Figure 2.

(a) Effects of different alcoholic extracts of CP on H9c2 cardiomyocytes cell viability decreases induced by H₂O₂ (700 μM for 6 h). H9c2 cardiomyocytes were pretreated with 20 μg/mL alcoholic extracts of propolis, that is, 70% ethanol fraction (70E), 95% ethanol fraction (95E), 40% ethanol upper fraction (40EU), and 40% ethanol lower fraction (40EL). Quercetin (5 μM) served as a positive control. ^∗∗P < 0.01 versus oxidative injury group, ^##P < 0.01 versus control group, and ^ξξP < 0.01 versus 70E group. (b) Effects of different fractions from CP using different solvents on H9c2 cardiomyocytes cell viability decreases induced by H₂O₂ (700 μM for 6 h), that is, petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EtOAc), and acetone fractions. Quercetin (5 μM) served as a positive control. ^∗∗P < 0.01 versus oxidative injury group, ^##P < 0.01 versus control group, and ^ξξP < 0.01 versus EtOAc group. (c) Effects of different subfractions (fractions 1 to 7) from CP EtOAc/acetone fraction on H9c2 cardiomyocytes cell viability decreases induced by H₂O₂ (700 μM for 6 h). ^∗∗P < 0.01 versus oxidative injury group, ^##P < 0.01 versus control group, and ^ξξP < 0.01, ^ξP < 0.05 versus fraction 3 group.