Abstract
Two different microemulsions systems (SME) were performed using a mixture of Tween 80 and Span 20 (3:1) as surfactant, isopropyl myristate as oil phase, and bidistilled water consisting on two different compositions (SME-1 AND SME-4). In one of these systems ethanol was included as cosurfactant (SME-1) and for SME-4 ethanol-free, which were used as solubilizing agent on evaluation of the antioxidant potential of Anacardium occidentale. The antioxidant activity of a methanolic extract (MeOH, obtained from stem bark of this plant), as well as its two fractions FO (fixed oil) and FT (a polar fraction rich in tannin) were evaluated in DPPHmethod. Due to the poor solubility of the tannin fraction, it was evaluated after its solubilization in SME-1 and SME-4 systems. The obtained results showed high antioxidant activity for MeOH extract (CE50 = 42,47 0,14 g/mL) and FT (CE50 = 39,27 1,07 g/mL for FT-SME-1, and CE50 = 42,20 5,20 g/mL for FT-SME-4), but no activity for the FO fraction at 710 g/mL was confirmed. These results indicated that the antioxidant activity of the MeOH extract corresponded to the presence of tannins constituents. The tested microemulsions systems do not caused any significant interference in the antioxidant activity results evidenced on the FT-SME-1 and FT-SME-4 fractions.