Evaluation of the antioxidant activity of the ethanol extract of Melochia tomentosa Linaeus (1735). / Avaliação da atividade antioxidante do extrato etanólico de Melochia tomentosa Linaeus (1735)

Abstract

Brazil has the greatest biodiversity in the world and there are no studies on several species of Brazilian flora. In this context, the genus Melochia has been studied as a possible source of alternative natural antioxidant. The objective of the present work was to investigate the antioxidant activity of the aerial parts (leaves and stems) of the candle (Melochia tomentosa L.) and to compare it with other natural and synthetic antioxidants. For that, the DPPH Trolox and DPPH Quantitative, FRAP, Total phenolic compounds and total flavonoids, and Phytochemical Prospection tests were performed. It was compared the antioxidant action of the ethanolic extract with Trolox, Gallic Acid, Quercetin and BHA, as well as with sources of natural antioxidants found in the literature. The values obtained for total phenolic compounds and flavonoids were respectively 1833.73 mg of gallic acid equivalent / g of dry extract and 133, 35 mg of quercetin equivalent / g of dry extract. A concentration of 3692.76 μmol Trolox / g dry extract was obtained for the Iron Reduction Power (FRAP) test. High sequestration activities were found for the DPPH radical with a percentage of antioxidant activity of 84.89% at the concentration of 75 μg / mL and with EC50 (Concentration of the antioxidant substance necessary to reduce the initial concentration of DPPH by 50%) from 37, 3 μg / ml. The results indicated a high content of phenolic compounds, a high potential in the sequestration of the DPPH radical and iron reduction, suggesting to the candle high antioxidant activity

Keywords

• vegetable extract
• flavonoids
• total phenols