N-Acetyl Cysteine, Selenium, and Ascorbic Acid Rescue Diabetic Cardiac Hypertrophy via Mitochondrial-Associated Redox Regulators.

Metabolic disorders often lead to cardiac complications. Metabolic deregulations during diabetic conditions are linked to mitochondrial dysfunctions, which are the key contributing factors in cardiac hypertrophy. However, the underlying mechanisms involved in diabetes-induced cardiac hypertrophy are poorly understood. In the current study, we initially established a diabetic rat model by alloxan-administration, which was validated by peripheral glucose measurement. Diabetic rats displayed myocardial stiffness and fibrosis, changes in heart weight/body weight, heart weight/tibia length ratios, and enhanced size of myocytes, which altogether demonstrated the establishment of diabetic cardiac hypertrophy (DCH). Furthermore, we examined the expression of genes associated with mitochondrial signaling impairment. Our data show that the expression of PGC-1α, cytochrome c, MFN-2, and Drp-1 was deregulated. Mitochondrial-signaling impairment was further validated by redox-system dysregulation, which showed a significant increase in ROS and thiobarbituric acid reactive substances, both in serum and heart tissue, whereas the superoxide dismutase, catalase, and glutathione levels were decreased. Additionally, the expression levels of pro-apoptotic gene PUMA and stress marker GATA-4 genes were elevated, whereas ARC, PPARα, and Bcl-2 expression levels were decreased in the heart tissues of diabetic rats. Importantly, these alloxan-induced impairments were rescued by N-acetyl cysteine, ascorbic acid, and selenium treatment. This was demonstrated by the amelioration of myocardial stiffness, fibrosis, mitochondrial gene expression, lipid profile, restoration of myocyte size, reduced oxidative stress, and the activation of enzymes associated with antioxidant activities. Altogether, these data indicate that the improvement of mitochondrial dysfunction by protective agents such as N-acetyl cysteine, selenium, and ascorbic acid could rescue diabetes-associated cardiac complications, including DCH.

Untargeted metabolomics and lipidomics uncovering the cardioprotective effects of Huanglian Jiedu Decoction on pathological cardiac hypertrophy and remodeling.

ETHNOPHARMACOLOGICAL RELEVANCE: As a classic herbal prescription, Huanglian Jiedu Decoction (HLJDD) exhibits positive effects against cardiac dysfunction. However, its cardioprotective effects and potential mechanism(s) of action still need to be systematically investigated. AIM OF THE STUDY: This study aimed to reveal the underlying therapeutic mechanism of HLJDD on transverse aortic constriction (TAC)-induced pathological cardiac hypertrophy and remodeling. MATERIALS AND METHODS: TAC-induced cardiac hypertrophy and remodeling mice model was established to evaluate the therapeutic effects of HLJDD. Serum untargeted metabolomics and lipidomic profiling were performed using ultra-performance liquid chromatography quadrupole-time-of-flight mass spectrometry coupled with multivariate statistical analyses. RESULTS: Oral administration of HLJDD (2.5 g/kg/day, 5.0 g/kg/day) significantly improved the heart morphology, enhanced the heart function, and alleviated the accumulation of fibrosis in the interstitial space and the infiltration of inflammatory cells in TAC-stimulated mice. Serum untargeted metabolomics analysis showed that significant alterations were observed in metabolic signatures between the TAC-model and sham group. Principal component analysis and orthogonal partial least-squares discriminant analysis screened 59 differential metabolic features and 13 metabolites were identified. The disturbed metabolic pathways in TAC group mainly related to lipid metabolism. Further serum lipidomic profiling showed that most lipids including cholesterol esters, ceramides, glycerides, fatty acids and phospholipids were decreased in TAC group and these alterations were reversed after HLJDD intervention. CONCLUSION: HLJDD alleviates TAC-induced pathological cardiac hypertrophy and remodeling, and its potential therapeutic mechanism involves the regulation of lipid metabolism.

Supplemental 25-hydroxycholecalciferol Alleviates Inflammation and Cardiac Fibrosis in Hens.

Broiler breeder hens with efficient feed conversion rate under restricted feed intake (R-hens) or allowed unlimited access to feed (Ad-hens) progressed with cardiac functional failure and suffered early sudden death. A supplement of 69 µg 25-hydroxycholecalciferol (25-OH-D3)/kg feed improved heart health and rescued livability in both R- and Ad-hens throughout laying stage (26-60 wks). Improvements occurred through cardiac hypertrophic remodeling, reduced arrhythmias, and pathological cues. Here, we further demonstrated consistently decreased circulating and cardiac IL-6 and IL-1ß levels in conjunction with reduced cardiac chemoattraction and leukocyte infiltration by 25-OH-D3 in Ad-hens and in R-hens at later time points (35 and 47 wks) (p < 0.05). Supplemental 25-OH-D3 also ameliorated cardiac fibrosis, endoplasmic reticulum (ER) stress, and autophagy, mostly in Ad-hens, as both collagen content and expression of COL3A1, as well as CCAAT box binding enhancer homologous protein (CHOP) and activating transcription factor 6 (ATF6), were consistently decreased, and suppression of microtubule-associated protein 1 light Chain 3 beta (LC3B) and Sequestosome 1 (SQSTM1) was rescued at 35 and 47 wks (p < 0.05). Vitamin D receptor-NF-κB signaling was shown to mediate these beneficial effects. The present results demonstrate that ER stress and autophagic processes along the sequence from inflammation to fibrotic changes contribute to pathological cardiac remodeling and functional compromise by Ad-feed intake. 25-OH-D3 is an effective anti-inflammatory and anti-fibrotic supplement to ameliorate cardiac pathogenesis in broiler breeder hens.

Allylmethylsulfide, a Sulfur Compound Derived from Garlic, Attenuates Isoproterenol-Induced Cardiac Hypertrophy in Rats.

Allylmethylsulfide (AMS) is a novel sulfur metabolite found in the garlic-fed serum of humans and animals. In the present study, we have observed that AMS is safe on chronic administration and has a potential antihypertrophic effect. Chronic administration of AMS for 30 days did not cause any significant differences in the body weight, electrocardiogram, food intake, serum biochemical parameters, and histopathology of vital organs. Single-dose pharmacokinetics of AMS suggests that AMS is rapidly metabolized into Allylmethylsulfoxide (AMSO) and Allylmethylsulfone (AMSO2). To evaluate the efficacy of AMS, cardiac hypertrophy was induced by subcutaneous implantation of ALZET® osmotic minipump containing isoproterenol (~5 mg/kg/day), cotreated with AMS (25 and 50 mg/kg/day) and enalapril (10 mg/kg/day) for 2 weeks. AMS and enalapril significantly reduced cardiac hypertrophy as studied by the heart weight to body weight ratio and mRNA expression of fetal genes (ANP and ß-MHC). We have observed that TBARS, a parameter of lipid peroxidation, was reduced and the antioxidant enzymes (glutathione, catalase, and superoxide dismutase) were improved in the AMS and enalapril-cotreated hypertrophic hearts. The extracellular matrix (ECM) components such as matrix metalloproteinases (MMP2 and MMP9) were significantly upregulated in the diseased hearts; however, with the AMS and enalapril, it was preserved. Similarly, caspases 3, 7, and 9 were upregulated in hypertrophic hearts, and with the AMS and enalapril treatment, they were reduced. Further to corroborate this finding with in vitro data, we have checked the nuclear expression of caspase 3/7 in the H9c2 cells treated with isoproterenol and observed that AMS cotreatment reduced it significantly. Histopathological investigation of myocardium suggests AMS and enalapril treatment reduced fibrosis in hypertrophied hearts. Based on our experimental results, we conclude that AMS, an active metabolite of garlic, could reduce isoproterenol-induced cardiac hypertrophy by reducing oxidative stress, apoptosis, and stabilizing ECM components.

Application of Zebrafish Model in the Suppression of Drug-Induced Cardiac Hypertrophy by Traditional Indian Medicine Yogendra Ras.

Zebrafish is an elegant vertebrate employed to model the pathological etiologies of human maladies such as cardiac diseases. Persistent physiological stresses can induce abnormalities in heart functions such as cardiac hypertrophy (CH), which can lead to morbidity and mortality. In the present study, using zebrafish as a study model, efficacy of the traditional Indian Ayurveda medicine "Yogendra Ras" (YDR) was validated in ameliorating drug-induced cardiac hypertrophy. YDR was prepared using traditionally described methods and composed of nano- and micron-sized metal particles. Elemental composition analysis of YDR showed the presence of mainly Au, Sn, and Hg. Cardiac hypertrophy was induced in the zebrafish following a pretreatment with erythromycin (ERY), and the onset and reconciliation of disease by YDR were determined using a treadmill electrocardiogram, heart anatomy analysis, C-reactive protein release, and platelet aggregation time-analysis. YDR treatment of CH-induced zebrafish showed comparable results with the Standard-of-care drug, verapamil, tested in parallel. Under in-vitro conditions, treatment of isoproterenol (ISP)-stimulated murine cardiomyocytes (H9C2) with YDR resulted in the suppression of drug-stimulated biomarkers of oxidative stress: COX-2, NOX-2, NOX-4, ANF, troponin-I, -T, and cardiolipin. Taken together, zebrafish showed a strong disposition as a model for studying the efficacy of Ayurvedic medicines towards drug-induced cardiopathies. YDR provided strong evidence for its capability in modulating drug-induced CH through the restoration of redox homeostasis and exhibited potential as a viable complementary therapy.

Pathological hypertrophy and cardiac dysfunction are linked to aberrant endogenous unsaturated fatty acid metabolism.

Pathological cardiac hypertrophy leads to derangements in lipid metabolism that may contribute to the development of cardiac dysfunction. Since previous studies, using high saturated fat diets, have yielded inconclusive results, we investigated whether provision of a high-unsaturated fatty acid (HUFA) diet was sufficient to restore impaired lipid metabolism and normalize diastolic dysfunction in the pathologically hypertrophied heart. Male, Wistar rats were subjected to supra-valvar aortic stenosis (SVAS) or sham surgery. After 6 weeks, diastolic dysfunction and pathological hypertrophy was confirmed and both sham and SVAS rats were treated with either normolipidic or HUFA diet. At 18 weeks post-surgery, the HUFA diet failed to normalize decreased E/A ratios or attenuate measures of cardiac hypertrophy in SVAS animals. Enzymatic activity assays and gene expression analysis showed that both normolipidic and HUFA-fed hypertrophied hearts had similar increases in glycolytic enzyme activity and down-regulation of fatty acid oxidation genes. Mass spectrometry analysis revealed depletion of unsaturated fatty acids, primarily linoleate and oleate, within the endogenous lipid pools of normolipidic SVAS hearts. The HUFA diet did not restore linoleate or oleate in the cardiac lipid pools, but did maintain body weight and adipose mass in SVAS animals. Overall, these results suggest that, in addition to decreased fatty acid oxidation, aberrant unsaturated fatty acid metabolism may be a maladaptive signature of the pathologically hypertrophied heart. The HUFA diet is insufficient to reverse metabolic remodeling, diastolic dysfunction, or pathologically hypertrophy, possibly do to preferentially partitioning of unsaturated fatty acids to adipose tissue.

Delonix regia Leaf Extract (DRLE): A Potential Therapeutic Agent for Cardioprotection.

Delonix regia (Boj. Ex. Hook) is a flowering plant in the pea family found in tropical areas and its leaves are used informally to treat diseases in folk medicine. However, the cardioprotective effects in this plant are still unclear. In this study, we found that the Delonix regia leaf extract (DRLE) (400 mg/kg/d) can reduce the mortality rate in an isoproterenol (ISO)-induced heart injury and hypertrophy mouse model. Decreased serum levels of creatine phosphokinase, LDH, GOT, TNF-alpha and increased nitric oxide levels were found in DRLE-treated ISO-injured mice. In the in vitro study, the porcine coronary artery exhibited vasodilation effect induced by DRLE in a dose-dependent manner. In the DRLE toxic test, overdose of DRLE showed the high safety in normal mice and may have the ability to remove the metabolic wastes in blood. In conclusion, we demonstrated for the first time that DRLE has the cardioprotective effects by activating the vasodilation through NO pathway and preventing the myocyte injury via inhibition of TNF-alpha pathway. We suggest that DRLE may act as a promising novel herbal medicine for cardioprotection.

Choline Diet and Its Gut Microbe-Derived Metabolite, Trimethylamine N-Oxide, Exacerbate Pressure Overload-Induced Heart Failure.

BACKGROUND: Trimethylamine N-oxide (TMAO), a gut microbe-dependent metabolite of dietary choline and other trimethylamine-containing nutrients, is both elevated in the circulation of patients having heart failure and heralds worse overall prognosis. In animal studies, dietary choline or TMAO significantly accelerates atherosclerotic lesion development in ApoE-deficient mice, and reduction in TMAO levels inhibits atherosclerosis development in the low-density lipoprotein receptor knockout mouse. METHODS AND RESULTS: C57BL6/J mice were fed either a control diet, a diet containing choline (1.2%) or a diet containing TMAO (0.12%) starting 3 weeks before surgical transverse aortic constriction. Mice were studied for 12 weeks after transverse aortic constriction. Cardiac function and left ventricular structure were monitored at 3-week intervals using echocardiography. Twelve weeks post transverse aortic constriction, myocardial tissues were collected to evaluate cardiac and vascular fibrosis, and blood samples were evaluated for cardiac brain natriuretic peptide, choline, and TMAO levels. Pulmonary edema, cardiac enlargement, and left ventricular ejection fraction were significantly (P<0.05, each) worse in mice fed either TMAO- or choline-supplemented diets when compared with the control diet. In addition, myocardial fibrosis was also significantly greater (P<0.01, each) in the TMAO and choline groups relative to controls. CONCLUSIONS: Heart failure severity is significantly enhanced in mice fed diets supplemented with either choline or the gut microbe-dependent metabolite TMAO. The present results suggest that additional studies are warranted examining whether gut microbiota and the dietary choline → TMAO pathway contribute to increased heart failure susceptibility.

Cissampelos pareira Linn. ameliorates thyroxin-induced cardiac hypertrophy in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cissampelos pareira extract has been traditionally used in ayruveda as cardiotonic, diuretics and in heart complains but its pharmacological evaluation in thyroxin-induced cardiac hypertrophy has not yet been explored. AIM OF THE STUDY: The aim of this study was to assess the cardioprotective effect of C. pareira root extract in experimentally induced hyperthyroidism in rats. MATERIALS AND METHODS: Male Wistar rats were treated with (i) thyroxin (0.1 mg/kg/day, i.p.) for 30 days, (ii) C. pareira extract (200 mg/kg/day, p.o.) alone for 60 days, (iii) C. pareira extract (100 and 200 mg/kg/day, p.o., respectively) for 30 days then with thyroxin for another 30 days, (iv) thyroxin for 30 days then C. pareira extract (100 and 200 mg/kg/day, p.o., respectively) for another 30 days. At the end of experiment, serum calcineurin, nitric oxide, lactate dehydrogenase, and thiobarbituric acid reactive substance as well as serum and/or myocardial antioxidant enzymes activity were estimated. RESULTS: Hyperthyroid induced cardiotoxicity was characterized by a significant (P<0.001) increase in heart weight/body weight ratio, serum calcineurin, nitric oxide, lactate dehydrogenase and thiobarbituric acid reactive substance levels as well as a significant decrease in serum reduced glutathione, myocardial glutathione peroxidase, glutathione reductase and glutathione-S-transferase levels, which were significantly (P<0.05 and P<0.01) reverted by C. pareira extract treatment. Reversal of histological changes on treatment with C. pareira extract was also supported the biochemical parameters. These results were quite comparable with amlodipine, the standard drug taken in this study. CONCLUSIONS: Treatment with C. pareira extract ameliorates thyroxin-induced oxidative stress and cardiac hypertrophy, probably through amelioration of calcineurin activity and augmentation of antioxidant enzyme activities.

Improved intervention of atherosclerosis and cardiac hypertrophy through biodegradable polymer-encapsulated delivery of glycosphingolipid inhibitor.

D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), a glycosphingolipid synthesis inhibitor, holds promise for the treatment of atherosclerosis and cardiac hypertrophy but rapid in vivo clearance has severely hindered translation to the clinic. To overcome this impediment, we used a materials-based delivery strategy wherein D-PDMP was encapsulated within a biodegradable polymer composed of poly ethylene glycol (PEG) and sebacic acid (SA). PEG-SA was formulated into nanoparticles that were doped with (125)I-labeled PEG to allow in vivo bio-distribution and release kinetics of D-PDMP to be determined by using γ-scintigraphy and subsequently, by mass spectrometry. Polymer-encapsulation increased the residence time of D-PDMP in the body of a treated mouse from less than one hour to at least four hours (and up to 48 h or longer). This substantially increased in vivo longevity provided by polymer encapsulation resulted in an order of magnitude gain in efficacy for interfering with atherosclerosis and cardiac hypertrophy in apoE-/- mice fed a high fat and high cholesterol (HFHC) diet. These results establish that D-PDMP encapsulated in a biodegradable polymer provides a superior mode of delivery compared to unconjugated D-PDMP by way of increased gastrointestinal absorption and increased residence time thus providing this otherwise rapidly cleared compound with therapeutic relevance in interfering with atherosclerosis, cardiac hypertrophy, and probably other diseases associated with the deleterious effects of abnormally high glycosphingolipid biosynthesis or deficient catabolism.

Effect of Cissampelos pareira root extract on isoproterenol-induced cardiac dysfunction.

The aim of this study was to assess the cardioprotective effect of Cissampelos pareira root extract on isoproterenol-induced cardiac dysfunction in rats. Male albino Wistar rats were randomly divided into eight groups and received either normal saline (0.5 ml/kg, intraperitoneally), isoproterenol (5 mg/kg, intraperitoneally), C. pareira (100 and 200 mg/kg, by gavage, respectively) alone, amlodipine (9 mg/kg, by gavage) alone, C. pareira (100 and 200 mg/kg, respectively) + isoproterenol and amlodipine (9 mg/kg) + isoproterenol, once a day for 30 days, respectively. Isoproterenol-induced cardiac dysfunction was characterized by a significant (P < 0.001) increase in the heart weigh/body weight ratio, serum calcineurin, nitric oxide, lactate dehydrogenase, and thiobarbituric acid reactive substance levels, as well as a significant decrease in serum-reduced glutathione, cardiac glutathione peroxidase, glutathione reductase, and glutathione-S-transferase levels, which were significantly (P < 0.05 and P < 0.01) improved by C. pareira treatment. No significant alteration was observed in the group treated with C. pareira alone compared with the control. C. pareira treatment also restored histopathological changes observed in isoproterenol-induced rats. Amlodipine is used as standard drug in this study. Thus, these results suggest that the attenuation of isoproterenol-induced cardiac dysfunction by treatment with ethanolic root extract of C. pareira may be due to amelioration of calcineurin activity and free radical formation, and by augmentation of antioxidant enzymes activities.

Cardiac lipoprotein lipase activity in the hypertrophied heart may be regulated by fatty acid flux.

Cardiac hypertrophy is characterised by an imbalance between lipid uptake and fatty acid ß-oxidation leading to an accumulation of lipids, particularly triacylglycerol (TAG). It is unclear whether uptake mechanisms such as lipoprotein lipase (LPL) can be attenuated to diminish this uptake. Rats were cold acclimated to induce cardiac hypertrophy and increase cardiac LPL. Lipid uptake and metabolism were altered by feeding a 'Western-style' high fat diet (WSD) or feeding oxfenicine (2g/L) in the drinking water. Diastolic stiffness (increased volume change/unit pressure change) was induced in hypertrophied hearts for rats fed WSD (P<0.05) or WSD+oxfenicine (P<0.01), although absolute performance of cardiac muscle, estimated from stress-strain calculations was unchanged. Cold acclimation increased cardiac endothelial LPL (P<0.05) but this was diminished following oxfenicine. Following WSD LPL was further decreased below WSD-fed control hearts (P<0.05) with no further decrease by oxfenicine supplementation. A negative correlation was noted between plasma TAG and endothelial LPL (correlation coefficient=-0.654; P<0.001) but not cardiac TAG concentration. Transcript levels of angiopoietin-like protein-4 (ANGPTL4) were increased 6-fold by WSD (P<0.05) and increased 15-fold following WSD+oxfenicine (P<0.001). For CA-hearts fed WSD or WSD+oxfenicine ANGPTL4 mRNA levels were preserved at chow-fed levels. VLDLR protein levels were increased 10-fold (P<0.01) by CA. ANGPTL4 protein levels were increased 2-fold (P<0.05) by WSD, but restored following oxfenicine. For CA-hearts WSD increased ANGPTL4 protein levels 3-fold (P<0.01) with WSD+oxfenicine increasing ANGPTL4 protein 4-fold (P<0.01). These data suggest that endothelial LPL levels in the heart are altered to maintain FA flux and may exploit ANGPTL4.

Adverse effects of hyperphosphatemia on myocardial hypertrophy, renal function, and bone in rats with renal failure.

BACKGROUND: Hyperphosphatemia and disturbances in calcium or parathyroid hormone (PTH) metabolism contribute to the high incidence of cardiovascular disease and renal osteodystrophy in chronic renal failure (CRF). We evaluated the effect of hyperphosphatemia on the cardiovascular system, on renal function, and on bone in experimental uremia. METHODS: Wistar rats were submitted to parathyroidectomy (PTx) and 5/6 nephrectomy (Nx) with minipump implantation, delivering 1-34 rat PTH (physiologic rate), or were sham-operated and received vehicle. Only phosphorus content (low-phosphorus (LP) 0.2%; high-phosphorus (HP) 1.2%) differentiated diets. We divided the groups as follows: PTx +Nx +LP; sham + LP; PTx + Nx + HP; and sham + HP. Tail-cuff pressure and weight were measured weekly. After 2 months, biochemical, arterial, and myocardial histology and bone histomorphometry were analyzed. RESULTS: Heart weight normalized to body weight (heart weight/100 g body weight) was higher in PTx + Nx + HP rats (PTx + Nx + HP = 0.36 +/- 0.01 vs. sham + HP = 0.29 +/- 0.01, PTx + Nx + LP = 0.32 +/- 0.01, sham + LP = 0.28 +/- 0.01) (P < 0.05). Serum creatinine levels were higher in PTx + Nx + HP rats than in PTx + Nx + LP rats (1.09 +/- 0.13 vs. 0.59 +/- 0.03 mg/dL) (P < 0.05). Levels of PTH did not differ significantly between the groups. Myocardial and arterial histology detected no vascular calcification or fibrosis. Bone histomorphometry revealed an association, unrelated to uremia, between HP diets and decreased trabecular connectivity. CONCLUSION: Myocardial hypertrophy, impaired renal function, and adverse effects on bone remodeling were associated with hyperphosphatemia and were not corrected by PTH replacement. Although no vascular calcification was observed in this model, we cannot rule out an adverse effect of hyperphosphatemia on the vascular bed. Our finding underscores the importance of phosphorus control in reducing morbidity and mortality in CRF patients.

Increased blood kynurenine level as a factor inhibiting the therapeutic effect of antihypertensive agents in combined long-term treatment of essential hypertension.

Results of a three-year antihypertensive combined treatment of 24 male patients with essential hypertension aged 35-55 years are presented. In all patients the blood serum kynurenine level after tryptophan load was determined before treatment and after the 1st, 2nd and 3rd years of therapy. It was found that in a part of patients the long-term administration of antihypertensive drugs led to an increased accumulation of kynurenine as a manifestation of pyridoxal-5-phosphate deficiency. The development and preservation of an increased blood kynurenine level interferes with the positive effects of antihypertensive therapy as regards both blood pressure and left ventricular myocardial mass reduction.