Pharmacognostic Investigation of the Leaves and Stems of Viburnum erubescens Wall.ex DC
Purpose: Some pharmacognostical investigations were carried out on the leaves and stems of Viburnum erubescens Wall.ex DC to record parameters for identifying and differentiating various species of Viburnum.
Methods: The research specimens were authenticated and preserved both in fresh and dry forms. The leaves and stems were morphologically screened followed by anatomical studies with the aid of Labphot 2 microscopic units. Powder microscopy and micrometric studies, including leaf constants, were performed using suitable tools and reagents under different magnifications. Physicochemical parameters such as alcohol and aqueous extractive values, ash values, crude fibre content for stem, and fluorescence properties were also determined. The specimens were subjected to successive extraction processes by Soxhlet method using solvents of increasing polarity. Qualitative chemical screening tests with suitable reagents were also undertaken. Results: The leaves were petiolate and opposite, acuminate apex with unequal base, abaxial surfaces which turned blackish on storage, and had irritant smell with a slightly bitter taste. The vein islets were squarish and polygonal. Trichomes and club-shaped glandular trichomes were evident. The barks were
hard and brittle with abundant fissures. The periderm was four-layered followed by homogenous parenchyma. The phloem region appeared with sclerenchyma elements; libriform fibres and tanniferous cells were also evident. The presence of phytosterols, triterpenoids, glycosides (saponins) and phenolic compounds (flavonoids and procyanidins) was positive for both the leaf and the stem. Conclusion: The findings of this study could be useful in identifying Viburnum species, both in whole and powder form. Also, the parameters derived from this study may be useful in differentiating this species from the rest of its relatives.
Keywords: Pharmacognostic investigation; Amoeboid; Caprifoliaceae; Libriform; Stone cells; Viburnum erubescens