Characterization of Pharmacognostical and Preliminary Phytochemical Features of Tubers of Dioscorea oppositifolica L.

Introduction: Ayurveda opines that the plants which are grown in one’s own vicinity should be used for food and medicinal needs, though beneficial either as food or as medicine there are many less explored plants. Rare knowledge on folklore plants is passed on from generations to generations traditionally. One such plant is Dioscorea oppositifolia L. (Dioscoreaceae) found frequently in and around Udupi locally known as Kaadu genasu. The plant is large climber with numerous cylindrical tubers which are consumed as food as it is very nutritive and used as food during famine. On account of these utilities of this less explored plant material, a detailed pharmacognostical study including macro and microscopy was conducted. Methods: Tubers of D. oppositifolia L. was subjected to organoleptic, macro microscopic, physicochemical, HPTLC , nutritional values assessment, characterization employing standard methodology mentioned in pharmacopoeia and other herbal analysis protocols. Results: The matured tubers of D. oppositifolia L. is on an average 25 cm in length 3 to 4 cm in diameter; cylindrically elongated; outer surface is off white with lot of rootlets and cut inner surface is white and mucilaginous. TS of tuber consists of 3 to 5 layers of thin-walled cork cells, followed by cortex formed from thin-walled parenchyma having lot of starch grains; ground tissue consists of parenchyma cells consisting of cells with contents, starch grains and acicular crystals; endodermis layer which is distinct is present following cortex; groups of scattered vascular bindles, comprising of vessels with crown of phloem patches occur towards the inner regions.  Preliminary phytochemical study revealed the presence of alkaloids, steroids, carbohydrates and saponins. HPTLC photo documentation showed. No spot under short UV, 4 bands under long UV and 5 bands under white light after derivatisation with vanillin sulphuric acid reagent.  Conclusion: Results of this study can be utilized for identification of the drug as well as systematic document on purity standards of this extra pharmacopoeial drug.