Determination of total polyphenols content (TPC)

TPC of the extract was determined according to the Folin-Ciocalteu method [26]. About 1 mg/mL of the sample solution was oxidized with 2 mL of 10% v/v Follin-Ciocalteu reagent (FCR) and 2 mL of 7.5% sodium carbonate. The mixture was incubated for 40 minutes at 45°C, and absorbance was measured at 765 nm using a UV/VIS spectrophotometer (JENWAY, UK). The TPC was calculated as a Gallic acid equivalent based on a standard calibration curve.