Obtenção de compostos fenólicos e avaliação da citotoxicidade do extrato de murici (Byrsonima crassifólia)

Abstract

The Amazon Rainforest is recognized for its rich biodiversity, including a variety of therapeutic and edible plants with distinct characteristics. One species with high regional potential is murici, Byrsonima crassifolia (L.) Kunth, a native fruit of Brazil, especially from the northern and northeastern regions, with a pulp rich in antioxidant compounds such as carotenoids, vitamin C, phenolic compounds, and unsaturated fatty acids. In order to investigate the process of phenolic compound extraction from murici fruit, the technique of ultrasound-assisted extraction was used. This technique allows for a more efficient and rapid extraction of the desired compounds by applying ultrasound to facilitate mass transfer between the solvent and the solid matrix of the fruit. The fruits were acquired from a market in Manaus-AM, cleaned, and stored at -18°C until transported to the Federal University of Fronteira Sul - UFFS, Campus Chapecó-SC. To evaluate the influence of the drying method, the fruits were divided into two parts, with one part dried in an oven with air circulation and the other part dried in a freeze dryer. The extraction time was evaluated through a kinetic study, while process variables (temperature, solid/liquid ratio, and solvent concentration) were assessed using the experimental design technique of Central Composite Rotatable Design (CCRD). The extracts obtained during the experiments were evaluated for total phenolic compounds (TPC) quantified by the Folin-Ciocalteu method, and for total antioxidant activity (TAA) assessed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (Ferric Reducing Antioxidant Power) methods. For the best experimental conditions, the chromatographic profile of the extracts was obtained using high-performance liquid chromatography coupled with mass detector (HPLC-MS). The results showed that the biomass dried in the freeze dryer at a temperature of 80°C, a solid/liquid ratio of 25 mg/mL, and an ethanol concentration of 60% resulted in a quantification of total phenolic compounds of 39.84 ± 0.31 mg GAE/g dry sample and a total antioxidant activity of 229.31 ± 2.58 μmol TE/g dry sample. The extract obtained under the best experimental condition was freeze-dried and characterized for its phenolic profile, identifying syringic acid as the compound present in the highest concentration. Subsequently, the study analyzed the cell viability of healthy CCD 1059 Sk cells and cancerous SK-Mel-28 cells exposed to the murici extract. The results showed that the murici extract had no detrimental effects on healthy cells, with a proportional increase in cell viability observed with increasing extract concentration. However, in cancerous cells, the murici extract also increased cell viability, indicating that the extract is not viable for the treatment of these cancer cells. It is important to consider that murici contains a high sugar content, which may influence the cell viability of cancer cells. Additionally, tests with concentrated compounds (quercetin and p-coumaric acid) from murici did not show a significant increase in cell viability. In summary, the murici extract did not negatively affect healthy cells but did not demonstrate efficacy in treating SK-Mel-28 cancer cells, indicating the need to explore other approaches for cancer treatment.