Quercetin offers cardioprotection against progression of experimental autoimmune myocarditis by suppression of oxidative and endoplasmic reticulum stress via endothelin-1/MAPK signalling

Fischer's oligopeptide ratio in ischemic hypoxia: prophylactic amendment of sophoretin and melatonin supplementation

Aim: The fundamental pathophysiology of ischemic-hypoxia is oxygen depletion. Fischer's ratio is essential for monitoring hypoxia intensity. Methods: the current study highlighted the prophylactic role of sophoretin (QRC) and/or melatonin (MLN) versus sodium nitrite (SN) brain hypoxia. Results: Prophylactic treatment with sophoretin and MLN, was preceded with hypoxia-induction via sodium nitrite (60 mg/kg, S.C.). SN decreased hemoglobin (Hb), elevated HIF-α, HSP-70, IL-6 and TNF-α. Sophoretin and/or MLN restored the ameliorated inflammatory biomarkers, modulated norepinephrine, dopamine, serotonin and gamma-aminobutyric acid (GABA). Similarly, single-cell gel electrophoresis (SCGE or COMET) DNA damage assay confirmed this finding. Conclusion: Treatment via sophoretin and MLN was the most effective therapy for improving sodium nitrite-induced brain injury.

Cardioprotective Effects of Solidago microglossa DC. in Nicotine-Treated Hypertensive Rats

Solidago microglossa DC. (Asteraceae), "arnica brasileira," is a Brazilian species popularly used to treat hypertension or renal ailments. This study investigated the cardioprotective effects of standardized S. microglossa extract (EESM) in nicotine-treated spontaneously hypertensive rats (SHRs). Moreover, the molecular mechanisms involved in the cardiovascular effects were also investigated. The acute toxicity was evaluated in female Wistar rats. Afterwards, six-month-old male spontaneously hypertensive rats received the EESM (14, 28, and 56 mg/kg), hydrochlorothiazide (25 mg/kg), and vehicle (filtered water; 0.1 mL/100 g) once daily for 28 days. All treatments were associated with 1.8 mg/kg of nicotine. At the end of the experimental period, the renal function, electrocardiographic profile, blood pressure, ventricular function, biochemical parameter, and mesenteric vascular bed reactivity were evaluated. Relative organ weights and cardiac morphometry were also investigated. Nicotine treatment in 6-month-old SHRs induced a significant reduction in renal function, with reduced urinary volume and lower renal elimination of sodium and creatinine. In addition, serum markers of the redox state and blood pressure levels remained significantly elevated, contributing to changes in vascular reactivity and left ventricular hypertrophy associated with reduced ventricular function. After 28 days of treatment, we found that the highest dose of EESM could mitigate all renal and cardiovascular changes developed by the nicotine-treated hypertensive rats. This study presented EESM as a possible cardioprotective drug that prevents cardiovascular dysfunctions in nicotine-treated hypertensive rats. Our data suggest EESM as a potential adjuvant therapy when cardioprotective effects are required.

Cardioprotective effect of Sanguisorba minor against isoprenaline-induced myocardial infarction in rats

Introduction: Oxidative stress is a major instigator of various cardiovascular diseases, including myocardial infarction (MI). Despite available drugs, there is still an increased need to look for alternative therapies or identify new bioactive compounds. Sanguisorba minor (S. minor) is a native herb characterized by its potent antioxidant activity. This study was designed to evaluate the effect of S. minor against isoprenaline-induced MI. Methods: Rats were treated with the hydro-ethanolic extract of the aerial parts of S. minor at doses of 100 or 300 mg/kg orally for 9 days. Isoprenaline was injected subcutaneously at the dose of 85 mg/kg on days 8 and 9. Then, the activities of various cardiac injury markers including cardiac troponin (cTnT), lactate dehydrogenase (LDH), creatinine kinase muscle brain (CK-MB), creatinine phosphokinase (CPK), and antioxidant enzymes in serum were determined. Malondialdehyde (MDA) and thiol content were measured in cardiac tissue, and histopathological analysis was conducted. Results: Our results show that isoprenaline increased the serum levels of cTnT, LDH, CK-MB, and CPK (p < 0.001) and elevated MDA levels (p < 0.001) in cardiac tissue. Isoprenaline also reduced superoxide dismutase (SOD), catalase, and thiol content (p < 0.001). Importantly, the extract abolished isoprenaline-induced MI by elevating SOD and catalase (p < 0.001), reducing levels of MDA, and diminishing levels of cTnT, LDH, CK-MB, and CPK cardiac markers (p < 0.001). Histopathological studies of the cardiac tissue showed isoprenaline-induced injury that was significantly attenuated by the extract. Conclusion: Our results suggest that S. minor could abrogate isoprenaline-induced cardiac toxicity due to its ability to mitigate oxidative stress.

Resveratrol and beyond: The Effect of Natural Polyphenols on the Cardiovascular System: A Narrative Review

Cardiovascular diseases (CVDs) are among the leading causes of morbidity and mortality worldwide. Unhealthy dietary habits have clearly been shown to contribute to the development of CVDs. Beyond the primary nutrients, a healthy diet is also rich in plant-derived compounds. Natural polyphenols, found in fruits, vegetables, and red wine, have a clear role in improving cardiovascular health. In this review, we strive to summarize the results of the relevant pre-clinical and clinical trials that focused on some of the most important natural polyphenols, such as resveratrol and relevant flavonoids. In addition, we aim to identify their common sources, biosynthesis, and describe their mechanism of action including their regulatory effect on signal transduction pathways. Finally, we provide scientific evidence regarding the cardiovascular benefits of moderate, long-term red wine consumption.

Endoplasmic reticulum as a target in cardiovascular diseases: Is there a role for flavonoids?

Flavonoids are found in natural health products and plant-based foods. The flavonoid molecules contain a 15-carbon skeleton with the particular structural construction of subclasses. The most flavonoid's critical subclasses with improved health properties are the catechins or flavonols (e.g., epigallocatechin 3-gallate from green tea), the flavones (e.g., apigenin from celery), the flavanones (e.g., naringenin from citrus), the flavanols (e.g., quercetin glycosides from berries, onion, and apples), the isoflavones (e.g., genistein from soya beans) and the anthocyanins (e.g., cyanidin-3-O-glucoside from berries). Scientific data conclusively demonstrates that frequent intake of efficient amounts of dietary flavonoids decreases chronic inflammation and the chance of oxidative stress expressing the pathogenesis of human diseases like cardiovascular diseases (CVDs). The endoplasmic reticulum (ER) is a critical organelle that plays a role in protein folding, post-transcriptional conversion, and transportation, which plays a critical part in maintaining cell homeostasis. Various stimuli can lead to the creation of unfolded or misfolded proteins in the endoplasmic reticulum and then arise in endoplasmic reticulum stress. Constant endoplasmic reticulum stress triggers unfolded protein response (UPR), which ultimately causes apoptosis. Research has shown that endoplasmic reticulum stress plays a critical part in the pathogenesis of several cardiovascular diseases, including diabetic cardiomyopathy, ischemic heart disease, heart failure, aortic aneurysm, and hypertension. Endoplasmic reticulum stress could be one of the crucial points in treating multiple cardiovascular diseases. In this review, we summarized findings on flavonoids' effects on the endoplasmic reticulum and their role in the prevention and treatment of cardiovascular diseases.

Biochemical Investigation of Therapeutic Potentials of Plant-Based Bioactive Compounds as Stimulators of Glucagon like peptide-1 Secretion

This study was aimed to investigate the therapeutic potentials of plant-based bioactive compounds; lutein and resveratrol alone and/or in combination with DPP-4 enzyme inhibitor; sitagliptin on the secretion and bioavailability of Glucagon like peptide-1(GLP). For this, experimental rats were divided into seven groups. Group 1 was marked as control, while other six groups received streptozotocin (60 mg/kg I.P.). Later, group 2 was kept disease-control. While group 3 received 10 mg/kg/day sitagliptin (DDP-4i). Group 4 received 40 mg/kg/day lutein (LUT) and group 5 received 30 mg/kg/day resveratrol (RES). While group 6 and 7 were received combination of DPP-4i+LUT and DPP-4i+RES, respectively. Combined administration of DPP-4i+LUT or DPP-4i+RES showed expected therapeutic effects by lowering the fasting blood glucose and maintaining the serum insulin concentrations with improved glucose sensitivity and reduced insulin resistance. Further, co-administration of LUT and RES with DPP-4i revealed beneficial effects on measures of insulin resistance, circulating lipids, glycemic index, oxidative stress, and inflammatory status along with restoration of histological morphology of pancreatic cells and enterocytes that seemed to improve the level of GLP-1. Hence, substantial verdicts of this study showing therapeutic potentials of LUT and RES would surely help to recognize the potential effects in combination with DPP-4i as stimulators of GLP-1 secretion.

Hidden Agenda - The Involvement of Endoplasmic Reticulum Stress and Unfolded Protein Response in Inflammation-Induced Muscle Wasting

Critically ill patients at the intensive care unit (ICU) often develop a generalized weakness, called ICU-acquired weakness (ICUAW). A major contributor to ICUAW is muscle atrophy, a loss of skeletal muscle mass and function. Skeletal muscle assures almost all of the vital functions of our body. It adapts rapidly in response to physiological as well as pathological stress, such as inactivity, immobilization, and inflammation. In response to a reduced workload or inflammation muscle atrophy develops. Recent work suggests that adaptive or maladaptive processes in the endoplasmic reticulum (ER), also known as sarcoplasmic reticulum, contributes to this process. In muscle cells, the ER is a highly specialized cellular organelle that assures calcium homeostasis and therefore muscle contraction. The ER also assures correct folding of proteins that are secreted or localized to the cell membrane. Protein folding is a highly error prone process and accumulation of misfolded or unfolded proteins can cause ER stress, which is counteracted by the activation of a signaling network known as the unfolded protein response (UPR). Three ER membrane residing molecules, protein kinase R-like endoplasmic reticulum kinase (PERK), inositol requiring protein 1a (IRE1a), and activating transcription factor 6 (ATF6) initiate the UPR. The UPR aims to restore ER homeostasis by reducing overall protein synthesis and increasing gene expression of various ER chaperone proteins. If ER stress persists or cannot be resolved cell death pathways are activated. Although, ER stress-induced UPR pathways are known to be important for regulation of skeletal muscle mass and function as well as for inflammation and immune response its function in ICUAW is still elusive. Given recent advances in the development of ER stress modifying molecules for neurodegenerative diseases and cancer, it is important to know whether or not therapeutic interventions in ER stress pathways have favorable effects and these compounds can be used to prevent or treat ICUAW. In this review, we focus on the role of ER stress-induced UPR in skeletal muscle during critical illness and in response to predisposing risk factors such as immobilization, starvation and inflammation as well as ICUAW treatment to foster research for this devastating clinical problem.

Melissa officinalis L. Supplementation Provides Cardioprotection in a Rat Model of Experimental Autoimmune Myocarditis

Due to existing evidence regarding antioxidant and anti-inflammatory effects of Melissa officinalis extracts (MOEs), this study was aimed at investigating the potential of ethanolic MOE to prevent the development of myocarditis and its ability to ameliorate the severity of experimental autoimmune myocarditis (EAM) by investigating MOE effects on in vivo cardiac function, structure, morphology, and oxidative stress parameters. A total of 50 7-week-old male Dark Agouti rats were enrolled in the study and randomly allocated into the following groups: CTRL, nontreated healthy rats; EAM, nontreated rats with EAM; MOE50, MOE100, and MOE200, rats with EAM treated with either 50, 100, or 200 mg/kg of MOE for 3 weeks per os. Myocarditis was induced by immunization of the rats with porcine myocardial myosin (0.5 mg) emulsion on day 0. Cardiac function and dimensions of the left ventricle (LV) were assessed via echocardiography. Additionally, the blood pressure and heart rate were measured. On day 21, rats were sacrificed and the hearts were isolated for further histopathological analyses (H/E and Picrosirius red staining). The blood samples were collected to determine oxidative stress parameters. The EAM group characteristically showed greater LV wall thickness and lower ejection fraction (50.33 ± 7.94% vs. 84.81 ± 7.74%) and fractional shortening compared to CTRL (p < 0.05). MOE significantly improved echocardiographic parameters (EF in MOE200 81.44 ± 5.51%) and also reduced inflammatory infiltrate (by 88.46%; p < 0.001) and collagen content (by 76.39%; p < 0.001) in the heart tissues, especially in the MOE200 group compared to the EAM group. In addition, MOEs induced a significant decrease of prooxidants production (O₂⁻, H₂O₂, and TBARS) and improved antioxidant defense system via increase in GSH, SOD, and CAT compared to EAM, with medium and high dose being more effective than low dose (p < 0.05). The present study suggests that ethanolic MOEs, especially in a 200 mg/kg dose, improve cardiac function and myocardial architecture, possibly via oxidative stress mitigation, thus preventing heart remodeling, development of dilated cardiomyopathy, and subsequent heart failure connected with EAM. MOEs might be considered as a potentially helpful adjuvant therapy in patients with autoimmune myocarditis.

Protective role of nutraceuticals against myocarditis

Myocarditis is an inflammatory disease of the myocardium that mostly affects young adults. The disease is commonly caused by viral infection, medications, autoimmune disorders, and inflammatory conditions. Nearly 50% of the cases of myocarditis are due to post-viral immune response in a setting of an identifiable or non-identifiable infection. The clinical manifestation is nonspecific ranging from asymptomatic courses to sudden death in infants and young patients. This review describes the properties of phytochemicals as plant-derived active ingredients which can be used in the prevention and treatment of myocarditis and its associated risk factors. Meanwhile, it has illustrated epidemiological analyses, mechanism of action, and the metabolism of phytochemicals in animal and human clinical trials. We also mentioned the precise mechanism of action by which phytochemicals elicit their anti-viral, anti-inflammatory, antioxidant, and immunomodulatory effects and how they regulate signal transduction pathways. Nevertheless, comprehensive clinical trials are required to study the properties of phytochemicals in vivo, in vitro, and in silico for a proper management of myocarditis. Our findings indicate that phytochemicals function as potent adjunctive therapeutic drugs in myocarditis and its related complications.

Immune Mechanism, Gene Module, and Molecular Subtype Identification of Astragalus Membranaceus in the Treatment of Dilated Cardiomyopathy: An Integrated Bioinformatics Study

Astragalus membranaceus has complex components as a natural drug and has multilevel, multitarget, and multichannel effects on dilated cardiomyopathy (DCM). However, the immune mechanism, gene module, and molecular subtype of astragalus membranaceus in the treatment of DCM are still not revealed. Microarray information of GSE84796 was downloaded from the GEO database, including RNA sequencing data of seven normal cardiac tissues and ten DCM cardiac tissues. A total of 4029 DCM differentially expressed genes were obtained, including 1855 upregulated genes and 2174 downregulated genes. GO/KEGG/GSEA analysis suggested that the activation of T cells and B cells was the primary cause of DCM. WGCNA was used to obtain blue module genes. The blue module genes are primarily ADCY7, BANK1, CD1E, CD19, CD38, CD300LF, CLEC4E, FLT3, GPR18, HCAR3, IRF4, LAMP3, MRC1, SYK, and TLR8, which successfully divided DCM into three molecular subtypes. Based on the CIBERSORT algorithm, the immune infiltration profile of DCM was analyzed. Many immune cell subtypes, including the abovementioned immune cells, showed different levels of increased infiltration in the myocardial tissue of DCM. However, this infiltration pattern was not obviously correlated with clinical characteristics, such as age, EF, and sex. Based on network pharmacology and ClueGO, 20 active components of Astragalus membranaceus and 40 components of DMCTGS were obtained from TCMSP. Through analysis of the immune regulatory network, we found that Astragalus membranaceus effectively regulates the activation of immune cells, such as B cells and T cells, cytokine secretion, and other processes and can intervene in DCM at multiple components, targets, and levels. The above mechanisms were verified by molecular docking results, which confirmed that AKT1, VEGFA, MMP9, and RELA are promising potential targets of DCM.

Quercetin and its role in modulating endoplasmic reticulum stress: A review

The endoplasmic reticulum (ER) is the place where proteins and lipids are biosynthesized and where transmembrane proteins are folded. Both pathological and physiological situations may disturb the function of the ER, resulting in ER stress. Under stress conditions, the cells initiate a defensive procedure known as the unfolded protein response (UPR). Cases of severe stress lead to autophagy and/or the induction of cell apoptosis. Many studies implicate ER stress as a major factor contributing to many diseases. Therefore, the modulation of ER stress pathways has become an attractive therapeutic target. Quercetin is a plant-derived metabolite belonging to the flavonoids class which presents a range of beneficial effects including anti-inflammatory, cardioprotective, anti-oxidant, anti-obesity, anti-carcinogenic, anti-atherosclerotic, anti-diabetic, anti-hypercholesterolemic, and anti-apoptotic activities. Quercetin also has anti-cancer activity, and can be used as an adjuvant to decrease resistance to cancer chemotherapy. Furthermore, the effect of quercetin can be increased with the help of nanotechnology. This review discusses the role of quercetin in the modulation of ER stress (and related diseases) and provides novel evidence for the beneficial use of quercetin in therapy.

Quercetin Efficiently Alleviates TNF-α-Stimulated Injury by Signal Transducer and Activator of Transcription 1 and Mitogen-Activated Protein Kinase Pathway in H9c2 Cells: A Protective Role of Quercetin in Myocarditis

ABSTRACT

This study aimed to evaluate the protective effect of quercetin and its in-depth mechanism in TNF-α-stimulated cardiomyocytes. The differential expression of TNF-alpha (TNF-α) and signal transducer and activator of transcription 1 (STAT1) was analyzed based on the GEO database. H9c2 cells were stimulated with TNF-α to simulate myocarditis. Cell counting kit-8 assay and flow cytometry assay were performed to detect the cell viability and apoptosis. ELISA was used to measure the levels of proinflammatory cytokines (IL-6 and IL-17A) and anti-inflammatory cytokine (IL-10). STAT1 expression was downregulated by transfection with si-STAT1, and its expression was detected using quantitative real-time polymerase chain reaction and Western blot. Western blot was also performed to assess the expression of the mitogen-activated protein kinase (MAPK) pathway-related factors. In this article, TNF-α was highly expressed in patients with myocarditis, and TNF-α (20 μg/mL) declined the viability of H9c2 cells. Quercetin pretreatment partially alleviated the decrease of cell viability, the increase of apoptosis, and the release of inflammatory cytokines (IL-10, IL-6, and IL-17A) induced by TNF-α. In addition, TNF-α increased STAT1 expression, but quercetin prevented the TNF-α-increased STAT1 level. Remarkably, knockdown of STAT1 enhanced the protective effect of quercetin on TNF-α-injured H9c2 cells. Moreover, quercetin restrained the TNF-α-induced activation of the MAPK pathway. Also, the inhibitory effect of quercetin on the pathway was aggravated by STAT1 lacking. In summing, quercetin plays a protective role in TNF-α-stimulated H9c2 cell injury, which may be related to the regulation of STAT1 and MAPK pathway.

Study on Network Pharmacological Analysis and Preliminary Validation to Understand the Mechanisms of Plantaginis Semen in Treatment of Gouty Nephropathy

Plantaginis Semen (PS) has been used to promote diuresis and clear away dampness. Recent reports have shown that PS can be used to treat gouty nephropathy (GN). However, the action and mechanism of PS have not been well defined in treating GN. The present study aimed to define the molecular mechanisms of PS as a potential therapeutic approach to treat GN. A combination of network pharmacology and validation experiments in GN is used to understand the potential mechanism. Information on pharmaceutically active compounds in PS and gene information related to GN was obtained from public databases. The compound target network and protein-protein interaction network were constructed to study the mechanism of action of PS in the treatment of GN. The mechanism of action of PS in the treatment of GN was analyzed via Gene Ontology (GO) biological process annotation and Kyoto Gene and Genomics Encyclopedia (KEGG) pathway enrichment. Validation experiments were performed to verify the core targets. The GN rat model was prepared by the method of combining yeast and adenine. Hematoxylin-eosin (HE) staining was used to observe the morphology of renal tissue in rats. ELISA was applied to detect TGF-β1, TNF-α, and IL-1β levels in renal tissue. The expressions of TGF-β1, TNF-α, and IL-1β were determined using immunohistochemistry. Through the results of network pharmacology, we obtained 9 active components, 118 predicted targets, and 149 GN targets from the public database. Based on the protein-protein interaction (PPI), 26 hub genes for interaction with PS treating for GN were screened, including MMP9, TNF, IL1β, and IL6. The enrichment analysis results showed that the treatment of GN with PS was mainly involved in the TGF-β1 signaling pathway, MAPK signaling pathway, TNF signaling pathway, NF-κB signaling pathway, and PI3K Akt signaling pathway. Validation experiment results showed that PS could reduce the content of urinary protein and UA and deregulate the expression of TGF-β1, TNF-α, and IL-1β in the treatment of GN. The molecular mechanism of PS in the treatment of GN indicated the synergistic features of multicomponent, multitarget, and multipathway of traditional Chinese medicine, which provided an essential scientific basis for further elucidating the mechanism of PS in the treatment of GN.

Design, synthesis and pharmacological evaluation of ester-based quercetin derivatives as selective vascular KCa1.1 channel stimulators

Quercetin represents one of the most studied dietary flavonoids; it exerts a panel of pharmacological activities particularly on the cardiovascular system. Stimulation of vascular K_Ca1.1 channels contributes to its vasorelaxant activity, which is, however, counteracted in part by its concomitant stimulation of Ca_V1.2 channels. Therefore, several quercetin hybrid derivatives were designed and synthesized to produce a more selective K_Ca1.1 channel stimulator, then assessed both in silico and in vitro. All the derivatives interacted with the K_Ca1.1 channel with similar binding energy values. Among the selected derivatives, 1E was a weak vasodilator, though displaying an interesting Ca_V1.2 channel blocking activity. The lipoyl derivatives 1F and 3F, though showing pharmacological and electrophysiological features similar to those of quercetin, seemed to be more effective as K_Ca1.1 channel stimulators as compared to the parent compound. The strategy pursued demonstrated how different chemical substituents on the quercetin core can change/invert its effect on Ca_V1.2 channels or enhance its K_Ca1.1 channel stimulatory activity, thus opening new avenues for the synthesis of efficacious vasorelaxant quercetin hybrids.

Manipulation of Quercetin and Melatonin in the Down-Regulation of HIF-1α, HSP-70 and VEGF Pathways in Rat's Kidneys Induced by Hypoxic Stress

Hypoxia may lead to inflammatory responses by numerous signaling pathways. This investigation intended to inspect the defensive role of Quercetin (Quer) and/ or Melatonin (Mel) against reno toxicity induced by Sodium nitrite (Sod ntr). Sod ntr injection significantly decreased blood hemoglobin concentration (Hb) with a concurrent increase in serum tumor necrosis factor- α, interleukin-6, C-reactive protein, creatinine, and urea levels. Over protein-expression of vascular endothelial growth factor and heat shock, protein-70 and mRNA of HIF-1α were also observed. Pretreatment of the Sod ntr- injected rats with the aforementioned antioxidants; either alone or together significantly improved such parameters. Histopathological examination reinforced the previous results. It was concluded that the combined administration of Quer and Mel may be useful as a potential therapy against renal injury induced by Sod ntr. HIF-1α and HSP-70 are implicated in the induction of hypoxia and its treatment.

Genetic aspects of the oxidative phosphorylation dysfunction in dilated cardiomyopathy

Dilated cardiomyopathy is a frequent and extremely heterogeneous medical condition. Deficits in the oxidative phosphorylation system have been described in patients suffering from dilated cardiomyopathy. Hence, mutations in proteins related to this biochemical pathway could be etiological factors for some of these patients. Here, we review the clinical phenotypes of patients harboring pathological mutations in genes related to the oxidative phosphorylation system, either encoded in the mitochondrial or in the nuclear genome, presenting with dilated cardiomyopathy. In addition to the clinical heterogeneity of these patients, the large genetic heterogeneity has contributed to an improper allocation of pathogenicity for many candidate mutations. We suggest criteria to avoid incorrect assignment of pathogenicity to newly found mutations and discuss possible therapies targeting the oxidative phosphorylation function.

Potential Implications of Quercetin and its Derivatives in Cardioprotection

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.

Recent Advances on the Anti-Inflammatory and Antioxidant Properties of Red Grape Polyphenols: In Vitro and In Vivo Studies

In this review, special emphasis will be placed on red grape polyphenols for their antioxidant and anti-inflammatory activities. Therefore, their capacity to inhibit major pathways responsible for activation of oxidative systems and expression and release of proinflammatory cytokines and chemokines will be discussed. Furthermore, regulation of immune cells by polyphenols will be illustrated with special reference to the activation of T regulatory cells which support a tolerogenic pathway at intestinal level. Additionally, the effects of red grape polyphenols will be analyzed in obesity, as a low-grade systemic inflammation. Also, possible modifications of inflammatory bowel disease biomarkers and clinical course have been studied upon polyphenol administration, either in animal models or in clinical trials. Moreover, the ability of polyphenols to cross the blood-brain barrier has been exploited to investigate their neuroprotective properties. In cancer, polyphenols seem to exert several beneficial effects, even if conflicting data are reported about their influence on T regulatory cells. Finally, the effects of polyphenols have been evaluated in experimental models of allergy and autoimmune diseases. Conclusively, red grape polyphenols are endowed with a great antioxidant and anti-inflammatory potential but some issues, such as polyphenol bioavailability, activity of metabolites, and interaction with microbiota, deserve deeper studies.

Curcumin attenuates hypoxia/reoxygenation‑induced myocardial injury

Curcumin (Cur) has been reported to function as an antioxidant and anti-inflammatory agent and to play a role in anti-atherosclerosis. The present study aimed to explore the protective effect of Cur on hypoxia/reoxygenation (H/R) injury. The morphological changes in H9c2 cardiomyocytes were observed under an inverted microscope. Cell viability was determined by Cell Counting Kit-8 (CCK-8). Lactate dehydrogenase (LDH) level, malondialdehyde (MDA) level and the antioxidant superoxide dismutase (SOD) activity were determined by corresponding kits. Apoptosis and reactive oxygen species (ROS) levels were determined by flow cytometry. Endoplasmic reticulum (ER) stress-related factors, which were examined by quantitative real-time polymerase chain reaction (qPCR) and western blot analysis, included 78-kDa glucose-regulated protein (GRP78) and C/EBP homologous protein (CHOP). Extracellular signal regulating kinase 1/2 (ERK1/2), p38, c-Jun NH2-terminal kinase (JNK) and the phosphorylation levels of key proteins in the mitogen-activated protein kinase (MAPK) signaling pathway were all determined by western blot analysis. Compared to the control group, the cell morphology of the H9c2 cells was obviously altered upon H/R. Cell viability was significantly decreased, while apoptosis was significantly increased by H/R. We also observed that the levels of LDH and MDA were elevated and the activity of SOD was decreased in the H/R group. Notably, LDH, MDA and SOD levels were reversed following treatment with Cur; while apoptosis and ROS levels in the H/R injury group were decreased by Cur. H/R injury-triggered ER stress and the MAPK signaling pathway were suppressed by Cur. These results demonstrated that Cur has a protective effect on cardiomyocytes via suppression of ER stress and the MAPK pathway.

Polyphenols in the treatment of autoimmune diseases

In addition to protecting body from infections and diseases, the immune system produces auto-antibodies that can cause complex autoimmune disorders, such as Type I diabetes, primary biliary cirrhosis, rheumatoid arthritis, and multiple sclerosis, to name a few. In such cases, the immune system fails to recognize between foreign agents and its own body cells. Different factors, such as genetic factors (CD25, STAT4), epigenetic factors (DNA methylation, histone modifications) and environmental factors (xenobiotics, drugs, hormones) trigger autoimmunity. Glucocorticoids, non-steroidal anti-inflammatory drugs (NSAIDs), immunosuppressive and biological agents are currently used to manage autoimmune diseases of different origins. However, complete cure remains elusive. Many dietary and natural products including polyphenols have been widely studied as possible alternative treatment strategies for the management of autoimmune disorders. Polyphenols possess a wide-range of pharmacological and therapeutic properties, including antioxidant and anti-inflammatory activities. As immunomodulatory agents, polyphenols are emerging pharmaceutical tools for management of various autoimmune disorders including vitiligo, ulcerative colitis and multiple sclerosis (MS). Polyphenols activate intracellular pathways such as arachidonic acid dependent pathway, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, mitogen-activated protein kinases (MAPKs) pathway, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway and epigenetic modulation, which regulate the host's immune response. This timely review discusses putative points of action of polyphenols in autoimmune diseases, characterizing their efficacy and safety as therapeutic agents in managing autoimmune disorders.

The Effects of Periostin in a Rat Model of Isoproterenol: Mediated Cardiotoxicity

Periostin is an extracellular matrix protein from fasciclin family, and it plays an important role in the cell adhesion, migration, and growth of the organism. Periostin prevents apoptosis while stimulating cardiomyocytes. The present study was designed to investigate cardioprotective effects of the recombinant murine periostin peptide administration in a rat model of isoproterenol (ISO)-induced myocardial injury. The experiment was performed on 84 adult male Sprague Dawley rats in 4 groups (n = 21): control group (1), periostin-treated group (2), ISO-treated group (3), and ISO + periostin-treated group (4). The groups were further divided into three subgroups based on the duration of the experiment in which rats were killed on days 1, 7, and 28 (n = 7). Growth factors (VEGF, ANGPT, FGF-2, TGFβ), mitosis and apoptosis (Bcl-2, Bax, PCNA, Ki-67, phospho-histone H3), cell cycle activators and inhibitors (cyclin D1, D2, A2, Cdc2), the origin of regenerating cells (cKit and CD45) mRNA were detected using quantitative real-time polymerase chain reaction (PCR) and PCR array. Immunohistochemistry staining was used to directly detect protein level and distribution in the heart tissues. Administration of periostin following ISO-induced cardiotoxicity revealed that periostin alleviated deleterious effects of ISO through several pathways: (1) periostin induced mitotic activity of endothelial/fibroblastic cells, (2) periostin drives cardiomyocytes into S and M phases, thus promoting proliferation of cardiomyocytes, (3) periostin contributed to collagen degradation, tissue remodeling, and reduced cardiac fibrosis during the healing process following myocardial damage while preserving tissue matrix, (4) periostin stimulated angiogenesis by upregulating THBS1, TGFB2, and HGF genes, (5) periostin regulated cell growth and proliferation while maintaining cell shape and cellular muscle contractions (ACTB) and functioned as chemoattractant factor (CCL2) at the beginning of myocardial damage.

Basidiomycetes-X, an edible mushroom, alleviates the development of atopic dermatitis in NC/Nga mouse model

Basidiomycetes-X (BDM-X) is a novel edible mushroom recently identified as a new fungi species and is effective against oxidative stress and anti-inflammation associated with immune response. However the effect of BDM-X on atopic dermatitis (AD) has not been elucidated. In this study, we have investigated the effect of BDM-X on AD skin lesions in NC/Nga mouse model. AD-like lesion was induced by the application of house dust mite extract (DfE) to the dorsal skin of NC/Nga mouse. After AD induction, BDM-X was administered once daily for 2 weeks. We have analyzed the effects of BDM-X on dermatitis severity, histopathological changes and changes in inflammatory and proinflammatory proteins expressions in DfE induced AD mice skin. Treatment with BDM-X attenuated the development of AD-like clinical symptoms and effectively inhibited hyperkeratosis, parakeratosis, acanthosis and mast cells in AD mice skin. Furthermore, BDM-X treatment inhibited DfE induced tumor necrosis factor (TNF)α, high mobility group protein (HMG)B1, nuclear factor kappa (NFκ)B and inflammatory cytokines. These results indicate that BDM-X inhibits AD through modulating Th1 and Th2 responses and diminishing the mast cells infiltration in the skin lesions in NC/Nga mice.

Quercetin attenuates hypertension induced by sodium fluoride via reduction in oxidative stress and modulation of HSP 70/ERK/PPARγ signaling pathways

Hypertension is one of the silent killers in the world with high mortality and morbidity. The exposure of humans and animals to fluoride and/or fluoride containing compounds is almost inevitable. This study investigated the modulatory effects of quercetin on sodium fluoride (NaF)-induced hypertension and cardiovascular complications. Forty male rats were randomly separated into four groups (n =10). Group A animals served as the control, rats in Group B were exposed to 300 ppm of NaF, Groups C and D animals were exposed to 300 ppm of NaF along with quercetin orally at 50 mg/kg and 100 mg/kg orally by gavage, while NaF was administered in drinking water, respectively, for a week. Administration of NaF caused severe hypertension as indicated with significant increases in the systolic, diastolic, and mean arterial blood pressure, together with prolonged ventricular depolarization (QRS) and the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle (QT) intervals when compared with controls. NaF significantly decreased the activities of antioxidant enzymes, caused increase in markers of oxidative stress and renal damage when compared with controls. Immunohistochemical staining revealed lower expressions of Hsp70, ERK, and PPARγ in the heart, kidney, and aorta of rats-administered NaF relative to the controls. Together, quercetin co-treatment with NaF restored blood pressure, normalized QRS interval, and improved antioxidant defense system. © 2018 BioFactors, 44(5):465-479, 2018.

Therapeutic potential of quercetin as a cardiovascular agent

Flavonoids are integral components of various vegetation and in foods; consequently, they represent an inevitable part of the diet. Historical and epidemiological proof recommend that diet plans consisting of flavonoids such as quercetin have positive health benefits, especially on the heart. Flavonoids have been proven to be active against hypertension, inflammation, diabetes and vascular diseases. Quercetin exhibits significant heart related benefits as inhibition of LDL oxidation, endothelium-independent vasodilator effects, reduction of adhesion molecules and other inflammatory markers, the protective effect on nitric oxide and endothelial function under conditions of oxidative stress, prevention of neuronal oxidative and inflammatory damage and platelet antiaggregant effects. Searching for experimental evidence to validate the cardioprotective effects of quercetin, we review here the recent detailed in vivo studies. Quercetin and its derivatives lead to an enhancement in heart features, indicating the prospective for quercetin to be used therapeutically in the treatment of cardiac diseases. Several evidence-based studies suggest mechanisms to observe cardiovascular diseases such as aging effects, hypertension, angiotensin-converting enzyme activity and endothelial-dependent and independent functions. Different animal models including human are also used to elucidate the in vivo role of quercetin in cardiovascular diseases. The role of quercetin and its derivatives may go beyond their existence in food and has potential as a lead molecule in drug development programs.

The value of the Brazilian açai fruit as a therapeutic nutritional strategy for chronic kidney disease patients

Açai (Euterpe oleracea Mart.) fruit from the Amazon region in Brazil contains bioactive compounds such as α-tocopherol, anthocyanins (cyanidin 3-glycoside and cyanidin 3-rutinoside), and other flavonoids with antioxidant and anti-inflammatory properties. Moreover, the prebiotic activity of anthocyanins in modulating the composition of gut microbiota has emerged as an additional mechanism by which anthocyanins exert health-promoting effects. Açai consumption may be a nutritional therapeutic strategy for chronic kidney disease (CKD) patients since these patients present with oxidative stress, inflammation, and dysbiosis. However, the ability of açai to modulate these conditions has not been studied in CKD, and this review presents recent information about açai and its possible therapeutic effects in CKD.

Quercetin Prevents Diastolic Dysfunction Induced by a High-Cholesterol Diet: Role of Oxidative Stress and Bioenergetics in Hyperglycemic Rats

Alterations in cardiac energy metabolism play a key role in the pathogenesis of diabetic cardiomyopathy. Hypercholesterolemia associated with bioenergetic impairment and oxidative stress has not been well characterized in the cardiac function under glycemic control deficiency conditions. This work aimed to determine the cardioprotective effects of quercetin (QUE) against the damage induced by a high-cholesterol (HC) diet in hyperglycemic rats, addressing intracellular antioxidant mechanisms and bioenergetics. Quercetin reduced HC-induced alterations in the lipid profile and glycemia in rats. In addition, QUE attenuated cardiac diastolic dysfunction (increased E:A ratio), prevented cardiac cholesterol accumulation, and reduced the increase in HC-induced myocyte density. Moreover, QUE reduced HC-induced oxidative stress by preventing the decrease in GSH/GSSG ratio, Nrf2 nuclear translocation, HO-1 expression, and antioxidant enzymatic activity. Quercetin also counteracted HC-induced bioenergetic impairment, preventing a reduction in ATP levels and alterations in PGC-1α, UCP2, and PPARγ expression. In conclusion, the mechanisms that support the cardioprotective effect of QUE in rats with HC might be mediated by the upregulation of antioxidant mechanisms and improved bioenergetics on the heart. Targeting bioenergetics with QUE can be used as a pharmacological approach to modulate structural and functional changes of the heart under hypercholesterolemic and hyperglycemic conditions.

Natural products with anti-inflammatory and immunomodulatory activities against autoimmune myocarditis

Myocarditis is an inflammatory disease of the myocardium associated with immune dysfunction which may frequently lead to the development of dilated cardiomyopathy. Experimental autoimmune myocarditis is an animal model which mimics myocarditis in order to allow assessment of the therapeutic effects of different molecules on this disease. We aimed to review the inflammatory and immunological mechanisms involved in the pathogenesis of the myocarditis and finding natural products and phytochemicals with anti-myocarditis activities based on studies of cardiac myosin-induced experimental autoimmune myocarditis in rodents. A number of natural molecules (e.g. apigenin, berberine and quercetin) along with some plant extracts were found to be effective in alleviating experimental autoimmune myocarditis. Upregulation of Th1-type cytokines and elevation of the Th2-type cytokines (IL-4 and IL-10), mitigation of oxidative stress, modulation of mitogen-activated protein kinase signaling pathways and increasing Sarco-endoplasmic reticulum Ca²⁺-ATPase levels are among the most important anti-myocarditis mechanisms for the retrieved molecules and extracts. Interestingly, there are structural similarities between the anti-EAM compounds, suggesting the presence of similar pharmacophore and enzymatic targets for these molecules. Naturally occurring molecules discussed in the present article are potential anti-myocarditis drugs and future additional animal studies and clinical trials would shed more light on their effectiveness in the treatment of myocarditis and prevention of dilated cardiomyopathy.

Comparative evaluation of torasemide and spironolactone on adverse cardiac remodeling in a rat model of dilated cardiomyopathy

BACKGROUND

Chronic heart failure (CHF) involves fluid retention and volume overload, leading to impaired cardiac function. In these conditions, diuretic agents are most commonly used to treat edema and thereby reducing the volume load on the failing heart. There are several other beneficial effects of diuretics apart from their action on urinary excretion.

METHODS

To identify the effects of diuretic agents on adverse cardiac remodeling in CHF, this study was carried out, where we have compared the effects of torasemide and spironolactone in a rat model of dilated cardiomyopathy induced by porcine cardiac myosin-mediated experimental autoimmune myocarditis.

RESULTS

Cardiac protein expression levels of inflammation, endoplasmic reticulum stress, and fibrosis markers were upregulated in the hearts of CHF rats, while treatment with either torasemide or spironolactone has downregulated their expression. The effect produced by spironolactone on cardiac fibrosis markers was comparably lesser than torasemide. Further, immunohistochemical analysis and histopathological studies have provided evidence to confirm the beneficial effects of these drugs on adverse cardiac remodeling in rats with CHF.

CONCLUSION

Torasemide treatment has benefits against adverse cardiac remodeling in CHF rats, which was better than the protection offered by spironolactone.

Human umbilical cord mesenchymal stem cells alleviate acute myocarditis by modulating endoplasmic reticulum stress and extracellular signal regulated 1/2-mediated apoptosis

Acute myocarditis is a non-ischemic inflammatory disease of the myocardium, and there is currently no standard treatment. Mesenchymal stem cells (MSCs) can alleviate myosin‑induced myocarditis; however, the mechanism has not been clearly elucidated. In the present study, the authors investigated the ability of human umbilical cordMSCs (HuMSCs) to attenuate myocardial injury and dysfunction during the acute phase of experimental myocarditis. Male Lewis rats (aged 8 weeks) were injected with porcine myosin to induce myocarditis. Cultured HuMSCs (1x106 cells/rat) were intravenously injected 10 days following myosin injection. A total of 3 weeks following injection, this resulted in severe inflammation and significant deterioration of cardiac function. HuMSC transplantation attenuated infiltration of inflammatory cells and adverse cardiac remodeling, as well as reduced cardiomyocyte apoptosis. Furthermore, it was identified that HuMSC transplantation suppressed endoplasmic reticulum stress and extracellular signal‑regulated kinase (ERK)1/2 signaling in experimental autoimmune myocarditis (EAM). The reduced number of TUNEL‑positive apoptotic cells in myocardial sections from HuMSC‑treated EAM rats compared with control demonstrates HuMSCs' anti‑apoptotic function. Based on these data, the author suggested that treatment with HuMSCs inhibits myocardial apoptosis in EAM rats, ultimately protecting them from myocardial damage. The conclusion demonstrated that HuMSC transplantation attenuates myocardial injury and dysfunction in a rat model of acute myocarditis, potentially via regulation of ER stress, ERK1/2 signaling and induction of cardiomyocyte apoptosis.

Quercetin Inhibits Pulmonary Arterial Endothelial Cell Transdifferentiation Possibly by Akt and Erk1/2 Pathways

This study aimed to investigate the effects and mechanisms of quercetin on pulmonary arterial endothelial cell (PAEC) transdifferentiation into smooth muscle-like cells. TGF-β1-induced PAEC transdifferentiation models were applied to evaluate the pharmacological actions of quercetin. PAEC proliferation was detected with CCK8 method and BurdU immunocytochemistry. Meanwhile, the identification and transdifferentiation of PAECs were determined by FVIII immunofluorescence staining and α-SMA protein expression. The related mechanism was elucidated based on the levels of Akt and Erk1/2 signal pathways. As a result, quercetin effectively inhibited the TGF-β1-induced proliferation and transdifferentiation of the PAECs and activation of Akt/Erk1/2 cascade in the cells. In conclusion, quercetin is demonstrated to be effective for pulmonary arterial hypertension (PAH) probably by inhibiting endothelial transdifferentiation possibly via modulating Akt and Erk1/2 expressions.

Dissection of the Effects of Quercetin on Mouse Myocardium

Quercetin is a plant flavonoid with several biological activities. This study aimed to describe quercetin effects on contractile and electrophysiological properties of the cardiac muscle as well as on calcium handling. Quercetin elicited positive inotropism that was significantly reduced by propranolol indicating an involvement of the sympathetic nervous system. In cardiomyocytes, 30 μM quercetin increased I_Ca,L at 0 mV from -0.95 ± 0.01 A/F to -1.21 ± 0.08 A/F. The membrane potential at which 50% of the channels are activated (V_0.5 ) shifted towards more negative potentials from -13.06 ± 1.52 mV to -19.26 ± 1.72 mV and did not alter the slope factor. Furthermore, quercetin increased [Ca²⁺ ]_i transient by 28% when compared to control. Quercetin accelerated [Ca²⁺ ]_i transient decay time, which could be attributed to SERCA activation. In resting cardiomyocytes, quercetin did not change amplitude or frequency of Ca²⁺ sparks. In isolated heart, quercetin increased heart rate and decreased PRi, QTc and duration of the QRS complex. Thus, we showed that quercetin activates β-adrenoceptors, leading to increased L-type Ca²⁺ current and cell-wide intracellular Ca²⁺ transient without visible changes in Ca²⁺ sparks.

Original research paper. Pulmonary prophylactic impact of melatonin and/or quercetin: A novel therapy for inflammatory hypoxic stress in rats

The study aims to compare, through histological and biochemical studies, the effects of quercetin, melatonin and their combination in regulation of immuno-inflammatory mediators and heat shock protein expressions in sodium nitrite induced hypoxia in rat lungs. The results revealed that NaNO2 injection caused a significant decrease in Hb in rats, while serum levels of TNF-α, IL-6 and CRP, VEGF and HSP70 were elevated compared to the control group. Administration of melatonin, quercetin or their combination before NaNO2 injection markedly reduced these parameters. Histopathological examination of the lung tissue supported these biochemical findings. The study suggests that melatonin and/or quercetin are responsible for lung tissue protection in hypoxia by downregulation of immuno-inflammatory mediators and heat shock protein expressions. Pre-treatment of hypoxic animals with a combination of melatonin and quercetin was effective in modulating most of the studied parameters to near-normal levels.

Flavonols in the Prevention of Diabetes-induced Vascular Dysfunction

As flavonols are present in fruits and vegetables, they are consumed in considerable amounts in the diet. There is growing evidence that the well-recognized antioxidant, anti-inflammatory, and vasorelaxant actions of flavonols may, at least in part, result from modulation of biochemical signaling pathways and kinases. It is well established that diabetes is associated with increased cardiovascular morbidity and mortality. Despite clinical management of blood glucose levels, diabetes often results in cardiovascular disease. There is good evidence that endothelial dysfunction contributes significantly to the progression of diabetic cardiovascular diseases. This review describes the biological actions of flavonols that may ameliorate adverse cardiovascular events in diabetes. We discuss evidence that flavonols may be developed as novel pharmacological agents to prevent diabetes-induced vascular dysfunction.

Depletion of cardiac 14-3-3η protein adversely influences pathologic cardiac remodeling during myocardial infarction after coronary artery ligation in mice

BACKGROUND/OBJECTIVES

14-3-3η protein, a dimeric phosphoserine-binding protein, provides protection against adverse cardiac remodeling during pressure-overload induced heart failure in mice. To identify its role in myocardial infarction (MI), we have used mice with cardio-specific expression of dominant-negative 14-3-3η protein mutant (DN14-3-3) and performed the surgical ligation of left anterior descending coronary artery.

METHODS

We have performed echocardiography to assess cardiac function, protein expression analysis using Western blotting, mRNA expression by real time-reverse transcription polymerase chain reaction and histopathological analyses.

RESULTS

DN14-3-3 mice with MI displayed reduced survival, left ventricular ejection fraction and fractional shortening. Interestingly, DN14-3-3 mice subjected to MI showed increased cardiac hypertrophy, inflammation, fibrosis and apoptosis as compared to their wild-type counterparts. Mechanistically, DN14-3-3 mice with MI exhibited activation of endoplasmic reticulum (ER) stress and markers of maladaptive cardiac remodeling. Cardiac regeneration marker expression also decreased drastically in the DN14-3-3 mice with MI.

CONCLUSION

Depletion of the 14-3-3η protein causes cardiac dysfunction and reduces survival in mice with MI, probably via exacerbation of ER stress and death signaling pathways and suppression of cardiac regeneration. Thus, identification of drugs that can modulate cardiac 14-3-3η protein levels may probably provide a novel protective therapy for heart failure.

Effect of different doses of quercetin on pancreatic pathology in rats with hypertriglyceridemia related acute pancreatitis

AIM: To investigate the effect of different doses of quercetin on the pancreatic pathology in rats with cerulein-induced acute pancreatitis (AP) associated with hypertriglyceridemia (HTG).

METHODS: Seventy-two male SD rats were randomly divided into 12 groups: HTG group (n = 6, fed a high-fat diet for 2 wk: 77% normal chow + 3% cholesterol + 20% lard), HTG + AP group (n = 6, after 2 wk of a high-fat diet, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), HTG + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction], normal blood lipid group (n = 6, fed normal chow for 2 wk), normal blood lipid + AP group (n = 6, after 2 wk of normal chow, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), normal blood lipid + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction]. All rats were sacrificed 9 h after AP induction. Plasma levels of amylase were tested and the pathological changes of pancreatic tissues were observed.

RESULTS: After two weeks of a high-fat diet, serum levels of triglyceride and total cholesterol were much higher than those in rats given normal chow (P < 0.001). Compared with the normal blood lipid + AP group, plasma level of amylase was significantly higher (23670.00 U/L ± 2053.13 U/L vs 13136.00 U/L ± 3536.95 U/L) and pancreatic tissue injury was significantly more serious in the HTG + AP group (9.75 ± 0.94 vs 5.92 ± 1.32) (P = 0.022; P < 0.001). Quercetin intervention groups showed significantly lower levels of amylase and less serious pancreatic tissue injury; the effect was dose-dependent. This protective effect of quercetin was more obvious in the HTG + AP group than in the AP group (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group total histopathological scores: P < 0.001 for all; normal blood lipid + AP + 100, 150, 200 mg/kg quercetin group vs normal blood lipid + AP group total histopathological scores: P = 0.084, P = 0.003, P < 0.001), particularly in acinar necrosis and inflammatory infiltration (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group necrosis score: P < 0.001 for all; inflammatory infiltration: P = 0.008, P = 0.006, P = 0.001).

CONCLUSION: Quercetin could significantly ameliorate the pancreatic pathology in rats with HTG related AP, especially acinar necrosis and inflammatory infiltration. The protective effect is dose-dependent.

Cardioprotective Effect of Licochalcone D against Myocardial Ischemia/Reperfusion Injury in Langendorff-Perfused Rat Hearts

Flavonoids are important components of ‘functional foods’, with beneficial effects on cardiovascular function. The present study was designed to investigate whether licochalcone D (LD) could be a cardioprotective agent in ischemia/reperfusion (I/R) injury and to shed light on its possible mechanism. Compared with the I/R group, LD treatment enhanced myocardial function (increased LVDP, dp/dt_max, dp/dt_min, HR and CR) and suppressed cardiac injury (decreased LDH, CK and myocardial infarct size). Moreover, LD treatment reversed the I/R-induced cleavage of caspase-3 and PARP, resulting in a significant decrease in proinflammatory factors and an increase in antioxidant capacity in I/R myocardial tissue. The mechanisms underlying the antiapoptosis, antiinflammation and antioxidant effects were related to the activation of the AKT pathway and to the blockage of the NF-κB/p65 and p38 MAPK pathways in the I/R-injured heart. Additionally, LD treatment markedly activated endothelial nitric oxide synthase (eNOS) and reduced nitric oxide (NO) production. The findings indicated that LD had real cardioprotective potential and provided support for the use of LD in myocardial I/R injury.

A combination of methylprednisolone and quercetin is effective for the treatment of cardiac contusion following blunt chest trauma in rats

Cardiac contusion is a potentially fatal complication of blunt chest trauma. The effects of a combination of quercetin and methylprednisolone against trauma-induced cardiac contusion were studied. Thirty-five female Sprague-Dawley rats were divided into five groups (n=7) as follows: sham, cardiac contusion with no therapy, treated with methylprednisolone (30 mg/kg on the first day, and 3 mg/kg on the following days), treated with quercetin (50 mg·kg⁻¹·day⁻¹), and treated with a combination of methylprednisolone and quercetin. Serum troponin I (Tn-I) and tumor necrosis factor-alpha (TNF-α) levels and cardiac histopathological findings were evaluated. Tn-I and TNF-α levels were elevated after contusion (P=0.001 and P=0.001). Seven days later, Tn-I and TNF-α levels decreased in the rats treated with methylprednisolone, quercetin, and the combination of methylprednisolone and quercetin compared to the rats without therapy, but a statistical significance was found only with the combination therapy (P=0.001 and P=0.011, respectively). Histopathological degeneration and necrosis scores were statistically lower in the methylprednisolone and quercetin combination group compared to the group treated only with methylprednisolone (P=0.017 and P=0.007, respectively). However, only degeneration scores were lower in the combination therapy group compared to the group treated only with quercetin (P=0.017). Inducible nitric oxide synthase positivity scores were decreased in all treatment groups compared to the untreated groups (P=0.097, P=0.026, and P=0.004, respectively). We conclude that a combination of quercetin and methylprednisolone can be used for the specific treatment of cardiac contusion.

Klotho suppresses cardiomyocyte apoptosis in mice with stress-induced cardiac injury via downregulation of endoplasmic reticulum stress

Cardiomyocyte apoptosis is a common pathological alteration in heart disease which results in systolic dysfunction or sudden death. Klotho is a novel anti-aging hormone. We tested the effects of klotho on cell apoptosis in isoproterenol-treated cardiomyocytes. In BALB/c mice, cardiac injury was induced by subcutaneous injection of isoproterenol (5 mg/kg, for 9 days, s.c.). Klotho (0.01 mg/kg, every other day for 4 days, i.p.) was administered to determine the changes in isoproterenol-induced apoptosis. Mouse heart was harvested at day 2, day 5, and day 9 after isoproterenol injection. Isoproterenol induced cardiac apoptosis and endoplasmic reticulum (ER) stress in a time-dependent manner. However, klotho partly reversed isoproterenol-induced cardiac apoptosis and ER stress. These same effects were observed in cultured cardiomyocytes. Furthermore, the results also showed that SB203580, a p38 inhibitor, and SP600125, a c-Jun NH2-terminal kinase (JNK) inhibitor, reduced cardiomyocyte apoptosis and ER stress, however, klotho suppressed isoproterenol-induced activation of p38 and JNK. Taken together, these results indicated that cardioprotection by klotho was related to the attenuation of ER stress and ER stress-induced apoptosis, at least partly, through suppressing activation of the p38 and JNK pathway.

Anti-microbial and anti-oxidant activities of Illicium verum, Crataegus oxyacantha ssp monogyna and Allium cepa red and white varieties

Illicium verum (badiane or star anise), Crataegus oxyacantha ssp monogyna (hawthorn) and Allium cepa (onion), have traditionnally been used as medicinal plants in Algeria. This study showed that the outer layer of onion is rich in flavonols with contents of 103 ± 7.90 µg/g DW (red variety) and 17.3 ± 0.69 µg/gDW (white variety). We also determined flavonols contents of 14.3 ± 0.21 µg/g 1.65 ± 0.61 µg/g for Crataegus oxyacantha ssp monogyna leaves and berries and 2.37 ± 0.10 µg/g for Illicium verum. Quantitative analysis of anthocyanins showed highest content in Crataegus oxyacantha ssp monogyna berries (5.11 ± 0.266 mg/g), while, inner and outer layers of white onion had the lowest contents with 0.045 ± 0.003mg/g and 0.077 ± 0.001 mg/g respectively.   Flavonols extracts presented high antioxidant activity as compared with anthocyanins and standards antioxidants (ascorbic acid and quercetin). Allium cepa and Crataegus oxyacantha ssp monogyna exhibited the most effective antimicrobial activity.

Cardioprotective effects of different flavonoids against myocardial ischaemia/reperfusion injury in Langendorff-perfused rat hearts

OBJECTIVE

Flavonoids are important components of 'functional foods', with beneficial effects on the cardiovascular function, mainly due to their antioxidant activity. Many flavonoids exert antihypertensive, anti-atherosclerotic and antiplatelet activity and positive effects against endothelial dysfunction. Recent evidence indicates that they exert cardioprotective effects against myocardial ischaemia/reperfusion (I/R) injury. The aim of this work was to investigate these properties for flavonoids with different structural characteristics.

METHODS

In this work, the cardioprotective effects of eight flavonoids endowed with different structural characteristics were tested on Langendorff-perfused rat hearts submitted to 30 min of global ischaemia followed by 120 min of reperfusion (I/R).

KEY FINDINGS

Only the 5-hydroxy-substituted derivatives, such as 5-hydroxy flavone, apigenin, chrysin and naringenin, conferred on the hearts an improved post-ischaemic functional recovery associated with lower extension of tissue injury. A similar pharmacological profile was exhibited by 5-methoxy flavone. In contrast, 6-hydroxy flavone, 7-hydroxy flavone and 4'-hydroxy flavanone did not confer significant protection against the injury induced by I/R.

CONCLUSIONS

Some flavonoids exhibit direct cardioprotective effects against the injury induced by drastic I/R and this pharmacological property seems to be related to their structural characteristics. Such an influence of structural requirements seems to indicate that the cardioprotective effects may be due to the interaction with specific pharmacological targets.

Protective effect of quercetin on lead-induced oxidative stress and endoplasmic reticulum stress in rat liver via the IRE1/JNK and PI3K/Akt pathway

Lead (Pb), a well-known environmental toxin, is one of the major hazards for human health. Quercetin (QE), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against Pb-induced endoplasmic reticulum (ER) stress in liver have not been clarified. The aim of the present study was to investigate the effects of quercetin on hepatic ER stress in rats exposed to Pb. Wistar rats were exposed to lead acetate in the drinking water with or without quercetin co-administration for 75 days. Our data showed that quercetin significantly prevented Pb-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage and histopathological analysis. Quercetin markedly decreased Pb contents in blood and liver. Western blot analysis showed that Pb-induced ER stress in rat liver was significantly inhibited by quercetin. In exploring the underlying mechanisms of quercetin action, we found quercetin markedly suppressed Pb-induced oxidative stress. Quercetin decreased reactive oxygen species (ROS) production and increased the total antioxidant capacity in rat livers. Additionally, quercetin dramatically increased Phosphoinositide-3-kinase (PI3K) and phosphorylated protein kinase B (PKB/Akt) levels in liver rats. In the examined unfolded protein response (UPR) pathways, quercetin markedly inhibited the Pb-induced increase of the phosphorylated inositol-requiring enzyme 1 (IRE1) and c-jun N-terminal kinase (JNK) in rat liver. Taken together, these results suggested that the inhibition of Pb-induced ER stress by quercetin is due at least in part to its anti-oxidant stress activity and its ability to modulate the PI3K/Akt and IRE1/JNK signaling pathway.