Cardiac Antioxidant Enzyme Activities Research Articles

Kolaviron attenuates cardiovascular injury in fructose-streptozotocin induced type-2 diabetic male rats by reducing oxidative stress, inflammation, and improving cardiovascular risk markers

The prevalence of cardiovascular disease among type-2 diabetic patients has become a source of major concern world over. This study explored the protective effect of kolaviron, a bioflavonoid, against oxidative cardiovascular injury in fructose- streptozotocin-induced type 2 diabetic male Sprague Dawley rats. After acclimatization, induction, and confirmation of type-2 diabetes, kolaviron was administered for 28days, after which the animals were anesthetized with Isofor and euthanized. Blood from each rat were collected, and blood samples were then centrifuged for serum and plasma. Cardiac troponin I (cTnI), creatine kinase myocardial band (CK-MB), Creatine phosphokinase (CK), and insulin levels were immediately determined in serum, while remaining samples (serum, plasma, and organs) were stored in the bio-freezer at − 80 °C and 10% formalin for enzyme-link immunosorbent assay (ELISA), biochemical, molecular, and histopathological studies. The results show that type-2 diabetes induction with fructose and streptozotocin led to increased blood glucose levels, decreased insulin levels and cardiac antioxidant enzyme activities, increased malondialdehyde levels, cardiac biomarkers and pro-inflammatory cytokines levels, resulted in abnormal lipid profile, increased blood pressure and angiotensin-converting enzyme (ACE) activity, and decreased plasma endothelial nitric oxide synthase (eNOS) concentration. The histopathological examination of the cardiac tissue revealed severe lesion, hypertrophy, and myofibrils degeneration. However, administration of kolaviron for 28days remarkably improved these conditions. Hence the result from the study validates the potency of kolaviron, and suggests it could serve as an alternative to existing remedy in ameliorating or protecting against cardiovascular injury in type-2 diabetes.

Cardioprotective Potential of Garlic Oil and Its Active Constituent, Diallyl Disulphide, in Presence of Carvedilol during Chronic Isoprenaline Injection-Mediated Myocardial Necrosis in Rats.

In isoprenaline (ISO)-induced myocardial infarcted rats, garlic oil (GO) and its main ingredient, diallyl disulfide (DADS), were examined for cardioprotective effects when used with carvedilol (CAR). GO, DADS and CAR were given to rats in their respective groups, either alone or together, with the addition of isoprenaline (3 mg/kg/day, subcutaneously) during the last 10 days of treatment. At the end of 14 days of treatment, blood samples were collected, the hearts were excised under anesthesia and weighed. Heart tissue homogenate was used to measure superoxide dismutase (SOD), catalase (CAT), and thiobarbituric acid reactive substances (TBARS). Furthermore, the serum activities of cardiac markers, including lactate dehydrogenase, creatine kinase, and cardiac troponin, were checked. Moreover, inflammatory markers including tumor necrosis factor alpha, interleukin one beta, interleukin six, and kappa bp65 subunit were assessed. Rats that received GO, DADS, and CAR exhibited a significant increase in the cardiac antioxidant enzyme activities with a simultaneous decrease in serum cardiac markers enzymes and inflammatory markers. The TBARS were significantly reduced in rats that received treatment. The addition of carvedilol to GO or DADS significantly elevated antioxidant activities and decreased the release of cardiac enzymes into blood circulation. Both DADS and GOl were almost similar in efficacy, indicating the potential role of DADS in garlic oil-mediated cardioprotection. Combining GO or DADS with CAR increased CAR’s cardioprotective impact and protected rats from developing ISO-induced myocardial infarction.

Toxicity Reduction and Efficacy Promotion of Doxorubicin in the Treatment of Breast Tumors Assisted by Enhanced Oral Absorption of Curcumin-Loaded Lipid-Polyester Mixed Nanoparticles.

Curcumin (CUR), a polyphenol derived from turmeric, exhibits anticancer and anti-inflammatory properties. However, it has poor water solubility, stability, and oral bioavailability. To overcome these limitations, lipid-polyester mixed nanoparticles (NPs) embedded in enteric polymer-EudragitL100-55(Eu) were formulated (CUR-NPs-Eu). NPs composed of mPEG-b-PCL have a hybrid core made up of middle chain triglyceride (MCT) and poly(ε-caprolactone) (PCL) for enhancing drug loading. The CUR-NPs with MCT content of 10% had a particle size of 121.2 ± 16.8 nm, ζ potential of -16.25 ± 1.38 mV, drug loading of 9.8%, and encapsulation efficiency of 87.4%. The transport of the CUR-NPs-Eu across Caco-2 monolayers is enhanced compared with CUR alone (1.98 ± 0.94 × 10-6 of curcumin versus 55.43 ± 6.06 × 10-6 cm/s of curcumin-loaded NPs) because of the non-disassociated nanostructure during absorption. The absolute bioavailability of CUR-NPs-Eu was 7.14%, which was drastically improved from 1.08% of the CUR suspension (CUR-Sus). Therefore, in the xenograft 4T1 tumor-bearing mice, increased drug accumulation in heart and tumor was noticed because of enhanced oral bioavailability of CUR. The chemosensitizing effect of CUR was attributed to its NF-κB reduction effect (148 ± 11.83 of DOX alone versus 104 ± 8.71 of combined therapy, ng/g tissue). The cardioprotective effect of CUR was associated with maintenance of cardiac antioxidant enzyme activity and down-regulation of NF-κB. This study provided a partial illustration of the mechanisms of chemosensitizing and cardioprotective effects of CUR utilizing the oral availability promotion effect brought by the NPs-Eu formulation. And these results further demonstrated that the capability of this NPs-Eu system in oral delivery of poorly soluble and poorly permeable drugs.

Thermal tolerance and fish heart integrity: fatty acids profiles as predictors of species resilience.

The cardiovascular system is a major limiting system in thermal adaptation, but the exact physiological mechanisms underlying responses to thermal stress are still not completely understood. Recent studies have uncovered the possible role of reactive oxygen species production rates of heart mitochondria in determining species' upper thermal limits. The present study examines the relationship between individual response to a thermal challenge test (CTmax), susceptibility to peroxidation of membrane lipids, heart fatty acid profiles and cardiac antioxidant enzyme activities in two salmonid species from different thermal habitats (Salvelinus alpinus, Salvelinus fontinalis) and their hybrids. The susceptibility to peroxidation of membranes in the heart was negatively correlated with individual thermal tolerance. The same relationship was found for arachidonic and eicosapentaenoic acid. Total H2O2 buffering activity of the heart muscle was higher for the group with high thermal resistance. These findings underline a potential general causative relationship between sensitivity to oxidative stress, specific fatty acids, antioxidant activity in the cardiac muscle and thermal tolerance in fish and likely other ectotherms. Heart fatty acid profile could be indicative of species resilience to global change, and more importantly the plasticity of this trait could predict the adaptability of fish species or populations to changes in environmental temperature.

Late‐In‐Life Treadmill‐Training Ameliorates the Decline in Cardiac Autophagy Associated with Aging in Mice

Protein aggregates accumulate and organelles become damaged and/or dysfunctional during the process of aging. A progressive loss of the cellular quality control mechanism autophagy contributes to this age‐associated decline in cellular function in many organs. Evidence for an age‐associated repression in cardiac autophagy is not consistent. We hypothesized that 24‐month old (old) male C57Bl6/J mice exhibit repressed autophagosome formation in the heart, myocardial dysfunction, and reduced exercise capacity vs. 6‐month old (adult) mice. First, cardiac lysates from old mice displayed reduced (p<0.05) accumulation of LC3II/GAPDH and degradation of p62 vs. adult animals (n=12 per group). Second, the lysosomal acidification inhibitor chloroquine (CQ) induced accrual (p<0.05) of LC3II/GAPDH and p62 in hearts from adult but not old mice (n=7 per group). Third, left ventricular mass was greater (p<0.05), and indices of systolic, diastolic, and global left ventricular function (transthoracic echocardiography) were impaired, in old vs. adult animals (n=12 per group). Finally, maximal workload performed during a treadmill‐test was less (p<0.05) in aged (n=11) vs. adult (n=12) mice. To determine whether late‐in‐life exercise training induces cardiac autophagy, separate cohorts of male mice completed a progressive‐resistance treadmill‐running program (old‐ETR) or remained sedentary (old‐SED) from 21–24 months. Body composition, exercise performance during a maximal workload test, soleus muscle citrate synthase (CS) activity, indices of cardiac antioxidant enzyme activity, markers of cardiac autophagy, and indices of myocardial function, all improved (p<0.05) in old‐ETR (n=11) vs. old‐SED (n=12) mice. These data are the first to demonstrate that markers of cardiac autophagy are elevated, and indices of myocardial function are improved, in old mice that complete a treadmill‐training regimen that is sufficient to increase skeletal muscle CS activity and maximal exercise capacity. These data provide strong proof of concept to evaluate cause and effect relationships among exercise‐training, myocardial.Support or Funding InformationUU Research Fellowship (JMC); APS UGRF (CR); AHA17POST33670663 (SKP); NIHRO1DK098646‐01A1, NIHRO1DK099110, AHA16GRANT30990018 (SB); AHA16GRNT31050004, NIH RO3AGO52848, NIH RO1HL141540 (JDS).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

STUDY OF THE PROBABLE AMELIORATIVE EFFECT OF CROCIN ON MONOSODIUM GLUTAMATE-INDUCED CARDIOTOXICITY IN MALE ALBINO RATS

Monosodium glutamate (MSG) is a flavor enhancer used widely in modern nutrition. The current research aimed at studying the protective effect of Crocin, the main constituent of Crocus sativus L., on MSG-induced cardiotoxicity on male albino rats. The study was performed on 50 adult male albino rats randomly and equally divided into five groups: negative control, vehicle control (received 1 ml saline/day), crocin group (treated with 20 mg/Kg/day crocin dissolved in 1 ml saline), MSG group (received 3 g/Kg/day MSG dissolved in 1 ml saline) and MSG + crocin (treated with MSG and crocin in the same previously mentioned doses). All treatments were gavaged orally once daily for 8 weeks. The results showed that MSG exposure significantly increased total body weight and relative heart weight, serum interleukin (IL)-1β, creatine kinase-myocardial band (CK-MB), Troponin I (CTnI). Also, MSG exposure significantly decreased serum level of IL-10. Cardiac oxidative stress parameters showed elevated malonedialdehyde (MDA) levels, decreased reduced glutathione (GSH) content and depressed cardiac antioxidant enzyme activities. 8- hydroxy-2-deoxyguanosine (8-OHdG) was increased significantly in comparison to the control groups. And there was significant increase in caspase-3 gene expression. These results were supported by histological and immune-histochemical alterations in the heart of MSG-treated rats. Notably, all these changes were partially ameliorated in rats treated concomitantly with MSG and crocin. The results of the present study showed that crocin exerts protective effects against MSG-induced cardiotoxicity in rats.

Effects of Fenugreek Seed Extract and Swimming Endurance Training on Plasma Glucose and Cardiac Antioxidant Enzymes Activity in Streptozotocin-induced Diabetic Rats

ObjectiveDiabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia condition resulting from defective insulin secretion or resistance insulin action, or both. The purpose of this study was to evaluate the effect of 6 weeks swimming training and Trigonella foenum-graecum seed (fenugreek) extract, alone and in combination, on plasma glucose and cardiac antioxidant enzyme activity of streptozotocin-induced diabetic rats. MethodsFifty male Wistar rats were divided into five groups: diabetic control (DC, n = 8); healthy control (HC, n = 11); swimming training (S, n = 11); swimming training + fenugreek seed extract (1.74 g/kg body weight; SF1, n = 11); and swimming training + fenugreek seed extract (0.87 g/kg body weight; SF2, n = 9). Streptozotocin was used for the induction of diabetes. Results were analyzed using one-way analysis of variance followed by Tukey test. ResultsIn comparison with the DC group, all groups exhibited a significant decrease in body weight (p < 0.05), except for the HC group. SF1 and HC groups showed significant decreases in plasma glucose levels compared with the DC group (p < 0.05). S, SF1, SF2, and HC groups showed significant elevations in cardiac antioxidant enzymes activity in comparison with the DC group. ConclusionThe results indicated that the combination of endurance swimming training and fenugreek seed extract can significantly reduce the plasma glucose levels and increase cardiac antioxidant enzymes activity in diabetic rats. Our findings suggest that this combination could be useful for the treatment of hyperglycemia and cardiac oxidative stress induced by diabetes mellitus.

Protection from Oxidative and Electrophilic Stress in the Gsta4-null Mouse Heart

4-Hydroxynonenal (4-HNE) mediates many pathological effects of oxidative and electrophilic stress and signals to activate cytoprotective gene expression regulated by NF-E2-related factor 2 (Nrf2). By exhibiting very high levels of 4-HNE-conjugating activity, the murine glutathione transferase alpha 4 (GSTA4-4) helps regulate cellular 4-HNE levels. To examine the role of 4-HNE in vivo, we disrupted the murine Gsta4 gene. Gsta4-null mice exhibited no cardiac phenotype under normal conditions and no difference in cardiac 4-HNE level as compared to wild-type mice. We hypothesized that the Nrf2 pathway might contribute an important compensatory mechanism to remove excess cardiac 4-HNE in Gsta4-null mice. Cardiac nuclear extracts from Gsta4-null mice exhibited significantly higher Nrf2 binding to antioxidant response elements. We also observed responses in critical Nrf2 target gene products: elevated Sod2, Cat, and Akr1b7 mRNA levels and significant increases in both cardiac antioxidant and anti-electrophile enzyme activities. Gsta4-null mice were less sensitive and maintained normal cardiac function following chronic doxorubicin treatment, known to increase cardiac 4-HNE levels. Hence, in the absence of GSTA4-4 to modulate both physiological and pathological 4-HNE levels, the adaptive Nrf2 pathway may be primed to contribute to a preconditioned cardiac phenotype in the Gsta4-null mouse.

AT1 blockade decreases NADPH oxidase 2 content and increases insulin signaling in a model of insulin resistance

Angiotensin II (Ang II) increases oxidant production through the activation of Nox2 during insulin resistance (IR). Angiotensin receptor blockers (ARB) improve IR in the peripheral tissue suggesting a link among Ang II receptor (AT1) activation, oxidative stress and development of IR; however, these relationships in the heart are not well described. To test the hypothesis that AT1 activation increases NADPH oxidase (Nox) content and oxidative damage, while impairing insulin signaling and antioxidant enzyme activities, we measured Nox2 and 4, insulin signaling proteins, oxidative damage and antioxidant enzyme activity in the heart of OLETF rats, a model of insulin resistance. After 6 wks of treatment, hearts were collected from 3 groups of rats: 1) lean‐strain controls (LETO), 2) OLETF (15 wks of age), and 3) OLETF + ARB. ARB treatment increased Akt (57%) and AMPK (27%) activation in the OLETF rats, as well as, recovery in the p85α and Glut4 content. Similarly, AT1 blockade decreased (33%) Nox2 content, and increased (36%) Nox4, associated with increased catalase (41%) and SOD (70%) activities. The results suggest that Nox2 activity is dependent on AT1 activation and promotes oxidative damage. Furthermore, the parallel increases in Nox4 and antioxidant enzyme activities in the heart suggest that Nox4 activation is important for signaling cardiac antioxidant enzyme activities to abate the Nox2‐induced damage.

One-Month Diesel Exhaust Inhalation Produces Hypertensive Gene Expression Pattern in Healthy Rats

BackgroundExposure to diesel exhaust (DE) is linked to vasoconstriction, endothelial dysfunction, and myocardial ischemia in compromised individuals.ObjectiveWe hypothesized that DE inhalation would cause greater inflammation, hematologic alterations, and cardiac molecular impairment in spontaneously hypertensive (SH) rats than in healthy Wistar Kyoto (WKY) rats.Methods and resultsMale rats (12–14 weeks of age) were exposed to air or DE from a 30-kW Deutz engine at 500 or 2,000 μg/m3, 4 hr/day, 5 days/week for 4 weeks. Neutrophilic influx was noted in the lung lavage fluid of both strains, but injury markers were minimally changed. Particle-laden macrophages were apparent histologically in DE-exposed rats. Lower baseline cardiac anti-oxidant enzyme activities were present in SH than in WKY rats; however, no DE effects were noted. Cardiac mitochondrial aconitase activity decreased after DE exposure in both strains. Electron microscopy indicated abnormalities in cardiac mitochondria of control SH but no DE effects. Gene expression profiling demonstrated alterations in 377 genes by DE in WKY but none in SH rats. The direction of DE-induced changes in WKY mimicked expression pattern of control SH rats without DE. Most genes affected by DE were down-regulated in WKY. The same genes were down-regulated in SH without DE producing a hypertensive-like expression pattern. The down-regulated genes included those that regulate compensatory response, matrix metabolism, mitochondrial function, and oxidative stress response. No up-regulation of inflammatory genes was noted.ConclusionsWe provide the evidence that DE inhalation produces a hypertensive-like cardiac gene expression pattern associated with mitochondrial oxidative stress in healthy rats.

Hypolipidaemic and Antioxidant Activity of Diallyl Disulphide in Rats

The efficacy of diallyl disulphide (DADS), a constituent of garlic oil, as a hypolipidaemic and antioxidant agent was evaluated in rats. In normolipidaemic rats DADS, at doses ranging from 10 to 50 mg kg−1, decreased plasma triglyceride without affecting cholesterolaemia and fast-or noradrenaline-induced lipolysis. DADS proved effective in reducing fructose-induced hypertriglyceridaemia and dietary hypercholesterolaemia in rats, in the latter model DADS significantly raised both the HDL cholesterol and the HDL/VLDL + LDL cholesterol ratio. DADS proved ineffective on triton induced hyperlipidaemia. To gain insight into the antioxidant effect of DADS, hepatic and cardiac antioxidant enzyme activity and glutathione content were studied in rats fed on a high diet and DADS. The antioxidant enzyme activity was significantly enhanced whereas glutathione content was markedly restored in rats fed on a high fat diet simultaneously with DADS. Thus, it appears that DADS exert antioxidant protection by activating the associated antioxidant enzymes.

Effects of copper deficiency on hepatic and cardiac antioxidant enzyme activities in lactose- and sucrose-fed rats

1. A number of dietary sugars are known to mediate the effects of copper deficiency. The effects of lactose (compared with sucrose) and a dietary Cu deficiency on hepatic and cardiac antioxidant enzyme activities and tissue mineral element status were investigated in the rat. 2. Groups (n 6) of male weanling Wistar rats were provided ad lib. with deionized water and diets containing sucrose (580 g/kg) or sucrose and lactose (387 g/kg and 193 g/kg respectively) with either control (12.0 mg/kg) or deficient (1.5 mg/kg) quantities of Cu for 77 d. 3. Animals consuming the low-Cu diets exhibited significantly decreased tissue Cu levels (P less than 0.01), hepatic and cardiac cytochrome c oxidase (EC 1.9.3.1, CCO) activities (P less than 0.01 and P less than 0.001 respectively) and hepatic Cu-zinc superoxide dismutase (EC 1.15.1.1, CuZnSOD) activity (P less than 0.05). The low-Cu diets also significantly decreased cardiac manganese superoxide dismutase (EC 1.15.1.1, MnSOD), catalase (EC 1.11.1.6) and glutathione peroxidase (EC 1.11.1.9, GSH-Px) activities (P less than 0.01, P less than 0.05 and P less than 0.001 respectively). 4. Hepatic Mn was significantly increased in both lactose-fed (P less than 0.001) and Cu-deficient (P less than 0.01) animals. These increases were unrelated to hepatic MnSOD activity. Cardiac Zn was significantly (P less than 0.01) increased in Cu-deficient animals. 5. Lactose feeding resulted in significantly increased cardiac CCO activity (P less than 0.001) but significantly decreased hepatic CuZnSOD (P less than 0.05), catalase (P less than 0.01) and GSH-Px (P less than 0.001) activities. 6. The activities of lactose dehydrogenase (EC 1.1.1.27, LDH) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49, G6PDH) were found to be significantly (P less than 0.05 and P less than 0.01 respectively) increased in Cu-deficient animals and G6PDH activity was significantly (P less than 0.01) decreased as a result of lactose consumption. 7. The observed changes in antioxidant enzyme activities associated with both Cu deficieny and lactose consumption may have important implications for the development of free radical mediated cell damage. However, no significant differences in either hepatic or cardiac levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation, were found.