Rauwolfia and vasaka

1. Biological Source:

Rauwolfia is derived from the dried roots of Rauwolfia serpentina Benth., belonging to the family Apocynaceae. It is commonly known as Indian snakeroot or Sarpagandha.

2. Chemical Nature:

The primary chemical constituents of Rauwolfia are alkaloids, particularly reserpine, ajmaline, serpentine, and ajmalicine. These alkaloids have strong pharmacological activities, especially on the nervous and cardiovascular systems.

3. Identification Tests:

• Dragendorff’s Test: Extract Rauwolfia with alcohol and add Dragendorff's reagent (potassium bismuth iodide). A reddish-brown precipitate confirms the presence of alkaloids.
• Reserpine Test: Treat the extract with acetic anhydride and sulfuric acid. A violet color indicates the presence of reserpine.
• Thin Layer Chromatography (TLC): Separate the alkaloids using appropriate solvents. Visualization under UV light or iodine vapors helps in identifying the individual alkaloids.

4. Uses:

• Antihypertensive: The alkaloid reserpine is used to treat high blood pressure by depleting norepinephrine in the nerve endings, leading to vasodilation.
• Sedative and Tranquilizer: Reserpine has a calming effect and has been used to treat anxiety and mental disorders such as schizophrenia.
• Antipsychotic: Rauwolfia extracts were historically used in traditional medicine for mental disorders.
• Snakebite treatment: In traditional medicine, it is used as an antidote for snake bites.

Vasaka (Adhatoda)

1. Biological Source:

Vasaka is obtained from the leaves, roots, and flowers of Adhatoda vasica Nees, belonging to the family Acanthaceae. It is commonly known as Malabar nut or Adulsa.

2. Chemical Nature:

The chief active constituents of Vasaka are alkaloids, mainly vasicine and vasicinone. These are quinazoline alkaloids with strong bronchodilatory and expectorant properties.

3. Identification Tests:

• Murexide Test: When an extract of Vasaka is treated with hydrochloric acid and potassium chlorate, and ammonia is added, a pink color indicates the presence of vasicine.
• Dragendorff’s Test: As in Rauwolfia, this test confirms the presence of alkaloids by producing a reddish-brown precipitate.
• UV-Vis Spectroscopy: Vasicine and related alkaloids exhibit characteristic absorbance at specific wavelengths under UV light.

4. Uses:

• Expectorant and Bronchodilator: Vasaka is used to treat respiratory disorders like asthma, bronchitis, and cough by promoting the expulsion of mucus from the airways.
• Antitussive: The leaves and extracts are used in cough syrups due to their soothing action on the respiratory tract.
• Anti-inflammatory: It possesses anti-inflammatory properties that make it useful in managing respiratory infections.
• Antioxidant: Vasaka has shown antioxidant activity, contributing to its protective role in various diseases.
• Traditional uses: In Ayurveda, it is used to treat tuberculosis, bleeding disorders, and skin ailments.