Green-based methods to obtain bioactive extracts from Plantago major and Plantago lanceolata

摘要

P. major and P. lanceolata are two medicinal plants used extensively all over the world as remedies for a wide range of diseases. This study aimed to apply a sustainable recovery extraction to obtain bioactive extracts from the medicinal plants P. major and P. lanceolata. Different extraction methods were compared in terms of yield process, total phenolic content (TPC) and antioxidant and antibacterial activities. The methods used were: supercritical fluid extraction (SFE) with CO2 pure and with ethanol as co-solvent, conducted at temperatures from 40 to 60 degrees C and pressures from 10 to 30 MPa, and by Soxhlet (SOX) and ultrasound-assisted extraction (UE) with different solvents. High extraction yields were obtained by SOX with methanol (P. major) and by UE with EtOH-H2O (P. lanceolata). The moderate-polar and polar solvents presented the best TPC values and antioxidant performance, included the supercritical extraction of P. major with 5.0% of ethanol as co-solvent (EC50 276 +/- 1). SC-CO2 extract presented the best antibacterial activity, being more effective against the Gram-positive bacteria (Bacillus cereus). The results showed that the use of green recovery methods such as SFE and UE with polar solvents (EtOH-H2O and ethanol) provide high valuable extracts for Plantago species. (C) 2016 Elsevier B.V. All rights reserved.