Radical-scavenging activity of extracts from Cordia verbenacea DC obtained by different methods

The possibility of using the leaves of Cordia verbenacea as a new source of natural antioxidant compounds was investigated. In the present work, extracts from C. verbenacea were obtained using different extraction methods: supercritical fluid extraction (SFE), Soxhlet (SE), hydrodistillation and maceration, with the objective to evaluate the methods in terms of yield and antioxidant potential. The high-pressure technique was applied using pure CO2 and CO2 with co-solvent at different temperatures and pressures (30, 40 and 50 degrees C and 100, 200, and 300 bar). Organic solvents with different polarities were used to obtain extracts by low-pressure extraction processes. The extracts were evaluated according to their antioxidant activity using total phenolic content, scavenging abilities on DPPH radical, total antioxidant activities (ABTS(center dot+)), superoxide anion radical-scavenging (O-2(center dot)) and protection against lipid peroxidation in vitro (LPO). Ethyl acetate fraction obtained by maceration and extract isolated by SE using 25% aqueous mixture of ethanol possessed the highest scavenger activity against DPPH radical (IC50 = 9.2 +/- 0.4 mu g/ml, IC50 = 27.4 +/- 0.1 mu g/ml, respectively). The SFE with 8% ethanol as a co-solvent produced extracts with distinguished increase in the antioxidant activity. The Soxhlet extract with ethyl acetate exhibited a strong reduction of lipid peroxidation (IC50 = 209 +/- 3 mu g/ml) value comparable to the standard rutin (IC50=203 +/- 2 mu g/ml). The results indicate that extracts of C. verbenacea have important potential as a source of bioactive compounds with antioxidant activity. (C) 2010 Elsevier B.V. All rights reserved.