HPLC-MS; flavonoids; apiin; antioxidants; lipid peroxidation
Oxidative stress, resulting from the imbalance between the production and elimination of free radicals, is of great importance in the processes of aging and cell death. The intake of condiment herbs, as salt substitutes, has been stimulated by the fact that they contain bioactive compounds capable of deactivating free radicals. The objective of this work was to determine the content of phenolic compounds and total flavonoids (Folin-Ciocalteu and Aluminum Chloride method, respectively), to evaluate the antioxidant capacity (DPPH and FRAP methods), and to promote a phytochemical screening of the aqueous leaf extract of Petroselinum crispum var. crispum (parsley). Twenty-nine glycosylated flavonoids were identified in the extract, with apiin being the main compound; from the acid hydrolysis of the apiin, the aglycone apigenin (90% purity) was obtained. A high content of phenolics (12.49 ± 1.70 mg GAE / g of parsley extract) and total flavonoids (15.05 ± 2.20 mg of quercetin equivalents / g of parsley extract) were quantified in parsley, in addition to high antioxidant activity (EC50 - 15.50 mg.mL-1, DPPH method) and (189.8 mM Fe (II) / mg of dry plant extract - FRAP method). In vivo tests with Saccharomyces cerevisiae cells showed low toxicity of the aqueous extract of the parsley, however it revealed a high dose-dependent antioxidant potential, mainly in the lipoperoxidation test. In addition, the glycosylated flavonoid apiin also showed antioxidant action on yeast cells under oxidative stress in the cell viability assay (0.1 mM) and lipid peroxidation (0.01 and 0.1 mM), while apigenin was slightly antioxidant. Therefore, it is likely that the antioxidant activity of apiin is related to the total antioxidant capacity of parsley.