Green tea extracts can counteract the modification of fatty acid composition induced by doxorubicin in cultured cardiomyocytes

Natural Products Counteracting Cardiotoxicity during Cancer Chemotherapy: The Special Case of Doxorubicin, a Comprehensive Review

Cardiotoxicity is a frequent undesirable phenomenon observed during oncological treatment that limits the therapeutic dose of antitumor drugs and thus may decrease the effectiveness of cancer eradication. Almost all antitumor drugs exhibit toxic properties towards cardiac muscle. One of the underlying causes of cardiotoxicity is the stimulation of oxidative stress by chemotherapy. This suggests that an appropriately designed diet or dietary supplements based on edible plants rich in antioxidants could decrease the toxicity of antitumor drugs and diminish the risk of cardiac failure. This comprehensive review compares the cardioprotective efficacy of edible plant extracts and foodborne phytochemicals whose beneficial activity was demonstrated in various models in vivo and in vitro. The studies selected for this review concentrated on a therapy frequently applied in cancer, anthracycline antibiotic-doxorubicin-as the oxidative stress- and cardiotoxicity-inducing agent.

PPARδ, a Potential Therapeutic Target for Heart Disease

The nuclear receptor peroxisome proliferator-activated receptor δ (PPARδ) can transcriptionally regulate target genes. PPARδ exerts essential regulatory functions in the heart, which requires constant energy supply. PPARδ plays a key role in energy metabolism, controlling not only fatty acid (FA) and glucose oxidation, but also redox homeostasis, mitochondrial biogenesis, inflammation, and cardiomyocyte proliferation. PPARδ signaling is impaired in the heart under various pathological conditions, such as pathological cardiac hypertrophy, myocardial ischemia/reperfusion, doxorubicin cardiotoxicity and diabetic cardiomyopathy. PPARδ deficiency in the heart leads to cardiac dysfunction, myocardial lipid accumulation, cardiac hypertrophy/remodeling and heart failure. This article provides an up-today overview of this research area and discusses the role of PPARδ in the heart in light of the complex mechanisms of its transcriptional regulation and its potential as a translatable therapeutic target for the treatment of cardiac disorders.

Evaluation of the phytochemical composition and protective activities of methanolic extracts of Centaurea borysthenica and Centaurea daghestanica (Lipsky) Wagenitz on cardiomyocytes treated with doxorubicin

Centaurea L. is a genus of the family Asteraceae that comprises over 600 taxa. Representatives of the Centaurea genus were used as natural medications for many diseases. Methanolic-aqueous extracts from aerial parts of two Centaurea species: C. borysthenica Gruner and C. daghestanica (Lipsky) Wagenitz were studied for their polyphenolic composition and potential protective effect on cardiomyocytes treated with doxorubicin. Effectiveness of doxorubicin in cancer therapy is limited by a dose-dependent cardiotoxicity. Oxidative stress is a widely recognized mechanism of this phenomenon. One of the most important strategies has been an application of drug together with antioxidant agents. A cardioprotective effect of selected extracts of Centaurea species was suspected in this study. Cell viability, oxidative stress, and mitochondrial membrane potential analyses showed protective activity of the methanolic extract of C. borysthenica and C. daghestanica on rat cardiomyocytes treated with doxorubicin. Although C. borysthenica is more effective as a cardiomyocyte protective agent, in higher concentrations it weakened the drug activity. C. daghestanica extract did not change the doxorubicin efficacy in the evaluated experiment. Interestingly, both tested extracts were cytotoxic for myeloma cells. The detected antioxidant activity of the studied extracts can be used in the prevention of doxorubicin-induced cardiotoxicity.

Protective effects of green tea and its main constituents against natural and chemical toxins: A comprehensive review

Toxins are natural or chemical poisonous substances with severe side effects on health. Humans are generally exposed by widespread toxic contaminations via air, soil, water, food, fruits and vegetables. Determining a critical antidote agent with extensive effects on different toxins is an ultimate goal for all toxicologists. Traditional medicine is currently perceived as a safe and natural approach against toxins. In this regard, we focused on the protective effects of green tea (Camellia sinensis) and its main components such as catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate as a principal source of antioxidants against both natural and chemical toxins. This literate review demonstrates that protective effects of green tea and its constituents were mainly attributed to their anti-oxidative, radical scavenging, chelating, anti-apoptotic properties and modulating inflammatory responses. Although, some studies reveal they have protective effects by increasing toxin metabolism and neutralizing PLA₂, proteases, hyaluronidase and l-amino acid oxidase enzymes.

Cardioprotective Potentials of Plant-Derived Small Molecules against Doxorubicin Associated Cardiotoxicity

Doxorubicin (DOX) is a potent and widely used anthracycline antibiotic for the treatment of several malignancies. Unfortunately, the clinical utility of DOX is often restricted due to the elicitation of organ toxicity. Particularly, the increased risk for the development of dilated cardiomyopathy by DOX among the cancer survivors warrants major attention from the physicians as well as researchers to develop adjuvant agents to neutralize the noxious effects of DOX on the healthy myocardium. Despite these pitfalls, the use of traditional cytotoxic drugs continues to be the mainstay treatment for several types of cancer. Recently, phytochemicals have gained attention for their anticancer, chemopreventive, and cardioprotective activities. The ideal cardioprotective agents should not compromise the clinical efficacy of DOX and should be devoid of cumulative or irreversible toxicity on the naïve tissues. Furthermore, adjuvants possessing synergistic anticancer activity and quelling of chemoresistance would significantly enhance the clinical utility in combating DOX-induced cardiotoxicity. The present review renders an overview of cardioprotective effects of plant-derived small molecules and their purported mechanisms against DOX-induced cardiotoxicity. Phytochemicals serve as the reservoirs of pharmacophore which can be utilized as templates for developing safe and potential novel cardioprotective agents in combating DOX-induced cardiotoxicity.

The differential effects of green tea on dose-dependent doxorubicin toxicity

Background

Doxorubicin (DOX) is an anticancer drug displaying cardiac and hepatic adverse effects mostly dependent on oxidative stress. Green tea (GT) has been reported to play a protective role in diseases resulting from oxidative stress.

Objective

The objective of this study was to evaluate if GT protects against DOX-induced oxidative stress, heart and liver morphological changes, and metabolic disorders.

Methods

Male Wistar rats received intraperitoneal injection of DOX (1.0 or 2.0 mg/kg b.w.) for 7 weeks or concomitantly GT extract soluble in drinking water.

Results

There were multidirectional effects of GT on blood metabolic parameters changed by DOX. Among all tested biochemical parameters, statistically significant protection of GT against DOX-induced changes was revealed in case of blood fatty acid–binding protein, brain natriuretic peptide, and superoxide dismutase.

Conclusion

DOX caused oxidative stress in both organs. It was inhibited by GT in the heart but remained unchanged in the liver. DOX-induced general toxicity and histopathological changes in the heart and in the liver were mitigated by GT at a higher dose of DOX and augmented in rats treated with a lower dose of the drug.

α-Linolenic acid attenuates doxorubicin-induced cardiotoxicity in rats through suppression of oxidative stress and apoptosis

Doxorubicin (DOX), a widely used anti-tumor drug, can give rise to severe cardiotoxicity by oxidative stress and cell apoptosis, which restricts its clinical application. α-Linolenic acid (ALA) has been shown to serve as a potent cardioprotective agent. The aim of this study was to explore the protective effects of ALA on DOX-induced cardiotoxicity and the underlying molecular mechanisms for this cardioprotection in rats. Rats were randomly divided into four groups and administrated with normal saline, ALA (500 µg/kg), DOX (2.5 mg/kg), or ALA (500 µg/kg) plus DOX (2.5 mg/kg) for 17 days. The results showed that DOX treatment significantly increased the heart weight/body weight, liver wet weight (WW)/dry weight (DW), lung WW/DW, serum levels of brain natriuretic peptide, creatine kinase-MB, lactate dehydrogenase, and cardiac troponin I, myocardial necrosis and myocardial malondialdehyde content, and induced the mRNA expression of Nrf2 in the nucleus, cleaved caspase-3, Bax, and superoxide dismutase (SOD). In addition, DOX led to a significant decrease in left ventricular end-diastolic volume, stroke volume, ejection fraction, SOD, glutathione-peroxidase, catalase, as well as the expression of Kelch-like ECH-associated protein 1 (Keap1) in the cytoplasm, phospho-AKT, phospho-ERK, and Bcl-2. Co-treatment with ALA significantly eliminated these changes induced by DOX except further reduction of Keap1 and elevation of Nrf2 and SOD mRNA. These results showed the cardioprotective effects of ALA on DOX-induced cardiotoxicity in rats. The mechanisms might be associated with the enhancement of antioxidant defense system through activating Keap1/Nrf2 pathway and anti-apoptosis through activating protein kinase B/extracellular signal regulated kinase pathway. Our results suggested a promising future of ALA-based preventions and therapies for myocardial damage after administration of DOX.

Effect of increasing levels of bioflavonoids in broiler feed on plasma anti-oxidative potential, lipid metabolites, and fatty acid composition of meat

This study was conducted to investigate the supplemental effects of purified bioflavonoids (genistein and hesperidin), as potential alternatives to plant/herbs or synthetic antioxidants, individually and in combination for fatty acid profile, lipid metabolites, and antioxidant status of broilers. Three hundred sixty 1-d-old broilers were divided into 6 treatment groups: control (basal diet), G5 (5 mg of genistein per kg of feed), and H20 (20 mg hesperidin per kg of feed), whereas the other 3 groups were supplemented with a mixture of genistein and hesperidin (20% genistein + 80% hesperidin) having a dosage of 5 mg•kg(-1) (GH5), 10 mg•kg(-1) (GH10), and 20 mg•kg(-1) (GH20), respectively. Broilers were slaughtered at 42 d, and breast muscle, liver, and blood samples were collected. A dose-dependent increase (P < 0.05) was observed for plasma antioxidant parameters, including total antioxidant capacity, malondialdehyde production, and total superoxide dismutase activity. Cholesterol and triglyceride contents were found to decrease (P < 0.05) in serum and breast muscle. The proportion of total polyunsaturated fatty acids and the ratio of n-6 to n-3 fatty acids and polyunsaturated fatty acids to saturated fatty acids in breast muscles was significantly improved (P < 0.05) by increasing levels of dietary bioflavonoids. The current results implied that dietary bioflavonoids genistein and hesperidin could positively improve the fatty acid and lipid metabolite profile of broiler breast meat in a dose-dependent fashion. Thus, bioflavonoids could be a feasible alternative of antioxidant plants/herbs and synthetic feed additives for the production of healthier chicken meat.

n-3 Polyunsaturated fatty acids throughout the cancer trajectory: influence on disease incidence, progression, response to therapy and cancer-associated cachexia

Evidence from epidemiological studies suggests that diets rich in n-3 PUFA may be associated with reduced cancer risk. These observations have formed the rationale for exploring the mechanisms by which n-3 PUFA may be chemoprotective and have resulted in significant advances in our mechanistic understanding of n-3 PUFA action on tumour growth. Various interrelated and integrated mechanisms may be at work by which n-3 PUFA influence cancer at all stages of initiation, promotion, progression, and neoplastic transformation. More recently, experimental studies have reported enhanced tumour cell death with chemotherapy when fish oil is provided while toxic side effects to the host are reduced. Furthermore, cancer-associated wasting has been shown to be attenuated by fish oil supplementation. Clinical evidence suggests that the n-3 PUFA status of newly diagnosed cancer patients and individuals undergoing chemotherapy is low. Therefore, both the disease itself and therapeutic treatments may be contributing factors in the decline of n-3 PUFA status. Dietary supplementation to maintain and replenish n-3 PUFA status at key points in the cancer disease trajectory may provide additional health benefits and an enhanced quality of life. The present review will focus on and critically examine current research efforts related to the putative anti-cancer effects of n-3 PUFA and their suggested ability to palliate cancer-associated and treatment-associated symptoms.

Protective role of grape seed extract against doxorubicin-induced cardiotoxicity and genotoxicity in albino mice

In this study, the protective role of grape seed extract (GSE) against doxorubicin (DOX)-induced cardiotoxicity and genotoxicity has been evaluated in male Mus musculus var. albino mice. The micronucleus (MN) test in erythrocytes and the chromosome aberration (CA) test in bone marrow cells were used. Also, levels of reduced glutathione (GSH) and lipid peroxidation as malondialdehyde (MDA) in heart homogenates were measured, and in addition the changes in heart histology were investigated. The mice were randomly divided into six groups. Group I (negative control) received intraperitoneal injections of isotonic saline (0.02 mL/g) for 6 consecutive days, Group II received intraperitoneal injections of DOX (2.5 mg/kg of body weight, six doses every other day; cumulative dosage, 15 mg/kg of body weight) for 6 consecutive days, Group III received GSE (50 mg/kg of body weight, 21 doses every other day; cumulative dosage, 1,050 mg/kg of body weight) for 21 consecutive days, Group IV received GSE (150 mg/kg of body weight, 21 doses every other day; cumulative dosage, 3,150 mg/kg of body weight) for 21 consecutive days, Group V received GSE (50 mg/kg of body weight, 28 doses every other day; cumulative dosage, 1,400 mg/kg of body weight) for 28 consecutive days plus DOX (2.5 mg/kg of body weight, six doses every other day; cumulative dosage, 15 mg/kg of body weight) for 6 consecutive days, and Group VI received GSE (150 mg/kg of body weight, 28 doses every other day; cumulative dosage, 4,200 mg/kg of body weight) for 28 consecutive days plus DOX (2.5 mg/kg of body weight, six doses every other day; cumulative dosage, 15 mg/kg of body weight) for 6 consecutive days. DOX induced heart damage as indicated from a pronounced change in heart histology. In the DOX-treated group, there was a significant increase in MDA content in the heart homogenate, and the level of GSH was significantly decreased. DOX induced genotoxicity by increasing the number of aberrant metaphases (AMNs), MNs, and structural chromosomal aberrations (CAs) such as chromatid breaks, dicentrics, acentric fragments, and gaps and showed a detractive effect on the mitotic index (MI) of cells. Pretreatment with GSE before treatment with DOX significantly protected the heart tissue by ameliorating its antioxidant activity. In Groups V and VI, the MDA level of heart tissue was significantly decreased, and the GSH level was increased compared to the DOX-treated group. Moreover, GSE significantly protected bone marrow chromosomes from DOX-induced genotoxicity by reducing the total AMNs and the frequency of structural CAs. GSE treatment also decreased the frequency of MNs and increased the MI values. It could be concluded that GSE acts as a potent antioxidant to prevent heart damage and genotoxicity of bone marrow cells.

Green tea modulates alpha(1)-adrenergic stimulated glucose transport in cultured rat cardiomyocytes

alpha1-Adrenergic stimulation triggers glucose transport in the heart through the translocation of glucose transporter (GLUT) 1 and GLUT4 to plasma membranes, mediated by protein kinase C (PKC) isoforms. Evidence is emerging that dietary polyphenolic compounds may act not only as antioxidants but also by modulating PKC-mediated signaling. This study evaluated the ability of a green tea extract (GTE) to modulate alpha1-adrenoceptor-mediated glucose transport in rat cardiomyocytes. GTE supplementation decreased phenylephrine (PhE)-stimulated glucose uptake and GLUT4 recruitment. PhE stimulation activated PKC alpha, beta, delta, and epsilon, while GTE supplementation decreased the translocation of beta and delta isoforms, but not alpha and epsilon, supporting the notion that GTE directly affects PKC activation and is a beta and delta isoform-selective PKC inhibitor. Due to reactive oxygen species (ROS) involvement in pathological heart alterations, the observation that GTE is able to both inhibit effects originated by some PKC isoforms and counteract ROS deleterious effects could be important in the prevention/counteraction of these diseases.

Herbal medicine and cancer: an introductory overview

OBJECTIVES

To present Western herbal medicine from the perspective of a "food" model of herbs in contrast to the pharmaceutical "drug" model derived from mainstream medicine. Historical, political, and regulatory aspects of herbal medicine in the United States; core principles of herbal medicine in terms of the natural link between food and medicine; dietary chemopreventive plant compounds in the form of herbal medicines; and herb-drug interactions are briefly discussed, with an emphasis on beneficial interactions with conventional chemotherapy.

DATA SOURCES

Literature on dietary chemopreventive compounds; phytotherapeutic training and clinical practice.

CONCLUSION

Botanical medicine, based on dietary chemopreventive compounds plays an important role in integrative cancer treatment.

IMPLICATIONS FOR NURSING PRACTICE

Knowledge of the differences between herbal and conventional medicine in terms of a food, medicine, and poison model will help nurses facilitate patient decision-making choices in integrative cancer treatment.

Doxorubicin induces early lipid peroxidation associated with changes in glucose transport in cultured cardiomyocytes

Doxorubicin (DOX) has not only chronic, but also acute toxic effects in the heart, ascribed to the generation of reactive oxygen species (ROS). Focusing on the DOX-induced early biochemical changes in rat cardiomyocytes, we demonstrated that lipid peroxidation is an early event, in fact conjugated diene production increased after 1-h DOX exposure, while cell damage, evaluated as lactate dehydrogenase (LDH) release, was observed only later, when at least one third of the cell antioxidant defences were consumed. Cell pre-treatment with alpha-tocopherol (TC) inhibited both conjugated diene production and LDH release. In cardiomyocytes, DOX treatment caused a maximal increase in glucose uptake at 1 h, demonstrating that glucose transport may represent an early target for DOX. At longer times, as the cell damage become significant, the glucose uptake stimulation diminished. Immunoblotting of glucose transporter isoform GLUT1 in membranes after 1-h DOX exposure revealed an increase in GLUT1 amount similar to the increase in transport activity; both effects were inhibited by alpha TC. Early lipid peroxidation evokes an adaptive response resulting in an increased glucose uptake, presumably to restore cellular energy. The regulation of nutrient transport mechanisms in cardiomyocytes may be considered an early event in the development of the cardiotoxic effects of the anthracycline.