Fig 1.
Chemical property of caffeic acid and its derivative.
(A) Structure of caffeic acid (CA) and pyrrolidinyl caffeamide (PLCA). (B) DPPH scavenging ability of CA and PLCA. Concentrations of two compound is from 0.03 μM to 300 μM (n = 3).
Fig 2.
Effect of CA and PLCA on myocardial I/R stress induced oxidative injury and changes of protein activity.
Cardiac oxidative injury and protein activity were shown in rats subjected to 1 h coronary artery occlusion and followed by 2 h reperfusion. (A) Troponin concentration, (B) lipid peroxydation, (C) catalase activity, and (D) HO-1 activity were measured. (n = 6) *P < 0.05 vs. control, # < 0.05 vs. IR, @ < 0.05 vs. IR+CA.
Fig 3.
Effect of CA and PLCA on protein expression after rat subjected to myocardial I/R stress.
Protein expression was shown in rats subjected to 1 h coronary artery occlusion and followed by 2 h reperfusion. (A) Original western blots were shown. (B) Ratios of p-AKT to AKT, (C) HO-1 to β-actin, (D) mnSOD to β-actin were measured. (n = 4) *P < 0.05 vs. control, # < 0.05 vs. IR, @ < 0.05 vs. IR+CA.
Fig 4.
Effect of CA and PLCA on cardiomyocyte exposed to H2O2.
(A) Cell viability was measured in cardiomyocyte exposed to H2O2 (10 μM ~ 3 mM). (B) Different doses of CA or PLCA was treated 1 h before H2O2 (300 μM) administration. (C) ROS generation in cardiomyocytes exposed to H2O2 was detected by CM-H2DCFD, and (D) the results of fluorescence density were also calculated. (n = 4) *P < 0.05 vs. control, # < 0.05 vs. H2O2, @ <0.05 vs. H2O2 + CA in same dose.
Fig 5.
The signaling pathway involved in PLCA against oxidative stress.
(A) Cell viability was measured in cardiomyocyte exposed to H2O2 (300 μM) in the presence or absence of PLCA combination with LY294002 (15 μM; PI3K inhibitor) or SnPP (10 μM; HO-1 inhibitor). (B) Original western blots were reported. (C) Ratios of p-AKT to AKT, (D) ratios of HO-1 to β-actin HO-1 activity, (E) ratios of mnSOD to β-actin, (F) HO-1 activity, and (G) catalase activity were measured. (n = 4) *P < 0.05 vs. control, # < 0.05 vs. H2O2, @ < 0.05 vs. H2O2+PLCA.
Fig 6.
Effect of PLCA on cardiac function after rat subjected to myocardial I/R stress.
Cardiac functions were measured by pressure-volume loop (PV loop). (A) Representative PV loop of each groups were shown. (B) Maximal slope of the systolic pressure increment (+dP/ dt), (C) maximal slope of the diastolic pressure decrement (−dP/dt), and (D) stroke work (SW) were measured. (n = 6)*P < 0.05 vs. control, # < 0.05 vs. IR.
Fig 7.
Effect of PLCA on myocardial I/R-induced neutrophil infiltration.
Myeloperoxidase (MPO) activity was detected in I/R-injured cardiac tissue. (n = 6) *P < 0.05 vs. control, # < 0.05 vs. IR.