Step 1: Understanding the Concept:
\textit{Gymnema sylvestre} (Gurmar) is a traditional Ayurvedic herb used for managing diabetes. Its name "Gurmar" literally means "sugar destroyer."
Step 2: Detailed Explanation:
1. Gymnemic Acids: The active constituents are a group of triterpenoid saponins called gymnemic acids.
2. Suppression of Taste: When the leaves are chewed, they temporarily paralyze the sweet taste receptors on the tongue, making sugar taste like sand.
3. Pancreatic Effect: Studies suggest that Gymnema extract can increase the regeneration/repair of pancreatic \(\beta\)-cells and stimulate insulin secretion, thus lowering blood glucose levels.
Step 3: Final Answer:
Gymnema is unique in its dual action: reducing the craving for sugar by blocking taste and physically improving the insulin-producing capacity of the pancreas.