Pharmacognosy - Subterranean Organs

Pharmacognosy Lecture Notes: Subterranean Organs

Course: Pharmacognosy (PG202)
Level: Pharm D - Level 1
Semester: Spring 2024-2025
Lecture: 5
Date: 10/3/2025
Professor: Dr. Dina M. Bahgat
Contact: dina.bahgt@pharma.asu.edu.eg, Room 3029, Pharmacognosy Department. Office hours: Sunday 9-11

The lecture focuses on subterranean organs.
Other topics in the course include seeds, fruits, unorganized drugs, marine natural products, and optimum nutrition.

Definition: Plant organs located below the ground.
Function: Primarily storage for food material (carbohydrates, inulin, sugars).

Piliferous layer: Epidermis region with abundant root hairs for water and nutrient uptake.
Cortex: Large, thin-walled parenchyma cells.
Endodermis
Stele: Vascular tissue

Primary root: Develops into a taproot, associated with secondary roots.
Fibrous root: Primary root stops growing; numerous slender roots arise from the stem base.
Adventitious root: Arise from non-root tissue during normal development.

Rhizome:
- Shows nodes and internodes (long or short).
- Grows horizontally below ground.
Stem Tuber:
- Swollen underground stem.
- Full of reserve food material.
- Differs from root tubers by having eyes (buds) and scaly leaves.
Corm:
- Short, swollen, and erect.
- Covered with scaly brownish leaves at the nodes.
- Large apical bud and small axillary buds at each node.
Bulb:
- Reduced to a small flattened disc.
- Crowned with fleshy scaly leaves.
- Adventitious roots arise from the disc.

Epidermis
Cortex
Vascular bundles
Phloem
Xylem
Pith
Procambium
Interfascicular parenchyma
Monocot closed vascular bundle
Dicot. Open Collateral V.B.

Feature	Root	Subterranean Stem
Leaves	Absent	Present, scaly
Buds	Absent	Axillary bud
Lateral appendages	Present, lateral roots	Present
Adventitious roots	Absent	Present
Growing point	Present (root cap or calyptra)	Protected by leaves forming a bud
Nodes & internodes	Absent	Present

Considered based on origin, morphology, key elements, active constituents (A.C.), tests, uses, and contraindications.
Examples:
- Volatile oil plants (ginger, curcuma, garlic, valerian)
- Glycosides
- Alkaloids

Origin: Dried rhizome of Zingiber officinale, Fam. Zingeberaceae, deprived of roots and outer dark tissues.
Morphology: Fingers bearing buds.
Key elements:
- Scitaminaceous starch (eccentric hilum & transverse striations).
- Septate Non lignified fiber except middle lamella.
Active constituents:
- Volatile oil (zingiberene, α-curcumene).
- Non-volatile, pungent, phenolic, oily principle Gingerol (gives pungency) & destroyed by Alkali.
- Starch
- Resin
Chemical tests:
- Test for volatile oil with Sudan III.
- Test for starch with Iodine.
Uses:
1. Spice & condiment.
2. GIT: Carminative, Stomachic, digestive & dyspepsia (stimulates saliva flow, activates peristalsis).
3. Anti-emetic (motion sickness), better than Dramamine. Ginger cookies for pregnant women.
4. Cholagogue.
5. Antimicrobial (gingerol).
6. Antidiabetic, antihyperlipidemic.
7. Expectorant, Relief of sore throat.
8. Antirheumatic.
9. Immunostimulant.
10. Radioprotective
  - Reference: https://doi.org/10.1016/j.jnutbio.2020.108486
Precaution:
- Has a blood-thinning effect.
- Contraindications:
  - Aspirin, warfarin, heparin
  - Gallstones (due to cholagogue effect).
Adulteration:
- Japanese Ginger: Compound starch, different oil properties.
- Substituted Ginger: Capsicum + powder curry + wheat starch.
- Exhausted Ginger

Origin: Dried rhizome of Curcuma domestica, Fam. Zingeberaceae. Also known as Turmeric, Indian Saffron, Yellow root. Steamed & Boiled rhizome
Morphology: Curcuma bulb with longitudinal wrinkles.
Key elements:
- Cork cells
- Gelatinized starch
Active constituents:
- Volatile oil (zingiberene + bisabolene).
- Starch (gelatinized).
- Yellow pigment (Curcuminoids).
- Resin.
Tests:
- Volatile oil: Sudan III.
- Curcuminoids: Conc. H2SO4 + 95% alcohol turns particles red. Ether & CHCl3 extract on filter paper gives yellow color, turns orange-red with boric acid, bluish-black with NH3.
Uses:
1. Aromatic, stomachic; condiment, spice.
2. Treatment of jaundice & hepatitis (Hepatoprotective).
3. Cholagogue.
4. Natural coloring agent.
5. Turmeric paper (test for boric acid).
6. Anticancer
7. Decrease cholesterol, LDL and increase HDL
  Nano-delivery systems
  Liposomes
  Micelles
  Goldnanoparticles
  Improvedbioavailability
  Polymernanoparticles
  Improvedstability
  Exosomes
  Improvedsolubility
  Solid lipidsnanoparticles
  Nanocrystals

Origin: Fleshly or carefully dried bulbs of Allium sativum, Family Liliaceae
Active constituent
1. Volatile oil (17 sulphur compounds e.g. alliin).
2. Vitamins & minerals.
3. Glutathione
  Alliin (unstable) Allicin Antibacterial Allinase enzyme
Uses:
- Powerful antibacterial, antiviral & antiseptic.
- Powerful expectorant & respiratory disinfectant
- Improves dementia (Alzheimer)
- Hypotensive, Reduce LDL, Reduce platelet aggregation (antithrombotic).
- Hypoglycemic (Antidiabetic)
- Immuno-stimulant.
- Anticancer.
- Hepatoprotective
- Anti-inflammatory in Arthritis, Alopecia
- Cardiovascular disorders
Contraindications:
- Sensitive stomach (heartburn).
- Patients taking anti-thrombotic agents (e.g., aspirin).
- People allergic to garlic.

Origin: Dried rhizome & roots of Valeriana officinalis, Family Valerianaceae, collected in autumn.
Active constituents:
1. Volatile oil (bornyl isovalerianate).
  Iso-valerianic acid, Oily liquid with unpleasant odor Bornyl isovalerianate Enzyme
2. Epoxy iridoid esters (valepotriates)
Uses:
1. Sedative (tranquilizer) in hysteria (valepotriates + minimum amount of V.O.).
2. Carminative.
3. Antispasmodic.