Leaves - Natural Medicinal Drugs (PDF)

Natural Medicinal Drugs Natural medicinal drugs may fall under one of the following classes: Leaves or leaflets. Herbs. Barks. Woods. Inflorescences and flowers. Fruits. Seeds. Subterranean Organs. Fungus Unorganized drugs. Drugs of Animal origin. Leaves or Leaflets Senna L...

Natural Medicinal Drugs Natural medicinal drugs may fall under one of the following classes: Leaves or leaflets. Herbs. Barks. Woods. Inflorescences and flowers. Fruits. Seeds. Subterranean Organs. Fungus Unorganized drugs. Drugs of Animal origin. Leaves or Leaflets Senna Leaflets Digitalis leaves Herbs Datura Ephedra  Barks Cinnamon Cinchona Inflorescences and Flowers Chamomile Clove Fruits Ammi visnaga Anise Seeds Nxvomica Linseed LinSeed Subterranean Organs Ginger Liquorice Sclerocia of Fungus ( Ergot ) Ergot ergot2b Unorganised Drugs Myrrh Gum arabic  The Leaf (Folium) The leaf is a lateral outgrowth on the stem from which it differs in structure. It is usually flattened, having one or more buds in its axil. It possesses neither nodes nor internodes and usually bearing, no branches or leaves. Types of leaves: 1- Cotyledons (seed leaves) 2- Prophylls (fore leaves) 3- Foliage leaves 4- Bracts 5- Floral leaves 6- Scale leaves 7- Modified leaves 1- Cotyledons (seed leaves) 2- Prophylls (fore leaves) 3- Foliage leaves 4- Bracts 5- Floral leaves 6- Scale leaves Insertion Foliage leaves may be described as: A- Radical: the leaves crowded together about the top of the root at the level of ground or just above it B- Cauline: the leaves spread apart on the elongated aerial stem Leaf morphology 1- Leaf base 2- Petiole (Stalk) 3- Blade (Lamina) a- Type (simple, lobed or compound) b- Shape c- Apex d- Margin e- Base of lamina f- venation  Leaves and Leaflets For Description of Leaf Drugs one must perform:. I- Macroscopical Examination Duration (deciduous or evergreen). Composition (simple or compound whether palmate, paripinnate or imparipinnate). Insertion ( radical or cauline ). Phyllotaxis ( alternate, opposite, whorled, opposite decussate). Leaf base (stipulate or exstipulate, symmetric or asymmetric). Petiole ( Petiolate or sessile). Lamina phyllotaxis of leaves 1- Alternate: the leaves inserted singly at the node 2- Opposite: the pair of leaves inserted at each node, the leaf is opposite of each other 3- Decussate: the leaves are opposite, and each pair is inserted at right angle to the pairs immediately above and below it. 4- Whorled: three or more leaves occur at each node and arise in a circle around the stem Petiole and Stipules Petiolate i Sessile 1- Leaf base A- Stipulate B- Exstipulate  Base of lamina 1- Symmetric 2- Asymmetric 3- Decurrent 4- Cordate Blade (Lamina) A- Type (simple, lobed or compound) - Simple: The lamina consist of continuous, undivided surface - Lobed or divided: The lamina is cut into a number of lobes connected together - Compound: The lamina is cut completely into a number of separate leaflets (pinnae) Compound Pinnate Leaves Imparipinnate(left) and paripinnate(right) Leaves and Leaflets Lamina: - Incision (if incised [sect.,fid,partite] pinnatisect……. or palmatisect…. - Shape (acicular,elliptical,oval,lanceolate,spathulate) - Venation (parallel, pinnate,palmate,reticulate)Notice the vein islets. - Margin (entire,serrate,dentate,crenate) - Apex (acute,acuminate,mucronate,truncate,acute) - Base (symmetric,asymmetric) - Surface (glabrous or pubescent) - Texture (brittle,fleshy,coriaceous) Incision Palmately lobed Pinnately lobed Simple palmately-lobed leaf Shape Margin Venation Apex Acute Acuminate Mucronate Obtuse Leaf Base Symmetric Asymmetric Shape of Dicot. and Monocot.Leaves II-Microscopical Examination (Anatomy) Transverse section in the leaf differs in monocot leaves than in dicot. ones. Monocot leaves: example, squill. Dicot. leaves: example, senna, buchu, digitalis, coca.  Anatomy of Leaves The leaf is built up of the following: Protective epidermis (upper and lower). Mesophyll consisting of: - Palisade *upper and lower in isobilateral leaves. *upper layer only in dorsiventral leaves. - Spongy tissue. - Occasional scelerenchyma in the midrib region. Vascular system( mid rib and lateral veins) Leaf Anatomy TS in Monocot. leaf TS. In Dicot. Leaf Dorsiventral leaf Isobilateral Leaf  Some Important Leaf Drugs Senna Digitalis Buchu Eucalyptus Jaborandi Ginkgo biloba Uva ursi Boldo Vinca Coca Guava Tilia Henna