Total flavonoids in extracts were determined using the aluminum
chloride colorimetric method of Change et al. [12]. The
appropriate dilution of extracts (0.5 ml) was mixed with 1.5 ml
of 95% ethanol, followed by 0.1 ml of 10% aluminum chloride,
0.1 ml of 1 M potassium acetate and 2.8 ml of distilled
water. After incubation at room temperature for 30 min, the
absorbance of the reaction mixture was measured at 415 nm.
The flavonoid content was calculated using a standard calibration
of rutin solution and expressed as micrograms of rutin
equivalent (RE) per gram of sample.