Medicinal Herbs Overview

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Questions and Answers

What is a medicinal herb composed of?

Tender parts of plant axis, leaves, flowers, and fruits (correct)

Dry leaves and herbs only

Only roots and stems of plants

Seeds and fruits exclusively

Which of the following is a characteristic of the herb Lobelia?

Contains alkaloids (correct)

Grows in aquatic environments

Only used for cosmetic purposes

Contains volatile oil

Which herb is known to contain volatile oil?

Vinca

Cannabis

Ergot

Mentha (correct)

What part of the plant is used from Mentha piperita for medicinal purposes?

Dried leaves and flowering tops Signup and view all the answers

What is the taste characteristic of thyme?

Aromatic and pungent Signup and view all the answers

Which of the following active constituents is found in thymol?

Thymol Signup and view all the answers

What type of stomata is characteristic of Mentha?

Diacytic stomata Signup and view all the answers

Which medicinal use is unique to thyme compared to mentha?

Anthelmintic Signup and view all the answers

Which of the following is NOT a component of the volatile oil from Mentha?

Thymol Signup and view all the answers

Identify the type of hair found in both mentha and thyme.

Non-glandular unicellular hair Signup and view all the answers

What unique function does mentha serve that is not listed for thyme?

Cholagogue Signup and view all the answers

Which component is considered a flavonoid in both plants?

Flavonoids Signup and view all the answers

Which of the following is true about non-glandular hairs in mentha?

They are multicellular and uniseriate. Signup and view all the answers

Which of the following is NOT an external use of decongestants?

Expectorant Signup and view all the answers

What color indicates a positive test for Mentha when using H2SO4 and vanillin?

Orange yellow Signup and view all the answers

Which contraindication is specific to Mentha?

May worsen gall stones Signup and view all the answers

Which of the following is a special chemical test related to Thyme?

Thymol crystals with H2SO4 Signup and view all the answers

What condition may result from high doses of Thymol?

Hematuria Signup and view all the answers

Which of the following is a contraindication for using Thyme?

Interaction with anticoagulants Signup and view all the answers

Which is true regarding the use of pure menthol?

It should never be taken orally. Signup and view all the answers

What substance developed a deep bluish green color when tested with Thymol and HNO3?

Thymol crystals Signup and view all the answers

Study Notes

Medicinal Herbs

A drug derived from the tender parts of plants, including leaves, flowers, and fruits.
Types of medicinal herbs include:
- Parts of aerial shoots (e.g., Cannabis).
- Whole aerial parts (e.g., Lobelia).
- Complete plants, including roots.
- Undifferentiated plant bodies, such as Thallophyta (e.g., Ergot and fucus).

Herbs of Medicinal Importance

Groups based on active constituents:
- Herbs containing alkaloids (e.g., Vinca, Cannabis).
- Herbs containing volatile oils (e.g., Mentha, Thyme).
- Herbs containing resin (e.g., Ergot, Ephedra).

Key Examples of Medicinal Herbs

Mentha
- Family: Labiatae (Lamiaceae).
- Aroma: Characteristic and aromatic.
- Taste: Aromatic with a cold sensation.
- Active constituents:
  - Volatile oil (Menthol, Menthone, Menthyl Acetate).
  - Tannins, flavonoids.
Thyme
- Family: Labiatae (Lamiaceae).
- Aroma: Aromatic and pungent.
- Active constituents:
  - Volatile oil (Thymol, Carvacrol).
  - Tannins, flavonoids, gums, resins.

Microscopical Characteristics

Mentha Powder
- Diacytic stomata.
- Glandular hairs (Labiaceous and Capitate) and non-glandular hair (multicellular).
Thyme Powder
- Non-glandular bent hair.

Medicinal Uses

Mentha
- Gastrointestinal tract benefits: Carminative, digestive, anti-spasmodic, antimicrobial, anti-emetic, and promotes liver/gall bladder function.
- Respiratory benefits: Decongestant.
- External uses: Local anaesthetic, anti-pruritic, anti-parasitic.
Thyme
- Gastrointestinal tract benefits: Carminative, digestive, anti-spasmodic, antimicrobial, and anthelmintic.
- Respiratory benefits: Used for whooping cough, as an expectorant, secretolytic, and disinfectant for inhalations.

Chemical Tests

Mentha
- Positive micro-chemical tests with Sudan III.
- Special test results: Menthol crystals react with H2SO4 and produce color changes.
Thyme
- Special test results: Thymol crystals react with glacial acetic acid and other chemicals to yield notable colors.

Contraindications & Drug Interactions

Mentha
- Contraindications: Not advisable for GERD, infants, gallstones; can be poisonous in pure form; avoid on irritated skin.
Thyme
- Contraindications: High doses of thymol can lead to liver toxicity; concentrated forms are contraindicated in pregnancy.
- Drug interactions: Can interfere with anticoagulants, increasing bleeding risk.

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Description

This quiz explores the various types of medicinal herbs, their classifications based on active constituents, and key examples such as Mentha and Thyme. Test your knowledge on the properties and uses of these important plants in medicine.