Avaliação do Potencial Antioxidante, Genotóxico e/ou Antigenotóxico e Estudo Químico de uma amostra de Própolis da Região do Cerrado de Mato Grosso do Sul

Abstract

Propolis is a complex resinous bee product whose chemical composition depends on the botanic biodiversity of the region where it is produced. It is used as a folk medicine against several diseases. In view of its widespread therapeutic use and few studies on its mechanism of action and also considering that the biological properties of the propolis produced in the Cerrado of Mato Grosso do Sul have not been previously investigated, the aim of the present study was to evaluate the genotoxic effect of propolis obtained from this biome on Drosophila melanogaster wing cells, through SMART/wing test. A sample of propolis was successively extracted with hexane and ethanol to yield the crude extracts HEP and EEP, respectively. The EEP extract was further submitted to partition with the hexane (HPP), dichloromethane (DPP), ethyl acetate (APP) and n-butanol phase (BPP). We evaluated the activity against the DPPH radical and determined the total phenolic content (TP) of the samples of interest. The volatile constituents were obtained by steam distillation method in Clevenger extractor, then an aliquot of essential oil (OEP) was subjected to GC/MS for after analysis of Kovats index. To access the genotoxic effects of HEP, EEP, APP and BPP in D. melanogaster wing cells, two different crosses were used: the standard (ST) and the high bioactivation (HB) crosses. Several chromatographic techniques resulted in the isolation of nine substances: acetilisocupressic acid (1), artepillin C (2), p-coumaric acid (3), dihydrocoumaric acid (4), caffeic acid (5), aromadendrin (6), trans-nerolidol (7), spathulenol (8) and 3-epi-lupeol (9), their structures have established on the basis of 1H and 13C NMR data. The most significant activity antirradicalar and TP were observed at polar phases: EEP, APP and BPP. Under the experimental conditions, no genotoxicity was shown by PEH, PEE, PFA and PFB at all evaluated concentrations (12.0, 6.0 and 3.0 mg/mL). Simultaneous treatment with different concentrations of EPP and Doxorubicin (DXR) led to a reduction in the frequency of spots compared to the treatment with DXR alone at ST cross, while at HB cross it display genotoxic effects, indicating the caracteristic of a “Janus”. Inhibitory effects were also observed for all doses of the PFB (1.37, 0.69 and 0.345 mg/mL) associated with DXR in both crosses (ST and HB), and the highest dose (1.37 mg/mL) in HB cross showed inhibition of 96.2% of the spots. Among the compounds isolated, the 1 was tested and showed genotoxicity at the highest concentration (1.0 mg/mL) in HB cross, namely this diterpene requires bioactivation by cytochrome P450. This is the first report about genotoxic effect of compound acetilisocupressic acid (1). No genotoxicity was found for EOP at all concentrations tested (0.05, 0.1 and 0.2%) in fly of the ST cross, this result may be related to major compounds trans-caryophyllene, δ-cadinene, and spathulenol alloaromadendrene of EOP. These results contribute to the knowledge of chemical composition and biological activity of a propolis sample from the Cerrado of Mato Grosso do Sul as promising candidates for novel anticancer agents.