Plantas medicinais conhecidas dos moradores do distrito de Riozinho, Cacoal/RO e aspectos morfoanatômicos, histoquímicos e fitoquímicos de Fridericia chica (Bonpl.) L. G. Lohmann - crajiru - Bignoniaceae

Abstract

The use of medicinal plants is a common practice among human populations. The objective of this work was to conduct an ethnobotanical study on medicinal plants known by a community located in the Municipality of Cacoal in the State of Rondônia. And contribute to the pharmacognostic characterization of one of the most common species of use in the community, Fridericia chica (Bignoniaceae). In the ethnobotanical study, the informants were selected through the "Snowball" technique. Semi-structured interviews and guided tours were conducted. The agreement of main use (AMU) and value of use (VU) of the species were calculated. The morphological, histochemical and phytochemical characterization of the F. chica leaves were performed according to the usual laboratory methodologies. The informants are mostly women. A total of 89 medicinal species were identified and distributed in 42 families, with Lamiaceae, Asteraceae and Fabaceae being the most represented families. Most of the medicinal plants used are herbaceous, which corroborates the idea of the importance of these "weed" plants in popular pharmacopoeias, and found in backyards, which reflects the importance of domestication of appropriate plants for therapeutic purposes. Plectranthus barbatus (Lamiaceae) and F. chica (Bignoniaceae) are the highest AMU and VU plants in the locality. The leaves are the vegetable parts most used in the preparation of the remedies, with infusion and decoction being the most common methods. The action of conventional medicine in the community seems to be a factor influencing the number of medicinal species used. The leaves of F. chica have uniseriate epidermis, dorsiventral mesophyll, are hypoestomatic with anomocytic stomata. Rosy-shaped glandular trichomes are distributed on both surfaces of the leaf blade, the central vein and the petiole. Coronal trichomes are present in the central rib and petiole region. The petiole is cylindrical, consisting of an unstrapped epidermis and fine cuticle. Histochemical tests indicated the presence of several secondary metabolites such as tannins, lignins, proteins and phenolic compounds and the phytochemical profile revealed the presence of flavonoids, anthraquinones and terpenes. These results indicate the great therapeutic potential of the species.