Composição química e atividade antioxidante do geoprópolis de Melipona quadrifasciata anthidioides

Abstract

Geopropolis is produced by stingless bees of Meliponini tribe, consisting of plant resins, mandibular secretions from bees and clay. Despite having therapeutic potential, there are few reports in the literature on the chemical composition and biological activities of this natural product. In this context, this study aimed to investigate the chemical composition and antioxidant activity of the stingless bee Melipona quadrifasciata anthidioides geopropolis, found in the state of Mato Grosso do Sul, Brazil. For this, were prepared two geopropolis extracts: ethanol (EEGP) and hydroethanolic (EHGP). The identification of flavonoids and phenolic compounds in the extracts were performed by colorimetric methods. Chemical analysis of the geopropolis was performed by high-performance liquid chromatography (HPLC). The antioxidant activity was detected by capture methods of the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS). Inhibition of lipid peroxidation assays were performed with human erythrocytes incubated with the oxidizing agent 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), and evaluated the inhibition of oxidative hemolysis, and levels of malondialdehyde (MDA). The chemical composition revealed the presence of total flavonoids and phenolic compounds. The EHGP has a higher concentration of phenolic compounds when compared to EEGP. HPLC analysis revealed the presence of diterpenes, and phenolic acids. Both extracts showed antioxidant activity, being able to capture free radicals DPPH and ABTS and inhibit lipid peroxidation in human erythrocytes when incubated with AAPH oxidizing agent. The EHGP shows better results compared to EEGP. In this context, ethanolic and hydroethanolic geopropolis extracts of M. q. anthidioides demonstrate therapeutic potential for the use in treatment or prevention of diseases related to oxidative stress.