Extração e identificação de flavonoides das folhas de Pilocarpus microphyllus Stapf ex. Wardeworth e avaliação da atividade antioxidante e perfil neuroprotetor

Abstract

Flavonoids comprise a group of secondary metabolites of great structural diversity, whose therapeutic properties have gained great interest in the last decades. Jaborandi (Pilocarpus microphyllus Stapf ex Wardeworth), of proven medical use, is of great importance in the pharmaceutical market, since its leaves are extracted pilocarpina used in the treatment of glaucoma. Although some flavonoids have been described in the genus Pilocarpus, there are no studies of prospecting and identification of flavonoids of P. microphyllus leaves. In this context, the present work aims to extract and identify the flavonoids from jaborandi leaves and investigate the pharmacological potential. The ethyl acetate fraction (FAcOEt) obtained from the methanol extract (EM) was evaluated for its antioxidant activity by means of the DPPH and ABTS radical capture assay, in addition to the characterization of the electrochemical profile of the fraction to observe the redox processes Sample. In the DPPH assay, the fraction revealed EC 50 of 0.4 mg/mL. The fraction presented TEAC value of 819 μmol trolox/g FAcOEt. The sample exhibited redox processes at low potentials, indicating promising antioxidant activity. The trial of induction of peripheral neuropathic pain by sciatic nerve compression in wistar rats to determine the Mechanical Nociceptive Threshold (LNM) in the von Frey test, evidenced the probable effect of this fraction against the reactive oxygen forms (ROS) involved in the process Pathophysiology of neuropathic pain, revealing significant activity at the dose of 100 mg / kg. The characterization of FAcOEt constituents by UV-Vis spectrophotometry, infrared spectrophotometry, HPLC, mass spectrometry and cyclic voltammetry, raised the hypothesis that the major component of this fraction is flavone chrysin, whose solubility properties in HPLC are very close to of flavone quercetin, and revealed the characteristic presence of this group.