Klotho protects the heart from hyperglycemia-induced injury by inactivating ROS and NF-κB-mediated inflammation both in vitro and in vivo

Cardiac inflammation and oxidative stress play a key role in the pathogenesis of diabetic cardiomyopathy (DCM). The anti-aging protein Klotho has been found to protect cells from inflammation and oxidative stress. The current study aimed to explore the cardioprotective effects of Klotho on DCM and the underlying mechanisms. H9c2 cells and neonatal cardiomyocytes were incubated with 33 mM glucose in the presence or absence of Klotho. Klotho pretreatment effectively inhibited high glucose-induced inflammation, ROS generation, apoptosis, mitochondrial dysfunction, fibrosis and hypertrophy in both H9c2 cells and neonatal cardiomyocytes. In STZ-induced type 1 diabetic mice, intraperitoneal injection of Klotho at 0.01 mg/kg per 48 h for 3 months completely suppressed cardiac inflammatory cytokines and oxidative stress and prevented cardiac cell death and remodeling, which subsequently improved cardiac dysfunction without affecting hyperglycemia. This study revealed that Klotho may exert its protective effects by augmenting nuclear factor erythroid 2-related factor 2 (Nrf2) expression and inactivating nuclear factor κB (NF-κB) activation both in vitro and in vivo. Thus, this work demonstrated for the first time that the anti-aging protein Klotho may be a potential therapeutic agent to treat DCM by inhibiting oxidative stress and inflammation. We also demonstrated the critical roles of the Nrf2 and NF-κB pathways in diabetes-stimulated cardiac injuries and indicated that they may be key therapeutic targets for diabetic complications.     

β1-Adrenergic blockers exert antioxidant effects,reduce matrix metalloproteinase activity,and improve renovascular hypertension-induced cardiac hypertrophy

Hypertension induces left-ventricular hypertrophy (LVH) by mechanisms involving oxidative stress and unbalanced cardiac matrix metalloproteinase (MMP) activity. We hypothesized that β₁-adrenergic receptor blockers with antioxidant properties (nebivolol) could reverse hypertension-induced LVH more effectively than conventional β₁-blockers (metoprolol) when used at doses that exert similar antihypertensive effects. Two-kidney one-clip (2K1C) hypertension was induced in male Wistar rats. Six weeks after surgery, hypertensive and sham rats were treated with nebivolol (10 mg kg⁻¹ day⁻¹) or metoprolol (20 mg kg⁻¹ day⁻¹) for 4 weeks. Systolic blood pressure was monitored weekly by tail-cuff plethysmography. LV structural changes and fibrosis were studied in hematoxylin/eosin- and picrosirius-stained sections, respectively. Cardiac MMP levels and activity were determined by in situ zymography, gel zymography, and immunofluorescence. Dihydroethidium and lucigenin-derived chemiluminescence assays were used to assess cardiac reactive oxygen species (ROS) production. Nitrotyrosine levels were determined in LV samples by immunohistochemistry and green fluorescence and were evaluated using the ImageJ software. Cardiac protein kinase B/Akt (AKT) phosphorylation state was assessed by Western blot. Both β-blockers exerted similar antihypertensive effects and attenuated hypertension-induced cardiac remodeling. Both drugs reduced myocyte hypertrophy and collagen deposition in 2K1C rats. These effects were associated with lower cardiac ROS and nitrotyrosine levels and attenuation of hypertension-induced increases in cardiac MMP-2 levels and in situ gelatinolytic activity after treatment with both β-blockers. Whereas hypertension increased AKT phosphorylation, no effects were found with β-blockers. In conclusion, we found evidence that two β₁-blockers with different properties attenuate hypertension-induced LV hypertrophy and cardiac collagen deposition in association with significant cardiac antioxidant effects and MMP-2 downregulation, thus suggesting a critical role for β₁-adrenergic receptors in mediating those effects. Nebivolol is not superior to metoprolol, at least with respect to their capacity to reverse hypertension-induced LVH.     

Enhanced ROS production by NADPH oxidase is correlated to changes in antioxidant enzyme activity in human heart failure

In pathological conditions, the balance between reactive oxygen species (ROS) and antioxidants may shift toward a relative increase of ROS, resulting in oxidative stress. Conflicting data are available on antioxidant defenses in human failing heart and they are limited to the left ventricle. Thus, we aimed to investigate and compare the source of oxidant and antioxidant enzyme activities in the right (RV) and left (LV) ventricles of human failing hearts. We found a significant increase in superoxide production only by NADPH oxidase in both failing ventricles, more marked in RV. Despite unchanged mRNA or protein expression, catalase (CAT) and glutathione peroxidase (GPx) activities were increased, and their increases reflected the levels of Tyr phosphorylation of the respective enzyme. Manganese superoxide dismutase (Mn-SOD) activity appeared unchanged. The increase in NADPH oxidase-dependent superoxide production positively correlated with the activation of both CAT and GPx. However, the slope of the linear correlation (m) was steeper in LV than in RV for GPx (LV: m = 2.416; RV: m = 1.485) and CAT (LV: m = 1.007; RV: m = 0.354). Accordingly, malondialdehyde levels, an indirect index of oxidative stress, were significantly higher in the RV than LV. We conclude that in human failing RV and LV, oxidative stress is associated with activation of antioxidant enzyme activity. This activation is likely due to post-translational modifications and more evident in LV. Overall, these findings suggest a reduced protection of RV against oxidative stress and its potential contribution to the progression toward overt heart failure.     

Kolaviron,a biflavonoid complex of Garcinia kola seeds modulates apoptosis by suppressing oxidative stress and inflammation in diabetes-induced nephrotoxic rats

Diabetic nephropathy is a complex disease that involves increased production of free radicals which is a strong stimulus for the release of pro-inflammatory factors. We evaluated the renal protective effect of kolaviron (KV) – a Garcinia kola seed extract containing a mixture of 5 flavonoids, in diabetes-induced nephrotoxic rats. Male Wistar rats were divided into 4 groups: untreated controls (C); normal rats treated with kolaviron (C + KV); untreated diabetic rats (D); kolaviron treated diabetic rats (D + KV). A single intraperitoneal injection of streptozotocin (STZ, 50 mg/kg) was used for the induction of diabetes. Renal function parameters were estimated in a clinical chemistry analyzer. Markers of oxidative stress in the kidney homogenate were analyzed in a Multiskan Spectrum plate reader and Bio-plex Promagnetic bead-based assays was used for the analysis of inflammatory markers. The effect of kolaviron on diabetes-induced apoptosis was assessed by TUNEL assay. In the diabetic rats, alterations in antioxidant defenses such as an increase in lipid peroxidation, glutathione peroxidase (GPX) activity and a decrease in catalase (CAT) activity, glutathione (GSH) levels and oxygen radical absorbance capacity (ORAC) were observed. There was no difference in superoxide dismutase (SOD) activity. Diabetes induction increased apoptotic cell death and the levels of interleukin (IL)-1β and tumor necrosis factor (TNF)-α with no effect on IL-10. Kolaviron treatment of diabetic rats restored the activities of antioxidant enzymes, reduced lipid peroxidation and increased ORAC and GSH concentration in renal tissues. Kolaviron treatment of diabetic rats also suppressed renal IL-1β. The beneficial effects of kolaviron on diabetes-induced kidney injury may be due to its inhibitory action on oxidative stress, IL-1β production and apoptosis.     

Dietary fatty acids and oxidative stress in the heart mitochondria

Our study compared the effects of different oils on oxidative stress in rat heart mitochondria, as well as on plasma parameters used as risk factors for cardiovascular disease. The rats were fed for 16 weeks with coconut, olive, or fish oil diet (saturated, monounsaturated, or polyunsaturated fatty acids, respectively). The cardiac mitochondria from rats fed with coconut oil showed the lowest concentration of oxidized proteins and peroxidized lipids. The fish oil diet leads to the highest oxidative stress in cardiac mitochondria, an effect that could be partly prevented by the antioxidant probucol. Total and LDL cholesterols decreased in plasma of rats fed fish oil, compared to olive and coconut oils fed rats. A diet enriched in saturated fatty acids offers strong advantages for the protection against oxidative stress in heart mitochondria.     

Indoxyl sulfate promotes cardiac fibrosis with enhanced oxidative stress in hypertensive rats

AimsCardiovascular disease (CVD) is common in chronic kidney disease (CKD) patients. Indoxyl sulfate (IS) is a nephrovascular uremic toxin that induces oxidative stress in kidney and vascular system. The present study aimed to examine the effect of IS on fibrosis and oxidative stress in rat heart.Main methodsThe effects of IS on heart were examined by Masson's trichrome (MT) staining and immunohistochemistry using: (1) Dahl salt-resistant normotensive rats (DN), (2) Dahl salt-resistant normotensive IS-administered rats (DN + IS), (3) Dahl salt-sensitive hypertensive rats (DH), and (4) Dahl salt-sensitive hypertensive IS-administered rats (DH + IS).Key findingsDH + IS rats showed significantly increased heart weight and left ventricle weight compared with DN. DH and DH + IS rats showed significantly increased diameter of cardiomyocytes, increased MT-positive fibrotic area, increased staining for transforming growth factor (TGF)-β1, α-smooth muscle actin (SMA), type 1 collagen, NADPH oxidase Nox 4, malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) and decreased staining for nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1) in the heart compared with DN. More notably, DH + IS rats showed significantly increased diameter of cardiomyocytes, increased fibrotic area, increased staining for TGF-β1, SMA, type 1 collagen, Nox4, 8-OHdG and MDA, and decreased staining for Nrf2 and HO-1 in the heart compared with DH.SignificanceIS aggravates cardiac fibrosis and cardiomyocyte hypertrophy with enhanced oxidative stress and reduced anti-oxidative defense in hypertensive rats.     

Protective role of CoQ10 or L-carnitine on the integrity of the myocardium in doxorubicin induced toxicity

Doxorubicin (DOX) is a chemotherapeutic agent used for treatment of different cancers and its clinical usage is hindered by the oxidative injury-related cardiotoxicity. This work aims to declare if the harmful effects of DOX on heart can be alleviated with the use of Coenzyme Q10 (CoQ10) or L-carnitine. The study was performed on seventy two female Wistar albino rats divided into six groups, 12 animals each: Control group; DOX group (10 mg/kg); CoQ10 group (200 mg/kg); L-carnitine group (100 mg/kg); DOX + CoQ10 group; DOX + L-carnitine group. CoQ10 and L-carnitine treatment orally started 5 days before a single dose of 10 mg/kg DOX that injected intraperitoneally (IP) then the treatment continued for 10 days. At the end of the study, serum biochemical parameters of cardiac damage, oxidative stress indices, and histopathological changes were investigated. CoQ10 or L-carnitine showed a noticeable effects in improving cardiac functions evidenced reducing serum enzymes as serum interleukin-1 beta (IL-1 β), tumor necrosis factor alpha (TNF-α), leptin, lactate dehydrogenase (LDH), Cardiotrophin-1, Troponin-I and Troponin-T. Also, alleviate oxidative stress, decrease of cardiac Malondialdehyde (MDA), Nitric oxide (NO) and restoring cardiac reduced glutathione levels to normal levels. Both corrected the cardiac alterations histologically and ultrastructurally. With a visible improvements in α-SMA, vimentin and eNOS immunohistochemical markers. CoQ10 or L-carnitine supplementation improves the functional and structural integrity of the myocardium.     

Chromium picolinate attenuates hyperglycemia-induced oxidative stress in streptozotocin-induced diabetic rats

Chromium picolinate is advocated as an anti-diabetic agent for impaired glycemic control. It is a transition metal that exists in various oxidation states and may thereby act as a pro-oxidant. The present study has been designed to examine the effect of chromium picolinate supplementation on hyperglycemia-induced oxidative stress. Diabetes was induced in male Wistar rats by a single intraperitoneal injection of streptozotocin (50 mg/kg body weight) and chromium was administered orally as chromium picolinate (1 mg/kg body weight) daily for a period of four weeks after the induction of diabetes. As is characteristic of diabetic condition, hyperglycemia was associated with an increase in oxidative stress in liver in terms of increased lipid peroxidation and decreased glutathione levels. The activity of antioxidant enzymes like superoxide dismutase, catalase and glutathione reductase were significantly reduced in liver of diabetic animals. Levels of α-tocopherol and ascorbic acid were found to be considerably lower in plasma of diabetic rats. Chromium picolinate administration on the other hand was found to have beneficial effect in normalizing glucose levels, lipid peroxidation and antioxidant status. The results from the present study demonstrate potential of chromium picolinate to attenuate hyperglycemia-induced oxidative stress in experimental diabetes.     

Selective inhibition of monoamine oxidase A by purpurin,an anthraquinone

Monoamine oxidase (MAO) catalyzes the oxidation of monoamines that act as neurotransmitters. During a target-based screening of natural products using two isoforms of recombinant human MAO-A and MAO-B, purpurin (an anthraquinone derivative) was found to potently and selectively inhibit MAO-A, with an IC₅₀ value of 2.50 μM, and not to inhibit MAO-B. Alizarin (also an anthraquinone) inhibited MAO-A less potently with an IC₅₀ value of 30.1 μM. Furthermore, purpurin was a reversible and competitive inhibitor of MAO-A with a K_i value of 0.422 μM. A comparison of their chemical structures suggested the 4-hydroxy group of purpurin might play an important role in its inhibition of MAO-A. Molecular docking simulation showed that the binding affinity of purpurin for MAO-A (?40.0 kcal/mol) was higher than its affinity for MAO-B (?33.9 kcal/mol), and that Ile 207 and Gly 443 of MAO-A were key residues for hydrogen bonding with purpurin. The findings of this study suggest purpurin is a potent, selective, reversible inhibitor of MAO-A, and that it be considered a new potential lead compound for development of novel reversible inhibitors of MAO-A (RIMAs).     

The cardioprotective effect of an aqueous extract of fermented rooibos (Aspalathus linearis) on cultured cardiomyocytes derived from diabetic rats

Diabetic cardiomyopathy (DCM) is a disorder of the heart muscle that contributes to cardiovascular deaths in the diabetic population. Excessive generation of free radicals has been directly implicated in the pathogenesis of DCM. The use of antioxidants, through dietary supplementation, to combat increased cellular oxidative stress has gained popularity worldwide. Aspalathus linearis (rooibos) is a popular herbal tea that contains a novel antioxidant, aspalathin. Literature has reported on the antidiabetic, anti-inflammatory and free radical scavenging effects of rooibos. However, its protective effect against DCM has not been established. Therefore, this study investigated whether chronic exposure to an aqueous extract of fermented rooibos (FRE) has an ex vivo cardioprotective effect on hearts obtained from streptozotocin (STZ) induced diabetic rats. Adult Wistar rats were injected with 40 mg/kg of STZ. Two weeks after STZ injection, cardiomyocytes were isolated and cultured. Cultured cardiomyocytes were treated with FRE (1 and 10 μg/ml), vitamin E (50 μg/ml), and n-acetyl cysteine (1 mM) for 6 h, before exposure to either hydrogen peroxide (H₂O₂) or an ischemic solution. Cardiomyocytes exposed to H₂O₂ or an ischemic solution showed a decrease in metabolic activity and glutathione content with a concomitant increase in apoptosis and intracellular reactive oxygen species. Pretreatment with FRE was able to combat these effects and the observed amelioration was better than the known antioxidant vitamin E. This study provides evidence that an aqueous extract of fermented rooibos protects cardiomyocytes, derived from diabetic rats, against experimentally induced oxidative stress and ischemia.     

Doxorubicin induced neuro- and cardiotoxicities in experimental rats: Protection against oxidative damage by Theobroma cacao Stem bark

80 rats, randomly selected, were divided into 3 treatment groups: pre-, co- and post-treatment; consisting of 6 sub-groups each (5 rats per sub-group): baseline, normal saline (2 mL), α-lipoic acid (20 mg/kg body weight), 200 mg/kg, 400 mg/kg or 800 mg/kg body weight Theobroma cacao stem bark aqueous extract (TCAE). All rats except for baseline group were intoxicated with 20 mg/kg body weight doxorubicin (DOX) intraperitoneally. The animals in pre- or post-treatment group received a single dose of DOX (20 mg/kg body weight) intraperitoneally 24 h before or after 7 days’ oral administration with TCAE respectively while those in co-treatment group were co-administered 2.86 mg/kg body weight of DOX with either normal saline, α- lipoic acid or TCAE orally for 7 days. Animals were sacrificed (pre- and post- treatment groups were sacrificed on the ninth day while the co-treatment group sacrificed on the 8th day). Brain and heart tissue samples were harvested for enzyme markers of toxicity, oxidative stress and histopathological examinations. DOX intoxication caused significant decrease in activities of LDH and ACP, and increase in γGT and ALP activities in brain tissues while causing a significant increase in LDH, ACP, γGT activities and decrease in ALP activity in the cardiac tissues. DOX intoxication caused a significant increase in concentrations of H₂O₂ generated, MDA and PC, XO, MPx and NOX activities with concomitant decrease in CAT, SOD, GPx and GST activities, and in concentrations of GSH, AsA and α-Toc in brain and cardiac tissues. Pre-, co- and post-treatment with TCAE at either 200 mg/kg, 400 mg/kg or 800 mg/kg body weight significantly reversed the oxidative damage to the organs induced by DOX-intoxication. The result affirmed that T. cacao stem bark aqueous extract protected against DOX induced oxidative damage in brain and cardiac tissues of experimental rats.     

Ameliorative effect of 20-OH ecdysone on streptozotocin induced oxidative stress and β-cell damage in experimental hyperglycemic rats

The present study was to evaluate the effects of 20-OH ecdysone on hyperglycemia mediated oxidative stress in streptozotocin induced diabetic rats. Diabetes was induced in experimental rats by single intraperitoneal injection of STZ (45 mg/kg b.w.) dissolved in 0.1 mol/L citrate buffer (pH 4.5). Diabetic rats exhibited increased blood glucose with significant decrease in plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and the levels of non-enzymic antioxidants vitamin C, vitamin E and reduced glutathione (GSH) were decreased while increases in the levels of LPO markers were observed in liver and kidney tissues of diabetic rats. Moreover, hepatic markers (aspartate aminotransferase and alanine aminotransferase) and renal markers (urea, creatinine) were significantly increased in diabetic rats as compared to control rats. Upon treatment with 20-OH ecdysone to diabetic rats showed significant ameliorative effects on all the biochemical parameters studied. Biochemical findings were supported by histological studies. These results indicated that 20-OH ecdysone exerts a protective action on pancreatic beta cell function and overcomes oxidative stress through its hypoglycemic potential. The effect produced by the 20-OH ecdysone on various parameters was comparable to that of glibenclamide – an antidiabetic drug.     

Modulation of PPAR-γ by telmisartan protects the heart against myocardial infarction in experimental diabetes

Telmisartan, an angiotensin II-receptor blocker (ARB), is a partial agonist of the peroxisome proliferator-activated receptor-gamma (PPAR-γ). We investigated whether telmisartan improved the pathophysiology of myocardial infarction in diabetes partially through the PPAR-γ pathway by assessing a variety of indices, e.g., hemodynamic, biochemical, histoarchitectural changes, and apoptosis. Diabetes was induced by a single dose of streptozotocin (70 mg/kg, IP). Diabetic rats received either telmisartan (10 mg/kg/day, orally), the PPAR-γ antagonist GW9662 (1 mg/kg/day, IP), or both for 14 days with concurrent administration of isoproterenol (85 mg/kg, SC) on days 13 and 14. Compared with diabetic controls, diabetic rats with myocardial infarction exhibited altered hemodynamic profiles and reduction in the activities of creatine kinase-MB isoenzyme, lactate dehydrogenase, superoxide dismutase, catalase, and glutathione level along with increased level of malondialdehyde in the heart. Further, diabetic animals with myocardial infarction exhibited increased myonecrosis, edema, and apoptotic cell death. Treatment with telmisartan significantly improved the redox status of the myocardium with subsequent cardiac functional recovery. However, significant effects were lowered in animals treated with telmisartan plus GW9662. Telmisartan markedly inhibited Bax expression, TUNEL-positive cells, myonecrosis, and edema. On the other hand, administration of telmisartan plus GW9662 did not elicit the same effects, nor did they increase Bcl-2 protein expression in isoproterenol-induced myocardially infarcted diabetic rats when administered concomitantly or individually. Moreover, down-regulated PPAR-γ expression in myocardially infarcted diabetic hearts was increased by telmisartan treatment. In addition to class effects of ARBs, telmisartan reduces oxidative stress and apoptosis and improves cardiac function via the PPAR-γ pathway.     

Effect of gold nanoparticles on glutathione and malondialdehyde levels in liver,lung and heart of rats

We studied the effect of gold nanoparticles (NPs) on oxidative stress markers including reduced glutathione (GSH) and malondialdehyde (MDA) in different organs of rats. Adult male Wistar-Kyoto rats were randomly divided into 3 groups of 5 animals each. One group served as control and received vehicle only. The remaining two groups were treated with 50 μl of 10 nm sized gold NPs, daily for 3 and 7 days, respectively. The rats were sacrificed 24 h after the last injection of NPs. Administration of gold NPs did not cause any significant change in GSH levels in liver, lung and heart on day 3 or day 7. There was no significant effect of gold NPs on MDA levels in lung and heart whereas significant increases in MDA levels were found in the liver of rats treated with gold nanoparticles on both 3 and 7 days post-dosing (ANOVA F = 7.113, P = 0.010). In conclusion, the findings of this preliminary study suggest that gold NPs of 10 nm diameter produce significant lipid peroxidation in rat liver however lungs and heart do not show any oxidative stress. Further studies are warranted to examine the effects of a broader dose range of gold NPs on the levels of free radical indices in different organs of rats.     

Cardioprotective effects of lipoic acid,quercetin and resveratrol on oxidative stress related to thyroid hormone alterations in long-term obesity

This study investigated possible mechanisms for cardioprotective effects of lipoic acid (LA), quercetin (Q) and resveratrol (R) on oxidative stress related to thyroid hormone alterations in long-term obesity. Female C57BL/6 mice were fed on high-fat diet (HFD), HFD + LA, HFD + R, HFD + Q and normal diet for 26 weeks. Body weight, blood pressure, thyroid hormones, oxidative stress markers, angiotensin converting enzyme (ACE), nitric oxide synthase (NOS) and ion pump activities were measured, and expression of cardiac genes was analyzed by real-time polymerase chain reaction. HFD induced marked increase (P < .05) in body weight, blood pressure and oxidative stress, while plasma triidothyronine levels reduced. ACE activity increased (P < .05) in HFD mice (0.69 ± 0.225 U/mg protein) compared with controls (0.28 ± 0.114 U/mg protein), HFD + LA (0.231 ± 0.02 U/mg protein) and HFD + Q (0.182 ± 0.096 U/mg protein) at 26 weeks. Moreover, Na⁺/K⁺-ATPase and Ca^2 +-ATPase activities increased in HFD mice whereas NOS reduced. A 1.5-fold increase in TRα1 and reduction in expression of the deiodinase iodothyronine DIO1, threonine protein kinase and NOS3 as well as up-regulation of AT1α, ACE, ATP1B1, GSK3β and Cja1 genes also occurred in HFD mice. Conversely, LA, Q and R inhibited weight gain; reduced TRα1 expression as well as increased DIO1; reduced ACE activity and AT1α, ATP1B1 and Cja1 gene expression as well as inhibited GSK3β; increased total antioxidant capacity, GSH and catalase activity; and reduced blood pressure. In conclusion, LA, resveratrol and quercetin supplementation reduces obesity thereby restoring plasma thyroid hormone levels and attenuating oxidative stress in the heart and thus may have therapeutic potential in heart diseases.     

Intramyocardial and intracoronary autologous bone marrow-derived mesenchymal stromal cell treatment in chronic severe dilated cardiomyopathy

Background aimsMesenchymal stromal cells (MSC) may improve cardiac function following myocardial infarction. MSC can differentiate into cardiomyocytes and endothelial cells while exerting additional paracrine effects. There is limited information regarding the efficacy of route for MSC treatment of severe dilated cardiomyopathy (DCM). The aim of this study was to demonstrate the clinical safety, feasibility and efficacy of direct intramyocardial and intracoronary administration of autologous bone marrow-derived MSC treatment for no-option patients with chronic severe refractory DCM.MethodsTen symptomatic patients with DCM and refractory cardiac function, despite maximum medical therapy, were selected. Five had ischemic DCM deemed unlikely to benefit from revascularization alone and underwent bypass operations with concurrent intramyocardial MSC injection (group A). Two patients had previous revascularization and three had non-ischemic DCM and received intracoronary MSC injection (group B).ResultsGroup A and B patients received 0.5–1.0 × 10⁶ and 2.0–3.0 × 10⁶ MSC/kg body weight, respectively. All patients remained alive at 1 year. There were significant improvements from baseline to 6 and 12 months in left ventricular ejection fraction and other left ventricular parameters. Scar reduction was noted in six patients by 12 months.ConclusionsAutologous bone marrow MSC treatment is safe and feasible for treating chronic severe refractory DCM effectively, via intracoronary or direct intramyocardial administration at prescribed doses.     

Differential regulation of extracellular matrix constituents in myocardial remodeling with and without heart failure following pressure overload

Patients with aortic stenosis develop various degrees of myocardial hypertrophy and heart failure (HF) despite comparable transvalvular gradients. An important element in the transition from compensated hypertrophy to HF is dilatation of the left ventricle (LV). The molecular pathology associated with LV dilatation and development of HF is not known. Thus, we examined potential differences in the regulation of myocardial extracellular matrix (ECM) constituents in mice with hypertrophy only (ABnonHF) and with HF (ABHF) as response to comparable pressure overload. The ascending aorta was banded, or left loose in sham-operated mice. Increased lung weight and left atrial diameter indicating pulmonary congestion were used to identify ABHF mice. Cardiac function and geometry were evaluated by echocardiography. Despite comparable pressure gradients and cardiac output, ABHF had reduced fractional shortening (23%), reduced systolic (28%) and diastolic (32%) tissue velocity and increased LV internal dimension in diastole (10%) and systole (17%) (LVIDd/s) compared to ABnonHF (p ≤ 0.05). Microarray analyses identified 120 differently regulated genes related to ECM in ABHF compared to ABnonHF (p ≤ 0.05). Interestingly, in ABHF, we found a 24% (p ≤ 0.05) reduction of the LV collagen VIII protein levels despite increased levels of LV total collagen by 23% (p ≤ 0.05). LV collagen VIII correlated negatively with LVIDd (R = 0.55, p = 0.03) and LVIDs (R = 0.72, p = 0.002). As this protein may function as a “sealant” binding collagen fibrils together, reduction of collagen VIII could potentially contribute to LV dilatation and development of HF.     

Beneficial effects of edaravone, a novel antioxidant, in rats with dilated cardiomyopathy

Edaravone, a novel antioxidant, acts by trapping hydroxyl radicals, quenching active oxygen and so on. Its cardioprotective activity against experimental autoimmune myocarditis (EAM) was reported. Nevertheless, it remains to be determined whether edaravone protects against cardiac remodelling in dilated cardiomyopathy (DCM). The present study was undertaken to assess whether edaravone attenuates myocardial fibrosis, and examine the effect of edaravone on cardiac function in rats with DCM after EAM. Rat model of EAM was prepared by injection with porcine cardiac myosin 28 days after immunization, we administered edaravone intraperitoneally at 3 and 10 mg/kg/day to rats for 28 days. The results were compared with vehicle-treated rats with DCM. Cardiac function, by haemodynamic and echocardiographic study and histopathology were performed. Left ventricular (LV) expression of NADPH oxidase subunits (p47(phox), p67(phox), gp91(phox) and Nox4), fibrosis markers (TGF-β(1) and OPN), endoplasmic reticulum (ER) stress markers (GRP78 and GADD 153) and apoptosis markers (cytochrome C and caspase-3) were measured by Western blotting. Edaravone-treated DCM rats showed better cardiac function compared with those of the vehicle-treated rats. In addition, LV expressions of NADPH oxidase subunits levels were significantly down-regulated in edaravone-treated rats. Furthermore, the number of collagen-III positive cells in the myocardium of edaravone-treated rats was lower compared with those of the vehicle-treated rats. Our results suggest that edaravone ameliorated the progression of DCM by modulating oxidative and ER stress-mediated myocardial apoptosis and fibrosis.     

Protective effect of Piper betle leaf extract against cadmium-induced oxidative stress and hepatic dysfunction in rats

The present study was undertaken to examine the attenuative effect of Piper betle leaf extract (PBE) against cadmium (Cd) induced oxidative hepatic dysfunction in the liver of rats. Pre-oral supplementation of PBE (200 mg/kg BW) treated rats showed the protective efficacy against Cd induced hepatic oxidative stress. Oral administration of Cd (5 mg/kg BW) for four weeks to rats significantly (P > 0.05) elevated the level of serum hepatic markers such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT), bilirubin (TBRNs), oxidative stress markers viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyls (PC) and conjugated dienes (CD) and significantly (P > 0.05) reduced the enzymatic antioxidants viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) and non-enzymatic antioxidants Viz., reduced glutathione (GSH), total sulfhydryls (TSH), vitamin C and vitamin E in the liver. Pre-oral supplementation of PBE (200 mg/kg BW) in Cd intoxicated rats, the altered biochemical indices and pathological changes were recovered significantly (P > 0.05) which showed ameliorative effect of PBE against Cd induced hepatic oxidative stress. From the above findings, we suggested that the pre-administration of P. betle leaf extract exhibited remarkable protective effects against cadmium-induced oxidative hepatic injury in rats.     

Telmisartan acts through the modulation of ACE-2/ANG 1-7/mas receptor in rats with dilated cardiomyopathy induced by experimental autoimmune myocarditis

AimRecent findings have suggested that a therapeutic approach to amplify or stimulate the angiotensin-converting enzyme-2 [ACE-2]-angiotensin 1–7 [ANG 1–7] mas axis could provide protection against the development of cardiovascular diseases. We investigated the cardioprotective effects of telmisartan in rats with dilated cardiomyopathy [DCM] after experimental autoimmune myocarditis [EAM].Main methodsDCM was elicited in Lewis rats by immunization with cardiac myosin, and twenty-eight days after immunization, the surviving Lewis rats were divided into two groups and treated with either telmisartan (10 mg/kg/day) or vehicle.Key findingsTelmisartan treatment effectively suppressed myocardial protein and mRNA expressions of inflammatory markers [CD68, iNOS, NF-kB, interleukin-1β, interferon-γ, monocyte chemotactic protein-1] in comparison to vehicle-treated rats. In contrast, myocardial protein levels of ACE-2 and ANG 1–7 mas receptor were upregulated in the telmisartan-treated group compared with vehicle-treated rats. Telmisartan treatment significantly reduced fibrosis and hypertrophy and their marker molecules [OPN, CTGF, TGF-β1 and collagens I and III and atrial natriuretic peptide and GATA-4, respectively] compared with those of vehicle-treated rats. In addition, telmisartan treatment significantly lowered the protein expressions of NADPH oxidase subunits p47phox, p67phox, and superoxide production when compared with vehicle-treated rats. Telmisartan treatment significantly decreased the expression levels of mitogen-activated protein kinase (MAPK) signaling molecules than with those of vehicle-treated rats. Also, telmisartan treatment significantly improved LV systolic and diastolic function.SignificanceThese results indicate that telmisartan treatment significantly improved LV function and ameliorated the progression of cardiac remodeling through the modulation of ACE-2/ANG 1–7/Mas receptor axis in rats with DCM after EAM.