Preventive Effect of Low Molecular Weight Glycosaminoglycan from Amussium pleuronectus (Linne) on Oxidative Injury and Cellular Abnormalities in Isoproterenol-Induced Cardiotoxicity in Wistar Rats

Early Aerobic Exercise Combined with Hydrogen-Rich Saline as Preconditioning Protects Myocardial Injury Induced by Acute Myocardial Infarction in Rats

It has been reported that hydrogen-rich saline (HRS) water reduces oxidative stress, and early aerobic exercise (eAE) acts an efficient exercise preconditioning (EP) against cardiac I/R injury. However, whether early aerobic exercise combined with hydrogen-rich saline (eAE-HRS) water can more effectively protect myocardial damage induced by acute myocardial infarction (MI) is still unknown. This study was aimed to evaluate the effect of eAE-HRS in preventing MI-induced myocardial damage and explore the possible underlying mechanisms. After Sprague-Dawley (SD) rats were given a intragastric administration of HRS (1.6 ppm) at a dosage of 10 mL/kg weight daily for 3 weeks and/or the SD rats were performed a eAE program with 3 weeks running training, the left anterior descending coronary artery was ligated to induce MI. We assessed the effects of eAE-HRS on myocardial injury and oxidative damage in the MI model of rats and detected the effects of eAE-HRS on the expressions of cardiac OGG1 and Tom40, Tom20, and Tim23. The eAE-HRS increased significantly left ventricular systolic pressure, reduced left ventricular end-diastolic pressure, and potentiated + dp/dt_max, -dp/dt_max, heart coefficient and pH after MI injury. The eAE-HRS reduced MI-induced CK-MB level, c-Tnl level, h-FABP level, infarct size. The eAE-HRS enhanced MI-induced levels of the superoxide dismutase and total antioxidant capacity, attenuated MI-induced levels of malondialdehyde and catalase. The eAE-HRS increased expressions of OGG1, Tom20 and Tim23 proteins after MI injury, but not Tom40. The eAE-HRS has the potential to be a novel precautionary measure to protect myocardial injury after MI via partially regulating expressions of antioxidant-related proteins and mitochondrial-associated proteins.

Preventive effect of glycosaminoglycans from Amussium pleuronectus (Linne) on biomolecules, lactate dehydrogenase-isoenzyme and electrocardiographic patterns in isoproterenol-induced myocardial infarction in Wistar rats

Objectives:

This study was aimed to assess the cardioprotective role of low molecular weight glycosaminoglycans (LMW-GAG) in isoproterenol (ISO)-induced myocardial infarction (MI) in male Wistar rats. Effect of LMW-GAG on biomolecules, lactate dehydrogenase (LDH)-isoenzyme, and electrocardiographic (ECG)-patterns was studied as evidence of cardioprotection.

Materials and Methods:

Male Wistar rats (140 ± 10 g) were divided into four groups; untreated control (group I), LMW-GAG treated (300 μg/day s. c. for 2 weeks—group II), ISO (85 mg s.c. injected on 13^th and 14^th days—group III), and LMW-GAG plus ISO (300 μg/day s. c. for 12 days followed by 85 mg/kg ISO on the end of 13^th and 14^th days—group IV). At the end of the experimental period, all animals were terminated.

Results:

Rats treated with LMW-GAG (300 μg/kg) for 12 days showed significant increasing levels of triglyceride (TG) (both serum and heart tissue), low density lipoprotein (LDL), very low density lipoprotein (VLDL), total cholesterol, uric acid, creatinine, and glucose. However, it significantly decreased the levels of high density lipoprotein (HDL) (serum), plasma total protein, and albumin/globulin (A/G) ratio. ISO also adversely affected the LDH-isoenzymes and caused marked elevation in ST segment. Pretreatment with LMW-GAG (300 μg/kg) daily for a period of 2 weeks prevented the ISO-treated changes.

Conclusions:

The results indicate that LMW-GAG exhibits a cardioprotective effect in ISO-induced MI in rats, by maintaining the biomolecules and LDH-isoenzymes.

Chondroitin sulfate reduces cell death of rat hippocampal slices subjected to oxygen and glucose deprivation by inhibiting p38, NFκB and iNOS

The glycosaminoglycan chondroitin sulfate (CS) is a major constituent of the extracellular matrix of the central nervous system where it can constitute part of the perineuronal nets. Constituents of the perineuronal nets are gaining interest because they have modulatory actions on their neighbouring neurons. In this study we have investigated if CS could afford protection in an acute in vitro ischemia/reoxygenation model by using isolated hippocampal slices subjected to 60min oxygen and glucose deprivation (OGD) followed by 120min reoxygenation (OGD/Reox). In this toxicity model, CS afforded protection of rat hippocampal slices measured as a reduction of lactate dehydrogenase (LDH) release; maximum protection (70% reduction of LDH) was obtained at the concentration of 3mM. To evaluate the intracellular signaling pathways implicated in the protective effect of CS, we first analysed the participation of the mitogen-activated protein kinases (MAPKs) p38 and ERK1/2 by western blot. OGD/Reox induced the phosphorylation of p38 and dephosphorylation of ERK1/2; however, CS only inhibited p38 but had no effect on ERK1/2. Furthermore, OGD/Reox-induced translocation of p65 to the nucleus was prevented in CS treated hippocampal slices. Finally, CS inhibited iNOS induction caused by OGD/Reox and thereby nitric oxide (NO) production measured as a reduction in DAF-2 DA fluorescence. In conclusion, the protective effect of CS in hippocampal slices subjected to OGD/Reox can be related to a modulatory action of the local immune response by a mechanism that implies inhibition of p38, NFκB, iNOS and the production of NO.