Comparative pharmacognosy of two medhya dravyas, Brahmi (Bacopa monnieri Linn.) and Mandukaparni (Centella asiatica Linn.)

Background: Brahmi (Bacopa monnieri) and Mandukaparni (Centella asiatica) are the two important distinct Medhya (Nootropic) drugs mentioned in Indian systems of medicine. Lack of morphological description and attribution of similar properties led towards confusion in identity of these two sources. Pharmacopoeias suggest macro-microscopic characterization and chemical profiling of botanical material forms a pilot step in drug standardization. Hence the detailed macro-microscopic records, along with phytochemical documentation of these two plants were planned in the present investigation. Methodology: Matured, authenticated plants were collected from its natural habitat. Macro-microscopic and preliminary phytochemical studies were carried out. Results: Transverse section of Bacopa monnieri passing through midrib is isobilateral in histology whereas that of Centella asiatica is dorsiventral. Striated cuticle and few layered spongy parenchyma are the features of Centella asiatica. Plenty of air cavities with stomatal opening are specific to Bacopa monnieri. Phytochemical analysis of these two drugs has revealed the presence of alkaloids, saponins, glycosides and tannins. In addition to this Centella asiatica has shown the presence of flavanoids. Conclusion: The macro-microscopic and phytochemical tests can be used to differentiate the botanical source of Brahmi/Mandukaparni.