Abstract:

The oxygen radical absorbance capacity (ORAC) of flavonoids extracted from the bran of tartary buckwheat(Fagopyrum tartaricum (L.) Gaertn) from Youyang, Chongqing municipality (T1) and Xichang, Sichuan province (T2)was evaluated as well as cellular antioxidant (CAA) and antiproliferative activities on human liver cancer HepG2 cells.The results showed that the ORAC values of flavonoids extracted from T1 and T2 were (57.0 ± 3.5) and (73.6 ± 6.3) μmol TE/g,respectively, and the CAA values were (44.4 ± 5.2) and (52.5 ± 2.7) μmol QE/100 g by PBS washing; (32.9 ± 3.2) and(30.9 ± 2.2) μmol QE/100 g without PBS washing, respectively. The antiproliferative activity assay showed that at theconcentration of 21.9 mg/mL, the proliferation inhibitory rates of HepG2 cells by T1 and T2 flavonoids were approximately51% and 82%, respectively, when compared to control cells (P ＜ 0.01), and the corresponding EC50 (median effectiveconcentration) values were (23.0 ± 0.5) and (13.7 ± 0.1) mg/mL. Therefore, the flavonoids extracted from T1 and T2 hadsignificant CAA and anti-proliferative activities on human liver cancer HepG2 cells in vitro. This study shows that tartarybuckwheat bran can be considered as a resource of raw materials for functional foods.

Key words: Fagopyrum tartaricum (L.) Gaertn bran, flavonoids, cellular antioxidant activity, anti-proliferation, HepG2 cells