Anatomy & Physiology of Medicinal Plants PDF

Anatomy & Physiology of medicinal plants (20 HRS) Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 29.  The Role of Medicinal Plants in Pharmacy  Medicinal plants play a significant role in pharmacy.  Pharmacy utilizes many...

Anatomy & Physiology of medicinal plants (20 HRS) Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 29.  The Role of Medicinal Plants in Pharmacy  Medicinal plants play a significant role in pharmacy.  Pharmacy utilizes many pure natural products derived from plants.  Pharmacists should advise patients about common medicinal plants.  Case study illustrating the relevance of medicinal plant knowledge.  How pharmacists can integrate herbal remedies into patient care.  An example of patient consultation on herbal supplements and their potential interactions.  Promoting an integrative approach to healthcare.  Hypothetical Case Study Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 29. Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 29. Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 29.  PLANTS AND DRUGS  Pharmacognosy involves the study of medical products derived from the living environment, especially plants and fungi.  A key concern: Defining a pharmaceutical plant-derived drug.  In pharmacy, a botanical drug is a product that can be:  Derived from a plant, transformed into a drug through drying certain plant parts (or the whole plant).  Obtained from a plant but no longer retains the plant's structure, containing a complex mixture of biogenic compounds (e.g., oils, resins).  The term 'drug' is linguistically linked to 'dry,' originating from the Middle Low German word 'droge.'  Isolated pure natural products used in pharmacy are not 'botanical drugs'; they are chemically defined drugs derived from nature.  Botanical drugs are typically derived from specific plant organs of a plant species. The most important plant organs for botanical drugs: Aerial parts or herb (herba)  Leaf (folia)  Flower (flos)  Fruit (fructus)  Bark (cortex)  Root (radix)  Rhizome (rhizoma)  Bulb (bulbus)  Majority of botanical drugs in use come from leaves or aerial parts.  Botanical drugs defined by species and the plant part used to produce the dried product.  Adulteration occurs when incorrect plant parts are included (e.g., aerial parts instead of leaves).  Upcoming sections: Botanical taxonomy, higher plants and their organs, morphology, and anatomy.  Focus on higher plants (Magnoliopsida); other plants like lichens, mosses, algae, mushrooms, or micro- organisms mentioned briefly.  Microscopic characteristics play a crucial role in botanical drug identification.  Modern identification methods include thin-layer chromatography, high-performance liquid chromatography, microscopic analysis, and near- infrared spectroscopy (used in large pharmaceutical companies).  TAXONOMY  The species: The principal unit in systematic biology.  Biological diversity includes >500,000 botanical species and >2 million zoological species.  Species: The fundamental unit for studying relationships among living organisms.  Systematicists: Study relationships between species.  Taxonomy: The science of naming organisms and integrating them into the existing nomenclature.  Taxon: Each named taxonomic unit.  Taxonomy helps structure biological diversity into hierarchical categories.  Hierarchical categories should ideally reflect the natural relationships between taxa.  Binomial Nomenclature: Basic unit of taxonomy and systematics.  Consists of genus and species names, e.g., Papaver somniferum.  Includes the authority, such as 'L.' for Carl von Linnaeus, who provided the first scientific description.  Species: Reflected in the species name, e.g., "somniferum" means "sleep-producing."  Genus: Group of closely related species, e.g., "Papaver" for poppies.  Family: Group of genera with shared traits, named after one of the genera, e.g., "Papaveraceae."  Order: Papaverales Class: Magnoliatae.  Subphylum: Magnoliphytina (seed-bearing plants with covered seeds).  Division: (=Phylum): Spermatophyta (seed- bearing plants).  Kingdom: Plantae (the plants), one of three kingdoms, the others being the animals and fungi.  Species Characteristics: Morphologically similar members capable of inbreeding.  Binomial Nomenclature: Species names in the form of Genus (wider taxonomic group) and Species.  Proper Reporting: Plant species must be reported in a taxonomically correct manner.  Online Resources: Utilize online resources like 'Medicinal Plant Name Service' and 'The Plant List'.  Hierarchical Arrangement: Species grouped into clusters of varying similarity.  Hierarchy Formation: Main classification includes divisions.  Plant Kingdom Divisions: Major plant groups - Algae, Mosses, Ferns, Seed-bearing plants.  Pharmaceutical Relevance: Algae, mosses, and ferns briefly discussed due to limited pharmaceutical importance.  Taxonomy Fundamentals: Essential basis for pharmacognostical work.  Correct Identification: Ensures the accurate identification of botanical drugs.  Foundation for Research: Basis for further pharmacological, phytochemical, analytical, and clinical studies.  Pharmacognosy Significance: Key to understanding species' relationships and their impact on medicinal plant research. MORPHOLOGY AND ANATOMY OF HIGHER PLANTS (SPERMATOPHYTA) FLOWER:  Flower's Role: Essential reproductive organ of a plant.  Attractiveness: Often showy to attract pollinators.  Key Characteristics: Size, color, and morphological features.  Morphological Characteristics: Form, fusion, and count of floral parts.  Schematic line drawing of a flower. Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 31.  Calyx: Protective cover during budding, may drop off (e.g. Chelidonium majus L.).  Corolla: Attracts pollinators, varies in number, size, and fusion, but color is not a reliable identifier.  Androecium: Comprises stamens producing pollen, significant for identification.  Gynaecium: Contains individual carpels that develop into the fruit.  Pistil: Composed of stigma, style, and gynaecium, with variations in size and form.  Gynaecium Position: Epigynous or hypogynous in relation to the ovary. Inflorescences  Inflorescences are the arrangements in which flowers are grouped together on a plant.  They provide a valuable feature for recognizing plants, especially medicinal ones.  However, exploring inflorescences is beyond the scope of this introductory presentation. Drugs  Flowers are of great botanical importance but represent a minor source of drugs in phytotherapy and pharmacy.  Chamomile (Matricaria recutita L.): A significant example, known as "Matricariae flos," is used in various herbal remedies.  Other Examples:  Calendula (Calendula officinalis L.): Utilized for its medicinal properties as "Calendulae flos."  Arnica (Arnica montana L.): Valued for its therapeutic benefits, often referred to as "Arnicae flos."  Hops (Humulus lupulus L.): Employed in certain herbal preparations under the name "Humuli flos."  FRUIT AND SEED Seed Development Evolution:  Seeds emerged relatively late in plant evolution. Lower plants, such as algae, mosses, and ferns, do not produce seeds.  The first group to produce seeds were gymnosperms, like the maiden hair tree (Ginkgo biloba L.), which preceded the evolution of angiosperms or fruit-bearing plants.  Simplified schematic representation of (A) a gymnosperm seed sitting on a scale (as in a fir tree) and (B) an angiosperm fruit, covered by both the testa and the pericarp. Michael Heinrich, Fundamentals of Pharmacognosy and Phytochemistry (Elsevier, 2018), p. 32. Gymnosperms:  Gymnosperms produce seeds without a secondary protective layer; the seed is protected only by the testa – the seed's outer layer.  Angiosperms: In angiosperms, the ovule and seed are enclosed within a specialized organ, the carpels, which subsequently develops into the pericarp (the outer layer of the fruit). Pericarps can be hard (nuts), soft (berries like dates and tomatoes), or a combination of both (drupes, e.g., cherry, olives).  Medicinal Use: Medicinal drugs derived from fruits are typically obtained from angiosperm species, given the presence of pericarps.  Fruit Morphology: The morphology of a fruit is crucial for identifying plant species or medicinal drugs.  Classification of Fruits: Fruits can be classified based on the number of carpels and gynaecia (female reproductive structures) per fruit, which can be:  Simple: Developed from a single carpel.  Aggregate: Several carpels from one gynaecium are united in one fruit (e.g., raspberries and strawberries).  Multiple: Gynaecia from more than one flower form the fruit. Drugs Fruit-Derived Products:  Caraway (Carum carvi L.): Known as "Carvi fructus."  Fennel (Foeniculum vulgare Miller): Referred to as "Foeniculi fructus."  Saw Palmetto (Serenoa repens): Also recognized as "Sabal fructus."  Schizandra/Schisandra (Schisandra chinensis Baillon): Available as "Schisandrae fructus." Seed-Derived Products:  (White) Mustard (Sinapis alba L.): Utilized as "Sinapi semen."  Horse Chestnut Seeds (Aesculus hippocastanum L.): Known as "Hippocastani semen."  Ispaghula (Plantago ovata Forssk.) and Psyllium (Plantago afra L.): Derived from "Plantago ovatae semen" and "Psylli semen," respectively.  LEAVES  Leaves: Originate from the stem and play a crucial role in the plant's life.  Primary Function: The key function of leaves is to facilitate the assimilation of glucose and starch. This process, known as photosynthesis, involves utilizing water and carbon dioxide and harnessing energy from sunlight.  Photosynthesis: The vital metabolic process where leaves convert sunlight energy into chemical energy, producing glucose and starch, which are essential for the plant's growth and energy storage. The net photosynthetic reaction is:  6CO2 + 6H2O + light energy → C6H12O6 (glucose) + 6O2  Photosynthesis: This process is not just vital for the survival of all plants; it's the cornerstone of life on Earth.  Energy Production: Photosynthesis provides the energy required for the plant's growth and sustenance.  Basic Building Blocks: Moreover, photosynthesis yields the basic building blocks like glucose, which serve as precursors for complex compounds.  Secondary Metabolites: These basic building blocks play a crucial role in the synthesis of secondary metabolites, which are compounds used in the production of pharmaceuticals.  Pharmaceuticals: Secondary metabolites derived from plants are instrumental in creating a wide array of medicinal drugs. 1. Function of Leaves  Collectors of the sun's energy and its assimilation.  Typical anatomy includes a petiole (stem) and a lamina (blade).  Petiole may be reduced or missing in some cases. General Leaf Anatomy:  Petiole may be reduced or completely missing.  Lamina is a characteristic feature. 2. Adaptation to Environments  Plants exhibit diverse adaptations to various environments.  Adaptation reflected in anatomical and morphological features of leaves. 3. Example of Adaptation: Xerophytic Leaves  Adaptation to dry conditions. Characteristics:  Conservation of moisture.  Fleshy or thick cuticle.  Example: Oleander (Nerium oleander L.). 1. Leaf Surface: Stomata:  Located on the lower surface of the leaf.  Responsible for gaseous exchange.  Surrounded by specialized cells. Functions:  Uptake of CO₂.  Emission of water vapor.  Release of O₂. 2. Stem Anatomy:  Nodes (or 'Knots'):  Points where leaves and lateral buds attach to the stem.  Internodium:  Intermediate area between nodes. 3. Species Characteristic: Leaf Arrangement:  A key characteristic of a species.  Determines the way leaves are arranged on the stem. 4. Example of Leaf Arrangement:  Emphasize the diversity in leaf arrangement. Types of arrangements of leaves. 1. Leaf Form:  Simple Leaves:  Blades not divided into distinct leaflets.  Single, often deeply lobed blade. Compound Leaves:  Two or more leaflets.  Leaflets may have individual petioles (petiolules). 2. Importance of Leaf Form:  Crucial characteristic in plant identification. 3. Variation in Leaf Shapes: Examples:  Oval, oblong, rounded, linear, lanceolate, ovate, obovate, spatulate, cordate. 4. Leaf Margin: Characteristics:  Entire (smooth), serrate (saw-toothed), dentate (toothed), sinuate (wavy), ciliate (hairy). 5. Base and Apex Characteristics: Distinctive Forms:  Both the base and apex contribute to leaf identification. (A) Characteristic shapes of leaves. (B) Characteristic margins of leaves. Stomata Characteristics:  Microscopic features include the form and number of stomata.  Stomata play a crucial role in gaseous exchange. Inner Leaf Structure:  Microscopic examination reveals the inner structure of leaves.  Understanding this structure is essential for detailed botanical analysis. Specialized Secretory Tissues:  Presence of trichomes (glandular hairs) and covering trichomes or bristles.  These tissues serve various functions and contribute to leaf characteristics. Calcium Oxalate Structures:  The presence of calcium oxalate structures.  These structures exhibit a characteristic refractive pattern under polarized light. Calcium oxalate crystals, main forms: (A) rosette (e.g. Datura stramonium, Solanaceae); (B) sand (e.g. Atropa belladonna, Solanaceae); (C) monoclinic prism (e.g. Hyosyamus niger, Solanaceae); (D) needles (e.g. Iris germanica, Iridaceae); (E) raphides (e.g. Urginea maritima, Hyacinthaceae). Microscopic Identification of Nightshade Family (Solanaceae) Leaves:  Powdered leaves from Solanaceae members used for industrial extraction of alkaloid atropine.  Normal chemical methods may not distinguish them due to similar alkaloid content.  Microscopic examination reveals distinct crystal forms in different species, aiding in identification.  Drugs Common Balm (Melissa officinalis L.) and Deadly Nightshade (Atropa belladonna L.):  Components: Melissae folium (Common Balm) and Belladonnae folium (Deadly Nightshade).  Not used in phytotherapy but employed for alkaloid extraction.  High alkaloid content, especially in solanaceous species. Ginkgo (Ginkgo biloba L.):  Component: Ginkgo folium.  Utilized in drug formulations, not for phytotherapy.  Extracted for specific properties or compounds. Green Tea (Camellia sinensis (L.) Kuntze):  Component: Theae folium.  Widely used in non-phytotherapy drugs.  Extracted for its beneficial compounds. (Red) Bearberry (Arctostaphylos uva-ursi (L.) Spreng.):  Component: Uvae ursi folium.  Used in drug manufacturing, not traditional phytotherapy.  Extraction emphasizes unique properties. SHOOTS (=STEM, LEAVES AND REPRODUCTIVE ORGANS) Herbaceous vs. Woody Plants:  Herbaceous Plants ("Herbs"):  Generally short-lived.  Rapid growth.  Detailed examination needed to distinguish outer and inner stem. Woody Plants (Trees and Shrubs):  Clear distinction between bark and inner wood.  Bark and wood are visibly separate. Function of the Stem:  Provides physical strength for positioning leaves, flowers, and fruit.  Cylindrical organ forming the main axis of a plant. Stem Characteristics:  Herbaceous Species:  Outer and inner stem differentiation requires detailed examination. Woody Species:  Clear distinction between bark and inner wood.  Bark and wood serve distinct functions and are visibly different. Xylem and Phloem Function: Xylem:  Responsible for upward transport of water and inorganic nutrients.  Located in the inner parts of the stem.  Essential part of wood. Phloem:  Responsible for downward transport of assimilates (sugars and polysaccharides).  Typically operates from leaves towards other parts of the plant. Cambium and Stem Growth: Cambium:  Found between wood and bark.  Generates new cells for the development of outer (bark) and inner (wood) parts of a secondary stem.  Crucial for stem growth and differentiation. Fine Structure and Diagnostic Criteria: Bark and Wood:  Fine structure is a vital diagnostic criterion for drug identification.  The bark, as an outer protective layer, often accumulates biologically active substances.  Pharmaceutically important barks may accumulate tannins.  Drugs: stem Stem Material in Medicinal Plants:  Stem material is commonly present in drugs derived from above-ground parts (herbs or herba).  Currently, no stem-derived drug holds significant importance in pharmacology. Underground Organs and Modified Stems: Rhizome of Tormentil:  Example of an underground organ used as a drug.  Represents a modified stem with specific functions such as storage and plant spreading. Potato:  Example of an underground organ used as food.  Modified stem serving functions like storage and plant spreading.  Drugs: bark  Frangula, Frangula alnus Mill. (syn. Rhamnus frangula L.) (Frangulae cortex).  Red cinchona, Cinchona pubescens Vahl (syn.:  Cinchona succirubra Pav. ex Klotzsch), C. calisaya Wedd. (the main cultivated species in southern Asia) and Cinchona spp. (Cinchonae cortex).  Oak, Quercus petraea (Matt.) Liebl. and Qu. robur L. (Quercus cortex).  Willow, Salix alba L. and Salix spp. (Salicis cortex).  Drugs: aerial parts (=stem, leaves plus flowers/fruit)  Ephedra, Ephedra sinica Stapf (Ephedra herba).  Hawthorn, Crataegus monogyna Jacq. and C. laevigata (Poir.) DC. (syn. C. oxycantha) (Crataegi herba or Crataegi folium cum flore).  _x005F_x0007_Passion flower, Passiflora incarnata L. (Passiflora herba).  _x005F_x0007_Wormwood, Artemisia absinthium L. (Absinthii herba); in Africa and Asia, sweet or annual wormwood (Artemisia annua L.) is used in the treatment of malaria. Substitution of Leaves with Aerial Parts:  This is a widespread problem in inexpensive phytopharmaceuticals.  Affects products marketed as 'health food supplements.' Consequences of Adulteration:  Altered Constituents:  Adulterated drugs often contain fewer and/or different active constituents.  Impacts the overall quality and efficacy of the phytopharmaceutical.  Importance of Precision Species and Plant Part Definition:  Emphasizes the necessity to precisely define not only the species but also the specific plant part to be used in pharmaceuticals.  Ensures accurate identification and maintains the therapeutic value of the product.  ROOT Three Key Functions of a Typical Root: 1. Anchorage (Plant Stability):  Function:  Provides anchor in the ground or substrate.  Enables the development and stability of above-ground plant organs.  Importance:  Crucial for maintaining the structural integrity and proper positioning of the plant. 2. Absorption and Conduction (Water and Nutrient Uptake): Function:  Primary organ for the uptake of water and inorganic nutrients.  Responsible for the conduction of absorbed substances.  Importance:  Essential for the plant's hydration and nutrition, supporting overall growth and development. 3. Storage (Surplus Energy Reservoir): Function:  Often serves as a storage organ for surplus energy.  Commonly stores polysaccharides, such as starch and inulin.  Importance:  Acts as a reservoir for energy, facilitating the plant's response to fluctuating environmental conditions and aiding in sustained growth. Root Composition: Outer Layer (Bark and Hypodermis):  Forms the protective outer layer of the root.  Inner Cylinder:  Contains xylem and phloem, facilitating the transport of water, inorganic nutrients, and assimilates. Endodermis: Function:  Inner protective layer separating the outer bark from the inner cylinder.  Importance:  Provides additional protection to the root structure. Transport Systems: Xylem:  Transports water and inorganic nutrients upward.  Phloem:  Transports assimilates (sugars and other organic compounds) within the plant. Root Development: Primary Root:  Found in very young plants.  Develops into a thicker structure during plant growth. Secondary Roots:  Develop as the primary root matures.  Often roots or rootstocks with specialized storage functions.  Commonly used in pharmacy for medicinal purposes. ROOTSTOCK AND SPECIALIZED UNDERGROUND ORGANS Botanical Distinctions: Rhizomes and Tubers:  Morphologically stems, not roots.  Have functions similar to roots but are botanically distinct.  Belong to a separate group of plant organs. Rhizomes and Tubers: Rhizomes:  Typically morphologically stems.  Functionally and botanically distinct from roots.  Part of a separate group of botanical drugs. Tubers:  Generally morphologically stems.  Functionally similar to roots.  Classified separately in botanical terms.  Yield a distinct group of botanical drugs. Underground Bulbs: Morphological Origin:  Derived from parts of the leaves.  Botanically separate from roots.  Represent another group of plant organs.  Rhizome and root (radix) drugs  Underground organs of only a few species have yielded pharmaceutically important drugs. Examples include:  Devil’s claw, Harpagophytum procumbens (Burch.) DC. ex Meisn. (Harpagophyti radix, thickened roots).  Korean ginseng, Panax ginseng C. A. Mey. (Ginseng radix).  Tormentill, Potentilla erecta (L.) Raeusch. (syn. Potentilla tormentilla Stokes, Potentillae radix).  Echinacea, Echinacea angustifolia DC., E. pallida Nuttall and E. purpurea (L.) Moench (Echinacea radix).  Siberian ginseng, Eleutherococcus senticosus Maximimowicz (Eleutherococci radix).  Kava-kava, Macropiper methysticum (G.Forst.) Miq. (better known under its synonym: Piper methysticum G.Forst.; Rhizoma Piperis Methystici –kava-kava rhizome).  Chinese foxglove root, Rehmannia glutinosa (Gaertn.) DC. (Rehmannia radix).  Rhubarb, Rheum palmatum L. and Rh. Officinale Baill., as well as their hybrids (Rhei radix, thickened roots).  Sarsaparilla, Smilax ornata Lem. Smilax regelii Killip & C.V.Morton, and Smilax spp. (Sarsaparillae radix).  DIVERSE AND UNSPECIFIED BOTANICAL DRUGS  Some drugs are derived from the whole plant or from specialized organs (e.g. the bulbs in the case of garlic, Allium sativum L.).  The exudates of Aloe vera (L.) Burm. f. (syn. Aloe barbadensis Mill.) leaves are used as a strong purgative.