[Preventing the cardiotoxic effects of anthracyclins. From basic concepts to clinical data]

Role of oxidative stress and inflammation-related signaling pathways in doxorubicin-induced cardiomyopathy

Doxorubicin (DOX) is a powerful and commonly used chemotherapeutic drug, used alone or in combination in a variety of cancers, while it has been found to cause serious cardiac side effects in clinical application. More and more researchers are trying to explore the molecular mechanisms of DOX-induced cardiomyopathy (DIC), in which oxidative stress and inflammation are considered to play a significant role. This review summarizes signaling pathways related to oxidative stress and inflammation in DIC and compounds that exert cardioprotective effects by acting on relevant signaling pathways, including the role of Nrf2/Keap1/ARE, Sirt1/p66Shc, Sirt1/PPAR/PGC-1α signaling pathways and NOS, NOX, Fe²⁺ signaling in oxidative stress, as well as the role of NLRP3/caspase-1/GSDMD, HMGB1/TLR4/MAPKs/NF-κB, mTOR/TFEB/NF-κB pathways in DOX-induced inflammation. Hence, we attempt to explain the mechanisms of DIC in terms of oxidative stress and inflammation, and to provide a theoretical basis or new idea for further drug research on reducing DIC. Video Abstract.

Synthesis, characterization, and cytotoxicity of doxorubicin-loaded polycaprolactone nanocapsules as controlled anti-hepatocellular carcinoma drug release system

Background

Free doxorubicin (Dox) is used as a chemotherapeutic agent against hepatocellular carcinoma (HCC), but it results in cardiotoxicty as a major side effect. Hence, a controlled Dox drug delivery system is extremely demanded.

Methods

Dox was loaded into the non-toxic biodegradable polycaprolactone (PCL) nanocapsules using the double emulsion method. Characterization of Dox-PCL nanocapsules was done using transmission electron microscopy and dynamic light scattering. Encapsulation efficiency and drug loading capacity were quantified using UV–visible spectrophotometry. Drug release was investigated in vitro at both normal (7.4) and cancer (4.8) pHs. Cytotoxicity of Dox-PCL nanocapsules against free Dox was evaluated using the MTT test on normal (Vero) and hepatic cancer (HepG2) cell lines.

Results

Spherical nanocapsules (212 ± 2 nm) were succeffully prepared with a zeta potential of (-22.3 ± 2 mv) and a polydisperse index of (0.019 ± 0.01) with a narrow size distribution pattern. The encapsulation efficiency was (73.15 ± 4%) with a drug loading capacity of (16.88 ± 2%). Importantlly, Dox-release from nanocapsules was faster at cancer pH (98%) than at physiological pH (26%). Moreover, although Dox-PCL nanocapsules were less toxic on the normal cell line (GI 50 = 17.99 ± 8.62 µg/ml) than free Dox (GI 50 = 16.53 ± 1.06 µg/ml), the encapsulated Dox showed higher toxic effect on cancer HepG2 cells compared to that caused by the free drug (GI 50 = 2.46 ± 0.49 and 4.22 ± 0.04 µg/ml, respectively).

Conclusion

The constructed Dox-PCL nanocapsules constitute a potentially controlled anti-HCC therapy with minimal systemic exposure.

Graphical Abstract

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.

Early diagnosis of cardiotoxic complications of chemotherapy: the possibility of radiation research methods

Oncological diseases are the main causes of death in the world. Modern treatment of cancer patients contributes to an increase in survival rate due to strong chemotherapeutic drugs, the use of which is accompanied by toxic effects on cardiomyocytes. The main manifestations of cardiotoxicity are left ventricular dysfunction, myocardial ischemia, thromboembolic complications, chronic heart failure. As a result, the risk of cardiovascular mortality may be higher than the risk of death from the tumor process. An important task of oncologists and cardiologists is the early diagnosis of cardiotoxic complications in order to start treatment in time and reduce mortality from cardiovascular pathology in cancer patients.

Les polyphénols de l’extrait n-butanol de Crataegus oxyacantha : évaluation de leur pouvoir antioxydant et protecteur vis-à-vis de la toxicité de la doxorubicine

La doxorubicine (DOX) est un médicament utilisé en chimiothérapie anticancéreuse, son utilisation clinique est limitée en raison de plusieurs effets secondaires qui lui ont été attribués, comme la cardiotoxicité, la néphrotoxicité et l’hépatotoxicité. Dans la présente étude, nous avons étudié l’efficacité protectrice de l’extrait n-butanol d’une plante médicinale de la famille des Rosacées (Crataegus oxyacantha) contre la toxicité cardiaque, rénale et hépatique induite par la DOX chez des rats Wistar femelles en utilisant des paramètres biochimiques. Les rats ont été soumis à un traitement oral pré- et postphylactique concomitant par l’extrait n-butanol (100 mg/kg) contre la toxicité induite par injection intrapéritonéale unique de la DOX (150 mg/kg). La néphrotoxicité et l’hépatotoxicité ont été évaluées en mesurant les taux sériques de la créatinine, de l’urée, de l’aspartateaminotransférase (ASAT), de l’alanine-aminotransférase (ALAT) et du lactate-déshydrogénase (LDH). Le profil lipidique a également été mesuré. Le traitement par l’extrait n-butanol a considérablement diminué les taux des marqueurs sériques de la toxicité provoquée par la DOX. Les résultats biochimiques qui ont montré que la DOX a causé des dommages importants au niveau des tissus étudiés ont été inversés par l’extrait n-butanol. Les résultats suggèrent que l’extrait n-butanol atténue les lésions rénales, cardiaques et hépatiques induites par la DOX. Les tests antioxydants in vitro (piégeage du radical 2,2-diphényl-1-picrylhydrazyl et inhibition de la peroxydation lipidique) de l’extrait n-butanol ont révélé qu’il présente un pouvoir antioxydant très important ; ces activités sont fortement corrélées avec les teneurs en flavonoïdes et en phénols totaux.

Vascular Complications of Cancer Chemotherapy

Development of new anticancer drugs has resulted in improved mortality rates and 5-year survival rates in patients with cancer. However, many of the modern chemotherapies are associated with cardiovascular toxicities that increase cardiovascular risk in cancer patients, including hypertension, thrombosis, heart failure, cardiomyopathy, and arrhythmias. These limitations restrict treatment options and might negatively affect the management of cancer. The cardiotoxic effects of older chemotherapeutic drugs such as alkylating agents, antimetabolites, and anticancer antibiotics have been known for a while. The newer agents, such as the antiangiogenic drugs that inhibit vascular endothelial growth factor signalling are also associated with cardiovascular pathology, especially hypertension, thromboembolism, myocardial infarction, and proteinuria. Exact mechanisms by which vascular endothelial growth factor inhibitors cause these complications are unclear but impaired endothelial function, vascular and renal damage, oxidative stress, and thrombosis might be important. With increasing use of modern chemotherapies and prolonged survival of cancer patients, the incidence of cardiovascular disease in this patient population will continue to increase. Accordingly, careful assessment and management of cardiovascular risk factors in cancer patients by oncologists and cardiologists working together is essential for optimal care so that prolonged cancer survival is not at the expense of increased cardiovascular events.

Role of Drug Metabolism in the Cytotoxicity and Clinical Efficacy of Anthracyclines

Many clinical studies involving anti-tumor agents neglect to consider how these agents are metabolized within the host and whether the creation of specific metabolites alters drug therapeutic properties or toxic side effects. However, this is not the case for the anthracycline class of chemotherapy drugs. This review describes the various enzymes involved in the one electron (semi-quinone) or two electron (hydroxylation) reduction of anthracyclines, or in their reductive deglycosidation into deoxyaglycones. The effects of these reductions on drug antitumor efficacy and toxic side effects are also discussed. Current evidence suggests that the one electron reduction of anthracyclines augments both their tumor toxicity and their toxicity towards the host, in particular their cardiotoxicity. In contrast, the two electron reduction (hydroxylation) of anthracyclines strongly reduces their ability to kill tumor cells, while augmenting cardiotoxicity through their accumulation within cardiomyocytes and their direct effects on excitation/contraction coupling within the myocytes. The reductive deglycosidation of anthracyclines appears to inactivate the drug and only occurs under rare, anaerobic conditions. This knowledge has resulted in the identification of important new approaches to improve the therapeutic index of anthracyclines, in particular by inhibiting their cardiotoxicity. The true utility of these approaches in the management of cancer patients undergoing anthracycline-based chemotherapy remains unclear, although one such agent (the iron chelator dexrazoxane) has recently been approved for clinical use.

Direct and indirect antioxidant properties of α-lipoic acid and therapeutic potential

Diabetes has emerged as a major threat to worldwide health. The exact mechanisms underlying the disease are unknown; however, there is growing evidence that the excess generation of reactive oxygen species (ROS) associated with hyperglycemia, causes oxidative stress in a variety of tissues. In this context, various natural compounds with pleiotropic actions like α-lipoic acid (LA) are of interest, especially in metabolic diseases such as diabetes. LA, either as a dietary supplement or a therapeutic agent, modulates redox potential because of its ability to match the redox status between different subcellular compartments as well as extracellularly. Both the oxidized (disulfide) and reduced (di-thiol: dihydro-lipoic acid, DHLA) forms of LA show antioxidant properties. LA exerts antioxidant effects in biological systems through ROS quenching but also via an action on transition metal chelation. Dietary supplementation with LA has been successfully employed in a variety of in vivo models of disease associated with an imbalance of redox status: diabetes and cardiovascular diseases. The complex and intimate association between increased oxidative stress and increased inflammation in related disorders such as diabetes, makes it difficult to establish the temporal sequence of the relationship.

[Cardiotoxicity of chemotherapies]

The spectrum of chemotherapy's cardiac side effect of chemotherapy has expanded with the new combinations of cytotoxic and targeted therapies over the past 10 years. Moreover, cancer therapy administrated to "new" populations, especially elderly patients or patients with cardiovascular disease and/or coronary artery disease history, has increased considerably. According to the American College of Cardiology and American Heart Association (ACC/AHA), patients receiving chemotherapy can be considered in the A group of heart failure. Many cardiovascular adverse effects appear with cancer therapy and suspend treatment purchase, or leading to an alteration of quality of life, and increasing mortality risks. The most clinically evident cardiotoxicity and best known is the anthracyclines adverse effect. Other cytotoxic are associated with a significant risk of cardiovascular complications include alkylating agents such as 5-fluorouracil and paclitaxel. Cardiovascular adverse effects are associated with the use of targeted therapies such as tyrosine kinase inhibitors: trastuzumab, bevacizumab. At the same time, drugs used to hematological malignancies, as acid all-trans-retinoic acid and arsenic trioxide are cardiotoxics. The most serious cardiac complications of cancer therapies is heart congestive failure, mainly due to the use of anthracyclines, cyclophosphamide and trastuzumab, usually at high doses. Myocardial ischemia is mainly caused by interferon and antimetabolites. Other side effects may occur such as hypotension, hypertension, arrhythmias and conduction disturbances, pericarditis, and thromboembolic complications.

[Short and medium term cardiotoxicity of anthracyclins: a prospective study]

There is evidence that anthracyclins may affect the heart and ventricular function. This cardiac toxicity is frequent and serious. It is the first study in Morocco to investigate the frequency of anthracyclins cardiotoxicity. It has for objective to analyze the cardiotoxicity connected to anthracyclins, these risk factors as well as the echocardiographic parameters, which deteriorate prematurely. We led a forward-looking study between October 2008 and December 2009. With 90 patients followed in the service of oncology-radiotherapy and put under chemotherapy with anthracyclins. We conducted a study of various ultrasound parameters of cardiac function, before with anthracyclins, the third cure of chemotherapy, then in the 6th cure of treatment. Only 70 patients have been assessable. Average age was of 47 years (20-68 years); 91% were female. The cardiac function was preserved in 40% of the cases. Among our patients, 56% developed a decrease moderated in light of the cardiac function and 4% of cases developed a severe cardiotoxicity. The echocardiographic parameter most significant in our series was LVEF, followed by TEI index. We found a cardiotoxicity was strictly correlated with the cumulative dose, anthracyclins type and associated comorbidity. The anthracyclins cardiotoxicity is quite common in our series, which requires more thorough preventive measures including monitoring by echocardiography.

General oxidative stress during doxorubicin-induced cardiotoxicity in rats: absence of cardioprotection and low antioxidant efficiency of alpha-lipoic acid

To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O₂*⁻ (dihydroethidium fluorescence) content in tissue. After two months, body weight was higher in the DOX-AL group than in DOX (+16%), but this was due to ascites. Histological liver alterations were observed in both the DOX and DOX-AL groups. Plasma ROOH concentrations decreased after 10 days of AL treatment, but were greater in both the DOX and DOX-AL groups. After two months, a decrease in the cardiac contractility index (-27% and -29%, respectively) and cardiac hypertrophy were observed in DOX and DOX-AL. These dysfunctions were associated with 1) a reduction in plasma ascorbate levels and an increase in the ascorbyl/ascorbate ratio and 2) an increase MDA and O₂*⁻ content in cardiac tissue. In conclusion, a cumulative dose of 10 mg/kg doxorubicin induced functional alterations in the heart associated with plasma and cardiac oxidative stress. The co-administration of the antioxidant compound AL had no beneficial effects in this situation.