Carvedilol-mediated antioxidant protection against doxorubicin-induced cardiac mitochondrial toxicity

Pediatric Cardio-Oncology: Screening, Risk Stratification, and Prevention of Cardiotoxicity Associated with Anthracyclines

Anthracyclines have significantly improved the survival of children with malignant tumors, but the associated cardiotoxicity, an effect now under the purview of pediatric cardio-oncology, due to its cumulative and irreversible effects on the heart, limits their clinical application. A systematic screening and risk stratification approach provides the opportunity for early identification and intervention to mitigate, reverse, or prevent myocardial injury, remodeling, and dysfunction associated with anthracyclines. This review summarizes the risk factors, surveillance indexes, and preventive strategies of anthracycline-related cardiotoxicity to improve the safety and efficacy of anthracyclines.

Intranasal Delivery of Carvedilol- and Quercetin-Encapsulated Cationic Nanoliposomes for Cardiovascular Targeting: Formulation and In Vitro and Ex Vivo Studies

Carvedilol (CVD), an adrenoreceptor blocker, is a hydrophobic Biopharmaceutics Classification System class II drug with poor oral bioavailability due to which frequent dosing is essential to attain pharmacological effects. Quercetin (QC), a polyphenolic compound, is a potent natural antioxidant, but its oral dosing is restricted due to poor aqueous solubility and low oral bioavailability. To overcome the common limitations of both drugs and to attain synergistic cardioprotective effects, we formulated CVD- and QC-encapsulated cationic nanoliposomes (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. We designed CVD- and QC-loaded cationic nanoliposomal (NLPs) in situ gel (CVD/QC-L.O.F.) for intranasal administration. In vitro drug release studies of CVD/QC-L.O.F. (16.25%) exhibited 18.78 ± 0.57% of QC release and 91.38 ± 0.93% of CVD release for 120 h. Ex vivo nasal permeation studies of CVD/QC-L.O.F. demonstrated better permeation of QC (within 96 h), i.e., 75.09% compared to in vitro drug release, whereas CVD permeates within 48 h, indicating the better interaction between cationic NLPs and the negatively charged biological membrane. The developed nasal gel showed a sufficient mucoadhesive property, good spreadability, higher firmness, consistency, and cohesiveness, indicating suitability for membrane application and intranasal administration. CVD-NLPs, QC-NLPs, and CVD/QC-NLPs were evaluated for in vitro cytotoxicity, in vitro ROS-induced cell viability assessment, and a cellular uptake study using H9c2 rat cardiomyocytes. The highest in vitro cellular uptake of CVD/QC-cationic NLPs by H9c2 cells implies the benefit of QC loading within the CVD nanoliposomal carrier system and gives evidence for better interaction of NLPs carrying positive charges with the negatively charged biological cells. The in vitro H2O2-induced oxidative stress cell viability assessment of H9c2 cells established the intracellular antioxidant activity and cardioprotective effect of CVD/QC-cationic NLPs with low cytotoxicity. These findings suggest the potential of cationic NLPs as a suitable drug delivery carrier for CVD and QC combination for the intranasal route in the treatment of various cardiovascular diseases like hypertension, angina pectoris, etc. and for treating neurodegenerative disorders.

Mechanisms of Cardiovascular Toxicities Induced by Cancer Therapies and Promising Biomarkers for Their Prediction: A Scoping Review

AIM

With the advancement of anti-cancer medicine, cardiovascular toxicities due to cancer therapies are common in oncology patients, resulting in increased mortality and economic burden. Cardiovascular toxicities caused by cancer therapies include different severities of cardiomyopathy, arrhythmia, myocardial ischaemia, hypertension, and thrombosis, which may lead to left ventricular dysfunction and heart failure. This scoping review aimed to summarise the mechanisms of cardiovascular toxicities following various anti-cancer treatments and potential predictive biomarkers for early detection.

METHODS

PubMed, Cochrane, Embase, Web of Science, Scopus, and CINAHL databases were searched for original studies written in English related to the mechanisms of cardiovascular toxicity induced by anti-cancer therapies, including chemotherapy, targeted therapy, immunotherapy, radiation therapy, and relevant biomarkers. The search and title/abstract screening were conducted independently by two reviewers, and the final analysed full texts achieved the consensus of the two reviewers.

RESULTS

A total of 240 studies were identified based on their titles and abstracts. In total, 107 full-text articles were included in the analysis. Cardiomyocyte and endothelial cell apoptosis caused by oxidative stress injury, activation of cell apoptosis, blocking of normal cardiovascular protection signalling pathways, overactivation of immune cells, and myocardial remodelling were the main mechanisms. Promising biomarkers for anti-cancer therapies related to cardiovascular toxicity included placental growth factor, microRNAs, galectin-3, and myeloperoxidase for the early detection of cardiovascular toxicity.

CONCLUSION

Understanding the mechanisms of cardiovascular toxicity following various anti-cancer treatments could provide implications for future personalised treatment methods to protect cardiovascular function. Furthermore, specific early sensitive and stable biomarkers of cardiovascular system damage need to be identified to predict reversible damage to the cardiovascular system and improve the effects of anti-cancer agents.

Approaches for reducing chemo/radiation-induced cardiotoxicity by nanoparticles

Nanoparticles are fascinating and encouraging carriers for cancer treatment due to their extraordinary properties and potential applications in targeted drug delivery, treatment, and diagnosis. Experimental studies including in vitro and in vivo examinations show that nanoparticles can cause a revolution in different aspects of cancer therapy. Normal tissue toxicity and early and late consequences are the major limitations of cancer therapy by radiotherapy and chemotherapy. However, the delivery of drugs into tumors or reducing the accumulation of drugs in normal tissues can permit a more satisfactory response of malignancies to therapy with more inferior side effects. Cardiac toxicity is one of the major problems for chemotherapy and radiotherapy. Therefore, several experimental studies have been performed to minimize the degenerative impacts of cancer treatment on the heart and also enhance the influences of radiotherapy and chemotherapy agents in cancers. This review article emphasizes the benefits of nanoparticle-based drug delivery techniques, including minimizing the exposure of the heart to anticancer drugs, enhancing the accumulation of drugs in cancers, and expanding the effectiveness of radiotherapy. The article also discusses the challenges and problems accompanied with nanoparticle-based drug delivery techniques such as toxicity, which need to be addressed through further research. Moreover, the article emphasizes the importance of developing safe and effective nanoparticle-based therapies that can be translated into clinical practice.

Heartbreaker: Detection and prevention of cardiotoxicity in hematological malignancies

Cancer survivors are at significant risk of cardiovascular (CV) morbidity and mortality; patients with hematologic malignancies have a higher rate of death due to heart failure compared to all other cancer subtypes. The majority of conventional hematologic cancer treatments is associated with increased risk of acute and long-term CV toxicity. The incidence of cancer therapy induced CV toxicity depends on the combination of patient characteristics and on the type, dose, and duration of the therapy. Early diagnosis of CV toxicity, appropriate referral, more specific cardiac monitoring follow-up and timely interventions in target patients can decrease the risk of CV adverse events, the interruption of oncological therapy, and improve the patient's prognosis. Herein, we summarize the CV effects of conventional treatments used in hematologic malignancies with a focus on definitions and incidence of the most common CV toxicities, guideline recommended early detection approaches, and preventive strategies before and during cancer treatments.

The Role of Nrf2 and Inflammation on the Dissimilar Cardiotoxicity of Doxorubicin in Two-Time Points: a Cardio-Oncology In Vivo Study Through Time

Doxorubicin (DOX) is a topoisomerase II inhibitor used in cancer therapy. Despite its efficacy, DOX causes serious adverse effects, such as short- and long-term cardiotoxicity. This work aimed to assess the short- and long-term cardiotoxicity of DOX and the role of inflammation and antioxidant defenses on that cardiotoxicity in a mice model. Adult CD-1 male mice received a cumulative dose of 9.0 mg/kg of DOX (2 biweekly intraperitoneal injections (ip), for 3 weeks). One week (1W) or 5 months (5M) after the last DOX administration, the heart was collected. One week after DOX, a significant increase in p62, tumor necrosis factor receptor (TNFR) 2, glutathione peroxidase 1, catalase, inducible nitric oxide synthase (iNOS) cardiac expression, and a trend towards an increase in interleukin (IL)-6, TNFR1, and B-cell lymphoma 2 associated X (Bax) expression was observed. Moreover, DOX induced a decrease on nuclear factor erythroid-2 related factor 2 (Nrf2) cardiac expression. In both 1W and 5M, DOX led to a high density of infiltrating M1 macrophages, but only the 1W-DOX group had a significantly higher number of nuclear factor κB (NF-κB) p65 immunopositive cells. As late effects (5M), an increase in Nrf2, myeloperoxidase, IL-33, tumor necrosis factor-α (TNF-α), superoxide dismutase 2 (SOD2) expression, and a trend towards increased catalase expression were observed. Moreover, B-cell lymphoma 2 (Bcl-2), cyclooxygenase-2 (COX-2), and carbonylated proteins expression decreased, and a trend towards decreased p38 mitogen-activated protein kinase (MAPK) expression were seen. Our study demonstrated that DOX induces adverse outcome pathways related to inflammation and oxidative stress, although activating different time-dependent response mechanisms.

The role of inflammation and antioxidant defenses in the cardiotoxicity of doxorubicin in elderly CD-1 male mice

Doxorubicin (DOX) is a potent chemotherapeutic agent used against several cancer types. However, due to its cardiotoxic adverse effects, the use of this drug may be also life-threatening. Although most cancer patients are elderly, they are poorly represented and evaluated in pre-clinical and clinical studies. Considering this, the present work aims to evaluate inflammation and oxidative stress as the main mechanisms of DOX-induced cardiotoxicity, in an innovative approach using an experimental model constituted of elderly animals treated with a clinically relevant human cumulative dose of DOX. Elderly (18-20 months) CD-1 male mice received biweekly DOX administrations, for 3 weeks, to reach a cumulative dose of 9.0 mg/kg. One week (1W) or two months (2 M) after the last DOX administration, the heart was collected to determine both drug's short and longer cardiac adverse effects. The obtained results showed that DOX causes cardiac histological damage and fibrosis at both time points. In the 1W-DOX group, the number of nuclear factor kappa B (NF-κB) p65 immunopositive cells increased and a trend toward increased NF-κB p65 expression was seen. An increase of inducible nitric oxide synthase (iNOS) and interleukin (IL)-33 and a trend toward increased IL-6 and B-cell lymphoma-2-associated X (Bax) expression were seen after DOX. In the same group, a decrease in IL-1β, p62, and microtubule-associated protein 1A/1B-light chain 3 (LC3)-I, p38 mitogen-activated protein kinase (MAPK) expression was observed. Contrariwise, the animals sacrificed 2 M after DOX showed a significant increase in glutathione peroxidase 1 and Bax expression with persistent cardiac damage and fibrosis, while carbonylated proteins, erythroid-2-related factor 2 (Nrf2), NF-κB p65, myeloperoxidase, LC3-I, and LC3-II expression decreased. In conclusion, our study demonstrated that in an elderly mouse population, DOX induces cardiac inflammation, autophagy, and apoptosis in the heart in the short term. When kept for a longer period, oxidative-stress-linked pathways remained altered, as well as autophagy markers and tissue damage after DOX treatment, emphasizing the need for continuous post-treatment cardiac monitoring.

Remyelinating activities of Carvedilol or alpha lipoic acid in the Cuprizone-Induced rat model of demyelination

Multiple sclerosis (MS) is a complex and multifactorial neurodegenerative disease with unknown etiology, MS is featured by multifocal demyelinated lesions distributed throughout the brain. It is assumed to result from an interaction between genetic and environmental factors, including nutrition. Therefore, different therapeutic approaches are aiming to stimulate remyelination which could be defined as an endogenous regeneration and repair of myelin in the central nervous system. Carvedilol is an adrenergic receptor antagonist. Alpha lipoic acid (ALA) is a well-known antioxidant. Herein, we investigated the remyelination potential of Carvedilol or ALA post-Cuprizone (CPZ) intoxication. Carvedilol or ALA (20 mg/kg/d) was administrated orally for two weeks at the end of the five weeks of CPZ (0.6%) administration. CPZ provoked demyelination, enhanced oxidative stress, and stimulated neuroinflammation. Histological investigation of CPZ-induced brains showed obvious demyelination in the corpus callosum (CC). Both Carvedilol and ALA demonstrated remyelinating activities, with corresponding upregulation of the expression of MBP and PLP, the major myelin proteins, downregulation of the expression of TNF-α and MMP-9, and decrement of serum IFN-γ levels. Moreover, both Carvedilol and ALA alleviated oxidative stress, and ameliorated muscle fatigue. This study highlights the neurotherapeutic potential of Carvedilol or ALA in CPZ-induced demyelination, and offers a better model for the exploring of neuroregenerative strategies. The current study is the first to demonstrate a pro-remyelinating activity for Carvedilol, as compared to ALA, which might represent a potential additive benefit in halting demyelination and alleviating neurotoxicity. However, we could declare that Carvedilol showed a lower neuroprotective potential than ALA.

Repurposing of carvedilol to alleviate lung fibrosis in rats: Repressing of TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions

Idiopathic pulmonary fibrosis (IPF) is the most widely studied interstitial lung disease. IPF eventually leads to respiratory insufficiency, lung cancer, and death. Carvedilol (CAR) is a third-generation β-adrenergic receptor antagonist with α1-blocking effect. CAR demonstrates antifibrotic activities in various experimental models of organ fibrosis.

AIMS

This work is designed to explore the possible alleviating effects of CAR on bleomycin (BLM)-induced lung fibrosis in rats.

MAIN METHODS

The BLM rat model of lung fibrosis was achieved by intratracheal delivery of a single dose of 5 mg/kg of BLM. Seven days following BLM injection, either prednisolone or CAR was orally administered at doses of 10 mg/kg once daily for 21 days to rats. The actions of CAR were evaluated by lung oxidant/antioxidant parameters, protein concentration and total leucocyte count (TLC) in bronchoalveolar lavage fluid (BALF), fibrosis regulator-related genes along with the coexistent lung histological changes.

KEY FINDINGS

CAR effectively decreased lung malondialdehyde level, increased superoxide dismutase activity, declined both protein concentration and TLC in BALF, downregulated TGF-β1/α-SMA/Smad2/3 and STAT3 gene expressions, and repaired the damaged lung tissues.

SIGNIFICANCE

CAR conferred therapeutic potential against BLM-induced lung fibrosis in rats, at least in part, to its antioxidant, anti-inflammatory, and antifibrotic activities. CAR could be utilized as a prospective therapeutic option in patients with lung fibrosis in clinical practice.

Endothelial-to-Mesenchymal Transition: Potential Target of Doxorubicin-Induced Cardiotoxicity

The use of chemotherapeutic agents is becoming more frequent as the proportion of new oncology patients increases worldwide, with prolonged survival after treatment. As one of the most popular chemotherapy drugs, doxorubicin plays a substantial role in the treatment of tumors. Unfortunately, the use of doxorubicin is associated with several adverse effects, particularly severe cardiotoxicity that can be life-threatening, which greatly limits its clinical use. For decades, scientists have tried to explore many cardioprotective agents and therapeutic approaches, but their efficacy remains controversial, and some drugs have even brought about significant adverse effects. The concrete molecular mechanism of doxorubicin-induced cardiotoxicity is still to be unraveled, yet endothelial damage is gradually being identified as an important mechanism triggering the development and progression of doxorubicin-induced cardiotoxicity. Endothelial-to-mesenchymal transition (EndMT), a fundamental process regulating morphogenesis in multicellular organisms, is recognized to be associated with endothelial damage repair and acts as an important factor in the progression of cardiovascular diseases, tumors, and rheumatic immune diseases. Mounting evidence suggests that endothelial-mesenchymal transition may play a non-negligible role in doxorubicin-induced cardiotoxicity. In this paper, we reviewed the molecular mechanisms and signaling pathways of EndMT and outlined the molecular mechanisms of doxorubicin-induced cardiotoxicity and the current therapeutic advances. Furthermore, we summarized the basic principles of doxorubicin-induced endothelial-mesenchymal transition that lead to endothelial dysfunction and cardiotoxicity, aiming to provide suggestions or new ideas for the prevention and treatment of doxorubicin-induced endothelial and cardiac injury.

Cardio-Oncology: Mechanisms, Drug Combinations, and Reverse Cardio-Oncology

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy have brought hope to cancer patients. With the prolongation of survival of cancer patients and increased clinical experience, cancer-therapy-induced cardiovascular toxicity has attracted attention. The adverse effects of cancer therapy that can lead to life-threatening or induce long-term morbidity require rational approaches to prevention and treatment, which requires deeper understanding of the molecular biology underpinning the disease. In addition to the drugs used widely for cardio-protection, traditional Chinese medicine (TCM) formulations are also efficacious and can be expected to achieve “personalized treatment” from multiple perspectives. Moreover, the increased prevalence of cancer in patients with cardiovascular disease has spurred the development of “reverse cardio-oncology”, which underscores the urgency of collaboration between cardiologists and oncologists. This review summarizes the mechanisms by which cancer therapy induces cardiovascular toxicity, the combination of antineoplastic and cardioprotective drugs, and recent advances in reverse cardio-oncology.

Ethanol extracts of Rhaponticum uniflorum (L.) DC flowers attenuate doxorubicin-induced cardiotoxicity via alleviating apoptosis and regulating mitochondrial dynamics in H9c2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Loulu flowers (LLF) is the inflorescence of Rhaponticum uniflorum (L.) DC. (R. uniflorum), a member of the Compositae family. This plant possesses heat-clearing properties, detoxification effects, and is therefore frequently used for the treatment of cardiovascular diseases.

AIM OF THIS STUDY

This study aimed to investigate the cardioprotective effects of ethanol extracts of LLF against doxorubicin (DOX)-induced cardiotoxicity and explore the associated mechanisms.

MATERIAL AND METHODS

Ethanol extracts of LLF were prepared and analyzed by LC-ESI-MS/MS. DOX-treated H9c2 cells and DOX-treated zebrafish models were used to explore the cardioprotective effect of ethanol extracts on myocardial function. The effects of LLF on DOX-induced cytotoxicity in H9c2 cells were investigated by MTT assay. Reactive Oxygen Species (ROS) levels, mitochondrial membrane potential (MMP), and nuclear translocation of NF-κB p65 were examined using fluorescent probes. The expression level of Bax, Bcl-2, PARP, caspase-3, cleaved-caspase3, caspase9, IκBα, p-IκBα, IKK, p-IKK, p65, p-p65, OPA1, Mfn1, MFF and Fis 1 and GAPDH was determined by western blotting.

RESULTS

Twenty-five compounds were detected in ethanol extracts of LLF, include Nicotinamide, Coumarin, Parthenolide, and Ligustilide. Pre-treatment with LLF attenuated the DOX-induced decrease in viability and ROS production in H9c2 cells. Moreover, LLF treatment maintained the mitochondrial membrane integrity and suppressed apoptosis by upregulating expression level of Bcl-2 and downregulating the expression level of Bax, cleaved-caspase-3, cleaved-caspase-9 and cleaved-PARP. In addition, LLF significantly inhibited the DOX-induced activation of NF-κB signaling. Cells treated with DOX showed aberrant expression of mitochondrial dynamics related proteins, and these effects were alleviated by LLF pre-treatment. In conclusion, these results show that LLF can alleviate DOX-induced cardiotoxicity by blocking NF-κB signaling and re-balancing mitochondrial dynamics.

CONCLUSION

Ethanol extracts of LLF is a potential treatment option to against DOX-induced cardiotoxicity.

Reversal of Doxorubicin-Induced Bone Loss and Mineralization by Supplementation of Resveratrol and MitoTEMPO in the Early Development of Sparus aurata

Doxorubicin is a widely used chemotherapeutic drug known to induce bone loss. The mechanism behind doxorubicin-mediated bone loss is unclear, but oxidative stress has been suggested as a potential cause. Antioxidants that can counteract the toxic effect of doxorubicin on the bone would be helpful for the prevention of secondary osteoporosis. We used resveratrol, a natural antioxidant, and MitoTEMPO, a mitochondria-targeted antioxidant, to counteract doxorubicin-induced bone loss and mineralization on Sparus aurata larvae. Doxorubicin supplemented Microdiets increased bone deformities, decreased mineralization, and lipid peroxidation, whereas Resveratrol and MitoTEMPO supplemented microdiets improved mineralization, decreased bone deformities, and reversed the effects of doxorubicin in vivo and in vitro, using osteoblastic VSa13 cells. Partial Least-Squares Discriminant Analysis highlighted differences between groups on the distribution of skeletal anomalies and mineralization of skeleton elements. Calcium and Phosphorus content was negatively affected in the doxorubicin supplemented group. Doxorubicin reduced the mRNA expression of antioxidant genes, including catalase, glutathione peroxidase 1, superoxide dismutase 1, and hsp90 suggesting that ROS are central for Doxorubicin-induced bone loss. The mRNA expression of antioxidant genes was significantly increased on resveratrol alone or combined treatment. The length of intestinal villi was increased in response to antioxidants and reduced on doxorubicin. Antioxidant supplements effectively prevent bone deformities and mineralization defects, increase antioxidant response and reverse doxorubicin-induced effects on bone anomalies, mineralization, and oxidative stress. A combined treatment of doxorubicin and antioxidants was beneficial in fish larvae and showed the potential for use in preventing Doxorubicin-induced bone impairment.

Intelligent Nanomedicine Approaches Using Medical Gas-Mediated Multi-Therapeutic Modalities Against Cancer

The emerging area of gas-mediated cancer treatment has received widespread attention in the medical community. Featuring unique physical, chemical, and biological properties, nanomaterials can facilitate the delivery and controllable release of medicinal gases at tumor sites, and also serve as ideal platforms for the integration of other therapeutic modalities with gas therapy to augment cancer therapeutic efficacy. This review presents an overview of anti-cancer mechanisms of several therapeutic gases: nitric oxide (NO), hydrogen sulfide (H₂S), carbon monoxide (CO), oxygen (O₂), and hydrogen (H₂). Controlled release behaviors of gases under different endogenous and exogenous stimuli are also briefly discussed, followed by their synergistic effects with different therapeutic modes. Moreover, the potential challenges and future prospects regarding gas therapy based on nanomaterials are also described, aiming to facilitate the advancement of gas therapeutic nanomedicine in new frontiers for highly efficient cancer treatment.

Role of Inflammation and Redox Status on Doxorubicin-Induced Cardiotoxicity in Infant and Adult CD-1 Male Mice

Doxorubicin (DOX) is a topoisomerase II inhibitor commonly used in the treatment of several types of cancer. Despite its efficacy, DOX can potentially cause fatal adverse effects, like cardiotoxicity. This work aimed to assess the role of inflammation in DOX-treated infant and adult mice and its possible link to underlying cardiotoxicity. Two groups of CD-1 male mice of different ages (infants or adults) were subjected to biweekly DOX administrations, to reach a cumulative dose of 18.0 mg/kg, which corresponds approximately in humans to 100.6 mg/m2 for infants and 108.9 mg/m2 for adults a clinically relevant dose in humans. The classic plasmatic markers of cardiotoxicity increased, and that damage was confirmed by histopathological findings in both groups, although it was higher in adults. Moreover, in DOX-treated adults, an increase of cardiac fibrosis was observed, which was accompanied by an increase in specific inflammatory parameters, namely, macrophage M1 and nuclear factor kappa B (NF-κB) p65 subunit, with a trend toward increased levels of the tumor necrosis factor receptor 2 (TNFR2). On the other hand, the levels of myeloperoxidase (MPO) and interleukin (IL)-6 significantly decreased in DOX-treated adult animals. In infants, a significant increase in cardiac protein carbonylation and in the levels of nuclear factor erythroid-2 related factor 2 (Nrf2) was observed. In both groups, no differences were found in the levels of tumor necrosis factor (TNF-α), IL-1β, p38 mitogen-activated protein kinase (p38 MAPK) or NF-κB p52 subunit. In conclusion, using a clinically relevant dose of DOX, our study demonstrated that cardiac effects are associated not only with the intensity of the inflammatory response but also with redox response. Adult mice seemed to be more prone to DOX-induced cardiotoxicity by mechanisms related to inflammation, while infant mice seem to be protected from the damage caused by DOX, possibly by activating such antioxidant defenses as Nrf2.

Evaluation of the Preventive Effects of Carvedilol on Trastuzumab-Induced Cardiotoxicity in Early-Stage and Locally Advanced HER2-Positive Breast Cancer Patients

Background: Trastuzumab is an efficient monoclonal antibody used in the treatment of Her2-positive breast cancer. Despite its prominent effect on Her2-positive patients’ disease-free Survival. Trastuzumab-induced cardiotoxicity is still one of the main challenges. Angiotensin-converting enzyme inhibitors (ACE inhibitors) are one of the most potent agents used in heart failure, which also showed confirmed cardioprotective effects against anthracycline and doxorubicin. We aimed to assess the cardioprotective effects of Carvedilol in a randomized clinical trial study.

Materials and Methods: sixty non-metastatic Her-2 positive patients (30 cases; 30 controls) were entered into the study via a simple randomization method.Carvedilol was administered for the patients with the starting dose of 3.125 mg twice a day and started 7 days before trastuzumab administration. The dose has been increased in a three-week period to reach 12.5 mg twice a day and continued until the end of therapy. All the patients underwent an echocardiography after receiving Adriamycin and Cyclophosphamide in order to measure basal Ejection Fraction (EF) and Pulmonary Artery Pressure (PAP). Each patient underwent a follow-up echocardiography in 3,6,9 and 12 months after initiation of the treatment. Finally, all the patients went through the last episode of echocardiography 1 month after the end of treatment. All the Measured PAP and EF has been recorded and analyzed

Results: EF and PAP changes for both groups had no significant changes during the course of treatment with Trastuzmab (p-value = 0.628 and p-value = 0.723, respectively). Seven patients in the intervention group and 2 patients in the control group presented with EF decrease. Also, 8 patients in the intervention and 9 patients in the control groups showed PAP increase.

Conclusion: According to our results, in patients with HER2-positive breast cancer treated with trastuzumab, Carvedilol showed no significant protective effect on trastuzumab-induced cardiotoxicity.

Photobiomodulation therapy preconditioning modifies nitric oxide pathway and oxidative stress in human-induced pluripotent stem cell-derived ventricular cardiomyocytes treated with doxorubicin

Doxorubicin (DOX) is an anthracycline antibiotic that exhibits high heart toxicity. Human-induced pluripotent stem cell-derived ventricular cardiomyocytes (hiPSC-vCMs) are important in vitro models for testing drug cardiotoxicity. Photobiomodulation therapy (PBMT) is a non-invasive therapy that stimulates cells growth and self-repair using light irradiation. This study aimed to investigate the in vitro effects of PBMT preconditioning on cardiotoxicity induced by DOX. HiPSC-vCMs were treated with PBMT for 500 s, followed by the addition of 2 μM DOX. LED irradiation preconditioning parameters were at 660 nm with an irradiance of 10 mW/cm², performing 5 J/cm², followed by 24-h DOX exposure (2 μM). Human iPSC-vCMs treated with 2 μM DOX or irradiated with PBMT composed the second and third groups, respectively. The control group did neither receive PBMT preconditioning nor DOX and was irradiated with a white standard lamp. Cells from all groups were collected to perform mRNA and miRNA expressions quantification. PBMT, when applied before the DOX challenge, restored the viability of hiPSC-vCMs and reduced ROS levels. Although downregulated by DOX, myocardial UCP2 mRNA expression presented marked upregulation after PBMT preconditioning. Expression of eNOS and UCP2 mRNA and NO production were decreased after DOX exposure, and PBMT preconditioning before the DOX challenge reversed these changes. Moreover, our data indicated that PBMT preconditioning lowered the miR-24 expression. Our data suggested that PBMT preconditioning ameliorated in vitro DOX-induced cardiotoxicity on transcription level, restoring NO levels and reducing oxidative stress.

Anthracycline-induced cardiotoxicity: mechanisms of action, incidence, risk factors, prevention, and treatment

Anthracycline is a mainstay in treatment of many cancers including lymphoma and breast cancer among many others. However, anthracycline treatment can be cardiotoxic. Although anthracycline-induced cardiotoxicity is dose dependent, it can also occur early at the onset of treatment and even up to several years following completion of treatment. This review article focuses on the understanding of mechanisms of anthracycline-induced cardiotoxicity, the treatments, and recommended follow-up and preventive approaches.

The mitochondrial permeability transition pore: an evolving concept critical for cell life and death

In this review, we summarize current knowledge of perhaps one of the most intriguing phenomena in cell biology: the mitochondrial permeability transition pore (mPTP). This phenomenon, which was initially observed as a sudden loss of inner mitochondrial membrane impermeability caused by excessive calcium, has been studied for almost 50 years, and still no definitive answer has been provided regarding its mechanisms. From its initial consideration as an in vitro artifact to the current notion that the mPTP is a phenomenon with physiological and pathological implications, a long road has been travelled. We here summarize the role of mitochondria in cytosolic calcium control and the evolving concepts regarding the mitochondrial permeability transition (mPT) and the mPTP. We show how the evolving mPTP models and mechanisms, which involve many proposed mitochondrial protein components, have arisen from methodological advances and more complex biological models. We describe how scientific progress and methodological advances have allowed milestone discoveries on mPTP regulation and composition and its recognition as a valid target for drug development and a critical component of mitochondrial biology.

Resveratrol significantly improves cell survival in comparison to dexrazoxane and carvedilol in a h9c2 model of doxorubicin induced cardiotoxicity

Cancer is one of the leading causes of deaths worldwide with 18.1 million deaths per year. Although there have been significant advances in anti-cancer therapies, they can often result in side effects with cardiovascular complications being the most severe. Dexrazoxane is the only currently approved treatment for prevention of anthracycline induced cardiotoxicity but there are concerns about its use due to the development of secondary malignancies and myelodysplastic syndrome. Additionally, it is only recommended in patients who are due to receive a total cumulative dose of 300 mg/m² of doxorubicin or 540 mg/m² of epirubicin. Thus, there exists an urgent need to develop new therapeutic strategies to counteract anthracycline induced cardiotoxicity. The h9c2 cardiomyoblast was investigated for its differentiation capacity and used to screen and compare promising prophylactics for doxorubicin induced cardiotoxicity. The half maximal inhibitory concentration of doxorubicin was determined in differentiated h9c2 cells after 24 h of exposure, to establish a model for drug screening. Cells were treated with dexrazoxane, resveratrol, and carvedilol either 3 h or 24 h prior to doxorubicin treatment. The ability of these cardioprotectants to prevent cardiotoxicity was analysed using the cck-8 cell viability assay and the dichlorofluorescin diacetate (DCFDA) reactive oxygen species (ROS) assay. There was no significant increase in survival in treatment groups after 3 h, however, at 24 h, resveratrol significantly improved survival compared to all other groups (p < 0.05). Additionally, dexrazoxane and resveratrol significantly decreased ROS formation at 3 h (p < 0.05) and all groups significantly decreased ROS production at 24 h (p < 0.001). This work is the first comparison of these cardioprotectants and suggests that resveratrol may be a more effective treatment in the prevention of anthracycline induced cardiotoxicity, compared to dexrazoxane and carvedilol. However, further work will be needed in order to decipher the exact mechanism and potential of this drug in the clinic.

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

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

HSP27 role in cardioprotection by modulating chemotherapeutic doxorubicin-induced cell death

The common phenomenon expected from any anti-cancer drug in use is to kill the cancer cells without any side effects to non-malignant cells. Doxorubicin is an anthracycline derivative anti-cancer drug active over different types of cancers with anti-cancer activity but attributed to unintended cytotoxicity and genotoxicity triggering mitogenic signals inducing apoptosis. Administration of doxorubicin tends to both acute and chronic toxicity resulting in cardiomyopathy (left ventricular dysfunction) and congestive heart failure (CHF). Cardiotoxicity is prevented through administration of different cardioprotectants along with the drug. This review elaborates on mechanism of drug-mediated cardiotoxicity and attenuation principle by different cardioprotectants, with a focus on Hsp27 as cardioprotectant by prevention of drug-induced oxidative stress, cell survival pathways with suppression of intrinsic cell death. In conclusion, Hsp27 may offer an exciting/alternating cardioprotectant, with a wider study being need of the hour, specifically on primary cell line and animal models in conforming its cardioprotectant behaviour.

Evaluation of cardioprotective effects of carvedilol in dogs receiving doxorubicin chemotherapy: A prospective, randomized, double-blind, placebo controlled pilot study

The aim of this pilot study was to evaluate the cardioprotective effects of carvedilol in dogs receiving doxorubicin chemotherapy and provide suggestions to future studies based on results and limitations of our study. Thirteen dogs were randomized into two experimental groups: 6 dogs in carvedilol group and 7 dogs in placebo group. In carvedilol group, 0.39 mg/kg ± 0.04 twice-daily oral carvedilol was started on the day of the first doxorubicin treatment and continued throughout the chemotherapy protocol until the final cardiological evaluation. Cardiological evaluations were performed before the first doxorubicin administration and then 10 to 15 days after each subsequent dose. Troponin I and oxidative stress tests were performed with serum collected from dogs at the initial and final cardiological evaluation. Carvedilol produced some echocardiographic and electrocardiographic changes (reduced E velocity and E/IVRT ratio, as well reduced heart rate and increased PR and QT interval) due to its beta-block effect. In placebo group Doppler study showed a significant increase in mitral flow deceleration time (EDT), as well increased amplitude of the S wave in the right, and R wave in the left, precordial chest leads. There were significant difference in the EDT, E/IVRT and A' velocity, as well heart rate, PR interval and R wave in V4/CV6LU precordial chest lead between groups. In conclusion, some indexes of diastolic function and in precordial chest leads were less affected by doxorubicin in carvedilol than in control group. This suggests that carvedilol may have a beneficial effect in canine cancer patients receiving doxorubicin.

The possible role of the seaweed Ulva fasciata on ameliorating hyperthyroidism-associated heart inflammations in a rat model

Cardiovascular diseases are key complications primarily associated with hyperthyroidism disorders. The present study sought to ameliorate hyperthyroidism-mediated cardiovascular inflammations and related oxidative stress paradigms in experimental rats using the broadly distributed green seaweed Ulva fasciata. Forty-eight adult male albino rats were recruited and randomly classified into six groups. Hyperthyroidism was stimulated using L-thyroxine sodium at a dose of 100 μg/kg i.p. for 3 weeks daily. Further, 200 mg/kg b.wt. concentration of the U. fasciata methanolic (U. fasciata-MeOH) extract was the recommended dose and administrated orally to the hyperthyroid rats. The standard commercial drug "propranolol hydrochloride" was also tested at a dose of 10 mg/kg i.p. to compare the findings obtained from the seaweed extract. A combined treatment with the U. fasciata-MeOH extract and propranolol hydrochloride was also assessed. Our results implied that the treatment of hyperthyroid rats with the U. fasciata-MeOH extract significantly reduced serum levels of the thyroid hormones T3 and T4, proinflammatory cytokines (TNF-α, MPO, and CRP), triglycerides and total cholesterol, as well as the cardiac biomarkers CK-MB, LDH, and troponin to thresholds close to those of the standard drug. In addition, levels of high-density lipoprotein cholesterol (HDL-C) and interleukin 10 (IL-10) were significantly upregulated. Hyperthyroid rats only treated with propranolol hydrochloride, or with a combination of the drug and the seaweed extract, conferred the same observations. Histopathological architecture boosted our interesting findings where the myocardium tissues in hyperthyroid rats, administrated the U. fasciata-MeOH extract or/and propranolol hydrochloride, exhibited more or less a normal structure as the control, reflecting the potential cardiovascular recovery exerted by this seaweed extract. In vitro DPPH, ABTS, and FRAP antioxidant assays of the U. fasciata-MeOH extract showed an outstanding ROS-scavenging potential. HPLC analysis of the U. fasciata-MeOH extract unraveled an inestimable valuable array of phenolics (mainly p-coumaric, gallic, ferulic, chlorogenic, and syringic acids) and flavonoids (hesperidin, kaempferol, catechin, quercetin, and rutin). Conclusively, the seaweed U. fasciata is a profitable source of antioxidant polyphenolics characterized by having a pharmaceutical potential against hyperthyroidism-linked cardiovascular inflammations and oxidative stress patterns due to their substantial free radical quenching properties, and also via regulating the signalling pathways of the proinflammatory, lipid profile, and cardiac biomarkers.

Caloric restriction reduces sympathetic activity similar to beta-blockers but conveys additional mitochondrio-protective effects in aged myocardium

Increased activation of sympathetic nervous system contributes to congestive heart failure (CHF) progression, and inhibition of sympathetic overactivation by beta-blockers is successful in CHF patients. Similarly, caloric restriction (CR) reduces sympathetic activity but mediates additional effects. Here, we compared the cardiac effects of CR (− 40% kcal, 3 months) with beta-blocker therapy (BB), diuretic medication (DF) or control diet in 18-months-old Wistar rats. We continuously recorded blood pressure, heart rate, body temperature and activity with telemetric devices and analysed cardiac function, activated signalling cascades and markers of apoptosis and mitochondrial biogenesis. During our study, left ventricular (LV) systolic function improved markedly (CR), mildly (BB) or even deteriorated (DF; control). Diastolic function was preserved by CR and BB but impaired by DF. CR reduced blood pressure identical to DF and BB and heart rate identical to BB. Plasma noradrenaline was decreased by CR and BB but increased by DF. Only CR reduced LV oxidative damage and apoptosis, induced AMPK and Akt phosphorylation and increased mitochondrial biogenesis. Thus, additive to the reduction of sympathetic activity, CR achieves protective effects on mitochondria and improves LV function and ROS damage in aged hearts. CR mechanisms may provide additional therapeutic targets compared to traditional CHF therapy.

Ginger extract attenuates labetalol induced apoptosis, DNA damage, histological and ultrastructural changes in the heart of rat fetuses

Labetalol is a medication used to treat maternal hypertension during pregnancy. However, it is often associated with many side effects. Recently, several studies have been focused on the protective effect of medicinal plant extracts, such as ginger, against drugs inducing toxicity. Therefore, it has been hypothesized that ginger aqueous extraction can ameliorate labetalol-induced histological, ultrastructural changes, DNA damage, and apoptosis in fetal heart tissue. To achieve the aim of this study, sixty pregnant female albino rats were divided into 4 groups (15 each). Group I (Control). Group II received ginger (200 mg/kg). Group III received labetalol (300 mg/kg). Group IV received labetalol first followed by ginger. All groups were orally injected daily during the organogenesis phase of gestation i.e., from the 6th to the 15th day, and sacrificed at the 20th day of gestation. Results showed that labetalol-induced marked histological and ultrastructural alterations. Also, there was severe DNA damage and an increase in the apoptotic rates determined by Annexin-V/PI dual staining assay. Injection of the ginger aqueous extract caused evident improvement in cardiac tissue, DNA damage, and apoptotic rates. In conclusion, the results suggest that ginger extract could be a potential candidate agent for reducing labetalol-induced cardiotoxicity in the fetal heart of albino rats.

Galuminox: Preclinical validation of a novel PET tracer for non-invasive imaging of oxidative stress in vivo

Overproduction of reactive oxygen species (ROS) is a well-established indicator of ongoing tissue inflammation. However, there is a scarcity of molecular imaging probes capable of providing noninvasive sensitive detection of ROS for allowing longitudinal studies of disease pathology and/or monitoring therapeutic efficacy of ROS scavengers. Herein, we report synthesis and chemical characterization of a novel metalloprobe, Galuminox, a moderately fluorescent agent that detects superoxide and hydrogen peroxide generation. Using live-cell fluorescence imaging analysis, Galuminox demonstrates ability to detect superoxide and monitor effects of ROS-attenuating agents, such as Carvedilol, Dexrazoxane, and mitoTempo in lung epithelial A549 cells. Furthermore, LPS stimulation of A549 cells that either express the mitochondria targeted fluorescent protein Keima or are stained with MitoSOX, a mitochondria-specific superoxide probe, indicates preferential co-localization of Galuminox with mitochondria producing elevated amounts of superoxide. Dynamic PET/CT scans 45 min post tail-vein administration of ⁶⁸Ga-Galuminox show 4-fold higher uptake and stable retention in lungs of LPS treated mice compared to their saline-only treated counterparts. Post preclinical PET imaging, quantitative biodistribution studies also correlate with 4-fold higher retention of the radiotracer in lungs of LPS treated mice compared with their saline-only treated control counterparts. Consistent with these observations, lung cells isolated from LPS-treated mice demonstrated elevated ROS production deploying CellROX, the ROS probe. Finally, Galuminox uptake correlates with histological and physiological evidence of acute lung injury as evident by polynuclear infiltration, thickening of the alveolar epithelial membranes and increased bronchioalveolar lavage protein content. Taken collectively, these data indicate that ⁶⁸Ga-Galuminox tracer uptake is a measure of ROS activity in acutely injured lungs and suggests its potential utility in monitoring oxidative stress in other diseases.

A Mitochondrial Approach to Cardiovascular Risk and Disease

BACKGROUND

Cardiovascular diseases (CVDs) are a leading risk factor for mortality worldwide and the number of CVDs victims is predicted to rise through 2030. While several external parameters (genetic, behavioral, environmental and physiological) contribute to cardiovascular morbidity and mortality; intrinsic metabolic and functional determinants such as insulin resistance, hyperglycemia, inflammation, high blood pressure and dyslipidemia are considered to be dominant factors.

METHODS

Pubmed searches were performed using different keywords related with mitochondria and cardiovascular disease and risk. In vitro, animal and human results were extracted from the hits obtained.

RESULTS

High cardiac energy demand is sustained by mitochondrial ATP production, and abnormal mitochondrial function has been associated with several lifestyle- and aging-related pathologies in the developed world such as diabetes, non-alcoholic fatty liver disease (NAFLD) and kidney diseases, that in turn can lead to cardiac injury. In order to delay cardiac mitochondrial dysfunction in the context of cardiovascular risk, regular physical activity has been shown to improve mitochondrial parameters and myocardial tolerance to ischemia-reperfusion (IR). Furthermore, pharmacological interventions can prevent the risk of CVDs. Therapeutic agents that can target mitochondria, decreasing ROS production and improve its function have been intensively researched. One example is the mitochondria-targeted antioxidant MitoQ10, which already showed beneficial effects in hypertensive rat models. Carvedilol or antidiabetic drugs also showed protective effects by preventing cardiac mitochondrial oxidative damage.

CONCLUSION

This review highlights the role of mitochondrial dysfunction in CVDs, also show-casing several approaches that act by improving mitochondrial function in the heart, contributing to decrease some of the risk factors associated with CVDs.

Cytotoxic-induced heart failure among breast cancer patients in Nigeria: A call to prevent today's cancer patients from being tomorrow's cardiac patients

We report three cases of heart failure (HF) associated with the use of cytotoxic drugs such as anthracycline, cyclophosphamide, and 5-fluorouracil in the treatment of breast cancer in Nigerians. The patients had systolic and diastolic HF: HF with reduced ejection fraction and preserved ejection fraction. The prevalence of breast cancer is increasing across Africa, and cytotoxics are some of the most common and best drugs used during management. The cardiotoxicity caused by these drugs limits their use as chemotherapeutic agents. Cytotoxic-induced HF is a preventable and manageable cause of cardiovascular disease (CVD) in Nigeria and Africa. This article discusses the pathophysiology of cytotoxic-induced HF and presents the risk factors that impair cardiovascular function. The importance of proper assessment and the prophylactic and therapeutic measures in the management of cytotoxic-induced HF are emphasized. The peculiar challenges in the management of cytotoxic-induced HF in Nigeria were also discussed. The need for early involvement of cardiologists by oncologists to improve on the chemotherapeutic and cardiovascular outcome in the management of patients with breast cancer was stressed. Perhaps, it is time to birth a new discipline of cardiooncology in Nigeria.

Effects of doxorubicin-induced cardiotoxicity on cardiac mitochondrial dynamics and mitochondrial function: Insights for future interventions

Anthracyclines is an effective chemotherapeutic treatment used for many types of cancer. However, high cumulative dosage of anthracyclines leads to cardiac toxicity and heart failure. Dysregulation of mitochondrial dynamics and function are major pathways driving this toxicity. Several pharmacological and non‐pharmacological interventions aiming to attenuate cardiac toxicity by targeting mitochondrial dynamics and function have shown beneficial effects in cell and animal models. However, in clinical practice, there is currently no standard therapy for the prevention of anthracycline‐induced cardiotoxicity. This review summarizes current reports on the impact of anthracyclines on cardiac mitochondrial dynamics and mitochondrial function and potential interventions targeting these pathways. The roles of mitochondrial dynamics and mitochondrial function in the development of anthracycline‐induced cardiotoxicity should provide insights in devising novel strategies to attenuate the cardiac toxicity induced by anthracyclines.

Early Cardiac Mitochondrial Molecular and Functional Responses to Acute Anthracycline Treatment in Wistar Rats

Doxorubicin (DOX) is an anticancer drug widely used to treat human and nonhuman tumors but the late and persistent cardio-toxicity reduces the therapeutic utility of the drug. The full mechanism(s) of DOX-induced acute, subchronic and delayed toxicity, which has a preponderant mitochondrial component, remains unclear; therefore, it is clinically relevant to identify early markers to identify patients who are predisposed to DOX-related cardiovascular toxicity. To address this, Wistar rats (16 weeks old) were treated with a single DOX dose (20 mg/kg, i.p.); then, mRNA, protein levels and functional analysis of mitochondrial endpoints were assessed 24 h later in the heart, liver, and kidney. Using an exploratory data analysis, we observed cardiac-specific alterations after DOX treatment for mitochondrial complexes III, IV, and preferentially for complex I. Conversely, the same analysis revealed complex II alterations are associated with DOX response in the liver and kidney. Interestingly, H2O2 production by the mitochondrial respiratory chain as well as loss of calcium-loading capacity, markers of subchronic toxicity, were not reliable indicators of acute DOX cardiotoxicity in this animal model. By using sequential principal component analysis and feature correlation analysis, we demonstrated for the first time alterations in sets of transcripts and proteins, but not functional measurements, that might serve as potential early acute markers of cardiac-specific mitochondrial toxicity, contributing to explain the trajectory of DOX cardiac toxicity and to develop novel interventions to minimize DOX cardiac liabilities.

Mitochondrial Determinants of Doxorubicin-Induced Cardiomyopathy

Anthracycline-based chemotherapy can result in the development of a cumulative and progressively developing cardiomyopathy. Doxorubicin is one of the most highly prescribed anthracyclines in the United States due to its broad spectrum of therapeutic efficacy. Interference with different mitochondrial processes is chief among the molecular and cellular determinants of doxorubicin cardiotoxicity, contributing to the development of cardiomyopathy. The present review provides the basis for the involvement of mitochondrial toxicity in the different functional hallmarks of anthracycline toxicity. Our objective is to understand the molecular determinants of a progressive deterioration of functional integrity of mitochondria that establishes a historic record of past drug treatments (mitochondrial memory) and renders the cancer patient susceptible to subsequent regimens of drug therapy. We focus on the involvement of doxorubicin-induced mitochondrial oxidative stress, disruption of mitochondrial oxidative phosphorylation, and permeability transition, contributing to altered metabolic and redox circuits in cardiac cells, ultimately culminating in disturbances of autophagy/mitophagy fluxes and increased apoptosis. We also suggest some possible pharmacological and nonpharmacological interventions that can reduce mitochondrial damage. Understanding the key role of mitochondria in doxorubicin-induced cardiomyopathy is essential to reduce the barriers that so dramatically limit the clinical success of this essential anticancer chemotherapy.

Cardiotoxicity of Anthracyclines

Cardiotoxicity is a feared side effect that may limit the clinical use of anthracyclines. It may indeed affect the quality of life and survival of patients with cancer, regardless of oncological prognosis. This paper provides an overview of anthracycline-induced cardiotoxicity in terms of definition, classification, incidence, risk factors, possible mechanisms, diagnosis, and treatment. We also report effective strategies for preventing cardiotoxicity. In addition, we discuss limiting current approaches, the need for a new classification, and early cardiotoxicity detection and treatment. Probably, anthracycline-induced cardiotoxicity is a continuous phenomenon that starts from myocardial cell injury; it is followed by left ventricular ejection fraction (LVEF) and, if not diagnosed and cured early, progressively leads to symptomatic heart failure. Anthracycline-induced cardiotoxicity can be detected at a preclinical phase. The role of biomarkers, in particular troponins, in identifying subclinical cardiotoxicity and its therapy with angiotensin-converting enzyme inhibitors (mainly enalapril) to prevent LVEF reduction is a recognized and effective strategy. If cardiac dysfunction has already occurred, partial or complete LVEF recovery may still be obtained in case of early detection of cardiotoxicity and prompt heart failure treatment.

Mechanisms of Anthracycline-Induced Cardiotoxicity: Is Mitochondrial Dysfunction the Answer?

Cardiac side effects are a major drawback of anticancer therapies, often requiring the use of low and less effective doses or even discontinuation of the drug. Among all the drugs known to cause severe cardiotoxicity are anthracyclines that, though being the oldest chemotherapeutic drugs, are still a mainstay in the treatment of solid and hematological tumors. The recent expansion of the field of Cardio-Oncology, a branch of cardiology dealing with prevention or treatment of heart complications due to cancer treatment, has greatly improved our knowledge of the molecular mechanisms behind anthracycline-induced cardiotoxicity (AIC). Despite excessive generation of reactive oxygen species was originally believed to be the main cause of AIC, recent evidence points to the involvement of a plethora of different mechanisms that, interestingly, mainly converge on deregulation of mitochondrial function. In this review, we will describe how anthracyclines affect cardiac mitochondria and how these organelles contribute to AIC. Furthermore, we will discuss how drugs specifically targeting mitochondrial dysfunction and/or mitochondria-targeted drugs could be therapeutically exploited to treat AIC.

Antitumoral effects of [6]-gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] in sarcoma 180 cells through cytogenetic mechanisms

BACKGROUND

[6]-Gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] is a phenolic substance reported for several ethnopharmacological usage by virtue of its antioxidant, antiemetic, anti-inflammatory and anticancer properties. This study assessed the antitumoral effects of [6]-Gingerol in primary cells of Sarcoma 180 as well as in peripheral blood lymphocytes of mice.

METHODS

The effect of [6]-Gingerol was assessed by applying cytogenetic biomarkers as indicative of genotoxicity, mutagenicity and apoptosis. Ascitic liquid cells were treated with [6]-Gingerol at concentrations of 21.33, 42.66 and 85.33 μM and subjected to the cytotoxicity assays using Trypan blue test and the comet assay, as well as the cytokinesis-block micronucleus assay. Doxorubicin (6 μM) and hydrogen peroxide (85.33 μM) were used as positive controls.

RESULTS

[6]-Gingerol, especially at concentrations of 42.66 and 85.33 μM, showed notable cytotoxicity in Sarcoma 180 cells by reducing cell viability and cell division rates via induction of apoptosis. Genotoxicity at the concentrations used was punctuated by the increase in the index and frequency of DNA damage in tested groups. [6]-Gingerol, at all concentrations tested, did not induce significant aneugenic and/or clastogenic effects. It did, however, induced other nuclear abnormalities, such as nucleoplasmic bridges, nuclear buds and apoptosis. The genotoxic effects observed in the cotreatment with H₂O₂ (challenge assay) employing neoplastic and healthy cells, indicated that [6]-Gingerol may induce oxidative stress.

CONCLUSIONS

Observations suggest that [6]-Gingerol may be a candidate for pharmaceutical antitumoral formulations due to its cytotoxicity and to mechanisms associated with genetic instability generated by nuclear alterations especially by apoptosis.

Prevention of doxorubicin-induced Cardiotoxicity by pharmacological non-hypoxic myocardial preconditioning based on Docosahexaenoic Acid (DHA) and carvedilol direct antioxidant effects: study protocol for a pilot, randomized, double-blind, controlled trial (CarDHA trial)

Background

Anthracycline-induced cardiotoxicity (AIC), a condition associated with multiple mechanisms of damage, including oxidative stress, has been associated with poor clinical outcomes. Carvedilol, a β-blocker with unique antioxidant properties, emerged as a strategy to prevent AIC, but recent trials question its effectiveness. Some evidence suggests that the antioxidant, not the β-blocker effect, could prevent related cardiotoxicity. However, carvedilol’s antioxidant effects are probably not enough to prevent cardiotoxicity manifestations in certain cases. We hypothesize that breast cancer patients taking carvedilol as well as a non-hypoxic myocardial preconditioning based on docosahexaenoic acid (DHA), an enhancer of cardiac endogenous antioxidant capacity, will develop less subclinical cardiotoxicity manifestations than patients randomized to double placebo.

Methods/design

We designed a pilot, randomized controlled, two-arm clinical trial with 32 patients to evaluate the effects of non-hypoxic cardiac preconditioning (DHA) plus carvedilol on subclinical cardiotoxicity in breast cancer patients undergoing anthracycline treatment. The trial includes four co-primary endpoints: changes in left ventricular ejection fraction (LVEF) determined by cardiac magnetic resonance (CMR); changes in global longitudinal strain (GLS) determined by two-dimensional echocardiography (ECHO); elevation in serum biomarkers (hs-cTnT and NT-ProBNP); and one electrocardiographic variable (QTc interval). Secondary endpoints include other imaging, biomarkers and the occurrence of major adverse cardiac events during follow-up. The enrollment and follow-up for clinical outcomes is ongoing.

Discussion

We expect a group of anthracycline-treated breast cancer patients exposed to carvedilol and non-hypoxic myocardial preconditioning with DHA to show less subclinical cardiotoxicity manifestations than a comparable group exposed to placebo.

Trial registration

ISRCTN registry, ID: ISRCTN69560410. Registered on 8 June 2016.

Role of cardioprotective agents on chemotherapy-induced heart failure: A systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Although previous clinical randomized controlled trials (RCTs) have tested the effect of a variety of cardioprotective agents on cancer therapy-induced cardiotoxicity, the number of included patients was limited, and the results remained controversial. In this study, we aimed to evaluate the preventive or therapeutic effects of cardioprotective agents on heart failure (HF) caused by cardiotoxicity induced by cancer therapy.

METHODS

We included trials of the following cardioprotective drugs: Angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, beta-blockers, aldosterone antagonists and stains. We extracted the relevant information with predefined data extraction forms, and assessed the risk of bias in randomized controlled trials with the Cochrane risk of bias tool. The primary outcome was the left ventricular ejection fraction of patients after chemotherapy. We used the random-effects model to carry out pair-wise meta-analysis, and then carry out the random-effects network meta-analysis within the Bayesian framework.

RESULTS

Twenty-two relevant RCTs, including 1 916 patients (79.6 % women) with a mean age of 48.4 years, were included. Based on the evaluation of all drug species from 20 studies (26 comparisons), the analysis found that 4 therapies, aldosterone antagonists (MD, 12.78 [95 % CI, 2.87-22.69] and MD, 13.75 [95 % CI, 2.21-25.30]), ACEIs (MD, 6.79 [95 % CI, 2.11-11.48] and MD, 7.76 [95 % CI, 2.64-12.88]), statin (MD, 8.35 [95 % CI, 1.11-15.59]), and beta-blockers (MD, 4.00 [95 % CI, 0.87-7.14]), had a higher efficacy than placebo and/or control, suggesting an LVEF protective effect of cardioprotective therapy. In the analysis classified by single drug or drug combination, based on 22 studies (31 comparisons), spironolactone (MD, 12.77 [95 % CI, 1.76-23.79] and MD, 14.62 [95 % CI, 1.70-27.55]), a combination of candesartan and carvedilol (MD, 12.40 [95 % CI, 0.99-23.81]), enalapril (MD, 7.35 [95 % CI, 1.16-13.54] and MD, 9.20 [95 % CI, 2.61-15.79]), and statin (MD, 8.36 [95 % CI, 0.36-16.36]) showed significant benefits in protecting left ventricular (LV) systolic function compared with the placebo and/or control.

CONCLUSION

When classified according to drug type, aldosterone antagonists, ACEIs, statins, and beta-blockers could substantially improve the LV systolic function. In the analysis classified by single drug or drug combination, spironolactone, enalapril, and statin have a significant cardioprotective effect. However, ARBs have no cardioprotective effect and fail to improve the LVEF.

Cancer Therapy-Related Cardiac Dysfunction: An Overview for the Clinician

Cancer therapy-related cardiac dysfunction (CTRCD) is one of the most feared and undesirable side effects of chemotherapy, occurring in approximately 10% of the patients. It can be classified as direct (dose-dependent vs dose-independent) or indirect, either case being potentially permanent or reversible. Risk assessment, recognition, and prevention of CTRCD are crucial.

Advantages of prophylactic versus conventionally scheduled heart failure therapy in an experimental model of doxorubicin-induced cardiomyopathy

BACKGROUND

Chemotherapy-induced left ventricular dysfunction represents a major clinical problem, which is often only recognised at an advanced stage, when supportive therapy is ineffective. Although an early heart failure treatment could positively influence the health status and clinical outcome, there is still no evidence of routine prophylactic cardioprotection for the majority of patients without previous cardiovascular history awaiting potentially cardiotoxic chemotherapy. In this study, we set out to investigate whether a prophylactic cardioprotective therapy relative to a conventionally scheduled heart failure treatment is more effective in preventing cardiotoxicity in a rodent model of doxorubicin (DOX)-induced cardiomyopathy.

METHODS

Male Wistar rats (n = 7-11 per group) were divided into 4 subgroups, namely negative controls receiving intravenous saline (CON), positive controls receiving intravenous DOX (6 cycles; D-CON), and DOX-treated animals receiving either prophylactic (PRE, started 1 week before DOX) or conventionally applied (POST, started 1 month after DOX) combined heart failure therapy of oral bisoprolol, perindopril and eplerenone. Blood pressure, heart rate, body weight and echocardiographic parameters were monitored in vivo, whereas myocardial fibrosis, capillarisation, ultrastructure, myofilament function, apoptosis, oxidative stress and mitochondrial biogenesis were studied in vitro.

RESULTS

The survival rate in the PRE group was significantly improved compared to D-CON (p = 0.0207). DOX increased the heart rate of the animals (p = 0.0193), while the blood pressure (p ≤ 0.0105) and heart rate (p = 0.0029) were significantly reduced in the PRE group compared to D-CON and POST. The ejection fraction remained preserved in the PRE group compared to D-CON or POST (p ≤ 0.0237), while none of the treatments could prevent the DOX-induced increase in the isovolumetric relaxation time. DOX decreased the rate of the actin-myosin cross-bridge cycle, irrespective of any treatment applied (p ≤ 0.0433). The myocardium of the D-CON and POST animals displayed pronounced ultrastructural damage, which was not apparent in the PRE group (p ≤ 0.033). While the DOX-induced apoptotic activity could be reduced in both the PRE and POST groups (p ≤ 0.0433), no treatment was able to prevent fibrotic remodelling or the disturbed mitochondrial biogenesis.

CONCLUSION

For attenuating DOX-induced adverse myocardial effects, prophylactic cardioprotection has many advantages compared to a late-applied treatment.

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.

Insights into Doxorubicin-induced Cardiotoxicity: Molecular Mechanisms, Preventive Strategies, and Early Monitoring

Doxorubicin (DOX) is one of the most effective anticancer drugs to treat various forms of cancers; however, its therapeutic utility is severely limited by its associated cardiotoxicity. Despite the enormous amount of research conducted in this area, the exact molecular mechanisms underlying DOX toxic effects on the heart are still an area that warrants further investigations. In this study, we reviewed literature to gather the best-known molecular pathways related to DOX-induced cardiotoxicity (DIC). They include mechanisms dependent on mitochondrial dysfunction such as DOX influence on the mitochondrial electron transport chain, redox cycling, oxidative stress, calcium dysregulation, and apoptosis pathways. Furthermore, we discuss the existing strategies to prevent and/or alleviate DIC along with various techniques available for therapeutic drug monitoring (TDM) in cancer patients treated with DOX. Finally, we propose a stepwise flowchart for TDM of DOX and present our perspective at curtailing this deleterious side effect of DOX.

Genistein protects against doxorubicin-induced cardiotoxicity through Nrf-2/HO-1 signaling in mice model

Doxorubicin (DOX)-induced cardiomyopathy is a lethal disease. DOX-induced cardiotoxic effects are attributed towards increased redox status and apoptotic signaling. In this study, we show that genistein offers protection against DOX-induced cardio toxicity in the mice model. DOX-mediated increase in serum cardiac troponin and redox markers (ROS, LPO, 4-hydroxynonenal-protein adducts [HNE] levels) was significantly reduced by genistein treatment. Significantly increased TNF-α, IL-6, IL-8 expressions during DOX-induced inflammatory responses were down regulated by genistein treatment. Further, we found that genistein regulated antioxidant response through increased Nrf-2, HO-1, NQO1 protein expressions. In addition, DOX downregulated survival proteins (p-Akt, Bcl-2) with concomitant upregulation in Erk (1/2), Bax and cleaved caspase-3 expressions. The apoptotic activation was significantly downregulated by genistein treatment through suppression of apoptosis. Altogether, these findings show that genistein protects against DOX-induced cardiotoxic effects through activation of Nrf-2/HO-1 signaling.