Cardioprotective effects of zofenopril, a new angiotensin-converting enzyme inhibitor, on doxorubicin-induced cardiotoxicity in the rat

The Protective Effect of Lasia spinosa (Linn.) Dissipates Chemical-Induced Cardiotoxicity in an Animal Model

Lasia spinosa (L.) Thwaites is a medicinal plant of enormous traditional use with insufficient scientific evidence. This research screened the antioxidative effect of L. spinosa extracts by measuring the total phenolic content, total flavonoid content, DPPH free radical scavenging activity, ABTS scavenging activity, Iron-chelating activity, and Ferric reducing power followed by an evaluation of in vivo cardioprotective effect in doxorubicin-induced Wistar Albino rats. Phytochemical characterization was made by Gas Chromatography-Mass Spectroscopic analysis. L. spinosa showed an excellent antioxidative effect while methanol leaf extract (LSM) was found to be more potent than ethyl acetate leaf extract (LSE) in scavenging the free radicals. Intraperitoneal injection of doxorubicin caused a significant (P < 0.001) increase in lactate dehydrogenase (LDH), creatine kinase (CK-MB), C-reactive protein (CRP), and Cardiac troponin I. Pretreatment with orally administrated (LSM100 and LSM200 mg/kg b.w.) daily for 10 days showed a decrease in the cardiac markers, lipid profiles, especially triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and an increase of high-density lipoprotein (HDL) compared to the disease control group. LSM200 was found to significantly (P < 0.05) decrease the levels of CK-MB and LDH. It also restored TC, TG, and LDL levels compared to the doxorubicin-induced cardiac control group. The protective role of LSM was further confirmed by histopathological examination. This study thus demonstrates that L. spinosa methanol extract could be approached as an alternative supplement for cardiotoxicity, especially in the chemical-induced toxicity of cardiac tissues.

Evaluation of Ameliorative Effect of Quercetin and Candesartan in Doxorubicin-Induced Cardiotoxicity

BACKGROUND

Several mechanisms have been explored for the anthracycline myocardial toxicity. These are free-radical generation, myocyte apoptosis, lipid peroxidation, mitochondrial deterioration, and direct repression of muscle-specific gene expression. Adriamycin (Doxorubicin) is a potent anti-cancer agent. Adriamycin in prolonged use is fatal and generates free radicals that lead to dose-dependent cardiac toxicity.

OBJECTIVE

The intent of the study was to explore the protective activity of candesartan and quercetin in cardiomyopathy induced by doxorubicin in rats.

METHODS

To induce cardiac toxicity, rats were intraperitoneally treated with doxorubicin (06 equivalent injections of 2.5 mg/kg, i. p. at 48 hour interval for 02 consecutive weeks to achieve a cumulative dose of 15 mg/kg). Individual and combined oral treatment of candesartan (5 mg/kg/day) and quercetin (10 mg/kg/day) was administered for four weeks.

RESULTS

Following cardiomyopathy, heart/body weight ratio (3.526 × 10^-3), serum creatine kinase (352.4±16.99 IU/L), lactate dehydrogenase (661.7±20.45 IU/L) levels were elevated in addition to altered lipid profile (TC - 118.4±4.25 mg/dL, TG - 263.3±9.99 mg/dL, VLDL - 52.66±1.99 mg/dL, LDL - 52.99±5.80 mg/dL and HDL - 12.78±0.36 mg/dL). The pre-cotreatment of candesartan and quercetin significantly restored the values to normal. The increased level of lipid peroxides (33.12±1.63 µmol/mg protein), serum troponin-T (1.82 ± 0.11 pg/mL) and nitric oxide (13.33±0.73 nmol/mg protein) level along with attenuating antioxidant profile, ie catalase, glutathione and superoxide dismutase (1.43±0.12 nmol/mg protein, 8.48±0.42 nmol/mg protein and 2.09±0.031 U/mg protein) were reversed to normal. Morphometry and histopathologic changes represented a beneficial effect of single and combination pre-cotreatment of drugs which significantly decreases adriamycin cardiac toxicity.

CONCLUSION

The overall result depicts more beneficial and cardioprotective effect of quercetin and candesartan combination as compared to their individual effects in doxorubicin treated animals. Therefore, this combination might be a suitable option to treat the cardiotoxic effect of doxorubicin.

A systematic review and meta-analysis of beta-blockers and renin-angiotensin system inhibitors for preventing left ventricular dysfunction due to anthracyclines or trastuzumab in patients with breast cancer

AIMS

Trastuzumab and anthracyclines, often used in the treatment of breast cancer, may impair myocardial function, and reduce left ventricular ejection fraction (LVEF), potentially causing heart failure. Randomized controlled trials (RCTs) have evaluated the effects of beta-blockers (BBs), angiotensin receptor blockers (ARBs), and angiotensin-converting enzyme inhibitors (ACEI) on trastuzumab- and anthracycline-associated cardiotoxicity. We report a meta-analysis of these RCTs in patients with breast cancer.

METHODS AND RESULTS

The primary analysis was on the effect of BBs and ACEI/ARBs on LVEF in patients treated with either trastuzumab or anthracyclines. A secondary analysis was done investigating the effect of BBs or ACEI/ARBs on LVEF in trastuzumab and anthracycline treatments. Only RCTs were included using the search term 'ARBs, ACEIs, BBs, anthracyclines, trastuzumab, and breast cancer' in PubMed, Embase, and CENTRAL up to 31 March 2021. A meta-analysis was conducted to estimate the mean difference (MD) in LVEF between intervention and placebo groups at follow-up. A total of nine RCTs (n = 1362) were included in the analysis. All patients were women. BBs and ACEI/ARBs were shown to attenuate the decline in LVEF during trastuzumab and anthracycline treatments [MD: 2.4; 95% confidence interval (CI): 0.3-4.2 and MD: 1.5; 95% CI: -0.6 to 3.7]. Compared with placebo, LVEF was significantly higher in patients assigned to BB or ACEI/ARB on trastuzumab (MD: 2.3; 95% CI: 0.0-4.6) but not on anthracyclines (MD: 1.9; 95% CI: -0.5 to 4.2).

CONCLUSION

Both BB and ACEI/ARB therapies were associated with the preservation of LVEF during trastuzumab and anthracycline-containing regimens as compared with placebo, suggesting both to be beneficial.

Long-term effectiveness of empiric cardio-protection in patients receiving cardiotoxic chemotherapies: A systematic review & bayesian network meta-analysis

BACKGROUND

Cardioprotective therapies represent an important avenue to reduce treatment-limiting cardiotoxicities in patients receiving chemotherapy. However, the optimal duration, strategy and long-term efficacy of empiric cardio-protection remains unknown.

METHODS

Leveraging the MEDLINE/Pubmed, CENTRAL and clinicaltrials.gov databases, we identified all randomised controlled trials investigating cardioprotective therapies from inception to November 2021 (PROSPERO-ID:CRD42021265006). Cardioprotective classes included ACEIs, ARBs, Beta-blockers, dexrazoxane (DEX), statins and mineralocorticoid receptor antagonists. The primary end-point was new-onset heart failure (HF). Secondary outcomes were the mean difference in left ventricular ejection fraction (LVEF) change, hypotension and all-cause mortality. Network meta-analyses were used to assess the cardioprotective effects of each therapy to deduce the most effective therapies. Both analyses were performed using a Bayesian random effects model to estimate risk ratios (RR) and 95% credible intervals (95% CrI).

RESULTS

Overall, from 726 articles, 39 trials evaluating 5931 participants (38.0 ± 19.1 years, 72.0% females) were identified. The use of any cardioprotective strategy associated with reduction in new-onset HF (RR:0.32; 95% CrI:0.19-0.55), improved LVEF (mean difference: 3.92%; 95% CrI:2.81-5.07), increased hypotension (RR:3.27; 95% CrI:1.38-9.87) and no difference in mortality. Based on control arms, the number-needed-to-treat for 'any' cardioprotective therapy to prevent one incident HF event was 45, including a number-needed-to-treat of 21 with ≥1 year of therapy. Dexrazoxane was most effective at HF prevention (Surface Under the Cumulative Ranking curve: 81.47%), and mineralocorticoid receptor antagonists were most effective at preserving LVEF (Surface Under the Cumulative Ranking curve: 99.22%).

CONCLUSION

Cardiotoxicity remains a challenge for patients requiring anticancer therapies. The initiation of extended duration cardioprotection reduces incident HF. Additional head-to-head trials are needed.

Therapeutic approaches targeting CD95L/CD95 signaling in cancer and autoimmune diseases

Cell death plays a pivotal role in the maintenance of tissue homeostasis. Key players in the controlled induction of cell death are the Death Receptors (DR). CD95 is a prototypic DR activated by its cognate ligand CD95L triggering programmed cell death. As a consequence, alterations in the CD95/CD95L pathway have been involved in several disease conditions ranging from autoimmune diseases to inflammation and cancer. CD95L-induced cell death has multiple roles in the immune response since it constitutes one of the mechanisms by which cytotoxic lymphocytes kill their targets, but it is also involved in the process of turning off the immune response. Furthermore, beyond the canonical pro-death signals, CD95L, which can be membrane-bound or soluble, also induces non-apoptotic signaling that contributes to its tumor-promoting and pro-inflammatory roles. The intent of this review is to describe the role of CD95/CD95L in the pathophysiology of cancers, autoimmune diseases and chronic inflammation and to discuss recently patented and emerging therapeutic strategies that exploit/block the CD95/CD95L system in these diseases.

Exploring the Pattern of Metabolic Alterations Causing Energy Imbalance via PPARα Dysregulation in Cardiac Muscle During Doxorubicin Treatment

Cardiotoxicity by anthracycline antineoplastic drug doxorubicin is one of the systemic toxicity of the cardiovascular system. The mechanism responsible for doxorubicin cardiotoxicity and lipid metabolism remains elusive. The current study tested the hypotheses that the role of peroxisome proliferator-activated receptor α (PPARα) in the progress of doxorubicin-induced cardiomyopathy and its mechanism behind lipid metabolism. In the present study, male rats were subjected to intraperitoneal injection (5-week period) of doxorubicin with different dosages such as low dosage (1.5 mg/kg body weight) and high dosage (15 mg/kg body weight) to induce doxorubicin cardiomyopathy. Myocardial PPARα was impaired in both low dosage and high dosage of doxorubicin-treated rats in a dose-dependent manner. The attenuated level of PPARα impairs the expression of the genes involved in mitochondrial transporter, fatty acid transportation, lipolysis, lipid metabolism, and fatty acid oxidation. Moreover, it disturbs the reverse triacylglycerol transporter apolipoprotein B-100 (APOB) in the myocardium. Doxorubicin elevates the circulatory lipid profile and glucose. Further aggravated lipid profile in circulation impedes the metabolism of lipid in cardiac tissue, which causes a lipotoxic condition in the heart and subsequently associated disease for the period of doxorubicin treatment. Elevated lipids in the circulation translocate into the heart dysregulates lipid metabolism in the heart, which causes augmented oxidative stress and necro-apoptosis and mediates lipotoxic conditions. This finding determines the mechanistic role of doxorubicin-disturbed lipid metabolism via PPARα, which leads to cardiac dysfunction.

Mitochondrial-Targeted Therapy for Doxorubicin-Induced Cardiotoxicity

Anthracyclines, such as doxorubicin, are effective chemotherapeutic agents for the treatment of cancer, but their clinical use is associated with severe and potentially life-threatening cardiotoxicity. Despite decades of research, treatment options remain limited. The mitochondria is commonly considered to be the main target of doxorubicin and mitochondrial dysfunction is the hallmark of doxorubicin-induced cardiotoxicity. Here, we review the pathogenic mechanisms of doxorubicin-induced cardiotoxicity and present an update on cardioprotective strategies for this disorder. Specifically, we focus on strategies that can protect the mitochondria and cover different therapeutic modalities encompassing small molecules, post-transcriptional regulators, and mitochondrial transfer. We also discuss the shortcomings of existing models of doxorubicin-induced cardiotoxicity and explore advances in the use of human pluripotent stem cell derived cardiomyocytes as a platform to facilitate the identification of novel treatments against this disorder.

Primary prevention of chronic anthracycline cardiotoxicity with ACE inhibitor is temporarily effective in rabbits, but benefits wane in post-treatment follow-up

Angiotensin-converting enzyme inhibitors (ACEis) have been used to treat anthracycline-induced cardiac dysfunction, and they appear beneficial for secondary prevention in high-risk patients. However, it remains unclear whether they truly prevent anthracycline-induced cardiac damage and provide long-lasting cardioprotection. This study aimed to examine the cardioprotective effects of perindopril on chronic anthracycline cardiotoxicity in a rabbit model previously validated with the cardioprotective agent dexrazoxane with focus on post-treatment follow-up (FU). Chronic cardiotoxicity was induced by daunorubicin (3 mg/kg/week for 10 weeks). Perindopril (0.05 mg/kg/day) was administered before and throughout chronic daunorubicin treatment. After the completion of treatment, significant benefits were observed in perindopril co-treated animals, particularly full prevention of daunorubicin-induced mortality and prevention or significant reductions in cardiac dysfunction, plasma cardiac troponin T levels, morphological damage, and most of the myocardial molecular alterations. However, these benefits significantly waned during 3 weeks of drug-free FU, which was not salvageable by administering a higher perindopril dose. In the longer (10-week) FU period, further worsening of left ventricular function and morphological damage occurred together with heart failure-related mortality. Continued perindopril treatment in the FU period did not reverse this trend but prevented heart failure-related mortality and reduced the severity of the progression of cardiac damage. These findings contrasted with the robust long-lasting protection observed previously for dexrazoxane in the same model. Hence, in this study, perindopril provided only temporary control of anthracycline cardiotoxicity development, which may be associated with the lack of effects on anthracycline-induced and topoisomerase II beta-dependent DNA damage responses in the heart.

Benazepril hydrochloride protects against doxorubicin cardiotoxicity by regulating the PI3K/Akt pathway

Doxorubicin (DOX) stimulates the generation of reactive oxygen species, thereby impairing mitochondrial functions. Angiotensin-converting enzyme inhibitors (ACEIs) have been identified to exhibit protective effects on cardiovascular diseases. The present study aimed to test the hypothesis that an ACEI benazepril hydrochloride (HCl) may protect against DOX-induced cardiotoxicity. The DOX injury model was established using rat embryonic cardiac myoblast cells (H9c2 cell line) treated with DOX in vitro. H9c2 cells were treated with benazepril-HCl, DOX or a mixture of DOX and benazepril-HCl to measure the activities of myocardial enzymes including lactate dehydrogenase (LDH), superoxide dismutase, catalase and glutathione peroxidase, in addition to the concentration of malondialdehyde in the culture medium. Cells without any treatment were used as a control. DOX treatment increased the levels of activity of myocardial enzymes in H9c2 cells compared with those in the untreated control cells. Additionally, co-treatment with benazepril-HCl significantly reduced the levels of apoptosis occurring due to DOX-mediated cellular damage. The mechanistic experiment revealed that pretreatment with benazepril-HCl counteracted the DOX-induced oxidative stress and suppressed the activation of apoptosis via the PI3K/Akt signaling pathway. By contrast, an Akt inhibitor (MK2206) inhibited the protective effects of benazepril-HCl against DOX-induced H9c2 cell injury, as revealed by increased LDH release in H9c2 cells. These results suggested that benazepril-HCl may potentially be administered as an adjuvant for DOX in long-term clinical use.

Analysis of Models of Doxorubicin-Induced Cardiomyopathy in Rats and Mice. A Modern View From the Perspective of the Pathophysiologist and the Clinician

Today the pharmacological possibilities of treating cancer are expanding and as a result, life expectancy is increasing against the background of chemotherapy and supportive treatment. In the conditions of successful antitumor treatment, complications associated with its toxic effect on healthy tissues and organs began to come to the fore. Anthracycline cardiomyopathy was the first serious cardiovascular complication to draw the attention of oncologists and cardiologists around the world. Anthracycline drugs such as doxorubicin, epirubicin, idarubicin are still widely used in oncological practice to treat a wide range of solid and hematological malignancies. Doxorubicin-induced cardiomyopathy is closely associated with an increase in oxidative stress, as evidenced by reactive oxygen species (ROS) nduced damage such as lipid peroxidation, and decreased levels of antioxidants. Myofibrillar destruction and dysregulation of intracellular calcium are also important mechanisms, usually associated with doxorubicin-induced cardiotoxicity. Despite the abundance of data on various mechanisms involved in the implementation of doxorubicin-induced cardiotoxicity, a final understanding of the mechanism of the development of doxorubicin cardiomyopathy has not yet been formed. It poses the most significant challenges to the development of new methods of prevention and treatment, as well as to the unambiguous choice of a specific treatment regimen using the existing pharmacological tools. In order to resolve these issues new models that could reflect the development of the chemotherapy drugs effects are needed. In this review we have summarized and analyzed information on the main existing models of doxorubicin cardiomyopathy using small laboratory animals. In addition, this paper discusses further areas of research devoted to the development and validation of new improved models of doxorubicin cardiomyopathy suitable both for studying the mechanisms of its implementation and for the preclinical drugs effectiveness assessment.

Irvingia gabonensis Seed Extract: An Effective Attenuator of Doxorubicin-Mediated Cardiotoxicity in Wistar Rats

Cardiotoxicity as an off-target effect of doxorubicin therapy is a major limiting factor for its clinical use as a choice cytotoxic agent. Seeds of Irvingia gabonensis have been reported to possess both nutritional and medicinal values which include antidiabetic, weight losing, antihyperlipidemic, and antioxidative effects. Protective effects of Irvingia gabonensis ethanol seed extract (IGESE) was investigated in doxorubicin (DOX)-mediated cardiotoxicity induced with single intraperitoneal injection of 15 mg/kg of DOX following the oral pretreatments of Wistar rats with 100-400 mg/kg/day of IGESE for 10 days, using serum cardiac enzyme markers (cardiac troponin I (cTI) and lactate dehydrogenase (LDH)), cardiac tissue oxidative stress markers (catalase (CAT), malonyldialdehyde (MDA), superoxide dismutase (SOD), glutathione-S-transferase (GST), glutathione peroxidase (GSH-Px), and reduced glutathione (GSH)), and cardiac histopathology endpoints. In addition, both qualitative and quantitative analyses to determine IGESE's secondary metabolites profile and its in vitro antioxidant activities were also conducted. Results revealed that serum cTnI and LDH were significantly elevated by the DOX treatment. Similarly, activities of tissue SOD, CAT, GST, and GSH levels were profoundly reduced, while GPx activity and MDA levels were profoundly increased by DOX treatment. These biochemical changes were associated with microthrombi formation in the DOX-treated cardiac tissues on histological examination. However, oral pretreatments with 100-400 mg/kg/day of IGESE dissolved in 5% DMSO in distilled water significantly attenuated increases in the serum cTnI and LDH, prevented significant alterations in the serum lipid profile and the tissue activities and levels of oxidative stress markers while improving cardiovascular disease risk indices and DOX-induced histopathological lesions. The in vitro antioxidant studies showed IGESE to have good antioxidant profile and contained 56 major secondary metabolites prominent among which are γ-sitosterol, Phytol, neophytadiene, stigmasterol, vitamin E, hexadecanoic acid and its ethyl ester, Phytyl palmitate, campesterol, lupeol, and squalene. Overall, both the in vitro and in vivo findings indicate that IGESE may be a promising prophylactic cardioprotective agent against DOX-induced cardiotoxicity, at least in part mediated via IGESE's antioxidant and free radical scavenging and antithrombotic mechanisms.

Anthracycline-induced cardiotoxicity and renin-angiotensin-aldosterone system-from molecular mechanisms to therapeutic applications

Few millions of new cancer cases are diagnosed worldwide every year. Due to significant progress in understanding cancer biology and developing new therapies, the mortality rates are decreasing with many of patients that can be completely cured. However, vast majority of them require chemotherapy which comes with high medical costs in terms of adverse events, of which cardiotoxicity is one of the most serious and challenging. Anthracyclines (doxorubicin, epirubicin) are a class of cytotoxic agents used in treatment of breast cancer, sarcomas, or hematological malignancies that are associated with high risk of cardiotoxicity that is observed in even up to 30% of patients and can be diagnosed years after the therapy. The mechanism, in which anthracyclines cause cardiotoxicity are not well known, but it is proposed that dysregulation of renin-angiotensin-aldosterone system (RAAS), one of main humoral regulators of cardiovascular system, may play a significant role. There is increasing evidence that drugs targeting this system can be effective in the prevention and treatment of anthracycline-induced cardiotoxicity what has recently found reflection in the recommendation of some scientific societies. In this review, we comprehensively describe possible mechanisms how anthracyclines affect RAAS and lead to cardiotoxicity. Moreover, we critically review available preclinical and clinical data on use of RAAS inhibitors in the primary and secondary prevention and treatment of cardiac adverse events associated with anthracycline-based chemotherapy.

Anthracycline-induced cardiotoxicity in the chemotherapy treatment of breast cancer: Preventive strategies and treatment

Anthracyclines are highly effective chemotherapeutic agents, used for a wide variety of malignancies. Cardiotoxicity is a well-recognized side effect of anthracycline therapy that limits the total amount of drug administered and can cause heart failure in some patients. Most experimental data support oxidative stress as the etiology of anthracycline-induced cardiotoxicity. The objective of this paper was to provide a review of the clinical classification, risk factors, monitoring and prevention of anthracycline-induced cardiotoxicity in patients with breast cancer.

Doxorubicin-Induced Cardiomyopathy in Children

Doxorubicin-induced cardiotoxicity in childhood cancer survivors is a growing problem. The population of patients at risk for cardiovascular disease is steadily increasing, as five-year survival rates for all types of childhood cancers continue to improve. Doxorubicin affects the developing heart differently from the adult heart and in a subset of exposed patients, childhood exposure leads to late, irreversible cardiomyopathy. Notably, the prevalence of late-onset toxicity is increasing in parallel with improved survival. By the year 2020, it is estimated that there will be 500,000 childhood cancer survivors and over 50,000 of them will suffer from doxorubicin-induced cardiotoxicity. The majority of the research to-date, concentrated on childhood cancer survivors, has focused mostly on clinical outcomes through well-designed epidemiological and retrospective cohort studies. Preclinical studies have elucidated many of the cellular mechanisms that elicit acute toxicity in cardiomyocytes. However, more research is needed in the areas of early- and late-onset cardiotoxicity and more importantly improving the scientific understanding of how other cells present in the cardiac milieu are impacted by doxorubicin exposure. The overall goal of this review is to succinctly summarize the major clinical and preclinical studies focused on doxorubicin-induced cardiotoxicity. As the prevalence of patients affected by doxorubicin exposure continues to increase, it is imperative that the major gaps in existing research are identified and subsequently utilized to develop appropriate research priorities for the coming years. Well-designed preclinical research models will enhance our understanding of the pathophysiology of doxorubicin-induced cardiotoxicity and directly lead to better diagnosis, treatment, and prevention. © 2019 American Physiological Society. Compr Physiol 9:905-931, 2019.

Protecting the heart in cancer therapy

Recent advances in cancer prevention and management have led to an exponential increase of cancer survivors worldwide. Regrettably, cardiovascular disease has risen in the aftermath as one of the most devastating consequences of cancer therapies. In this work, we define cancer therapeutics-induced cardiotoxicity as the direct or indirect cardiovascular injury or injurious effect caused by cancer therapies. We describe four progressive stages of this condition and four corresponding levels of prevention, each having a specific goal, focus, and means of action. We subsequently unfold this didactic framework, surveying mechanisms of cardiotoxicity, risk factors, cardioprotectants, biomarkers, and diagnostic imaging modalities. Finally, we outline the most current evidence-based recommendations in this area according to multidisciplinary expert consensus guidelines.

Renin-Angiotensin System Inhibitors to Mitigate Cancer Treatment-Related Adverse Events

Treatment-related side effects are a major clinical problem in cancer treatment. They lead to reduced compliance to therapy as well as increased morbidity and mortality. Well-known are the sequelae of chemotherapy on the heart, especially in childhood cancer survivors. Therefore, measures to mitigate the adverse events of cancer therapy may improve health and quality of life in patients with cancer, both in the short and long term. The renin-angiotensin system (RAS) affects all hallmarks of cancer, and blockage of the RAS is associated with an improved outcome in several cancer types. There is also increasing evidence that inhibition of the RAS might be able to alleviate or even prevent certain types of cancer treatment-related adverse effects. In this review, we summarize the potential of RAS inhibitors to mitigate cancer treatment-related adverse events, with a special emphasis on chemotherapy-induced cardiotoxicity, radiation injury, and arterial hypertension. Clin Cancer Res; 24(16); 3803-12. ©2018 AACR.

Anthracycline-induced cardiotoxicity: A multicenter randomised trial comparing two strategies for guiding prevention with enalapril: The International CardioOncology Society-one trial

BACKGROUND

Troponin changes over time have been suggested to allow for an early diagnosis of cardiac injury ensuing cancer chemotherapy; cancer patients with troponin elevation may benefit of therapy with enalapril. It is unknown whether a preventive treatment with enalapril may further increase the benefit.

METHODS

The International CardioOncology Society-one trial (ICOS-ONE) was a controlled, open-label trial conducted in 21 Italian hospitals. Patients were randomly assigned to two strategies: enalapril in all patients started before chemotherapy (CT; 'prevention' arm), and enalapril started only in patients with an increase in troponin during or after CT ('troponin-triggered' arm). Troponin was assayed locally in 2596 blood samples, before and after each anthracycline-containing CT cycle and at each study visit; electrocardiogram and echocardiogram were done at baseline, and at 1, 3, 6 and 12-month follow-up. Primary outcome was the incidence of troponin elevation above the threshold.

FINDINGS

Of the 273 patients, 88% were women, mean age 51 ± 12 years. The majority (76%) had breast cancer, 3% had a history of hypertension and 4% were diabetic. Epirubicin and doxorubicin were most commonly prescribed, with median cumulative doses of 360 [270-360] and 240 [240-240] mg/m², respectively. The incidence of troponin elevation was 23% in the prevention and 26% in the troponin-triggered group (p = 0.50). Three patients (1.1%) -two in the prevention, one in the troponin-triggered group-developed cardiotoxicity, defined as 10% point reduction of LV ejection fraction, with values lower than 50%.

INTERPRETATION

Low cumulative doses of anthracyclines in adult patients with low cardiovascular risk can raise troponins, without differences between the two strategies of giving enalapril. Considering a benefit of enalapril in the prevention of LV dysfunction, a troponin-triggered strategy may be more convenient.

Breakthroughs in modern cancer therapy and elusive cardiotoxicity: Critical research-practice gaps, challenges, and insights

To date, five cancer treatment modalities have been defined. The three traditional modalities of cancer treatment are surgery, radiotherapy, and conventional chemotherapy, and the two modern modalities include molecularly targeted therapy (the fourth modality) and immunotherapy (the fifth modality). The cardiotoxicity associated with conventional chemotherapy and radiotherapy is well known. Similar adverse cardiac events are resurging with the fourth modality. Aside from the conventional and newer targeted agents, even the most newly developed, immune-based therapeutic modalities of anticancer treatment (the fifth modality), e.g., immune checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy, have unfortunately led to potentially lethal cardiotoxicity in patients. Cardiac complications represent unresolved and potentially life-threatening conditions in cancer survivors, while effective clinical management remains quite challenging. As a consequence, morbidity and mortality related to cardiac complications now threaten to offset some favorable benefits of modern cancer treatments in cancer-related survival, regardless of the oncologic prognosis. This review focuses on identifying critical research-practice gaps, addressing real-world challenges and pinpointing real-time insights in general terms under the context of clinical cardiotoxicity induced by the fourth and fifth modalities of cancer treatment. The information ranges from basic science to clinical management in the field of cardio-oncology and crosses the interface between oncology and onco-pharmacology. The complexity of the ongoing clinical problem is addressed at different levels. A better understanding of these research-practice gaps may advance research initiatives on the development of mechanism-based diagnoses and treatments for the effective clinical management of cardiotoxicity.

Effect of Enalapril on Preventing Anthracycline-Induced Cardiomyopathy

Anthracycline (ANT) is a topoisomerase-interacting agent that is used in most malignancy treatments. We investigated the efficacy of enalapril (angiotensin-converting enzyme inhibitor) in the prevention of ANT-induced cardiomyopathy. In this randomized, single-blind, and placebo-controlled study, 69 patients with a newly diagnosed malignancy for which ANT therapy was planned were randomly assigned to either a group receiving enalapril (n = 34) or placebo (n = 35). Echocardiography studies were performed before chemotherapy and at 6 months after randomization. Additionally, troponin I and creatinine kinase-MB (CK-MB) were measured 1 month after the initiation of chemotherapy. In the enalapril group, the mean left ventricular ejection fraction (LVEF) (p = 0.58) was the same at baseline and 6 months after randomization. Conversely, LVEF significantly decreased in the control group (p < 0.001). Additionally, LV end systolic volume and left atrial diameter were significantly increased compared with the baseline measures in the control group. According to the tissue Doppler study, the mitral annuli early diastolic (e') and peak systolic (s') velocities were significantly reduced, and the E (the peak early diastolic velocity)/e' ratio was significantly increased in the control group. Furthermore, the TnI and CK-MB levels were significantly higher in the control group than in the enalapril group. Enalapril appears efficacious in preserving systolic and diastolic function in cancer patients treated with ANTs.

Mitochondrial ROS-induced ERK1/2 activation and HSF2-mediated AT1 R upregulation are required for doxorubicin-induced cardiotoxicity

Doxorubicin (DOX), one useful chemotherapeutic agent, is limited in clinical use because of its serious cardiotoxicity. Growing evidence suggests that angiotensin receptor blockers (ARBs) have cardioprotective effects in DOX-induced cardiomyopathy. However, the detailed mechanisms underlying the action of ARBs on the prevention of DOX-induced cardiomyocyte cell death have yet to be investigated. Our results showed that angiotensin II receptor type I (AT₁ R) plays a critical role in DOX-induced cardiomyocyte apoptosis. We found that MAPK signaling pathways, especially ERK1/2, participated in modulating AT₁ R gene expression through DOX-induced mitochondrial ROS release. These results showed that several potential heat shock binding elements (HSE), which can be recognized by heat shock factors (HSFs), located at the AT₁ R promoter region. HSF2 markedly translocated from the cytoplasm to the nucleus when cardiomyocytes were damaged by DOX. Furthermore, the DNA binding activity of HSF2 was enhanced by DOX via deSUMOylation. Overexpression of HSF2 enhanced DOX-induced cardiomyocyte cell death as well. Taken together, we found that DOX induced mitochondrial ROS release to activate ERK-mediated HSF2 nuclear translocation and AT₁ R upregulation causing DOX-damaged heart failure in vitro and in vivo.

Cardiac safety of systemic therapy in breast cancer patients with high risk of atherosclerosis complications

Aim: This study was designed to verify the efficacy of breast cancer treatment and its cardiac toxicity in population with significant cardiac comorbidities. Materials & methods: Prospective observational study was conducted in 48 patients. Results: The increase and dependence of echocardiographic parameter early/late were observed on hemoglobin level in all patients, and white blood cells and cholesterol in patients with diabetic were reported. Patients undergo left ventricle diameter change on treatment. Conclusion: Use of potentially cardiotoxic chemo regimens in breast cancer patients with cardiac comorbidities, with optimized cardiac therapy accordingly can save patients from development of early myocardial dysfunction induced by chemotherapy – limiting factor to minimize the risk is optimization of lipid level, red blood cell count and platelets count.

Cardioprotective Effect of Grape Seed Extract on Chronic Doxorubicin-Induced Cardiac Toxicity in Wistar Rats

Purpose: The aim of the present study was to determine the ability of grape seed extract (GSE) as a powerful antioxidant in preventing adverse effect of doxorubicin (DOX) on heart function. Methods: Male rats were divided into three groups: control, DOX (2 mg/kg/48h, for 12 days) and GSE (100 mg/kg/24h, for 16 days) plus DOX. Left ventricular (LV) function and hemodynamic parameters were assessed using echocardiography, electrocardiography and a Millar pressure catheter. Histopathological analysis and in vitro antitumor activity were also evaluated. Results: DOX induced heart damage in rats through decreasing the left ventricular systolic and diastolic pressures, rate of rise/decrease of LV pressure, ejection fraction, fractional shortening and contractility index as demonstrated by echocardiography, electrocardiography and hemodynamic parameters relative to control group. Our data demonstrated that GSE treatment markedly attenuated DOX-induced toxicity, structural changes in myocardium and improved ventricular function. Additionally, GSE did not intervene with the antitumor effect of DOX. Conclusion: Collectively, the results suggest that GSE is potentially protective against DOX-induced toxicity in rat heart and maybe increase therapeutic index of DOX in human cancer treatment.

Antioxidant and Cardioprotective Properties of the Sulphydryl Angiotensinconverting Enzyme Inhibitor Zofenopril

Zofenopril, a new potent sulphydryl angiotensin-converting enzyme (ACE) inhibitor, is characterized by high lipophilicity, selective cardiac ACE inhibition, and antioxidant and tissue protective activities. In vitro and in vivo experiments suggest that zofenopril exerts antioxidant properties at clinically achievable tissue concentrations. In endothelial cells, zofenopril enhances nitric oxide production, attenuates atherosclerotic lesion development and inhibits adhesion molecule expression by reducing reactive oxygen species. These peculiar characteristics are reflected in the drug's cardioprotective activity, which has been shown to be greater than that of non-sulphydryl ACE inhibitors. Cardiac hypertrophy was also reduced by chronic zofenopril administration, independently of its blood pressure-reducing effect. ACE inhibitors with a sulphydryl group could have an advantage in improving vascular function and reducing cardiac impairment compared with non-sulphydryl-containing ACE inhibitors. This could explain zofenopril's remarkable clinical efficacy post-infarction, and potentially beneficial use in prevention and therapy of cardiovascular diseases, such as atherosclerosis, thrombosis and heart failure.

Targeting endothelial cell metabolism for cardio-protection from the toxicity of antitumor agents

The vascular endothelium plays a fundamental role in the maintenance of tissue homeostasis, regulating local blood flow and other physiological processes. Chemotherapeutic drugs and target therapies, including antiangiogenic drugs targeting vascular endothelial growth factor (VEGF) or its receptors, not only efficiently act against tumor growth, but may also induce endothelial dysfunction and cardiovascular toxicity. Continued research efforts aim to better understand, prevent and mitigate these chemotherapy associated cardiovascular diseases. Conventional chemotherapeutic agents, such as anthracyclines, platinum compounds, and taxanes, and newer targeted agents, such as bevacizumab, trastuzumab, and tyrosine kinase inhibitors, have known risk of cardiovascular toxicity, which can limit their effectiveness by promoting increased morbidity and/or mortality. This review describes a) the activity of anticancer agents in inducing endothelial dysfunction, b) the metabolic pathways and signalling cascades which may be targeted by protective agents able to maintain or restore endothelial cell function, such as endothelial nitric oxide synthase/fibroblast growth factor-2 (eNOS-FGF-2) pathway, and c) the drugs/strategies reported to improve endothelial function and to reduce the risks of cardiovascular diseases such as angiotensin converting enzyme inhibitors (ACEi) and beta blockers, that are fundamental therapies in chronic heart failure (HF), as well as non-standard HF treatments such ad nitric oxide donors and antioxidant strategies. There is increasing interest in whether ACEi, beta-blockers, and/or statins might prevent and/or therapeutically control cardiotoxic effects in cancer patients. Maintaining endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor drug-effectiveness, is essential for preserving or recovering cardiovascular homeostasis. In this respect, the early detection and immediate therapy of cardiovascular toxicity appear crucial for substantial recovery of cardiac function in cancer patients.

Fixed dose combination therapy loperamide and niacin ameliorates diethylnitrosamine-induced liver carcinogenesis in albino Wistar rats

Hepatocellular carcinoma (HCC) is among the most lethal cancers (five-year survival rates under 11%), which makes it the third most frequent cause of cancer related deaths in men and sixth in women.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

Use of the ACE inhibitor zofenopril in the treatment of ischemic heart disease

Zofenopril, an inhibitor of the angiotensin-converting enzyme (ACE), has recently been widely introduced into the pharmaceutical market. Its clinical safety and efficacy has been demonstrated in patients with hypertension and in patients with acute myocardial infarction (AMI). The Survival of Myocardial Infarction Long-term Evaluation (SMILE) project provided valuable information regarding the safety of early onset ACE inhibition with zofenopril after AMI and a greater perception of the early and late benefits. The SMILE-I study demonstrated that most benefits of ACE inhibition may be obtained early after AMI and persist after discontinuation of treatment. The SMILE-II study demonstrated that early zofenopril treatment (initiated <12 h) is safe and associated with a low rate of severe hypotension in thrombolyzed patients with acute myocardial infarction when administered in accordance with an adequate dose-titration scheme. Many other studies of clinical ACE-inhibitors (ACEIs) over the last 30 years have provided us with information in order to understand the effects of ACEIs and have demonstrated that patients benefit from ACEI treatment at different stages of the pathophysiological continuum of cardiovascular diseases. The current guidelines recommend that ACEIs should be used for routine secondary prevention in all patients with coronary artery disease and should be considered for all other patients with coronary or other vascular disease unless contraindicated.

Protective effect of a direct renin inhibitor in acute murine model of cardiotoxicity and nephrotoxicity

This study aimed to investigate the possible protective effects of aliskiren against doxorubicin (DXR)-induced cardiorenal injury and to identify the mechanisms involved. Intraperitoneal administration of DXR (15 mg/kg, body weight, as a single dose) caused significant induction in the levels of angiotensin I, caspase-3, lactate dehydrogenase (LDH), lipid peroxidation malondialdehyde (MDA), urea, and creatinine. Concomitant decline in the levels of albumin and total protein in plasma, reduction in reduced glutathione (GSH), and antiperoxidative enzyme superoxide dismutase (SOD) levels followed by ultrastructural alterations in the myocardial and renal tissues were also observed. Oral administration of aliskiren (100 mg/kg, for a period of 14 days) significantly prevented all these DXR-induced adverse effects and maintained the rats near to normal status. However, telmisartan (10 mg/kg) pretreatment has shown slight protection in DXR-induced renal injury as evidenced by broadening of podocyte foot process and narrowing of slit pore diameter. The results of aliskiren were compared with telmisartan which was used as reference in this study. These results suggested that aliskiren has protective effects against acute model of DXR-induced cardiotoxicity and nephrotoxicity, implying that plasma renin activity plays a role in DXR-induced cardio-renal injury.

The sulphydryl containing ACE inhibitor Zofenoprilat protects coronary endothelium from Doxorubicin-induced apoptosis

Pediatric and adult cancer patients, following the use of the antitumor drug Doxorubicin develop cardiotoxicity. Pharmacological protection of microvascular endothelium might produce a double benefit: (i) reduction of myocardial toxicity (the primary target of Doxorubicin action) and (ii) maintenance of the vascular functionality for the adequate delivery of chemotherapeutics to tumor cells. This study was aimed to evaluate the mechanisms responsible of the protective effects of the angiotensin converting enzyme inhibitor (ACEI) Zofenoprilat against the toxic effects exerted by Doxorubicin on coronary microvascular endothelium. We found that exposure of endothelial cells to Doxorubicin (0.1-1μM range) impaired cell survival by promoting their apoptosis. ERK1/2 related p53 activation, but not reactive oxygen species, was responsible for Doxorubicin induced caspase-3 cleavage. P53 mediated-apoptosis and impairment of survival were reverted by treatment with Zofenoprilat. The previously described PI-3K/eNOS/endogenous fibroblast growth factor signaling was not involved in the protective effect, which, instead, could be ascribed to cystathionine gamma lyase dependent availability of H2S from Zofenoprilat. Furthermore, considering the tumor environment, the treatment of endothelial/tumor co-cultures with Zofenoprilat did not affect the antitumor efficacy of Doxorubicin. In conclusion the ACEI Zofenoprilat exerts a protective effect on Doxorubicin induced endothelial damage, without affecting its antitumor efficacy. Thus, sulfhydryl containing ACEI may be a useful therapy for Doxorubicin-induced cardiotoxicity.

Enalaprilat increases PPARβ/δ expression, without influence on PPARα and PPARγ, and modulate cardiac function in sub-acute model of daunorubicin-induced cardiomyopathy

Anthracycline therapy is limited by a cardiotoxicity that may eventually lead to chronic heart failure which is thought to be prevented by ACE inhibitors (ACEi). However, the protective effect of ACEi in early stages of this specific injury remains elusive. Activated nuclear transcription factors peroxisome proliferator-activated receptors (PPAR) regulate cellular metabolism, but their involvement in anthracycline cardiomyopathy has not been investigated yet. For this purpose, Wistar rats were administered with daunorubicin (i.p., 3 mg/kg, in 48 h intervals) or co-administered with daunorubicine and enalaprilat (i.p., 5 mg/kg in 12 h intervals). Control animals received vehicle. Left ventricular function was measured invasively under anesthesia. Cell-shortening was measured by videomicroscopy in isolated cardiomyocytes. Expression of PPARs mRNA in cardiac tissue was measured by Real-Time PCR. Although the hemodynamic parameters of daunorubicin-treated rats remained altered upon ACEi co-administration, ACEi normalized daunorubicin-induced QT prolongation. On cellular level, ACEi normalized altered basal and isoproterenol-stimulated cardiac cell shortening in daunorubicine-treated group. Moreover, anthracycline administration significantly up-regulated heart PPARα mRNA and its expression remained increased after ACEi co-administration. On the other hand, the expression of cardiac PPARβ/δ was not altered in anthracycline-treated animals, whereas co-administration of ACEi increased its expression. Conclusively, effect of ACEi can be already detected in sub-acute phase of anthracycline-induced cardiotoxicity. Altered expression of heart PPARs may suggest these nuclear receptors as a novel target in anthracycline cardiomyopathy.

Enalapril and carvedilol for preventing chemotherapy-induced left ventricular systolic dysfunction in patients with malignant hemopathies: the OVERCOME trial (preventiOn of left Ventricular dysfunction with Enalapril and caRvedilol in patients submitted to intensive ChemOtherapy for the treatment of Malignant hEmopathies)

OBJECTIVES

This study sought to evaluate the efficacy of enalapril and carvedilol to prevent chemotherapy-induced left ventricular systolic dysfunction (LVSD) in patients with hematological malignancies.

BACKGROUND

Current chemotherapy may induce LVSD. Angiotensin-converting enzyme inhibitors and beta-blockers prevent LVSD in animal models of anthracycline-induced cardiomyopathy.

METHODS

In this randomized, controlled study, 90 patients with recently diagnosed acute leukemia (n = 36) or patients with malignant hemopathies undergoing autologous hematopoietic stem cell transplantation (HSCT) (n = 54) and without LVSD were randomly assigned to a group receiving enalapril and carvedilol (n = 45) or to a control group (n = 45). Echocardiographic and cardiac magnetic resonance (CMR) imaging studies were performed before and at 6 months after randomization. The primary efficacy endpoint was the absolute change from baseline in LV ejection fraction (LVEF).

RESULTS

The mean age of patients was 50 ± 13 years old, and 43% were women. At 6 months, LVEF did not change in the intervention group but significantly decreased in controls, resulting in a -3.1% absolute difference by echocardiography (p = 0.035) and -3.4% (p = 0.09) in the 59 patients who underwent CMR. The corresponding absolute difference (95% confidence interval [CI]) in LVEF was -6.38% (95% CI: -11.9 to -0.9) in patients with acute leukemia and -1.0% (95% CI: -4.5 to 2.5) in patients undergoing autologous HSCT (p = 0.08 for interaction between treatment effect and disease category). Compared to controls, patients in the intervention group had a lower incidence of the combined event of death or heart failure (6.7% vs. 22%, p = 0.036) and of death, heart failure, or a final LVEF <45% (6.7% vs. 24.4%, p = 0.02).

CONCLUSIONS

Combined treatment with enalapril and carvedilol may prevent LVSD in patients with malignant hemopathies treated with intensive chemotherapy. The clinical relevance of this strategy should be confirmed in larger studies. (Prevention of Left Ventricular Dysfunction During Chemotherapy [OVERCOME]; NCT01110824).

POTENTIAL OF THE MODERN ACE INHIBITOR ZOFENOPRIL IN CLINICAL PRACTICE: CARDIOPROTECTIVE, ANTI-ISCHEMIC, AND ANTIATHEROGENIC EFFECTS

The review discusses various aspects of angiotensin-converting enzyme (ACE) inhibitor therapy in patients with cardiovascular disease (CVD), including acute myocardial infarction (AMI). The focus is on the modern ACE inhibitor zofenopril, its specific pharmacological characteristics, and additional cardioprotective, anti-ischemic, and antiatherogenic effects. The existing evidence of clinical effectiveness of zofenopril and its potential for a wider use in clinical practice are also addressed. 

Chemotherapy-induced cardiotoxicity

Anthracycline-based chemotherapeutics have long been recognized as effective agents for treating a wide range of malignancies. However, their use is not without significant adverse cardiotoxic side effects. Strategies for prevention involve limiting free-radical production and subsequent cardiac myocyte damage. Dexrazoxane remains the most widely studied cardioprotective medication. Alternative agents may reduce cardiotoxicity but may still cause significant cardiovascular problems. The role of β-blockers and angiotensin-converting enzyme inhibitors in the treatment of heart failure is well proven. The role of these medications in the prevention and treatment of chemotherapy-induced cardiotoxicity is not well established.

Mitochondrionopathy phenotype in doxorubicin-treated Wistar rats depends on treatment protocol and is cardiac-specific

Although doxorubicin (DOX) is a very effective antineoplastic agent, its clinical use is limited by a dose-dependent, persistent and cumulative cardiotoxicity, whose mechanism remains to be elucidated. Previous works in animal models have failed to use a multi-organ approach to demonstrate that DOX-associated toxicity is selective to the cardiac tissue. In this context, the present work aims to investigate in vivo DOX cardiac, hepatic and renal toxicity in the same animal model, with special relevance on alterations of mitochondrial bioenergetics. To this end, male Wistar rats were sub-chronically (7 wks, 2 mg/Kg) or acutely (20 mg/Kg) treated with DOX and sacrificed one week or 24 hours after the last injection, respectively. Alterations of mitochondrial bioenergetics showed treatment-dependent differences between tissues. No alterations were observed for cardiac mitochondria in the acute model but decreased ADP-stimulated respiration was detected in the sub-chronic treatment. In the acute treatment model, ADP-stimulated respiration was increased in liver and decreased in kidney mitochondria. Aconitase activity, a marker of oxidative stress, was decreased in renal mitochondria in the acute and in heart in the sub-chronic model. Interestingly, alterations of cardiac mitochondrial bioenergetics co-existed with an absence of echocardiograph, histopathological or ultra-structural alterations. Besides, no plasma markers of cardiac injury were found in any of the time points studied. The results confirm that alterations of mitochondrial function, which are more evident in the heart, are an early marker of DOX-induced toxicity, existing even in the absence of cardiac functional alterations.

Management of chemotherapy induced cardiomyopathy

Chemotherapy related cardiac dysfunction (CRCD) is a serious complication of anticancer therapy. CRCD can be classified into two types. Type I CRCD is exemplified by anthracyline- induced cardiac dysfunction and type II CRCD is exemplified by trastuzumab- induced cardiac dysfunction. The mechanism of cardiac toxicity in both types is not well defined. Certain risk factors may play a role in developing the cardiac injury, most importantly, the cumulative dose when dealing with anthracycline induced cardiotoxicity. Establishing an early diagnosis and initiating early treatment may be an important step in preventing irreversible cardiac injury especially in type I CRCD. Currently there are no guidelines developed specifically for the treatment of chemotherapy induced cardiomyopathy (CIC), however a few small studies support the use of neurohormonal antagonists in the treatment and prevention of CIC. Large multi- centers trials are needed to establish guidelines for CIC. Until then, we advocate following the American College of Cardiology/ American Heart Association (ACC/AHA) and Heart Failure Society of America (HFSA) guidelines. Additionally, a close collaboration between the patient's cardiologist and oncologist is strongly recommended in order to establish a long term plan for the patient.

The protective effects of silymarin against doxorubicin-induced cardiotoxicity and hepatotoxicity in rats

Silymarin is a complex of five major compounds, and silibinin is the most biologically active component of the complex. The aim of this study was to investigate, evaluate and confirm the potential cardioprotective and hepatoprotective effects of administration of silymarin, rich in silibinin, at a dose of 60 mg/kg orally for a time-span of 12 days on doxorubicin induced toxicity in male Wistar rats. The in vivo model was used to explore whether silymarin could prevent damage of liver and heart tissue induced by doxorubicin administered every other day at dose of 1.66 mg/kg intraperitoneally for twelve days. In the study the change of body weight, ECG changes, biochemical parameters of oxidative stress, serum activity of alanine and aspartate transaminase, lactate dehydrogenase, creatine kinase and histological preparations of heart and liver samples of treated animals were examined. According to physiological, pharmacological, microscopic and biochemical results, we confirmed that at the examined dose, silymarin exhibits a protective influence on the heart and liver tissue against toxicity induced by doxorubicin.

Pretreatment with angiotensin-converting enzyme inhibitor improves doxorubicin-induced cardiomyopathy via preservation of mitochondrial function

OBJECTIVE

Doxorubicin is a widely used chemotherapy drug, but its application is associated with cardiotoxicity. Free radical generation and mitochondrial dysfunction are thought to contribute to doxorubicin-induced cardiac failure. Angiotensin-converting enzyme inhibitors are commonly used as cardioprotective agents and have recently been shown in clinical studies to be efficacious in the prevention of anthracycline-induced heart failure. This study evaluated a mechanism for these protective effects by testing the ability of the angiotensin-converting enzyme inhibitor enalapril to preserve mitochondrial function in a model of chronic doxorubicin treatment in rats.

METHODS

Sprague Dawley rats were divided into 3 groups and followed for a total of 10 weeks: (1) control-untreated, (2) doxorubicin treated, and (3) doxorubicin + enalapril treated. Doxorubicin was administered via intraperitoneal injection at weekly intervals from weeks 2 to 7. Enalapril was administered in the drinking water of the doxorubicin + enalapril group for the study duration.

RESULTS

Doxorubicin treatment produced a significant loss in left ventricular contractility (P < .05), decrease in mitochondrial function via impairment of state-3 respiration, decrease in the cytosolic fraction of adenosine triphosphate, and up-regulation of free radical production. Enalapril significantly attenuated the decrease in percent fractional shortening (P < .05) and prevented the doxorubicin-associated reduction in respiratory efficiency and cytosolic adenosine triphosphate content (P < .05). Enalapril also abolished the robust doxorubicin-induced increase in free radical formation.

CONCLUSIONS

Administration of enalapril attenuates doxorubicin-induced cardiac dysfunction via preservation of mitochondrial respiratory efficiency and reduction in doxorubicin-associated free radical generation.

Prevention and treatment of cardiomyopathy and heart failure in patients receiving cancer chemotherapy

Chemotherapy (CT)-induced cardiotoxicity remains an unresolved problem that strongly affects the quality of life and overall survival of cancer patients. The most typical form of cardiotoxicity, a dilated cardiomyopathy (CMP), usually becomes manifest late in the course of the disease and is classically considered to be refractory to therapy. Preventing cardiotoxicity remains the most important strategy, and several measures have been proposed, including cardiac function monitoring, limitation of CT dose, use of anthracycline analogues and cardioprotectants, and early detection of cardiotoxicity by biomarkers. The response to modern heart failure therapy of CT-induced CMP has never been evaluated in clinical trials, and no definite guidelines have been adopted. Although it is likely that medications used for other forms of CMP, particularly angiotensin-converting enzyme inhibitors and beta-blockers, may be highly effective, there is still some unjustified concern regarding their use in cancer patients.