A 0.1-ml aliquot of methanolic extract was diluted with 0.4 ml of deionised water, then the obtained solution was mixed with 2.5 ml of 0.2 M Folin–Ciocalteau reagent and 2 ml of 7.5% (m/v) sodium carbonate solution. After 2 h of incubation, the absorbance was measured against a blank, using UV/Vis spectrophotometer