*3.4. Total Flavonoid Content*

The total flavonoid content (TFC) of the *H. acetosella* extracts was determined as described by Ryu et al. [7]. Each extract sample (0.2 mL) was added to 4 mL double-distilled water and 0.3 mL of 5% NaNO2 in a flask. The samples were left for 5 min, then 0.3 mL of 10% AlCl3 was added. After 6 min, 2 mL NaOH were added then made up to 10 mL with double-distilled water. The absorbance was then measured at 510 nm. TFC was calculated using a calibration curve of quercetin equivalents.
