ETHNOPHARMACOLOGICAL RELEVANCE:Radiation-induced heart disease (RIHD) is one of the most serious complications in patients receiving chest radiotherapy, partially offsetting its benefits. At present, there is a lack of effective treatments for RIHD. Ferroptosis is a newly discovered type of cell death that results from iron-dependent lipid peroxide accumulation. It was recently shown that irradiation generates severe ferroptosis, providing new insights for the treatment of RIHD. Abelmoschus manihot (L.) possesses excellent pharmacological properties and is widely used in treating various ischemic heart and brain diseases; however, its efficacy and mechanism in treating RIHD are unknown. AIM:This study aimed to investigate the efficacy and mechanism of total extracts from A. manihot (L.) (TEA) in treating RIHD. MATERIALS AND METHODS:C57BL/6 mice and H9C2 cells were exposed to irradiation to induce RIHD in vivo and in vitro, respectively. In vivo, we evaluated the protective effects of TEA (150 and 300 mg/kg) on RIHD. Body and heart weight changes of mice were calculated in each group, and malondialdehyde (MDA) level, glutathione/oxidized glutathione (GSH/GSSH) and nicotinamide adenine dinucleotide phosphate (NADPH/NADP) ratios, western blot, heart histology, and immunohistochemistry were used to evaluate TEA effectiveness. We identified the potential mechanism of radiation-induced cardiomyocyte injury in H9C2 cells treated with small interfering RNA. We determined the effective dose of TEA (0.6 mg/mL) using a Cell Counting Kit-8 assay. Intracellular Fe and lipid peroxidation levels were detected by Phen Green™ SK diacetate probe, BODIPY 581/591 C11 staining, and MDA, GSH, and NADPH kits, and the level of target protein was evaluated by immunofluorescence and western blot. RESULTS:Radiation inhibited system Xc-cystine (xCT)/glutathione peroxidase 4 (GPX4) expression and activity in cardiomyocytes in a time and dose-dependent manner. After silencing xCT/GPX4, MDA significantly increased and GSH/GSSH and NADPH/NADP ratios were reduced. xCT/GPX4 inhibition drove ferroptosis in radiation-induced H9C2 injury. Oxidative stress in H9C2 was significantly enhanced by irradiation, which also significantly increased NADPH oxidase 4 (NOX4) expression and inhibited nuclear factor E2-related factor 2 (Nrf2) expression in vivo and in vitro. Inhibition of xCT/GPX4 drove ferroptosis in radiation-induced H9C2 injury, which was aggravated by inactivation of Nrf2 and alleviated by inhibition of NOX4. Compared with the ionizing radiation-only group, TEA improved body weight loss, MDA levels, and histological changes induced by irradiation in mice hearts, and increased the ratio of GSH/GSSH and NADPH/NADPin vivo; it also reduced lipid peroxidation and intracellular Fe accumulation, restored MDA levels, and elevated the ratios of GSH/GSSH and NADPH/NADP in irradiation-injured H9C2 cells. TEA up-regulated Nrf2, xCT, and GPX4 expression and inhibited NOX4 expression in vivo and in vitro. CONCLUSIONS:Ferroptosis induced by redox imbalance mediated through the NOX4/xCT/GPX4 axis is a potential mechanism behind radiation-induced cardiomyocyte injury, and can be prevented by TEA.

PURPOSE OF REVIEW:Cardiomyopathy is a significant complication of various cancer treatments and has been best studied in patients receiving anthracyclines and trastuzumab. This paper evaluates strategies to prevent chemotherapy-induced cardiotoxicity. RECENT FINDINGS:Increasing cumulative anthracycline dose, use of ≥2 cardiotoxic therapies, extremes of age, and pre-existing cardiovascular risk factors, or established cardiovascular disease, heighten the risk of developing chemotherapy-induced cardiomyopathy. Continuous rather than bolus anthracycline infusions, liposomal doxorubicin, or concomitant dexrazoxane reduces chemotherapy-induced cardiotoxicity. Treatment with neurohormonal antagonists or statins and exercise training during chemotherapy are promising, but as yet unproven, cardioprotective strategies. Identification of high-risk patients and optimization of their underlying cardiovascular risk factors/disease are essential to prevent cardiotoxicity. In patients requiring high-dose anthracyclines, continuous infusions, liposomal doxorubicin, or dexrazoxane should be considered to mitigate cardiotoxicity. Current data do not support the routine use of neurohormonal antagonists or statins as cardioprotective agents in patients treated with cardiotoxic chemotherapies.

AIMS:Azithromycin is widely used broad spectrum antibiotic recently used in treatment protocol of COVID-19 for its antiviral and immunomodulatory effects combined with Hydroxychloroquine or alone. Rat models showed that Azithromycin produces oxidative stress, inflammation, and apoptosis of myocardial tissue. Rosuvastatin, a synthetic statin, can attenuate myocardial ischemia with antioxidant and antiapoptotic effects. This study aims to evaluate the probable protective effect of Rosuvastatin against Azithromycin induced cardiotoxicity. MAIN METHOD:Twenty adult male albino rats were divided randomly into four groups, five rats each control, Azithromycin, Rosuvastatin, and Azithromycin +Rosuvastatin groups. Azithromycin 30 mg/kg/day and Rosuvastatin 2 mg/kg/day were administrated for two weeks by an intragastric tube. Twenty-four hours after the last dose, rats were anesthetized and the following measures were carried out; Electrocardiogram, Blood samples for Biochemical analysis of lactate dehydrogenase (LDH), and creatine phosphokinase (CPK). The animals sacrificed, hearts excised, apical part processed for H&E, immunohistochemical staining, and examined by light microscope. The remaining parts of the heart were collected for assessment of Malondialdehyde (MDA) and Reduced Glutathione (GSH). KEY FINDINGS:The results revealed that Rosuvastatin significantly ameliorates ECG changes, biochemical, and Oxidative stress markers alterations of Azithromycin. Histological evaluation from Azithromycin group showed marked areas of degeneration, myofibers disorganization, inflammatory infiltrate, and hemorrhage. Immunohistochemical evaluation showed significant increase in both Caspase 3 and Tumor necrosis factor (TNF) immune stain. Rosuvastatin treated group showed restoration of the cardiac muscle fibers in H&E and Immunohistochemical results. SIGNIFICANCE:We concluded that Rosuvastatin significantly ameliorates the toxic changes of Azithromycin on the heart.

In addition to their lipid-lowering properties, statins improve endothelial function by increasing the activity of endothelial nitric oxide synthase (eNOS). It was hypothesized that, by this mechanism, statins protect the myocardium from ischemia/reperfusion injury in normocholesterolemic animals. Rats were pretreated for 1 week with either cerivastatin (0.3 mg/kg/d) or placebo. Anesthetized animals underwent 30 minutes of coronary artery occlusion (CAO) followed by 180 minutes of reperfusion. In a separate set of experiments, the NOS inhibitor l-NAME (15 mg/kg; N -nitro-l-arginine methyl ester) was administered 15 minutes before CAO. Cerivastatin decreased infarct size by 49% (P < 0.05) without reducing plasma cholesterol levels. Cerivastatin increased myocardial eNOS mRNA and NOS activity and by 52% and 58% (P < 0.05), respectively. Cardioprotection and upregulation of eNOS activity evoked by cerivastatin were not observed in rats cotreated with l-NAME. These results show that statins reduce the extent of myocardial necrosis in normocholesterolemic rats after acute ischemia/reperfusion injury by increasing myocardial eNOS activity. Therefore, statins may protect the heart not only by reducing the incidence of ischemic events, but also by limiting cell damage during acute myocardial infarction.

The present study was carried out to evaluate the protective effect of different statins on isoproterenol (ISO) induced myocardial necrosis. Atorvastatin, rosuvastatin, fluvastatin, simvastatin and pravastatin (10 mg/kg/day) were administered for 12 weeks. After pretreatment of 12 weeks myocardial necrosis was induced by subsequent injection of ISO (85 mg/kg/day, s.c.) to wistar rats. Serum biochemical parameters like glucose, lipid profile, cardiac markers and transaminases were evaluated. Animals were killed and heart was excised for histopathology and antioxidant study. Statins pretreated rats showed significant protection against ISO induced elevation in serum biochemical parameters and serum level of cardiac marker enzymes and transaminase level as compared to ISO control group. Mild to moderate protection was observed in different statins treated heart in histopathology and TTC stained sections. Result from our study also revealed that statins could efficiently protect against ISO intoxicated myocardial necrosis by impairing membrane bound enzyme integrity and endogenous antioxidant enzyme levels. Amongst all statins used, rosuvastatin and pravastatin were found to have maximum cardio-protective activity against ISO induced myocardial necrosis as compared to other statins.

Large-scale intervention trials demonstrate that treatment with statins, the most effective lipid lowering drug class, significantly reduces the risk of coronary heart disease events. Recent evidence suggests that more aggressive LDL cholesterol lowering with newly developed statins may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. There is increasing evidence that statins exert a myriad of other beneficial pleiotropic effects on the vascular wall, thus altering the course of atherosclerotic disease. In the long-term treatment, non-life-threatening side effects may occur in up to 15% of patients receiving one statin. Significant elevations in the activity of serum aminotransferase and creatine kinase alone or in combination with muscle pain in statin-treated patients should be taken seriously. The combination of the statins with gemfibrozil results in higher rates of drug toxicity. Reports show possible adverse effects of statins on nervous system function including mood alterations, however, statins have also been associated with improvement in central nervous system disorders. Special attention must be paid to the tolerability of the statins in children, elderly and transplant patients. Future clinical studies and surveillance information will warrant long term safety of each member of this class of lipid-lowering agents. New classes of patients with diabetes, metabolic syndrome and renal diseases may have clinical benefits from statins. New upcoming clinical trials will address the fundamental question of whether statin treatment can protect from the natural history of atherosclerotic-related diseases. This will require a more prolonged follow-up (i.e., 10 to 15 years). Finally, the basic understanding of newer pathogenic mechanisms involving the effects of statins on angiogenesis and the nitric oxide pathway should be explored in the clinical setting as well as the study of pathogenic mechanisms by which statins can affect plaque instability.

OBJECTIVE:To identify redundant clinical trials evaluating statin treatment in patients with coronary artery disease from mainland China, and to estimate the number of extra major adverse cardiac events (MACEs) experienced by participants not treated with statins in those trials. DESIGN:Cross sectional study. SETTING:2577 randomized clinical trials comparing statin treatment with placebo or no treatment in patients with coronary artery disease from mainland China, searched from bibliographic databases to December 2019. PARTICIPANTS:250 810 patients with any type of coronary artery disease who were enrolled in the 2577 randomized clinical trials. MAIN OUTCOME MEASURES:Redundant clinical trials were defined as randomized clinical trials that initiated or continued recruiting after 2008 (ie, one year after statin treatment was strongly recommended by clinical practice guidelines). The primary outcome is the number of extra MACEs that were attributable to the deprivation of statins among patients in the control groups of redundant clinical trials-that is, the number of extra MACEs that could have been prevented if patients were given statins. Cumulative meta-analyses were also conducted to establish the time points when statins were shown to have a statistically significant effect on coronary artery disease. RESULTS:2045 redundant clinical trials were identified published between 2008 and 2019, comprising 101 486 patients in the control groups not treated with statins for 24 638 person years. 3470 (95% confidence interval 3230 to 3619) extra MACEs were reported, including 559 (95% confidence interval 506 to 612) deaths, 973 (95% confidence interval 897 to 1052) patients with new or recurrent myocardial infarction, 161 (132 to 190) patients with stroke, 83 (58 to 105) patients requiring revascularization, 398 (352 to 448) patients with heart failure, 1197 (1110 to 1282) patients with recurrent or deteriorated angina pectoris, and 99 (95% confidence interval 69 to 129) unspecified MACEs. CONCLUSIONS:Of more than 2000 redundant clinical trials on statins in patients with coronary artery disease identified from mainland China, an extra 3000 MACEs, including nearly 600 deaths, were experienced by participants not treated with statins in these trials. The scale of redundancy necessitates urgent reform to protect patients.

Endothelial dysfunction is now recognised as an important process in the pathogenesis of atherosclerosis. Nitric oxide (NO) release by the endothelium regulates blood flow, inflammation and platelet aggregation, and consequently its disruption during endothelial dysfunction can decrease plaque stability and encourage the formation of atherosclerotic lesions and thrombi. Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) are often utilised in the prevention of coronary heart disease due to their efficacy at lowering lipid levels. However, statins may also prevent atherosclerotic disease by non-lipid or pleiotropic effects, for example, improving endothelial function by promoting the production of NO. There are various mechanisms whereby statins may alter NO release, such as inhibiting the production of mevalonate and important isoprenoid intermediates, thereby preventing the isoprenylation of the small GTPase Rho, which negatively regulates the expression of endothelial nitric oxide synthase (eNOS). Furthermore, statins may also increase eNOS activity via post-translational activation of the phosphatidylinositol 3-kinase/protein kinase Akt (PI3 K/Akt) pathway and/or through an interaction with the molecular chaperone heat-shock protein 90 (HSP90). Data suggest that statins may vary in their efficacy for enhancing the release of NO, and the mechanisms dictating these differences are not yet clear. By increasing NO production, statins may interfere with atherosclerotic lesion development, stabilise plaque, inhibit platelet aggregation, improve blood flow and protect against ischaemia. Therefore, the ability of statins to improve endothelial function through the release of NO may partially account for their beneficial effects at reducing the incidence of cardiovascular events.

Lipid-lowering using HMG-CoA reductase inhibitors or statin therapy forms the cornerstone of medical therapy in the primary and secondary prevention of cardiovascular disease. In addition, to the improvements in lipid profile, the beneficial effects elicited by this class of drugs may be attributed to their diverse variety of non-lipid lowering pleiotropic effects, including improved endothelial function, reduced oxidative stress, less platelet adhesion, and increased atherosclerotic plaque stability. A less appreciated effect of statin therapy that has been reported in experimental studies is its cardioprotective effect with respect to its ability to directly protect the myocardium from the detrimental effects of acute ischaemia-reperfusion injury. In the current article we review the cardioprotective effects of statin therapy beyond serum lipid lowering, the underlying mechanisms involved and the potential implications for patients with coronary heart disease.

In the recent years, some clinical and experimental studies have suggested that the use of statins may protect against atrial fibrillation (AF). A relation between inflammation and the development of AF has been described, and the potent anti-inflammatory and antioxidant properties of statins may make them effective in preventing the development of AF. A global analysis of the literature suggests that the use of statins is associated with a decreased risk of incidence or recurrence of AF in some cases. However, this beneficial effect is not seen for all types of AF in all the patients. The use of statins seems associated 1) with a lack of benefit in primary prevention of AF, 2) with a significant but heterogeneous decreased risk of recurrence of AF in secondary prevention, and 3) with a very significant and homogeneous reduction for the risk of post operative AF. An intensive lipid lowering statin regimen does not provide greater protection against AF. Patients with coronary heart disease are curr ently treated with statins in most cases, and this may not have an impact on their treatment. In contrast, it remains to determine more accurately if statins may bring a significant benefit for some AF patients without any type of established atherosclerotic disease or with a low risk of atherogenesis. Since it remains uncertain whether the suppression of AF in these patients is beyond doubt beneficial, prescribing statins for this purpose alone should not be recommended at the present time.

PURPOSE OF REVIEW:Clinical studies suggested that 3-hydroxyl-3-methylglutaryl coenzyme A reductase inhibitor (statin) therapy has an additional cardiovascular protective activity that may function independently of the ability of statins to lower serum cholesterol. This paper reviews the available data on these effects and discusses the potential intracellular mechanisms involved. RECENT FINDINGS:Experimental studies have clearly shown that statins protect against ischaemia-reperfusion injury of the heart, and exert pro-angiogenic effects by stimulating the growth of new blood vessels in ischaemic limbs of normocholesterolemic animals. The mechanisms underlying these serum lipid-independent statin effects are not completely understood, but there is increasing evidence that statins improve endothelial function through molecular mechanisms that mediate an increase in endothelium-derived nitric oxide. Recent research has revealed a link between statins and the serine/threonine protein kinase Akt that regulates multiple angiogenic processes in endothelial cells. In contrast to these data, it has also been reported that higher doses of statins can inhibit endothelial cell migration and angiogenesis. SUMMARY:Statins have biphasic potential either to promote or inhibit angiogenesis. Low statin doses induce a pro-angiogenic effect through Akt activation and increase nitric oxide production, whereas high statin doses may decrease protein prenylation and inhibit cell growth. Notwithstanding, the clinical relevance of these serum lipid-independent effects is not fully understood. Further studies on the actions of statins on endothelial cells may lead to the identification of new pharmacological targets for the control of angiogenesis.

Clinical studies indicate that 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) therapy has a cardiovascular protective activity that may result from an improvement in endothelial function. Experimental studies have shown that statins protect against ischaemia-reperfusion injury of the heart and stimulate the growth of new blood vessels in ischemic limbs of normocholesterolemic animals. The mechanisms underlying these serum lipid-independent effects of statins are not completely understood, but there is increasing evidence that they improve endothelial function through molecular mechanisms that mediate an increase in endothelium-derived nitric oxide. Recent research has revealed a link between statins and the serine/threonine protein kinase Akt that regulates multiple angiogenic processes in endothelial cells, including the generation of nitrous oxide. In contrast to these data, it has also been reported that higher doses of statins inhibit endothelial cell migration and angiogenesis. Thus, further studies on the actions of statins may lead to the identification of new pharmacological targets for the control of blood vessel growth.

In addition to their lipid-modulating properties, statins have a large number of beneficial cardiovascular effects that have emerged over time and that were not anticipated during drug development. The lipid and nonlipid effects act in a concerted way to reduce the ischemic burden of the myocardium and to protect it against injury. By acting on the vessel wall, statins may prevent lesion initiation and repair injuries, enhance myocardial perfusion, slow lesion progression, and prevent coronary occlusion. They may also directly reduce myocardial damage, favor myocardial repair, and protect against immune injury. This review focuses on properties of statins that contribute to their cardioprotective effect. The first section includes information on modulation of vascular tone, endothelial permeability and function, inhibition of complement injury, curbing of foam cell formation, antioxidant and anti-inflammatory properties, and profibrinolytic and anticoagulant activities. The second section relates to reduction of myocardial necrosis, myocardial hypertrophy, blood pressure, and heart failure, as well as mobilization of endothelial progenitor cells for repair, angiogenic effects, and immunomodulation. In many instances, results of in vitro and animal studies have raised expectations and prompted studies in humans. Several clinical trials have confirmed these expectations and have strengthened the value of statins as valuable antiatherosclerotic and cardioprotective agents.