Melatonin enhances captopril mediated cardioprotective effects and improves mitochondrial dynamics in male Wistar rats with chronic heart failure

Figures

• 

  Figure 1. Effects of captopril, melatonin, and their combination on systolic blood pressure (SBP). *p < 0.01 versus control, #p < 0.01 versus (ISO) group, €p < 0.01 versus ISO + captopril group and ₳p < 0.01 versus ISO + melatonin group.

• 

  Figure 2. Echocardiographic views for control (a), (ISO) (b), ISO + captopril (c) ISO + melatonin (d) and ISO + melatonin/captopril (e). Statistical analysis showing the percentage of left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) in all groups (f). *p < 0.001 versus control, #p < 0.001 versus (ISO) group, €p < 0.001 versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 3. Effects of captopril, melatonin, and their combination on serum cardiac injury markers; LDH (a), (CPK-MB) (b) and (cTnI) (c). *p < 0.001 versus control, #p < 0.001 versus (ISO) group, €p < 0.001 versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 4. Effects of captopril, melatonin, and their combination on cardiac oxidant/antioxidant markers; MDA (a) and (SOD) (b). *p < 0.001 versus control, #p < 0.001 versus (ISO) group, €p < 0.001 versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 5. Effects of captopril, melatonin, and their combination on cardiac inflammatory/ anti-inflammatory cytokines; (TNF-α) (a), (IL-6) (b), (iNOS) (c) and (IL-10) (d). *p < 0.001 versus control, #p < 0.001 versus (ISO) group, €p < 0.001 versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 6. Effects of captopril, melatonin, and their combination on cardiac apoptotic marker caspase 3(a) and fibrotic markers (TGF-β1) (b) and collagen-I (c). *p < 0.001 versus control, #p < 0.001versus (ISO) group, €p < 0.001versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 7. Effects of captopril, melatonin, and their combination on mitochondrial dynamics in the rat model of CHF parkin (a) & (PINK1) (b), (PGC-1α) (c), (Mfn2) (d) and (DRP-1) (e) parameters in rat’s myocardium. *p < 0.001 versus control, #p < 0.001 versus (ISO) group, €p < 0.001 versus ISO + captopril group and ₳p < 0.001 versus ISO + melatonin group.

• 

  Figure 8. H&E-stained heart tissue sections showing regularly arranged myofibrils (M) with narrow spaces in between in the control group (a,b). Distorted myofibrils with patches of fibrosis (F), haemorrhage (h) inflammatory cells (If), dilated congested blood vessels with perivascular cuffing (curved arrow) in ISO group (c–f). Improvement of myofibrils arrangement with wide spaces, dilated and perivascular cuffing in ISO/captopril group (g,h). Small areas of fibrosis (F), few cellular infiltration (If), perivascular cuffing and wide spaces in the ISO/melatonin group (i,j). Restoration of the normal arrangement of the myofibrils but areas of wide spaces and perivascular cuffing are still observed in the ISO/captopril/melatonin group (k,l).

• 

  Figure 9. Masson’s trichrome stained heart tissue sections showing collagen fibers (green color). In control group (a), wide areas of collagen deposition in the ISO group (b), few fibres of collagen around blood vessels in ISO + captopril (c) and ISO + melatonin group (d) but scanty patches of collagen fibers in noticed in ISO/captopril/melatonin (e). Morphometrical analysis shows an increased area percentage of collagen fibres in the ISO group (f). Scale bars 3A–3E = 200 µm.

• 

  Figure 10. Expression of Beclin 1 in studied groups. The immunohistochemical results showed high positive cytoplasmic immunoreactivity (brown colour) is detected in most of myofibers of the control (a) group. The immunoreactivity is seen in a few myofibers of the ISO group (b). Positive immunoreactivity in some myofibers in both ISO/captopril (c) and ISO/melatonin (d) groups. Positive immunoreactivity in many myofibrils in ISO/captopril/melatonin (e) group. (f) Morphometrical analysis showing a decreased percentage of Beclin-1 immunoreactivity in the ISO group. Scale bars 4A–4E = 50 µm.

• 

  Figure 11. Expression of Sirt3 in studied groups. Sirt3 immuno-stained heart tissue sections showed decreased immunoreactivity (brown colour) of Sirt3 marker in ISO group (B) compared to other groups. (F) Morphometrical analysis showing a decreased percentage of Sirt3 immunoreactivity in the ISO group. Scale bars 5A–5E = 50 µm.