ABSTRACT
Abstract Averrhoa bilimbi L. and A. carambola L., Oxalidaceae, are the only two species of the genus Averrhoa L. Their leaves are widely used in folk medicine as an adjuvant in the treatment of diabetes. Some species may contain, for example, calcium oxalate crystals, which may lead to risk in its use when there is predisposition of individuals with reduced renal activity. Therefore, there are still few studies on the content of oxalic acid present in them, highlighting the importance of this investigation. The objective of this work was to conduct a comparative anatomical and histochemical study between the species and determining its content of oxalic acid. Semipermanent histological slides were prepared, following common plant anatomy procedures, for analysis of the leaflets in optical microscopy, polarization and scanning electron microscopy coupled with energy-dispersive X-ray spectrometry. To determine the total, soluble and insoluble oxalate content was used titration with potassium permanganate. The anatomical characterization allowed identifying the characters useful in the differentiation of the species. The histochemistry revealed the location of the metabolites. Chemical microanalyses demonstrated that the crystals are of calcium oxalate. A. carambola presented the highest levels of total oxalate and soluble oxalate. The study assists in the identification and quality control of A. bilimbi and A. carambola and brings new data on its oxalic acid content, which are important, in view of the medicinal use of the species.
ABSTRACT
ABSTRACT Ageratum conyzoides L., belonging to the family Asteraceae, is a tropical plant found in some regions of Africa, Asia and South America. This species is popularly known as billy goat weed, “mentrasto” and “catinga-de-bode” and has a large variety of secondary metabolites and biological activities mentioned in the literature. The objective of this work was to contribute the pharmacobotanical standardization of A. conyzoides. Cross-sections were obtained, by hand, for microscopic characterization of root, stem, petiole and leaf blade; to the leaf blade were still made paradermal and longitudinal sections, scanning electron microscopy analysis and maceration. The analysis showed that secretory structures ducts are evidenced only in the petiole and the leaf blade. The root has parenchymatous medullar region; stem, petiole and leaf blade exhibit striated cuticle. Non-glandular trichomes are present in stem, petiole and leaf blade, while capitate glandular trichomes are present only in the leaf blade and are restricted to the abaxial face. These anatomical features are useful for diagnosis of the species and provide support to their quality control.
ABSTRACT
ABSTRACT Dysphania ambrosioides (L.) Mosyakin & Clemants (syn: Chenopodium ambrosoides L.), Amaranthaceae, popularly known as “mastruz”, is an herb widely used in Brazil as anthelmintic. To contribute to the knowledge about medicinal plants, a microscopic analysis was accomplished to describe the main anatomical characters of root, stem, petiole and leaf blade of D. ambrosioides and histochemical tests were performed on the leaf blade. Cross-sections were obtained, by hand, for microscopic analysis of root, stem, petiole and leaf blade; to the leaf blade were still made paradermal sections, scanning electron microscopy analysis, maceration and histochemical tests. The main characters useful in the identification of the plant were: anomalous secondary thickening in the root and stem; presence of idioblasts containing crystal sand in the root, stem, petiole and leaf blade; in these there are also idioblasts with druses; presence of non-glandular and glandular trichomes in the stem, petiole and leaf blade; stomata on the stem, petiole and leaf blade, identified in these as anomocytic and anisocytic; dorsiventral mesophyll and collateral vascular bundles. Maceration revealed that the vessel elements are helical type. Through the histochemical tests, it was evidenced the presence of lipophilic substances, essential oils, oleoresins, phenolic compounds, starch, lignin and calcium oxalate crystals. This work provides support to the quality control of the species.