The total flavonoid content (TFC) was determined as previously described by ท The extract (250 mL) was diluted with 1.25 mL distilled water. Sodium nitrite (75 mL) was added and the mixture was allowed to stand for 6 min. Further, 150 mL of aluminum chloride was added and the mixture was allowed to stand for 5 min. After that, 0.5 mL of sodium hydroxide (40 g/100 mL) was added and solution was mixed well. The absorbance was measured immediately at 510 nm using a spec- trophotometer. Catechin was used as standard and results were reported as microgram catechin equivalent (CE)/g of sample.