Effect of Exercise Training and l-arginine on Oxidative Stress and Left Ventricular Function in the Post-ischemic Failing Rat Heart

Quercetin and L-Arginine Ameliorated the Deleterious Effects of Copper Oxide Nanoparticles on the Liver of Mice Through Anti-inflammatory and Anti-apoptotic Pathways

The widespread use and applications of copper oxide nanoparticles (CuO NPs) in daily life make human exposure to these particles inevitable. This study was carried out to investigate the deteriorations in hepatic and serum biochemical parameters induced by CuO NPs in adult male mice and the potential ameliorative effect of L-arginine and quercetin, either alone or in combination. Seventy adult male mice were equally allocated into seven groups: untreated group, L-arginine, quercetin, CuO NPs, arginine + CuO NPs, quercetin + CuO NPs, and quercetin + arginine + CuO NPs. Treating mice with CuO NPs resulted in bioaccumulation of copper in the liver and consequent liver injury as typified by elevation of serum ALT activity, reduction in the synthetic ability of the liver indicated by a decrease in the hepatic arginase activity, and serum total protein content. This copper accumulation increased oxidative stress, lipid peroxidation, inflammation, and apoptosis as manifested by elevation in malondialdehyde, nitric oxide, tumor necrosis factor-α, the expression level of caspase-3 and bax quantified by qPCR, and the activity of caspase-3, in addition to the reduction of superoxide dismutase activity. It also resulted in severe DNA fragmentation as assessed by Comet assay and significant pathological changes in the liver architecture. The study proved the efficiency of quercetin and L-arginine in mitigating CuO NPs-induced sub-chronic liver toxicity due to their antioxidant, anti-inflammatory, and anti-apoptotic properties; ability to inhibit DNA damage; and the potential as good metal chelators. The results of histopathological analysis confirmed the biochemical and molecular studies.

Loaded paraquaton polymeric nanocapsules and evaluation for cardiotoxicity in Wistar rats

Present work was conducted to prepare and evaluate, loaded paraquat nano-hydrogels using chitosan, sodium polytriphosphate, and xanthan via ionic gelification method. The fabricated L-PQ formulations were analyzed for surface morphology and functional groups using SEM and FTIR, respectively. The stability of the synthesized nanoparticle was, also, analyzed in terms of diameter size, zeta potential, dispersion index, and pH. Furthermore, the cardiotoxicity effects of the synthesized nanogels were investigated on Wistar rats in terms of enzymatic activity, echocardiographic, and histological analysis. The proper stability of the prepared formulation was also confirmed by diameter size, zeta potential, dispersion index, and pH. The efficiency of encapsulation was about 90±3.2% and the release of PQ in the loaded nanogel was about 90±2.3%. A decrease in ST (shortening time) segment by formulated PQ, either in peritoneal or gavage exposure pathway, indicates the effectiveness of the capsule layer against the penetration of toxin into the body.

MOTS-c and Exercise Restore Cardiac Function by Activating of NRG1-ErbB Signaling in Diabetic Rats

Pathologic cardiac remodeling and dysfunction are the most common complications of type 2 diabetes. Physical exercise is important in inhibiting myocardial pathologic remodeling and restoring cardiac function in diabetes. The mitochondrial-derived peptide MOTS-c has exercise-like effects by improving insulin resistance, combatting hyperglycemia, and reducing lipid accumulation. We investigated the effects and transcriptomic profiling of MOTS-c and aerobic exercise on cardiac properties in a rat model of type 2 diabetes which was induced by feeding a high fat high sugar diet combined with an injection of a low dose of streptozotocin. Both aerobic exercise and MOTS-c treatment reduced abnormalities in cardiac structure and function. Transcriptomic function enrichment analysis revealed that MOTS-c had exercise-like effects on inflammation, myocardial apoptosis, angiogenesis and endothelial cell proliferation and migration, and showed that the NRG1-ErbB4 pathway might be an important component in both MOTS-c and exercise induced attenuation of cardiac dysfunction in diabetes. Moreover, our findings suggest that MOTS-c activates NRG1-ErbB4 signaling and mimics exercise-induced cardio-protection in diabetes.

Aerobic Training Associated with Arginine Supplementation Reduces Collagen-Induced Platelet Hyperaggregability in Rats under High Risk to Develop Metabolic Syndrome

BACKGROUND

Increased platelet response is seen in individuals with metabolic syndrome. Previous reports have shown that arginine supplementation and aerobic exercise training enhance vascular nitric oxide (NO) activity and inhibit platelet hyperaggregability; however, the effects of their association remain unknown.

AIM

To investigate whether arginine supplementation and aerobic exercise association may exert beneficial effects, reducing platelet hyperaggregability in rats under high risk to develop metabolic syndrome.

METHODS

Wistar rats were divided into two groups: control (C) and fructose (F - water with 10% of fructose). After two weeks, the F group was subdivided into four groups: F, the same as before; fructose + arginine (FA - 880 mg/kg/day of L-arginine by gavage); fructose + training (FT); and fructose + arginine + training (FTA). Treatment lasted for eight weeks.

RESULTS

The fructose administration was able to increase the collagen-induced platelet aggregation (27.4 ± 2.7%) when compared to the C group (8.0 ± 3.4%). Although the arginine supplementation (32.2 ± 6.3%) or aerobic training (23.8 ± 6.5%) did not promote any change in platelet collagen-induced hyperaggregability, the association of arginine supplementation and aerobic exercise promoted an inhibition of the platelet hyperaggregability induced by fructose administration (13.9 ± 4.4%) (P < 0.05). These effects were not observed when ADP was employed as an agonist. In addition, arginine supplementation associated with aerobic exercise promoted a decrease in interleukin-6 (IL-6) and interleukin-8 (IL-8) serum levels when compared to the fructose group, demonstrating an anti-inflammatory effect.

CONCLUSIONS

Our data indicate an important role of arginine supplementation associated with aerobic exercise, reducing platelet hyperaggregability and inflammatory biomarker levels in rats under high risk to develop metabolic syndrome.

Aerobic training and L-arginine supplement attenuates myocardial infarction-induced kidney and liver injury in rats via reduced oxidative stress

Introduction

The aim of the present study was to determine the effect of exercise training and l-arginine supplementation on kidney and liver injury in rats with myocardial infarction (MI).

Material and methods

Four weeks after MI, 50 male wistar rats randomly divided into five followed groups: sham surgery without MI (Sham, n = 10), Sedentary-MI (Sed-MI, n = 10) 3: L-Arginine-MI (La-MI, n = 10) 4: Exercise training-MI (Ex-MI, n = 10) and 5: Exercise and L-arginine-MI (Ex + La-MI). Ex-MI and Ex + La-MI groups running on a treadmill for 10 weeks with moderate intensity. Rats in the L-arginine-treated groups drank water containing 4% L-arginine. Tissues oxidative stress and kidney and liver functional indices were measured after treatments.

Result

Urea as a kidney function indexes, increased in Sed-MI group in compared to sham group and decreased significantly in Ex-MI and Ex + La-MI groups. The level of catalase (CAT) and glutathione stimulating hormone (GSH) of kidney were significantly lower in the MI-groups compared with the Sham group and kidney Malondialdehyde (MDA) levels increased after MI and significantly decreased in response to aerobic training and L-arginine. As well as, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) as liver injury indices, increased in MI-groups and decreased by training and L-arginine. In this regards, liver MDA and CAT respectively increased and decreased in MI-groups, but aerobic training and L-arginine increased liver glutathione per-oxidase (GPx) and decreased liver MDA.

Conclusion

These results demonstrated that kidney and liver function impaired 14 weeks after MI and aerobic training and L-arginine supplementation synergistically ameliorated kidneys and liver injury in myocardial infarction rats through oxidative stress reduction.

Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction

Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats.

Synergistic effects of nitric oxide and exercise on revascularisation in the infarcted ventricle in a murine model of myocardial infarction

It has been shown that density of microvessels decreases in the left ventricular after myocardial infarction (MI). The change of angiogenic and angiostatic factors as the main factors in revascularisation after exercise training in area at risk is not determined yet in MI. Therefore, the aim of the present study was the effect of exercise training and L-arginine supplementation on area at risk angiogenesis in myocardial infarction rat. Four weeks after surgery (Left Anterior Descending Coronary artery Ligation), myocardial infarction rats were divided into 4 groups: Sedentary rats (Sed-MI); L-arginine supplementation (La-MI); Exercise training (Ex-MI) and Exercise + L-arginine (Ex+La). Exercise training (ET) lasted for 10 weeks at 17 m/min for 10-50 min day(-1). Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. After ET and L-arginine supplementation, ventricular function was evaluated and angiogenic and angiostatic indices were measured at ~1 mm from the edge of scar tissue (area at risk). Statistical analysis revealed that gene expression of VEGF as an angiogenic factor, angiostatin as an angiostatic factor and caspase-3 at area at risk decrease significantly in response to exercise training compared to the sedentary group. The capillary and arteriolar density in the Ex groups were significantly higher than those of the Sed groups. Compared to the Ex-MI group, the Ex+La group showed a markedly increase in capillary to fiber ratio. No significant differences were found in infarct size among the four groups, but cardiac function increased in response to exercise. Exercise training increases revascularization at area at risk by reduction of angiostatin. L-arginine supplementation causes additional effects on exercise-induced angiogenesis by preventing more reduction of VEGF gene expression in response to exercise. These improvements, in turn, increase left ventricular systolic function and decrease mortality in myocardial infarction rats.

Investigation into the antioxidant role of arginine in the treatment and the protection for intralipid-induced non-alcoholic steatohepatitis

Background

This study investigated the possible roles of arginine (Arg) in ameliorating oxidative damage of intralipid (IL)-induced steatohepatitis (NASH).

Methods

NASH was induced in Sprague-Dawley rats by intravenous administration of 20 % IL for three weeks and then rats were pre- and post-treated with intraperitoneal injection of Arg for two weeks. Several biochemical parameters (blood and hepatic lipid peroxidation, glutathione, glutathione peroxidase and superoxide dismutase, hepatic cytochrome P450 2El monooxygenase (CYP2E1), nitric oxide (NO), endothelial nitric oxide synthase (eNOS) and tumor necrosis factor-α “TNF-α”) and liver histopathology were detected for rat groups.

Results

The administration of Arg either before or after IL significantly ameliorated uncontrolled elevation of TBARS content, CYP2E1 activity (0.32 ± 0.01 or 0.3 ± 0.02 IU/mg) and TNF-α level. These effects were associated with a significant increase in the levels of glutathione, activities of antioxidant enzymes, NO level (1.649 ± 0.047 or 1.957 ± 0.073 μmol/g) and activity of hepatic eNOS (0.05 ± 0.002 or 0.056 ± 0.002 IU/mg) compared to the IL-treated rats. Moreover, the injection of Arg in NASH-induced rats showed normal hepatocytes, no steatosis and no bile duct proliferation but mild inflammation in the group which received IL after Arg.

Conclusions

These results proved that pre- and post-treatment with Arg blocked oxidative stress-induced NASH by inhibiting CYP2E1 activity, decreasing TNF- α level and restoration activities of eNOS and antioxidant enzymes as well as glutathione level. This antioxidant effect of Arg leads to reverse signs of liver pathology of NASH with amelioration of liver and kidney functions.