Folk medicine, biological activity, and chemical profiles of Brazilian Acanthaceae (Lamiales) - A review.

INTRODUCTION: The botanical family Acanthaceae (order Lamiales) potentially comprises 4900 species in 191 genera with extensive morphological, habit and habitat diversity. The family is widely distributed throughout the world but is especially rich in tropical and subtropical regions. Many of its species have great ornamental importance and are broadly used for medicinal purposes in several countries of Asia and Africa. Brazil is a main center of diversity of the family, where they are distributed across all its biomes, mainly in the herbaceous-shrub stratum. Medicinal investigations about Brazilian species are scarce, the exception being a single native species, Justicia pectoralis Jacq., that is widely used and studied chemically. AIM OF THE REVIEW: This work compiled studies that indicated folk medicinal use, investigated biological activity, or evaluated the chemical composition of Brazilian species of Acanthaceae. MATERIAL AND METHODS: Medicinal uses, investigations of biological activities and chemical data were collected and summarized through bibliographic surveys. Tables were compiled to standardize the information and the appropriate references were gathered for each species. Registration of chemical components used in the treatment of ailments and in preserving health were emphasized with the aim of stimulating future investigations. RESULTS: The breadths of habitats and morphologies of the family are directly related to its chemical diversity, as confirmed here for Brazilian species. Although the investigated species represent less than 9% of the total richness of the family in Brazil, they encompass a great diversity of chemical substances. The data indicated folk medicinal uses for 26 species and biological tests for 23, while 30 species were investigated chemically. Ruellia and Justicia were the most researched genera with 12 and 11 species, representing approximately 14% and 7% of Brazilian species of each genus, respectively. Two species are native to other countries but become naturalized in Brazil. Studies of native species were carried out in different countries around the world, with many reports of medicinal uses and biological tests. Examples of uses include anticancer and antidepressant actions, as well as activities against respiratory problems and other diseases. CONCLUSIONS: This work highlights the chemical and biological diversity of the studied Brazilian species of Acanthaceae, which emphasizes the need to expand studies with native Brazilian species.

Ruellia angustiflora (Nees) Lindau ex Rambo: extraction and characterization of phenolic compounds and evaluation of antiradical, photoprotective and antimicrobial activities.

Ruellia angustiflora is a shrub popularly known as flower of fire, used in traditional medicine as a healing agent. This study aims to verify the presence of characteristics of pharmaceutical interest in extracts from the root, stem and leaves of this species. The ideal time for ultrasound-assisted extraction is 60 min with a solid-liquid ratio of 1% (w/v). The kinetics of the reaction of the extracts with DPPH is biphasic, and IC50 values are related to the total phenolic compounds. Five phenolic compounds were identified in the extracts, where ferulic acid, rutin and quercetin showed to be the main responsible for the antiradical activity. The extracts displayed considerable photoprotective activity, mainly Ra-LE (SPF = 23). Ra-RE showed an inhibition halo similar to erythromycin against Streptococcus pyogenes. Taken together, these data reveal that Ruellia angustiflora is a source of phenolic compounds and has relevant antiradical, photoprotective and antibacterial activities.

Chemical composition determination and evaluation of the antibacterial activity of essential oils from Ruellia asperula (Mart. Ex Ness) Lindau and Ruellia paniculata L. against oral streptococci.

This study investigated the chemical composition and evaluated the antibacterial and antibiofilm activities of essential oils (EOs) extracted from Ruellia asperula (EORA) and Ruellia paniculata (EORP) against oral streptococci. The EO constituents were analyzed by gas chromatography/mass spectrometry. The antimicrobial potential of EOs was evaluated using the minimum inhibitory concentration, minimum bactericidal concentration, and time-kill determination. Furthermore, the quantification of total biomass and the number of viable cells in the biofilms were evaluated. The major constituents of EORA were cariophylla-4(12)-8-(13)-dien-5ß-ol (14.1%), (ß)-caryophyllene (22.7%), and caryophyllene oxide (29.4%). For EORP, the major constituents were (ß)-caryophyllene (11.0%), spathulenol (13.1%), and δ-amorphene (14.9%). The tested EOs exhibited antibacterial activity against planktonic growth and biofilm formation. Thus, the EOs from R. asperula and R. paniculata prove to be promising alternatives for bacterial growth control and biofilm formation prevention of oral streptococci.

Chemical study, antioxidant activity, and genotoxicity and cytotoxicity evaluation of Ruellia angustiflora.

Ruellia angustiflora (Acanthaceae) is known as flower-of-fire, and its leaves are traditionally employed to promote wound healing. This study was aimed at extracting and characterizing the chemical constituents of the extracts of R. angustiflora obtained by ultrasound-assisted and supercritical fluid extractions, and subsequently investigate their antioxidant potential and cyto-genotoxicity. The extract obtained by ultrasound (UAE-EtOH) was characterized by ultraperformance liquid chromatography-mass spectrometer (UPLC-MS), and the extract obtained via supercritical fluid (SFE-CO2) by gas chromatograph-mass spectrometer (GC-MS). The antioxidant potential was verified by the antiradical activity against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and the cyto-genotoxicity evaluation to test cell viability and DNA damage was performed in peripheral blood mononuclear cells (PBMC) cultures. The SFE-CO2 extract presented some fatty acids, triterpenes, tetraterpenes, tocopherols and phytosterols. The UAE-EtOH extract contained phenolic acids and flavonoids, and showed the highest antioxidant capacity. Neither extract was genotoxic or cytotoxic at the tested concentrations.

Evaluación fitoquímica preliminar y actividad hipoglicemiante aguda del extracto acuoso de la raíz de Ruellia tuberosa L. en ratas con diabetes experimental / Preliminary phytochemical screening and acute hypoglycemic effects of the aqueous extract of Ruellia tuberosa L. root in experimental diabetes in rats

La diabetes es uno de los principales problemas de la salud pública mundial. En Venezuela se utilizan varias plantas para el tratamiento de la diabetes, sin embargo, los estudios farmacológicos de estas especies han sido insuficientes. Ruellia tuberosa L. (Acanthaceae) es una de estas plantas de uso en la medicina tradicional. En los últimos años, he mos estudiado la farmacología del extracto acuoso de la raíz de la R. tuberosa (RT) demostrando su actividad an ti - inflamatoria, antioxidante y protectora frente al daño renal inducido por la diabetes. El tratamiento subcrónico con este extracto fue capaz de inhibir el aumento de la glucosa sanguínea en ratas con diabetes inducida por la es - treptozotocina (ETZ). En este trabajo se evaluó el perfil fitoquímico preliminar y el contenido de polifenoles totales del extracto de RT, así como también sus efectos agudos sobre la glicemia en ratas diabéticas. Los resultados muestran que el RT produjo un efecto hipoglicemiante tanto en los animales controles como en las ratas con diabetes inducida por la ETZ, con porcentajes de variación de la glicemia comparables con el hipoglicemiante oral de referencia, la glibenclamida. Este extracto mostró la presencia de un alto contenido de polifenoles, lo que posiblemente se encuentre asociado con su actividad antidiabética y antioxidante, reflejada a través de la reacción del RT con el radical 2,2- difenil-1-picrilhidrazil (DPPH). Todos estos hallazgos contribuyen con la validación del RT como un extracto antidiabético, el cual involucran la disminución de la glicemia y el decremento del estrés oxidativo. Asimismo, sienta las bases para el aislamiento y caracterización de los componentes responsables de su actividad farmacológica.