Figure 4.

In vitro anti-oxidative effects of the isolated quinochalcone C-glycosides against H₂O₂-induced cytotoxicity in cultured H9c2 cells. (A) Various concentrations of H₂O₂ (0, 0.37, 1.1, 3.3 and 10 mmol/L) were added onto cultured H9c2 cells, incubated for 1 h and determined with cell viability; (B) The isolated quinochalcone C-glycosides (60 μg/mL) were pretreated with H9c2 cells for 24 h before the addition of H₂O₂ (10 mmol/L) for cytotoxicity test as in (A). Vitamin C (1.1 mg/mL) served as a positive control (statistical significance is indicated as * p = 0.031 for hydroxysafflor yellow C vs. safflomin C; ** p = 0.005 for hydroxysafflor yellow C vs. saffloquinoside C; *** p = 0.001 for hydroxysafflor yellow C vs. control).