Quercetin (QCT) is a natural polyphenolic compound enriched in human food, mainly in vegetables, fruits and berries. QCT and its main derivatives, such as rhamnetin, rutin, hyperoside, etc., have been documented to possess many beneficial effects in the human body including their positive effects in the cardiovascular system. However, clinical implications of QCT and its derivatives are still rare. In the current paper we provide a complex picture of the most recent knowledge on the effects of QCT and its derivatives in different types of cardiac injury, mainly in ischemia-reperfusion (I/R) injury of the heart, but also in other pathologies such as anthracycline-induced cardiotoxicity or oxidative stress-induced cardiac injury, documented in in vitro and ex vivo, as well as in in vivo experimental models of cardiac injury. Moreover, we focus on cardiac effects of QCT in presence of metabolic comorbidities in addition to cardiovascular disease (CVD). Finally, we provide a short summary of clinical studies focused on cardiac effects of QCT. In general, it seems that QCT and its metabolites exert strong cardioprotective effects in a wide range of experimental models of cardiac injury, likely via their antioxidant, anti-inflammatory and molecular pathways-modulating properties; however, ageing and presence of lifestyle-related comorbidities may confound their beneficial effects in heart disease. On the other hand, due to very limited number of clinical trials focused on cardiac effects of QCT and its derivatives, clinical data are inconclusive. Thus, additional well-designed human studies including a high enough number of patients testing different concentrations of QCT are needed to reveal real therapeutic potential of QCT in CVD. Finally, several negative or controversial effects of QCT in the heart have been reported, and this should be also taken into consideration in QCT-based approaches aimed to treat CVD in humans.

Iron is an essential mineral participating in different functions of the organism under physiological conditions. Numerous biological processes, such as oxygen and lipid metabolism, protein production, cellular respiration, and DNA synthesis, require the presence of iron, and mitochondria play an important role in the processes of iron metabolism. In addition to its physiological role, iron may be also involved in the adaptive processes of myocardial “conditioning”. On the other hand, disorders of iron metabolism are involved in the pathological mechanisms of the most common human diseases and include a wide range of them, such as type 2 diabetes, obesity, and non-alcoholic fatty liver disease, and accelerate the development of atherosclerosis. Furthermore, iron also exerts potentially deleterious effects that may be manifested under conditions of ischemia/reperfusion (I/R) injury, myocardial infarction, heart failure, coronary artery angioplasty, or heart transplantation, due to its involvement in reactive oxygen species (ROS) production. Moreover, iron has been recently described to participate in the mechanisms of iron-dependent cell death defined as “ferroptosis”. Ferroptosis is a form of regulated cell death that is distinct from apoptosis, necroptosis, and other types of cell death. Ferroptosis has been shown to be associated with I/R injury and several other cardiac diseases as a significant form of cell death in cardiomyocytes. In this review, we will discuss the role of iron in cardiovascular diseases, especially in myocardial I/R injury, and protective mechanisms stimulated by different forms of “conditioning” with a special emphasis on the novel targets for cardioprotection.

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells play essential roles in pathophysiological processes such as cardiac hypertrophy, cardiomyocyte survival and apoptosis, cardiac fibrosis, and angiogenesis in relation to CVDs. In this review, we will first outline the current knowledge about the physical characteristics, biological contents, and isolation methods of EVs. We will then focus on the functional roles of cardiovascular EVs and their pathophysiological effects in CVDs, as well as summarize the potential of EVs as therapeutic agents and biomarkers for CVDs. Finally, we will discuss the specific application of EVs as a novel drug delivery system and the utility of EVs in the field of regenerative medicine.

The oxidative stress plays an important role in the development of cardiovascular diseases (CVD). In CVD progression an aberrant redox regulation was observed. In this regulation levels of reactive oxygen species (ROS) play an important role in cellular signaling, where Nrf2 is the key regulator of redox homeostasis. Keap1-Nrf2-ARE system regulates a great set of detoxificant and antioxidant enzymes in cells after ROS and electrophiles exposure. In this review we focus on radical-generating systems in cardiovascular system as well as on Nrf2 as a target against oxidative stress and a key player of redox regulation in cardiovascular diseases. We also summarize the current knowledge about the role of Nrf2 in pathophysiology of several CVD (hypertension, cardiac hypertrophy, cardiomyopathies) as well as in cardioprotection against myocardial ischemia/ reperfusion injury.

The interest in non-coding RNAs, which started more than a decade ago, has still not weakened. A wealth of experimental and clinical studies has suggested the potential of non-coding RNAs, especially the short-sized microRNAs (miRs), to be used as the new generation of therapeutic targets and biomarkers of cardiovascular disease, an ever-growing public health issue in the modern world. Among the hundreds of miRs characterized so far, microRNA-1 (miR-1) and microRNA-21 (miR-21) have received some attention and have been associated with cardiac injury and cardioprotection. In this review article, we summarize the current knowledge of the function of these two miRs in the heart, their association with cardiac injury, and their potential cardioprotective roles and biomarker value. While this field has already been extensively studied, much remains to be done before research findings can be translated into clinical application for patient’s benefit.