Ginsenoside Rb1 attenuates doxorubicin induced cardiotoxicity by suppressing autophagy and ferroptosis.

Ginsenoside Rb1 (Rb1), an active component isolated from traditional Chinese medicine Ginseng, is beneficial to many cardiovascular diseases. However, whether it can protect against doxorubicin induced cardiotoxicity (DIC) is not clear yet. In this study, we aimed to investigate the role of Rb1 in DIC. Mice were injected with a single dose of doxorubicin (20 mg/kg) to induce acute cardiotoxicity. Rb1 was given daily gavage to mice for 7 days. Changes in cardiac function, myocardium histopathology, oxidative stress, cardiomyocyte mitochondrion morphology were studied to evaluate Rb1's function on DIC. Meanwhile, RNA-seq analysis was performed to explore the potential underline molecular mechanism involved in Rb1's function on DIC. We found that Rb1 treatment can improve survival rate and body weight in Dox treated mice group. Rb1 can attenuate Dox induced cardiac dysfunction and myocardium hypertrophy and interstitial fibrosis. The oxidative stress increase and cardiomyocyte mitochondrion injury were improved by Rb1 treatment. Mechanism study found that Rb1's beneficial role in DIC is through suppressing of autophagy and ferroptosis. This study shown that Ginsenoside Rb1 can protect against DIC by regulating autophagy and ferroptosis.

Astragaloside IV Alleviates Doxorubicin-Induced Cardiotoxicity by Inhibiting Cardiomyocyte Pyroptosis through the SIRT1/NLRP3 Pathway.

Doxorubicin (DOX) is a powerful anthracycline antineoplastic drug used to treat a wide spectrum of tumors. However, its clinical application is limited due to cardiotoxic side effects. Astragaloside IV (AS IV), one of the major compounds present in aqueous extracts of Astragalus membranaceus, possesses potent cardiovascular protective properties, but the underlying molecular mechanisms are unclear. Thus, the aim of this study was to investigate the effect of AS IV on DOX-induced cardiotoxicity (DIC). Our findings revealed that DOX induced pyroptosis through the caspase-1/gasdermin D (GSDMD) and caspase-3/gasdermin E (GSDME) pathways. AS IV treatment significantly improved the cardiac function and alleviated myocardial injury in DOX-exposed mice by regulating intestinal flora and inhibiting pyroptosis; markedly suppressed the levels of cleaved caspase-1, N-GSDMD, cleaved caspase-3, and N-GSDME; and reversed DOX-induced downregulation of silent information regulator 1 (SIRT1) and activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome in mice. The SIRT1 inhibitor EX527 significantly blocked the protective effects of AS IV. Collectively, our results suggest that AS IV protects against DIC by inhibiting pyroptosis through the SIRT1/NLRP3 pathway.

Downregulating miRNA-199a-5p exacerbates fluorouracil-induced cardiotoxicity by activating the ATF6 signaling pathway.

BACKGROUND: Fluorouracil (5-FU) might produce serious cardiac toxic reactions. miRNA-199a-5p is a miRNA primarily expressed in myocardial cells and has a protective effect on vascular endothelium. Under hypoxia stress, the expression level of miRNA-199a-5p was significantly downregulated and is closely related to cardiovascular events such as coronary heart disease, heart failure, and hypertension. We explored whether 5-FU activates the endoplasmic reticulum stress ATF6 pathway by regulating the expression of miRNA-199a-5p in cardiac toxicity. METHODS: This project established a model of primary cardiomyocytes derived from neonatal rats and treated them with 5-FU in vitro. The expression of miRNA-199a-5p and its regulation were explored in vitro and in vivo. RESULTS: 5-FU decreases the expression of miRNA-199a-5p in cardiomyocytes, activates the endoplasmic reticulum stress ATF6 pathway, and increases the expression of GRP78 and ATF6, affecting the function of cardiomyocytes, and induces cardiac toxicity. The rescue assay further confirmed that miRNA-199a-5p supplementation can reduce the cardiotoxicity caused by 5-FU, and its protective effect on cardiomyocytes depends on the downregulation of the endoplasmic reticulum ATF6 signaling pathway. CONCLUSIONS: 5-FU can down-regulate expression of miRNA-199a-5p, then activate the endoplasmic reticulum stress ATF6 pathway, increase the expression of GRP78 and ATF6, affect the function of cardiomyocytes, and induce cardiac toxicity.

Aucubin alleviates doxorubicin-induced cardiotoxicity through crosstalk between NRF2 and HIPK2 mediating autophagy and apoptosis.

BACKGROUND: Doxorubicin (DOX) is widely used for the treatment of a variety of cancers. However, its clinical application is limited by dose-dependent cardiotoxicity. Recent findings demonstrated that autophagy inhibition and apoptosis of cardiomyocytes induced by oxidative stress dominate the pathophysiology of DOX-induced cardiotoxicity (DIC), however, there are no potential molecules targeting on these. PURPOSE: This study aimed to explore whether aucubin (AU) acting on inimitable crosstalk between NRF2 and HIPK2 mediated the autophagy, oxidative stress, and apoptosis in DIC, and provide a new and alternative strategy for the treatment of DIC. METHODS AND RESULTS: We first demonstrated the protection of AU on cardiac structure and function in DIC mice manifested by increased EF and FS values, decreased serum CK-MB and LDH contents and well-aligned cardiac tissue in HE staining. Furthermore, AU alleviated DOX-induced myocardial oxidative stress, mitochondrial damage, apoptosis, and autophagy flux dysregulation in mice, as measured by decreased ROS, 8-OHdG, and TUNEL-positive cells in myocardial tissue, increased SOD and decreased MDA in serum, aligned mitochondria with reduced vacuoles, and increased autophagosomes. In vitro, AU alleviated DOX-induced oxidative stress, autophagy inhibition, and apoptosis by promoting NRF2 and HIPK2 expression. We also identified crosstalk between NRF2 and HIPK2 in DIC as documented by overexpression of NRF2 or HIPK2 reversed cellular oxidative stress, autophagy blocking, and apoptosis aggravated by HIPK2 or NRF2 siRNA, respectively. Simultaneously, AU promoted the expression and nuclear localization of NRF2 protein, which was reversed by HIPK2 siRNA, and AU raised the expression of HIPK2 protein as well, which was reversed by NRF2 siRNA. Crucially, AU did not affect the antitumor activity of DOX against MCF-7 and HepG2 cells, which made up for the shortcomings of previous anti-DIC drugs. CONCLUSION: These collective results innovatively documented that AU regulated the unique crosstalk between NRF2 and HIPK2 to coordinate oxidative stress, autophagy, and apoptosis against DIC without compromising the anti-tumor effect of DOX in vitro.

Emodin attenuates cardiomyocyte pyroptosis in doxorubicin-induced cardiotoxicity by directly binding to GSDMD.

BACKGROUND: Doxorubicin (Dox), which is an anticancer drug, has significant cardiac toxicity and side effects. Pyroptosis occurs during Dox-induced cardiotoxicity (DIC), and drug inhibition of this process is one therapeutic approach for treating DIC. Previous studies have indicated that emodin can reduce pyroptosis. However, the role of emodin in DIC and its molecular targets remain unknown. HYPOTHESIS/PURPOSE: We aimed to clarify the protective role of emodin in mitigating DIC, as well as the mechanisms underlying this effect. METHODS: The model of DIC was established via the intraperitoneal administration of Dox at a dosage of 5 mg/kg per week for a span of 4 weeks. Emodin at two different doses (10 and 20 mg/kg) or a vehicle was intragastrically administered to the mice once per day throughout the Dox treatment period. Cardiac function, myocardial injury markers, pathological morphology of the heart, level of pyroptosis and mitochondrial function were assessed. Protein microarray, biolayer interferometry and pull-down assays were used to confirm the target of emodin. Moreover, GSDMD-overexpressing plasmids were transfected into GSDMD-/- mice and HL-1 cells to further verify whether emodin suppressed GSDMD activation. RESULTS: Emodin therapy markedly enhanced cardiac function and reduced cardiomyocyte pyroptosis in mice induced by Dox. Mechanistically, emodin binds to GSDMD and inhibits the activation of GSDMD by targeting the Trp415 and Leu290 residues. Moreover, emodin was able to mitigate Dox-induced cardiac dysfunction and myocardial injury in GSDMD-/- mice overexpressing GSDMD, as shown by increased EF and FS, decreased serum levels of CK-MB, LDH and IL-1ß and mitigated cell death and cell morphological disorder. Additionally, emodin treatment significantly reduced GSDMD-N expression and plasma membrane disruption in HL-1 cells overexpressing GSDMD induced by Dox. In addition, emodin reduced mitochondrial damage by alleviating Dox-induced GSDMD perforation in the mitochondrial membrane. CONCLUSION: Emodin has the potential to attenuate DIC by directly binding to GSDMD to inhibit pyroptosis. Emodin may become a promising drug for prevention and treatment of DIC.

A combination of isoliquiritigenin with Artemisia argyi and Ohwia caudata water extracts attenuates oxidative stress, inflammation, and apoptosis by modulating Nrf2/Ho-1 signaling pathways in SD rats with doxorubicin-induced acute cardiotoxicity.

Ohwia caudata (Thunb.) H. Ohashi (Leguminosae) also called as "Evergreen shrub" and Artemisia argyi H.Lév. and Vaniot (Compositae) also named as "Chinese mugwort" those two-leaf extracts frequently used as herbal medicine, especially in south east Asia and eastern Asia. Anthracyclines such as doxorubicin (DOX) are commonly used as effective chemotherapeutic drugs in anticancer therapy around the world. However, chemotherapy-induced cardiotoxicity, dilated cardiomyopathy, and congestive heart failure are seen in patients who receive DOX therapy, with the mechanisms underlying DOX-induced cardiac toxicity remaining unclear. Mitochondrial dysfunction, oxidative stress, inflammatory response, and cardiomyocytes have been shown to play crucial roles in DOX-induced cardiotoxicity. Isoliquiritigenin (ISL, 10 mg/kg) is a bioactive flavonoid compound with protective effects against inflammation, neurodegeneration, cancer, and diabetes. Here, in this study, our aim is to find out the Artemisia argyi (AA) and Ohwia caudata (OC) leaf extract combination with Isoliquiritigenin in potentiating and complementing effect against chemo drug side effect to ameliorate cardiac damage and improve the cardiac function. In this study, we showed that a combination of low (AA 300 mg/kg; OC 100 mg/kg) and high-dose(AA 600 mg/kg; OC 300 mg/kg) AA and OC water extract with ISL activated the cell survival-related AKT/PI3K signaling pathway in DOX-treated cardiac tissue leading to the upregulation of the antioxidant markers SOD, HO-1, and Keap-1 and regulated mitochondrial dysfunction through the Nrf2 signaling pathway. Moreover, the water extract of AA and OC with ISL inhibited the inflammatory response genes IL-6 and IL-1ß, possibly through the NFκB/AKT/PI3K/p38α/NRLP3 signaling pathways. The water extract of AA and OC with ISL could be a potential herbal drug treatment for cardiac hypertrophy, inflammatory disease, and apoptosis, which can lead to sudden heart failure.

Protective effect of vitamin B6 against doxorubicin-induced cardiotoxicity by modulating NHE1 expression.

Doxorubicin (DOX) has been used to treat various types of cancer, but its application is limited due to its heart toxicity as well as other drawbacks. Chronic inhibition of Na+ /H+ exchanger (NHE1) reduces heart failure and reduces the production of reactive oxygen species (ROS); vitamin B6 (VitB6 ) has been demonstrated to have a crucial role in antioxidant mechanism. So, this study was designed to explore the effect of VitB6 supplement on the DOX-induced cardiotoxicity and to imply whether NHE1 is involved. Ultrasonic cardiogram analysis revealed that VitB6 supplement could alleviate DOX-induced cardiotoxicity; hematoxylin and eosin (HE) and Masson's staining further confirmed this effect. Furthermore, VitB6 supplement exhibited significant antioxidative stress and antiapoptosis effect, which was evidenced by decreased serum malondialdehyde (MDA) content and increased serum superoxide dismutase (SOD) content, and decreased Bcl-2-associated X protein/B-cell lymphoma-2 ratio, respectively. Collectively, VitB6 supplement may exert antioxidative and antiapoptosis effects to improve cardiac function by decreasing NHE1 expression and improve DOX-induced cardiotoxicity.

Amentoflavone mitigates doxorubicin-induced cardiotoxicity by suppressing cardiomyocyte pyroptosis and inflammation through inhibition of the STING/NLRP3 signalling pathway.

BACKGROUND: Doxorubicin (DOX) is a potent anticancer chemotherapeutic agent whose clinical application is substantially constrained by its cardiotoxicity. The pathophysiology of DOX-induced cardiotoxicity manifests as cardiomyocyte pyroptosis and inflammation. Amentoflavone (AMF) is a naturally occurring biflavone possessing anti-pyroptotic and anti-inflammatory properties. However, the mechanism through which AMF alleviates DOX-induced cardiotoxicity remains undetermined. PURPOSE: This study aimed at investigating the role of AMF in alleviating DOX-induced cardiotoxicity. STUDY DESIGN AND METHODS: To assess the in vivo effect of AMF, DOX was intraperitoneally administered into a mouse model to induce cardiotoxicity. To elucidate the underlying mechanisms, the activities of STING/NLRP3 were quantified using the NLRP3 agonist nigericin and the STING agonist amidobenzimidazole (ABZI). Primary cardiomyocytes isolated from neonatal Sprague-Dawley rats were treated with saline (vehicle) or DOX with or without AMF and/or ABZI. The echocardiogram, haemodynamics, cardiac injury markers, heart/body weight ratio, and pathological alterations were monitored; the STING/NLRP3 pathway-associated proteins were detected by western blot and cardiomyocyte pyroptosis was analysed by immunofluorescence staining of cleaved N-terminal GSDMD and scanning electron microscopy. Furthermore, we evaluated the potential of AMF in compromising the anticancer effects of DOX in human breast cancer cell lines. RESULTS: AMF substantially alleviated cardiac dysfunction and reduced heart/body weight ratio and myocardial damage in mice models of DOX-induced cardiotoxicity. AMF effectively suppressed DOX-mediated upregulation of IL-1ß, IL-18, TNF-α, and pyroptosis-related proteins, including NLRP3, cleaved caspase-1, and cleaved N-terminal GSDMD. The levels of apoptosis-related proteins, namely Bax, cleaved caspase-3, and BCL-2 were not affected. In addition, AMF inhibited STING phosphorylation in DOX-affected hearts. Intriguingly, the administration of nigericin or ABZI dampened the cardioprotective effects of AMF. The in vitro anti-pyroptotic effect of AMF was demonstrated in attenuating the DOX-induced reduction in cardiomyocyte cell viability, upregulation of cleaved N-terminal GSDMD, and pyroptotic morphology alteration at the microstructural level. AMF exhibited a synergistic effect with DOX to reduce the viability of human breast cancer cells. CONCLUSION: AMF alleviates DOX-induced cardiotoxicity by suppressing cardiomyocyte pyroptosis and inflammation via inhibition of the STING/NLRP3 signalling pathway, thereby validating its efficacy as a cardioprotective agent.

AKR1B1 inhibition using NARI-29-an Epalrestat analogue-alleviates Doxorubicin-induced cardiotoxicity via modulating Calcium/CaMKII/MuRF-1 axis.

The clinical use of doxorubicin (Dox) is narrowed due to its carbonyl reduction to doxorubicinol (Doxol) implicating resistance and cardiotoxicity. Hence, in the present study we have evaluated the cardioprotective effect of AKR1B1 (or aldose reductase, AR) inhibitor NARI-29 (epalrestat (EPS) analogue) and its effect in the Dox-modulated calcium/CaMKII/MuRF1 axis. Initially, the breast cancer patient survival associated with AKR1B1 expression was calculated using Kaplan Meier-plotter (KM-plotter). Further, breast cancer, cardiomyoblast (H9c2), and macrophage (RAW 264.7) cell lines were used to establish the in vitro combination effect of NARI-29 and Dox. To develop the cardiotoxicity model, mice were given Dox 2.5 mg/kg (i.p.), biweekly. The effect of AKR1B1 inhibition using NARI-29 on molecular and cardiac functional changes was measured using echocardiography, fluorescence-imaging, ELISA, immunoblotting, flowcytometry, High-Performance Liquid Chromatography with Fluorescence Detection (HPLC-FD) and cytokine-bead array methods. The bioinformatics data suggested that a high expression of AKR1B1 is associated with significantly low survival of breast cancer patients undergoing chemotherapy; hence, it could be a target for chemo-sensitization and chemo-prevention. Further, in vitro studies showed that AKR1B1 inhibition with NARI-29 has increased the accumulation and sensitized Dox to breast cancer cell lines. However, treatment with NARI-29 has alleviated the Dox-induced toxicity to cardiomyocytes and decreased the secretion of inflammatory cytokines from RAW 264.7 cells. In vivo studies revealed that the NARI-29 (25 and 50 mg/kg) has prevented the functional, histological, biochemical, and molecular alterations induced by Dox treatment. Moreover, we have shown that NARI-29 has prevented the carbonyl reduction of Dox to Doxol in the mouse heart, which reduced the calcium overload, prevented phosphorylation of CaMKII, and reduced the expression of MuRF1 to protect from cardiac injury and apoptosis. Hence in conclusion, AKR1B1 inhibitor NARI-29 could be used as an adjuvant therapeutic agent with Dox to prevent cardiotoxicity and synergize anti-breast cancer activity.

Extract of Platycodon grandiflorum Prevents Doxorubicin-induced Cardiotoxicity in Breast Cancer.

Doxorubicin (Dox) is a first-line chemotherapeutic agent applied in cancer treatment. Its long-term anticancer efficacy is restricted mainly due to its subsequent cardiotoxicity for patients. Platycodon grandiflorum (PG), an important traditional Chinese herb, has been reported to eliminate phlegm, relieve cough, and reduce inflammatory diseases. Previous clinical studies found that PG has cardioprotective effects for early breast cancer patients who received Dox-based chemotherapy. However, the cellular and molecular mechanisms underlying PG-mediated cardiotoxic rescue remain elusive. This study aimed to explore the protective role and potential molecular mechanisms of PG on Dox-induced cardiac dysfunction in a mouse model of breast cancer. PG significantly alleviated myocardial damage and prevented cardiomyocyte apoptosis induced by Dox. The expression levels of cytochrome C and cleaved caspase-3 significantly decreased, and the levels of Bcl-XL and B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated X protein increased following PG treatment. Furthermore, PG remarkably enhanced the antimetastatic efficacy (versus the Dox group) by regulating the balance of matrix metalloproteinases/tissue inhibitors of metalloproteinases.

Selenium alleviates endoplasmic reticulum calcium depletion-induced endoplasmic reticulum stress and apoptosis in chicken myocardium after mercuric chloride exposure.

Mercury is a highly toxic heavy metal with definite cardiotoxic properties and can affect the health of humans and animals through diet. Selenium (Se) is a heart-healthy trace element and dietary Se has the potential to attenuate heavy metal-induced myocardial damage in humans and animals. This study was designed to explore antagonistic effect of Se on the cardiotoxicity of mercuric chloride (HgCl2) in chickens. Hyline brown hens received a normal diet, a diet containing 250 mg/L HgCl2, or a diet containing 250 mg/L HgCl2 and 10 mg/kg Na2SeO3 for 7 weeks, respectively. Histopathological observations demonstrated that Se attenuated HgCl2-induced myocardial injury, which was further confirmed by the results of serum creatine kinase and lactate dehydrogenase levels assay and myocardial tissues oxidative stress indexes assessment. The results showed that Se prevented HgCl2-induced cytoplasmic calcium ion (Ca2+) overload and endoplasmic reticulum (ER) Ca2+ depletion mediated by Ca2+-regulatory dysfunction of ER. Importantly, ER Ca2+ depletion led to unfolded protein response and endoplasmic reticulum stress (ERS), resulting in apoptosis of cardiomyocytes via PERK/ATF4/CHOP pathway. In addition, heat shock protein expression was activated by HgCl2 through these stress responses, which was reversed by Se. Moreover, Se supplementation partially eliminated the effects of HgCl2 on the expression of several ER-settled selenoproteins, including selenoprotein K (SELENOK), SELENOM, SELENON, and SELENOS. In conclusion, these results suggested that Se alleviated ER Ca2+ depletion and oxidative stress-induced ERS-dependent apoptosis in chicken myocardium after HgCl2 exposure.

Lycopene prevents Di-(2-ethylhexyl) phthalate-induced mitophagy and oxidative stress in mice heart via modulating mitochondrial homeostasis.

Di-(2-ethylhexyl) phthalate (DEHP) is a plasticizer that is easily found in the environment. Excessive daily exposure of it may lead to an increased risk of cardiovascular disease (CVD). Lycopene (LYC), as a natural carotenoid, has been shown to have the potential to prevent CVD. However, the mechanism of LYC on cardiotoxicity caused by DEHP exposure is unknown. The research was aimed to investigate the chemoprotection of LYC on the cardiotoxicity caused by DEHP exposure. Mice were treated with DEHP (500 mg/kg or 1,000 mg/kg) and/or LYC (5 mg/kg) for 28 d by intragastric administration, and the heart was subjected to histopathology and biochemistry analysis. The results indicated that DEHP caused cardiac histological alterations and enhanced the activity of cardiac injury indicators, and interfered with mitochondrial function and activating mitophagy. Notably, LYC supplementation could inhibit DEHP-induced oxidative stress. The mitochondrial dysfunction and emotional disorder caused by DEHP exposure were significantly improved through the protective effect of LYC. We concluded that LYC enhances mitochondrial function by regulating mitochondrial biogenesis and dynamics to antagonize DEHP-induced cardiac mitophagy and oxidative stress.

Fluorescent hiPSC-derived MYH6-mScarlet cardiomyocytes for real-time tracking, imaging, and cardiotoxicity assays.

Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) hold great potential in the cardiovascular field for human disease modeling, drug development, and regenerative medicine. However, multiple hurdles still exist for the effective utilization of hiPSC-CMs as a human-based experimental platform that can be an alternative to the current animal models. To further expand their potential as a research tool and bridge the translational gap, we have generated a cardiac-specific hiPSC reporter line that differentiates into fluorescent CMs using CRISPR-Cas9 genome editing technology. The CMs illuminated with the mScarlet fluorescence enable their non-invasive continuous tracking and functional cellular phenotyping, offering a real-time 2D/3D imaging platform. Utilizing the reporter CMs, we developed an imaging-based cardiotoxicity screening system that can monitor distinct drug-induced structural toxicity and CM viability in real time. The reporter fluorescence enabled visualization of sarcomeric disarray and displayed a drug dose-dependent decrease in its fluorescence. The study also has demonstrated the reporter CMs as a biomaterial cytocompatibility analysis tool that can monitor dynamic cell behavior and maturity of hiPSC-CMs cultured in various biomaterial scaffolds. This versatile cardiac imaging tool that enables real time tracking and high-resolution imaging of CMs has significant potential in disease modeling, drug screening, and toxicology testing.

Activation of p62-NRF2 Axis Protects against Doxorubicin-Induced Ferroptosis in Cardiomyocytes: A Novel Role and Molecular Mechanism of Resveratrol.

Doxorubicin (DOX) is a most common anthracycline chemotherapeutic agent; however, its clinical efficacy is limited due to its severe and irreversible cardiotoxicity. Ferroptosis, characterized by iron overload and lipid peroxidation, plays a pivotal role in DOX-induced cardiotoxicity. Resveratrol (RSV) displays cardioprotective and anticancer effects, owing to its antioxidative and anti-inflammatory properties. However, the role and mechanism of RSV in DOX-mediated ferroptosis in cardiomyocytes is unclear. This study showed that DOX decreased cell viability, increased iron accumulation and lipid peroxidation in H9c2 cells; however, these effects were reversed by RSV and ferroptosis inhibitor ferrostatin-1 (Fer-1) pre-treatment. Additionally, RSV significantly increased the cell viability of H9c2 cells treated with ferroptosis inducers Erastin (Era) and RSL3. Mechanistically, RSV inhibited mitochondrial reactive oxygen species (mtROS) overproduction and upregulated the p62-NRF2/HO-1 pathway. RSV-induced NRF2 activation was partially dependent on p62, and the selective inhibition of p62 (using p62-siRNA interference) or NRF2 (using NRF2 specific inhibitor, ML385) significantly abolished the anti-ferroptosis function of RSV. Furthermore, RSV treatment protected mice against DOX-induced cardiotoxicity, including significantly improving left ventricular function, ameliorating myocardial fibrosis and suppressing ferroptosis. Consistent with in vitro results, RSV also upregulated the p62-NRF2/HO-1 expression, which was inhibited by DOX, in the myocardium. Notably, the protective effect of RSV in DOX-mediated ferroptosis was similar to that of Fer-1 in vitro and in vivo. Thus, the p62-NRF2 axis plays a critical role in regulating DOX-induced ferroptosis in cardiomyocytes. RSV as a potent p62 activator has potential as a therapeutic target in preventing DOX-induced cardiotoxicity via ferroptosis modulation.

Mechanisms and Drug Intervention for Doxorubicin-Induced Cardiotoxicity Based on Mitochondrial Bioenergetics.

Doxorubicin (DOX) is an anthracycline chemotherapy drug, which is indispensable in antitumor therapy. However, its subsequent induction of cardiovascular disease (CVD) has become the primary cause of mortality in cancer survivors. Accumulating evidence has demonstrated that cardiac mitochondrial bioenergetics changes have become a significant marker for doxorubicin-induced cardiotoxicity (DIC). Here, we mainly summarize the related mechanisms of DOX-induced cardiac mitochondrial bioenergetics disorders reported in recent years, including mitochondrial substrate metabolism, the mitochondrial respiratory chain, myocardial ATP storage and utilization, and other mechanisms affecting mitochondrial bioenergetics. In addition, intervention for DOX-induced cardiac mitochondrial bioenergetics disorders using chemical drugs and traditional herbal medicine is also summarized, which will provide a comprehensive process to study and develop more appropriate therapeutic strategies for DIC.

Natural compound glycyrrhetinic acid protects against doxorubicin-induced cardiotoxicity by activating the Nrf2/HO-1 signaling pathway.

BACKGROUND: As one of the most classic antineoplastic agents, doxorubicin (Dox) is extensively used to treat a wide range of cancers. Nevertheless, the clinical outcomes of Dox-based therapies are severely hampered due to the significant cardiotoxicity. Glycyrrhetinic acid (GA) is the major biologically active compound of licorice, one of the most well-known food additives and medicinal plants in the world. We previously demonstrated that GA has the potential capability to protect mice from Dox-induced cardiac injuries. However, the underlying cardioprotective mechanism remains unexplored. PURPOSE: To investigate the cardioprotective benefits of GA against Dox-induced cardiotoxicity and to elucidate its mechanisms of action. STUDY DESIGN/METHODS: H9c2 cardiomyoblasts and AC16 cardiomyocytes were used as the cell models in vitro. A transgenic zebrafish model and a 4T1 mouse breast cancer model were applied to explore the cardioprotective effects of GA in vivo. RESULTS: In vitro, GA inhibited Dox-induced cell death and LDH release in H9c2 and AC16 cells without affecting the anti-cancer effects of Dox. GA significantly alleviated Dox-induced ROS generation, mitochondrial dysfunction, and apoptosis in H9c2 cells. Moreover, GA abolished the expression of pro-apoptotic proteins and restored Nrf2/HO-1 signaling pathway in Dox-treated H9c2 cells. On the contrary, Nrf2 knockdown strongly abrogated the cardioprotective effects of GA on Dox-treated H9c2 cells. In vivo, GA attenuated Dox-induced cardiac dysfunction by restoring stroke volume, cardiac output, and fractional shortening in the transgenic zebrafish embryos. In a 4T1 mouse breast cancer model, GA dramatically prevented body weight loss, attenuated cardiac dysfunction, and prolonged survival rate in Dox-treated mice, without compromising Dox's anti-tumor efficacy. Consistently, GA attenuated oxidative injury, reduced cardiomyocytes apoptosis, and restored the expressions of Nrf2 and HO-1 in Dox-treated mouse hearts. CONCLUSION: GA protects against Dox-induced cardiotoxicity by suppressing oxidative stress, mitochondrial dysfunction, and apoptosis via upregulating Nrf2/HO-1 signaling pathway. These findings could provide solid evidence to support the further development of GA as a feasible and safe adjuvant to Dox chemotherapy for overcoming Dox-induced cardiotoxicity.

Tanshinone I inhibits doxorubicin-induced cardiotoxicity by regulating Nrf2 signaling pathway.

BACKGROUND: Doxorubicin (DOX) is a powerful anti-tumor anthracycline drug. However, its clinical use is limited due to the side effect of cardiotoxicity. Tanshinone I (Tan I) is one of the major tanshinones isolated from Salvia miltiorrhiza. Studies have shown that Tan I is effective in the treatment of cardiovascular diseases. However, the potential effects of Tan I against DOX-induced cardiotoxicity (DIC) have yet to be explored. PURPOSE: This study aimed to explore whether Tan I can protect against DIC and to reveal whether Tan I can exert anti-oxidative effect by regulating nuclear erythroid factor 2-related factor 2 (Nrf2) pathway. METHODS: DIC models were established in vivo by intravenous injection of DOX. Echocardiography was used to monitor the cardiac function of mice. Transmission electron microscopy was used to assess mitochondrial damage. Oxidative stress was measured by dihydroethidium (DHE) staining and western blotting. The accumulation and nuclear translocation of Nrf2 was detected by immunofluorescence. H9C2 cellular DIC model was established in vitro to explore the pharmacological mechanism. Nrf2 small interfering (si)-RNA was applied to H9C2 cells to explore whether Tan I exerted protective effect against DIC through Nrf2 signaling pathway. The protective effects of Tan I on mitochondrial function and mitochondrial membrane permeability were measured by MitoSOX™ Red and JC-1 staining assays, respectively. RESULTS: In vivo experiments revealed that Tan I could improve cardiac function and protect against DOX-induced myocardial structural damages in mice models. The oxidative stress induced by DOX was suppressed and apoptosis was mitigated by Tan I treatment. Tan I protected against DOX-induced mitochondrial structural damage. Meanwhile, key proteins in Nrf2 pathways were upregulated by Tan I treatment. In vitro studies showed that Tan I attenuated DOX-induced generation of reactive oxygen species (ROS) in cultured H9C2 cells, reduced apoptotic rates, protected mitochondrial functions and up-regulated Nrf2 signaling pathway. Tan I promoted accumulation and nuclear translocation of Nrf2 protein. In addition, interference of Nrf2 abrogated the anti-oxidative effects of Tan I and reversed the expressions of key proteins in Nrf2 pathway. The protective effects of Tan I on mitochondrial integrity was also mitigated by Nrf2 interference. CONCLUSION: Tan I could reduce oxidative stress and protect against DIC through regulating Nrf2 signaling pathway. Nrf2 is a potential target and Tan I is a novel candidate agent for the treatment of DIC.

Aidi injection reduces doxorubicin-induced cardiotoxicity by inhibiting carbonyl reductase 1 expression.

CONTEXT: Aidi injection (ADI), a traditional Chinese medicine antitumor injection, is usually combined with doxorubicin (DOX) for the treatment of malignant tumours. The cardiotoxicity of DOX is ameliorated by ADI in the clinic. However, the relevant mechanism is unknown. OBJECTIVE: To investigate the effects of ADI on DOX-induced cardiotoxicity and its mechanism. MATERIALS AND METHODS: ICR mice were randomly divided into six groups: control, ADI-L, ADI-H, DOX, DOX + ADI-L and DOX + ADI-H. DOX (i.p., 0.03 mg/10 g) was administered in the presence or absence of ADI (i.p., 0.1 or 0.2 mL/10 g) for two weeks. Heart pathology and levels of AST, LDH, CK, CK-MB and BNP were assessed. H9c2 cells were treated with DOX in the presence or absence of ADI (1, 4, 10%). Cell viability, caspase-3 activity, nuclear morphology, and CBR1 expression were then evaluated. DOX and doxorubicinol (DOXol) concentrations in heart, liver, kidneys, serum, and cells were analysed by UPLC-MS/MS. RESULTS: High-dose ADI significantly reduced DOX-induced pathological changes and the levels of AST, LDH, CK, CK-MB and BNP to normal. Combined treatment with ADI (1, 4, 10%) improved the cell viability, and IC50 increased from 68.51 µM (DOX alone) to 83.47, 176.9, and 310.8 µM, reduced caspase-3 activity by 39.17, 43.96, and 61.82%, respectively. High-dose ADI inhibited the expression of CBR1 protein by 32.3%, reduced DOXol levels in heart, serum and H9c2 cells by 59.8, 72.5 and 48.99%, respectively. DISCUSSION AND CONCLUSIONS: ADI reduces DOX-induced cardiotoxicity by inhibiting CBR1 expression, which provides a scientific basis for the rational use of ADI.

An in silico-in vitro pipeline for drug cardiotoxicity screening identifies ionic pro-arrhythmia mechanisms.

BACKGROUND AND PURPOSE: Before advancing to clinical trials, new drugs are screened for their pro-arrhythmic potential using a method that is overly conservative and provides limited mechanistic insight. The shortcomings of this approach can lead to the mis-classification of beneficial drugs as pro-arrhythmic. EXPERIMENTAL APPROACH: An in silico-in vitro pipeline was developed to circumvent these shortcomings. A computational human induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM) model was used as part of a genetic algorithm to design experiments, specifically electrophysiological voltage clamp (VC) protocols, to identify which of several cardiac ion channels were blocked during in vitro drug studies. Such VC data, along with dynamically clamped action potentials (AP), were acquired from iPSC-CMs before and after treatment with a control solution or a low- (verapamil), intermediate- (cisapride or quinine) or high-risk (quinidine) drug. KEY RESULTS: Significant AP prolongation (a pro-arrhythmia marker) was seen in response to quinidine and quinine. The VC protocol identified block of IKr (a source of arrhythmias) by all strong IKr blockers, including cisapride, quinidine and quinine. The protocol also detected block of ICaL by verapamil and Ito by quinidine. Further demonstrating the power of the approach, the VC data uncovered a previously unidentified If block by quinine, which was confirmed with experiments using a HEK-293 expression system and automated patch-clamp. CONCLUSION AND IMPLICATIONS: We developed an in silico-in vitro pipeline that simultaneously identifies pro-arrhythmia risk and mechanism of ion channel-blocking drugs. The approach offers a new tool for evaluating cardiotoxicity during preclinical drug screening.

Quercetin Mitigates Cisplatin-Induced Oxidative Damage and Apoptosis in Cardiomyocytes through Nrf2/HO-1 Signaling Pathway.

Cisplatin is massively used to treat solid tumors. However, several severe adverse effects, such as cardiotoxicity, are obstacles to its clinical application. Cardiotoxicity may lead to congestive heart failure and even sudden cardiac death in patients receiving cisplatin. Therefore, finding a novel therapeutic strategy for the prevention of cisplatin-induced cardiotoxicity is urgent. Quercetin is a flavonol compound that can be found in dietary fruits and vegetables. The antioxidant function and anti-inflammatory capacity of quercetin have been reported. However, whether quercetin could protect against cisplatin-caused apoptosis and cellular damage in cardiomyocytes is still unclear. H9c2 cardiomyocytes were treated with cisplatin (40 µM) for 24 h to induce cellular damage with or without quercetin pretreatment. We found that quercetin activates Nrf2 and HO-1 expression, thereby mitigating cisplatin-caused cytotoxicity in H9c2 cells. Quercetin also increases SOD levels, maintains mitochondrial function, and reduces oxidative stress under cisplatin stimulation. Quercetin attenuates cisplatin-induced apoptosis and inflammation in H9c2 cardiomyocytes; however, these cytoprotective effects were diminished by silencing Nrf2 and HO-1. In conclusion, this study reports that quercetin has the potential to antagonize cisplatin-caused cardiotoxicity by reducing ROS-mediated mitochondrial damage and inflammation via the Nrf2/HO-1 and p38MAPK/NF-[Formula: see text]Bp65/IL-8 signaling pathway. This study provided the theoretical basis and experimental proof for the clinical application of quercetin as a new effective strategy to relieve chemotherapy-induced cardiotoxicity.