions are hypertension, hepatitis, convulsions, thrombocytopenia and allergic reactions. Cardiovascular problems with the use of ephedra, hepatotoxicity caused by the consumption of kava-kava and comfrey, as well as licorice-related water retention, are some side effects claimed by the pharmacovigilance authorities. In addition to intrinsic factors mentioned above, the herbal drugs efficacy and safety, may also be seriously affected due to botanical misidentification or intentional usage of fake plants, contamination with pesticide residue, toxic heavy metals, pathogens and mycotoxins, as well as adulterants added to increase potency (synthetic substances) or the weight of herbal products in order to reduce costs (Sahoo et al., 2010; Calixto, 2000). For the purpose of overcoming or mitigating the aforesaid inconvenient issues, WHO has developed a series of technical guidelines and documents in relation to the safety and the quality assurance of medicinal plants and herbal drugs preparations, such as “Quality Control Methods for Medicinal Plant Materials” (a collection of recommended test procedures for assessing the identity, purity and content of medicinal plant materials), “Guidelines on good agricultural and collection practices for medicinal plants”, as well as “WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues”. In turn, pharmaceutical laboratories have been investing in the enhancement of the quality for herbal products, aiming at the approval by governmental regulatory agencies, as a strategy to offer more reliable products, therefore conquering the confidence of health care professionals and consumers (Sahoo et al., 2010). www.intechopen.com Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis, an Interdisciplinary Study 357 The interest in herbal drugs is continuously growing and they account for a significant share in the pharmaceutical market. The global herbal pharmaceutical industry (including drugs from herbal precursors and registered herbal medicines) invoices approximately US$ 50 billion/year (2008). In 2006, the best selling herbal products were: Ginseng (>U$ 1 billion global sales), Ginkgo (U$ 1 billion), Noni (U$ 1 billion), Saw Palmetto (U$ 600 millions) Echinacea (U$ 500 millions), Valerian (U$ 450 millions), and Green Tea (U $ 450 millions) (Gruenwald, 2008- Entrepreneur). The United States, China, Japan, Germany, South Korea and India, are the largest market. Medicinal plants have also been utilized as source of phytochemicals for the pharmaceutical, cosmetic and agrochemical industries. The most successful examples are paclitaxel (an anticancer drug from Taxus baccata), artemisinin (an antimalarial agent from Artemisia annua), vincristine/vinblastine (anticancer substances from Catharanthus roseus). The Pharmaceutical industry is interested in phytochemicals, however, the availability of quantities of pure chemical substances is normally a limiting factor, since the market demand for phytochemicals, usually reaches a scale from hundreds to thousands of kilograms per annum. (McChesney, 2007) 3. Medicinal plants threatened by extinction The increasing demand for medicinal plants has endangered several species, since the main source of herbal drugs is the wild plant and the amount required from plant materials invariably exceeds the supply available from its natural source. Although the Convention on Biological Diversity (CBD), held in 1992, has established as goals, the conservation of biological diversity, the sustainable use of its components as well as the fair and equitable sharing of the benefits from the usage of genetic resources, it is still estimated that slightly more than 4000 medicinal plant species are under threat of extinction. The Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES), being the principal tool for monitoring or restricting the international trade of species threatened by over-exploitation, has published a biannual list of medicinal species like: Taxus wallichiana, Panax quinquefolius, Dioscorea deltoidea, Hydrastis canadensis, Prunus africana , Rauvolfia serpentina and Pterocarpus santalinus (Schippmann et al., 2002). The overexploitation of a certain wild medicinal plant and consequent depletion of its raw material affect inevitably the economic feasibility of any phytopharmaceutical business in medium or long-term, since the production cost tends to be higher and the product supply become discontinuous. Furthermore, the extractivism provokes loss of genetic diversity, becoming the remaining plant population more vulnerable to diseases/pests and diminishing the variability of genotypes with features of interest such as yielding, bioactive substance content and resistance to biotic and abiotic factors (Rao et al., 2004). Hence, agencies concerned with conservation policies are recommending that wild species be brought into cultivation systems in order to assure the economic and environmental sustainability of herbal medicines trade (Schippmann et al., 2002). Ginkgo biloba and Hypericum perforatum are some of the top- selling medicinal plants, however they are not endangered, because their plant materials have been obtained by cultivation for a long time (Canter et al., 2005). 4. Cultivation of medicinal plants The cultivation of medicinal plants is advocated as a means for meeting current and future demands for large quantities of herbal drugs, but also as a way to relieve the pressure of www.intechopen.com 358 Phytochemicals – A Global Perspective of Their Role in Nutrition and Health harvesting on wild populations (Schippmann et al., 2002). In China, one of the largest markets of herbal medicine, 380,000 ha of lands are utilized for farming of medicinal plants. Medicinal plants are also cultivated for supplying phytochemicals. Bristol-Myers Squibb developed a system of production based upon isolation of a precursor of Taxol from the leaves or needles of cultivated Taxus baccata or T. wallichiana that provide the hundreds of kilograms of Taxol required per year for the treatment of cancer patients. (McChesney, 2007) From the perspective of the market, domestication and cultivation provide a number of advantages over wild harvest for production of herbal drugs: (1) reliable botanical identification; (2) uniform and high quality raw material. As wild plants are dependent on many factors that cannot be controlled and the irregularity of supply is a common feature, the cultivation assures a steady source of raw material; (3) price and volume between farmer and pharmaceutical companies can be more easily negotiable, since the production forecast is more precise; (4) genetic breeding and biotechnology tools can lead to the development of plant materials with agronomically and commercially desirable features, permitting to optimize yield and to meet regulations as well as consumer preferences, respectively; (5) cultivated material can be easily certified as “organic product” (Schippmann et al., 2002; Canter et al, 2005). Cultivated plants account for 60-90 % in terms of amount of plant material employed by Herbal medicines companies, but the number of wild species still is larger. Although the cultivation is apparently more advantageous than wild harvesting, only 130-140 species are cultivated in Europe, while just 20 out of 400 medicinal plants marketed in India are grown in field. Likewise, amongst 1000 plants more commonly used with medicinal purposes in China, only 100-250 species are sourced from cultivation. There are some reasons that can explain this low utilization of cultivated plants: (1) Belief of that wild specimens are more potent than cultivated plants. Chinese believe that the physical appearance of wild roots to the human body symbolizes vitality and this feature is crucial for the potency of the ginseng roots, nevertheless cultivated roots do not exhibit this characteristic shape. Furthermore, some scientific studies support partly this hypothesis saying that secondary metabolites, the main responsible for therapeutic properties of herbal medicines, are biosynthesized by plants under particular conditions of stress and competition in their natural environments. Hence, perhaps the secondary metabolites would not be so expressed in monoculture conditions, therefore the active ingredient levels can be much lower in cultivated plant. (2) Domestication of wild plant is not always technically possible. Many species are difficult to cultivate because of certain biological features or ecological requirements (slow growth rate, special soil requirements, low germination rates, susceptibility to pests, etc.). (3) Economical feasibility. Domestication requires a long time of agronomical studies and high financial investment for the plantation. Generally, production costs through cultivation are higher than wild harvesting, thus few species can be marketed at a high sufficient price to make cultivation profitable, for instance Garcinia afzelii, Panax quinquefolius, Saussurea costus and Warburgia salutaris. Hence, many endangered medicinal plants only will bring into cultivation, if exists governmental incentive (Schippmann et al., 2002). www.intechopen.com Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis, an Interdisciplinary Study 359 However, the cultivation of medicinal plant in agroforestry system can be a good alternative for more viable and environmentally sustainable farming. In China, ginseng (Panax ginseng) and other medicinal plants are grown in pine (Pinus spp.), Paulownia tomentosa and spruce (Picea spp.) forests; besides some medicinal herbs are often planted with bamboo (Bambusa spp.). In New Zealand, American ginseng showed better growth under Pinus radiate. The shade offered by forest species seems to favor the growth of medicinal plants. Likewise, quinine yields of Cinchona ledgeriana increase when it is protected by shade of other species, such as Crotalaria anagyroides and Tephrosia candida. In India, some medicinal plants that have also been successfully intercropped with fuel wood trees (e.g., Acacia auriculiformis and Eucalyptus tereticornis) and coconut. Intercropping gives some income to farmers during the period when the main trees have not started production. (Rao et al., 2004). Application of traditional and biotechnological plant-breeding techniques can become the cultivation of medicinal plants a trade more attractive (eg. increasing the yielding) as well as it can improve features of the plant that affect the efficacy and safety of a herbal drug (eg. levels of bioactive compounds or presence of potentially toxic substances). Mentha spp (mints) have been engineered to modify essential oil production and to enhance the resistance of the plant to fungal infection and abiotic stresses. Genetic engineering allowed the enhancement of scopolamine and artemisinin in Atropa belladonna and Artemisia annua, respectively. (Canter et al., 2005) 5. Amburana cearensis A. cearensis (Fabaceae) is a native tree from “Caatinga” (a kind of vegetation found in the Brazilian semi-arid region), where it is popularly known as “cumaru” or “imburana-de- cheiro” (Fig. 2). Because of these said popular names, A. cearensis is usually misidentified as Dipteryx odorata (Fabaceae) and Commiphora leptophloeos (Burseraceae). A. cearensis occurs widely in South America (from Peru to Argentina), along with another species of this taxon, Amburana acreana, which is found chiefly in the southwestern region of the Amazon Forest. A. cearensis can reach 15 m of height and 50 cm of diameter, but it is characterized by white flowers and dark pods containing only one seed each, besides its stem bark possessing reddish stains and a vanilla-like aroma of coumarin (1). At the early stage of development (seedlings), A. cearensis displays a hypertrophied and subterraneous tube-like structure, called xylopodium, which acts as a storage of water and nutrients, therefore it is considered an adaptive strategy for arid habitats (Lima, 1989; Cunha & Ferreira, 2003). Given the various applications, A. cearensis has a great commercial importance in Northeastern region of Brazil. Its wood is used in the carpentry for the manufacturing of furniture, doors and crates, owing to its recognized durability, whereas the seeds are used as flavoring and insect repellents. The wood powder from it can be added to alcoholic beverage barrels for accelerating the aging process of sugar cane distilled spirits (cachaça) (Aquino et al, 2005). The seeds and stem bark are traditionally utilized for treating respiratory diseases, such as influenza, asthma and bronchitis due to anti-inflammatory, analgesic and bronchodilator properties. As far as folk medicine is concerned, A. cearensis is consumed as a homemade medication called "lambedô (a sugary drink), however in an industrial scale, the syrup is a pharmaceutical form, which is produced by the government and private laboratories (Fig. 3). www.intechopen.com 360 Phytochemicals – A Global Perspective of Their Role in Nutrition and Health Fig. 2. A wild specimen of Amburana cearensis in its natural habitat. The medicinal use of A. cearensis is based on scientific studies, which demonstrated that this plant possesses therapeutic properties that justify its recommendation for the treatment of respiratory illnesses. Preclinical tests demonstrated bronchodilator, analgesic and anti- inflammatory activities for the hydro-alcohol extract from the stem bark of the A. cearensis, which also showed to be free of toxicity in therapeutic doses. The chemical composition of the stem bark and seeds from it, consists basically of coumarin, flavonoids, phenol acids and phenol glucosides. Some of them were tested individually and showed pharmacological activities similar to the extract, hence they were considered the active principles of the A. cearensis. However, the intense commercial use of A. cearensis has led to the threat of extinction for this specie. In order to ensure the conservation and the economic utilization of A. cearensis, we proposed the replacement of its stem bark of a wild adult plant for a young specimen, cultivated under controlled agronomic parameters. In an interdisciplinary study, ethanol extracts of cultivated plants were compared to the extracts of this wild plant through preclinical trials and phytochemical analysis. www.intechopen.com Phytochemistry, Pharmacology and Agronomy of Medicinal Plants: Amburana cearensis, an Interdisciplinary Study 361 Fig. 3. Syrups made from the trunk bark of Amburana cearensis. 5.1 Agronomical study of A. cearensis The agronomical study of A. cearensis was carried out with seedlings obtained by seed germination. Each plot consisted of six regularly spaced rows of 20 cm, whose sowing density was 50 seeds/row. The seedlings were transplanted to four garden beds (1.2m×10 m), fertilized prior to an organic fertilizer (2.8 kg m-2), containing each of them 20 young plants. Fig. 4. Seedlings of A. cearensis harvested in 8th month of growth Eight harvestings were performed monthly, starting on the 2nd month until the 9th month after the sowing. The plants harvested were evaluated with the following parameters: fresh plant weight, plant height, xylopodium diameter, root size, ethanol extract yield from the aerial part and xylopodium (Fig. 4). The fresh biomass production of A. cearensis seedlings increased almost eight-fold, during the 2nd through 9th month after the sowing. With reference to ethanol extract yield, there was a tendency of decrease for the extract weigh/xylopodium weight ratio over a period of time, while an oscillatory behavior was observed for yield of the ethanol extract from its aerial part, achieving a plateau on the 3rd and 7th month (Leal et al. 2011) www.intechopen.com