RESUMEN
Scutellaria agrestis A. St. -Hil. ex Benth. , Lamiaceae (trevo-roxo) is cultivated for medicinal purposes by residents of the riverine communities in the State of Amazonas, Brazil. This study aimed to characterize the anatomy and to make histochemical analysis on vegetative organs of S. agrestis. Samples of the leaf, stem and root were collected from five plants cultivated by the communities located in the Solimões river, Amazon. These samples were fixed and prepared following standard techniques for scanning electron microscopy and for light microscopy. Histochemical tests were carried out on sections to detect the main classes of compounds present in the secretion. Numerous glandular trichomes are seen in both leaf and stem of S. agrestis. The leaves are amphi-hypostomatics and show dorsiventral mesophyll. Hydathodes are present at the tip of the marginal teeth. Anthocyanin pigments occur into the epidermal cells of the stem, petiole, and abaxial leaf surface. The petiole is concave-convex shaped and bears collateral vascular bundles. The stem showed square-shaped, evident endoderm, collateral vascular bundles and parenchymatous pith. The root displays a typical protostelic structure. Idioblasts containing mucilage and phenolic compounds occur in the cortex. These data are important, as they can be useful to identify this species, contributing to the quality control of the medicinal plant.
RESUMEN
The purpose of this paper was to carry out an anatomical and histochemical analysis of the vegetative organs of Cissus verticillata (L.) Nicolson & C.E. Jarvis, Vitaceae, to contribute for the attest the taxonomic identity of the medicinal plant. Samples from root, stem, leaf and tendril were cleared, dissociated and processed according to the usual methodology for observation under light and scanning electron microscopes. Histochemical tests were performed in order to identify polysaccharides, phenolic and lipid compounds. The C. verticillata root is typically protostelic, and the stem is eustelic with collateral bundles. The tendril presents structural organization similar to the stem, suggesting a common origin for both. The petiole has an epidermis with ornamented cuticle; the cortex is composed of collenchyma and parenchyma, and the vascular tissues are arranged in collateral bundles. The leaf blade is amphistomatic with non-glandular and glandular trichomes, and the mesophyll is dorsiventral. The identification of the idioblasts as secretion site of the phenolic compounds, mucilage and terpenoids as being responsible for the potential activity of the plant is of fundamental importance for future bioprospecting research on this species.
RESUMEN
Anatomical and histochemical investigations of Sphagneticola trilobata (L.) Pruski, Asteraceae, secretory structures in leaves and stems and the seasonal variation of essential oils were carried out. Histochemical techniques enabled the specific location of the essential oil accumulation in the internal (canals) and external structures (trichomes). Histochemical analysis showed that the secretory trichomes produced steroids. The highest yield was obtained from plants collected in winter, when it was registered low temperature and precipitation. The essential oil was characterized by high percentage of hydrocarbon sesquiterpenes, hydrocarbon monoterpenes and low levels of oxygenated sesquiterpenes. The major components were germacrene D (11.9-35.8%), α-phellandrene (1.4-28.5%), α-pinene (7.3-23.8%), E-caryophyllene (4.6-19.0%), bicyclogermacrene (6.0-17.0%), limonene (1.8-15.1%) and α-humulene (4.0-11.6%). The percentage of most of the individual constituents present in S. trilobata essential oil changed significantly during the months.