Capacidade antioxidante in vitro e avaliação da toxicidade aguda in vivo de extratos de folhas de Licania rígida Benth., Licania tomentosa (Benth.) Fritsch e Couepia impressa Prance (Chrysobalanaceae)

摘要

Licania rigida Benth., Licania tomentosa (Benth.) Fritsch, and Couepia impressaPrance (Chrysobalanaceae family) plants have long been used medicinally bythe people from Northeastern Brazil. Crude extracts and infusions of theseplants have been applied in the treatment of several conditions such asdiabetes and rheumatism, degenerative diseases with involvement of reactiveoxygen species (ROS). The aim of this study was to evaluate the aqueous,ethanolic, and hydroethanolic leaves extracts antioxidant capacity of thesespecies, using several in vitro assay systems (reducing power, DPPH●scavenging, the β-carotene linoleate model system and lipid peroxidationinhibition in rat brain homogenate, using thiobarbituric acid reactive substances- TBARS). The oral acute toxicity of aqueous extracts was also evaluated invivo. Results revealed that these extracts possess a potent reducing power andDPPH scavenging ability, as well as the ability to prevent TBARS formation inrat brain homogenate in a concentration-dependent manner. Regarding in vivooral acute toxicity of the aqueous species extracts, no toxic effects wereobserved upon evaluating physiological, hematological and biochemicalparameters. The presence of high levels of phenolics and flavonoids wasdetermined mainly in the ethanol extract. However, the C. impressahydroethanolic extract, fractionated with hexane, chloroform and ethyl acetatefor analysis by NMR 1H, showed more efficient results than the referenceantioxidant Carduus marianus. The classes of organics compounds weredetermined were phenolics in the fraction of ethyl acetate and terpenes inchloroform and hexane fractions. The ethil acetate fraction had the highestcontent of flavonoids and increased scavenging capacity of DPPH●, possibly bythe presence of phenolic compounds. Therefore, a detailed investigation of thephytochemical composition and in vivo study of the C. impressa hydroethanolicextract is suggested to characterize the active compounds of the species