Avaliação microscópica, química e cardiovascular de Baccharis artiulata (Lam.) Pers. (ASTERACEAE)

Abstract

The genus Baccharis comprises around 440 species, many of them used in folk medicine to treat a wide variety of diseases. Baccharis articulata (Lam.) Pers., popularly known as carqueja, carquejinha or carqueja-doce, is used in traditional medicine as a diuretic, digestive and antidiabetic. It is a shrubby species with a light green to grayish-green color and bialate branches. Due to its morphological similarities, it can be easily confused with other species that have the same popular name of carquejas. Although it is widely used, there are few studies on the pharmacological and toxic activity of B. articulata. The aim of this study was therefore to evaluate the species microscopically to identify botanical markers that help differentiate it from other carquejas, as well as its phytochemical characterization, its toxicological potential and its capacity for cardiovascular therapy as a hypotensive. The light microscopy, polarized light microscopy and scanning electron microscopy analyses were carried out in order to highlight anatomical markers of the species. Energy dispersive x-ray spectroscopy and Raman spectroscopy analyses determined the composition and hydration state of the crystals. Phytochemical characterization was obtained using ultra-performance liquid chromatography coupled with mass spectrometry. The toxicological potential was assessed through acute toxicity and genotoxicity studies and the cardiovascular activity was evaluated through the effects of the extract on blood pressure and heart rate, as well as assessing the pathways involved in the hypotensive effect. New morphoanatomical features were revealed, such as the presence of eleven crystalline morphotypes, namely: bipyramidal simple, bipyramidal rectangular, rectangular pyramidal, styloid, cuneiform, tabular, druse, arrow-type crystal, rounded crystalline sand, styloid crystalline sand, and bow-tie sand, which indicated the elemental chemical composition of calcium oxalate. As for the type of hydration, both monohydrated and dihydrated crystals were detected. Thirteen peaks were identified in the phytochemical characterization, namely: quinic acid,

neochlorogenic acid, chlorogenic acid, caffeic acid, 5-O-feruloilquinic acid, apigenin- C-pentoside-C-hexoside, 3,4-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid,

glucuronyl-quillaic acid, caffeoyl-glucuronyl-trihydroxyoleanolic acid, acetyl-caffeoyl- glucuronyl-dihydroxyoleanolic acid. In terms of toxicity, B. articulata did not appear to

be toxic at a concentration of 2000 mg/kg, nor did it prove to be mutagenic at concentrations of 30, 100 and 300 mg/kg. In the cardiovascular analysis, we observed that the aqueous extract caused a decrease in blood pressure in SHR rats. Providing additional data to that found in the literature on B. articulata are of great importance in the systematics of the species, as they will serve as a basis for future studies involving the carquejas group, or even the genus Baccharis. In addition, proving the therapeutic potential of the species could help in research into the treatment of cardiovascular diseases.