Role of ATP-Sensitive Potassium Channel (KATP) and eNOS in Mediating the Protective Effect of Nicorandil in Cyclophosphamide-Induced Cardiotoxicity

Acetate attenuates cyclophosphamide-induced cardiac injury via inhibition of NF-kB signaling and suppression of caspase 3-dependent apoptosis in Wistar rats

AIM

The goal of the current study was to examine the potential therapeutic effects of sodium acetate on cardiac toxicities caused by cyclophosphamide in Wistar rats. The possible involvement of NF-kB/caspase 3 signaling was also explored.

MAIN METHODS

Thirty-two male Wistar rats were divided into four groups at random. (n = 8). The control animals received 0.5 mL of distilled water orally for 14 days, the acetate-treated group received 200 mg/kg/day of sodium acetate orally for 14 consecutive days, and cyclophosphamide-treated rats received 150 mg/kg /day of cyclophosphamide i.p. on day 8, while cyclophosphamide + acetate group received sodium acetate and cyclophosphamide as earlier stated.

KEY FINDINGS

Results showed that cyclophosphamide-induced cardiotoxicity, which manifested as a marked drop in body and cardiac weights as well as cardiac weight/tibial length, increased levels of troponin, C-reactive protein, lactate, and creatinine kinase, and lactate dehydrogenase activities in the plasma and cardiac tissue. Histopathological examination also revealed toxic cardiac histopathological changes. These alterations were associated with a significant increase in xanthine oxidase and myeloperoxidase activities, uric acid, malondialdehyde, TNF-α, IL-1β, NFkB, DNA fragmentation, and caspase 3 and caspase 9 activities in addition to a marked decline in Nrf2 and GSH levels, and SOD and catalase activities in the cardiac tissue. Acetate co-administration significantly attenuated cyclophosphamide cardiotoxicity by its antioxidant effect, preventing NFkB activation and caspase 9/caspase 3 signalings.

SIGNIFICANCE

This study shows that acetate co-administration may have cardio-protective effects against cyclophosphamide-induced cardiotoxicity by inhibiting NF-kB signaling and suppressing caspase-3-dependent apoptosis.

Curcumin mitigates gentamicin induced-renal and cardiac toxicity via modulation of Keap1/Nrf2, NF-κB/iNOS and Bcl-2/BAX pathways

Gentamicin (GEN) is an aminoglycoside antibiotic used to treat gram-negative bacterial infections. Our study aimed to explore curcumin's (CMN) protective role against GEN-induced renal and cardiac toxicity. Rats were randomly classified into 4 equal groups; Control (cont), GEN (100 mg/kg b.wt, i.p.) for seven days, CMN (200 mg/kg b.wt, orally) for 21 days, and CMN + GEN groups. GEN caused renal and cardiac dysfunctions; increased urea, creatinine, uric acid, cystatin C, CK-MB, LDH, and troponin I serum levels. MDA level was elevated significantly while activities of SOD, CAT, and GSH level were reduced significantly in renal and cardiac tissues. GEN-intoxicated rats showed up-regulation of NF-κB, IL-1β, Keap1, HMOX1, and BAX with down-regulation of Nrf2, and Bcl-2 mRNA expression in renal and cardiac tissues. Also, GEN-induced up-regulation of renal mRNA expression of KIM-1, NGAL, and intermediate filament proteins [desmin, nestin, and vimentin] as well cardiac gene expression of cMyBP-C and H-FABP. GEN-induced toxicity was significantly attenuated by CMN co-treatment as CMN improved renal and cardiac biomarkers, reduced oxidative stress and inflammatory response, and reversed alterations in mRNA expression of all tested renal and cardiac genes. These outcomes indicated that CMN could protect renal and cardiac tissues against GEN-induced oxidative stress, inflammation, and apoptosis.

Selenium protection from DNA damage and regulation of apoptosis signaling following cyclophosphamide induced cardiotoxicity in rats

We investigated the mechanism of the cardioprotective effect of selenium (Se) against cyclophosphamide (CPA) induced cardiotoxicity in rats. We divided 24 female Wistar albino rats into four groups. The control group was injected intraperitoneally (i.p.) with normal saline. The CPA group was injected i.p. with 200 mg/kg CPA. The Se group was injected i.p. with 1 mg/kg Se. The CPA + Se group was injected i.p. with 200 mg/kg CPA and 1 mg/kg Se. Rats were euthanized 24 h after injection and heart tissues were harvested. Histopathological examination revealed reduced severity of myocardial lesions in the CPA + Se group compared to CPA induced cardiotoxicity of the CPA group; this finding was confirmed by increased immunoreactivity of cardiac troponin-I (cTn-I) in the CPA + Se group compared to decreased cTn-I immunoreactivity in the CPA group. Administration of CPA increased the immunoreactivity of phosphorylated histone-2AX (γH2AX). Se reduced the CPA induced increase in γH2AX immunoreactivity. Se administration reversed the CPA induced increase of Bax and decrease of Bcl2 gene expressions. Our findings suggest that Se is cardioprotective by reducing DNA damage and regulating the genes responsible for apoptosis caused by CPA in rats.

Effects of nicorandil on QT prolongation and myocardial damage caused by citalopram in rats

Citalopram is a selective serotonin re-uptake inhibitor (SSRI) antidepressant; it exhibits the greatest cardiotoxic effect among SSRIs. Citalopram can cause drug-induced long QT syndrome (LQTS) and ventricular arrhythmias. We investigated the protective effect of nicorandil, a selective mitochondrial KATP (mito-KATP) channel opener, on LQTS and myocardial damage caused by citalopram in male rats. In a preliminary study, we determined that the minimum citalopram dose that prolonged the QT interval was 102 mg/kg injected intraperitoneally. For the main study, rats were divided randomly into five experimental groups: untreated control, normal saline + citalopram, nicorandil + citalopram, 5-hydroxydecanoate (5-HD) + citalopram, 5-HD + nicorandil + citalopram. Biochemical and histologic data from blood and heart tissue samples from six untreated control rats were evaluated. Electrocardiographic parameters including QRS duration, QT interval, corrected QT interval (QTc) and heart rate (HR) were assessed, and biochemical parameters including malondialdehyde, reduced glutathione, glutathione peroxidase, superoxide dismutase were measured. We also performed histomorphologic and immunohistochemical examination of heart tissue. Citalopram prolonged QT-QTc intervals significantly and increased significantly the histomorphologic score and proportion of apoptotic cells, but produced no differences in the oxidant and antioxidant parameters. Nicorandil did not prevent citalopram induced QT-QTc interval prolongation and produced no significant changes in oxidant and antioxidant parameters; however, it did reduce histologic damage and apoptosis caused by citalopram.

Revisiting treatment-related cardiotoxicity in patients with malignant lymphoma-a review and prospects for the future

Treatment of malignant lymphoma has for years been represented by many cardiotoxic agents especially anthracyclines, cyclophosphamide, and thoracic irradiation. Although they are in clinical practice for decades, the precise mechanism of cardiotoxicity and effective prevention is still part of the research. At this article we discuss most routinely used anti-cancer drugs in chemotherapeutic regiments for malignant lymphoma with the focus on novel insight on molecular mechanisms of cardiotoxicity. Understanding toxicity at molecular levels may unveil possible targets of cardioprotective supportive therapy or optimization of current therapeutic protocols. Additionally, we review novel specific targeted therapy and its challenges in cardio-oncology.

Cardiotoxicity in autologous haematopoietic stem cell transplantation for systemic sclerosis

Autologous haematopoietic stem cell transplantation is now well-established as an effective treatment for severe systemic sclerosis with clear demonstration of favourable end-organ and survival outcomes. Treatment-related cardiotoxicity remains the predominant safety concern and contraindicates autologous haematopoietic stem cell transplantation in patients with severe cardiopulmonary disease. In this review, we describe the cardiovascular outcomes of autologous haematopoietic stem cell transplantation recipients, discuss the potential mechanisms of cardiotoxicity and propose future mitigating strategies.

Effect of the selective mitochondrial KATP channel opener nicorandil on the QT prolongation and myocardial damage induced by amitriptyline in rats

OBJECTIVES

The aim of this study is to evaluate the protective effect of nicorandil, a selective mitochondrial KATP channel opener, on QT prolongation and myocardial damage induced by amitriptyline.

METHODS

The dose of amitriptyline (intraperitoneal, i.p.) that prolong the QT interval was found 75 mg/kg. Rats were randomized into five groups the control group, amitriptyline group, nicorandil (selective mitochondrial KATP channel opener, 3 mg/kg i.p.) + amitriptyline group, 5-hdyroxydecanoate (5-HD, selective mitochondrial KATP channel blocker, 10 mg/kg i.p.) + amitriptyline group and 5-HD + nicorandil + amitriptyline group. Cardiac parameters, biochemical and histomorphological/immunohistochemical examinations were evaluated. p < 0.05 was accepted as statistically significant.

KEY FINDINGS

Amitriptyline caused statistically significant prolongation of QRS duration, QT interval and QTc interval (p < 0.05). It also caused changes in tissue oxidant (increase in malondialdehyde)/anti-oxidant (decrease in glutathione peroxidase) parameters (p < 0.05), myocardial damage and apoptosis (p < 0.01 and p < 0.001). While nicorandil administration prevented amitriptyline-induced QRS, QT, QTc prolongation (p < 0.05), myocardial damage and apoptosis (p < 0.05), it did not affect the changes in oxidative parameters (p > 0.05).

CONCLUSIONS

Our results suggest that nicorandil, a selective mitochondrial KATP channel opener, plays a protective role in amitriptyline-induced QT prolongation and myocardial damage. Mitochondrial KATP channel opening and anti-apoptotic effects may play a role in the cardioprotective effect of nicorandil.

Cell death regulation in myocardial toxicity induced by antineoplastic drugs

Homeostatic regulation of cardiomyocytes plays a critical role in maintaining normal physiological activity of cardiac tissue. Severe cardiotoxicity can lead to heart disease, including but not limited to arrhythmias, myocardial infarction and cardiac hypertrophy. In recent years, significant progress has been made in developing new therapies for cancer that have dramatically changed the treatment of several malignancies and continue to improve patient survival, but can also lead to serious cardiac adverse effects. Mitochondria are key organelles that maintain homeostasis in myocardial tissue and have been extensively involved in various cardiovascular disease episodes, including ischemic cardiomyopathy, heart failure and stroke. Several studies support that mitochondrial targeting is a major determinant of the cardiotoxic effects triggered by chemotherapeutic agents increasingly used in solid and hematologic tumors. This antineoplastic therapy-induced mitochondrial toxicity is due to different mechanisms, usually altering the mitochondrial respiratory chain, energy production and mitochondrial kinetics, or inducing mitochondrial oxidative/nitrosative stress, ultimately leading to cell death. This review focuses on recent advances in forms of cardiac cell death and related mechanisms of antineoplastic drug-induced cardiotoxicity, including autophagy, ferroptosis, apoptosis, pyroptosis, and necroptosis, explores and evaluates key proteins involved in cardiac cell death signaling, and presents recent advances in cardioprotective strategies for this disease. It aims to provide theoretical basis and targets for the prevention and treatment of pharmacological cardiotoxicity in clinical settings.

Role of hypoxia inducible factor/vascular endothelial growth factor/endothelial nitric oxide synthase signaling pathway in mediating the cardioprotective effect of dapagliflozin in cyclophosphamide-induced cardiotoxicity

BACKGROUND

Cyclophosphamide (CP) is a commonly used chemotherapeutic and immunosuppressive alkylating agent. However, cardiac adverse effects of CP interfere with its clinical benefit. Cardio-oncology research is currently an important issue and finding effective cardiopreserving agents is a critical need. For the first time, we aimed to detect if dapagliflozin (DAP) could ameliorate CP-induced cardiac injury and investigated the role of hypoxia inducible factor α (HIF1α)/vascular endothelial growth factor (VEGF)/endothelial nitric oxide synthase (eNOS) pathway.

METHODS

Forty male Wistar albino rats were included in the current model. Studied groups are: control group; CP-induced cardiotoxicity group; CP group treated with DAP; CP group treated with DAP and administered a nitric oxide synthase inhibitor; nitro-ω-L-arginine (L-NNA) before DAP to explore the role of eNOS.

RESULTS

Our data revealed that CP could induce cardiac damage as manifested by significant increases in cardiac enzymes, blood pressure, malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), HIF1α, sodium glucose co-transporter 2 (SGLT2) and cleaved caspase-3 levels with toxic histopathological changes. However, there are significant decreases in reduced glutathione (GSH), total antioxidant capacity (TAC), VEGF, and eNOS. On the opposite side, co-administration of DAP showed marked improvement of CP-induced cardiac damage that may be due to its ability to inhibit SGLT2, antioxidant, anti-inflammatory and anti-apoptotic properties. Results showed decreasing the cardioprotective effect of DAP on administration of L-NNA, reflecting the critical effect of eNOS in mediating such protection.

CONCLUSION

DAP could reduce CP cardiotoxicity based upon its ability to modulate SGLT2 and HIF1α/VEGF/eNOS signaling pathway.

Cardiovascular Complications in Hematopoietic Stem Cell Transplanted Patients

Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for many patients suffering from hematologic malignancies, solid tumors, inborn errors of metabolism or genetic disorders. Despite decades of successful HSCT, clinical outcomes are still far from satisfactory due to treatment-related complications, including graft-versus-host disease (GvHD) and cardiovascular complications (CVC). CVC may affect patients in the acute period post-HSCT; however, the occurrence is far higher among long-term survivors. Induction treatment using cardiotoxic treatments, e.g., anthracyclines and radiotherapy, conditioning regimens containing cyclophosphamide, and post-HSCT comorbidities, including GvHD, are factors contributing to CVC. Cardiac function evaluation prior to and post-transplantation is an important strategy for choosing the proper conditioning regimen, HSCT protocol and post-HSCT supportive care. Cardiac systolic function evaluation by echocardiography, in addition to serum cardiac biomarkers, such as troponins and brain natriuretic peptides, is recommended as a routine follow-up for HSCT patients. Angiotensin-converting enzyme inhibitors, angiotensin-II-receptor blockers, and beta-blockers, which are mostly used for the treatment of chemotherapy-induced cardiotoxicity, might be used as treatments for HSCT-related CVC. In summary, the present review reveals the urgent need for further investigations concerning HSCT-related CVC both at the preclinical and clinical levels due to the lack of knowledge about CVC and its underlying mechanisms.

Simvastatin cardioprotection in cyclophosphamide-induced toxicity via the modulation of inflammasome/caspase1/interleukin1β pathway

Drug-induced cardiotoxicity is a serious adverse effect that occurs during the administration of chemotherapeutic agents such as cyclophosphamide (CYC). Therefore, there is a critical need to find cardioprotective agents to keep the heart healthy. The current study aimed to investigate the protective effect of simvastatin (SIM) against CYC-induced heart damage and evaluate different mechanisms involved in mediating this effect, including the inflammasome/caspase1/interleukin1β (IL1β) pathway and endothelial nitric oxide synthase (eNOS). 36 rats were randomly assigned to one of four groups: a control group that received only vehicles, a CYC group that received CYC (150 mg/kg/day) i.p. on the fourth and fifth days, a CYC+SIM group that received SIM (10 mg/kg/day) orally for 5 days and CYC (150 mg/kg/day) i.p. on the fourth and fifth days, and a CYC+SIM+ Nitro- ω-L-arginine (L-NNA) group that received L-NNA (25 mg/kg/day, SIM (10 mg/kg/day) orally for 5 days and CYC (150 mg/kg/day) i.p. on the 4th and 5th days. The CYC group revealed an obvious elevation in cardiac enzymes and heart weights with toxic histopathological changes. Moreover, there was an increase in malondialdehyde (MDA), tumor necrosis factor-alpha (TNFα) levels, and up-regulation of the NLRP3inflammasome/caspase1/IL1β pathway. In addition, total antioxidant capacity (TAC), eNOS, reduced glutathione (GSH), and superoxide dismutase (SOD) significantly decreased. CYC-induced cardiotoxicity was most properly reversed by SIM through its anti-oxidant, anti-inflammatory, and anti-apoptotic actions with the stimulation of eNOS. The co-administration of L-NNA diminished the protective effect of SIM, indicating the essential role of eNOS in mediating this effect. Therefore, SIM ameliorated CYC-induced cardiotoxicity.

The Clinical Value of Chemotherapy Combined With Capecitabine in Triple-Negative Breast Cancer-A Meta-Analysis

Purpose: Triple-negative breast cancer (TNBC) is the most dangerous subtype of breast cancer with high rates of metastasis and recurrence. The efficacy of capecitabine in chemotherapy for TNBC is still controversial. This study evaluated the efficacy and safety of capecitabine combining with standard, adjuvant or neoadjuvant chemotherapy for TNBC.

Methods: We systematically searched clinical studies through PubMed, Cochrane library, Embase, Wanfang Database, China Academic Journals (CNKI), and American Society of Clinical Oncology’s (ASCO) annual conference report. Studies were assessed for design and quality by the Cochrane risk of bias tool. A meta-analysis was performed using Review Manager to quantify the effect of capecitabine combined with standard, adjuvant or neoadjuvant chemotherapy on the disease-free survival (DFS) rate and overall survival (OS) rate of TNBC patients. Furthermore, safety analysis was performed to evaluate the adverse events.

Results: Twelve randomized controlled clinical trials involving totally 4854 TNBC patients were included, of which 2,214 patients received chemotherapy as control group, and 2,278 patients received capecitabine combining with chemotherapy. The results indicated that capecitabine could significantly improve the DFS [hazard ratio (HR) 0.80, 95% confidence interval (CI) 0.71–0.90, P = 0.0003] and OS (HR 0.83, 95% CI 0.74–0.93, P = 0.001). In subgroup analysis, the combination of capecitabine and cyclophosphamide exhibited a significant benefit in all outcomes (DFS HR 0.75, 95% CI 0.63–0.90, P = 0.002; OS HR 0.65, 95% CI 0.52–0.80, p < 0.0001). Additionally, defferent dose of capecitabine subgroup showed same significant effect on the results. Safety analysis showed that the addition of capecitabine was associated with a much higher risk of hand-foot syndrome, diarrhea and mucositis or stomatitis.

Conclusion: The results showed that adjuvant capecitabine could bring significant benefits on DFS and OS to unselected TNBC patients, the combination of capecitabine and cyclophosphamide could improve the survival rate of patients, although the addition of capecitabine could bring significant side effects such as hand foot syndrome (HFS) and diarrhea.

Dose-Dependent Cardioprotective Effect of Hemin in Doxorubicin-Induced Cardiotoxicity Via Nrf-2/HO-1 and TLR-5/NF-κB/TNF-α Signaling Pathways

Doxorubicin (DOX) is one of the most widely used chemotherapeutic drugs, but its cardiotoxicity has been shown to be a dose-restricting factor during therapy. Finding new agents for reducing these complications is still in critical need. The current study aimed to evaluate the possible cardioprotective effect of hemin (HEM) in DOX-induced cardiotoxicity and exploring the role of toll like receptor-5/nuclear factor kappa-B/tumor necrosis factor-alpha (TLR-5/NF-κB/TNF-α) and nuclear factor erythroid 2-related factor-2/hemeoxygenase-1 (Nrf-2/HO-1) signaling pathways in mediating such effect. Wistar albino rats were randomly divided into five groups. They were administered DOX by interaperitoneal (i.p.) injection (15 mg/kg) on the 5th day of the experiment with or without HEM in different doses (2.5, 5, 10 mg/kg/day) i.p. for 7 days. Results showed that the DOX group had cardiotoxicity as manifested by a significant increase in cardiac enzymes, malondialdehyde (MDA), TLR-5, NF-κB, TNF-α, and cleaved caspase-3 levels with toxic histopathological changes. Based on these findings, HEM succeeded in reducing DOX-induced cardiotoxicity in a dose-dependent effect by stimulation of Nrf-2/HO-1 and inhibition of TLR-5/NF-κB/TNF-α pathways with subsequent antioxidant, anti-inflammatory, and anti-apoptotic effects.

Effect of a Low Dose of Carvedilol on Cyclophosphamide-Induced Urinary Toxicity in Rats—A Comparison with Mesna

One of the major side effects of cyclophosphamide (CPX)—an alkylating anticancer drug that is still clinically used—is urotoxicity with hemorrhagic cystitis. The present study was designed to evaluate the ability of carvedilol to protect rats from cyclophosphamide-induced urotoxicity. Rats were injected intraperitoneally (i.p.) with CPX (200 mg/kg) and administered carvedilol (2 mg/kg) intragastrically a day before, at the day and a day after a single i.p. injection of CPX, with or without mesna (40, 80, and 80 mg/kg i.p. 20 min before, 4 h and 8 h after CPX administration, respectively). Pretreatment with carvedilol partly prevented the CPX-induced increase in urinary bladder and kidney index, and completely protects from CPX-evoked alterations in serum potassium and creatinine level, but did not prevent histological alterations in the urinary bladder and hematuria. However, carvedilol administration resulted in significant restoration of kidney glutathione (GSH) level and a decrease in kidney interleukin 1β (IL-1β) and plasma asymmetric dimethylarginine (ADMA) concentrations. Not only did mesna improve kidney function, but it also completely reversed histological abnormalities in bladders and prevented hematuria. In most cases, no significant interaction of carvedilol with mesna was observed, although the effect of both drugs together was better than mesna given alone regarding plasma ADMA level and kidney IL-1β concentration. In conclusion, carvedilol did not counteract the injury caused in the urinary bladders but restored kidney function, presumably via its antioxidant and anti-inflammatory properties.

Protective effect of Apelin-13 in a cyclophosphamide-induced cardiorenal toxicity model in rats

Cyclophosphamide is a chemotherapeutic drug that is widely used in the clinic and can cause multi-organ toxicity. Apelin-13 is an endogenous adipocytokine with antioxidant properties. Therefore, this study aimed to investigate the possibility of apelin-13 being a potential therapeutic agent on cardiac toxicity and nephrotoxicity caused by cyclophosphamide. In this study, a total of 4 groups were formed, including 8 rats in each group. Group 1: The control group was administered only saline (ip). Group 2: Cyclophosphamide, a single dose of 200 mg/kg (ip) on day 7. Group 3: Apelin-13 (15 μg/kg), for 7 days (ip). Group 4: Administering apelin-13 (15 μg/kg) (ip) for 7 days and a single dose of cyclophosphamide (200 mg/kg) (ip) on day 7, the rats were sacrificed on day 8. LDH, cTn1, cK-Mb, AST, ALT, ALP, MDA, creatinine, and BUN were found to be high in the cyclophosphamide group, however, these values were reduced with apelin-13 administration. Antioxidant enzymes such as SOD, GPx, CAT, and GSH decreased in the cyclophosphamide group, apelin-13 increased these enzyme activities. In addition, histopathological examinations also supported the results obtained. The findings of this study showed that apelin-13 has a protective effect against cardiorenal toxicity caused by cyclophosphamide.

Astaxanthin extenuates the inhibition of aldehyde dehydrogenase and Klotho protein expression in cyclophosphamide-induced acute cardiomyopathic rat model

This study evaluated the mechanistic sequel of aldehyde dehyrogenase (ALDH2) and Klotho protein in cyclophosphamide (CP)-induced cardiotoxicity in rats and the protective effect of astaxanthin (AST) against that sequel. A total of 40 male Wistar albino rats were divided into four groups of 10 animals each: Group 1 was injected intraperitoneally (i.p.) with normal saline for 10 successive days. Group 2 was injected with normal saline for 5 days before and after a single dose of CP (200 mg/kg, i.p.). Group 3 received AST (50 mg/kg/day, i.p.) for 10 days. Group 4 received CP as group 2 and AST as group 3. After the last dose of the treatment protocol, serum was separated to measure cardiotoxicity indices and the left ventricle was then dissected for mRNA and protein expression studies and histopathological examinations. Treatment with CP significantly increased serum lactate dehydrogenase (LDH), creatine kinase isoenzyme MB (CK-MB), and troponin, while significantly decreased soluble α Klotho protein and caused histopathological lesions in cardiac tissues. In cardiac tissues, CP significantly decreased gene expression of ALDH2, Klotho protein, mTOR, IGF, AKT, AMPK, BCL2, but significantly increased expression of BAX and caspase-8. Interestingly, administration of AST in combination with CP completely reversed all the biochemical, histopathological and gene expression changes induced by CP to the control values. The current study suggests that inhibition of ALDH2, Klotho protein, mTOR, and AMPK signals in cardiac tissues may contribute to CP-induced acute cardiomyopathy. AST supplementation attenuates CP-induced cardiotoxicity by modulating ALDH2 and Klotho protein expression in heart tissues, along with its downstream apoptosis effector markers.

Anticancer Drug-Induced Cardiotoxicity: Insights and Pharmacogenetics

The advancement in therapy has provided a dramatic improvement in the rate of recovery among cancer patients. However, this improved survival is also associated with enhanced risks for cardiovascular manifestations, including hypertension, arrhythmias, and heart failure. The cardiotoxicity induced by chemotherapy is a life-threatening consequence that restricts the use of several chemotherapy drugs in clinical practice. This article addresses the prevalence of cardiotoxicity mediated by commonly used chemotherapeutic and immunotherapeutic agents. The role of susceptible genes and radiation therapy in the occurrence of cardiotoxicity is also reviewed. This review also emphasizes the protective role of antioxidants and future perspectives in anticancer drug-induced cardiotoxicities.

The IL-6/STAT Signaling Pathway and PPARα Are Involved in Mediating the Dose-Dependent Cardioprotective Effects of Fenofibrate in 5-Fluorouracil-Induced Cardiotoxicity

PURPOSE

The cardiotoxicity of anticancer drugs such as 5-fluorouracil (5FU) is a major complication that challenges their clinical usefulness. Thus there is a critical need to find new protective drugs to defend against these harmful side effects. Up to now, there have been no studies evaluating the possible cardioprotective effects of fenofibrate (FEN) in 5FU-induced cardiotoxicity. Therefore, we aimed in the current model to evaluate such an effect of FEN and to explore different mechanisms mediating it.

METHODS

We used FEN (25, 50, 100 mg/kg/day) administered orally for 7 days with induction of cardiotoxicity by intraperitoneal (i.p.) injection of 5FU (150 mg/kg) on the fifth day.

RESULTS

The current study showed that 5FU succeeded in inducing cardiotoxicity, manifested by significantly elevated levels of cardiac enzymes, tissue malondialdehyde (MDA), interleukin 6 (IL-6), signal transducer and activator of transcription 4 (STAT4), and caspase-3. Furthermore, the 5FU group showed toxic histopathological changes including marked cardiac damage and a significant decrease in reduced glutathione (GSH), total antioxidant capacity (TAC), and peroxisome proliferator-activated receptor alpha (PPARα) expression. FEN reversed 5FU-induced cardiotoxicity by various mechanisms including upregulation of PPARα, inhibition of the IL-6/STAT signaling pathway, and anti-inflammatory, antiapoptotic, and antioxidant properties.

CONCLUSION

FEN demonstrated a significant cardioprotective effect against 5FU-induced cardiac damage.

Effects of anticancer drugs on the cardiac mitochondrial toxicity and their underlying mechanisms for novel cardiac protective strategies

Mitochondria are organelles that play a pivotal role in the production of energy in cells, and vital to the maintenance of cellular homeostasis due to the regulation of many biochemical processes. The heart contains a lot of mitochondria because those muscles require a lot of energy to keep supplying blood through the circulatory system, implying that the energy generated from mitochondria is highly dependent. Thus, cardiomyocytes are sensitive to mitochondrial dysfunction and are likely to be targeted by mitochondrial toxic drugs. It has been reported that some anticancer drugs caused unwanted toxicity to mitochondria. Mitochondrial dysfunction is related to aging and the onset of many diseases, such as obesity, diabetes, cancer, cardiovascular and neurodegenerative diseases. Mitochondrial toxic mechanisms can be mainly explained concerning reactive oxygen species (ROS)/redox status, calcium homeostasis, and endoplasmic reticulum stress (ER) stress signaling. The toxic mechanisms of many anticancer drugs have been revealed, but more studying and understanding of the mechanisms of drug-induced mitochondrial toxicity is required to develop mitochondrial toxicity screening system as well as novel cardioprotective strategies for the prevention of cardiac disorders of drugs. This review focuses on the cardiac mitochondrial toxicity of commonly used anticancer drugs, i.e., doxorubicin, mitoxantrone, cisplatin, arsenic trioxide, and cyclophosphamide, and their possible chemopreventive agents that can prevent or alleviate cardiac mitochondrial toxicity.

Nicorandil mitigates folic acid-induced nephrotoxicity in mice: Role of iNOS and eNOS

Folic acid (FA)-induced acute kidney injury (AKI) is a commonly used model in experimental animals for studying renal injury. This study aimed to investigate the probable protecting impact of nicorandil against FA-induced renal dysfunction. A mouse model was executed by a single injection of FA (250 mg/kg). Nicorandil was orally administrated in two doses (50 and 100 mg/kg) for 10 days. Nicorandil repressed the progression of FA-induced AKI as evidenced by the improvement of histopathological alterations and the substantial decrease of serum levels of creatinine, urea, blood urea nitrogen, malondialdehyde (MDA), and urinary protein levels. Moreover, nicorandil resulted in a profound reduction in oxidative stress as manifested by decreased MDA and increased reduced glutathione and superoxide dismutase in renal tissue. Notably, nicorandil suppressed FA-induced inflammation; it reduced renal levels of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, nicorandil decreased renal levels of nitric oxide, inducible nitric oxide synthase, and increased endothelial nitric oxide synthase. Lastly, nicorandil efficiently decreased expression of the proapoptotic protein (Bax) and caspase 3. Nicorandil confers dose-dependent protection against FA-induced AKI by alleviating oxidative stress, inflammation besides modulating nitric oxide synthase and reducing apoptosis.

Molecular Mechanisms of Cardiomyocyte Death in Drug-Induced Cardiotoxicity

Homeostatic regulation of cardiomyocytes plays a crucial role in maintaining the normal physiological activity of cardiac tissue. Severe cardiotoxicity results in cardiac diseases including but not limited to arrhythmia, myocardial infarction and myocardial hypertrophy. Drug-induced cardiotoxicity limits or forbids further use of the implicated drugs. Such drugs that are currently available in the clinic include anti-tumor drugs (doxorubicin, cisplatin, trastuzumab, etc.), antidiabetic drugs (rosiglitazone and pioglitazone), and an antiviral drug (zidovudine). This review focused on cardiomyocyte death forms and related mechanisms underlying clinical drug-induced cardiotoxicity, including apoptosis, autophagy, necrosis, necroptosis, pryoptosis, and ferroptosis. The key proteins involved in cardiomyocyte death signaling were discussed and evaluated, aiming to provide a theoretical basis and target for the prevention and treatment of drug-induced cardiotoxicity in the clinical practice.

The Role of Antioxidants in Ameliorating Cyclophosphamide-Induced Cardiotoxicity

The chemotherapeutic and immunosuppressive agent cyclophosphamide has previously been shown to induce complications within the setting of bone marrow transplantation. More recently, cardiotoxicity has been shown to be a dose-limiting factor during cyclophosphamide therapy, and cardiooncology is getting wider attention. Though mechanism of cyclophosphamide-induced cardiotoxicity is not completely understood, it is thought to encompass oxidative and nitrative stress. As such, this review focuses on antioxidants and their role in preventing or ameliorating cyclophosphamide-induced cardiotoxicity. It will give special emphasis to the cardioprotective effects of natural, plant-derived antioxidants that have garnered significant interest in recent times.