The method is based on the reaction between the flavonoids and aluminium chloride, forming a yellow complex. Four millilitres of deionised water and 0.3 ml of sodium nitrate solution (15 g/100 ml) were added to 1 ml of appropriately diluted methanol extract. After that 0.3 ml of aluminium chloride methanolic solution (10 g/100 ml) and 4 ml of sodium hydroxide solution with concentration (4 g/100 ml) were added to the resulting solution and then the whole sample was diluted with deionized water to a final volume of 10 ml. The mixture was stirred and left to stand for 15 min and finally absorbance was measured at 510 nm.