Pharmacognostic Study of Dioscorea villosa Leaves

Abstract

Context: Yam (Dioscorea spp.) is an important edible tuber plant used for medicinal purposes to promote health and longevity in Chinese tradition. Steroidal saponins were reported to be the major physiologically active constituents in yams. Therefore, this study was designed to investigate its pharmacognostic characters for its standardization. Materials and Methods: Macroscopic, microscopic, and physiochemical evaluation of Dioscorea villosa was performed using standardized procedures as mentioned in the WHO guidelines. Thin-layer chromatography (TLC) was done to check the purity and identification of the drug. Results and Discussion: Morphology of D. villosa showed that the upper surface of leaves was green in color, having bitter taste and some characteristic odor. The presence of calcium oxalate crystal, thin long fibers, xylem vessels, and epidermal cells was observed in powder microscopy. Phytochemical analysis of crude extracts indicated the presence of alkaloids, glycosides, saponins, and flavonoids. The presence of saponins was also confirmed by foaming index. TLC was done for all the extracts which showed a number of spots indicating the presence of number of chemical constituents.Conclusion: All the above pharmacognostic parameters could be useful for the authentication and preparation of monograph for D. villosa.