PCG 202 2022-1 Organized Vegetable Drugs PDF

Department of Pharmacognosy and Drug Development Gombe State University, Gombe PCG 202: Organized Vegetable Drugs BARKS, WOODS, ROOTS, RHIZOMES, BULBS AND CORMS IBRAHIM H.M 2021/2022 SESSION 1  CRU...

Department of Pharmacognosy and Drug Development Gombe State University, Gombe PCG 202: Organized Vegetable Drugs BARKS, WOODS, ROOTS, RHIZOMES, BULBS AND CORMS IBRAHIM H.M 2021/2022 SESSION 1  CRUDE DRUGS Crude drugs are derived from any part or parts of the plant and may contain one or more active ingredients. These are products from natural source that are used in raw form Crude drugs are defined as an unrefined substances from natural source intended for use in the diagnosis, treatment or prevention of disease in humans and animals. They may be from  Plants  Animals  Microbes  Marine  Mineral sources 2 Based on Structural Organization 3  BARKS Botanically, the bark refers to the outer dead tissues of stems and roots which occur outside the active cork- cambium. It includes the cork, epidermis and lenticels. Pharmacognostic bark consists of all tissues outside the woody part of the stem or root separated by the main cambium. Therefore, the pharmacognostic bark include:  the secondary phloem,  primary phloem,  cortex  and periderm. 4 Figure I: The Tissue Arrangement Of The Bark 5  Periderm is used to describe the cork-cambium and its products (cork and the secondary cortex) Phellem (cork) Phellogen (cork cambium) Phelloderm (secondary cortex) Products of cork cambium includes;  cork cells on the outer side  and phelloderm (secondary cortex) on the inner side. Therefore, the botanical bark is regarded as the outer bark in pharmacognosy and constitutes the outer part of the pharmacognostical barks’ which contains the medicinally active constituents of the plant, or contains undesirable amount of tannins or colouring matter. 6  ANATOMY OF THE BARK The bark consists of the following layers of tissues from inner surface to the outer; 1. One or two layer of cambial parenchymatous cells. 2. A few layers of secondary phloem tissue composed of; sieve tubes, phloem parenchyma, phloem fibres and sometimes stone cells, and is traversed radially by medullary rays. 3. Two or three layers of primary phloem. 4. A layer or two of pericycle. 5. A layer of endodermis. 7 6. A few layers of primary cortical cells. 7. A few layers of secondary cortex. 8. One or two layers of cork-cambium or phellogen. 9. A few layers of cork cells. 10. One or two layers of dead tissues forming the outer surfaces frequently showing lichens, lenticels, and remains of primary tissues cut off by the cork 8  BARK MORPHOLOGY Barks form the outer covering of plants They exhibit various epidermal characters. The external tissues of older barks often have a rugged and scaly appearance due to the presence of;  Lenticels; breathing pores for gas exchange  Cracks,  Fissures,  Wrinkles,  Furrows,  Scales  Strips  Exfoliations  Rhytidome 9 Figure II: Bark Morphology 10  Barks are removed from the stem or root by peeling them after making suitable longitudinal and transverse incisions through the outer layers. The natural curvature of the barks changes when they are removed from the tree and dried. Depending on the size and thickness of the bark removed, a bark may assume any of the following shapes after drying. 11  BARK SHAPES Flat: Thick barks in long pieces are often dried under pressure. The finished product of some plants does not undergo any shrinkage or curvature and remain flat. Example E.g Quillaia Barks undergo shrinkage upon drying and usually form a curvature on the inner side. According to the extent of this curvature different characteristic shapes are formed. These are described as follows: 12  CURVED When the bark is only slightly concave on the inner side. E.g Wild cherry 13  RECURVED In rare instances, the concavity may occur on the outer side, then the shape is termed recurved. E.g Pomegranate 14  CHANNELLED When the curvature on the inner side is deep enough to form a trough. E.g Cassia 15  QUILL When the curvature on the inner side is so deep that one edge of the bark overlaps the other. E.g Cascara 16  DOUBLE QUILL When each edge is rolled independently into a quill. E.g Frangula 17  COMPOUND QUILL When more than one single-or-double-quilled pieces are packed on inside the other, E.g., Cinnamon. 18  BARK INNER SURFACE Barks usually appears paler than the outer surface and can be; 1. Smooth: due to presence of uniform soft tissue 2. Striated: with fine or coarse parallel longitudinal ridges as a result of transverse shrinkage 3. Corrugated: showing transverse parallel wrinkles of fold due to longitudinal shrinkage 19 Figure III: Bark Inner Surface 20  FRACTURES OF BARKS Dried barks break into pieces when subjected to pressure. The behavior of the barks towards the pressure applied and the appearance of the broken surfaces are referred to as their fracture. Fracture is one of the most useful diagnostic characteristics of the barks. Various types of fractures exhibited by different barks are described as follows: 21  Short: When the bark breaks easily with a quick snap and the fractured surfaces are smooth. Fibrous: When the bark breaks with resistance and the broken surfaces snow fine projecting fibres. Granular: When the bark breaks with less effort and exhibit small rounded prominences. Splintery: An irregular fracture, usually into pieces, with larger and smaller projecting edges and splinters. Brittle: When the bark easily breaks into many pieces when dropped on to a hard surface. 22  Fractures of the barks may be; 1. Complete: breaking clearly across as in the cases of short and brittle type of fractures. 2. Incomplete: breaking only a part way across, as in the cases of fibrous, granular and splintery fractures Depending on the type of constituents present in the bark, the fractured surface may appear; 1. Mealy: when it contains abundant starch 2. Resinous: when large amount of resin is present 3. Waxy: due to the presence of plenty of resins, waxes, gums and mucilages in the bark. 23 BARK OF PHARMACOGNOSTIC IMPORTANCE 24 PLANT TISSUE SYSTEM The plant tissue systems are organized to form three types namely;  Dermal or Epidermal tissue  Ground tissue system  Vascular tissue system 25  Dermal or epidermis: stomata, trichomes and pavement cells. Ground tissues: parenchyma, sclerenchyma and collenchyma.  Parenchyma: living with no cell wall. Found in mesophyll of leaf, cortex, xylem, phloem and pith of the stem and root. Types: prosenchyma, xylem and phloem  Collenchyma: living and irregular cell wall. Found in cortex of stem.  Sclerenchyma: dead Sclereid/stone cells (periderm, cortex, pith, xylem and phloem) Fibres Vascular tissues:  Xylem (tracheids, vessel elements, xylem parenchyma, xylem sclerenchyma and xylem fibres)  Phloem (companion cells, sieve tubes, phloem fibres, intermediary cells and phloem parenchyma). 26  CINCHONA BARK 27 Synonyms: Cinchona Bark, Peruvian Bark, Cinchonae Cortex Botanical source: Cinchona consists of the dried bark of various species, races and hybrids of Cinchona, particularly of Cinchona succirubra Pavon (Red Cinchona) C. calisaya Weddell (Yellow cinchona) C. ledgeriana Moens and C. officinalis Linn. Family: Rubiaceae Geographical source: Cinchona is indigenous to Colombia, Ecuador, Peru and Bolivia and it is cultivated commercially in Java (Indonesia) and India. 28 Macroscopical characters of Cinchona Odour: faint characteristics Taste: bitter and astringent Length: 35 cm in length Diameter: 20 to 25 mm in diameter Thickness: 2 to 5 mm Bark shape: quills or double quills and rarely as channeled pieces. Colours: The outer surface is brownish grey or reddish-brown to dark brown in colour and the inner surface is yellowish-brown or reddish- brown in colour Bark outer morphology: longitudinal ridges, fissures and transverse furrows and cracks and numerous grey to white patches of lichens. Bark inner surface: striated. Wood fracture: short fracture, but somewhat fibrous in the phloem and the fractured surface exhibits a thin cork and a broad fibrous layer. 29 Microscopical characters of Cinchona A transverse section of the bark of C. succirubra shows; Cork cells: polygonal, thin-walled, radially arranged and suberised Phelloderm: thin-walled cells Primary cortex: large, isolated, empty secretion tubes, each surrounded by a single layer of secretory tissue. The collenchymatous tissue present usually contains a brownish substance. The parenchyma is made up of more or less rounded cells, some containing microsphenoidal crystals of calcium oxalate, others minute starch grains. Medullary rays of one to three cells wide traverse the phloem tissue, which contains numerous conspicuous phloem fibres. The fibres are either isolated or arranged in irregular radial rows, spindle-shaped, striated, thick-walled and provided with numerous pits and very narrow lumen. Stone cells are usually absent. 30  Periderm 1. Cork 2. Phellogen 3. Phelloderm Cortex Secondary phloem 4. Sieve tubes 5. Fibres 6. Phloem parenchyma 7. Medullary rays Figure IV: TS of Cinchona Bark 31  Chemical Constituents/ Medicinal Uses of Cinchona Quinoline alkaloids: Quinine, quinidine, cinchonine and cinchonidine. It also contains quinic acid and cinchotannic acid. Medicinal Uses: Cinchona possesses febrifuge (reduce fever) properties and has been used in the treatment of malaria fever 32  Substitutes and Adulterants The barks of Remijia pedunculata and R. purdiena (Rubiaceae) Croton eluteria (Euphorbiaceae) Erythrostemom exostemma (Rubiaceae) Eucalyptus stenostoma (Myrtaceae) 33 CINNAMON 34 Synonyms: Cinnamon Bark, Cinnamomi Cortex, Ceylon Cinnamon Botanical source: Cinnamon consists of the dried inner bark of the shoots of coppiced trees of Cinnamomum zeylanicum Nees Family Lauraceae. Geographical source: Cinnamomum zeylanicum is a small evergreen tree indigenous to Sri Lanka and cultivated in Sri Lanka and South India. 35  Macroscopical Characters of Cinnamon Odour: fragrant and aromatic Taste: warm and sweet Length: 1 meter Diameter: 1-2 cm Thickness: 0.5 mm Bark shape: single or double, closely packed, compound-quilled pieces Colours: pale brown Bark outer morphology: marked with pale, wavy, longitudinal lines of pericyclic fibres, and shows occasional scars of the lateral branches. Bark inner surface: faint longitudinal striations and is some what darker in colour than the outer surface. Wood fracture: brittle and splintery The fractured surfaces show dark brown secondary phloem intercepted by pale medullary rays and surrounded by a ring of buff-coloured sclerenchyma. Cork and cortex are absent. 36 Microscopical Characters of Cinnamon 37  Cork and primary cortical cells are absent, except for occasional patches. The outermost layer consists of a 2-3 celled thick and band of pericyclic lignified sclerenchyma associated with occasional groups of pericyclic fibres. Each intact fibre is strongly thickened with pitted, lignified walls and concentric striations. Phloem parenchyma consists of elongated cell exhibiting numerous circular pits and containing acicular microcrystals of calcium oxalate and starch grains. Isolated or groups of fibres, similar to the pericyclic fibres in structure, occur along with the phloem parenchyma. Empty, elongated secretion cells occur in the phloem tissue. Two cells wide medullary rays traverse the phloem. Powdered Cinnamon contains; numerous thick-walled and pitted phloem fibres, isolated or groups, abundant starch grains and acicular microcrystals of calcium oxalate in parenchymatous cells and few sclerenchymatous cells. 38  Chemical Constituents/ Medicinal Uses of Cinnamon Chemical constituents: 0.5-1.0 % volatile oil, tannins and mucilage. Medicinal uses: as a carminative and flavouring agent. It also possesses astringent and antibiotic properties. 39  Substitutes and Adulterants The dried barks of other species of Cinnamon, particularly C. cassia and C. loureiri are used as substitutes and barks of other related plants 40 CASCARA BARK 41 Synonyms: Cascara Bark, Sacred Bark, Chittem Bark Botanical source: Cascara Sagrada consists of the dried bark of Rhamnus purshiana D.C., collected at least one year before being used. The plant is a shrub or small tree belonging to the family Rhamnaceae. Geographical source: The plant is cultivated in Britain, Columbia, Oregon, California and Kenya 42  Macroscopical Characters of Cascara Odour: characteristic faint Taste: bitter and nauseous Length: 5-20 cm Diameter: 2 cm Thickness: 1-4 mm Bark shape: single quills or channed or flat pieces Colours: pale brown Bark outer morphology: transversely elongated lenticels, occasional patches of silver-grey lichens and mussel-scale insects. Bark inner surface: longitudinal striations and faint transverse corrugations. Wood fracture: short and granular to the outer side but somewhat fibrous to the inside 43 Microscopical Characters of Cascara 44  Chemical Constituents/ Medicinal Uses of Cascara Chemical constituents: 1.5-2 % of emodine and other similar anthraquinone glycosides. It also contains dextrose and an enzyme. Medicinal uses: as a cathartic drug, mainly used for the correction of habitual constipation. 45  Substitutes and Adulterants The dried bark of Rhamnus frangula Linn. is the common substitute. Barks of other species of Rhamnus are used adulterants 46 QUILLAIA 47 Synonyms: Quillaia Bark, Soap Bark, Cortex Quillaiae Botanical source: Quillaia consists of the dried bark of Quillaia saponaria Mol. and other species of Quillaia of the family Rosaceae. Geographical source: It is indigenous to Chile and Peru 48 Macroscopical Characters of Quillaia Odour: almost odourless Taste: acrid (extremely or sharply stinging or bitter) Length: 1 m Diameter: 10-15 cm Thickness: 6 mm Bark shape: flat Colours: brownish outer surface and white or yellowish- white inner surface Bark outer morphology: transversely elongated lenticels, occasional patches of silver-grey lichens and mussel-scale insects. Bark inner surface: smooth Wood fracture: splintery 49 Microscopical Characters of Quillaia The bark contains patches of dead ploem tissues, which consists of red-brown thin-walled cells. The secondary phloem tissues consists of tangential bends of sieve tubes and parenchyma altering with bands of phloem fibres, which are often characteristically knotted and bent. Many phloem parenchyma cells contain single prisms of calcium oxalate. Some cells also contain clusters of microcrystals. Sclereids occur infrequently along with phloem fibres. 50  Chemical Constituents/Medicinal Uses of Quillaia Chemical constituents: Quillaia contains two toxic saponin glycosides. It also contains quillajic acid, quillaia sapotoxin, starch and sucrose. Uses: Quillaia is recommended as a stimulant and expectorant 51 WOODS 52  The wood represents the central harder part of all shrubs and trees inner to the pharmacognostic bark. It is the part of a plant body which lies inner to the cambium ring. The wood consists mainly of the xylem tissues (vessels, tracheids and fibres) and associated parenchymatous cells (i.e. the wood parenchyma). The primary and secondary xylems constitute the wood of a plant. 53  With the continuous formation of secondary xylem tissues by the cambium, the primary or original xylem tissues are gradually pushed towards the center and become compact. As time goes on, as the plant increases in girth, the primary xylem tissue dies due to over congestion as well as accumulation of tannins, oils, gums, resins and formation of plugging tyloses (ballon-like-ingrowths) in their cavities 54  The dead xylem tissues give rise to the hard, durable and densely coloured central wood called the heartwood. The function of the heart-wood is to provide mechanical support to the plant. The outer region consisting of the newly formed secondary xylem tissues, which are living, lighter in colour and comparatively softer in texture, constitute the sapwood. This part of the wood is used by the plant for conduction of water and salt solutions from the root to the leaf. 55 ANATOMY OF WOOD 56 ANATOMY OF WOOD 57  Woods used pharmaceutically are obtained both from the heartwood and sapwood, but the largest come from the heartwood. Examples of such woods include: 1. Quassia wood from Picrasma excelsa, 2. Guaiacum wood from Guaiacum officinale, 3. Red Saunders from Pterocarpus santalinus and 4. Sandalwood from Santalum album. 58  EXTERNAL CHARACTERS OF WOODS External characters of a wood, through the transverse section include the annual rings. They appear as bands crossing the piece of the wood from one radial surface to the other. Each ring represents the total in a year, i.e., the spring wood and the summer wood, the latter being much darker forms a dark line on the outer edge of each annual ring. 59  Medullary rays, which cross the annual rings at right angles as parallel lines, are also visible on the surface. Between the rays small holes or pores, representing the vessels, are evident. There are also small patches or bands of xylem parenchyma, which are lighter in colour than the reminder of the xylem. The remainder of the wood consists of fibres, which give hardness and strength of the wood. 60  The type and arrangement of the fibres in the wood determine the splitting properties or grain type of wood, which may be straight-grained. If the fibres are straight and arranged parallel to each other, the wood will splits very easily. Wood that are hard to spilt are said to possess an interlocked grain with wavy fibres which are arranged crossing each other at an angle of about 30 degrees. 61  HISTOLOGY OF WOODS Histologically, woods are composed of five types of cell elements namely: 1. tracheids, 2. vessels, 3. fibres, 4. wood parenchyma and 5. medullary ray parenchyma. Tracheids form the bulk of the woods of conifers, e.g., Pinus spp, Ephedra spp and Alnus spp. 62  Vessels are characteristic of the Angiospermous woods and are absent from the Coniferous woods Vessels occur in various sizes and with different types of secondary thickenings on their walls in various groups of woods. Wood parenchyma occurs in association with the vessels in most woods. The medullary ray parenchyma transverses the wood tissue forming the medullary rays in a radiating pattern. Fibres constitute the major bulk of the wood and determine the wood texture. 63 PHARMACEUTICAL WOODS OF IMPORTANCE 64  DEAL Synonyms: Red Deal, Yellow Deal, White Deal Botanical source: Red or yellow deal consists of the wood of Pinus sylvestris Linn. and that of Picea excelsa Linn. constitutes the White Deal. Other species of Pinus and Abies also yield similar woods. These plants belong to the Pinaceae. Geographical source: Deal plants are grown in many European countries, North America and Canada. 65  MACROSCOPICAL CHARACTERS OF DEAL Deal wood is straight-grained and splits readily longitudinally with smooth surfaces. It is soft in texture and buff in colour, It has a density of about 0.35 to 0.8. It possesses a resinous odour. Annual rings are well-marked, with pores absent but resin ducts occur in the central and outer part of each annual ring. The medullary rays appear as fine whitish lines. 66  MICROSCOPICAL CHARACTERS OF DEAL The wood consists almost entirely of narrow, long tracheids having pits on the radial walls. The pits are large, circular and bordered. Schizogenous resin ducts are abundant in the middle region of each annual ring. Thin-walled parenchymatous cells occur surrounding the resin ducts. Both uniseriate and multiseriate medullary rays are present, which are composed of elongated rectangular or rhomboid parenchymatous cells. 67 CHEMICAL CONSTITUENTS/ MEDICINAL USES OF DEAL Chemical constituents: 1. Deal contains about 75 % cellulose, 2. 25 % lignin, 3. about 1 % resin (colophony) and 4. a small amount of volatile oil (turpentine). Uses: Deal is used as main source of wood cellulose and for making mechanical wood pulp. 68  QUASSIA Synonyms: Quassia Wood, Quassiae Lignum, Jamaica Quassia Botanical source: Quassia is the stem wood of Picraena excelsa (Sw.) Lindl. (Picrasma excelsa or Aeschrion excelsa), the lofy bitter-wood tree of the family Simarubaceae. It is known in commerce as Jamaica Quassia Geographical source: Quassia wood tree grows in the West Indian Islands and the wood is exported from Jamaica. 69  MACROSCOPICAL CHARACTERS OF QUASSIA The wood occurs in logs, rasprings, chips or shavings of variable sizes, Yellowish-white or bright yellow in colour It has a short fracture and specific gravity of 0.54 -0.56. Numerous medullary rays appear as white radial lines on the fravtured surface. The outer surface exhibits a fragmented wood structure with occasional patches of the bark. The arrangement of the xylem parenchyma in tangential bands gives an appearance resembling annual rings. Chips break readily into smaller fragments. The wood possesses an intensely bitter taste but no odour. 70 QUASSIA 71  MICROSCOPICAL CHARACTERS OF QUASSIA Medullary rays of one of five cells wide and 10-15 cells high occur crossing the fibres at right angles; Individual cells are radially elongated with pitted walls and occasionally contains large single prisms of calcium oxalate and starch grains. Wood fibres are long and tapering with moderately thickened and obliquely pitted walls. Vessels usually occur in groups of two or three arranged parallel to the medullary rays, moderately thick-walled with numerous oval bordered pits. Wood parenchyma consists of axially elongated cells with moderately thick, pitted walls and occurs in concentric bands. 72 CHEMICAL CONSTITUENTS/ MEDICINAL USES OF QUASSIA Chemical constituents: Quassia contains the bitter amaroids quassin, isoquassin and neoquassin. Uses: Quassia is used as bitter tonic and given as enema to expel threadworms. It is also used as an insecticide. 73  SANDALWOOD Synonyms: Yellow Sandalwood, Santali Lignum Botanical source: Sandalwood consists of the heartwood of the stems and roots of Satalum album Linn., an evergreen small tree of the family Santalaceae. Geographical source: The plant is widely distributed in India and is cultivated under Government control in Southern India. 74  MACROSCOPICAL CHARACTERS OF SANDALWOOD Sandalwood occurs in logs of up to 1 metre in length and 10-20 cm in diameter, Yellowish or pale reddish in colour, Hard, heavy and dense, but easily splits longitudinally. It possesses a strong fragrant odour and a slightly bitter taste. 75 SANDALWOOD 76  MICROSCOPICAL CHARACTERS OF SANDALWOOD Alternating lighter and darker zones are visible on the transverse surface; The medullary rays are very fine and close together; Vessels are mostly solitary, only occasionally occur in small radial groups. 77  CHEMICAL CONSTITUENTS/ MEDICINAL USES OF SANDALWOOD Chemical constituents: Sandalwood contains 2-5 % volatile oil, which contains about 90-97 % sesquiterpene alcohols, collectively called santalol. Uses: The wood is used as a source of Sandalwood oil, which is a stimulant and disinfectant of the genitor-urinary tract. It is also used in perfumery. The wood is also used to make boxex, carvings and similar articles. 78  GUAIACUM Synonyms: Guaiacum Wood, Lignum Guaiaci, Lignum Vitae Botanical source: Guaiacum consists of the wood (both heartwood and sapwood) of Guaiacum officinale Linn. and G. sanctum Linn. of the family Zygophyllaceae. Geographical source: Guaiacum officinale is native of West Indian Islands and South America and G. sanctum is native to Florida and Bahamas. They are also found in Cuba and Haiti 79  MACROSCOPICAL CHARACTERS OF GUAIACUM Logs of Guaiacum are very hard, heavy and compact. The central heartwood is dark greenish-brown and the surrounding sapwood is yellowish-brown in colour. The outer surface is either smooth or furrowed. The wood has a density of 1.16 to 1.4 and splits very irregularly. It has slight aromatic odour and an acrid taste. 80 MICROSCOPICAL CHARACTERS OF GUAIACUM There are numerous fine, straight medullary rays in the wood. Vessels occur singly or in groups of two or three. They are very wide and extend from one medullary ray to the next, with lumen often filled with masses of yellowish resin. The xylem fibres which form the bulk of the wood are very thick-walled and wavy longitudinally. Xylem parenchyma is scanty and is scattered irregularly or in small bands. The medullary rays are uniseriate and 3 to 5 cells high. Prisms of calcium oxalate and occasionally starch grains occur in some parenchymatous cells and some cells of the medullary rays. 81  CHEMICAL CONSTITUENTS/ MEDICINAL USES OF GUAIACUM Chemical constituents: The heartwood contains 20- 25 % resin. It also contains guaiacsaponic acid and guaiacsaponin, which are present in larger quantity in the sapwood. Guaiaguttin is also present in Guaiacum. Uses: Guaiacum is used in sore throat for its local stimulant action. The resin is used in chronic gout and rheumatism. The wood has been used with Sarsaparilla as an alternative in syphilis. 82  SUBTERRENEAN/ UNDERGROUND STRUCTURES IN PLANT 83 84 UNDERGROUND STRUCTURES 85  ROOTS The roots consisting drugs are usually the strongly developed primary (tap) roots, although many secondary root system sometimes produce some important drugs. Roots bear no leaves or buds. The only appendage present on the roots is the lateral branch-roots which are similar in construction to the main root. Aconite, Belladonna, Calumba, Dandelion, Ipecacuaha, Jalap, Rauwolfia, Sarsaparilla and Senega are some of the important root drugs 86  RHIZOMES They are thickened stems growing horizontally, vertically or obliquely under the surface of the soil. They possess distinct nodes and internodes, and bear scale leaves at the nodes. Occasional buds occur in the axils of the scale leaves. They bear slender adventitious roots on their surface. The rhizomes may be unbranched bearing a bud at the growing end, or branched, each branch ending in a terminal bud. Examples of rhizome drugs include Arnica, Ginger, Hydrastis, Liquorice, Male Fern, Podophyllum, Rhubarb, Tumeric and Valerian. 87 RHIZOME 88  CORMS These are condensed forms of rhizomes consisting of stout, solid, fleshy underground stems growing vertically. They are usually more or less rounded in shape or often somewhat flattened. Corms bear one or more buds in the axils of scale leaves. They produce adventitious roots on their under surface and also on their sides. Colchicum corm is a good example of corm drug. 89 90  BULBS They consist of a shortened convex or slightly conical stem, a terminal bud and numerous scale leaves. The scale leaves grow from the upper surface of the stem, while a cluster of adventitious roots arise from its base. Examples of drugs from bulbs include: Garlic, Onions and Squill. 91 92  INTERNAL CHARACTERS OF ROOTS The transversely cut surface of the root reveals characteristic features by which a monocotyledonous root can be distinguished from a dicotyledonous one. In the dicotyledons, to which most root drugs belong, there is a central woody core surrounded by the cambium, a cylinder of secondary phloem and external layer of cork. In monocotyledons, a central pith is usually present and is often composed of thick-walled lignified cells; the xylem porous and a cortex is present. 93 94  INTERNAL CHARACTERS OF RHIZOME AND CORMS They have general internal structure similar to that aerial. But they do not have any well-developed column of xylem tissue in the form of a central wood, a useful character which helps to distinguish rhizomes from roots. The transversely cut surface of a rhizome is always characteristic, which can be successfully employed to distinguish between drugs derived from different groups of plants. 95  Drugs of cryptogamic rhizomes show a number of separate steles; the dicotyledonous rhizomes have a circle of vascular bundles and a central pith, whereas in the monocotyledonous rhizomes the vascular bundles are scattered throughout the stele and cortex, and an endodermis is evident. In the unpeeled rhizomes and corms either an epidermis or a few layers of thin-walled cork cells constitute the outer part. The cortex usually consists of thin-walled parenchyma cells containing food reserves like starch, inulin and hesperidin. 96 ROOTS OF PHARMACOGNOSTIC IMPORTANCE 97  RAUWOLFIA Synonyms: Rauwolfia serpentine, Roauwolfia root, Indian Snake root, Sarpagandha, Chhotachand. Botanical source: African Rauwolfia consists of the dried roots of Rauwolfia vomitora family Apocynaceae Geographical source: The plant is widely distributed in tropical Africa including southern part of Nigeria. 98 MACROSCOPICAL CHARACTERS OF RAUWOLFIA Drug of Rauwolfia consists of mostly small pieces, which are 2 to 15 cm long and 3 to 22 mm diameter. Pieces are cylindrical. Outer surface is greyish yellow, pale brown or brown. Fracture is short. Fracture surface show yellowish to brown bark and dense pale yellow radiating wood with 2 to 8 annular rings occupying nearly three fourth of the diameter. Odour is Odorless. Taste bitter. 99 RAUWOLFIA 100 MICROSCOPICAL CHARACTERS OF RAUWOLFIA The bark is composed of stratified cork with alternating bands of smaller and larger suberized cork cells. These cork cells are isodiametric in surface view. The phloem consists of narrow rays of sieve tubes and parenchyma and alternates with broader medullary rays, which are 2 – 4 cells wide. The parenchyma contains small starch grains and prisms of calcium oxalates 101 CHEMICAL CONSTITUENTS/ MEDICINAL USES OF RAUWOLFIA Constituents: The principal constituents of African Rauwolfia are reserpine, rescinnamine. Other minor alkaloids found in this drug are ajmaline, yohimbine and alstonine. Medicinal Uses: 1. Rauwolfia is used as hypotensive and tranquillizer. 2. Reserpine being the main alkaloid is responsible for the activity and is used in anxiety condition and other neuropsychiatric diseases. 3. Sedative 4. The decoction of root is used to increase uterine contraction in difficult cases. 5. Febrifuge 102  ACONITE Synonyms: Aconitum, Aconite Root, Radix Aconiti Botanical source: Aconite consists of the dried tuberous roots of Aconitum napellus Linn., a perennial herb of the family Ranunculaceae. Geographical source: Aconite is obtained from plants cultivated in England and from wild plants growing in the mountain slopes of Germany, Switzerland and France. 103  MACROSCOPICAL CHARACTERS OF ACONITE The root is conical in shape, 4 to 10 cm long and 1 to 3 wide at the crown. The surface exhibits longitudinal ridges and numerous rootless. One or more daughter roots occur attached to the parent root. An apical bud is present at the top of the daughter root, and the base of an aerial stem is attached to the crown of the parent root. It is tarchy fractured surface. The whole root has a short fracture with a starchy fractured surface, the transversely cut surface shows a stellate cambium. It has a slight taste with a tingling and numbing sensation104 ACONITE 105  MICROSCOPICAL CHARACTERS OF ACONITE The outer brown tissue consists of suberized parenchymatous cells. The cortex is about 20 cells wide bounded inside by endodermis with suberized radial walls. Some characteristic sclereids occur in the cortex. Xylem tissues of the radial vascular bundles are composed of small groups of pitted and reticulate vessels embedded in parenchyma. The pith is large and composed entirely of parenchymatous tissue containing starch grains. 106 CHEMICAL CONSTITUENTS/ MEDICINAL USES/ ADULTERANT OF ACONITE Constituents: Aconite principally contains three closely related alkaloids, namely: aconitine, picraconitine and aconine. It also contains small amounts of other alkaloids, aconitic acid and starch. Uses: Tinctures of aconite and aconitine are used externally in certain forms of neuralgia and rheumatism, and internally in small doses in cases of fever and pain. Substitutes and Adulterants: The common substitutes and adulterants of Aconite include dried roots of Aconitum uncinatum var. japonicum (Japanese Aconite) A. deinorhizum (Indian Aconite), A. tianshanicum (Russian Aconite), A. heterophyllum (Atis root) and A. chasmanthum. 107  IPECACUANHA Synonyms: Ipecac, Ipecacuanha root, Radix ipecacuanhae. Botanical Source: Ipecac consists of the dried root of Cephaelis ipecacuanha or of Cephaelis acuminata, belonging to family Rubiaceae. Gepographical source: The drug is obtained from plants growing both wild and cultivated in the forests of Brazil. It has been successfully produced by cultivation in West Bengal, Burma, Singapore and Malaysia. 108  MACROSCOPICAL CHARACTERS OF IPECACUANHA The rhizome is thin or sometimes thick and annulated. Ipecac is 5–15 cm long, 6 mm in diameter, shape is cylindrical, external surface is broadly annulated, Colour is brick red to brown in colour, The ridges are rounded and encircle the root, fracture of root is short and shows a thick, greyish bark and small dense wood. Odour is slight and taste is bitter and acrid. 109 IPECACUANHA 110  MICROSCOPICAL CHARACTERS OF IPECACUANHA A transverse section of the root shows a thin, brown cork, the cells of which contain brown, granular material. There is a wide, secondary cortex (phelloderm), the cells of which is parenchymatous and contains starch in compound grains with raphides of calcium oxalate. The phloem is parenchymatous, containing no sclerenchymatous cells or fibres. The compact central mass of xylem is composed of small tracheidal vessels, tracheids, substitute fibres, xylem fibres and xylem parenchyma. Starch is present in the xylem parenchyma and in substitute fibres. 111 CHEMICAL CONSTITUENTS/ MEDICINAL USES/ ADULTERANT OF IPECACUANHA Constituents: Ipecac root contains 2–3% of total alkaloids. These include emetine, cephaeline, psychotrine and methyl psychotrine, emetamine Chemical Test of Emetine: Powdered drug (0.5 g) is mixed with HCl (20 ml) and water (5 ml), filtered and to the filtrate (2 ml) potassium chloride (0.01) is added. If emetine is present, a yellow colour develops which on standing for 1 hour gradually changes to red. Uses: Ipecac is an emetic, used as an expectorant, diaphoretic and in the treatment of amoebic dysentery. Adulterants: The drug is often substituted by stem and roots of Calotropis gigantea and others. The powdered drug is often adulterated with almond meal. 112  GENTAIN Synonyms: Gentiana, Gentain Root, Gentinae Radix Botanical source: Gentian consists of the dried roots and rhizomes of Gentiana lutea Linn. a herbaceous perennial plant of the family Gentianaceae. Geographical source: The plant is indigenous to central Europe and the drug is exported from Spain. 113 GENTIAN 114  MACROSCOPICAL CHARACTERS OF GENTIAN The drug occurs in nearly cylindrical pieces, often 50 cm or more long and up to 2.5 cm thick. It is sometimes longitudinally split. There are longitudinal wringles on the cork of the root, while the rhizome is encircled by crowded leaf-scars. It is yellowish-brown in colour and breaks with a short fracture showing a starchy surface. The transversely cut surface is almost uniformly reddish- yellow in colour with a distinct cambium and a radiate wood. A pith is present in the rhizome. The drug has charactersistic odour and a characteristic taste which is sweet at first and then persistently bitter. 115  MICROSCOPICAL CHARACTERS OF GENTAIN The cork consists of several layers of thin-walled tangentially elongated cells containing oil globules. Cortex is narrow and is made up of tangentially elongated collenchymatous cells containing a brownish granular substance, oil globules and minute needle-shaped calcium oxalate crystals. The outer phloem tissue consists of large cells with intercellular spaces and prominent nuclei. All phloem cells contain oil globules and minute needles of calcium oxalate. Xylem tissue consists principally of parenchymatous cells transversed by medullary rays. The also contain oil globules and minute needles of calcium oxalate. The vessels occur scattered, either isolated or in small groups, in the parenchymatous tissue. 116 CHEMICAL CONSTITUENTS/ MEDICINAL USES/ ADULTERANT OF GENTAIN Constituents: Gentian contains a number of bitter glycosides including oentiopicrin, gentian and gentiamarin. It also contains sugars like gentianose and sucrose, enzymes, a yellow colouring matter, pectin and oil. Uses: Gentian is used as a favourite tonic. Substitutes and adulterants: The dried roots and rhizomes of the following plants are frequently used as substitutes and adulterants of Gentian: Gentiana purpurea, Gentiana pannonica, Gentiana punctura, Rumex alpinus (Polygonaceae) and Veretrum album (Veretraceae). 117  JALAP Synonyms: Jalapa, Jalapae Radix Biological source: Jalap consists of the dried tubercules of Ipomoea purge Hayne, a climbing, twining plant of the family Convulvulaceae Geographical source: It is indigenous to Mexico and cultivated in India. 118  CHEMICAL CONSTITUENTS/ MEDICINAL USES/ ADULTERANT OF JALAP Constituents: It contains glycosidal resin (8 to 20 %). Other constituents include: mannitol, sugars, starch, beta-methylaesculetin and calcium oxalate. Uses: Jalap is used as a hydragoque cathartic. In smaller doses, it acys as a laxative and in large doses it causes purgation. Substitutes and adulterants: Ipomoea simulans, Ipomoea orizabensis and Mirabilis jalapa. 119  BELLADONNA Synonyms: Belladonnae Radix, Deadly Nightshade Root Botanical source: Dried roots and root stocks of Atropha belladonna Linn. of the family Solanaceae. Geographical source: Cultivated in England, Rumania, Bulgaria, Germany and U.S.A. 120 BELLADONNA 121 CHEMICAL CONSTITUENTS/ MEDICINAL USES/ ADULTERANT OF BELLADONNA Constituents: It mainly contains the tropane alkaloid hyoscyamine and small quantity of hyoscine. It also contains a crystalline fluorescent compound, β-methyl aesculetin, tannin, starch and calcium oxalate. Uses: Belladonna extract is externally used as a local anaesthetic and anodyne. Interally it is used to check sweating and other glandular secretions, as sedative, antispasmodic and mydriatic gent. Substitutes and adulterants: Atropha acuminate (Indian Belladonna), Phytolacca decandra, Scopolia carniolaca and Scopolia japonica. 122  RHIZOME OF PHARMACOGNOSTIC IMPORTANCE 123  GINGER Synonyms: Zingiber, Rhizoma Zingiberis Botanical source: Ginger consists of the dried rhizomes of cultivated Zingiber officinale Roscoe devoid of their dark outer skin. The plant is a perennial herb of the family Zingiberaceae. Geographical source: Ginger plant is indigenous to south-eastern Asia and is cultivated in may tropical countries, notably in Jamaica (the official drug), Bangladesh, India, Nigeria and many other African countries. 124  MACROSCOPICAL CHARACTERS OF GINGER The rhizomes are 5 to 15 cm long, 3 to 6 cm wide and about 1.5 cm thick. The outer surface has slight yellow colour with longitudinally striated fibres. Small circular depressions at the portion of the buds are seen. The ginger has agreeable and aromatic odour and pungent and agreeable taste. 125 126  MICROSCOPICAL CHARACTERS OF GINGER The cork is the outermost layer with irregular parenchymatous cells and dark brown colour. The inner cork is few layered, colourless parenchymatous cells arranged in radial rows. Cork is absent in Jamaica ginger. Phellogen is indistinct and the cortex consists of thin-walled rounded parenchyma with intercellular spaces consisting of abundant starch grains. The starch grains are simple, ovate, or sac shaped. 127  Numerous yellowish brown oleoresins are also present along with the collateral fibro vascular bundles. The endodermis is distinct without starch and consists of single layer of tangentially elongated cells containing suberin. Just below the endodermis it has the ground tissue, a ring of narrow zone of vascular bundle which is not covered with sclerenchymatous fibres. The ground tissues contain the large parenchymatous cells rich in starch, oleoresin, and fibro vascular bundles. The phloem has well-developed sieve elements, and the xylem consist of vessels, tracheids either annual or spiral, or reticular in nature without lignin. The fibres are unlignified, pitted, and separate. 128  CHEMICAL CONSTITUENTS/ MEDICINAL USES OF GINGER Constituents: Ginger contains 1 to 2% volatile oil, 5 to 8% pungent resinous mass and starch. The volatile oil is responsible for the aromatic odour and the pungency of the drug is due to the yellowish oily body called gingerol which is odourless. α -zingiberol, gingerone. Uses: Ginger is used as an antiemetic, positive inotropic, spasmolytic, aromatic stimulant, carminative, condiment, and flavouring agent. It is prescribed in dyspepsia, flatulent colic, vomiting spasms, as an adjunct to many tonics and stimulating remedies, for painful affections of the stomach, cold, cough, and asthma. Sore throat, hoarseness, and loss of 129 voice are benefited by chewing a piece of ginger.  ADULTERANT OF GINGER Adulteration: Ginger may be adulterated by addition of ‘wormy’ drug or ‘spent ginger’ which has been exhausted in the extraction of resins and volatile oil. This adulteration may be detected by the official standards, for alcohol-soluble portion, water soluble portion, total ash and water-soluble ash. Sometimes pungency of exhausted ginger is increased by the addition of capsicum 130  TURMERIC Synonyms: Turmeric Rhizome, Curcumae Rhizoma Botanical Source: Turmeric consists of the boiled and dried whole or split and unpeeled rhizome of Curcuma domestica Val. And Curcuma longa Linn. of the Zingiberaceae. Geographical source: Turmeric is obtained from plants cultivated in India, China, Indonesia, Bangladesh and other Asian countries. 131  MACROSCOPICAL CHARACTERS OF TURMERIC Turmeric occurs in whole forms as ‘fingers’ and ‘bulbs’ or longitudinally split pieces. The fingers and bulbs are cylindrical or sub- cylinderical in shape, bluntly tapering at both ends. The outer surface is deep yellowish-brown in colour, longitudinally wrinkled and marked with transverse rings of scars of scale leaves. Short knob-like branches and large circular scars of broken off branches often occur on the surface. The drug is hard and heavy and breaks with a short fracture. 132 TURMERIC 133  MICROSCOPICAL CHARACTERS OF TURMERIC Internally, the drug is uniformly dull brownish- yellow in colour with a waxy appearance. The transversely cut surface shows a paler or darker endodermal ring separating the stele from the cortex, in both of which numerous fibrovascular bundles remain scattered. The ground tissue is made up of parenchymatous cells which contain masses of gelatinized starch grains. The drug has characteristic aromatic odour and somewhat bitterish unpalatable taste. 134  CHEMICAL CONSTITUENTS/ MEDICINAL USES OF TURMERIC Constituents: Turmeric contains about 5 % of volatile oil, about 5 % of crystalline yellow substance, curcumin. It also contains resin, sugars and starch. Uses: The drug is used locally as a blood-purifier, a colouring and dyeing agent, and also as a condiment in cooking. 135  PODOPHYLLUM Synonyms: Phodophyllum Rhizome, Podophylli Rhizoma, May apple Root, African Mandrake. Botanical source: Podophyllum consists of the rhizome of Podophyllum peltatum Linn., a low growing woodland plant of the family Berberidaceae. Geographical source: The drug is obtained from plants growing in eastern U.S.A and eastern Canada 136 CHEMICAL CONSTITUENTS/ MEDICINAL USES ADULTERANT OF PODOPHYLLUM Constituents: Podophyllum mainly contains a crystalline substance, podophyllotoxin, and a resin, podopylloresin (podophyllin). It also contains quercetin and abundant starch. Uses: Phodophyllum is a gastro-intestinal irritant which in moderate doses acts as a drastic purgative. It is used in the treatment of constipation from hepatic trouble. A paint of Phodophyllum is used in the treatment of warts. Substitutes and adulterants: The rhizome of Phodophyllum emodi Wall. (Indian Phodophyllum) is a good substitute of official Phodophyllum. Rhizomes of other species of Phodophyllum are used as adulterants of the drug. 137  LIQUORICE Synonyms: Liquorice root, Glycyrrhiza, Glycyrrhizae Radix Botanical Source: Liquorice is derived from the stolons and roots of Glycyrrhiza glabra Linn. and other species of the genus Glycyrrhiza of the fanily Leguminosae. Geographical source: Liquorice is grown in the sub-Himalayan tracts and Baluchistan. It is cultivated on a large scale in Spain, Sicily and Yorkshire (England). 138 LIQUORICE 139  CHEMICAL CONSTITUENTS OF LIQUORICE Chemical constituents: Liquorice contains 5 to 7 % of glycyrrhizin (a sweet principle made up of potassium and calcium salts of glycyrrhizic acid). It also contains glucose, sucrose, a bitter principle, starch, fat and calcium oxalate. 140  MEDICINAL USES OF LIQUORICE 1. Glycyrrhiza has demulscent and expectorant properties 2. It is used as a masking agent for bitter drugs in pharmaceutical formulations, such as: quinine, aloe, ammonium chloride etc. 3. Ammoniated glycyrrhiza is employed as a flavouring agent in beverages, pharmaceuticals and confectionary. 4. The inherent surfectant activity due to the presence of saponins helps to facilitate the absorption of poorly absorbed drugs, for instance: anthraquinone glycosides. 5. The presence of glycyrrhetinic acid exert mineralocorticoid activity and hence it is used in the treatment of inflamations, rhematoid arthritis and Addison’s disease. 141  MALE FERN Synonyms: Filix Mas, Aspidium, Male fern Rhizome Botanical source: Male fern consists of therhizome, frond bases and apical buds of Dryopteris filix-mas (Linn.) Sch., a fern of the family Polypodiaceae (Pteridophyte). Geographical source: Male fern grows abundantly in Britain and other central European countries. 142 MALE FERN 143 CHEMICAL CONSTITUENTS/ MEDICINAL USES ADULTERANT OF MALE FERN Constituents: Male fern contains chemical substances like filmarone, flavaspidinol, fillicitannic acid, fillicin, flavaspidic acid resin and starch. Uses of male fern: It is used to treat nosebleeds, heavy menstrual bleeding, wounds, and tumors. It is also used to expel worms, typically tapeworms, from the intestines. Some veterinarians use male fern to treat worms in animals. Substitute and adulterants of male fern include: Rhizomes of Athyrium filix-foemina and Dryopteris spinulosa. 144  RHUBARB Synonyms: Rheum, Rhei Rhizoma, Rhei Radix, Rhubarb Rhizome Botanical source: It consists of the dried rhizome of various Rheum species, particularly Rheum palmatum Linn. and Rheum officinale. Baillon of the family Polygonacae. Geographical source: China and Tibet 145  CHEMICAL CONSTITUENTS/ MEDICINAL USES AND ADULTERANT OF RHUBARB Constituents: It contains 2 to 4.5 % anthraquinones derivatives which include chrysophanol, emodin aloe- emodin and rhein. It also contains glucogallin, rheinolic acid, starch, sugars, fat, pectin and calcium oxalate. Uses: It is used as laxative drug. In large doses it causes purgation. In smaller doses it is a bitter stomachic and intestinal astringent. It is also given in cases of indigestion with diarrhea. Substitutes and adulterants: Indian Rhubarb (R. emodi) and English Rhubarb (Rheum officinale) are used as substitutes; while Rhapontic Rhubarb and others are used as adulterants. 146  CORMS OF PHARMACOGNOSTIC IMPORTANCE 147  COLCHICUM Synonyms: Colchicum Corm, Colchicum Root, Colchici Cormus, Colchici Radix. Biological Source: Colchicum consists of the fresh or dried corm of colchicum autumnale Linn. (Family Liliaceae), deprived of its coats. Geographical source: The plant grows throughout Europe, particularly in England, Holland and Italy. 148  MACROSCOPICAL CHARACTERS OF COLCHICUM The fresh whole corm is ovoid or sub-conical in shape, about 4 cm long and 3 cm broad. The dried slices are reniform, vary in width from 2 to 3 cm and average thickness in 4 mm. The corm is crowned with bases of flowering stem at the apex, a small bud near the base on the flattened side and fibrous roots at the base. The dried slice exhibits a thin, brown, membranous epidermis and numerous fibrovascular bundles as brown spots against a white ground tissue. It has a short fracture with a mealy fractured surface. The drug has got no odour, but possesses a very bitter acrid taste. 149 COLCHICUM 150  MICROSCOPICAL CHARACTERS OF COLCHICUM The epidermal cells are rectangular to polygonal in shape and have brown, thick and slightly wavy walls. The epidermis contains occasional circular stomata. The major bulk of the corm is made up of thin-walled rounded parenchymatous cells filled with abundant simple or compound starch grains. Muller-shaped starch grains often occur. Vascular bundles are slender and collateral and run longitudinally through the corm. Xylem vessels are narrow with spiral or annular thickening. 151  CHEMICAL CONSTITUENTS/ MEDICINAL USES OF COLCHICUM Constituents: The drug consists an almost neutral toxic alkaloid, colchicine (about 0.6 %) and abundant starch grains. Uses: Colchicum is mainly used to treat acute attack of gout and certain other gouty affections. It relieves the pain and inflammation, and shortens the duration of the disease. The alkaloid, colchicine, induces polyploidy in plants by arresting spindle formation during mitotic cell division. 152 BULBS OF PHARMACOGNOSTIC IMPORTANCE 153  SQUILL Synonyms: Scilla, Scillae Bulbus, Scillae Radix Botanical source: Squill consists of the sliced and dried fleshy scale leaves of the bulb of Urgenia maritima (Linn.) Baker (= U stein) of the monocotyledonous family Liliaceae. Geographical Source: Squill is largely obtained from Malta and the countries of the Meiterranean coast. 154  MACROSCOPICAL CHARACTERS OF SQUILL The dried slices of the bulb scales occur in concavo- convex curved strips, frequently tapering at both ends, 1 to 5 cm long. They are slightly translucent and pale yellow in colour with longitudinal furrows. The dried pieces are brittle and have a short fracture. But they are tough and flexible when moist. The fractured surface is mucilaginous. 155 SQUILL 156  The transversely cut surface shows a number of scattered vascular bundles. The drug has slight odour and possesses a bitter, mucilaginous and acrid taste. Occasionally, the entire fresh bulb is sold in the market. The entire bulb is ovoid in shape, 18 to 20 cm high and 12 to 15 cm in diameter. It is often crowned with the bases of the aerial leaves at the upper end and bases of the adventitious roots at the lower end, the dry thin scale leaves of the bulb are removed during cleaning of the drug. 157  MICROSCOPICAL CHARACTERS OF SQUILL The epidermal cells are axially elongated and quadrangular or polygonal in shape. Nearly circular stomata are present on the lower (outer) surface of the scale leaves in very small number, they also occur very rarely on the upper (inner) surface. The bulk of the mesophyll tissue is made of parenchymatous cells, some of which are occasionally filled with raphides of calcium oxalate embedded in mucilage. 158  Vascular bundles are also present in the mesophyll. They are composed of spiral vessels and phloem with parenchyma in between. Rarely rounded starch grains and prisms of calcium oxalate occur in the mesophyll tissue. The powdered drug is yellowish-white in colour and contain abundant, large, thin-walled cells of the mesophyll parenchyma. Idioblasts containing raphides of calcium oxalate and mucilage are present in the powder. Free single acicular crystals and very occasional prisms of calcium oxalate are also present in the powdered drug. 159  CHEMICAL CONSTITUENTS/ MEDICINAL USES ADULTERANT OF SQUILL Constituents: Squill contains a number of cardiac glycosides which include: Scillaren A (a pure crystalline substance) and scillaren B (an amorphous mixture of glycosides). It also contains xanthoscillide, sinistrin, mucilage (4 to 11 %) and calcium oxalate. Uses: as stimulant, expectorant, cardiac tonic and duiretics Substitute: The fleshy scale-leaves of Urgenia indica, the indian Squill, is a good substitute of the European Squill 160  ONION Biological Source: Allium cepa Linn. Family: Alliaceae Synonym: Allium ascalonicum Geographical Source: It probably originates from Central Asia (between Turkmenistan and Afghanistan) Characteristics Onions are the indispensable vegetable, the strong (yet sweet) cornerstone of modern cooking, not just in our culture but around the world. Whether it's a soup, stew, stir-fry, salad or sauce, chances are the recipe includes onions or garlic (very likely both) or one of their relatives. These members of the Allium genus (part of the lily family) don't just add flavour, they add richness and complexity. 161  MACROSCOPICAL CHARACTERS OF ONION The onion is an edible bulb. While it is a vegetable at heart, it also acts as a spice inasmuch as it can provide an aromatic undertone to various meat and vegetable dishes, without being a major ingredient. The characteristic appearance of the onion is well known, but there are many variations of colour, shape and size. 162 ONION 163  The colour varies from white to red to purple, the shape from spherical to almost conical. The diameter at the largest point from 10mm (1/2in) to 8cm (3in) or 'more. The papery skin should be tight over the surface of the bulb. Spring onions, or scallions, are immature plants where the bulb has not completely formed. They may be cylindrical, the green stem shading into the white bulblet, which may be almost spherical. Onions are also available in processed form, as dried flakes and powder, or liquid. 164  CHEMICAL COMPOSITION OF ONIONS Onion contains protein, sugars, cellulose, minerals, a fixed oil, an essential oil and over 80 per cent water. The amount of essential oil is very small but it contains the aromatic and tear-producing properties associated with onion. These are caused by sulphides which are produced by the reaction of the enzyme alliinase on an amino acid. These substances are normally in separate cells in the tissues, but when the onion is cut and bruised, rupturing the cells, the reaction takes place. Cooking has the opposite effect, preventing the enzymatic action and thus milder and less pungent flavours are produced. 165  MEDICINAL USES OF ONION Antiseptic, diuretic, expectorant and rubefacient. Onion's antiseptic properties as a juice or paste have been used for wound healing, skin complaints (acne), insect bites, hemorrhoids, boils, toothache, earache and respiratory complaints. The raw juice is diuretic and the whole onion is an appetite stimulant and digestant. It has been used as a vermifuge. It is believed to stimulate the liver and is beneficial to the heart and nervous system 166  GARLIC Synonym: Allium Biological Source: Garlic is the ripe bulb of Allium sativum Linn., belonging to family Liliaceae. Geographical Source: Garlic occurs in central Asia, southern Europe, and United States. It is widely cultivated in India. Characteristics: It is a perennial herb having bulbs with several cloves, enclosed in a silky white or pink membraneous envelope. 167 GARLIC 168  CHEMICAL COMPOSITION OF GARLIC Allicin, a yellow liquid responsible for the odour of garlic, is the active principle of the drug. It is miscible with alcohol, ether, and benzene and decomposes on distilling. The other constituents reported in Garlic are alliin, volatile and fatty oils, mucilage and albumin. Alliin, another active principle, is odourless, crystallized from water acetone and practically insoluble in absolute alcohol, chloroform, acetone, ether, and benzene. 169  Upon cleavage by the specific enzyme alliinase, an odour of garlic develops, and the fission products show antibacterial action similar to allicin. Essential oil (0.06–0.1%) contains allyl propyl disulphide, diallyl disulphide, and allicin. γ-Glutamyl peptides are isolated from the Garlic. The amino acids present in the bulb are leucine, methionine, S-propyl-L-cysteine, S-propenyl-L- cysteine, S-methyl cysteine, S-allyl cysteine sulphoxide (alliin), S-ethyl cysteine sulphoxide, and S-butyl-cysteine sulphoxide. 170  MEDICINAL USES OF GARLIC Garlic is carminative, aphrodisiac, expectorant, stimulant, and used in fevers, coughs, febrifuge in intermittent fevers, respiratory diseases such as chronic bronchitis, bronchial asthma, whooping cough, and tuberculosis. It is also used in atherosclerosis and hypertension. In Germany, garlic is consumed as a complement in the diet of hyperlipidemic patients and for the prophylaxis of the vascular changes induced by ageing. The garlic can cause gastrointestinal distress and alters breath and skin odour. Garlic or its constituents exhibit various biological activities, such as antibacterial, antifungal, antiviral, antitumor, and antidiabetic effects. 171 THANK YOU 172