Comparative pharmacognostic and phytochemical investigation of two plant species valued as medhya rasayanas.

ABSTRACT

Centella asiatica and Bacopa monnieri widely known as Brahmi are considered as ‘Medhya rasayanas’ in Ayurveda meaning brain tonic. However, these plants are distinctly different. The name Brahmi, Jala-brahmi or water-brahmi is assigned to Bacopa monnieri whereas "mandukaparni", often confused with Brahmi, refers to Centella asiatica. A detailed investigation of whole plant and roots of both the crude drugs was carried out. The diagnostic characteristics includes presence of stomata, vessels with spiral thickening, rosette crystals of calcium oxalate in Centella asiatica and xylem vessels with reticulate thickening, glandular hairs, simple, round and oval starch grains, measuring 4-14 μ in diameter in Bacopa monnieri. Various physicochemical parameters were also established. Phytochemical screening revealed the presence of many therapeutically important classes of phytoconstituents such as glycosides, alkaloids, saponins, protiens and carbohydrates. The present work was undertaken to generate information regarding relevant pharmacognostical, phytochemical and physicochemical data needed for proper identification and authentification of two crude drugs belonging to two different families, mainly focusing and exploring the aspects leading to common effect of improving memory.