Microwave-Assisted Extraction of Polyphenolics from Some Selected Medicinal Herbs Grown in Turkey

Abstract

The effect of microwave-assisted extraction (MAE) process on the antioxidant capacity/activity of three medicinal herbs from Turkey was investigated by electrochemical differential pulse voltammetric (DPV)- CUPric Reducing Antioxidant Capacity ( CUPRAC) assay. The optimal extraction time, temperature and solvent type were 6 min, 80 °C and 80% (v/v) methanol (MeOH), respectively. Microwave-assisted extracts of herbs (Hypericum scabrum L., Papaver fugax Poiret var. platydiscus Cullen , and Achillea vermicularis Trin.) were screened for total antioxidant capacity (TAC), total phenolic content (TPC) and ROS scavenging activities by employing different in vitro spectrophotometric assays. A positive correlation was observed between TAC-CUPRAC and TPC ( R 2 = 0.972). Similarly, a positive correlation was observed between TAC-CUPRAC and free radical scavenging (FRS) activity ( R 2 = 0.977). The order of FRS activities of tested samples was as follows: Hypericum scabrum L. > Achillea vermicularis Trin. > Papaver fugax Poiret var. platydiscus Cullen . These results suggest that these medicinal herbs provide promising antioxidant potentials as potential natural preservative agents in pharmaceutical industries.