Cardioprotective effect of dexrazoxane during treatment with doxorubicin: a study using low-dose dobutamine stress echocardiography

Cardioprotective Strategies from Cardiotoxicity in Cancer Patients: A Comprehensive Review

Cardiotoxicity is a significant complication of chemotherapeutic agents in cancer patients. Cardiovascular incidents including LV dysfunction, heart failure (HF), severe arrhythmias, arterial hypertension, and death are associated with high morbidity and mortality. Risk stratification of cancer patients prior to initiation of chemotherapy is crucial, especially in high-risk patients for cardiotoxicity. The early identification and management of potential risk factors for cardiovascular side effects seems to contribute to the prevention or minimization of cardiotoxicity. Screening of cancer patients includes biomarkers such as cTnI and natriuretic peptide and imaging measurements such as LV function, global longitudinal strain, and cardiac MRI. Cardioprotective strategies have been investigated over the last two decades. These strategies for either primary or secondary prevention include medical therapy such as ACE inhibitors, ARBs, b-blockers, aldosterone antagonists, statins and dexrazoxane, physical therapy, and reduction of chemotherapeutic dosages. However, data regarding dosages, duration of medical therapy, and potential interactions with chemotherapeutic agents are still limited. Collaboration among oncologists, cardiologists, and cardio-oncologists could establish management cardioprotective strategies and approved follow-up protocols in patients with cancer receiving chemotherapy.

Strategies to prevent anthracycline-induced cardiotoxicity in cancer survivors

Cancer diagnostics and therapies have improved steadily over the last few decades, markedly increasing life expectancy for patients at all ages. However, conventional and newer anti-neoplastic therapies can cause short- and long-term cardiotoxicity. The clinical implications of this cardiotoxicity become more important with the increasing use of cardiotoxic drugs. The implications are especially serious among patients predisposed to adverse cardiac effects, such as youth, the elderly, those with cardiovascular comorbidities, and those receiving additional chemotherapies or thoracic radiation. However, the optimal strategy for preventing and managing chemotherapy-induced cardiotoxicity remains unknown. The routine use of neurohormonal antagonists for cardioprotection is not currently justified, given the marginal benefits and associated adverse events, particularly with long-term use. The only United States Food and Drug Administration and European Medicines Agency approved treatment for preventing anthracycline-related cardiomyopathy is dexrazoxane. We advocate administering dexrazoxane during cancer treatment to limit the cardiotoxic effects of anthracycline chemotherapy.

Anthracycline-associated cardiotoxicity in adults: systematic review on the cardioprotective role of beta-blockers

OBJECTIVES

This study aimed at assessing the role of beta-blockers on preventing anthracycline-induced cardiotoxicity in adults.

METHODS

A systematic review was performed on electronic databases, including relevant studies that analysed beta-blockers as cardioprotective agents before the use of anthracyclines by adult oncologic patients.

RESULTS

After application of eligibility and selection criteria, eight articles were considered as high quality, complying with the proposed theme; all eight clinical trials, four of them placebo-controlled, with a total number of 655 patients included. From this sample, 281 (42.9%) used beta-blocker as intervention, and carvedilol was the most frequent (167 patients - 25.5%). Six studies were considered positive regarding the cardioprotection role played by beta-blockers, although only four demonstrated significant difference on left ventricle ejection fraction after chemotherapy on groups that used beta-blockers compared to control groups. Carvedilol and nebivolol, but not metoprolol, had positive results regarding cardioprotection. Other beta-blockers were not analysed in the selected studies.

CONCLUSIONS

Despite the potential cardioprotective effect of beta-blockers, as demonstrated in small and unicentric clinical trials, its routine use on prevention of anthracycline-associated cardiotoxicity demands greater scientific evidence.

Association of Interleukin-10 -1082A>G (rs1800896) Polymorphism with Predisposition to Breast Cancer: a Meta-Analysis based on 17 Case-Control Studies

SUMMARY INTRODUCTION The association between the between IL-10 -1082A>G (rs1800896) polymorphism and breast cancer has been evaluated by several number case-control studies. However, these studies might be underpowered to reveal the true association. OBJECTIVE We have performed a comprehensive meta-analysis to investigate the association IL-10 -1082A>G polymorphism and breast cancer. MATERIALS AND METHODS A systematic literature search was conducted using PubMed, Google Scholar, and Web of Science up to September 20, 2017. Data was analysed with CMA software to identify the strength of the association by pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS A total of 17 case-control studies involving 3275 cases and 3416 controls obtained from database searches were examined. Overall, there was no significant association between IL-10 -1082A>G polymorphism and breast cancer risk under all genetic models. No significant publication bias was found for the five genetic models (G vs. A OR = 1.184, 95% CI = 0.895-1.180, p= 0.230; GG vs. AA: OR = 1.430, 95% CI = 0.927-2.204, p= 0.106; GA vs. AA: OR = 0.966, 95% CI = 0.765-1.221, p= 0.774; GG+GA vs. AA: OR = 0.957, 95% CI = 0.697-1.314, p= 0.786; and GG vs. GA+AA: OR = 1.221, 95% CI = 0.981-1.518, p= 0.073). Moreover, there was no significant association between the IL-10 -1082A>G polymorphism and breast cancer risk by ethnicity. CONCLUSION Our findings indicated that IL-10 -1082A>G (rs1800896) polymorphism might not be a risk factor for the development of breast cancer.

Assessment of late anthracycline-induced cardiotoxicity by 123I-mIBG cardiac scintigraphy in patients treated during childhood and adolescence

PURPOSE

The goal of this study was to evaluate late cardiotoxic effects of anthracyclines (ATC) by evaluating cardiac sympathetic activity in a cohort of asymptomatic patients previously treated with ATC for childhood cancers.

METHODS

We studied 89 asymptomatic patients previously treated with ATC with a normal echocardiogram (49 men and 40 women) and a control group of 40 healthy individuals (26 men and 14 women). Both groups underwent planar myocardial 123I-meta-iodobenzylguanidine scintigraphy (123I-mIBG). From these images, the early and late heart-to-mediastinum (H/M) ratio and washout rate (WR) were assessed.

RESULTS

The mean survival at the time of the 123I-mIBG scintigraphy was 5.3 ± 3.4 years. Patients treated with ATC had a lower but clinical normal left ventricular ejection fraction (LVEF) compared to controls (60.44 ± 6.5 vs 64.1 ± 6.0%, P < 0.01). Both the late H/M ratio and WR were not able to discriminate ATC treated patients from controls. The cumulative ATC dose was the only independent predictor of the LVEF, explaining approximately 12% of the variation in LVEF (P = 0.01).

CONCLUSIONS

Although the pathophysiology behind ATC cardiotoxicity is most likely multifactorial, myocardial sympathetic activity is not associated with a reduction in LVEF 5-years after completion of chemotherapy.

Efficacy and safety of Dexrazoxane (DRZ) in sarcoma patients receiving high cumulative doses of anthracycline therapy - a retrospective study including 32 patients

BACKGROUND

Anthracyclines, as the most effective therapy, are the cornerstone of advanced stage sarcoma treatment. However, anthracyclines can also contribute to myocardial dysfunction and congestive heart failure, ultimately limiting the therapeutic potential of the drug. Coadministration of Dexrazoxane has been shown to effectively reduce cardiotoxicity, however primarily in patients suffering in diseases other than sarcoma.

METHODS

The aim of this retrospective analysis was to evaluate safety and efficacy of chemotherapy with high cumulative doses of anthracyclines in combination with Dexrazoxane. The medical charts of 32 patients treated in four institutions were analyzed. Reasons for coadministration were rechallenge, reaching the cumulative anthracycline dose and preexisting heart failure.

RESULTS

The median age was 54 years [18-68 years]. The median cumulative anthracycline dose before adding DRZ was 450 mg/m(2) and after administration of last anthracycline containing therapy 750 mg/m(2). Either during treatment or follow up, 2/27 patients (7 %) without preexisting major cardiac findings developed anthracycline-induced cardiotoxicity. The median overall survival (OS) from start of the first anthracycline containing chemotherapy was 46 months and 17 months from the initial coadministration of DRZ. At rechallenge, the median progression free survival (PFS) with DRZ was 7 months. In continuous therapy, the median PFS was 13 months from beginning of chemotherapy and 9 months from the addition of DRZ.

CONCLUSION

Chemotherapy with high cumulative doses of anthracyclines in addition with DRZ demonstrated a remarkable OS in these advanced disease patients. Cardiac side-effects due to high cumulative doses of anthracyclines requiring discontinuation of anthracycline treatment were rare. A PFS of 9 months from the beginning of the coadministration of DRZ indicates that continuing anthracycline therapy beyond established cumulative doses is a promising therapeutic option.

Cardiac complications in childhood cancer survivors treated with anthracyclines

Cardiovascular complications are among the leading causes of morbidity and mortality among survivors of childhood cancer, after cancer relapse and secondary malignancies. Although advances in cancer treatment have improved the 5-year survival rates, the same treatments, such as anthracyclines, that cure cancer also increase the risk for adverse cardiovascular effects. Anthracycline-related cardiotoxicity in survivors of childhood cancer is progressive and can take years to develop, initially presenting as sub-clinical cardiac abnormalities that, if left undetected or untreated, can lead to heart failure, myocardial infarction, or other clinical cardiac dysfunction. A higher cumulative dose of anthracycline is associated with cardiotoxicity in children; however, sub-clinical cardiac abnormalities are evident at lower doses with longer follow-up, suggesting that there is no "safe" dose of anthracycline. Other risk factors include female sex, younger age at diagnosis, black race, trisomy 21, longer time since treatment, and the presence of pre-existing cardiovascular disease and co-morbidities. Cardioprotective strategies during treatment are limited in children. Enalapril provides only temporary cardioprotection, whereas continuous anthracycline infusion extends none. On the other hand, dexrazoxane successfully prevents or reduces anthracycline-related cardiotoxicity in children with cancer, without increased risks for recurrence of primary or second malignancies or reductions in anti-tumour efficacy. With more childhood cancer survivors now reaching adulthood, it is vital to understand the adverse effects of cancer treatment on the cardiovascular system and their long-term consequences to identify and establish optimal prevention and management strategies that balance oncologic efficacy with long-term safety.

Oxidative stress on cardiotoxicity after treatment with single and multiple doses of doxorubicin

The mechanism of doxorubicin (DOX)-induced cardiotoxicity remains controversial. Wistar rats ( n = 66) received DOX injections intraperitoneally and were randomly assigned to 2 experimental protocols: (1) rats were killed before (−24 h, n = 8) and 24 h after (+24 h, n = 8) a single dose of DOX (4 mg/kg body weight) to determine the DOX acute effect and (2) rats ( n = 58) received 4 injections of DOX (4 mg/kg body weight/week) and were killed before the first injection (M0) and 1 week after each injection (M1, M2, M3, and M4) to determine the chronological effects. Animals used at M0 ( n = 8) were also used at moment −24 h of acute study. Cardiac total antioxidant performance (TAP), DNA damage, and morphology analyses were carried out at each time point. Single dose of DOX was associated with increased cardiac disarrangement, necrosis, and DNA damage (strand breaks (SBs) and oxidized pyrimidines) and decreased TAP. The chronological study showed an effect of a cumulative dose on body weight ( R = −0.99, p = 0.011), necrosis ( R = 1.00, p = 0.004), TAP ( R = 0.95, p = 0.049), and DNA SBs ( R = −0.95, p = 0.049). DNA SBs damage was negatively associated with TAP ( R = −0.98, p = 0.018), and necrosis ( R = −0.97, p = 0.027). Our results suggest that oxidative damage is associated with acute cardiotoxicity induced by a single dose of DOX only. Increased resistance to the oxidative stress is plausible for the multiple dose of DOX. Thus, different mechanisms may be involved in acute toxicity versus chronic toxicity.

Cardioprotective interventions for cancer patients receiving anthracyclines

BACKGROUND

Anthracyclines are among the most effective chemotherapeutic agents in the treatment of numerous malignancies. Unfortunately, their use is limited by a dose-dependent cardiotoxicity. In an effort to prevent this cardiotoxicity, different cardioprotective agents have been studied.

OBJECTIVES

The objective of this review was to assess the efficacy of different cardioprotective agents in preventing heart damage in cancer patients treated with anthracyclines.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 10), MEDLINE (1966 to November 2010) and EMBASE (1980 to November 2010) databases. In addition, we handsearched reference lists, conference proceedings of the International Society of Paediatric Oncology (SIOP) and American Society of Clinical Oncology (ASCO) meetings (1998 to 2010) and ongoing trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which any cardioprotective agent was compared to no additional therapy or placebo in cancer patients (children and adults) receiving anthracyclines.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and data extraction including adverse effects.

MAIN RESULTS

We identified RCTs for the eight cardioprotective agents N-acetylcysteine, phenethylamines, coenzyme Q10, a combination of vitamins E and C and N-acetylcysteine, L-carnitine, carvedilol, amifostine and dexrazoxane (mostly for adults with advanced breast cancer). All studies had methodological limitations and for the first seven agents there were too few studies to allow pooling of results. None of the individual studies showed a cardioprotective effect. The 10 included studies on dexrazoxane enrolled 1619 patients. The meta-analysis for dexrazoxane showed a statistically significant benefit in favour of dexrazoxane for the occurrence of heart failure (risk ratio (RR) 0.29, 95% CI 0.20 to 0.41). No evidence was found for a difference in response rate or survival between the dexrazoxane and control groups. The results for adverse effects were ambiguous. No significant difference in the occurrence of secondary malignancies was identified.

AUTHORS' CONCLUSIONS

No definitive conclusions can be made about the efficacy of cardioprotective agents for which pooling of results was impossible. Dexrazoxane prevents heart damage and no evidence for a difference in response rate or survival between the dexrazoxane and control groups was identified. The evidence available did not allow us to reach any definite conclusions about adverse effects. We conclude that if the risk of cardiac damage is expected to be high, it might be justified to use dexrazoxane in patients with cancer treated with anthracyclines. However, clinicians should weigh the cardioprotective effect of dexrazoxane against the possible risk of adverse effects for each individual patient.

Effect of hypothermia on doxorubicin-induced cardiac myoblast signaling and cell death

BACKGROUND

Anthracyclines (AC) are useful chemotherapeutic agents whose principal limitation is cardiac toxicity, which may progress to heart failure, transplantation or even death. We have shown that this toxicity involves oxidative stress-induced activation of the DNA damage pathway. Hypothermia has been shown to be protective against other diseases involving oxidative stress but has not been studied in models of AC toxicity.

METHODS

In the current experiments, H9C2 cardiac myoblasts were treated with varying concentrations of the AC doxorubicin (DOX) during normothermia (37°C) or mild hypothermia (35°C). Total cell death was assayed using trypan blue exclusion and apoptosis by terminal deoxynucleotidyl transferase-mediated deoxyuridine-biotin nick end labeling (TUNEL) staining. Oxidative stress was assayed using the fluorescent indicator 2'7'-dichlorofluorescein diacetate. DNA damage pathway activation was assayed by immunostaining for H2AX and p53. Mitochondrial membrane potential was assayed by JC-1 staining.

RESULTS

At all concentrations of DOX examined (1, 2.5 and 5 μM), hypothermia reduced oxidative stress, activation of H2AX and p53, loss of mitochondrial membrane potential and total and apoptotic cell death (P=.001-.03 for each observation).

CONCLUSIONS

The reduction of oxidative stress-induced activation of the DNA damage pathway and consequent cell death by mild hypothermia supports a possible protective role to reduce the clinical impact of DOX-induced cardiac toxicity. Such an approach may allow expanded use of these effective chemotherapeutic agents to increase cancer cure rates.

Subclinical cardiac dysfunction and exercise performance in childhood cancer survivors

BACKGROUND

Although anthracycline cardiotoxicity is clearly related to the cumulative dose administered, subclinical cardiac dysfunction has been reported across a wide range of treatment regimens, and its clinical significance is still unclear. Purpose of this study is to investigate by exercise echocardiography for subclinical cardiac dysfunction in survivors of pediatric cancer treated with low-moderate anthracycline doses, and to evaluate whether it may alter the response of the cardiovascular system to dynamic exercise.

PROCEDURE

Post-exercise left ventricular end-systolic wall stress (ESS), left ventricular posterior wall dimension and percent thickening at end systole, and cardiopulmonary exercise test-derived indexes of cardiac function were examined in 55 apparently healthy patients (mean age 13.5 ± 2.9 years, median anthracycline cumulative dose 240 mg/m(2)) and in 63 controls.

RESULTS

Subclinical cardiac dysfunction was identified in 17 patients (30%) presenting reduced left ventricular posterior wall dimension or percent thickening, or increased values of left ventricular ESS as compared to controls (group A), while the remaining patients formed group B. Reduced oxygen consumption at peak exercise in both groups of patients was the only cardiopulmonary exercise test variable resulting significantly different between patients and controls: no differences were found among the groups of patients.

CONCLUSIONS

Our results confirm that even patients treated with a median anthracycline dose of 240 mg/m(2) (range 100-490) are at considerable risk of exhibiting subclinical cardiac dysfunction that, however, does not seem to alter the physiologic response of the cardiovascular system to dynamic exercise.

Differences in Effects on Myocardium and Mitochondria by Angiogenic Inhibitors Suggest Separate Mechanisms of Cardiotoxicity

Several multikinase angiogenesis inhibitors demonstrate mitochondrial and/or cardiovascular toxicity, suggesting an on-target pharmacologic effect. To evaluate whether cardiotoxicity is directly related to vascular endothelial growth factor receptor inhibition, we investigated the effects of sunitinib, sorafenib, and pazopanib on myocardial function and structure. We used a rat model to assess myocardial effects of the inhibitors concurrently exposed to the cardiac stressor dobutamine. Echocardiographic abnormalities including premature ventricular contractions, decreases in heart rate, circumferential strain, and radial and circumferential strain rates were noted with sorafenib, but not with sunitinib or pazopanib. Ultrastructural analysis of ventricular cardiomyocytes by transmission electron microscopy revealed mitochondrial swelling, dense deposits, and matrix cavitation in rats given sunitinib and disrupted mitochondrial cristae in rats given sorafenib, but there were no effects with pazopanib. Effects on neonatal rat cardiomyocyte cultures were assessed, which identified decreases in mitochondrial membrane potential with sunitinib treatment, but not with sorafenib or pazopanib. Intracellular adenosine triphosphate depletion was observed with sunitinib and sorafenib, but not pazopanib. Our results show that cardiotoxicity is not necessarily related to a pharmacologic classwide effect of vascular endothelial growth factor receptor inhibition, and the rat myocardial structural and functional changes identified in this study may be instead a result of inhibition of other kinase pathways, the mechanism of which may be associated with mitochondrial toxicity.

Cardiac lesions induced by testosterone: protective effects of dexrazoxane and trimetazidine

Further to our previous observation of post-mortem cardiac lesions after sudden death in several athletes with a history of anabolic steroid abuse, this study was intended to reproduce these lesions in rabbits administered testosterone oenanthate, a prototypic anabolic steroid abused by athletes, and to provide evidence for the protective effects of trimetazidine and dexrazoxane that are used as antianginal and cardioprotective drugs, respectively. Groups of six rabbits each were administered saline, testosterone, or a combination of testosterone and either trimetazidine or dexrazoxane for 3 months. Histologic cardiac lesions including necrosis, misshapen cell nuclei, interstitial and endocardial fibrosis, lymphocytic infiltrates, and vascular dystrophies were observed in testosterone-treated rabbits. In contrast, no significant lesions were observed in the animals treated with testosterone combined with either trimetazidine or dexrazoxane. This is the first study providing evidence for testosterone cardiotoxicity following sub-chronic exposure in laboratory animals. In addition, these results suggest the protective role of trimetazidine and dexrazoxane.

Cardioprotective interventions for cancer patients receiving anthracyclines

BACKGROUND

Anthracyclines are among the most effective chemotherapeutic agents in the treatment of numerous malignancies. Unfortunately, their use is limited by a dose-dependent cardiotoxicity. In an effort to prevent this cardiotoxicity, different cardioprotective agents have been studied.

OBJECTIVES

The objective of this review was to assess the efficacy of different cardioprotective agents in preventing heart damage in cancer patients treated with anthracyclines.

SEARCH STRATEGY

We searched the databases of the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2, 2007), MEDLINE (1966 to April 2007) and EMBASE (1980 to April 2007). In addition, we handsearched reference lists and conference proceedings of the SIOP and ASCO meetings (1998 to 2006).

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which any cardioprotective agent was compared to no additional or placebo therapy in cancer patients (children and adults) receiving anthracyclines.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, quality assessment and data-extraction including adverse effects.

MAIN RESULTS

We identified RCTs for seven cardioprotective agents: N-acetylcysteine, phenetylamines, coenzyme Q10, combination of vitamins E and C and N-acetylcysteine, L-carnitine, carvedilol and dexrazoxane (mostly adults with advanced breast cancer). All studies had methodological limitations. For the first six agents, there were too few studies to allow pooling of results. None of the individual studies showed a cardioprotective effect. The nine included studies of dexrazoxane enrolled 1403 patients. The meta-analysis of dexrazoxane showed a statistically significant benefit in favour of dexrazoxane for the occurrence of heart failure (Relative Risk (RR) 0.29, 95% CI 0.20 to 0.41). No evidence was found for a difference in response rate or survival between the dexrazoxane and control group. Only for one adverse effect (abnormal white blood cell count at nadir) a difference in favour of the control group was identified.

AUTHORS' CONCLUSIONS

For cardioprotective agents for which pooling was impossible, no definitive conclusions can be made about their efficacy. Dexrazoxane prevents heart damage and no evidence for a difference in response rate or survival between the dexrazoxane and control group was identified. Only for an abnormal white blood cell count at nadir a clearly significant difference in favour of the control group was identified. We conclude that if the risk of cardiac damage is expected to be high, it might be justified to use dexrazoxane in patients with cancer treated with anthracyclines. However, for each individual patient clinicians should weigh the cardioprotective effect of dexrazoxane against the possible risk of adverse effects.

Adjuvant and neoadjuvant combination chemotherapy for osteogenic sarcoma

PURPOSE OF REVIEW

The most recent developments regarding chemotherapy treatment of osteogenic sarcoma are reviewed, with special emphasis on prospective clinical trials and evaluations of late effects of chemotherapy.

RECENT FINDINGS

In recent years, clinical research has essentially focused on possible refinements of the classic four-drug (methotrexate, cisplatin, doxorubicin and ifosfamide) therapy rather than investigating new drugs. It has been demonstrated that dose-intensification does not improve prognosis. Many investigators have evaluated late chemotherapy-related side effects, particularly in terms of cardiac, renal and auditive toxicity, risk of infertility and of second tumors. Recent findings recommend further studies to define the role of the immunostimulating agent muramyl tripeptide-phosphatidilethanolamine in osteosarcoma. Preclinical and phase II studies suggest an activity of mammalian target of rapamycin (mTOR) inhibitors in osteosarcoma, which also deserves further clinical studies.

SUMMARY

At present, patients with nonmetastatic osteosarcoma of the extremity aged less than 40 years have an expected 5-year survival rate of 70% with a chemotherapy regimen based on methotrexate, cisplatin, doxorubicin and ifosfamide. Further improvement cannot be achieved by dose intensification of treatment and new strategies are required. Prolonged follow-up is mandatory due to the risk of late effects, second tumors and late relapse from osteosarcoma.

Effect of Lycopene on Doxorubicin-Induced Cardiotoxicity: An Echocardiographic, Histological and Morphometrical Assessment

Doxorubicin is an excellent chemotherapeutic agent utilized for several types of cancer but the irreversible doxorubicin-induced cardiac damage is the major limitation for its use. Oxidative stress seems to be associated with some phase of the toxicity mechanism process. To determine if lycopene protects against doxorubicin-induced cardiotoxicity, male Wistar rats were randomly assigned either to control, lycopene, doxorubicin or doxorubicin + lycopene groups. They received corn oil (control, doxorubicin) or lycopene (5 mg/kg body weight a day) (lycopene, doxorubicin + lycopene) by gavage for a 7-week period. They also received saline (control, lycopene) or doxorubicin (4 mg/kg) (doxorubicin, doxorubin + lycopene) intraperitoneally by week 3, 4, 5 and 6. Animals underwent echocardiogram and were killed for tissue analyses by week 7. Mean lycopene levels (nmol/kg) in liver were higher in the doxorubicin + lycopene group (5822.59) than in the lycopene group (2496.73), but no differences in lycopene were found in heart or plasma of these two groups. Lycopene did not prevent left ventricular systolic dysfunction induced by doxorubicin. However, morphologic examination revealed that doxorubicin-induced myocyte damage was significantly suppressed in rats treated with lycopene. Doxorubicin treatment was followed by increase of myocardium interstitial collagen volume fraction. Our results show that: (i) doxorubicin-induced cardiotoxicity was confirmed by echocardiogram and morphological evaluations; (ii) lycopene absorption was confirmed by its levels in heart, liver and plasma; (iii) lycopene supplementation provided myocyte protection without preventing interstitial collagen accumulation increase; (iv) doxorubicin-induced cardiac dysfunction was not prevented by lycopene supplementation; and (v) lycopene depletion was not observed in plasma and tissues from animals treated with doxorubicin.

A Cannabinoid Anticancer Quinone, HU-331, Is More Potent and Less Cardiotoxic Than Doxorubicin: A Comparative in Vivo Study

Several quinones have been found to be effective in the treatment of some forms of cancer; however, their cumulative heart toxicity limits their use. The cannabinoid quinone HU-331 [3S,4R-p-benzoquinone-3-hydroxy-2-p-mentha-(1,8)-dien-3-yl-5-pentyl] is highly effective against tumor xenografts in nude mice. We report now a comparison of the anticancer activity of HU-331 and its cardiotoxicity with those of doxorubicin in vivo. General toxicity was assayed in Sabra, nude and SCID-NOD mice. The anticancer activity in vivo was assessed by measurement of the tumors with an external caliper in HT-29 and Raji tumor-bearing mice and by weighing the excised tumors. Left ventricular function was evaluated with transthoracic echocardiography. Myelotoxicity was evaluated by blood cell count. Cardiac troponin T (cTnT) plasma levels were determined by immunoassay. HU-331 was found to be much less cardiotoxic than doxorubicin. The control and the HU-331-treated groups gained weight, whereas the doxorubicin-treated group lost weight during the study. In HT-29 colon carcinoma, the tumor weight in the HU-331-treated group was 54% smaller than in the control group and 30% smaller than in the doxorubicin-treated group. In Raji lymphoma, the tumor weight in the HU-331-treated group was 65% smaller than in the control group and 33% smaller than in the doxorubicin-treated group. In contrast to doxorubicin, HU-331 did not generate reactive oxygen species in mice hearts (measured by protein carbonylation levels and malondialdehyde levels). In vivo, HU-331 was more active and less toxic than doxorubicin and thus it has a high potential for development as a new anticancer drug.