Evaluating the potential effect of melatonin on the post-cardiac surgery sleep disorder

Postoperative neurological injuries, including cognitive dysfunction, sleep disorder, delirium, and anxiety, are the important consequences of coronary artery bypass graft surgery [CABG]. Evidence has shown that postoperative sleep disturbance is partly due to disturbed melatonin secretion in the perioperative period. The aim of this study was to evaluate the effect of melatonin on postoperative sleep disorder in patients undergoing CABG. One hundred forty-five elective CABG patients participated in a randomized double-blind study during the preoperative period. The patients were randomized to receive either 3 mg of melatonin or 10 mg of Oxazepam one hour before sleep time. Each group received the medication from 3 days before surgery until the time of discharge. Sleep quality was evaluated using the Groningen Sleep Quality Score [GSQS], and the incidence of delirium was evaluated by nursing records. Sleep quality and anxiety scores were compared before and after surgery through the Wilcoxon signed-rank test. The analysis of covariance [ANCOVA] and independent t-test were used to compare the sleep and anxiety scores between the groups. P values

Prolonged preconditioning with natural honey against myocardial infarction injuries

Potential protective effects of prolonged preconditioning with natural honey against myocardial infarction were investigated. Male Wistar rats were pre-treated with honey [1%, 2% and 4%] for 45 days then their hearts were isolated and mounted on a Langendorff apparatus and perfused with a modified Krebs-Henseleit solution during 30 min regional ischemia fallowed by 120 min reperfusion. Two important indexes of ischemia-induced damage [infarction size and arrhythmias] were determined by computerized planimetry and ECG analysis, respectively. Honey [1% and 2%] reduced infarct size from 23 +/- 3.1% [control] to 9.7 +/- 2.4 and 9.5 +/- 2.3%, respectively [P<0.001]. At the ischemia, honey [1%] significantly reduced [P<0.05] the number and duration of ventricular tachycardia [VT]. Honey [1% and 2%] also significantly decreased number of ventricular ectopic beats [VEBs]. In addition, incidence and duration of reversible ventricular fibrillation [Rev VF] were lowered by honey 2% [P<0.05]. During reperfusion, honey produced significant reduction in the incidences of VT, total and Rev VF, duration and number of VT. The results showed cardioprotective effects of prolonged pre-treatment of rats with honey following myocardial infarction. Maybe, the existence of antioxidants and energy sources [glucose and fructose] in honey composition and improvement of hemodynamic functions may involve in those protective effects

Effects of chronic oral administration of natural honey on ischemia/reperfusion-induced arrhythmias in isolated rat heart

In this study, effects of chronic administration of oral natural honey against ischemia/reperfusion [I/R]-induced cardiac arrhythmias were investigated in isolated rat heart. Male Wistar rats were divided into four groups [n= 10-14 rats in each group] and fed with natural honey [1%, 2% and 4% dissolved in the drinking water] for 45 days except for the control group. After anesthesia, the rats' hearts were isolated quickly, mounted on a Langendorff apparatus and perfused with a modified Krebs-Henseleit solution during stabilization, 30 min regional ischemia followed by 30 min reperfusion. The ECGs were recorded throughout the experiments to analyze cardiac arrhythmias based on the Lambeth conventions In the ischemic phase, honey [1%] significantly reduced [P<0.05] the number and duration of ventricular tachycardia [VT]. Honey [1% and 2%] also significantly decreased number of ventricular ectopic beats [VEBs]. In addition, incidence and duration of reversible ventricular fibrillation [Rev VF] were lowered by honey 2% [P<0.05]. During reperfusion time, VT incidence was 73% in the control group, however natural honey [1%] decreased it to 22% [P<0.05]. Honey also produced significant reduction in the incidences of total VF, Rev VF, duration and number of VT. For the first time, the results of present study demonstrated protective effects of chronic oral honey administration against I/R-induced arrhythmias in isolated rat heart. Antioxidant activity, the existence of energy sources such as glucose and fructose and improvement of some hemodynamic functions might be responsible for these effects

Effects of acetyl-L-carnitme on cardiac arrhythmias and infarct size in ischemic-reperfused isolated rat heart

This study aimed to examine whether acetyl-L-carnitine [ALC] was able to reduce cardiac arrhythmias and infarct size in the ischemic-reperfused isolated rat heart. The isolated hearts were mounted on a Langendorff apparatus then perfused by a modified Krebs-Henseleit solution during 30 min regional ischemia and 120 min reperfusion [control] or by enriched Krebs solution with 0.375, 0.75, 1.5 and 3 mM of ALC [treatment groups]. The ECGs were recorded and analyzed to determine cardiac arrhythmias. The infarct size was determined by using a computerized planimetry package. During ischemia, all used concentrations of ALC decreased number and duration of ventricular tachycardia [VT], total number of ventricular ectopic beats [VEBs] [P<0.01], incidence of total ventricular fibrillation [VF] and the time spent for reversible VF [P<0.05]. At the reperfusion phase, duration of VT, incidence of total VF and reversible VF were significantly lowered by ALC [P<0.05]. In addition, infarct size significantly was decreased in all treated groups. In the control group, the infarct size was 23 +/- 3.1%, however, ALC [0.375, 0.75 and 3 mM] reduced it to 8.7 +/- 2.3, 5.3 +/- 1.4, and 8 +/- 2.9%, respectively [P0.01]. Considering the results, it may be concluded that ALC has protective effects against cardiac ischemia- reperfusion [I/R] injuries by reduction of infarct size and arrhythmias in isolated rat heart. Among the potential cardioprotective mechanisms for ALC, increase in glucose oxidation and resulting reduced lactate production, reduction of toxic fatty acid metabolites and removing free radicals from the myocytes are more relevant