Electrocardiographic and biochemical evidence for the cardioprotective effect of vitamin E in doxorubicin-induced acute cardiotoxicity in rats

Biodistribution and preclinical safety profile of legubicin: A novel conjugate of doxorubicin and a legumain-cleavable peptide linker

Legubicin is a novel conjugate of doxorubicin and a legumain-cleavable peptide linker. It has been developed to ameliorate the side effects of doxorubicin. Biodistribution in tumor-bearing mice, acute tolerance, and potential systemic toxic effects in Sprague-Dawley rats and beagle dogs of legubicin were assessed. Legubicin exists mainly as a protein complex in plasma after entering the circulation. Compared with conventional doxorubicin at an equal molar dose in mice, we found higher exposure to doxorubicin in tumor (approximately 1.7-fold increase) while lower exposure in normal tissues (an ~3.26-, 3.46-, and 1.29-fold reduction in heart, kidney, and plasma, respectively) in tumor-bearing mice after intravenous injection of legubicin. The acute maximum tolerance dose (MTD) of legubicin was >16 mg/kg doxorubicin equivalent in female rats, 11 mg/kg doxorubicin equivalent in male rats (LD50 of conventional doxorubicin is 10.51 mg/kg), and >8 mg/kg doxorubicin equivalent in dogs (MTD of conventional doxorubicin is 1.5 mg/kg). Four-week repeat-dose toxicity studies of intravenous legubicin were conducted in rats (5, 10, and 25 mg/kg/dose once weekly) and dogs (3/1.5, 10/5, and 20/10 mg/kg/dose once weekly); the dose levels were reduced from the second dose due to intolerable legubicin-associated toxicity at 20 mg/kg. Major organs of toxicity included the gastrointestinal tract, lymphoid and hematopoietic organs, kidney, skin, liver, reproductive organs, and peripheral nerves, which are all associated with doxorubicin. However, cardiotoxicity was only noted at MTD dose levels. Altogether, our results confirm an improved safety profile of legubicin over conventional doxorubicin and support its clinical benefit for treating cancer.

The Essential Strategies to Mitigate Cardiotoxicity Caused by Doxorubicin

The study of mechanisms underlying cardiotoxicity of doxorubicin and the development of strategies to mitigate doxorubicin-induced cardiotoxicity are the most relevant issues of modern cardio-oncology. This is due to the high prevalence of cancer in the population and the need for frequent use of highly effective chemotherapeutic agents, in particular anthracyclines, for optimal management of cancer patients. However, while being a potent agent to counteract cancer, doxorubicin also affects the cardiovascular systems of patients undergoing chemotherapy in a significant and unfavorable fashion. Consecutively reviewed in this article are risk factors and mechanisms of doxorubicin cardiotoxicity, and the essential strategies to mitigate cardiotoxic effects of doxorubicin treatment in cancer patients are discussed.

α-tocopherol as a selective modulator of toxicogenic damage induced by antineoplastic agents cyclophosphamide and doxorubicin

The aim of this study was to determine the oxidative/antioxidative effects, modulatory and selective potential of α-tocopherol (vitamin E) on antineoplastic drug-induced toxicogenetic damage. The toxicity, cytotoxicity and genotoxicity induced by antineoplastic agents cyclophosphamide (CPA) and doxorubicin (DOX) was examined utilizing as models Saccharomyces cerevisiae, Allium cepa, Artemia salina and human peripheral blood mononuclear cells (PBMCs) in the presence of α-tocopherol. For these tests, concentrations of α- tocopherol 100 IU/ml (67mg/ml), CPA 20 µg/ml, DOX 2 µg/ml were used. The selectivity of α-tocopherol was assessed by the MTT test using human mammary gland non-tumor (MCF10A) and tumor (MCF-7) cell lines. Data showed cytoplasmic and mitochondrial oxidative damage induced by CPA or DOX was significantly diminished by α-tocopherol in S. cerevisiae. In addition, the toxic effects on A. salina and cytotoxic and mutagenic effects on A. cepa were significantly reduced by α-tocopherol. In PBMCs, α-tocopherol alone did not markedly affect these cells, and when treated in conjunction with CPA or DOX, α-tocopherol reduced the toxicogenetic effects noted after antineoplastic drug administration as evidenced by decreased chromosomal alterations and lowered cell death rate. In human mammary gland non-tumor and tumor cell lines, α-tocopherol produced selective cytotoxicity with 2-fold higher effect in tumor cells. Evidence indicates that vitamin E (1) produced anti-cytotoxic and anti-mutagenic effects against CPA and DOX (2) increased higher selectivity toward tumor cells, and (3) presented chemoprotective activity in PBMCs.

The Role of Nutrition in Primary and Secondary Prevention of Cardiovascular Damage in Childhood Cancer Survivors

Innovative therapeutic strategies in childhood cancer led to a significant reduction in cancer-related mortality. Cancer survivors are a growing fragile population, at risk of long-term side effects of cancer treatments, thus requiring customized clinical attention. Antineoplastic drugs have a wide toxicity profile that can limit their clinical usage and spoil patients’ life, even years after the end of treatment. The cardiovascular system is a well-known target of antineoplastic treatments, including anthracyclines, chest radiotherapy and new molecules, such as tyrosine kinase inhibitors. We investigated nutritional changes in children with cancer from the diagnosis to the end of treatment and dietary habits in cancer survivors. At diagnosis, children with cancer may present variable degrees of malnutrition, potentially affecting drug tolerability and prognosis. During cancer treatment, the usage of corticosteroids can lead to rapid weight gain, exposing children to overweight and obesity. Moreover, dietary habits and lifestyle often dramatically change in cancer survivors, who acquire sedentary behavior and weak adherence to dietary guidelines. Furthermore, we speculated on the role of nutrition in the primary prevention of cardiac damage, investigating the potential cardioprotective role of diet-derived compounds with antioxidative properties. Finally, we summarized practical advice to improve the dietary habits of cancer survivors and their families.

Trimetazidine improved adriamycin-induced cardiomyopathy by downregulating TNF-α, BAX, and VEGF immunoexpression via an antioxidant mechanism

Few studies have reported a prophylactic effect of the anti-ischemic trimetazidine (TRI) against cardiac toxicity caused by adriamycin (ADR). However, the mechanism of action of TRI remained incomplete. The cardioprotective mechanism(s) of TRI against ADR-induced cardiotoxicity was investigated in this study. Cardiotoxicity was induced in three groups of Wistar rats by injecting a single dose of ADR (10 mg/kg, i.p.). TRI was administered in two doses regimen, low (L) (2.5 mg/kg, i.p.) and high (H) (10 mg/kg, i.p.). The results of the study showed that both TRI L and H doses improved cardiac enzymes and pathology, while only the TRI H dose improved the electrocardiogram. Both TRI L and H doses decreased malondialdehyde and increased reduced glutathione and superoxide dismutase. Only TRI H dose increased glutathione peroxidase and catalase. Both TRI L and H doses decreased interleukin-1 beta and tumor necrosis factor-alpha (TNF-α). Both TRI L and H doses downregulated TNF-α, BAX, and vascular endothelial growth factor cardiac protein expression. The data obtained in this study provided evidence that TRI opposed ADR-induced cardiotoxicity. The mechanism could be due to improved antioxidant levels as well as inhibition of inflammation and programmed cell death.

Alamandine significantly reduces doxorubicin-induced cardiotoxicity in rats

Doxorubicin (DOX) is an anthracycline antibiotic. Despite its unwanted side effects, it has been successfully used in tumor therapy. Given that oxidative stress and inflammatory factors are essential to cardiotoxicity caused by DOX, we assumed that alamandine, which enhances endogenous antioxidants and has anti-inflammatory effects, may prevent DOX-induced cardiotoxicity. Rats received DOX (3.75 mg/kg) i.p on days 14, 21, 28, and 35 (total cumulative dose = 15 mg/kg) and alamandine (50 μg/kg/day) via mini-osmotic pumps for 42 days. At the end of the 42-day period, we evaluated hemodynamic parameters, electrocardiogram, cardiac troponin I (cTnI), superoxidase dismutase (SOD), total antioxidant capacity (TAC), malondialdehyde (MDA), inflammatory cytokines (tumor necrosis factor-α (TNF-α), IL-1β, NF-κB), apoptosis markers (caspase 3), and histopathology of haemotoxylin- and eosin-stained cardiac muscle fibers were evaluated. DOX significantly increased QT, corrected QT (QTc), and RR intervals. Alamandine co-therapy prevented ECG changes. Alamandine administration restored DOX-induced disruptions in the cardiac muscle architecture and vascular congestion. Alamandine co-therapy also alleviated other effects of DOX, including cardiac contractility, decreased systolic and diastolic blood pressure, and increased left ventricular end-diastolic pressure. Moreover, alamandine co-therapy substantially decreased the elevation of oxidative stress markers, inflammatory cytokines, and caspase 3 in DOX-treated rats. The results suggest that alamandine reduced DOX-induced cardiotoxicity via antioxidant, anti-inflammatory, and anti-apoptotic activities.

An update on the mechanisms related to cell death and toxicity of doxorubicin and the protective role of nutrients

Doxorubicin (DOX), is a very effective chemotherapeutic agent against cancer whose clinical use is limited by toxicity. Different strategies have been proposed to attenuate toxicity, including combined therapy with bioactive compounds. This review update mechanisms of action and toxicity of doxorubicin and the role of nutrients like vitamins (A, C, E), minerals (selenium) and n-3 polyunsaturated fatty acids. Protective activities against DOX toxicity in liver, kidney, skin, bone marrow, testicles or brain have been reported, but these have not been evaluated for all of the reviewed nutrients. In most cases oxidation-related effects were present either, by reducing ROS levels and/or increasing antioxidant defenses. Antiapoptotic and anti-inflammatory mechanisms are also commonly reported. In some cases, interferences with autophagy and calcium homeostasis also have shown to be affected. Notwithstanding, there is a wide variety in duration and doses of treatment tested for both, compounds and DOX, which make difficult to compare the results of the studies. In spite of the reduction of DOX cardiotoxicity in health models, DOX anti-cancer activity in cancer cell lines or xenograft models usually did not result compromised when this has been evaluated. Importantly, clinical studies are needed to confirm all the observed effects.

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.

The protective activity of nanomicelle curcumin in bisphenol A-induced cardiotoxicity following subacute exposure in rats

Bisphenol A (BPA), an estrogenic compound, is used in manufacture of polycarbonate plastics and epoxy resins. Curcumin, the active ingredient of turmeric, is a potent protective compound against cardiac diseases. In this study the protective effect of nanomicelle curcumin on BPA-induced subchronic cardiotoxicity in rats was evaluated. Rats were divided into 6 groups including control, nanomicelle curcumin (50 mg/kg, gavage), BPA (50 mg/kg, gavage), nanomicelle curcumin (10, 25, and 50 mg/kg) plus BPA. The treatments were continued for 4 weeks. Results revealed that BPA significantly induced histophatological injuries including focal lymphatic inflammation, nuclear degenerative changes and cytoplasmic vacuolation, increased body weight, systolic and diastolic blood pressures, malondialdehyde and Creatine phosphokinase-MB level and decreased glutathione content in comparison with control group. In addition, in electrocardiographic graph, RR, QT, and PQ intervals were increased by BPA. Western blot analysis showed that BPA up-regulated phosphorylated p38 (p38-mitogen-activated protein kinase) and JNK (c-jun NH2 terminal kinases), while down-regulated phosphorylated AKT (Protein Kinase B) and ERK1/2 (extracellular signal-regulated protein kinases 1 and 2). However, nanomicelle curcumin (50 mg/kg) significantly improved these toxic effects of BPA in rat heart tissue. The results provide evidence that nanomicelle curcumin showed preventive effects on subchronic exposure to BPA induced toxicity in the heart tissue in rats.

A pH-sensitive prodrug strategy to co-deliver DOX and TOS in TPGS nanomicelles for tumor therapy

This work has presented a novel strategy for designing pH-sensitive TOS-H-DOX prodrug-loaded TPGS nanomicelles for co-delivery TOS and DOX to enhance tumor therapy and reduce the toxic side effects. DOX was covalently conjugated to the vitamin E succinate through hydrazone bond to produce an pH-sensitive prodrug TOS-H-DOX (amido bond as a control, TOS-A-DOX), which was responsive to the acidic environment in tumor cells, and the prodrugs were subsequently encapsulated in the core of TPGS nanomicelles via hydrophobic effects with a significant drug loading capacity. The pH-sensitive prodrug nanomicelles TOS-H-DOX/TPGS exhibited potent release of DOX in acidic media relative to the pH-insensitive prodrug nanomicelles TOS-A-DOX/TPGS, and further studies of their intracellular uptake and intracellular localization demonstrated that TOS-H-DOX/TPGS nanomicelles can be effectively taken up by cells and drugs can be released. In vitro results confirmed that TOS-H-DOX/TPGS nanomicelles exhibited significant antitumor cell proliferation activity compared to TOS-A-DOX/TPGS and free DOX, TPGS. Furthermore, in vivo studies further confirmed an excellent synergistic antitumor efficacy in MCF-7 tumor-bearing nude mice model. More importantly, the H&E staining of the heart, liver, kidney tissue sections of experimental nude mice showed that TOS-H-DOX/TPGS nanomicelles can reduce damage to them.

Effect of Crocus sativus L. stigma (saffron) against subacute effect of diazinon: histopathological, hematological, biochemical and genotoxicity evaluations in rats

Objective

In this study, the effects of saffron stigma against subacute diazinon (DZN) toxicity on enzymes levels, biochemical, hematological, histopathological and genotoxicity indices were studied in rats.

Methods

Vitamin E (200 IU/kg) and the aqueous extract of saffron (50, 100 and 200 mg/kg) were injected intraperitoneally three times per week alone or with DZN (20 mg/kg/day, orally) for 4 weeks. The hematological and biochemical parameters were evaluated at the end of 4 weeks.

Results

Reticulocytes counts, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatine phosphokinase, CPK-MB, gama glutamyl transferase (GGT), uric acid and micronucleus indices were increased significantly but total protein and RBC cholinesterase activity were decreased in the DZN-treated group. Saffron prevented the effect of DZN on GGT (50 mg/kg), LDH, CPK and CPK-MB (100 and 200 mg/kg) levels. An increased uric acid and reduced protein levels by DZN were prevented by vitamin E and some doses of saffron. A significant reduction was observed in platelets, RBC, hemoglobin and hematocrit indices in the DZN group. Saffron and vitamin E prevented this reduction. Vitamin E and saffron did not reduce the effect of DZN on RBC cholinesterase activity. The extract and vitamin E could not prevent DZN genotoxicity in the micronucleus assay. Other biochemical parameters and pathological evaluation did not show any abnormality in tissues of all groups.

Conclusion

This study shows that vitamin E and saffron reduce DZN induced hematological and biochemical toxicity. However, they do not prevent the genotoxicity induced by DZN.

Antioxidant, lipid lowering, and membrane stabilization effect of sesamol against doxorubicin-induced cardiomyopathy in experimental rats

The present study was designed to evaluate the cardioprotective effect of sesamol against doxorubicin-induced cardiomyopathy in rats. In this study, the cardioprotective effect of sesamol against doxorubicin induced cardiomyopathy in experimental rats was evaluated at the dosage of 50 mg/kg bw. Doxorubicin was administered to rats at a total cumulative dose of 15 mg/kg through intraperitoneal route for 2 weeks in six-divided dose on 8th, 10th, 14th, 16th, 18th, and 21st day. After the last dose administration, the endogenous antioxidants and lipid peroxidation were estimated in heart tissue homogenate. Cardiac biomarkers such as troponin T, LDH, CK, and AST and lipid profiles such as cholesterol, triglycerides, HDL, LDL, and VLDL were estimated in serum. Sesamol has cardioprotective activity through normalization of doxorubicin-induced-altered biochemical parameters. Biochemical study was further supported by histopathological study, which shows that sesamol offered myocardial protection from necrotic damage. From these findings, it has been concluded that the sesamol has significant cardioprotection against doxorubicin induced cardiomyopathy via amelioration of oxidative stress, lipid lowering, and membrane stabilization effect.

Metformin rescues the myocardium from doxorubicin-induced energy starvation and mitochondrial damage in rats

Clinical use of doxorubicin (DOX) is limited by its cardiotoxic side effects. Recent studies established that metformin (MET), an oral antidiabetic drug, possesses an antioxidant activity. However, whether it can protect against DOX-induced energy starvation and mitochondrial damage has not been reported. Our results, in a rat model of DOX-induced cardiotoxicity, show that DOX treatment significantly increased serum levels of LDH and CK-MB, indicators of cardiac injury, and induced expression of hypertrophic gene markers. DOX also caused marked decreases in the cardiac levels of glutathione, CoA-SH and ATP, and mRNA expression of catalase and NQO-1. These biochemical changes were associated with myocardial histopathological and ultrastructural deteriorations, as observed by light and electron microscopy, respectively. Cotreatment with MET (500 mg/kg) eliminated all DOX-induced biochemical, histopathological, and ultrastructural changes. These findings demonstrate that MET successfully prevents DOX-induced cardiotoxicity in vivo by inhibiting DOX-induced oxidative stress, energy starvation, and depletion of intramitochondrial CoA-SH.

Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress

SIGNIFICANCE

Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity.

RECENT ADVANCES

Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction.

CRITICAL ISSUES

These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress.

FUTURE DIRECTIONS

Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.

Protective effect of bilberry (Vaccinium myrtillus) against doxorubicin-induced oxidative cardiotoxicity in rats

BACKGROUND

Doxorubicin (DOX) is a commonly used chemotherapeutic agent. It is associated with serious dose-limiting cardiotoxicity, which is at least partly caused by generation of reactive oxygen species (ROS). Supplementations with bilberries were effective in reducing oxidative stress in many tissue injuries due their high content of antioxidants. The present study investigated the potential protective effect of bilberry extract against DOX-induced cardiotoxicity in rats.

MATERIAL/METHODS

Rats were treated orally with a methanolic extract of bilberry for 10 days. DOX was injected intraperitoneally on day 7. Twenty-four hours after the last bilberry administration, rats were subjected to ECG study. Blood was then withdrawn and cardiac tissues were dissected for assessment of oxidative stress and cardiac tissue injury. Cardiac tissues were also subjected to histopathological examination.

RESULTS

Bilberry extract significantly inhibited DOX-provoked reduced glutathione depletion and accumulation of oxidized glutathione, malondialdehyde and protein carbonyls in cardiac tissues. This was accompanied by significant amelioration of reduced cardiac catalase, superoxide dismutase, and glutathione peroxidase activities; and increased cardiac myeloperoxidase activity in response to DOX challenge. Pretreatment with bilberry significantly guarded against DOX-induced increase in serum activities of lactate dehydrogenase, creatine phosphokinase and creatine kinase-MB, as well as the level of troponin I. Bilberry alleviated ECG changes in rats treated with DOX and attenuated its pathological changes.

CONCLUSIONS

Bilberry protects against DOX-induced cardiotoxicity in rats. This can be attributed, at least in part, to its antioxidant activity.

New advances in molecular mechanisms and the prevention of adriamycin toxicity by antioxidant nutrients

Anthracyclines (doxorubicin, daunorubicin, epirubicin, and idarubicin) are currently the most effective group of anti-neoplastic drugs used in clinical practice. Of these, doxorubicin (also called adriamycin) is a key chemotherapeutic agent in cancer treatment, although its use is limited as a consequence of the chronic and acute toxicity associated with this drug. The molecular mechanisms of doxorubicin account for both the anti-cancer and the toxic side effects. Many antioxidants have been assayed, with positive or negative results, to prevent the toxicity of doxorubicin. The present review has two main goals: (1) to report the latest findings regarding the molecular mechanisms of doxorubicin toxicity; (2) to update our understanding of the role of natural antioxidants in preventive therapy against doxorubicin-induced toxicity. This review provides new evidence for the chemoprevention of doxorubicin toxicity, making use of natural antioxidants - in particular vitamin E, vitamin C, coenzyme Q, carotenoids, vitamin A, flavonoids, polyphenol, resveratrol, antioxidant from virgin olive oil and selenium - and offers new insights into the molecular mechanisms of doxorubicin toxicity with respect to DNA damage, free radicals and other parameters.

Protective effect of Lycium barbarum on doxorubicin-induced cardiotoxicity

The objective of this work was to explore the hypothesis that Lycium barbarum (LB) may be protective against doxorubicin (DOX)-induced cardiotoxicity through antioxidant-mediated mechanisms. Male SD rats were treated with distilled water or a water extract of LB (25 mg/kg, p.o.) daily and saline or DOX (5 mg/kg, i.v.) weekly for 3 weeks. Mortality, general condition and body weight were observed during the experiment. DOX-induced cardiotoxicity was assessed by electrocardiograph, heart antioxidant activity, serum levels of creatine kinase (CK) and aspartate aminotransferase (AST) and histopathological change. The DOX group showed higher mortality (38%) and worse physical characterization. Moreover, DOX caused myocardial injury manifested by arrhythmias and conduction abnormalities in ECG (increased QT and ST intervals and ST elevation), a decrease of heart antioxidant activity, an increase of serum CK and AST, as well as myocardial lesions. Pretreatment with LB significantly prevented the loss of myofibrils and improved the heart function of the DOX-treated rats as evidenced from lower mortality (13%), normalization of antioxidative activity and serum AST and CK, as well as improving arrhythmias and conduction abnormalities. These results suggested that LB elicited a typical cardioprotective effect on DOX-related oxidative stress. Furthermore, in vitro cytotoxic study showed the antitumor activity of DOX was not compromised by LB. It is possible that LB could be used as a useful adjunct in combination with DOX chemotherapy.

Effects of dexrazoxane and amifostine on evolution of Doxorubicin cardiomyopathy in vivo

Doxorubicin is one of the most active drugs in oncology, with cardiotoxicity as a serious side effect of its application. The aim of this study was to investigate dexrazoxane and amifostine impact on the evolution of myocardial changes induced by doxorubicin. BalbC female mice were treated with doxorubicin only (10 mg/kg, single intravenous push), or with dexrazoxane (200 mg/kg, intraperitoneal [ip]) or amifostine (200 mg/kg, ip) 60 mins or 30 mins prior to treatment with doxorubicin, respectively. Blood sampling for determination of conventional serum-marker activity was performed 48 hrs later. The grade of histopathology changes was evaluated by light microscopy 1.5 and 3 months after treatments using the Billingham scoring method. Control groups consisted of nontreated mice. After doxorubicin-only treatment, the grade of heart tissue damage was found to increase in the period between 1.5 and 3 months. A similar but less intense progression was also detected in amifostine-pretreated animals, with significant difference among median Billingham scores between the two time points. The pretreatment with dexrazoxane suspended expansion of tissue lesions in time. Changes in serum enzyme activity revealed two correlations: the greater reduction in alpha-hydroxybutyrate dehydrogenase (alpha-HBDH) leakage is associated with a lower percentage of damaged tissue, and the creatine kinase to alpha-HBDH percent of difference ratio being greater than one is correlated with limited spreading of pathological lesions. Our results indicate that the development of doxorubicin-induced heart failure is based on a slow and persistent expansion of pathological process even long after the completion of the treatment. Dexrazoxane has proved to be successful and superior over amifostine against such an evolution of doxorubicin cardiomyopathy.

Angelica sinensis: a novel adjunct to prevent doxorubicin-induced chronic cardiotoxicity

Doxorubicin is an anthracycline antibiotic agent used in the treatment of a variety of solid and haematopoietic tumours, but its use is limited by formation of metabolites that induce acute and chronic cardiac toxicities. Angelica sinensis has been widely used to treat cardiovascular and cerebrovascular diseases in China. In the present study, we used an in vivo mouse model to explore whether A. sinensis could protect against doxorubicin-induced chronic cardiotoxicity. Male ICR mice were treated with distilled water or water extraction of A. sinensis (15 g/kg, orally) daily for 4 weeks, followed by saline or doxorubicin (15 mg/kg, intravenously) treatments weekly. Cardiotoxicity was assessed by electrocardiograph, antioxidant activity in cardiac tissues, serum levels of creatine kinase, aspartate aminotransferase (AST) and histopathological change in cardiac tissues. A cumulative dose of doxorubicin (60 mg/kg) caused animal death and myocardial injury characterized by increased QT interval and decreased heart rate in electrocardiograph, decrease of heart antioxidant activity, increase of serum AST, as well as myocardial lesions. Pre-treatment with A. sinensis significantly reduced mortality and improved heart performance of the doxorubicin-treated mice as evidenced from normalization of antioxidative activity and serum AST, preventing loss of myofibrils as well as improving arrhythmias and conduction abnormalities. Furthermore, the in vitro cytotoxic study showed that A. sinensis did not compromise the antitumour activity of doxorubicin. These results suggested that A. sinensis elicited a typical cardioprotective effect on doxorubicin-related oxidative stress, and could be a novel adjunct in the combination with doxorubicin chemotherapy.