Phytochemical and morpho-anatomical study of the vegetative organs of Psychotria fractistipula L. B.Sm., R.M. Klein & Delprete (Rubiaceae)

Psychotria fractistipula L.B.Sm, R.M. Klein & Delprete (Rubiaceae) is found in the existing Atlantic Forest in the South of Brazil, in the Paraná and Santa Catarina States. The members of Rubiaceae are characterized chemically by the presence of alkaloids, some pharmacological properties of which include antifungal, antibacterial, analgesic, antioxidant, antimutagenic, and antiviral activities. In this study, we report the results of anatomical, morphological, and histochemical analyses of the leaves and stems of the Rubiaceae family member, P. fractistipula. The anatomical analysis involved of light microscopy and scanning electron microscopy. Morpho-anatomical and histochemical characterization were made using standard methodology. The isolated compounds were identified by Nuclear Magnetic Resonance spectroscopic analysis. The following structures are highlighted as the distinctive features of the species: presence of petiolate leaves and a petiole base, leaf blade with smooth cuticle on both surfaces, paracytic stomata, and, dorsiventral mesophyll and presence of trichomes on the leaves and stems. Phytosteroids, identified as β-sitosterol and campesterol, were observed in the hexane fraction of the stem. Future studies should focus on the isolation of other fractions of interest and their characterization through specific biological and cytotoxicity assays.

Botanical quality control of digestive tisanes commercialized in an urban area (Bahía Blanca, Argentina)

ABSTRACT Digestive herbal teas in the form of monoherbal infusions or in mixtures are the most commonly used form of phytotherapy in Bahía Blanca (Argentina). This practice is based on family tradition reinforced by current trends reverting to the ingestion of natural products. The objective of this work was to analyze the botanical quality of the digestive mixtures sold in Bahía Blanca as fine cut mixtures (in tea bags) and thick cut mixtures (fragmented herbs). Samples of seven mixtures sold in the form of tea bags and four as bags of fragmented herbs were studied under stereoscopic and optical microscopes and micrographic studies were carried out following conventional protocols. Observed characteristics were compared with those in the reference bibliography for verified genuine monoherbs. In the studied products a total of 21 different species were found. There was total concordance between the species declared on the label and those identified in the samples in six of the mixtures in the form of tea bags and in only one of the bags of fragmented herbs. Adulterations were found in four of the samples analyzed (one in a tea bag and three in the fragmented mixtures). The labels on only two of the tea bag samples presented complete and correct information; in the remaining samples irregularities were found related to: the taxonomic identification of the species, the absence of a lot number, date of expiry, the plant parts used and proportions of the herbs etc. The findings underline the great importance of quality controls as a tool to protect the rights of phytotherapy consumers.

Morpho-anatomical study of Stevia rebaudiana roots grown in vitro and in vivo

ABSTRACT Stevia rebaudiana (Bertoni) Bertoni, Asteraceae, is used as a food additive because its leaves are a source of steviol glycosides. There are examples of tissue culture based on micropropagation and phytochemical production of S. rebaudiana leaves but there are few studies on adventitious root culture of S. rebaudiana. More than 90% of the plants used in industry are harvested indiscriminately. In order to overcome this situation, the development of methodologies that employ biotechnology, such as root culture, provides suitable alternatives for the sustainable use of plants. The aim of this study was to compare morpho-anatomical transverse sections of S. rebaudiana roots grown in vitro and in vivo. The in vitro system used to maintain root cultures consisted of a gyratory shaker under dark and light conditions and a roller bottle system. Transverse sections of S. rebaudiana roots grown in vitro were structurally and morphologically different when compared to the control plant; roots artificially maintained in culture media can have their development affected by the degree of media aeration, sugar concentration, and light. GC–MS and TLC confirmed that S. rebaudiana roots grown in vitro have the ability to produce metabolites, which can be similar to those produced by wild plants.

Morpho-anatomical analysis of Aspidosperma olivaceum and A. polyneuron, Apocynaceae

The family Apocynaceae includes many medicinal species, such as Aspidosperma olivaceum Müll. Arg. and A. polyneuron Müll. Arg. The first, popularly known as "peroba-branca", is a source of indole alkaloids that are recognized for their antitumor activity. The second, known as "peroba-rosa", is used by some people for treating malaria. To contribute to the knowledge about Brazilian medicinal plants and potential vegetal drugs, a morpho-anatomical analysis of the leaves and stems of these tree species was carried out. The botanical material was fixed, sectioned and stained using standard techniques. Histochemical tests were performed and the material was also analyzed using a scanning electron microscope. Aspidosperma olivaceum and A. polyneuron are morphologically similar, both presenting alternate, simple, elliptic-lanceolate leaves. The leaves are hypostomatic with anomocytic stomata and have non-glandular trichomes. In the stem, there are peripheral phellogen, lignified fibers and some stone cells in the cortex and pith, as well as numerous gelatinous fibers near the phloem. Prismatic calcium oxalate crystals and laticifers are present in the leaves and stems. Unlike A. olivaceum, A. polyneuron also has cyclocytic stomata, predominantly unicellular non-glandular trichomes and a biconvex midrib with a sharper curve on the adaxial side. In addition, A. olivaceum differs because it has some idioblasts with phenolic content.

Morpho-anatomical study of the leaf and stem of pau-alecrim: Holocalyx balansae

Holocalyx balansae Micheli belongs to the Fabaceae family and is called pau-alecrim in Portuguese. In folk medicine, it is indicated to treat heart, hepatic and digestive upsets, as well as being considered anti-septic and diaphoretic. This work aimed to study the morpho-anatomy of the leaf and stem of this native medicinal species, in order to increase knowledge of the Brazilian flora and to contribute to pharmacognostic quality control. Samples of mature leaves and young stems were fixed and either sectioned free-hand or embedded in glycol-methacrylate and sectioned by microtome, then stained. Microchemical tests and scanning electron microscopy were also performed. The leaves are alternate, compound and paripinnate, and the leaflets have a lanceolate shape. Anomocytic and anisocytic stomata are found exclusively on the abaxial surface. The mesophyll is dorsiventral and the midrib, in cross-section, is flat on both sides, showing one collateral vascular bundle, encircled by a sclerenchymatic and crystalliferous sheath. The rachis and petiole present a collateral vascular bundle with a centric arrangement. The stem presents phellogen localized superficially. In the vascular cylinder, there is a sclerenchymatic sheath and continuous phloem and xylem cylinders, both traversed by narrow rays. Prismatic crystals of calcium oxalate are present in the leaf and stem.