Microstructural and Histochemical Study of the Medicinal Plant Ephedra przewalskii Stapf

Abstract

Background: Ephedra przewalskii Stapf. is a perennial shrubby plant of the family Ephedraceae, naturally distributed in the dry and cold desert regions of Mongolia. In traditional medicine, the stems and roots of this plant have been used as decoctions for the treatment of gastrointestinal spasms, abdominal distension, urinary retention, and general fatigue. Members of the Ephedraceae family are known to contain sympathomimetic alkaloids such as ephedrine and pseudoephedrine, which exert strong physiological effects on the central nervous system, respiratory tract, and cardiovascular system. However, detailed information on the tissueand cell-level localization of biologically active compounds and the microstructural characteristics of E. przewalskii remains limited. Aim: This study aimed to investigate the microanatomical structure and histochemical characteristics of the stem and root of Ephedra przewalskii Stapf., with particular emphasis on the localization of biologically active compounds. Materials and Methods: Plant samples were collected in July from Chandmani soum, Govi-Altai province, Mongolia. The collected material was air-dried in the shade and softened using Ostrich and Fleming solution prior to sectioning. Transverse sections of the stem and root were prepared using a hand microtome and examined under an Olympus light microscope. Histochemical analyses were performed using standard reagents to detect alkaloids, phenolic compounds, tannins, essential oils, polysaccharides, and starch. Results: The stem epidermis consisted of thin-walled, quadrangular cells with a surface covered by spherical protuberances. The stomatal apparatus exhibited a tetracytic structure, and photosynthetic activity was primarily localized in the stem chlorenchyma. The vascular bundles were collateral, with phloem located externally and xylem internally. Idioblasts containing reddish-brown crystalline inclusions were observed in the central pith of the stem. The root showed a polyarch central cylinder, with uniformly distributed, rounded parenchymal cells, and idioblasts similar to those observed in the stem. Histochemical analysis revealed the presence of flavonoids, alkaloids, polysaccharides, and tannins in the stem, predominantly localized in parenchymal and chlorenchymal tissues. In the root, polysaccharides, tannins, and starch were detected, whereas alkaloid accumulation was more prominent in the stem parenchyma. Conclusion: The microscopic examination of Ephedra przewalskii Stapf. revealed the characteristic structures of the stem epidermis, stomata, chlorenchyma, vascular tissues, and crystal-containing idioblasts, as well as a polyarch central cylinder in the root. Histochemical reactions detected flavonoids, alkaloids, tannins, starch, and polysaccharides in the stem, whereas tannins, starch, and polysaccharides were identified in the root. These findings provide a comprehensive characterization of the anatomical and chemical features of the different plant organs.