Extração de Compostos Antioxidantes de Cissus sicyoides L. com Tecnologia Supercrítica e Determinação da Atividade Anti-inflamatória no Modelo de Lesão Medular

Abstract

Cissus sicyoides L. or Cissus verticillata L., also known as vegetable insulin, is a plant that has a potent anti-inflammatory activity, due to its chemical composition, which stands out for the presence of compounds with high antioxidant activity. Supercritical technology is an appropriate alternative to extract antioxidant compounds from plant matrices. In this sense, the objective of this thesis was to perform the extraction of antioxidant compounds present in C. sicyoides through supercritical technology, using CO2 and EtOH as a co-solvent, and subsequently, in the supercritical extract, to evaluate the anti-inflammatory effect in the spinal cord injury model. For this, in the first experimental stage of the thesis, the identification of phenolic compounds by HPLC and the cytotoxic effect, on human red blood cells, of the extract of leaves and stems of C. sicyoides obtained by supercritical extraction was evaluated, in the operating condition of 50 °C/ 400 bar and 10 % EtOH (𝜌𝐶𝑂2+𝐸𝑡𝑂𝐻 = 953 kg/m3), compared to the extract obtained by conventional extraction (Soxhlet) and, finally, the antiinflammatory effect in the spinal cord injury model was evaluated. In the analysis of the extracts by HPLC, the UV/Visible spectral data revealed compounds with absorption bands at wavelengths characteristic of glycosylated flavonoids. The supercritical extract did not show a cytotoxic effect, as there was no disruption of red blood cell membranes. The in vivo assay demonstrated an apparent reduction in cell concentration in the area surrounding the lesion in the treated animals, suggesting an anti-inflammatory effect of the supercritical extract in the spinal cord injury model. In the second experimental stage of the thesis, the aim was to study the antioxidants present in each part of C. sicyoides (fruits, flowers, leaves and stems). Samples were evaluated for CFT content by the Folin-Ciocalteu method, which ranged from 9.30 to 141.04 mg GAE/g of sample, of FT by complexation with aluminum chloride from 1.03 to 44.02 mg QE /g of sample, its antioxidant activity by the DPPH method, the EC50 value varied between 162.83 to 453.25 g of sample/g of DPPH and by the FRAP method the values were 199.14 and 241.26 μM ferrous sulfate/ g sample. Thus, leaves and stems before and after SFE are rich in antioxidants, which justifies the high FT content, as well as the higher antioxidant activity by the tested methods. Finally, in the SFE process it was possible to obtain an extract with potential antioxidant activity, which can be used for biological applications.