Beneficial role of aminoguanidine on acute cardiomyopathy related to doxorubicin-treatment

Angiotensin II type 2 receptor agonist treatment of doxorubicin induced heart failure

Doxorubicin (DOX) is an anthracycline derivative used for treatment of malignancies; however, its clinical use is limited by its cardiotoxicity. We investigated the effects of angiotensin II type 2 receptor agonist compound 21 (C21) on DOX induced heart failure in rat heart. We compared C21 with losartan (LOS), an AT 1 receptor antagonist used for treating heart failure. We allocated 40 rats into five groups of eight: saline treated control group, DOX group administered a single 20 mg/kg dose of DOX, DOX + C21 group administered 0.3 mg/kg C21 for 21 days following the 20 mg/kg dose of DOX, DOX + losartan (LOS) group administered a 21 day regimen of 20 mg/kg LOS following the single dose of DOX, and a DOX + LOS + C21 group administered 0.3 mg/kg C21 and 20 mg/kg LOS for 21 days following the single dose of DOX. We assessed histopathology and conducted echocardiograpic and hemodynamic measurements. Left ventricular ejection fraction (EF) was reduced only in the DOX treated group. C21, LOS and C21 + LOS therapy prevented decreased EF due to DOX. Less histopathology was observed in the DOX + LOS + C21 group than for the other treatment groups. Application of C21 decreased DOX induced cardiac injury similar to LOS. Combined use of C21 and LOS was most beneficial for DOX induced heart failure.

Platycodon grandiflorum Protects Against Anthracycline-Induced Cardiotoxicity in Early Breast Cancer Patients

Background: Anthracycline-based chemotherapy is an effective treatment used for early-stage breast cancer patients. However, anthracycline use is limited due to its cardiotoxic effects. Recent studies have shown that Platycodon grandiflorum (PG) protects the heart from anthracycline-induced cardiotoxicity. However, no randomized, placebo-controlled clinical trial has been performed to investigate the clinical use of PG to prevent anthracycline-induced cardiotoxicity. This study aimed to evaluate the cardioprotective effects and safety of PG in early breast cancer patients receiving anthracycline-based chemotherapy. Methods: A total of 125 early breast cancer patients receiving anthracycline-based chemotherapy were enrolled and randomized into a PG group or placebo group in a 1:1 ratio. Results: Only 2 (3.1%) participants in the placebo group and 1 (1.6%) participant in the PG group experienced NYHA (New York Heart Association) class III or IV heart failure. There were no significant differences observed between the 2 groups. However, compared with the placebo group, patients in the PG group showed a lower incidence of subclinical heart failure (21.9% vs 8.2%, respectively, P = .033), as well as lower cardiac troponin T levels (48.4% vs 31.1%, respectively, P = .002). Importantly, there were no differences observed in the antitumor effects of anthracycline between the 2 groups (disease-free survival: hazards ratio = 1.09, 95% confidence interval = 0.45-2.62, P = .84; overall survival: hazards ratio = 1.46, 95% confidence interval = 0.33-6.43, P = .62). Conclusion: PG prevents anthracycline-induced acute and chronic cardiac injury in early-stage breast cancer patients without compromising the antitumor effects of chemotherapy.

In Vivo and In Vitro Protective Effects of Rosmarinic Acid against Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX) is an anticancer medicine that may trigger cardiomyopathy. Rosmarinic acid (RA) has shown antioxidant, anti-inflammatory, and anticancer effects. This investigation assessed the cardioprotective effect of RA on DOX-induced-toxicity in both in vivo and in vitro experiments. Male rats were randomized on 7 groups: (1) control, (2) DOX (2 mg/kg, per 48 h, 12d, i.p), (3) RA (40 mg/kg, 12d, i.p.), (4-6) RA (10, 20, 40 mg/kg, 16d, i.p.)+ DOX, (7) Vitamin E (200 mg/kg, per 48 h, 16d, i.p.) + DOX and then indices of cardiac function were estimated. Also, DOX and rosmarinic acid effects were examined on MCF7 cells (breast cancer cells line) to clarify that both cardiotoxicity and anticancer effects were analyzed. DOX increased heart to body weight ratio, RRI, QA, STI, QRS duration and voltage, attenuated HR, blood pressure, Max dP/dt, Min dP/dt, LVDP, enhanced MDA, declined GSH amount, and caused fibrosis and necrosis in cardiac tissue. Administration of RA ameliorated the toxic effects of DOX. In vitro studies showed that RA did not affect the cytotoxic effect of DOX. RA as an antioxidant, anti-inflammatory, and cardioprotective compound could be a promising compound to help minimize DOX-induced cardiotoxicity.

Aminoguanidine reduces diabetes-associated cardiac fibrosis

Aminoguanidine (AG) inhibits advanced glycation end products (AGEs) and advanced oxidation protein products (AOPP) accumulated as a result of excessive oxidative stress in diabetes. However, the molecular mechanism by which AG reduces AGE-associated damage in diabetes is not well understood. Thus, we investigated whether AG supplementation mitigates oxidative-associated cardiac fibrosis in rats with type 2 diabetes mellitus (T2DM). Forty-five male Wistar rats were divided into three groups: Control, T2DM and T2DM+AG. Rats were fed with a high-fat, high-carbohydrate diet (HFCD) for 2 weeks and rendered diabetic using low-dose streptozotocin (STZ) (20 mg/kg), and one group was treated with AG (20 mg/kg) up to 25 weeks. In vitro experiments were performed in primary rat myofibroblasts to confirm the antioxidant and antifibrotic effects of AG and to determine if blocking the receptor for AGEs (RAGE) prevents the fibrogenic response in myofibroblasts. Diabetic rats exhibited an increase in cardiac fibrosis resulting from HFCD and STZ injections. By contrast, AG treatment significantly reduced cardiac fibrosis, α-smooth muscle actin (αSMA) and oxidative-associated Nox4 and Nos2 mRNA expression. In vitro challenge of myofibroblasts with AG under T2DM conditions reduced intra- and extracellular collagen type I expression and Pdgfb, Tgfβ1 and Col1a1 mRNAs, albeit with similar expression of Tnfα and Il6 mRNAs. This was accompanied by reduced phosphorylation of ERK1/2 and SMAD2/3 but not of AKT1/2/3 and STAT pathways. RAGE blockade further attenuated collagen type I expression in AG-treated myofibroblasts. Thus, AG reduces oxidative stress-associated cardiac fibrosis by reducing pERK1/2, pSMAD2/3 and collagen type I expression via AGE/RAGE signaling in T2DM.

Korean Red Ginseng enhances cardiac hemodynamics on doxorubicin-induced toxicity in rats

Background

Korean Red Ginseng (KRG) has been known to possess many ginsenosides. These ginsenosides are used for curing cardiovascular problems. The present study show the protective potential of KRG against doxorubicin (DOX)–induced myocardial dysfunction, by assessing electrocardiographic, hemodynamic, and biochemical parameters and histopathological findings.

Methods

Animals were fed a standard chow and adjusted to their environment for 3 days before the experiments. Next, the rats were equally divided into five groups (n = 9, each group). The animals were administered with KRG (250 and 500 mg/kg) for 10 days and injected with DOX (20 mg/kg, subcutaneously, twice at a 24-h interval) on the 8th and 9th day. Electrocardiography and echocardiography were performed to study hemodynamics. Plasma levels of superoxide dismutase, catalase, glutathione peroxidase, and malondialdehyde were measured. In addition, the dose of troponin I and activity of myeloperoxidase in serum and cardiac tissue were analyzed, and the histopathological findings were evaluated using light microscopy.

Results

Administration of KRG at a dose of 250 and 500 mg/kg recovered electrocardiographic changes, ejection fraction, fractional shortening, left ventricular systolic pressure, the maximal rate of change in left ventricle contraction (+dP/dt_max), and left ventricle relaxation (-dP/dt_max). In addition, KRG treatment significantly normalized the oxidative stress markers in plasma, dose dependently. In addition, the values of troponin I and myeloperoxidase were ameliorated by KRG treatment, dose dependently. And, KRG treatment showed better histopathological findings when compared with the DOX control group.

Conclusion

These mean that KRG mitigates myocardial damage by modulating the hemodynamics, histopathological abnormality, and oxidative stress related to DOX-induced cardiomyopathy in rats. The results of the present study show protective effects of KRG on cardiac toxicity.

Protective and therapeutic effects of dexpanthenol on isoproterenol-induced cardiac damage in rats

The purpose of the study was to explore the protective and therapeutic effects of dexpanthenol (DEX) on isoproterenol (ISO)-induced cardiac damage. Forty rats were distributed into four groups: group I (Control); group II (ISO); ISO (150 mg/kg/day) was given to rats once a day for 2 consecutive days with an interval of 24 h; group III (DEX+ISO): DEX (250 mg/kg) was applied 30 min before the first ISO administration and continued in the next two days after second ISO administration; group IV (ISO+DEX): After the ISO treatment at 1st and 2nd days, DEX was given at 3rd and 4th days. Rats were monitored for mean arterial blood pressure (BP), heart rate, oxygen saturation (%SO₂ ), and electrocardiography (ECG). Heart tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), reduced glutathione (GSH), total oxidant status (TOS); total antioxidant capacity (TAC), oxidative stress index (OSI), and caspase-3 were determined. BP and SO₂ values indicated a significant decrease in the ISO group. Also, T wave negativity was observed in 6 of 10 rats, SOD, CAT, and GPX levels were significantly lower in ISO group than control group. ISO administration increased TOS and OSI levels, whereas DEX treatment significantly reduced these parameters. Also, ISO-induced morphological alterations such as disorganization of cardiomyocytes, loss of myofibrils and cytoplasmic vacuolization whereas these histological damages were significantly decreased in ISO+DEX and DEX+ISO groups when compared to the ISO group. This study implies the cardioprotective effects of DEX on ISO-induced cardiotoxicity.

Cardioprotective effect of Platycodon grandiflorum in patients with early breast cancer receiving anthracycline-based chemotherapy: study protocol for a randomized controlled trial

Background

Anthracyclines, alone or in combination with other drugs, are among the most effective chemotherapeutic agents to treat breast cancer both in the adjuvant and neoadjuvant setting. Unfortunately, anthracycline-associated dose-dependent cardiotoxicity is a limiting factor in clinical use. Extensive efforts have been devoted to identifying strategies to prevent anthracycline-induced cardiotoxicity. However, most cardioprotective agents have shown little effect in clinical trials. Herbal medicines are pure, natural substances that have been used for centuries in many countries, including China. This trial aims to evaluate the cardioprotective effects and safety of Platycodon grandiflorum granules compared to placebo granules in patients with early breast cancer receiving anthracycline-based chemotherapy.

Method/design

This study is a single-center, double-blinded, randomized, placebo-controlled, parallel-group trial. A total of 120 patients will be randomly allocated in a 1:1 ratio to receive either P. grandiflorum granules or placebo granules twice daily for 12 weeks. The primary outcome is heart failure (either clinical or subclinical). The secondary outcomes include all-cause mortality, cardiac death, electrocardiogram (ECG) findings, left ventricular diastolic function, longitudinal systolic strain and velocities measured by tissue Doppler imaging, cardiac biomarkers, such as troponin I (TnI), brain natriuretic peptide (BNP), and creatine kinase isoenzymes (CK-MB). Assessments will be performed at baseline (before randomization) and 3, 6, 9, 12, 16, and 20 weeks after randomization.

Discussion

This will be the first clinical trial to evaluate the cardioprotective effects and safety of P. grandiflorum in patients with early breast cancer receiving anthracycline-based chemotherapy. We are also performing this trial to assess the feasibility of a larger-scale clinical trial in the future.

Trail registration

Chinese Clinical Trial Registry, ChiCTR-IPR-16009256. Registered on 23 September 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2140-z) contains supplementary material, which is available to authorized users.

Imaging of early modification in cardiomyopathy: the doxorubicin-induced model

Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.

N-Acetylcysteine prevents doxorubucine-induced cardiotoxicity in rats

This study is designed to observe the effects of N-acetylcysteine (NAC) on doxorubucine-induced cardiac toxicity in rats both histologically and biochemically. Totally 32 rats divided equally into four groups were studied. The first group received only 200 mg/kg NAC intraperitoneal (i.p.) once every 24 h for 5 days (group 1); the second group received 20 mg/kg doxorubucine (DOX) i.p. single dose plus NAC 200 mg/kg i.p. once every 24 h for 5 days (group 2); the third group received DOX 20 mg/kg DOX i.p. single dose (group 3) and the fourth group, which is also the control group, received saline (group 4). Following 24 h of the final dose, blood samples were drawn from a portal vein and heart tissue were obtained. Tissue thiobarbituric acid reactive substance (TBARS) and nitric oxide (NO) levels were highest in the DOX group. In the DOX-treated rats, serum TBARS, NO, aspartate transaminase, lactate dehydrogenase and creatine kinase levels were highest when compared with other groups. Except for serum superoxide dismutase levels, all other parameters differed significantly between the DOX plus NAC group and the DOX group. In the DOX plus NAC group, general architecture was preserved better than the DOX group and myofibril loss was minimal compared with the DOX group. NAC demonstrated, both biochemically and histologically, to be effective in the prevention of DOX-induced cardiotoxicity in rat models. Evaluation of NAC’s effect on DOX toxicity warrants further clinical trials on cancer patients.

Therapeutic effects of ivabradine on hemodynamic parameters and cardiotoxicity induced by doxorubicin treatment in rat

The aim of this study was to investigate the possible effects of ivabradine against doxorubicin (DOX)-induced cardiotoxicity in rats using hemodynamic parameters (electrocardiogram, heart rate (HR), and blood pressure), biochemical markers of oxidative stress, lactate dehydrogenase, aspartate transaminase, creatine kinase-MB, and histopathological analyses both in serum and tissue specimens. A total of 28 female rats were randomly assigned to 4 groups: (a) control ( n = 6 rats), (b) DOX group ( n = 7 rats), (c) DOX + ivabradine–treated group ( n = 8 rats), and (d) ivabradine group ( n = 7 rats). When the means of the four groups were compared, there was only a significant difference in the level of HR ( p < 0.05). DOX treatment caused more HR elevation when compared to the control group, whereas ivabradine application after DOX treatment significantly reduced HR levels. Cardiomyocytes were revealed as normal histology in the light of both hematoxylin and eosin staining and immunostaining methods (caspase-3 and bcl-2) in all groups. The present study reported the therapeutic effects of ivabradine against DOX-induced cardiotoxicity accompanied by the hemodynamic and biochemical parameters.

Early toxicology signal generation in the mouse

The rat has been the preferred rodent toxicology species since before regulatory requirements have been in place, and there exists in the pharmaceutical industry and the regulatory agencies a significant amount of historical data for the rat. The resulting experience base with the rat makes the possibility of replacing it with the mouse for regulated toxicology studies untenable for all but the most extreme circumstances. However, toxicologists are very familiar with the mouse as a model for chronic carcinogenicity studies, and there exist multiple preclinical mouse models of disease. The authors evaluated the use of the mouse for early in vivo toxicology signal generation and prioritization of small molecule lead compounds prior to nomination of a development candidate. In five-day oral gavage studies with three test agents in the mouse, the authors were able to identify the same dose-limiting toxicities as those identified in the rat, including examples of compound-mediated hemolysis as well as microscopic lesions in the alimentary canal, kidney, and pancreas. Performing early signal generation studies in the mouse allows for earlier assessment of the safety liabilities of small molecules, requires significantly less compound, and allows evaluation of more compounds earlier in the project's life cycle.

Role of superoxide, nitric oxide, and peroxynitrite in doxorubicin-induced cell death in vivo and in vitro

Doxorubicin (DOX) is a potent available antitumor agent; however, its clinical use is limited because of its cardiotoxicity. Cell death is a key component in DOX-induced cardiotoxicity, but its mechanisms are elusive. Here, we explore the role of superoxide, nitric oxide (NO), and peroxynitrite in DOX-induced cell death using both in vivo and in vitro models of cardiotoxicity. Western blot analysis, real-time PCR, immunohistochemistry, flow cytometry, fluorescent microscopy, and biochemical assays were used to determine the markers of apoptosis/necrosis and sources of NO and superoxide and their production. Left ventricular function was measured by a pressure-volume system. We demonstrated increases in myocardial apoptosis (caspase-3 cleavage/activity, cytochrome c release, and TUNEL), inducible NO synthase (iNOS) expression, mitochondrial superoxide generation, 3-nitrotyrosine (NT) formation, matrix metalloproteinase (MMP)-2/MMP-9 gene expression, poly(ADP-ribose) polymerase activation [without major changes in NAD(P)H oxidase isoform 1, NAD(P)H oxidase isoform 2, p22(phox), p40(phox), p47(phox), p67(phox), xanthine oxidase, endothelial NOS, and neuronal NOS expression] and decreases in myocardial contractility, catalase, and glutathione peroxidase activities 5 days after DOX treatment to mice. All these effects of DOX were markedly attenuated by peroxynitrite scavengers. Doxorubicin dose dependently increased mitochondrial superoxide and NT generation and apoptosis/necrosis in cardiac-derived H9c2 cells. DOX- or peroxynitrite-induced apoptosis/necrosis positively correlated with intracellular NT formation and could be abolished by peroxynitrite scavengers. DOX-induced cell death and NT formation were also attenuated by selective iNOS inhibitors or in iNOS knockout mice. Various NO donors when coadministered with DOX but not alone dramatically enhanced DOX-induced cell death with concomitant increased NT formation. DOX-induced cell death was also attenuated by cell-permeable SOD but not by cell-permeable catalase, the xanthine oxidase inhibitor allopurinol, or the NADPH oxidase inhibitors apocynine or diphenylene iodonium. Thus, peroxynitrite is a major trigger of DOX-induced cell death both in vivo and in vivo, and the modulation of the pathways leading to its generation or its effective neutralization can be of significant therapeutic benefit.

Activation of inducible NOS in peripheral vessels and outcomes in heart failure patients

BACKGROUND

Activation of inducible nitric oxide synthase (iNOS) has been reported in congestive heart failure (CHF) conditions. However, it is unknown whether activation of iNOS affects prognosis of CHF patients. We prospectively studied the influence of activation of iNOS in the forearm on the outcome of CHF patients.

METHODS AND RESULTS

Forearm blood flow (FBF) responses to 3 doses of acetylcholine (ACh) and nitroglycerin (NTG), and 4 doses of a selective iNOS inhibitor (aminoguanidine: Amn) and a nonselective NOS inhibitor (L-NMMA) were examined using plethysmography in 68 patients with CHF from idiopathic dilated cardiomyopathy. Plasma brain natriuretic peptide (BNP) and tumor necrosis factor-alpha (TNF-alpha) were also measured in all patients. During the mean follow-up period of 3.8 years, 25 patients were hospitalized for worsening heart failure and 9 of these patients died. Patients with adverse events had a diminished vasodilator response to ACh (P < .001) compared to patients without adverse events. Amn significantly decreased FBF (P < .001) in patients with adverse events, but not in patients without adverse events. FBF responses to NTG and L-NMMA were not significantly different between the 2 groups. When grouped by maximum FBF responses to each drug above and below the median value, multivariate Cox proportional hazards model analyses for cardiac event showed a significance in the FBF response to Amn (adjusted hazard ratio 5.89, P < .001). FBF responses to maximum dose of Amn significantly correlated with BNP and TNF-alpha levels (both P < .001).

CONCLUSIONS

CHF patients with vascular iNOS activation, as demonstrated by a greater vasoconstrictor response to Amn, had poor outcomes. Activation of iNOS in peripheral vessels, associated with proinflammatory cytokines in accordance to the severity of heart failure, is a marker for, or contributes to, adverse events in patients with CHF.

Protective effects of melatonin on renal failure in pinealectomized rats

AIM

The purpose of the current study was to investigate the effects melatonin on renal function.

METHODS

The histological appearance of the kidney and malondialdehyde, nitric oxide, glutathione and superoxide dismutase contents were determined. Serum creatinine and blood urea nitrogen levels were also assayed. Rats were divided as: Sham, pinealectomized (Px) and pinealectomized and treated with melatonin.

RESULTS

In Px group, malondialdehyde and nitric oxide levels were elevated when compared with the sham group. The Px group exhibited reduced superoxide dismutase activity and glutathione content. All of these harmful changes were restored by melatonin. Melatonin also ameliorated serum creatinine and blood urea nitrogen levels related to renal injury. The score for glomerular, tubular and interstitial changes was significantly higher in the Px group. Melatonin supplementation significantly reduced these parameters.

CONCLUSIONS

This protective effect may be associated with both melatonin's lipophilic and hydrophilic effects, thus providing on-site protection against free radical mediated damage.

Protective role of aminoguanidine on gentamicin-induced acute renal failure in rats

The toxicity of aminoglycosides including gentamicin (GEN), the most widely used drug in this category, is believed to be related to the generation of reactive oxygen species (ROS) in the kidney. Aminoguanidine (AG) is known as an effective antioxidant and its free radical scavenger effects may protect GEN-induced acute renal failure (ARF). Therefore, this study was focused on investigating the possible protective effect of AG against GEN-induced nephrotoxicity in an in vivo rat model. We investigated the effects of AG on GEN-induced changes in renal tissue malondialdehyde (MDA) levels; nitric oxide (NO) generation; glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities; glutathione (GSH) content; serum creatinine (Cr) and blood urea nitrogen (BUN) levels. Morphological changes in the kidney were also examined using light microscopy. GEN administration to control group rats increased renal MDA and NO levels but decreased GSH-Px, SOD, CAT activities and GSH content. AG administration with GEN injection resulted in significantly decreased MDA, NO generation and increased GSH-Px, SOD, CAT activities and GSH content when compared with GEN alone. Serum levels of Cr and BUN significantly increased as a result of nephrotoxicity. Also, AG significantly decreased Cr and BUN levels. Morphological changes in the kidney, including tubular necrosis, intracellular edema, glomerular and basement membrane alterations were evaluated qualitatively. Both biochemical findings and histopathological evidence showed that administration of AG reduced the GEN-induced kidney damage. We propose that AG acts in the kidney as a potent scavenger of free radicals to prevent the toxic effects of GEN both at the biochemical and histological level.