β-LAPachone ameliorates doxorubicin-induced cardiotoxicity via regulating autophagy and Nrf2 signalling pathways in mice

The Role of mTOR in the Doxorubicin-Induced Cardiotoxicity: A Systematic Review

Doxorubicin (DOX) is a chemotherapy drug known to induce metabolic changes in the heart, leading to potential heart toxicity. These changes impact various cellular functions and pathways such as disrupting the mechanistic target of rapamycin (mTOR) signaling pathway. The study aimed to investigate the effect of DOX on the mTOR pathway through an in vivo systematic review. Databases were searched on September 11, 2023. We finally included 30 in vivo studies that examined the mTOR expression in cardiac tissue samples. The present study has shown that the PI3K/AKT/mTOR, the AMPK/mTOR, the p53/mTOR signaling, the mTOR/TFEB pathway, the p38 MAPK/mTOR, the sestrins/mTOR, and the KLF15/eNOS/mTORC1 signaling pathways play a crucial role in the development of DOX-induced cardiotoxicity. Inhibition or dysregulation of these pathways can lead to increased oxidative stress, apoptosis, and other adverse effects on the heart. Strategies that target and modulate the mTOR pathways, such as the use of mTOR inhibitors like rapamycin, have the potential to enhance the anticancer effects of DOX while also mitigating its cardiotoxic side effects.

Research progress on the role and mechanism of Sirtuin family in doxorubicin cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a widely utilized anthracycline chemotherapy drug in cancer treatment, yet its efficacy is hindered by both short-term and long-term cardiotoxicity. Although oxidative stress, inflammation and mitochondrial dysfunction are established factors in DOX-induced cardiotoxicity, the precise molecular pathways remain elusive. Further exploration of the pathogenesis and identification of novel molecular targets are imperative. Recent studies have implicated the Sirtuins family in various physiological and pathological processes, suggesting their potential in ameliorating DOX-induced cardiotoxicity. Moreover, research on Sirtuins has discovered small-molecule compounds or medicinal plants with regulatory effects, representing a notable advancement in preventing and treating DOX-induced cardiac injury.

PURPOSE

In this review, we delve into the pathogenesis of DOX-induced cardiotoxicity and explore the therapeutic effects of Sirtuins in mitigating this condition, along with the associated molecular mechanisms. Furthermore, we delineate the roles and mechanisms of small-molecule regulators of Sirtuins in the prevention and treatment of DOX-induced cardiotoxicity.

STUDY-DESIGN/METHODS

Data for this review were sourced from various scientific databases (such as Web of Science, PubMed and Science Direct) up to March 2024. Search terms included "Sirtuins," "DOX-induced cardiotoxicity," "DOX," "Sirtuins regulators," "histone deacetylation," among others, as well as several combinations thereof.

RESULTS

Members of the Sirtuins family regulate both the onset and progression of DOX-induced cardiotoxicity through anti-inflammatory, antioxidative stress and anti-apoptotic mechanisms, as well as by maintaining mitochondrial stability. Moreover, natural plant-derived active compounds such as Resveratrol (RES), curcumin, berberine, along with synthetic small-molecule compounds like EX527, modulate the expression and activity of Sirtuins.

CONCLUSION

The therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity represents a potential molecular target. However, further research is urgently needed to elucidate the relevant molecular mechanisms and to assess the safety and biological activity of Sirtuins regulators. This review offers an in-depth understanding of the therapeutic role of the Sirtuins family in mitigating DOX-induced cardiotoxicity, providing a preliminary basis for the clinical application of Sirtuins regulators in this condition.

The Role of mTOR in Doxorubicin-Altered Cardiac Metabolism: A Promising Therapeutic Target of Natural Compounds

Doxorubicin (DOX) is commonly used for the treatment of various types of cancer, however can cause serious side effects, including cardiotoxicity. The mechanisms involved in DOX-induced cardiac damage are complex and not yet fully understood. One mechanism is the disruption of cardiac metabolism, which can impair cardiac function. The mammalian target of rapamycin (mTOR) is a key regulator of cardiac energy metabolism, and dysregulation of mTOR signaling has been implicated in DOX-induced cardiac dysfunction. Natural compounds (NCs) have been shown to improve cardiac function in vivo and in vitro models of DOX-induced cardiotoxicity. This review article explores the protective effects of NCs against DOX-induced cardiac injury, with a focus on their regulation of mTOR signaling pathways. Generally, the modulation of mTOR signaling by NCs represents a promising strategy for decreasing the cardiotoxic effects of DOX.

β-lapachone protects against doxorubicin-induced hepatotoxicity through modulation of NAD+ /SIRT-1/FXR/p-AMPK/NF-kB and Nrf2 signaling axis

Doxorubicin (DOX) is a widely used antineoplastic drug, but its clinical use is limited by significant toxicities, such as hepatotoxicity. In this study, we evaluated the effects of β-lapachone (β-LAP), a natural quinone-containing compound, in a mouse model of DOX-induced hepatotoxicity. β-LAP was orally administered at 1.25, 2.5, and 5 mg/kg for 4 days, and a single dose of DOX (20 mg/kg) was injected intraperitoneally on the second day. Histopathological changes, liver function markers, antioxidant and inflammatory markers were assessed. β-LAP ameliorated liver injury and liver function markers evoked by DOX. β-LAP also downregulated the mRNA expression of nuclear factor-kB-corresponding genes including interleukin-6, interleukin-1β, and tumor necrosis factor-α. Moreover, β-LAP increased the nuclear factor erythroid 2-related factor 2 target genes heme oxygenase-1 and NAD(P)H: quinone oxidoreductase 1, along with antioxidant enzymes including reduced glutathione, catalase, and superoxide dismutase with simultaneous reduction in the lipid peroxidation product malondialdehyde. Meanwhile, it recovered NAD+ /NADH ratios and subsequently elevated the protein levels of sirtuin-1 (SIRT-1), farnesoid X receptor (FXR), and phosphorylated AMP-activated protein kinase (p-AMPK). Collectively, these findings suggest a protective role of β-LAP against DOX-induced hepatotoxicity by partly regulating the NAD+ /SIRT-1/FXR/p-AMPK axis.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

Water Extract of Capsella bursa-pastoris Mitigates Doxorubicin-Induced Cardiotoxicity by Upregulating Antioxidant Enzymes

Doxorubicin (DOX), an effective chemotherapeutic drug, causes cardiotoxicity in a cumulative and dose-dependent manner. The aim of this study is to investigate the effects of hot-water extract of Capsella bursa-pastoris (CBW) on DOX-induced cardiotoxicity (DICT). We utilized H9c2 rat cardiomyocytes and MDA-MB-231 human breast cancer cells to evaluate the effects of CBW on DOX-induced cell death. Superoxide dismutase (SOD) levels, reactive oxygen species (ROS) production, and oxygen consumption rate were measured in H9c2 cells. C57BL/6 mice were treated with DOX and CBW to assess their impact on various cardiac parameters. Human-induced pluripotent stem-cell-derived cardiomyocytes were also used to investigate DOX-induced electrophysiological changes and the potential ameliorative effects of CBW. UPLC-TQ/MS analysis identified seven flavonoids in CBW, with luteolin-7-O-glucoside and isoorientin as the major compounds. CBW inhibited DOX-induced death of H9c2 rat cardiomyocytes but did not affect DOX-induced death of MDA-MB-231 human breast cancer cells. CBW increased SOD levels in a dose-dependent manner, reducing ROS production and increasing the oxygen consumption rate in H9c2 cells. The heart rate, RR interval, QT, and ST prolongation remarkably recovered in C57BL/6 mice treated with the combination of DOX and CBW compared to those in mice treated with DOX alone. Administration of CBW with DOX effectively alleviated collagen accumulation, cell death in mouse heart tissues, and reduced the levels of creatinine kinase (CK) and lactate dehydrogenase (LDH) in serum. Furthermore, DOX-induced pathological electrophysiological features in human-induced pluripotent stem-cell-derived cardiomyocytes were ameliorated by CBW. CBW may prevent DICT by stabilizing SOD and scavenging ROS. The presence of flavonoids, particularly luteolin-7-O-glucoside and isoorientin, in CBW may contribute to its protective effects. These results suggest the potential of CBW as a traditional therapeutic option to mitigate DOX-induced cardiotoxicity.

Nrf2: a dark horse in doxorubicin-induced cardiotoxicity

Being a broad-spectrum anticancer drug, doxorubicin is indispensable for clinical treatment. Unexpectedly, its cardiotoxic side effects have proven to be a formidable obstacle. Numerous studies are currently devoted to elucidating the pathological mechanisms underlying doxorubicin-induced cardiotoxicity. Nrf2 has always played a crucial role in oxidative stress, but numerous studies have demonstrated that it also plays a vital part in pathological mechanisms like cell death and inflammation. Numerous studies on the pathological mechanisms associated with doxorubicin-induced cardiotoxicity demonstrate this. Several clinical drugs, natural and synthetic compounds, as well as small molecule RNAs have been demonstrated to prevent doxorubicin-induced cardiotoxicity by activating Nrf2. Consequently, this study emphasizes the introduction of Nrf2, discusses the role of Nrf2 in doxorubicin-induced cardiotoxicity, and concludes with a summary of the therapeutic modalities targeting Nrf2 to ameliorate doxorubicin-induced cardiotoxicity, highlighting the potential value of Nrf2 in doxorubicin-induced cardiotoxicity.

Therapeutic application of natural products: NAD+ metabolism as potential target

BACKGROUND

Nicotinamide adenine dinucleotide (NAD⁺) metabolism is involved in the entire physiopathological process and is critical to human health. Long-term imbalance in NAD⁺ homeostasis is associated with various diseases, including non-alcoholic fatty liver disease, diabetes mellitus, cardiovascular diseases, neurodegenerative disorders, aging, and cancer, making it a potential target for effective therapeutic strategies. Currently, several natural products that target NAD⁺ metabolism have been widely reported to have significant therapeutic effects, but systematic summaries are lacking.

PURPOSE

To summarize the latest findings on the prevention and treatment of various diseases through the regulation of NAD⁺ metabolism by various natural products in vivo and in vitro models, and evaluate the toxicities of the natural products.

METHODS

PubMed, Web of Science, and ScienceDirect were searched using the keywords "natural products sources," "toxicology," "NAD⁺ clinical trials," and "NAD⁺," and/or paired with "natural products" and "diseases" for studies published within the last decade until January 2023.

RESULTS

We found that the natural products mainly include phenols (curcumin, cyclocurcumin, 4-hydroxybenzyl alcohol, salvianolic acid B, pterostilbene, EGCG), flavonoids (pinostrobin, apigenin, acacetin, tilianin, kaempferol, quercetin, isoliquiritigenin, luteolin, silybin, hydroxysafflor yellow A, scutellarin), glycosides (salidroside), quinones (emodin, embelin, β-LAPachone, shikonin), terpenoids (notoginsenoside R1, ginsenoside F2, ginsenoside Rd, ginsenoside Rb1, ginsenoside Rg3, thymoquinone, genipin), pyrazines (tetramethylpyrazine), alkaloids (evodiamine, berberine), and phenylpropanoids (ferulic acid). These natural products have antioxidant, energy-producing, anti-inflammatory, anti-apoptotic and anti-aging effects, which mainly influence the NAMPT/NAD⁺/SIRT, AMPK/SIRT1/PGC-1α, Nrf2/HO-1, PKCs/PARPs/NF-κB, and AMPK/Nrf2/mTOR signaling pathways, thereby regulating NAD⁺ metabolism to prevent and treat various diseases. These natural products have been shown to be safe, tolerable and have fewer adverse effects in various in vivo and in vitro studies and clinical trials.

CONCLUSION

We evaluated the toxic effects of natural products and summarized the available clinical trials on NAD⁺ metabolism, as well as the recent advances in the therapeutic application of natural products targeting NAD⁺ metabolism, with the aim to provide new insights into the treatment of multiple disorders.

The role of autophagy in cardiovascular disease: Cross-interference of signaling pathways and underlying therapeutic targets

Autophagy is a conserved lysosomal pathway for the degradation of cytoplasmic proteins and organelles, which realizes the metabolic needs of cells and the renewal of organelles. Autophagy-related genes (ATGs) are the main molecular mechanisms controlling autophagy, and their functions can coordinate the whole autophagic process. Autophagy can also play a role in cardiovascular disease through several key signaling pathways, including PI3K/Akt/mTOR, IGF/EGF, AMPK/mTOR, MAPKs, p53, Nrf2/p62, Wnt/β-catenin and NF-κB pathways. In this paper, we reviewed the signaling pathway of cross-interference between autophagy and cardiovascular diseases, and analyzed the development status of novel cardiovascular disease treatment by targeting the core molecular mechanism of autophagy as well as the critical signaling pathway. Induction or inhibition of autophagy through molecular mechanisms and signaling pathways can provide therapeutic benefits for patients. Meanwhile, we hope to provide a unique insight into cardiovascular treatment strategies by understanding the molecular mechanism and signaling pathway of crosstalk between autophagy and cardiovascular diseases.

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

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

Glutathione system enhancement for cardiac protection: pharmacological options against oxidative stress and ferroptosis

The glutathione (GSH) system is considered to be one of the most powerful endogenous antioxidant systems in the cardiovascular system due to its key contribution to detoxifying xenobiotics and scavenging overreactive oxygen species (ROS). Numerous investigations have suggested that disruption of the GSH system is a critical element in the pathogenesis of myocardial injury. Meanwhile, a newly proposed type of cell death, ferroptosis, has been demonstrated to be closely related to the GSH system, which affects the process and outcome of myocardial injury. Moreover, in facing various pathological challenges, the mammalian heart, which possesses high levels of mitochondria and weak antioxidant capacity, is susceptible to oxidant production and oxidative damage. Therefore, targeted enhancement of the GSH system along with prevention of ferroptosis in the myocardium is a promising therapeutic strategy. In this review, we first systematically describe the physiological functions and anabolism of the GSH system, as well as its effects on cardiac injury. Then, we discuss the relationship between the GSH system and ferroptosis in myocardial injury. Moreover, a comprehensive summary of the activation strategies of the GSH system is presented, where we mainly identify several promising herbal monomers, which may provide valuable guidelines for the exploration of new therapeutic approaches.

Natural bioactive compounds-doxorubicin combinations targeting topoisomerase II-alpha: Anticancer efficacy and safety

Cancer is one of the leading causes of death worldwide, so pursuing effective and safe therapeutics for cancer is a key research objective nowadays. Doxorubicin (DOX) is one of the commonly prescribed chemotherapeutic agents that has been used to treat cancer with its antimitotic properties via inhibition of topoisomerase II (TOP2) activity. However, many problems hinder the broad use of DOX in clinical practice, including cardiotoxicity and drug resistance. Research in drug discovery has confirmed that natural bioactive compounds (NBACs) display a wide range of biological activities correlating to anticancer outcomes. The combination of NBACs has been seen to be an ideal candidate that might increase the effectiveness of DOX therapy and decreases its unfavorable adverse consequences. The current review discusses the chemo-modulatory mechanism and the protective effects of combined DOX with NBACs with a binding affinity (pKi) toward TOP2A more than pKi of DOX. This review will also discuss and emphasize the molecular mechanisms to provide a pathway for further studies to reveal other signaling pathways. Taken together, understanding the fundamental mechanisms and implications of combined therapy may provide a practical approach to battling cancer diseases.

Berberine Alleviates Doxorubicin-Induced Myocardial Injury and Fibrosis by Eliminating Oxidative Stress and Mitochondrial Damage via Promoting Nrf-2 Pathway Activation

Doxorubicin (DOX)-related cardiotoxicity has been recognized as a serious complication of cancer chemotherapy. Effective targeted strategies for myocardial protection in addition to DOX treatment are urgently needed. The purpose of this paper was to determine the therapeutic effect of berberine (Ber) on DOX-triggered cardiomyopathy and explore the underlying mechanism. Our data showed that Ber markedly prevented cardiac diastolic dysfunction and fibrosis, reduced cardiac malondialdehyde (MDA) level and increased antioxidant superoxide dismutase (SOD) activity in DOX-treated rats. Moreover, Ber effectively rescued the DOX-induced production of reactive oxygen species (ROS) and MDA, mitochondrial morphological damage and membrane potential loss in neonatal rat cardiac myocytes and fibroblasts. This effect was mediated by increases in the nuclear accumulation of nuclear erythroid factor 2-related factor 2 (Nrf2) and levels of heme oxygenase-1 (HO-1) and mitochondrial transcription factor A (TFAM). We also found that Ber suppressed the differentiation of cardiac fibroblasts (CFs) into myofibroblasts, as indicated by decreased expression of α-smooth muscle actin (α-SMA), collagen I and collagen III in DOX-treated CFs. Pretreatment with Ber inhibited ROS and MDA production and increased SOD activity and the mitochondrial membrane potential in DOX-challenged CFs. Further investigation indicated that the Nrf2 inhibitor trigonelline reversed the protective effect of Ber on both cardiomyocytes and CFs after DOX stimulation. Taken together, these findings demonstrated that Ber effectively alleviated DOX-induced oxidative stress and mitochondrial damage by activating the Nrf2-mediated pathway, thereby leading to the prevention of myocardial injury and fibrosis. The current study suggests that Ber is a potential therapeutic agent for DOX-induced cardiotoxicity that exerts its effects by activating Nrf2.

Protective role of cezanne in doxorubicin-induced cardiotoxicity by inhibiting autophagy, apoptosis and oxidative stress

Doxorubicin (DOX) is frequently used in clinical practice for its broad-spectrum effects. However, its benefit is limited by a series of complications, including excessive apoptosis and autophagy of cardiomyocytes, overproduction of reactive oxygen species (ROS) and high level of oxidative stress. As a new protein, OTU domain-containing 7B (OTUD7B), also called Cezanne, has been reported to regulate many pathological processes. However, whether it plays a role in DOX-induced cardiotoxicity is still unclear. We discovered that the Cezanne level was significantly increased in DOX-treated neonatal rat cardiomyocytes (NRCMs) and C57BL/6 J mice hearts. In vitro, the knockdown of Cezanne with adenovirus in NRCMs significantly worsened DOX-induced apoptosis, autophagy and oxidative stress, while Cezanne overexpression showed opposite results. In vivo, the overexpression of Cezanne using cardiomyocyte-targeted adeno-associated virus 9 (AAV9) significantly reduced cardiomyocyte apoptosis, autophagy and oxidative stress level when C57BL/6 J mice were subjected to DOX. Mechanistically, the overexpression of Cezanne significantly reversed the in-activation of the PI3K/AKT/mTOR pathway induced by DOX, while the inhibitors of this pathway abolished the effect of Cezanne, suggesting that the PI3K/AKT/mTOR pathway plays a role in the protective function of Cezanne. These findings indicate that Cezanne could ameliorate DOX-induced cardiotoxicity by attenuating the apoptosis and autophagy of cardiomyocytes and decreasing the level of oxidative stress.

Exploring the cardioprotective effects of canagliflozin against cisplatin-induced cardiotoxicity: Role of iNOS/NF-κB, Nrf2, and Bax/cytochrome C/Bcl-2 signals

Cardiotoxicity is a severe considerable side effect of cisplatin (CDDP) that requires much medical attention. The current study investigates the cardioprotective effects of canagliflozin (CA) against CDDP-induced heart toxicity. Rats were allocated to the control group; the CA group was administered CA 10 mg/kg/day orally for 10 days; the CDDP group was injected with 7 mg/kg, intraperitoneal as a single dose on the 5th day, and the CDDP + CA group. Compared to the CDDP-treated group, CA effectively attenuated CDDP-induced heart injury as evidenced by a decrease of serum aspartate aminotransferase, alkaline phosphatase, creatine kinase-MB, and lactate dehydrogenase enzymes and supported by the alleviation of histopathological changes in cardiac tissues. Biochemically, CA attenuated cardiac oxidative injury through upregulation of the nuclear factor-erythroid 2 related factor 2 (Nrf2) signal. CA suppressed inflammation by decreasing cardiac NO₂ ^- , MPO, iNOS, nuclear factor kappa B (NF-κB), tumor necrosis factor-alpha, and interleukin 1-beta levels. Besides, CA significantly upregulated cardiac levels of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and p-AKT proteins. Moreover, CA remarkably mitigated CDDP-induced apoptosis via modulation of Bax, cytochrome C, and Bcl-2 protein levels. Together, the present study revealed that CA could be a good candidate for preventing CDDP-induced cardiac injury by modulating iNOS/NF-κB, Nrf2, PI3K/AKT, and Bax/cytochrome C/Bcl-2 signals.

Heparin and Heparin-Based Drug Delivery Systems: Pleiotropic Molecular Effects at Multiple Drug Resistance of Osteosarcoma and Immune Cells

One of the main problems of modern health care is the growing number of oncological diseases both in the elderly and young population. Inadequately effective chemotherapy, which remains the main method of cancer control, is largely associated with the emergence of multidrug resistance in tumor cells. The search for new solutions to overcome the resistance of malignant cells to pharmacological agents is being actively pursued. Another serious problem is immunosuppression caused both by the tumor cells themselves and by antitumor drugs. Of great interest in this context is heparin, a biomolecule belonging to the class of glycosaminoglycans and possessing a broad spectrum of biological activity, including immunomodulatory and antitumor properties. In the context of the rapid development of the new field of “osteoimmunology,” which focuses on the collaboration of bone and immune cells, heparin and delivery systems based on it may be of intriguing importance for the oncotherapy of malignant bone tumors. Osteosarcoma is a rare but highly aggressive, chemoresistant malignant tumor that affects young adults and is characterized by constant recurrence and metastasis. This review describes the direct and immune-mediated regulatory effects of heparin and drug delivery systems based on it on the molecular mechanisms of (multiple) drug resistance in (onco) pathological conditions of bone tissue, especially osteosarcoma.

LKB1: An emerging therapeutic target for cardiovascular diseases

Cardiovascular diseases (CVDs) are currently the most common cause of morbidity and mortality worldwide. Experimental studies suggest that liver kinase B1 (LKB1) plays an important role in the heart. Several studies have shown that cardiomyocyte-specific LKB1 deletion leads to hypertrophic cardiomyopathy, left ventricular contractile dysfunction, and an increased risk of atrial fibrillation. In addition, the cardioprotective effects of several medicines and natural compounds, including metformin, empagliflozin, bexarotene, and resveratrol, have been reported to be associated with LKB1 activity. LKB1 limits the size of the damaged myocardial area by modifying cellular metabolism, enhancing the antioxidant system, suppressing hypertrophic signals, and inducing mild autophagy, which are all primarily mediated by the AMP-activated protein kinase (AMPK) energy sensor. LKB1 also improves myocardial efficiency by modulating the function of contractile proteins, regulating the expression of electrical channels, and increasing vascular dilatation. Considering these properties, stimulation of LKB1 signaling offers a promising approach in the prevention and treatment of heart diseases.

Mitochondrial activity is the key to the protective effect of β-Lapachone, a NAD+ booster, in healthy cells against cisplatin cytotoxicity

BACKGROUND

Cisplatin (CDDP) is a first-line chemotherapeutic drug for treating various cancers. However, CDDP also damages normal cells and causes many side effects. Recently, CDDP has been demonstrated to kill cancer cells by targeting mitochondria. Protecting mitochondria might be a potential therapeutic strategy for CDDP-induced side effects. β-Lapachone (β-lap), a recognized NAD⁺ booster, has been reported to regulate mitochondrial activity. However, it remains unclear whether maintaining mitochondrial activity is the key factor in the protective effects of β-lap in CDDP-treated normal cells.

PURPOSE

In this study, the protective effects of β-lap on mitochondria against CDDP cytotoxicity in normal cells were evaluated.

STUDY DESIGN

In vitro cell models were used in this study, including 3T3 fibroblasts, human dermal fibroblasts, MCF-7 breast cancer cells, and MDA-MB-231 breast cancer cells.

METHODS

Cells were treated with CDDP and β-lap, and cell survival, NAD⁺, mitochondrial activity, autophagy, and ATP production were measured. Various inhibitors and siRNAs were used to confirm the key signal underlying the protective effects of β-lap.

RESULTS

The results demonstrated that β-lap significantly decreased CDDP cytotoxicity in normal fibroblasts. With various inhibitors and siRNAs, β-lap reduced CDDP-induced damage to normal fibroblasts by maintaining mitochondrial activity and increasing autophagy through the NQO1/NAD⁺/SIRT1 axis. Most importantly, the protective effects of β-lap in fibroblasts did not affect the therapeutic effects of CDDP in cancer cells. This study indicated that mitochondrial activity, energy production, and NQO1 levels might be crucial responses separating normal cells from cancer cells under exposure to CDDP and β-lap.

CONCLUSION

β-lap could be a good synergistic drug for reducing the side effects of CDDP without affecting the anticancer drug effect.

The Interplay between Autophagy and Redox Signaling in Cardiovascular Diseases

Reactive oxygen and nitrogen species produced at low levels under normal cellular metabolism act as important signal molecules. However, at increased production, they cause damage associated with oxidative stress, which can lead to the development of many diseases, such as cardiovascular, metabolic, neurodegenerative, diabetes, and cancer. The defense systems used to maintain normal redox homeostasis plays an important role in cellular responses to oxidative stress. The key players here are Nrf2-regulated redox signaling and autophagy. A tight interface has been described between these two processes under stress conditions and their role in oxidative stress-induced diseases progression. In this review, we focus on the role of Nrf2 as a key player in redox regulation in cell response to oxidative stress. We also summarize the current knowledge about the autophagy regulation and the role of redox signaling in this process. In line with the focus of our review, we describe in more detail information about the interplay between Nrf2 and autophagy pathways in myocardium and the role of these processes in cardiovascular disease development.

The modulation of SIRT1 and SIRT3 by natural compounds as a therapeutic target in doxorubicin-induced cardiotoxicity: A review

Doxorubicin (DOX) is a potent antitumor agent with a broad spectrum of activity; however, irreversible cardiotoxicity resulting from DOX treatment is a major issue that limits its therapeutic use. Sirtuins (SIRTs) play an essential role in several physiological and pathological processes including oxidative stress, apoptosis, and inflammation. It has been reported that SIRT1 and SIRT3 can act as a protective molecular against DOX-induced myocardial injury through targeting numerous signaling pathways. Several natural compounds (NCs), such as resveratrol, sesamin, and berberine, with antioxidative, anti-inflammation, and antiapoptotic effects were evaluated for their potential to suppress the cardiotoxicity induced by DOX via targeting SIRT1 and SIRT3. Numerous NCs exerted their therapeutic effects on DOX-mediated cardiac damage via targeting different signaling pathways, including SIRT1/LKB1/AMPK, SIRT1/PGC-1α, SIRT1/NLRP3, and SIRT3/FoxO. SIRT3 also ameliorates cardiotoxicity by enhancing mitochondrial fusion.

Advances in understanding the role of P-gp in doxorubicin resistance: Molecular pathways, therapeutic strategies, and prospects

P-glycoprotein (P-gp) is a drug efflux transporter that triggers doxorubicin (DOX) resistance. In this review, we highlight the molecular avenues regulating P-gp, such as Nrf2, HIF-1α, miRNAs, and long noncoding (lnc)RNAs, to reveal their participation in DOX resistance. These antitumor compounds and genetic tools synergistically reduce P-gp expression. Furthermore, ATP depletion impairs P-gp activity to enhance the antitumor activity of DOX. Nanoarchitectures, including liposomes, micelles, polymeric nanoparticles (NPs), and solid lipid nanocarriers, have been developed for the co-delivery of DOX with anticancer compounds and genes enhancing DOX cytotoxicity. Surface modification of nanocarriers, for instance with hyaluronic acid (HA), can promote selectivity toward cancer cells. We discuss these aspects with a focus on P-gp expression and activity.

Role of acetylation in doxorubicin-induced cardiotoxicity

As a potent chemotherapeutic agent, doxorubicin (DOX) is widely used for the treatment of a variety of cancers However, its clinical utility is limited by dose-dependent cardiotoxicity, and pathogenesis has traditionally been attributed to the formation of reactive oxygen species (ROS). Accordingly, the prevention of DOX-induced cardiotoxicity is an indispensable goal to optimize therapeutic regimens and reduce morbidity. Acetylation is an emerging and important epigenetic modification regulated by histone deacetylases (HDACs) and histone acetyltransferases (HATs). Despite extensive studies of the molecular basis and biological functions of acetylation, the application of acetylation as a therapeutic target for cardiotoxicity is in the initial stage, and further studies are required to clarify the complex acetylation network and improve the clinical management of cardiotoxicity. In this review, we summarize the pivotal functions of HDACs and HATs in DOX-induced oxidative stress, the underlying mechanisms, the contributions of noncoding RNAs (ncRNAs) and exercise-mediated deacetylases to cardiotoxicity. Furthermore, we describe research progress related to several important SIRT activators and HDAC inhibitors with potential clinical value for chemotherapy and cardiotoxicity. Collectively, a comprehensive understanding of specific roles and recent developments of acetylation in doxorubicin-induced cardiotoxicity will provide a basis for improved treatment outcomes in cancer and cardiovascular diseases.

β-LAPachone is renoprotective in streptozotocin-induced diabetic mice via regulating the PI3K/Akt/mTOR signaling pathway

OBJECTIVES

β-LAPachone (B-LAP) is a natural product with established anti-inflammatory properties. In this study, we investigated the protective potential of B-LAP against diabetic nephropathy in streptozotocin (STZ) induced diabetic mice.

MATERIALS AND METHODS

Diabetes induction in mice was carried out by a single intraperitoneal injection of STZ. 2.5 mg/kg/day and 5 mg/kg/day doses of B-LAP were administered orally for twelve weeks and renal histoarchitecture, caspase-3, tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), glutathione peroxidase (GPX), as well as urinary nephrin and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated. Additionally, kidney levels of PI3K, phosphorylated (p)-Akt, p-mTOR, p-CREB, and SIRT1 were assessed in the present investigation.

RESULTS

5 mg/kg B-LAP significantly decreased urinary excretions of nephrin and NGAL. It also mitigated renal TNF-α and MDA levels and simultaneously improved GPX activities. 5 mg/kg B-LAP improved renal function in diabetic mice as indicated by elevated values of creatinine clearance. While B-LAP elevated renal levels of SIRT1, it alleviated PI3K, p-Akt, p-mTOR, and p-CREB levels in the kidneys of diabetic mice.

CONCLUSION

Collectively, these findings suggest B-LAP as a potential renoprotective agent in STZ-induced diabetic mice probably via modulating the PI3K/Akt/mTOR pathway.

A review on herbal Nrf2 activators with preclinical evidence in cardiovascular diseases

Cardiovascular diseases (CVDs) are an ever-growing problem and are the most common cause of death worldwide. The uncontrolled production of reactive oxygen species (ROS) and the activation of ROS associated with various cell signaling pathways with oxidative cellular damage are the most common pathological conditions connected with CVDs including endothelial dysfunction, hypercontractility of vascular smooth muscle, cardiac hypertrophy and heart failure. The nuclear factor E2-related factor 2 (Nrf2) is a basic leucine zipper redox transcription factor, together with its negative regulator, kelch-like ECH-associated protein 1 (Keap1), which serves as a key regulator of cellular defense mechanisms to combat oxidative stress and associated diseases. Multiple lines of evidence described here support the cardiac protective property of Nrf2 in various experimental models of cardiac related disease conditions. In this review, we emphasized the molecular mechanisms of Nrf2 and described the detailed outline of current findings on the therapeutic possibilities of the Nrf2 activators specifically from herbal origin in various CVDs. Based on evidence from various preclinical experimental models, we have highlighted the activation of Nrf2 pathway as a budding therapeutic option for the prevention and treatment of CVDs, which needs further investigation and validation in the clinical settings.

Molecular mechanisms of doxorubicin-induced cardiotoxicity: novel roles of sirtuin 1-mediated signaling pathways

Doxorubicin (DOX) is an anthracycline chemotherapy drug used in the treatment of various types of cancer. However, short-term and long-term cardiotoxicity limits the clinical application of DOX. Currently, dexrazoxane is the only approved treatment by the United States Food and Drug Administration to prevent DOX-induced cardiotoxicity. However, a recent study found that pre-treatment with dexrazoxane could not fully improve myocardial toxicity of DOX. Therefore, further targeted cardioprotective prophylaxis and treatment strategies are an urgent requirement for cancer patients receiving DOX treatment to reduce the occurrence of cardiotoxicity. Accumulating evidence manifested that Sirtuin 1 (SIRT1) could play a crucially protective role in heart diseases. Recently, numerous studies have concentrated on the role of SIRT1 in DOX-induced cardiotoxicity, which might be related to the activity and deacetylation of SIRT1 downstream targets. Therefore, the aim of this review was to summarize the recent advances related to the protective effects, mechanisms, and deficiencies in clinical application of SIRT1 in DOX-induced cardiotoxicity. Also, the pharmaceutical preparations that activate SIRT1 and affect DOX-induced cardiotoxicity have been listed in this review.

Long non-coding RNAs in the doxorubicin resistance of cancer cells

Chemotherapy is the main treatment used for cancer patients failing surgery. Doxorubicin (DOX) is a well-known chemotherapeutic agent capable of suppressing proliferation in cancer cells and triggering apoptosis via inhibiting topoisomerase II activity and producing DNA breaks. This activity of DOX restrains mitosis and cell cycle progression. However, frequent application of DOX results in the emergence of resistance in the cancer cells. It seems that genetic and epigenetic factors can provide DOX resistance of cancer cells. Long non-coding RNAs (lncRNAs) are a subcategory of non-coding RNAs with role in the regulation of several cellular processes such as proliferation, migration, differentiation and apoptosis. LncRNA dysregulation has been associated with chemoresistance, and this profile occurs upon DOX treatment of cancer. In the present review, we focus on the role of lncRNAs in mediating DOX resistance and discuss the molecular pathways and mechanisms. LncRNAs can drive DOX resistance via activating pathways such as NF-κB, PI3K/Akt, Wnt, and FOXC2. Some lncRNAs can activate protective autophagy in response to the stress caused by DOX, which mediates resistance. In contrast, there are other lncRNAs involved in the sensitivity of cancer cells to DOX, such as GAS5, PTCSC3 and FENDRR. Some anti-tumor agents such as polydatin can regulate the expression of lncRNAs, enhancing DOX sensitivity. Overall, lncRNAs are potential players in DOX resistance, and their identification and targeting are of importance in chemosensitivity. Furthermore, these findings can be translated into clinical for treatment of cancer patients.

Nrf2 Signaling Pathway in Chemoprotection and Doxorubicin Resistance: Potential Application in Drug Discovery

Doxorubicin (DOX) is extensively applied in cancer therapy due to its efficacy in suppressing cancer progression and inducing apoptosis. After its discovery, this chemotherapeutic agent has been frequently used for cancer therapy, leading to chemoresistance. Due to dose-dependent toxicity, high concentrations of DOX cannot be administered to cancer patients. Therefore, experiments have been directed towards revealing underlying mechanisms responsible for DOX resistance and ameliorating its adverse effects. Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is activated to increase levels of reactive oxygen species (ROS) in cells to protect them against oxidative stress. It has been reported that Nrf2 activation is associated with drug resistance. In cells exposed to DOX, stimulation of Nrf2 signaling protects cells against cell death. Various upstream mediators regulate Nrf2 in DOX resistance. Strategies, both pharmacological and genetic interventions, have been applied for reversing DOX resistance. However, Nrf2 induction is of importance for alleviating side effects of DOX. Pharmacological agents with naturally occurring compounds as the most common have been used for inducing Nrf2 signaling in DOX amelioration. Furthermore, signaling networks in which Nrf2 is a key player for protection against DOX adverse effects have been revealed and are discussed in the current review.

β-Lapachone Increases Survival of Septic Mice by Regulating Inflammatory and Oxidative Response

Sepsis is characterized by a dysregulated immune response to infection characterized by an early hyperinflammatory and oxidative response followed by a subsequent immunosuppression phase. Although there have been some advances in the treatment of sepsis, mortality rates remain high, urging for the search of new therapies. β-Lapachone (β-Lap) is a natural compound obtained from Tabebuia avellanedae Lorentz ex Griseb. with several pharmacological properties including bactericidal, anti-inflammatory, and antioxidant activity. Thus, the aim of this study was to evaluate the effects of β-Lap in a mouse sepsis model. To this, we tested two therapeutic protocols in mice submitted to cecal ligation and puncture- (CLP-) induced sepsis. First, we found that in pretreated animals, β-Lap reduced the systemic inflammatory response and improved bacterial clearance and mouse survival. Moreover, β-Lap also decreased lipid peroxidation and increased the total antioxidant capacity in the serum and peritoneal cavity of septic animals. In the model of severe sepsis, the posttreatment with β-Lap was able to increase the survival of animals and maintain the antioxidant defense function. In conclusion, the β-Lap was able to increase the survival of septic animals by a mechanism involving immunomodulatory and antioxidant protective effects.

Orosomucoid 1 Attenuates Doxorubicin-Induced Oxidative Stress and Apoptosis in Cardiomyocytes via Nrf2 Signaling

Doxorubicin (DOX) is an effective anticancer drug, but its therapeutic use is limited by its cardiotoxicity. The principal mechanisms of DOX-induced cardiotoxicity are oxidative stress and apoptosis in cardiomyocytes. Orosomucoid 1 (ORM1), an acute-phase protein, plays important roles in inflammation and ischemic stroke; however, the roles and mechanisms of ORM1 in DOX-induced cardiotoxicity remain unknown. Therefore, in the present study, we aimed to investigate the function of ORM1 in cardiomyocytes experiencing DOX-induced oxidative stress and apoptosis. A DOX-induced cardiotoxicity animal model was established in C57BL/6 mice by administering an intraperitoneal injection of DOX (20 mg/kg), and the control group was intraperitoneally injected with the same volume of sterilized saline. The effects were assessed after 7 d. Additionally, H9c2 cells were stimulated with DOX (10 μM) for 24 h. The results showed decreased ORM1 and increased oxidative stress and apoptosis after DOX stimulation in vivo and in vitro. ORM1 overexpression significantly reduced DOX-induced oxidative stress and apoptosis in H9c2 cells. ORM1 significantly increased the expression of nuclear factor-like 2 (Nrf2) and its downstream protein heme oxygenase 1 (HO-1) and reduced the expression of the lipid peroxidation end product 4-hydroxynonenal (4-HNE) and the level of cleaved caspase-3. In addition, Nrf2 silencing reversed the effects of ORM1 on DOX-induced oxidative stress and apoptosis in cardiomyocytes. In conclusion, ORM1 inhibited DOX-induced oxidative stress and apoptosis in cardiomyocytes by regulating the Nrf2/HO-1 pathway, which might provide a new treatment strategy for DOX-induced cardiotoxicity.

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.