Extratos de folhas de araçazeiro (Psidium cattleianum Sabine) e de butiazeiro (Butia odorata) (Barb. Rodr.) Noblick & Lorenzi, obtidos por infusão aquosa e por extração com líquido pressurizado: descrição fitoquímica e prospecção de propriedades

Abstract

Brazil has the greatest genetic diversity and variability of plant species on the planet, which generates an environmental and technological asset, such as the phytochemical potential for applications in food or other field. In this context, araçazeiro and butiazeiro are fruits are rich in bioactive compounds with antioxidant and antimicrobial activities, whereas the leaves are a potential source of bioactive compounds. Therefore, it was decided to characterize the characterize the phytochemical compounds present in extracts of araçazeiro (Psidium cattleianum) and butiazeiro (Butia odorata) leaves, and to evaluate their antioxidant and antibacterial properties of these extracts. Leaf extracts were obtained through aqueous infusion (Al) and a pressurized liquid extraction system with water (PLE-W), ethanol (PLE-E) and a combination of water: ethanol (PLE-W:E). The study was carried out in two stages. Step 1 consisted of obtaining and chemically characterizing the extracts by liquid chromatography coupled to mass spectrometry (LC-MS/MS). In step 2, the biological potential was evaluated by testing the antioxidant activity in a rat brain model, using the method of reactive substances to thiobarbituric acid (TBARS) and reactive oxygen species (ROS) methods, and in yeasts; and antibacterial activity by Agar Diffusion Disc Spectrum of Action and by Minimum Inhibitory Concentration (MIC). For araçazeiro leaves extracts, PLE-W:E presented greater diversity of extracted compounds. Furthermore, all extracts had antioxidant activity against in vitro assays by TBARS, ROS, and yeast and showed inhibitory activity against pathogenic Gram-positive and Gram-negative bacteria. For butiazeiro leaves extracts, the greatest diversity and total concentration of phenolic acids and flavonoids were in PLE-E and PLE-W:E; all extracts exhibited an antioxidant activity by ROS, while only PLE-W and PLE-E had a protective effect against TBARS. For the antibacterial activity, only two Gram-positive bacteria were affected by the presence of the extracts, these being the PLE-W and PLE-E. This demonstrates that, among eight pathogenic bacteria tested, only two showed an inhibitory effect for the butiazeiro leaves extracts, as an alternative, araçazeiro leaves are a promising source of bioactive compounds. In this way, subsequent studies are required to explore the extracts protective properties of in vitro and in vivo assays, especially cytotoxicity assay regarding the health and safety concern of these extracts.