Anatomy, histochemistry and phytochemical profile of leaf and stem bark of Bathysa cuspidata (Rubiaceae)

Abstract

Bathysa cuspidata (A. St. Hil.) Hook. f. ex K. Schum. is a species native to the Atlantic Rainforest of Brazil, with stem bark currently used in folk medicine. Uncontrolled bark collections cause problems of environmental sustainability, making it necessary to evaluate more abundant and renewable new sources of raw plant material, such as leaves. This work evaluated the anatomy, histochemistry and phytochemistry of leaves and stem bark of B. cuspidata, aiming to find similarities in the chemical composition between these plant parts and to provide anatomical data to supplement the quality control of this plant drug. Common light and scanning electron microscopy techniques were used in the anatomical and histochemical studies. Thin-layer chromatography and high-performance liquid chromatography were used for the phytochemistry analysis. The concentration of total phenolics was determined using the Folin–Ciocalteau method and the contents of proanthocyanidins using the vanillin reagent. The leaves and bark of B. cuspidata display morphoanatomical characters common to the family Rubiaceae. The histochemical and phytochemical results reveal similarities and differences between the leaves and bark of B. cuspidata, suggesting that the extracts of both parts should be considered and subjected to pharmacological studies in order to investigate the effectiveness of the therapeutic actions reported in folk medicine.