Pharmacognosy-2 Lecture 6 (Subterranean Organs-I) Lecture Notes PDF

Pharmacognosy-2 Subterranean organs Lecture 6 Dr. Amal F. Soliman, PhD Associate professor of Pharmacognosy Dr. Walaa Safwat , PhD Lecturer of Pharmacognosy  Subterranean Organs Subterranean Organs Include: 1- Subterranean Stems (Rhizomes, corm...

Pharmacognosy-2 Subterranean organs Lecture 6 Dr. Amal F. Soliman, PhD Associate professor of Pharmacognosy Dr. Walaa Safwat , PhD Lecturer of Pharmacognosy  Subterranean Organs Subterranean Organs Include: 1- Subterranean Stems (Rhizomes, corms, stem tubers and bulbs). 2- Subterranean Roots (roots and root tubers). They serve as storage organs for the plant, so they are full of reserve food material such as starch, inulin (Compositae) and sugars. They are devoid of chlorophyll.  There is no clear division between rhizomes and roots in commercial sense. Hence commercial rhizomes always contain a considerable proportion of root and similarly commercial roots often consists of rhizome. Subterranean organs in medicine are usually collected from perennial plants, where they serve as storage organs.  Collection and Drying of Medicinal Roots and Rhizomes They are collected when they are full of reserved food material (the active constituents at the highest conc.) most often in autumn. ‫لالطالع فقط‬ Large roots and rhizomes are transversely or longitudinally sliced to facilitate drying. Gentle artificial heat is applied first then temperature is increased gradually till complete drying (crispy fracture). Sun heat is used in tropical regions.  Marketing Medicinal Roots and Rhizomes Medicinal roots and rhizomes occur in the market dried as: Entire roots (Senega). Sliced transversely (Calumba). ‫لالطالع فقط‬ Sliced longitudinally (Althea). Broken pieces (Ginger). Peeled or decorticated (as in some Liquorice and Ginger).  1- Subterranean Stems These are characterized by: Externally: Scaly leaves inclosing axillary buds. Adventitious roots. Nodes and internodes Having a growing point protected by scale leaves forming a bud (terminal bud). Internally: Never having solid central mass of xylem. In dicots, there are central parenchymatous pith.  1- Subterranean Stems Rhizomes, Corms, Stem Tubers, Bulbs I. Rhizomes: The most important group. They grow horizontally (rarely vertically or oblique) with roots on the inner side and having: - Nodes and internodes. - Terminal buds and aerial shoots. - May be branched a. Sympodially e.g. Ginger b. Monopodially e.g. Filix mas  Types of Rhizomes A Stolon is an underground stem travelling near or below the surface of the soil giving roots at its extremity (e.g., liquorice). It is similar in function to a runner, but it is much thicker. A Sucker is a branch growing under the ground and giving up roots and aerial shoots at each node (e.g., mentha). A Sobole which is a rapidly growing rhizome and is long, thin, tough with long internodes (e.g. dog grass). Stolon Sucker Sobole II- The Corm: is a shortened swollen erect underground stem, covered with a brown scaly leaves arising at the nodes (e.g. Colchicum, Colcasia). III- The Stem Tuber: is a swollen underground stem differing from the several small scales and root tuber in bearing buds (called eyes) as well as a terminal bud in the free end (e.g., Potato). It is full of food material and serve for vegetative propagation. VI- The Bulb: is an underground stem which is reduced to a small flat disc and is crowned with crowded fleshy scaly leaves and having adventitious roots arising from the base of the bulb. It may be: ▪ Tunicate bulb (with outer scales is larger and completely enclosing the inner fleshy ones( e.g., Onion. * The bulb of garlic is a compound tunicated bulb (each fleshy scale is surrounded by its white tunic).  2- Roots The root is that portion of the plant axis which in the seedlings grows vertically downwards in the soil. It doesn’t show nodes and doesn’t bear leaves or buds. The root is usually constructed of four zones. ▪ The root cap ▪ The zone of elongation ▪ The zone of absorption ▪ The zone of lateral branches  Types of Roots ‫لالطالع فقط‬ Primary Roots: e.g., tap roots as in Senega. Secondary roots: which are the lateral roots as in Krameria. Adventitious roots: arising from the stem as in Ipecacuanha and Jalap. Storage roots: any of the previous types if swollen with reserved food material. Very swollen roots are called Root tubers (Jalap, Aconite).  Histology of Subterranean stems In Dicotyledonous Plants: shows a circle of open Pith vascular bundles enclosing a central pith. In rhizomes and underground stems, the pith is packed with reserved material. In Monocotyledonous Plants: Showed numerous closed V.B. which is scattered, more crowded and smaller near the periphery and larger and few in the center. Shows sclerenchymatous hypodermis.  Histology of Roots Dicot. Roots shows much wider cortex than subterranean stems sometimes covered with a piliferous layer (exodermis). Well-marked endodermis. The stele is surrounded by the pericycle and composed of a circle of alternating phloem and xylem bundles (protoxylem towards the periphery).  Pith is absent in woody roots but in herbaceous ones and in monocots, it is Dicot. root represented by thickened parenchyma or sclerenchyma. Pith Monocot. root Examples of Anomolous Structures in Medicinal Subterranean Organs In Subterranean Stems: Star Spots in Rhubarb. In Roots: Keel in Senega.  Filix mas (Male fern, Apsidium) Carefully dried rhizomes and frond bases of Dryopteris filix-mas, family Polypodiaceae Spores on the lower surface  key element of filxmas ( large, thick walled parenchymatous cells. Containing starch granules and showing large intercellular spaces, into which project unicellular glandular hairs secreting a greenish oleo-resin).  Active Constituents: ▪ 5% filmarone (to which the vermifuge properties is attributed). ▪ Filicic acid and its lactone filicin. ▪ Fixed oils. Uses: Anthelmintic (Vermifuge) (due to oleo-resin content). It has a paralytic effect on tape-worm (e.g., Taenia saginata & Taenia solium originated from raw beef and pork respectively).  Filix mas should be used with caution as in large doses, it is poisonous. It is reported to be hepatotoxic and nephrotoxic. Interactions with drugs Filix mas Castor oil  Ginseng roots The term Ginseng refers to several species of Panax family Araliaceae The two most commonly used are : 1 The American Ginseng Panax quinquefolius 2 The Asian Ginseng (Chinese, Korean) Panax ginseng  Panax quinquefolius ▪ Wrinkles around the neck of the root tell how old the plant is. This is important because ginseng is not ready for use until it has grown for four to six years.  Active Constituents: ▪ Saponins (Ginsenosides = Panaxosides). ▪ Phytoestrogens. ▪ High molecular weight Polysaccharides (glycans). ▪ Acetylenic compounds. Uses: ▪ Adaptogenic. ▪ Improves both physical and mental abilities. ▪ Aphrodisiac. ▪ Immunostimulant. ▪ Muscle relaxant. ▪ Anti-inflammatory. ▪ Treatment of type II diabetes. ▪ For menopausal disorders. ▪ Cardiotonic. ▪ Anti-oxidant. ▪ Normalize both high and low blood pressure.  Side effects: ▪ High doses of ginseng may cause nervousness or insomnia (trouble sleeping). Other reported side effects include high blood pressure, restlessness, diarrhea, vomiting, headache, nosebleed, breast pain, and vaginal bleeding. ▪ To avoid hypoglycemia (low blood sugar), even in non-diabetics, ginseng should be taken with food. Caution: 1- Use with Oral anticoagulants (e.g., warfarin) or oral antiplatelet (e.g., Aspirin) as Ginsenosides inhibit platelets aggregation. 2- Use with oral hypoglycemic drugs, insulin. 3- Ginseng is not recommended for pregnant women. Case Study: 35 years old male who presents with complaints of daily fatigue. He described going to bed at 8:00 p.m. each evening and sleeping soundly until his alarm goes off at 6:00 a.m. He is still exhausted and finds it difficult to get to work on time. At home in the evening he eat fast food he picked up on the way home. Sometimes he doesn`t eat at all. His lab work is within normal limits, and there no other symptoms to indicate hypothyroidism or other medical problems. What is your recommendation ? What history you should take? What are the side effects of the drug you recommended?  Aconite Root (Radix Aconiti, Monkshood, Wolf's bane) Dried tuberous roots of Aconitum napellus L. family Ranunculaceae Geographical Source: Britain, Germany.  Active Constituents: 0.2-1.5% terpene ester alkaloids the most important are: ▪ Aconitine (the most toxic) ▪ Picraconitine and Aconine (less toxic). In addition to other minor alkaloids. Uses: ▪ Aconite is a very potent and quick-acting poison which is now rarely used internally except in homeopathic doses (1:1 million) (The more the drug is diluted the greater is its ability to cure). ▪ Aconitine and preparations of aconite when applied to the skin cause tingling followed by numbness. They were used for the treatment of certain types of neuralgia ‫آالم االعصاب‬ and rheumatism. ▪ Internally, it causes fall in temperature, it is given in cases of fever and pain in repeated small doses.  Marsh mallow Root (Althaea Radix) Obtained from Althaea officinalis, family Malvaceae Active Constituents: ▪ Mucilage (the main constituent 25-30 %). ▪ Starch, Pectin, Flavonoids Uses: ▪ Emollient, demulcent, Antitussive for dry irritable coughs (not expectorant), treatment of sore throat (Lozenges).