Preface   Indian diversity in medicinal flora is unmatched. In India, over 7500 medicinal species are being used by 4635 ethnic communities for human and veterinary health care across the various ecosystems. According to a conservative estimate, the value of medicinal plants related trade in India is to the tune of about Rs. 23,000 million per annum while the world trade is around 120 billion US $. Recent market trends indicate that export market in India is growing faster than domestic market. Though, rich in medicinal wealth, the growing demand for herbal drugs in India, puts a heavy strain on the existing resources. Hence, medicinal plant cultivation has received an impetus in the recent years because of revival of ancient traditions of medicine and due to the promotion of eco-health tourism in the country. Considerable knowledge on the botany and chemistry of medicinal plants are available. As majority of the medicinal species are sourced from the wild, agro technologies are readily available only for a few of the commercially grown species. A systematic compilation of the available information on the promising medicinal species helps in providing specific information on the cultivation and utilization of these crops to farmers, academicians and related user industries. Also, this documented information serves to give an insight to the major research lacunae and formulate appropriate research strategies, in these crops. In this the book on Medicinal Plants, we have compiled information on current status of medicinal plants, their phytochemistry, quality control, good agricultural practices and good manufacturing practices in medicinal plants which are commercially grown and those important in trade. Details on botany, crop improvement, crop protection, crop production, post harvest handling, chemical composition, chemical analyses and uses of commercially grown crops are also included. We do not claim the compilation to be a perfect one but with the available resources and time, maximum effort has been taken to make it informative.

Plants have been a major source of therapeutic agents since time immemorial. The increasing acceptance of traditional herbal systems of medicine, like Ayurveda, within India and outside has resulted in the revival of ancient traditions of medicine. Medicinal plants and their derivatives are thus looked upon not only as a source of affordable healthcare but also as an important commodity item of international trade and commerce. As per World Health Organization estimates, traditional medicines, mostly plant drugs, cater to the health needs of nearly 80% of the world population. The medicinal plant related trade is growing rapidly every year due to the growing recognition of natural products being non-narcotic, with relatively less side effects and being easily available at affordable costs. In India, medicinal plant sector has traditionally occupied an important position in the socio-economic, cultural and spiritual arena of rural and tribal lives. About 8000 flowering plants, 650 lichens, 650 algae, 200 pteridophytes and 150 bryophytes are attributed with medicinal properties. The Indian coded systems encompasses a large number of treaties on recognized systems of medicine viz. Ayurveda, Unani and Siddha. The Ayurvedic system of medicine, which cater to the health needs of a major segment of population currently utilizes as many as 1000 single drugs and over 8000 compound formulations of recognized merit. Other systems of medicine viz. Siddha, Unani and Amchi (Tibetan) systems of medicine together utilize about 1800-1900 medicinal species. Many medicinal plants are the source of clinically useful prescription drugs being used in modern systems of medicine. Also incredible knowledge on phyto medicine is acquired in non-coded form by tribals and rural community, as is clear from evidences related to folklore medicine. Recognizing their importance, medicinal plant sector has been identified as one of the key areas by the Government of India and the Department of Indian System of Medicine and Homeopathy.

Phytochemistry Pytochemistry is concerned with enormous variety of organic substances that are elaborated and accumulated by plants and deals with chemical structures of these substances and biosynthesis, and their natural distribution and biological function. Chemical constituents of plants can be classified in different ways. Based on biosynthetic origin, solubility properties and presence of certain key functional groups, it is classified as phenolic compounds, substances that are readily recognized by their hydrophilic nature and by their common origin from aromatic precursor shikimic acid. Terpenoids share lipid properties and a biosynthetic origin from isopentenyl pyrophosphate (Fig. 1). Organic acids, lipids, alkenes and related hydrocarbons, polyacetylenes and sulphur compounds are derived biosynthetically from acetate. Nitrogen compounds of plants like amino acids, amines, alkaloids, cynogenic glycosides, indoles, purines, pyramidines and cytokinins and chlorophyll are basic substances recognized by their positive responses to either ninhydrin or Dragendorff reagent. Monosaccharides, oligosaccharides, sugar alcohols and cyclitols are water-soluble carbohydrates and their derivatives. Macromolecules of plants such as nucleic acids, proteins and polysaccharides are easily separated from other constituents by their high molecular weights (Harborne, 1984). Some of the therapeutically active compounds are discussed below:

Medicinal plants and their various products are extensively utilized not only in traditional systems of medicine but also in modern medicine throughout the world. In recent times, they have also attracted attention of scientists encompassing various disciplines of medicine and biotechnology for search of new drug molecules and modern drug development. Although several research strategies are followed for drug development only the traditional, empirical and molecular methods/strategies are mostly applied. There is also need of scientific validation for safety, efficacy and rational use of traditional form of medicine along with development of standards for identity, purity and strength (Singh and Bagchi, 2002). Approaches of Drug Developement Following approaches are generally employed to discover and invent new therapeutic agents from plants viz. screening of plant materials, identification of active constituents, pharmacological and clinical evaluation and drug design.

Good Agricultural Practices Guidelines for Good Agricultural Practices of Medicinal and Aromatic Plants is intended to apply to the growing and primary processing of all such plants traded and used in food, feed, pharmaceutical, flavouring and perfume industries. The main aim is to ensure that the raw material meets the demands of the consumer and maintains standards of the highest purity. Important aspects are that, these are produced hygienically, in order to reduce microbial load to a minimum, and are produced with care, so that the negative impacts affecting plant during cultivation, processing and storage can be minimised. The guidelines provide guidance for producers to reduce raw material contamination to the lowest level. This document can be used in bilateral relationship between the supplier and the customer and the products documentation is regarded confidentiall (EUROPAM).

Aloe, known for laxative property is one of the old natural remedies that have emerged as modern miracle drug. Popularly known as ‘nature’s sun screen’ has growing use as skin tonic in cosmetic industry and as a nutraceutical. Aloes are also quite popular among succulent ornamental plants because of their stiff, harsh and rugged habit and are commonly grown in deserts and other dry situations. Genus Aloe is indigenous to African continent and Mediterranean countries such as Greece and Southern Italy, and got naturalized in arid tracts of India. In India, Aloe barbadensis is cultivated on a small scale in Rajastan, Andhra Pradesh and Gujarat (CSIR, 1998). Botany Genus Aloe belonging to Liliaceae comprises 275 species distributed in Africa, Asia and America. Forty-two species belong to Madagascar region, 12-15 to Arabian Peninsula and rest are distributed over tropical South Africa. Aloe barbadensis, A. ferox and A. arborescens are used as herbal drugs. In India, only four species occur and of these, Aloe barbadensis is the most widely naturalized species. These taxa comprise several varieties viz., officinalis, chinensis, littoralis and they cross freely and several intermediary forms occur in semi wild state.

Aconites, the tuberous roots of which contain highly toxic alkaloids, are deadly poisons. In small doses, aconites are beneficial in nasal catarrh, sore throat, gibbous, paralysis and chronic fevers. Aconitum is a genus of perennial, erect or rarely twining herbs distributed over North temperate regions of world. The mountains of Eastern Asia form the primary centre, presenting the greatest diversity of genus. About 28 species are reported from India, mostly confined to alpine and subalpine belts of Himalayas. Of the Aconitum spp. occurring in India, roots of nine species are obtained in Indian market. In fact, aconite sold in Indian market is a mixture of 304 species. Still, A. ferox, known as Indian Aconite, is considered the most important. A. ferox is a perennial herb with tuberous roots. Roots are paired, daughter tuber, ovoid oblong to ellipsoid, with filiform root fibres. Leaves are scattered, orbicular-cordate to reniform, palmately 5 lobed, resembling melon leaves. Petioles are pubescent. Flowers are pale dirty blue, borne in a dense terminal raceme, 10-25 cm long. Follicles are oblong with long, obovoid winged seeds.

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