AbstractThe aim of this study was to evaluate the influences of variables of preparation on total flavonoids content from extractive solution of Lippia sidoides Cham., Verbenaceae. Thus a 23 factorial design was used to study the importance of plant proportion, the extraction method and solvent on the extraction of flavonoid. The methodology of determination of chemicals in factorial design was validated according to the parameters required by Brazilian Health Agency. The extraction solution was selected through a full factorial design where the best conditions to achieve the highest content of flavonoids were: 7.5% (w/v) of plant with ethanol 50% (v/v) as solvent. The polyphenols content was determined by LC method and its relationship with the antioxidant and free radical scavenging activities was evaluated. The free radical scavenging activities and antioxidant potentials were determined for different concentrations using various in vitro models. Our results indicate that extracts exhibited a significant dose-dependent antioxidant effect as evaluated by TRAP/TAR assays. Besides, we observed an antioxidant activity against hydroxyl radicals and nitric oxide, and protection against lipid peroxidation in vitro. Our results suggest that the extract presents significant in vitro antioxidant potential indicating promising perspectives for its use as pharmaceutical/or food additive.