Polyphenols assessment and antioxidant capacity of six species of the Atlantic Forest

Abstract

Medicinal plants are important sources of antioxidants and in its activity have been implicated compounds such as polyphenols. This study aimed to quantify total polyphenols and measure antioxidant capacity of six different species used in folk medicine:  Leandra sp, Elephantopus mollis Kunth, Alternanthera dentata Moench, Sambucus australis Cham. & Schltdl., Tillandsia usneoides L. and Psidium guajava L. Polyphenolic compounds  and antioxidant capacity of the aqueous and ethanolic extracts were analyzed by Folin-Ciocalteu and by 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, respectively. The concentration of polyphenols found in the aqueous extracts were from 0.26 to 12.84 mg/g and in the ethanolic extracts were from 10.56 to 17.03 mg/g. The levels of antioxidant capacity obtained in aqueous extracts were from 17.8 to 89.4% and among the ethanolic extracts were from 79.05 to 87.1%. The correlation between antioxidant capacity and polyphenols content of aqueous and ethanolic extracts tested were R₂ = 0.26 and R₂ = 0.74, respectively. All species studied here showed a high antioxidant potential, especially in the ethanolic extracts.