Pharmacognostical standardization of roots of Imperata cylindrica Linn (Poaceae)

Imperata cylindrica Linn. Beauv (Poaceae), commonly known as Darbh in Hindi, is an important drug of “Trinpanchmool” and used extensively for the treatment of various ailments viz. urinary calculi, retention of urine, diabetes, cardiac disorder, gout, common cough and cold, inflammation, anemia, as aphrodisiac, etc. The present study was aimed to undertake pharmacognostical studies to fulfill the work required for the identification of the drug. The macroscopic studies revealed that the roots are fibrous, arising from nodes of stolons having uneven surface with fine wrinkles, light brown to dark brown in colour, fibrous fracture, taste and odour indistinct. Microscopically the epidermal cells are thin walled, semi circular with projection on outer walls. The cortex is differentiated into outer thin continuous cylinder of subepidermal sclerenchymatou cells. Inner cortex consists of several radially elongated wide air chambers and thin uniseriate partition filaments comprising of spherical cells. The stele has an outer covering of endodermal layer of tabular cells and depositional silica bodies. The entire pith tissue of the stele consists of sclerenchymatous cells. The metaxylem vessels are circular and thin walled, but protoxylem are not well developed. In between the metaxylem elements occur two small crystals of phloem. Moisture content, total ash, acid insoluble ash, alcohol soluble extractive, water soluble extractive were 7.3, 8.3, 5.77, 4.8 and 5.6% respectively. Thin layer chromatography (TLC) of alcoholic, chloroform and aqueous extracts showed 5, 3 and 2 spots respectively. All there diagnostic features may be useful for proper identification of the crude drug.