Pharmacognosy 2 Lecture 6: Fruits

Course Information

• Academic Year: 2024/2025
• Course: Pharmacognosy 2
• Course Code: PG203
• Lecture Number: 6
• Topic: Fruits

Lecture Aims

• Provide a comprehensive understanding of the structure, identification, and pharmacognostic importance of medicinal fruits.
• Provide a fundamental understanding of fruit structure and classification in pharmacognosy.
• Describe the macroscopic and microscopic features of fruits to differentiate between various types.
• Classify fruits based on their development from different floral structures (true fruits, false fruits, composite fruits).

Lecture Competencies

• Understand the basic structure of fruits (epicarp, mesocarp, endocarp) and their functions in fruit anatomy.
• Recognize key macroscopic characteristics of fruits (shape, color, surface, scars).
• Classify fruits into types (simple, aggregate, composite).
• Differentiate between true fruits (derived from gynoecium) and false fruits (involving other floral parts).

Lecture Contents

• Non-umbelliferous fruits:
  • Capsicum Fruit
  • Nigella
  • Coffee beans (Calabar beans)
• Introduction to fruits

Capsicum Fruit

• Name: Capsici Fructus, Chillies, Cayenne Pepper
• Origin: Dried ripe fruits of Capsicum minimum (Solanaceae)
• Geographical Source: Southern India and South America, primarily Africa.

Capsaicinoids

• Pungent principles (oil soluble): Capsaicin, 6,7-dihydrocapsaicin, nordihydrocapsaicin
• Pungency is destroyed by oxidation (KMnO4 or K2Cr2O7).
• Pungency is not destroyed by alkalis.
• Gingerol is a pungent principle of Ginger destroyed by alkalis.

Other Components of Capsicum Fruit

• Carotenoid pigments (antioxidant).
• Steroid glycosides (capsicosides A, B, C, D).
• Fixed oils and trace of volatile oil.
• Fats, proteins, and vitamins A & C.

Uses (Capsicum Fruit)

• External: Stimulant, counter-irritant, rubefacient; used in ointments, plasters, and medicated wool to relieve rheumatism and lumbago.
• Internal: Condiment and spicy flavouring.

Mechanism of Action (Capsaicin)

• Burning and painful sensations result from chemical interaction with sensory neurons.
• Capsaicin (vanilloid family member) binds to vanilloid receptor subtype 1 (TRPV-1), a pain and heat receptor.

Treatment of Capsaicin Exposure

• Ingestion: Cold milk is effective in relieving burning sensation due to the detergent effect of casein (milk protein) on capsaicin.

Internal Uses (Capsicum)

• Atonic dyspepsia (indigestion and flatulence).
• Increased metabolism of fats, reducing appetite and treating obesity.
• Used in children for thumb-sucking and nail biting.

External Uses (other)

• Form: Ointments and plasters.
• Cases: Rheumatism, lumbago, and after Herpes zoster infections (postherpetic neuralgia).
• Action: Pain controller and counter-irritant activity.
• MOA of capsaicinoids: Depletion of substance P (neurotransmitter); reduced cutaneous hypersensitivity, pain relief through binding to vanilloid receptor subtype 1 (TRPV1)

Contraindications (External)

• Application on injured skin.
• Allergy to capsicum content (first application to a small area of skin).

Contraindications (Internal)

• People with ulcers, heartburn, or gastritis.

Side Effects

• Burning of the mouth and throat, runny nose (internal use).

Chemical Tests (Capsaicin)

• Capsaicin + FeCl3: Bluish-green color
• Capsaicin + H2SO4 + sucrose: Violet color after a few hours

Senna Pods

• Name: Senna Fruit, Senna Fructus, also as Senna Legumes
• Origin: Dried ripe fruits of Cassia acutifolia (Alexandrian senna pods) & Cassia angustifolia (Tinnevelly Senna Pods) (Leguminosae)
• Other characteristics: Non-glandular trichome
• Endocarp fiber + Ca oxalate prisms (Crystal Sheath)

Active Constituents (Senna Pods)

• Hydroxyanthracene glycosides (Sennosides A-D) are located primarily in the pericarp.
• Flavonoids (specifically derivatives of kaempferol and isorhamnetin)
• Mucilage (galactose, galacturonic acid, and arabinose)
• Sugars (glucose, fructose, and sucrose)

Action and Uses (Senna Pods)

• Treat short-term constipation (acute cases such as anal fissures, hemorrhoids, after recto-anal operations, bowel clearance before X-ray or abdominal surgery).

Mechanism of Action (Senna Pods)

• Sennosides are not absorbed in the upper gut but are converted by the large intestinal microflora into aglycones (mainly rhein anthrone), stimulating laxative effects on the colon.

Contra-indications (Senna Pods)

• Long-term constipation treatment.
• Chronic use or abuse can lead to electrolyte imbalance (K deficiency), disorders of heart function and muscular weakness.
• Avoid use with cardiac glycosides and diuretics (due to electrolyte disturbance).
• Intestinal obstruction, abdominal pain, acute intestinal inflammation (colitis, appendicitis).
• Children under 12 years old
• Pregnancy and lactation (due to possible side effects)

Other (Senna Pods)

• Side effects; Cramps and discomfort in the gastrointestinal tract may lead to dose reduction or addition with fennel or anise supplements.
• Possible liver and kidney effects from chronic use.

Other Topics

• Vanilla Pod
• Star Anise
• Black Pepper
• Hawthorn Berry

(Specific information about each topic will be added as data becomes available from provided text).