Curcumin potentiates doxorubicin-induced apoptosis in H9c2 cardiac muscle cells through generation of reactive oxygen species

A review of chemotherapeutic drugs-induced arrhythmia and potential intervention with traditional Chinese medicines

Significant advances in chemotherapy drugs have reduced mortality in patients with malignant tumors. However, chemotherapy-related cardiotoxicity increases the morbidity and mortality of patients, and has become the second leading cause of death after tumor recurrence, which has received more and more attention in recent years. Arrhythmia is one of the common types of chemotherapy-induced cardiotoxicity, and has become a new risk related to chemotherapy treatment, which seriously affects the therapeutic outcome in patients. Traditional Chinese medicine has experienced thousands of years of clinical practice in China, and has accumulated a wealth of medical theories and treatment formulas, which has unique advantages in the prevention and treatment of malignant diseases. Traditional Chinese medicine may reduce the arrhythmic toxicity caused by chemotherapy without affecting the anti-cancer effect. This paper mainly discussed the types and pathogenesis of secondary chemotherapeutic drug-induced arrhythmia (CDIA), and summarized the studies on Chinese medicine compounds, Chinese medicine Combination Formula and Chinese medicine injection that may be beneficial in intervention with secondary CDIA including atrial fibrillation, ventricular arrhythmia and sinus bradycardia, in order to provide reference for clinical prevention and treatment of chemotherapy-induced arrhythmias.

Doxorubicin conjugates: a practical approach for its cardiotoxicity alleviation

INTRODUCTION

Doxorubicin (DOX) emerges as a cornerstone in the arsenal of potent chemotherapeutic agents. Yet, the clinical deployment of DOX is tarnished by its proclivity to induce severe cardiotoxic effects, culminating in heart failure and other consequential morbidities. In response, a panoply of strategies has undergone rigorous exploration over recent decades, all aimed at attenuating DOX's cardiotoxic impact. The advent of encapsulating DOX within lipidic or polymeric nanocarriers has yielded a dual triumph, augmenting DOX's therapeutic efficacy while mitigating its deleterious side effects.

AREAS COVERED

Recent strides have spotlighted the emergence of DOX conjugates as particularly auspicious avenues for ameliorating DOX-induced cardiotoxicity. These conjugates entail the fusion of DOX through physical or chemical bonds with diminutive natural or synthetic moieties, polymers, biomolecules, and nanoparticles. This spectrum encompasses interventions that impinge upon DOX's cardiotoxic mechanism, modulate cellular uptake and localization, confer antioxidative properties, or refine cellular targeting.

EXPERT OPINION

The endorsement of DOX conjugates as a compelling stratagem to mitigate DOX-induced cardiotoxicity resounds from this exegesis, amplifying safety margins and the therapeutic profile of this venerated chemotherapeutic agent. Within this ambit, DOX conjugates stand as a beacon of promise in the perpetual pursuit of refining chemotherapy-induced cardiac compromise.

Protective effects of natural compounds against paraquat-induced pulmonary toxicity: the role of the Nrf2/ARE signaling pathway

Paraquat (PQ) is a toxic herbicide to humans. Once absorbed, it accumulates in the lungs. PQ has been well documented that the generation of reactive oxygen species (ROS) is the main mechanism of its toxicity. Oxidative damage of PQ in lungs is represented as generation of cytotoxic and fibrotic mediators, interruption of epithelial and endothelial barriers, and inflammatory cell infiltration. No effective treatment for PQ toxicity is currently available. Several studies have shown that natural compounds (NCs) have the potential to alleviate PQ-induced pulmonary toxicity, due to their antioxidant and anti-inflammatory effects. NCs function as protective agents through stimulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Elevation of Nrf2 levels leads to the expression of its downstream enzymes such as SOD, CAT, and HO-1. The hypothesized role of the Nrf2/ARE signaling pathway as the protective mechanism of NCs against PQ-induced pulmonary toxicity is reviewed.

A systematic review of the protective effects of silymarin/silibinin against doxorubicin-induced cardiotoxicity

PURPOSE

Although doxorubicin chemotherapy is commonly applied for treating different malignant tumors, cardiotoxicity induced by this chemotherapeutic agent restricts its clinical use. The use of silymarin/silibinin may mitigate the doxorubicin-induced cardiac adverse effects. For this aim, the potential cardioprotective effects of silymarin/silibinin against the doxorubicin-induced cardiotoxicity were systematically reviewed.

METHODS

In this study, we performed a systematic search in accordance with PRISMA guideline for identifying all relevant studies on "the role of silymarin/silibinin against doxorubicin-induced cardiotoxicity" in different electronic databases up to June 2022. Sixty-one articles were obtained and screened based on the predefined inclusion and exclusion criteria. Thirteen eligible papers were finally included in this review.

RESULTS

According to the echocardiographic and electrocardiographic findings, the doxorubicin-treated groups presented a significant reduction in ejection fraction, tissue Doppler peak mitral annulus systolic velocity, and fractional shortening as well as bradycardia, prolongation of QT and QRS interval. However, these echocardiographic abnormalities were obviously improved in the silymarin plus doxorubicin groups. As well, the doxorubicin administration led to induce histopathological and biochemical changes in the cardiac cells/tissue; in contrast, the silymarin/silibinin co-administration could mitigate these induced alterations (for most of the cases).

CONCLUSION

According to the findings, it was found that the co-administration of silymarin/silibinin alleviates the doxorubicin-induced cardiac adverse effects. Silymarin/silibinin exerts its cardioprotective effects via antioxidant, anti-inflammatory, anti-apoptotic activities, and other mechanisms.

Dietary Antioxidant Curcumin Mitigates CuO Nanoparticle-Induced Cytotoxicity through the Oxidative Stress Pathway in Human Placental Cells

The placenta is an important organ that maintains a healthy pregnancy by transporting nutrients to the fetus and removing waste from the fetus. It also acts as a barrier to protect the fetus from hazardous materials. Recent studies have indicated that nanoparticles (NPs) can cross the placental barrier and pose a health risk to the developing fetus. The high production and widespread application of copper oxide (CuO) NPs may lead to higher exposure to humans, raising concerns of health hazards, especially in vulnerable life stages, e.g., pregnancy. Oxidative stress plays a crucial role in the pathogenesis of adverse pregnancy outcomes. Due to its strong antioxidant activity, dietary curcumin can act as a therapeutic agent for adverse pregnancy. There is limited knowledge on the hazardous effects of CuO NPs during pregnancy and their mitigation by curcumin. This study aimed to investigate the preventive effect of curcumin against CuO NP-induced toxicity in human placental (BeWo) cells. CuO NPs were synthesized by a facile hydrothermal process and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence techniques. We observed that curcumin did not induce toxicity in BeWo cells (1-100 µg/mL for 24 h), whereas CuO NPs decreased the cell viability dose-dependently (5-200 µg/mL for 24 h). Interestingly, CuO NP-induced cytotoxicity was effectively mitigated by curcumin co-exposure. The apoptosis data also exhibited that CuO NPs modulate the expression of several genes (p53, bax, bcl-2, casp3, and casp9), the activity of enzymes (caspase-3 and -9), and mitochondrial membrane potential loss, which was successfully reverted by co-treatment with curcumin. The mechanistic study suggested that CuO-induced reactive oxygen species generation, lipid peroxidation, and higher levels of hydrogen peroxide were significantly alleviated by curcumin co-exposure. Moreover, glutathione depletion and the lower activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase) were effectively mitigated by curcumin. We believe this is the first report exhibiting that CuO-induced toxicity in BeWo cells can be effectively alleviated by curcumin. The pharmacological potential of dietary curcumin in NP-induced toxicity during pregnancy warrants further investigation.

A systematic review of nonclinical studies on the effect of curcumin in chemotherapy-induced cardiotoxicity

BACKGROUND

Various anticancer drugs are effective therapeutic agents for cancer treatment; however, they cause severe toxicity in body organs. Cardiotoxicity is one of the most critical side effects of these drugs. Based on various findings, turmeric extract has positive effects on cardiac cells.

OBJECTIVE

This study aims to evaluate how curcumin as the main component of turmeric may affect chemotherapy-induced cardiotoxicity.

METHOD

Database search was performed up to April 2021 using "curcumin OR turmeric OR Curcuma longa" and "chemotherapy-induced cardiac disease," including all their equivalents and similar terms. After screening the total articles obtained from the electronic databases, 25 relevant articles were included in this systematic review.

RESULTS

The studies demonstrate lower body weight and increased mortality rates due to doxorubicin administration. Besides, cancer therapeutic agents induced various morphological and biochemical abnormalities compared to the non-treated groups. Based on most of the obtained results, curcumin at nontoxic doses can protect the cardiac cells mainly through modulating antioxidant capacity, regulation of cell death, and anti-inflammatory effects. Nevertheless, according to a minority of findings, curcumin increases the susceptibility of the rat cardiomyoblast cell line (H9C2) to apoptosis triggered by doxorubicin.

CONCLUSION

According to most nonclinical studies, curcumin can have the potential of cardioprotective effects against cardiotoxicity induced by chemotherapy. However, based on limited, contradictory findings demonstrating the function of curcumin in potentiating doxorubicin-induced cardiotoxicity, well-designed studies are needed to evaluate the safety and effectiveness of treatment with new formulations of this compound during cancer therapy.

The cardioprotective effects of nano-curcumin against doxorubicin-induced cardiotoxicity: A systematic review

Although the chemotherapeutic drug, doxorubicin, is commonly used to treat various malignant tumors, its clinical use is restricted because of its toxicity especially cardiotoxicity. The use of curcumin may alleviate some of the doxorubicin-induced cardiotoxic effects. Especially, using the nano-formulation of curcumin can overcome the poor bioavailability of curcumin and enhance its physicochemical properties regarding its efficacy. In this study, we systematically reviewed the potential cardioprotective effects of nano-curcumin against the doxorubicin-induced cardiotoxicity. A systematic search was accomplished based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for the identification of all relevant articles on "the role of nano-curcumin on doxorubicin-induced cardiotoxicity" in the electronic databases of Scopus, PubMed, and Web of Science up to July 2021. One hundred and sixty-nine articles were screened following a predefined set of inclusion and exclusion criteria. Ten eligible scientific papers were finally included in the present systematic review. The administration of doxorubicin reduced the body and heart weights of mice/rats compared to the control groups. In contrast, the combined treatment of doxorubicin and nano-curcumin increased the body and heart weights of animals compared with the doxorubicin-treated groups alone. Furthermore, doxorubicin could significantly induce the biochemical and histological changes in the cardiac tissue; however, coadministration of nano-curcumin formulation demonstrated a pattern opposite to the doxorubicin-induced changes. The coadministration of nano-curcumin alleviates the doxorubicin-induced cardiotoxicity through various mechanisms including antioxidant, anti-inflammatory, and antiapoptotic effects. Also, the cardioprotective effect of nano-curcumin formulation against doxorubicin-induced cardiotoxicity was higher than free curcumin.

In Vitro and In Vivo Cardioprotective Effects of Curcumin against Doxorubicin-Induced Cardiotoxicity: A Systematic Review

Objective

This study aimed to review the potential chemoprotective effects of curcumin against the doxorubicin-induced cardiotoxicity.

Methods

According to the PRISMA guideline, a comprehensive systematic search was performed in different electronic databases (Web of Science, PubMed, and Scopus) up to July 2021. One hundred and sixty-four studies were screened in accordance with a predefined set of inclusion and exclusion criteria. Eighteen eligible articles were finally included in the current systematic review.

Results

According to the in vitro and in vivo findings, it was found that doxorubicin administration leads to decreased cell survival, increased mortality, decreased bodyweight, heart weight, and heart to the bodyweight ratio compared to the control groups. However, curcumin cotreatment demonstrated an opposite pattern in comparison with the doxorubicin-treated groups alone. Other findings showed that doxorubicin significantly induces biochemical changes in the cardiac cells/tissue. Furthermore, the histological changes on the cardiac tissue were observed following doxorubicin treatment. Nevertheless, for most of the cases, these biochemical and histological changes mediated by doxorubicin were reversed near to control groups following curcumin coadministration.

Conclusion

It can be mentioned that coadministration of curcumin alleviates the doxorubicin-induced cardiotoxicity. Curcumin exerts these cardioprotective effects through different mechanisms of antioxidant, antiapoptosis, and anti-inflammatory. Since the finding presented in this systematic review are based on in vitro and in vivo studies, suggesting the use of curcumin in cancer patients as a cardioprotector agent against cardiotoxicity mediated by doxorubicin requires further clinical studies.

The cardioprotective effects of hydrogen sulfide by targeting endoplasmic reticulum stress and the Nrf2 signaling pathway: A review

Cardiac diseases are emerging due to lifestyle, urbanization, and the accelerated aging process. Oxidative stress has been associated with cardiac injury progression through interference with antioxidant strategies and endoplasmic reticulum (ER) function. Hydrogen sulfide (H₂ S) is generated endogenously from l-cysteine in various tissues including heart tissue. Pharmacological evaluation of H₂ S has suggested a potential role for H₂ S against diabetic cardiomyopathy, ischemia/reperfusion injury, myocardial infarction, and cardiotoxicity. Nuclear factor E2-related factor 2 (Nrf2) activity is crucial for cell survival in response to oxidative stress. H₂ S up-regulates Nrf2 expression and its related signaling pathway in myocytes. H₂ S also suppresses the expression and activity of ER stress-related proteins. H₂ S has been reported to improve various cardiac conditions through antioxidant and anti-ER stress-related activities.

Curcumin-coated gold nanoparticles attenuate doxorubicin-induced cardiotoxicity via regulating apoptosis in a mouse model

Doxorubicin (DOX) is one of the most widely used chemotherapy agents; however, its nonselective effect causes cardiotoxicity. Curcumin (Cur), a well known dietary polyphenol, could exert a significant cardioprotective effect, but the biological application of this substance is limited by its chemical insolubility. To overcome this limitation, in this study, we synthesised gold nanoparticles based on Cur (Cur-AuNPs). Ultraviolet-visible (UV-Vis) absorbance spectroscopy and transmission electron microscopy (TEM) were performed for the characterisation of synthesised NPs, and Fourier transform infrared (FTIR) spectroscopy were applied to detect Cur on the surface of AuNPs. Its cytotoxicity effect on H9c2 cells was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The biological efficacy of Cur-AuNPs was assessed after acute cardiotoxicity induction in BALB/c mice with DOX injection. The serum biomarkers, myocardial histological changes, and cardiomyocyte apoptosis were then measured. The results revealed that the heart protection by Cur-AuNPs is more effective than Cur alone. Heart protective effect of Cur-AuNPs was evident both in the short-term (24 hours) and long-term (14 days) study. The results of Cur-AuNPs400 after 24 hours of toxicity induction displayed the reduction of the cardiac injury serum biomarkers (LDH, CK-MB, cTnI, ADT, and ALT) and apoptotic proteins (Bax and Caspase-3), as well as increase of Bcl-2 anti-apoptotic proteins without any sign of interfibrillar haemorrhage and intercellular spaces in the heart tissue microscopic images. Our long-term study signifies that Cur-AuNPs400 in DOX-intoxicated mice could successfully inhibit body and heart weight loss in comparison to DOX group.

Nuciferine Attenuates Doxorubicin-Induced Cardiotoxicity: An In Vitro and In Vivo Study

Chemotherapeutic drugs are a known factor that impairs the system of life due to their severe side effects. A more worrying fact is that the patients administered with doxorubicin fall under the risk of cardiotoxicity. The evolution of exploring plant-derived compounds is a possible way to combat health issues in therapeutic applications. Hence, this study focuses on the protective effect of plant-based compound nuciferine (NFN) against doxorubicin-induced cardiotoxicity in both in vitro and in vivo models. In this investigation, nuciferine significantly reduces DOX-mediated cardiotoxicity by mitigating reactive oxygen species, thereby preventing DNA fragmentation, regulating apoptosis genes and reducing the caspase 3/7 levels in vitro. Besides, nuciferine has shown significant protection against DOX-induced cardiac impairment and the upregulation of cardiogenic markers in vivo. The DOX-induced oxidative stress can be mitigated via enhancing the endogenous antioxidants, thereby controlling ROS-mediated apoptosis. In virtue of these potential features, nuciferine can be a budding candidate to address therapeutic needs.

Protective effects of curcumin on chemical and drug-induced cardiotoxicity: a review

Cardiotoxicity is a major adverse effect that can be induced by both therapeutic agents and industrial chemicals. The pathogenesis of such cardiac damage is multifactorial, often injuring the cardiac tissue by generating free radicals, oxidative stress, and/or inflammation. Curcumin (CUR) is a bright yellow chemical produced by Curcuma longa plants. It is the principal curcuminoid of turmeric (Curcuma longa), a member of the ginger family, Zingiberaceae. Administration of CUR has been reported to ameliorate the chemical and drug-induced cardiac injury in several studies. CUR has been suggested to act as an effective candidate against oxidative stress and inflammation in heart tissue via regulation of Nrf2 and suppression of p38 MAPK/NF-κB and NLRP3 inflammasomes. The anti-apoptotic properties of CUR have also been reported to modulate the AMPK, Akt, JNK, and ERK signaling pathways. This review explores the potential protective effects of CUR regarding the detrimental effects often observed in cardiac tissue following exposure to several chemicals including drugs.

Curcumin as a Natural Remedy for Atherosclerosis: A Pharmacological Review

Curcumin, a natural polyphenolic compound present in Curcuma longa L. rhizomes, shows potent antioxidant, anti-inflammatory, anti-cancer, and anti-atherosclerotic properties. Atherosclerosis is a comprehensive term for a series of degenerative and hyperplasic lesions such as thickening or sclerosis in large- and medium-sized arteries, causing decreased vascular-wall elasticity and lumen diameter. Atherosclerotic cerebro-cardiovascular disease has become a major concern for human health in recent years due to its clinical sequalae of strokes and heart attacks. Curcumin concoction treatment modulates several important signaling pathways related to cellular migration, proliferation, cholesterol homeostasis, inflammation, and gene transcription, among other relevant actions. Here, we provide an overview of curcumin in atherosclerosis prevention and disclose the underlying mechanisms of action of its anti-atherosclerotic effects.

The Anticancer Properties of Artemisia aucheri Boiss Extract on HT29 Colon Cancer Cells

BACKGROUND

Colon cancer is one of the most common cancers in the world, and efforts toward its treatment have not been completely successful. In recent years, more attention has been focused on herbal medicine (HM) due to their anticancer and cytotoxic properties. This study investigated the anticancer and antioxidant effects of Artemisia aucheri (A. aucheri) Boiss extract against HT29 colon cancer cells compared with HEK239 natural cells.

METHODS

This study was performed on human HT29 colon cancer cells. Various doses of 0, 10, 100, 500, and 1000 μg/ml of A. aucheri extract were subjected to cells at specified time intervals. After treatment, the trypan blue test was employed to determine the viability of the cells. MTT and annexin tests were used to determine cell viability and the apoptosis induced by the extract. Malondialdehyde (MDA) testing was applied to investigate the antioxidant properties of the extract on fatty acids. Data analysis was performed using SPSS version 22. One-way ANOVA and paired comparison tests were employed for data analysis.

RESULTS

The highest cytotoxicity effect of A. aucheri extract was observed at 1000 μg/ml (80.63 ± 3.66) being dose-dependent compared with the control in both cell lines (p < 0.001). Additionally, the survival rate of HT29 (IC50 = 57.88 μg/ml) and HEK (IC50 = 295 μg/ml) cancer cells decreased with increasing concentration of A. aucheri (the lowest cell viability was at 1000 μg/ml). Furthermore, the induction of membrane lipid peroxidation was significantly higher in HT29 compared with the control (p < 0.001). Another cytotoxic mechanism for the extract was the induction of apoptosis being significantly higher in HT29 colon cancer cells compared with the control group (p < 0.001).

CONCLUSION

Cytotoxic effects of A. aucheri extract were dose-dependent. This HM exerted cytotoxic effects against HT29 cells through the induction of membrane lipid peroxidation and apoptosis.

Nuciferine from Nelumbo nucifera Gaertn. attenuates isoproterenol-induced myocardial infarction in Wistar rats

The study explored the cardioprotective role of the methanolic leaf extract of Nelumbo nucifera and nuciferine against isoproterenol-induced myocardial infarction (MI) in Wistar rats. Pretreatment with leaf extract and nuciferine (200 and 20 mg/kg body weight, respectively) against MI induced by isoproterenol (85 mg/kg body weight) significantly decreased heart weight; levels of cardiac markers such as lactate dehydrogenase and creatine kinase-MB were similar to those in controls. The treatment significantly increased the content of endogenous antioxidants and decreased lipid peroxidation in all treated groups. Treated groups showed a significant reduction in heartbeats per minute as compared with the MI-induced positive control. The MI-induced group showed pathological implications such as tachycardia, left atrial enlargement, and anterolateral ST-elevated MI, which were absent in treated groups. Histology confirmed that the leaf extract and nuciferine prevented structural abnormality and inflammation in heart and liver tissues of treated groups. On in silico analysis, nuciferine showed stronger binding interaction with both β₁ and β₂ adrenergic receptors than isoproterenol. Hence, the leaf extract of N. nucifera and nuciferine could be used as plant-based cardioprotective agents.

A review on the protective effects of naringenin against natural and chemical toxic agents

Naringenin (NRG), as a flavanone from flavonoids family, is widely found in grapefruit, lemon tomato, and Citrus fruits. NRG has shown strong anti-inflammatory and antioxidant activities in body organs via mechanisms such as enhancement of glutathione S-transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activity, but reduction of serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and malondialdehyde (MDA). Furthermore, NRG anti-apoptotic potential was indicated to be mediated by regulating B-cell lymphoma (Bcl-2), Bcl-2-associated X protein (Bax) and caspase3/9. Overall, these properties make NRG a highly fascinating compound with beneficial pharmacological effects. Based on the literature, NRG-induced protective effects against toxicities produced by natural toxins, pharmaceuticals, heavy metals, and environmental chemicals, were mainly mediated via suppression of lipid peroxidation, oxidative stress (through boosting the antioxidant arsenal), and inflammatory factors (e.g., TNF-α, interleukin [IL]-6, IL-10, and IL-12), and activation of PI3K/Akt and MAPK survival signaling pathways. Despite considerable body of evidence on protective properties of NRG against a variety of toxic compounds, more well-designed experimental studies and particularly, clinical trials are required before reaching a concrete conclusion. The present review discusses how NRG protects against the above-noted toxic compounds.

Endoplasmic reticulum stress in doxorubicin-induced cardiotoxicity may be therapeutically targeted by natural and chemical compounds: A review

Doxorubicin (DOX) is a chemotherapeutic agent with marked, dose-dependent cardiotoxicity that leads to tachycardia, atrial and ventricular arrhythmia, and irreversible heart failure. Induction of the endoplasmic reticulum (ER) which plays a major role in protein folding and calcium homeostasis was reported as a key contributor to cardiac complications of DOX. This article reviews several chemical compounds that have been shown to regulate DOX-induced inflammation, apoptosis, and autophagy via inhibition of ER stress signaling pathways, such as the IRE1α/ASK1/JNK, IRE1α/JNK/Beclin-1, and CHOP pathways.

Natural compounds against cytotoxic drug-induced cardiotoxicity: A review on the involvement of PI3K/Akt signaling pathway

Cardiotoxicity is a critical concern in the use of several cytotoxic drugs. Induction of apoptosis, inflammation, and autophagy following dysregulation of the PI3K/Akt signaling pathway contributes to the cardiac damage induced by these drugs. Several natural compounds (NCs), including ferulic acid, gingerol, salvianolic acid B, paeonol, apigenin, calycosin, rutin, neferine, higenamine, vincristine, micheliolide, astragaloside IV, and astragalus polysaccharide, have been reported to suppress cytotoxic drug-induced cardiac injury. This article reviews these NCs that have been reported to have a protective effect against cytotoxic drug-induced cardiotoxicity through regulation of the PI3K/Akt signaling pathway.

Natural compounds against doxorubicin-induced cardiotoxicity: A review on the involvement of Nrf2/ARE signaling pathway

Cardiotoxicity is the main concern for long-term use of the doxorubicin (DOX). Reactive oxygen species (ROS) generation leads to oxidative stress that significantly contributes to the cardiac damage induced by DOX. The nuclear factor erythroid 2-related factor (Nrf2) acts as a protective player against DOX-induced myocardial oxidative stress. Several natural compounds (NCs) with anti-oxidative effects, were examined to suppress DOX cardiotoxicity such as asiatic acid, α-linolenic acid, apigenin, baicalein, β-lapachone, curdione, dioscin, ferulic acid, Ganoderma lucidum polysaccharides, genistein, ginsenoside Rg3, indole-3-carbinol, naringenin-7-O-glucoside, neferine, p-coumaric acid, pristimerin, punicalagin, quercetin, sulforaphane, and tanshinone IIA. The present article, reviews NCs that showed protective effects against DOX-induced cardiac injury through induction of Nrf2 signaling pathway.

Doxorubicin Cytotoxicity in Differentiated H9c2 Cardiomyocytes: Evidence for Acute Mitochondrial Superoxide Generation

Although a mitochondrial redox-cycling superoxide-generating mechanism for the cardiotoxicity of doxorubicin was suggested from experiments with isolated mitochondria, its occurrence and contribution to cytotoxicity in intact cardiomyocytes is not fully established. Therefore, we determined the immediate and delayed effects of doxorubicin on the generation of reactive oxygen species (ROS) and cytotoxicity in differentiated H9c2 cardiomyocytes. Although relatively short incubations (3 or 6 h) with 1 or 5 µM doxorubicin did not acutely decrease cell survival, exposure to 5 µM doxorubicin for 3 h was sufficient to cause a significant delayed decrease in cell survival after an additional 24 h without doxorubicin. Mitochondrial superoxide generation was observed to increase within 30 min of incubation with 5 µM doxorubicin. Increased intracellular ROS generation, decreased mitochondrial metabolic activity, and decreased mitochondrial membrane potential (MMP) were observed after more extended periods (6-12 h). Overall, these observations support that the toxicity of doxorubicin to differentiated cardiomyocytes involves acute mitochondrial superoxide generation with subsequent intracellular ROS generation, mitochondrial dysfunction, and cell death.

Vanillin Prevents Doxorubicin-Induced Apoptosis and Oxidative Stress in Rat H9c2 Cardiomyocytes

Doxorubicin (doxo) is an effective anticancer compound in several tumor types. However, as a consequence of oxidative stress induction and ROS overproduction, its high cardiotoxicity demands urgent attention. Vanillin possesses antioxidant, antiproliferative, antidepressant and anti-glycating properties. Therefore, we investigated the potential vanillin protective effects against doxo-induced cardiotoxicity in H9c2 cells. Using multiparametric approach, we demonstrated that vanillin restored both cell viability and damage in response to doxo exposure. Contextually, vanillin decreased sub-G1 appearance and caspase-3 and PARP1 activation, reducing the doxo-related apoptosis induction. From a mechanistic point of view, vanillin hindered doxo-induced ROS accumulation and impaired the ERK phosphorylation. Notably, besides the cardioprotective effects, vanillin did not counteract the doxo effectiveness in osteosarcoma cells. Taken together, our results suggest that vanillin ameliorates doxo-induced toxicity in H9c2 cells, opening new avenues for developing alternative therapeutic approaches to prevent the anthracycline-related cardiotoxicity and to improve the long-term outcome of antineoplastic treatment.

Lotusine, an alkaloid from Nelumbo nucifera (Gaertn.), attenuates doxorubicin-induced toxicity in embryonically derived H9c2 cells

Cardiotoxicity is the major challenge in chemotherapy with doxorubicin (DOX) or adriamycin. Doxorubicin manifests oxidative stress via an uncontrolled progression of reactive oxygen species in cardiomyocytes; thereby, dysregulation and dysfunction of myocardium thus lead to apoptosis. Several attempts have been made to overcome this side effect in patients with antioxidant-rich supplements to control the free radicals. Plant-based or plant-derived compounds pay more attention to cure such complications in patients for supporting the treatment, revitalizing or regulating the normal metabolism. Hence, our study focused on pretreatment of embryonically derived rat cardiomyocytes (H9c2) with phytocompound lotusine to prevent DOX-mediated oxidative stress. From the experiment, the DOX-exposed cells have shown morphological abnormalities such as reduced cell size, shrinkage, blebbing, and chromatin condensation, whereas no such deformities were observed in lotusine-pretreated cells even after the exposure to DOX. Increased endogenous antioxidants with reduced lipid peroxidation were observed in lotusine-pretreated cells, whereas the antioxidants were reduced along with increased lipid peroxidation in doxorubicin-exposed cells. A decreased reactive oxygen species generation was evidenced with the 2',7'-dichlorofluorescein diacetate (DCF-DA) staining method. In qPCR analysis, the lotusine-pretreated cells have mitigated doxorubicin-mediated apoptosis by downregulating the pro-apoptotic gene Bax and apoptotic executor caspase-3. It was further confirmed with the luminometric assay, which resulted in lesser luminescence in lotusine-pretreated cells, whereas higher luminescence was recorded in doxorubicin-alone-treated cells. In conclusion, the present study revealed that the lotusine pretreatment has exhibited potential cardioprotective activity against DOX-induced oxidative stress by increasing the intracellular antioxidant defense.

Co-delivery of Doxorubicin and Curcumin with Polypeptide Nanocarrier for Synergistic Lymphoma Therapy

The traditional chemotherapy, including Adriamycin (Doxorubicin, DOX), is widely used and is part of the first-line chemotherapy of invasive B cell lymphoma. DOX is nonselective cytotoxic drug and has many adverse effects, which limit its clinical application in combination with other anti-cancer drugs. Optimization of the delivery system targeting tumor microenvironment could be a feasible approach that may have significant clinical significance. Further, combination of DOX with other anticancer drugs, such as curcumin, can enhance the synergistic effects, possibly through epigenetic mechanisms. Hence, we evaluated the efficacy and toxicity of novel nanoparticles that enable the co-delivery of DOX and curcumin in the treatment of invasive B cell lymphoma both in vivo and vitro. The polymer nano materials [mPEG-b-P(Glu-co-Phe)] was used to co-load DOX and curcumin (CUR): L-DOX + CUR. DOX signal was measured to determine the ability of the drugs entering the cells by flow cytometry, and the different enrichment areas in the cells were directly observed by confocal microscope. The toxicity of LDOX + CUR was tested by CCK-8 assay in different cells, and the synergistic coefficients were calculated. The cell apoptosis and the possible mechanisms of apoptosis pathways regulation by L-DOX + CUR were examined using flow cytometry and Western Blot. The MTD (maximum tolerable dose) test was performed in mice. Tumor-bearing SCID mice (i.e., BJAB cell) were used to evaluate the in vivo efficacy of L-DOX + CUR. L-DOX + CUR, was prepared successfully, and the mole ratio of DOX and CUR fixed in 1.0:1.2. (DOX loading rate 9.7%, CUR loading rate 8.1%). L-DOX + CUR exhibited increased intracellular delivery and the main enrichment area of DOX was nucleus. L-DOX + CUR increased cytotoxicity, induced higher rates of apoptosis, and had synergistic effect, especially in BJAB cells (min CI 0.019). It even had epigenetic effect and affected miRNA levels favorably by down-regulating miR-21, miR-199a and up-regulating miR-98 and miR-200c. Additionally, L-DOX + CUR increased MTD in Kunming mice (i.e., 25 mg/kg), compared to DOX (10 mg/kg) and L-DOX (20 mg/kg). In BJAB cell bearing SCID mice, L-DOX + CUR treatment suppressed tumor growth compared to DOX or L-DOX alone, and exhibited less weight loss in mice. We developed new polymer nanoparticles-mPEG-b-P (Glu-co-Phe) co-loaded with DOX and DUR. L-DOX + CUR exhibited synergistic cytotoxic and apoptotic effects on invasive B cell lymphoma. Treatment of L-DOX + CUR potentiated tumor killing in xenografts and reduced toxicity in vivo.

Teneligliptin prevents doxorubicin-induced inflammation and apoptosis in H9c2 cells

Doxorubicin is a common chemotherapy treatment with numerous negative ramifications of use such as nephropathy and radiation-induced cardiotoxicity. Doxorubicin has been shown to cause overexpression of proinflammatory cytokines including MCP-1 and IL-1β via activation of the NF-κB pathway. Furthermore, apoptosis marked by dysregulation of the Bax/Bcl-2 ratio and oxidative stress and the production of reactive oxygen species (ROS) are also exacerbated by doxorubicin administration. Teneligliptin is part of the wider dipeptidyl peptidase-4 (DPP-4) inhibitor family which has until recently been almost exclusively used to treat type 2 diabetes mellitus. DPP-4 inhibitors such as teneligliptin control the overexpression of glucagon-like peptidase 1 (GLP-1) which has the downstream effects of general insulin resistance and high blood sugar levels. Our findings indicate a significant protective effect of teneligliptin against the aftereffects of doxorubicin as a chemotherapy treatment. This protective effect includes but is not limited to the reduction of inflammation and the mitigation of dysregulated apoptosis, as evidenced by reduced expression of IL-1β and MCP-1, inhibition of NF-κB activation, and improvement of the Bax/Bcl-2 ratio. The aim of the present study was to establish teneligliptin as a potentially useful agent for the treatment of radiation-induced cardiotoxicity, and our findings support this notion.

Protective effect of Nelumbo nucifera (Gaertn.) against H2O2-induced oxidative stress on H9c2 cardiomyocytes

Ischemic heart disease (IHD), a severe condition of myocardium facing impediment in the supply of basic needs for cellular metabolism is caused by atherosclerosis. Though statin drugs could control the use of surgery on IHD patients, the complete rehabilitation or prophylaxis can be achieved through herbal-based medicines viz. either in the form of crude extract or pure phytocompounds. In the present study, pretreatment with leaf extract of Nelumbo nucifera Gaertn. was investigated for cardioprotective activity-in vitro by mitigating H₂O₂-induced oxidative stress. Analysis such as estimation of antioxidants, lipid peroxidation, and DNA fragmentation assay revealed significant protective effect of plant extract on cardiomyocytes. Reactive oxygen species detection was done by using 2',7'-dichlorofluorescein diacetate, apoptosis detection with Acridine Orange/Ethidium Bromide and nuclear damage detection by diamidino-2-phenylindole which confirmed the protective effect of N. nucifera extract. In addition, gene expression studies of apoptotic regulatory genes (Bcl2 and Cas-9) resulted in significant protection of nucifera extract pretreated and maintained cells. To conclude, in vitro cardioprotective activity of N. nucifera against H₂O₂ induced oxidative stress was achieved at the concentration of 50 µg/ml. Therefore, major phytocompounds present in extract could be beneficial in managing cardiac complications in the future.

Improved pharmacokinetics and reduced side effects of doxorubicin therapy by liposomal co-encapsulation with curcumin

The goal of the current study was to investigate the pharmacokinetic profile, tissue distribution and adverse effects of long-circulating liposomes (LCL) with curcumin (CURC) and doxorubicin (DOX), in order to provide further evidence for previously demonstrated enhanced antitumor efficacy in colon cancer models. The pharmacokinetic studies were carried out in healthy rats, following the i.v. injection of a single dose of LCL-CURC-DOX (1 mg/kg DOX). For the tissue distribution study, DOX concentration in tumours, heart and liver were measured after the administration of two i.v. doses of LCL-CURC-DOX (2.5 mg/kg DOX and 5 mg/kg CURC) to Balb/c mice bearing C26 colon tumours. Markers of murine cardiac and hepatic oxidative status were determined to provide additional insights into the benefit of co-encapsulating CURC and DOX in LCL over DOX-induced adverse effects in these organs. The current study demonstrated that the liposomal association of CURC and DOX effectively improved the pharmacokinetics and biodistribution of DOX, limiting its side effects, via CURC-dependent antioxidant effects.

Combinations of the antioxidants sulforaphane or curcumin and the conventional antineoplastics cisplatin or doxorubicin as prospects for anticancer chemotherapy

Drugs used in clinical oncology have narrow therapeutic indices with adverse toxicity often involving oxidative damage. Chemoresistance to these conventional antineoplastics is usually mediated by oxidative stress-upregulated pathways such as those of nuclear factor-kappa B (NF-κB) and hypoxia-inducible factor-1 alpha (HIF-1α). Accordingly, the use of antioxidants in combinational approaches has begun to be considered for fighting cancer because of both the protective role against adverse effects and the ability to sensitize chemoresistant cancer cells. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been identified as a mediator of the cytoprotection but it is not regularly associated with tumor chemosensitization. However, some Nrf2 inducers could be exerting cytoprotective and chemosensitizing roles through a simple integrated mechanism in which the cellular level of reactive oxygen species is controlled, thus inhibiting the oxidative damage in non-target tissues and the tumor chemoresistance mediated by NF-κB or HIF-1α. As examples to show the general idea of this antioxidant combination chemotherapy, this review explores the preclinical information available for four combinations, each composed by a paradigmatic oncological drug (cisplatin or doxorubicin) and a recognized antioxidant (sulforaphane or curcumin). The issues for translating these outcomes to clinical trials are briefly discussed.

Copaiba Oil Attenuates Right Ventricular Remodeling by Decreasing Myocardial Apoptotic Signaling in Monocrotaline-Induced Rats

There is an increase in oxidative stress and apoptosis signaling during the transition from hypertrophy to right ventricular (RV) failure caused by pulmonary arterial hypertension (PAH) induced by monocrotaline (MCT). In this study, it was evaluated the action of copaiba oil on the modulation of proteins involved in RV apoptosis signaling in rats with PAH. Male Wistar rats (±170 g, n = 7/group) were divided into 4 groups: control, MCT, copaiba oil, and MCT + copaiba oil. PAH was induced by MCT (60 mg/kg intraperitoneally) and, 7 days later, treatment with copaiba oil (400 mg/kg by gavage) was given for 14 days. Echocardiographic and hemodynamic measurements were performed, and the RV was collected for morphometric evaluations, oxidative stress, apoptosis, and cell survival signaling, and eNOS protein expression. Copaiba oil reduced RV hypertrophy (24%), improved RV systolic function, and reduced RV end-diastolic pressure, increased total sulfhydryl levels and eNOS protein expression, reduced lipid and protein oxidation, and the expression of proteins involved in apoptosis signaling in the RV of MCT + copaiba oil as compared to MCT group. In conclusion, copaiba oil reduced oxidative stress, and apoptosis signaling in RV of rats with PAH, which may be associated with an improvement in cardiac function caused by this compound.

Mitochondrial protein 18 is a positive apoptotic regulator in cardiomyocytes under oxidative stress

Accumulation of reactive oxygen species is a common phenomenon in cardiac stress conditions, for instance, coronary artery disease, aging-related cardiovascular abnormalities, and exposure to cardiac stressors such as hydrogen peroxide (H2O2). Mitochondrial protein 18 (Mtp18) is a novel mitochondrial inner membrane protein, shown to involve in the regulation of mitochondrial dynamics. Although Mtp18 is abundant in cardiac muscles, its role in cardiac apoptosis remains elusive. The present study aimed to detect the role of Mtp18 in H2O2-induced mitochondrial fission and apoptosis in cardiomyocytes. We studied the effect of Mtp18 in cardiomyocytes by modulating its expression with lentiviral construct of Mtp18-shRNA and Mtp18 c-DNA, respectively. We then analyzed mitochondrial morphological dynamics with MitoTracker Red staining; apoptosis with terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL) and cell death detection assays; and protein expression with immunoblotting. Here, we observed that Mtp18 could regulate oxidative stress- mediated mitochondrial fission and apoptosis in cardiac myocytes. Mechanistically, we found that Mtp8 induced mitochondrial fission and apoptosis by enhancing dynamin-related protein 1 (Drp1) accumulation. Conversely, knockdown of Mtp18 interfered with Drp1-associated mitochondrial fission and subsequent activation of apoptosis in both HL-1 cells and primary cardiomyocytes. However, overexpression of Mtp18 alone was not sufficient to execute apoptosis when Drp1 was minimally expressed, suggesting that Mtp18 and Drp1 are interdependent in apoptotic cascade. Together, these data highlight the role of Mtp18 in cardiac apoptosis and provide a novel therapeutic insight to minimize cardiomyocyte loss via targetting mitochondrial dynamics.

Terminalia arjuna extract and arjunic acid mitigate cobalt chloride-induced hypoxia stress-mediated apoptosis in H9c2 cells

Arjunic acid (AA) is one of the major active component of Terminalia arjuna known for its health benefits. In the present study, we evaluated cardioprotective potential of Terminalia arjuna extract (TAE) and AA against cobalt chloride (CoCl₂)-induced hypoxia damage and apoptosis in rat cardiomyocytes. TAE (50 μg/ml) and AA (8 μg/ml) significantly (p < 0.001) protected H9c2 cells as evidenced by cell viability assays against CoCl₂ (1.2 mM)-induced cytotoxicity. TAE and AA pretreatments protected the cells from oxidative damage by decreasing the generation of free radicals (ROS, hydroperoxide, and nitrite levels). TAE and AA pretreatments retained mitochondrial membrane potential by alleviating the rate of lipid peroxidation induced by CoCl₂ treatment. TAE and AA pretreatments elevated antioxidant status including phase II antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and total glutathione levels against CoCl₂-induced oxidative stress. Further immunoblotting studies confirmed anti-apoptotic effects of TAE and AA by alleviating the phosphorylation of JNK and c-jun and also by regulating protein expression levels of Bcl2, Bax, caspase 3, heat shock protein-70, and inducible nitric oxide synthase. Overall, our results suggest that both the extract and the active component exhibit antioxidant and anti-apoptotic defense against CoCl₂-induced hypoxic injury.

Notoginsenoside R1 Protects db/db Mice against Diabetic Nephropathy via Upregulation of Nrf2-Mediated HO-1 Expression

Diabetic nephropathy (DN) is a leading cause of end-stage renal failure, and no effective treatment is available. Notoginsenoside R1 (NGR1) is a novel saponin that is derived from Panax notoginseng, and our previous studies showed the cardioprotective and neuroprotective effects of NGR1. However, its role in protecting against DN remains unexplored. Herein, we established an experimental model in db/db mice and HK-2 cells exposed to advanced glycation end products (AGEs). The in vivo investigation showed that NGR1 treatment increased serum lipid, β2-microglobulin, serum creatinine, and blood urea nitrogen levels of db/db mice. NGR1 attenuated histological abnormalities of kidney, as evidenced by reducing the glomerular volume and fibrosis in diabetic kidneys. In vitro, NGR1 treatment was further found to decrease AGE-induced mitochondria injury, limit an increase in reactive oxygen species (ROS), and reduce apoptosis in HK-2 cells. Mechanistically, NGR1 promoted nucleus nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions to eliminate ROS that induced apoptosis and transforming growth factor beta (TGF-β) signaling. In summary, these observations demonstrate that NGR1 exerts renoprotective effects against DN through the inhibition of apoptosis and renal fibrosis caused by oxidative stress. NGR1 might be a potential therapeutic medicine for the treatment of DN.

Curcumin attenuates doxorubicin-induced cardiotoxicity via suppressing oxidative stress and preventing mitochondrial dysfunction mediated by 14-3-3γ

Doxorubicin (Dox) induces cardiotoxicity, thereby limiting its clinical application for chemotherapy of cancer. The mechanism of cardiotoxicity includes the production of excess intracellular ROS. 14-3-3s have been found to protect the myocardium against various types of injury. Curcumin (Cur) is a polyphenolic compound that is derived from turmeric and has multiple bioactivities, including anti-oxidative and radical-scavenging activities that exert cytoprotection. We hypothesize that the cardioprotective effects of Cur are exerted by regulating 14-3-3γ. To test the hypothesis, Dox-induced cardiotoxicity was used to establish an in vivo myocardial injury model in mice (in vivo) and primary cardiomyocytes (in intro). The effects of Cur were assessed by determining the heart rate and ECG's ST segments, as well as lactate dehydrogenase (LDH) and creatine kinase (CK) activities in the serum, caspase-3 activity, apoptosis rate, and histopathological changes of the myocardium (in vivo). In addition, cell viability, LDH, SOD, CAT, GPx, and caspase-3 activities, levels of ROS, MDA, and MMP, mPTP opening, and the apoptosis rate (in vitro) were evaluated. The expression of 14-3-3γ and Bcl-2 as well as the phosphorylation levels of Bad (S112) were determined by western blot analysis. Our results showed that Dox-induced injury to the myocardium was decreased by Cur treatment via upregulating the protein expression of 14-3-3γ in total protein and Bcl-2 expression on mitochondria, activating Bad (S112) phosphorylation, reducing the heart rate and ST segment, and reducing LDH and CK activities in the serum, thereby causing a reduction in caspase-3 activity, the apoptosis rate, and histopathological changes of the myocardium (in vivo). Furthermore, Dox treatment increased cell viability and MMP levels, decreased LDH and caspase-3 activity, ROS levels, mPTP opening, and the apoptosis rate (in vitro). However, the cardioprotective effects of Cur were attenuated by pAD/14-3-3γ-shRNA, an adenovirus that caused a knock-down of intracellular 14-3-3γ expression. In conclusion, this is the first study to demonstrate that Cur protected the myocardium against Dox-induced injury via upregulating 14-3-3γ expression, thereby promoting the translocation of Bcl-2 to mitochondria, suppressing oxidative stress, and improving mitochondrial function.

Carvedilol (CAR) combined with carnosic acid (CAA) attenuates doxorubicin-induced cardiotoxicity by suppressing excessive oxidative stress, inflammation, apoptosis and autophagy

Doxorubicin (DOX) is a wide spectrum antitumor drug. However, its clinical application is limited due to the cardiotoxicity. Carvedilol (CAR) is a β-blocker used to treat high blood pressure and heart failure. Accordingly, supplementation with natural antioxidants or plant extracts exerts protective effects against various injury in vivo. Carnosic acid (CAA), the principal constituent of rosemary, has various biological activities, including antioxidant, antitumor, and anti-inflammatory. Here, heart injury mouse model was established using DOX (20 mg/kg) in vivo. And cardiac muscle cell line of H9C2 was subjected to 0.5 μM of DOX for 24 h in vitro. Then, the protective effects of CAA and CAR alone, or the two in combination on DOX-induced cardiotoxicity in vivo and in vitro were explored. The results indicated that both CAA and CAR, when used alone, were moderately effective in attenuating DOX-induced cardiotoxicity. The combination of two drugs functioned synergistically to ameliorate cardiac injury caused by DOX, as evidenced by the significantly reduced collagen accumulation and improved dysfunction of heart. CAA and CAR exhibited stronger anti-oxidative role in DOX-treated mice partly by augmenting the expression and activities of the anti-oxidative enzymes. In addition, inflammatory response was significantly suppressed by the two in combination, proved by the decreased pro-inflammatory cytokines (COX2, TNF-α, IL-6, IL-1β and IL-18), which was associated with the inactivation of nuclear factor κB (NF-κB). Furthermore, DOX-stirred apoptosis and autophagy were dramatically attenuated by the co-treatments of CAA and CAR through down-regulating cleaved Caspase-3 and LC3B signaling pathways. The effects of CAA and CAR combination against cardiotoxicity were observed in H9C2 cells with DOX stimulation. Our findings above suggested that the use of CAR and CAA in combination could be expected to have synergistic efficacy and significant potential against cardiotoxicity induced by DOX.

Curcumin-mediated effects on anti-diabetic drug-induced cardiotoxicity

The present study was designed to compare the cardiotoxicity of two very commonly used anti-diabetic drugs namely pioglitazone (Pio) and metformin (Met); and to study the effects of curcumin (Curc) against these drug-induced cardiotoxicity. Curc, being an anti-oxidant molecule and having cardio-protective potential, can have promising synergistic effects in reducing the cardiac stress induced by anti-diabetic therapies. Various dose and time-dependent cell viability and oxidative stress assays were conducted to study cardiotoxic side-effects and Curc-mediated effects in cardiomyoblasts. Effects of Curc were also studied in hyperglycaemia induced cardiac stress in the presence of drugs. Quantitative assays for cell growth, reactive oxygen species (ROS) generation, lipid peroxidation and mitochondrial permeability followed by anti-oxidant enzymes and caspases activity assays were done to study the mechanism of action of the induced cardiotoxicity. Significant dose and time mediated deleterious effects of Pio and Met were witnessed. Oxidative stress studies showed a remarkable increase in ROS with increasing dose of anti-diabetic drugs. Increased caspase activity and altered mitochondrial integrity were also witnessed in presence of Met and Pio in cardiomyoblasts. These alterations were found to be significantly reduced when treated with Curc simultaneously. The study confirms that Met and Pio exert toxic effects on cardiac cells by generating oxidative stress. Curc, being an anti-oxidative molecule, can suppress this effect and, therefore, can be used as a supplement with anti-diabetic drugs to suppress the induced cardiac stress.

Downregulation of miR-130a, antagonized doxorubicin-induced cardiotoxicity via increasing the PPARγ expression in mESCs-derived cardiac cells

Doxorubicin (Dox) is a widely used powerful chemotherapeutic component for cancer treatment. However, its clinical application has been hampered due to doxorubicin-induced cardiomyopathy upon the cessation of chemotherapy. Previous studies revealed that PPARγ plays a crucial protective role in cardiomyocytes. Modulation of miRNA expression is an applicable approach for prohibition of toxicity induction. Therefore, the aim of present study is uprising of PPARγ transcript levels via manipulation of miRNAs to limit Dox-induced cardiotoxicity in mESCs-derived cardiac cells, as in vitro model cell to provide a simple direct approach for further clinical therapies. Based on bioinformatics data mining, eventually miR-130a was selected to target PPARγ. This miRNA is highly expressed in heart. The expression of miR-130a increases sharply upon Dox treatment while specific antagomiR-130a reverses Dox-induced reduced expression of PPARγ, cellular apoptosis, and inflammation. Our data strongly suggest that antagomiR-130a limits Dox-induced cellular toxicity via PPARγ upregulation and may have clinical relevance to limit in vivo Dox toxicity.

Curcumin in heart failure: A choice for complementary therapy?

Heart failure is a major public health concern and one of the most common reasons for a cardiac hospital admission. Heart failure may be classified as having a reduced or preserved ejection fraction and its severity is based on the symptom score. Given the aging population, it is predicted that admissions with heart failure will increase. Whilst pharmacological therapy has improved the associated morbidity and mortality, there is a need for additional therapies to improve the clinical outcome as the death rate remains high. Curcumin is a natural product derived from turmeric that appears to have cardiovascular benefit through a number of mechanisms. In this review, we have assessed the mechanisms by which curcumin may exert its effects in different models of heart failure and show that it has promise as a complementary treatment in heart failure.

NR4A2 protects cardiomyocytes against myocardial infarction injury by promoting autophagy

Myocardial infarction (MI), characterized by ischemia-induced cardiomyocyte apoptosis, is the leading cause of mortality worldwide. NR4A2, a member of the NR4A orphan nucleus receptor family, is upregulated in mouse hearts with MI injury. Furthermore, NR4A2 knockdown aggravates heart injury as evidenced by enlarged hearts and increased apoptosis. To elucidate the underlying mechanisms of NR4A2-regulated apoptosis, we used H9c2 cardiomyocytes deprived of serum and neonatal rat cardiomyocytes (NRCMs) exposed to hypoxia to mimic ischemic conditions in vivo. As NR4A2 knockdown aggravates cardiomyocyte apoptosis, while NR4A2 overexpression ameliorates it, NR4A2 upregulation was considered an adaptive response to ischemia-induced cardiomyocyte apoptosis. By detecting changes in LC3 and using autophagy detection tools including Bafilomycin A1, 3MA and rapamycin, we found that NR4A2 knockdown promoted apoptosis through blocking autophagic flux. This apoptotic response was phenocopied by downregulation of NR4A2 after autophagic flux was impaired by Bafilomycin A1. Further study showed that NR4A2 binds to p53 directly and decreases its levels when it inhibits apoptosis; thus, p53/Bax is the downstream effector of NR4A2-mediated apoptosis, as previously reported. Changes in p53/Bax that were regulated by NR4A2 were also detected in injured hearts with NR4A2 knockdown. In addition, miR-212-3p is the upstream regulator of NR4A2, and it could downregulate the expression of NR4A2, as well as p53/Bax. The mechanism underlying the role of NR4A2 in apoptosis and autophagy was elucidated, and NR4A2 may be a therapeutic drug target for heart failure.

Eupatorin and Salvigenin Potentiate Doxorubicin-Induced Apoptosis and Cell Cycle Arrest in HT-29 and SW948 Human Colon Cancer Cells

Background: Cancer persists as one of the world’s most pressing maladies. Notable points about chemotherapy are drug side effects which are almost universally encountered. Emerging knowledge focusing on mechanisms of toxicity due to chemotherapy has led to characterization of novel methods, including the exploitation of natural compounds, in combination therapies. Flavonoids are natural polyphenolic compounds that play protective roles against tumor cell development. The focus of this study was apoptotic effects of two flavonoids, eupatorin and salvigenin, in combination with doxorubicin on a cellular model of colon cancer. Method: Upon establishing a non-effective dose of doxorubicin, and effective doses of eupatorin (100μM) and salvigenin (150μM) via MTT, morphological features of apoptosis were distinguished using DAPI staining and cell cycle blockage in the sub-G1 phase. Apoptosis was determined by annexin/ PI and western blotting. ROS levels and MMP were measured to show any role of mitochondria in apoptosis. Results: Co-administration of flavonoids with doxorubicin induced apoptosis via the mitochondrial pathway as mitochondrial membrane potential and ROS production were changed. Annexin/PI analysis demonstrated that apoptosis frequency was increased with the combination treatments in colon cancer cells. Finally, the combination of these flavonoids with doxorubicin increased the Bax/Bcl-2 ratio, caspase-3 expression and PARP cleavage. Conclusion: Combination of flavonoids with doxorubicin induces apoptosis and enhances effect on cancer cells which might allow amelioration of side effects by dose lowering.

Protective effects of curcumin against doxorubicin-induced toxicity and resistance: A review

Doxorubicin (DOX)-induced toxicity and resistance are major obstacles in chemotherapeutic approaches. Despite effective in the treatment of numerous malignancies, some clinicians have voiced concern that DOX has the potential to cause debilitating consequences in organ tissues, especially the heart. The mechanisms of toxicity and resistance are respectively related to induction of reactive oxygen species (ROS) and up-regulation of ATP-binding cassette (ABC) transporter. Curcumin (CUR) with several biological and pharmacological properties is expected to restore DOX-mediated impairments to tissues. This review is intended to address the current knowledge on DOX adverse effects and CUR protective actions in the heart, kidneys, liver, brain, and reproductive organs. Coadministration of CUR and DOX is capable of ameliorating DOX toxicity pertained to antioxidant, apoptosis, autophagy, and mitochondrial permeability.

Orthogonal Array composite design to study and optimize antioxidant combinations in the prevention of UVB-induced HSF damage

Excessive exposure to ultraviolet (UV) B radiation may lead to skin damage, photosensitivity, or even tumorigenesis via induction of oxidative stress. Naturally derived antioxidants could play significant roles in cancer therapy due to their multi-targeted actions and lack of substantial toxicity. Drug combinations target at diverse pathway of cells and make cells export meticulous biological outcomes through the multifaceted signaling network. The UVB protective effects of combinations of naturally derived antioxidants- curcumin, resveratrol, proanthocyanidins, baicalein, and beta-nicotinamide adenine dinucleotide (NADH) were investigated. An oxidative cell damage model was established to study the ultraviolet irradiation system. An orthogonal array composite design (OACD) was employed in the optimization of antioxidants combinations. Combination of resveratrol (0.1μM) and baicalein in medium concentration (0.2μM), with NADH in high concentration (0.8μM) was found to be the most efficacious combination among all the 30 runs performed using OACD. The findings suggested that UVB exposure-inflicted cell apoptosis can be significantly reduced by naturally-derived antioxidant combinations. These results provide an insight into the discovery of synergistic antioxidant combinations in skin cancer, using orthogonal array composite design (OACD). The results also have practical implications in the understanding of drug mechanisms in skin cancer, which can assist clinical practice by recommending better drug combinations.