Basis Of Herbs Action

Rasa: Of those described in Ayurveda, rasa is based on taste. Different types of taste of herbal drugs induce different physiological activities in the body depending on their constituents. The types are as follows -

• Amla (Sour): Sialogouge, Appetiser and digestive.
• Kashaya (Astringent): Heals wounds, diuretic, causes stiffness and soreness of throat and dryness in mouth.
• Katu (Pungent): Sialogouge, Appetiser, lacrimatory, produces tingling sensation of tongue and useful in dyspepsia.
• Lavan (Salty): Readily soluble, water retaining, softening, appetizer, digestive, sialogogue, expectorant and diuretic.
• Madhura (Sweet): Pleasant, brain and heart tonic and galactogogue.
• Tikta (Bitter): Appetiser and produces dryness in mouth.

Relationship between Rasa and Tridosha

Vipaka: Metabolism of the products arising out of the biochemical changes of food and drugs during the gastrointestinal digestion.  

Difference in action between Rasa and Vipaka

Veerya: Potency of a drug (therapeutic efficacy).

• Sheetaveerya: Potency which diminishes secretions, stabilises excretory functions, stops haemorrhage and increases vigour and vitality, aggravates Vata and Kapha and subdues pitta.
• Ushnaveerya: Potency leading to storing up of energy, easy digestion, diaphoresis, emesis, thirst and fatigue, subdues Vata and Kapha but excites Pitta.
• Prabhava: Refers to specific and characteristic influence of a drug that cannot be explained otherwise.