Otimização da extração de compostos fenólicos, atividade antioxidante, antimicrobiana e antiproliferativa de sementes de Myrciaria dúbia (H.B.K.) McVaugh e Myrciaria cauliflora (Mart.) O. Berg

Abstract

Camu-camu (Myrciaria dubia), fruit native to the Amazon region, and jabuticaba (Myrciaria cauliflora), native fruit in much of Brazil, are considered sources of phenolic compounds, carotenoids, vitamins and minerals. Seeds of camu-camu and jabuticaba represent about 25% of the fruits, however, this by-product is generally discarded without valorization and use of its chemical constituents. Using waste from the processing is a form of exploitation and conversion in coproducts with greater added value. In this scenario, the aim of this study was to evaluate the solvents effects (water, ethyl alcohol and propanone) and maximize the extraction of bioactive compounds, characterize the phenolic composition of camu-camu and jabuticaba seeds extracts, determine the antioxidant, antimicrobial, and antiproliferative in vitro activities. Firstly, the simplex-centroid mixture design, increased with three internal points, was used to evaluate the isolated effects, binary and ternary solvents mixtures. For this, two fruits seeds extracts were characterized based on in vitro methods of total phenolic compounds, antioxidant activity and inhibition of lipid peroxidation. The results were evaluated by multiple linear regression (RLM), in order to establish a mathematical relationship between the factors (solvents types) and the responses. In 43.3% of propanone, 40.7% of water and 16% of EtOH for camu-camu, and 52% of water and 48% of propanone for jabuticaba were found high values of total phenolic compounds (TPC), total flavonoids (TF), and condensed tannins (CT). Likewise, the in vitro antioxidant activity, evaluated by the DPPH radical capture ability, Folin-Ciocalteu reducing ability, inhibition of lipid peroxidation and Cu2+ chelating ability, also showed high values and showed to be correlated with content of TPC, TF and CT. Subsequently, the identification and quantification of 17 and 13 phenolic compounds of camu-camu and jabuticaba seeds optimized extracts, respectively, were performed by high performance liquid chromatography (HPLC). The two extracts tested were able to inhibit the growth of A549 cancer cell lines (IC50 camu-camu=581.1 g/mL and IC50 jabuticaba=310.7 g/mL) and HCT8 (IC50 camu-camu=630.8 g/mL and IC50 jabuticaba=382, 2 g/mL), showing antiproliferative effects. It was found antimicrobial action against Pseudomonas aeruginosa, Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Saccharomyces cerevisiae. In general, the solvent system under study was responsible for modifying the extract polarity and providing increased extraction yield of bioactive compounds. Higher solubilization and differentiation of phenolic composition was obtained since the water was responsible for dissolving hydrophilic compounds, EtOH, by dissolving polar and apolar substances, and propanone, capable of breaking hydrogen bonds formed between phenolic and carboxylic groups of proteins. In technological terms, this is the first work to report the optimization of the camu-camu seed solvent system.