Fisetin inhibits cardiac hypertrophy by suppressing oxidative stress

Combined diosmin and bisoprolol attenuate cobalt chloride-induced cardiotoxicity and endothelial dysfunction through modulating miR-143-3P/MAPK/MCP-1, ERK5/CXCR4, Orai-1/STIM-1 signaling pathways

Even while accelerated cardiomyocyte apoptosis is one of the primary causes of cardiac damage, the underlying mechanism is still mostly unknown. In addition to examining potential protective effects of bisoprolol and diosmin against CoCl2-induced cardiac injury, the goal of this study was to identify potential mechanisms regulating the hypoxic cardiac damage caused by cobalt chloride (CoCl2). For a period of 21 days except Cocl2 14 days from the first day of the experiment, rats were split into the following groups: Normal control group, rats received vehicle only (2 ml/kg/day, p.o.), (Cocl2, 150 mg/kg/day, p.o.), bisoprolol (25 mg/kg/day, p.o.); diosmin (100 mg/kg/day, p.o.) and bisoprolol + diosmin + Cocl2 groups. At the end of the experimental period, serum was taken for estimation of cardiac function, lipid profile, and pro/anti-inflammatory cytokines. Moreover, tissue samples were collected for evaluation of oxidative stress, endothelial dysfunction, α-SMA, PKC-α, MiR-143-3P, MAPK, ERK5, MCP-1, CXCR4, Orai-1, and STIM-1. Diosmin and bisoprolol, either alone or in combination, enhance heart function by reducing abnormalities in the electrocardiogram and the hypotension brought on by CoCl2. Additionally, they significantly ameliorate endothelial dysfunction by downregulating the cardiac expressions of α-SMA, PKC-α, MiR-143-3P, MAPK, ERK5, MCP-1, CXCR4, Orai-1, and STIM-1. Bisoprolol and diosmin produced modulatory activity against inflammatory state, redox balance, and atherogenic index concurrently. Together, diosmin and bisoprolol, either alone or in combination, significantly reduced all the cardiac alterations brought on by CoCl2. The capacity to obstruct hypoxia-induced α-SMA, PKC-α, MiR-143-3P/MAPK/MCP-1, MiR-143-3P/ERK5/CXCR4, Orai-1/STIM-1 signaling activation, as well as their anti-inflammatory, antioxidant, and anti-apoptotic properties, may be responsible for these cardio-protective results.

Fisetin ameliorates polycystic ovary syndrome in rats via a mechanistic modulation of AMP-activated protein kinase and SIRT1 molecular pathway

Fisetin, a polyphenolic flavonoid, exhibits numerous pharmacological activities against metabolic syndromes. The present research aims to explore the therapeutic efficacy of fisetin in experimental polycystic ovary syndrome (PCOS). Female Sprague-Dawley rats were administered mifepristone (20 mg/kg/day) to induce PCOS. PCOS rats were treated with fisetin (20 mg/kg and 40 mg/kg) and further compared with metformin HCl, the conventional drug for PCOS. The mechanism of fisetin was explored using dorsomorphin (an AMPK inhibitor). Then, rats were sacrificed for further analysis of biochemical and histological parameters. PCOS rats exhibited irregular estrous cycles, increased serum testosterone (4.72 ± 0.139 ng/ml), estradiol (750.2 ± 16.56 pg/ml), LH (30.33 ± 1.563 mIU/ml), HOMA-IR (1.115 ± 0.049), TNF-α (86.59 ± 3.93 pg/ml), IL-6 (55.34 ± 4.432 pg/ml), and TBARS (3.867 ± 0.193 µmol/mg) along with declined progesterone (11.67 ± 1.54 ng/ml), FSH (13.33 ± 1.256 mIU/ml), GSH (33.47 ± 1.348 µmol/mg) levels, and SOD (2.163 ± 0.298 U/mg) activity as compared to normal control group. Fisetin high dose significantly lowers testosterone (3.014 ± 0.234 ng/ml), estradiol (533.7 ± 15.39 pg/ml), LH (16.67 ± 1.62 mIU/ml), HOMA-IR (0.339 ± 0.20), TNF-α (46.02 ± 2.66 pg/ml), IL-6 (31.77 ± 3.47 pg/ml), and TBARS (1.747 ± 0.185 µmol/mg) and enhances progesterone (33.17 ± 1.447 ng/ml), FSH (27.17 ± 1.42 mIU/ml), GSH (60.35 ± 1.1.102 µmol/mg) levels, and SOD (4.513 ± 0.607 U/mg) activity. The histology of ovarian tissues shows a significant increase in cystic follicles in PCOS rats compared with the normal control group. These alterations were attenuated with fisetin treatment. Administration of dorsomorphin with fisetin can reverse the beneficial effects of fisetin in PCOS rats. Altogether, these present findings highlight the potential of fisetin as a promising therapeutic intervention for the management of PCOS by modulating AMPK/SIRT1 signaling in rats.

miR-338-5p regulated the NF-κB/MAPK pathway to alleviate inflammation and oxidative stress by targeting IL-6 in rats with atrial fibrillation

The aim of this study was to investigate the functional effect of miR-338-5p targeting IL-6 on NF-κB/MAPK pathway-mediated inflammation and oxidative stress in atrial fibrillation (AF) rats. AF model rats were generated by tail vein injection of 0.1 mL Ach-CaCl2 mixture. The overexpression and suppression of miR-338-5p were established by injecting a miR-338-5p-agomir and a miR-338-5p-antagomir, respectively, into AF rats. Cardiac morphological changes were detected by H&E and Masson staining. The levels of ROS, SOD, T-AOC, IL-6, IL-1β, and TNF-α were detected via ELISA. Dual luciferase assays, qRT‒PCR, and western blotting were used to verify that miR-338-5p targets IL-6. The expression of NF-κB/MAPK pathway proteins was detected by western blot. Overexpression of miR-338-5p ameliorated heart damage in AF rats. Increased miR-338-5p reduced the levels of CK, CK-MB, and cTnT to alleviate myocardial injury. Furthermore, overexpression of miR-338-5p relieved inflammation and oxidative stress by downregulating SOD and T-AOC and upregulating IL-6, IL-1β, TNF-α, and ROS. Further research revealed that upregulation of miR-338-5p reduced the protein levels of p-p38, p-p65 and p-ERK1/2. The opposite results were obtained following miR-338-5p-antagomir treatment. Taken together, these findings indicate that the upregulation of miR-338-5p alleviated inflammation and oxidative stress by targeting IL-6 to inhibit the NF-κB/MAPK pathway, thus providing a new therapeutic target for AF.

Fisetin nanoparticles based on cells cycle and apoptosis intervention for the treatment of lymphoma and leukemia

Lymphoma and leukemia are both hematological system tumors with complex etiology, and mainly treated with chemotherapeutic drugs. However, therapeutic drugs can interrupt curative effect due to different side effects. Therefore, it is worthwhile to develop a novel therapeutic for providing insights for clinical tumor treatment. In this study, we developed a fisetin nanoparticles (Fisetin NPs) through a self-assembled method, and investigated the activity and potential mechanism of Fisetin NPs against lymphoma and leukemia. The spherical and uniformly distributed Fisetin NPs effectively inhibited both tumor cells proliferation, arrested EL4 cells G0/G1 phase and K562 cells G2/M phase, and induced apoptosis in vitro. In vivo, Fisetin NPs exhibited excellent tumor growth inhibition, effective inhibition of cell proliferation and angiogenesis, significant induction of apoptosis and ideal safety. Mechanically, fisetin upregulated genes (Fas, Pidd, Puma, Apaf1, and p21) in the p53 signaling pathway and bound to N-acetyltransferase 10 (NAT10), ribosomal protein L34 (RPL34) and GTP binding protein 4 (GTPBP4). Collectively, Fisetin NPs have promising therapeutic effects on lymphoma and leukemia, which are of great significant for clinical implications.

Tannic acid may ameliorate doxorubicin-induced changes in oxidative stress parameters in rat spleen

Doxorubicin (DOX) is a potent and broad-spectrum drug widely used in the treatment of cancer. However, the toxicity and side effects of DOX on various organs limit its clinical use. Approaches using natural antioxidants with these drugs have the potential to alleviate negative side effects. The aim of this study was to investigate the potential protective effect of tannic acid, a polyphenolic compound found naturally in plants, against DOX-induced spleen toxicity. Expression levels of Alox5, Inos, IL-6, Tnf-α, Casp-3, Bax, SOD, GST, CAT and GPx genes were determined using cDNAs obtained from spleen tissues of rats treated with DOX, tannic acid and both. In addition, SOD, CAT, GPx and GST enzyme activities, and GSH and MDA levels were measured in tissues. In the spleen tissues, DOX caused a decrease in the level of GSH and an increase in the level of MDA. In addition, it was determined that DOX had a suppressive effect on CAT, GST, SOD and GPx mRNA levels and its enzyme activities, which are antioxidant system components. The mRNA expression levels of proinflammatory cytokine markers, apoptotic genes, and some factors involved in cell metabolism showed a change compared to the control after DOX application. However, as a result of tannic acid treatment with DOX, these changes approached the values of the control group. The findings showed that tannic acid had a protective effect on the changes in the oxidative stress and inflammation system in the rat spleen as a result of the application of tannic acid together with DOX.

NLRP3 inhibitors: Unleashing their therapeutic potential against inflammatory diseases

The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome has been linked to the release of pro-inflammatory cytokines and is essential for innate defence against infection and danger signals. These secreted cytokines improve the inflammatory response caused by tissue damage and associated inflammation. Consequently, the development of NLRP3 inflammasome inhibitors are viable option for the treatment of diverse inflammatory disorders. The significant anti-inflammatory effects of the NLRP3 inhibitors have severe side effects. Hence, the application of NLRP3 inhibitors against inflammatory disease has not yet been understood and most of the developed inhibitors are unsuccessful in clinical trials. The processes behind the NLRP3 complex, priming, and activation are the main emphasis of this review, which also covers therapeutical inhibitors of the NLRP3 inflammasome and potential therapeutic strategies for directing the NLRP3 inflammasome towards clinical development.

Fisetin attenuates doxorubicin-induced cardiotoxicity by inhibiting the insulin-like growth factor II receptor apoptotic pathway through estrogen receptor-α/-β activation

Doxorubicin (DOX), an effective chemotherapeutic drug, has been used to treat various cancers; however, its cardiotoxic side effects restrict its therapeutic efficacy. Fisetin, a flavonoid phytoestrogen derived from a range of fruits and vegetables, has been reported to exert cardioprotective effects against DOX-induced cardiotoxicity; however, the underlying mechanisms remain unclear. This study investigated fisetin's cardioprotective role and mechanism against DOX-induced cardiotoxicity in H9c2 cardiomyoblasts and ovariectomized (OVX) rat models. MTT assay revealed that fisetin treatment noticeably rescued DOX-induced cell death in a dose-dependent manner. Moreover, western blotting and TUNEL-DAPI staining showed that fisetin significantly attenuated DOX-induced cardiotoxicity in vitro and in vivo by inhibiting the insulin-like growth factor II receptor (IGF-IIR) apoptotic pathway through estrogen receptor (ER)-α/-β activation. The echocardiography, biochemical assay, and H&E staining results demonstrated that fisetin reduced DOX-induced cardiotoxicity by alleviating cardiac dysfunction, myocardial injury, oxidative stress, and histopathological damage. These findings imply that fisetin has a significant therapeutic potential against DOX-induced cardiotoxicity.

Effects of Fisetin Treatment on Cellular Senescence of Various Tissues and Organs of Old Sheep

Fisetin has been shown to be beneficial for brain injury and age-related brain disease via different mechanisms. The purpose of this study was to determine the presence of senescent cells and the effects of fisetin on cellular senescence in the brain and other vital organs in old sheep, a more translational model. Female sheep 6-7 years old (N = 6) were treated with 100 mg/kg fisetin or vehicle alone on two consecutive days a week for 8 weeks. All vital organs were harvested at the time of sacrifice. Histology, immunofluorescence staining, and RT-Q-PCR were performed on different regions of brain tissues and other organs. Our results indicated that fisetin treatment at the current regimen did not affect the general morphology of the brain. The presence of senescent cells in both the cerebral brain cortex and cerebellum and non-Cornu Ammonis (CA) area of the hippocampus was detected by senescent-associated β-galactosidase (SA-β-Gal) staining and GL13 (lipofuscin) staining. The senescent cells detected were mainly neurons in both gray and white matter of either the cerebral brain cortex, cerebellum, or non-CA area of the hippocampus. Very few senescent cells were detected in the neurons of the CA1-4 area of the hippocampus, as revealed by GL13 staining and GLB1 colocalization with NEUN. Fisetin treatment significantly decreased the number of SA-β-Gal+ cells in brain cortex white matter and GL13+ cells in the non-CA area of the hippocampus, and showed a decreasing trend of SA-β-Gal+ cells in the gray matter of both the cerebral brain cortex and cerebellum. Furthermore, fisetin treatment significantly decreased P16+ and GLB1+ cells in neuronal nuclear protein (NEUN)+ neurons, glial fibrillary acidic protein (GFAP)+ astrocytes, and ionized calcium binding adaptor molecule 1 (IBA1)+ microglia cells in both gray and white matter of cerebral brain cortex. Fisetin treatment significantly decreased GLB1+ cells in microglia cells, astrocytes, and NEUN+ neurons in the non-CA area of the hippocampus. Fisetin treatment significantly decreased plasma S100B. At the mRNA level, fisetin significantly downregulated GLB1 in the liver, showed a decreasing trend in GLB1 in the lung, heart, and spleen tissues, and significantly decreased P21 expression in the liver and lung. Fisetin treatment significantly decreased TREM2 in the lung tissues and showed a trend of downregulation in the liver, spleen, and heart. A significant decrease in NRLP3 in the liver was observed after fisetin treatment. Finally, fisetin treatment significantly downregulated SOD1 in the liver and spleen while upregulating CAT in the spleen. In conclusion, we found that senescent cells were widely present in the cerebral brain cortex and cerebellum and non-CA area of the hippocampus of old sheep. Fisetin treatment significantly decreased senescent neurons, astrocytes, and microglia in both gray and white matter of the cerebral brain cortex and non-CA area of the hippocampus. In addition, fisetin treatment decreased senescent gene expressions and inflammasomes in other organs, such as the lung and the liver. Fisetin treatment represents a promising therapeutic strategy for age-related diseases.

Fisetin Delays Postovulatory Oocyte Aging by Regulating Oxidative Stress and Mitochondrial Function through Sirt1 Pathway

The quality of oocytes determines the development potential of an embryo and is dependent on their timely fertilization after ovulation. Postovulatory oocyte aging is an inevitable factor during some assisted reproduction technology procedures, which results in poor fertilization rates and impairs embryo development. We found that fisetin, a bioactive flavonol contained in fruits and vegetables, delayed postovulatory oocyte aging in mice. Fisetin improved the development of aged oocytes after fertilization and inhibited the Sirt1 reduction in aged oocytes. Fisetin increased the GSH level and Sod2 transcription level to inhibit ROS accumulation in aged oocytes. Meanwhile, fisetin attenuated aging-induced spindle abnormalities, mitochondrial dysfunction, and apoptosis. At the molecular level, fisetin decreased aging-induced aberrant expression of H3K9me3. In addition, fisetin increased the expression levels of the mitochondrial transcription factor Tfam and the mitochondrial genes Co2 and Atp8 by upregulating Sirt1 in aged oocytes. Finally, inhibition of Sirt1 reversed the anti-aging effects of fisetin. Taken together, fisetin delayed postovulatory oocyte aging by upregulating Sirt1.

Natural products in attenuating renal inflammation via inhibiting the NLRP3 inflammasome in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and severe complications of diabetes and serves as the primary cause of end-stage kidney disease (ESKD) globally. Increasing evidence indicates that renal inflammation is critical in the pathogenesis of DKD. The nucleotide - binding oligomerization domain (NOD) - like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most extensively researched inflammasome complex and is considered a crucial regulator in the pathogenesis of DKD. The activation of NLRP3 inflammasome is regulated by various signaling pathways, including NF- κB, thioredoxin-interacting protein (TXNIP), and non-coding RNAs (ncRNA), among others. Natural products are chemicals extracted from living organisms in nature, and they typically possess pharmacological and biological activities. They are invaluable sources for drug design and development. Research has demonstrated that many natural products can alleviate DKD by targeting the NLRP3 inflammasome. In this review, we highlight the role of the NLRP3 inflammasome in DKD, and the pathways by which natural products fight against DKD via inhibiting the NLRP3 inflammasome activation, so as to provide novel insights for the treatment of DKD.

Parkia speciosa Hassk. Empty Pod Extract Prevents Cardiomyocyte Hypertrophy by Inhibiting MAPK and Calcineurin-NFATC3 Signaling Pathways

Cardiac hypertrophy is an early hallmark during the clinical course of heart failure. Therapeutic strategies aiming to alleviate cardiac hypertrophy via the mitogen-activated protein kinase (MAPK)/calcineurin-nuclear factor of activated T-cells (NFAT) signaling pathway may help prevent cardiac dysfunction. Previously, empty pod ethanol crude extract of Parkia speciosa Hassk was shown to demonstrate protective effects against cardiomyocyte hypertrophy. Therefore, the current study aimed to investigate the effects of various fractions of the plant ethanol extract on the MAPK/NFAT signaling pathway in angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. Simultaneous treatment with ethyl acetate (EA) fraction produced the most potent antihypertrophic effect evidenced by the reduced release of B-type natriuretic peptide (BNP). Subsequently, treatment with the EA fraction (6.25, 12.5, and 25 μg/mL) prevented an Ang II-induced increase in cell surface area, hypertrophic factors (atrial natriuretic peptide and BNP), reactive oxygen species, protein content, and NADPH oxidase 4 expression in the cells. Furthermore, EA treatment attenuated the activation of the MAPK pathway and calcineurin-related pathway (GATA-binding protein 4 and NFATC3), which was similar to the effects of valsartan (positive control). Our findings indicate that the EA fraction prevents Ang II-induced cardiac hypertrophy by regulating the MAPK/calcineurin-NFAT signaling pathway.

New Progress in the Molecular Regulations and Therapeutic Applications in Cardiac Oxidative Damage Caused by Pressure Overload

Chronic pressure overload is a key risk factor for mortality due to its subsequent development of heart failure, in which the underlying molecular mechanisms remain vastly undetermined. In this review, we updated the latest advancements for investigating the role and relevant mechanisms of oxidative stress involved in the pathogenesis of pressure-overload-induced cardiomyopathy and cardiac dysfunction, focusing on significant biological sources of reactive oxygen species (free radical) production, antioxidant defenses, and their association with the cardiac metabolic remodeling in the stressed heart. We also summarize the newly developed preclinical therapeutic approaches in animal models for pressure-overload-induced myocardial damage. This review aims to enhance the current understanding of the mechanisms of chronic hypertensive heart failure and potentially improve the development of better therapeutic strategies for the associated diseases.

Hydrogen Attenuates Thyroid Hormone-Induced Cardiac Hypertrophy in Rats by regulating angiotensin II type 1 receptor and NADPH oxidase 2 mediated oxidative stress

Cardiac hypertrophy occurs as a result of high levels of thyroid hormone, which may contribute to heart failure and is closely related to oxidative stress. Hydrogen is a good antioxidant. In this study, we found that intragastric levothyroxine administration for two weeks caused obvious cardiac hypertrophy without reduced systolic function. Additionally, hydrogen inhalation ameliorated the levothyroxine-induced metabolic increase and cardiac hypertrophy in rats. Serum brain natriuretic peptide expression was also attenuated by hydrogen treatment. However, hydrogen had no significant effect on levothyroxine -induced serum troponin I and serum thyroid hormone changes. Hydrogen treatment also reduced the levothyroxine-induced increase in cardiac malondialdehyde, 8-hydroxy-2-deoxyguanosine and serum hydrogen peroxide levels and upregulated superoxide dismutase and glutathione peroxidase activity. Additionally, western blotting results showed that hydrogen inhalation inhibited the expression of cardiac nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2), angiotensin II type 1 receptor, sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2), phospho-phospholamban and α-myosin heavy chain proteins. In conclusion, the present study revealed a protective effect of hydrogen on levothyroxine -induced cardiac hypertrophy by regulating angiotensin II type 1 receptors and NOX2-mediated oxidative stress in rats.

Fisetin Attenuates Doxorubicin-Induced Cardiomyopathy In Vivo and In Vitro by Inhibiting Ferroptosis Through SIRT1/Nrf2 Signaling Pathway Activation

Doxorubicin (DOX) is an anthracycline antibiotic that is used extensively for the management of carcinoma; however, its clinical application is limited due to its serious cardiotoxic side effects. Ferroptosis represents iron-dependent and reactive oxygen species (ROS)-related cell death and has been proven to contribute to the progression of DOX-induced cardiomyopathy. Fisetin is a natural flavonoid that is abundantly present in fruits and vegetables. It has been reported to exert cardioprotective effects against DOX-induced cardiotoxicity in experimental rats. However, the underlying mechanisms remain unknown. The present study investigated the cardioprotective role of fisetin and the underlying molecular mechanism through experiments in the DOX-induced cardiomyopathy rat and H9c2 cell models. The results revealed that fisetin treatment could markedly abate DOX-induced cardiotoxicity by alleviating cardiac dysfunction, ameliorating myocardial fibrosis, mitigating cardiac hypertrophy in rats, and attenuating ferroptosis of cardiomyocytes by reversing the decline in the GPX4 level. Mechanistically, fisetin exerted its antioxidant effect by reducing the MDA and lipid ROS levels and increasing the glutathione (GSH) level. Moreover, fisetin exerted its protective effect by increasing the SIRT1 expression and the Nrf2 mRNA and protein levels and its nuclear translocation, which resulted in the activation of its downstream genes such as HO-1 and FTH1. Selective inhibition of SIRT1 attenuated the protective effects of fisetin in the H9c2 cells, which in turn decreased the GSH and GPX4 levels, as well as Nrf2, HO-1, and FTH1 expressions. In conclusion, fisetin exerts its therapeutic effects against DOX-induced cardiomyopathy by inhibiting ferroptosis via SIRT1/Nrf2 signaling pathway activation.

Fisetin Attenuates Diabetic Nephropathy-Induced Podocyte Injury by Inhibiting NLRP3 Inflammasome

Diabetic nephropathy (DN) is one of the primary complications of diabetes. Fisetin is a flavonoid polyphenol that is present in several vegetables and fruits. The present study investigated the mechanisms of fisetin in DN-induced podocyte injury both in vitro and in vivo. The results revealed that fisetin ameliorated high glucose (HG)-induced podocyte injury and streptozotocin (STZ)-induced DN in mice. CDKN1B mRNA expression in the glomeruli of patients with DN decreased based on the Nephroseq dataset, and fisetin reversed CDKN1B expression at mRNA and protein levels in a dose-dependent manner in podocytes and mice kidney tissues. Furthermore, fisetin suppressed the phosphorylation of P70S6K, a downstream target of CDKN1B, activated autophagosome formation, and inhibited Nod-like receptor protein 3 (NLRP3) inflammasomes. Interfering CDKN1B reduced the protective effects of fisetin against high glucose-induced podocyte injury. Molecular docking results revealed a potential interaction between fisetin and CDKN1B. In summary, the present study revealed that fisetin alleviated high glucose-induced podocyte injury and STZ-induced DN in mice by restoring autophagy-mediated CDKN1B/P70S6K pathway and inhibiting NLRP3 inflammasome.

Fisetin Ameliorates Alcohol-Induced Liver Injury through Regulating SIRT1 and SphK1 Pathway

Alcoholic liver disease (ALD) often leads to hepatitis, hepatic cirrhosis, and even hepatocellular carcinoma. Fisetin has been shown to confer protection against liver injury. Herein, we investigated whether fisetin could prevent ethanol-induced hepatotoxicity. Mice were fed on 5% (v/v) Lieber–DeCarli ethanol diet. Human primary hepatic stellate cells (HSCs) co-cultured with ethanol were used to verify the therapeutic effect of fisetin. The results of alanine/aspartate aminotransferase (ALT/AST), Triglyceride (TG), total cholesterol (TC) in serum, Oil O Red and Masson staining revealed that fisetin (80[Formula: see text]mg/kg) ameliorated ethanol-induced mice liver injury and fibrosis. Besides, immunofluorescence results of [Formula: see text]-SMA revealed that fisetin suppressed HSCs activation. The suppression was dose-dependent. Furthermore, fisetin promoted SIRT1-mediated autophagy and inhibited Sphk1-mediated endoplasmic reticulum stress (ER stress) both in vitro and in vivo. Molecular docking results indicated potential interaction of fisetin with SIRT1 and SphK1. The inhibitory effect of fisetin on HSCs activation was reversed on co-culturing with EX-527, a specific inhibitor against STIR1 overexpression. Thus, fisetin has the potential to ameliorate alcohol-induced liver injury through suppression of HSCs activation, SIRT1-mediated autophagy and Sphk1-mediated ER stress.

Dioscin Attenuates Myocardial Ischemic/Reperfusion-Induced Cardiac Dysfunction through Suppression of Reactive Oxygen Species

Myocardial ischemic/reperfusion (MI/R) is a leading cause of cardiovascular disease with high morbidity and mortality. However, the mechanisms underlying pathological reperfusion remain obscure. In this study, we found that dioscin, a natural product, could be a potential candidate for treating MI/R through modulating cardiac dysfunction. Mechanistically, our work revealed that dioscin could suppress the production of reactive oxygen species (ROS) via repressing the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2) and enhancing the expression of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx). These findings indicate that dioscin may be a potential candidate for therapeutic interventions in MI/R injury.

Beta3-Adrenergic Receptor Activation Alleviates Cardiac Dysfunction in Cardiac Hypertrophy by Regulating Oxidative Stress

BACKGROUND

Excessive myocardial oxidative stress could lead to the congestive heart failure. NADPH oxidase is involved in the pathological process of left ventricular (LV) remodeling and dysfunction. β3-Adrenergic receptor (AR) could regulate cardiac dysfunction proved by recent researches. The molecular mechanism of β3-AR regulating oxidative stress, especially NADPH oxidase, remains to be determined.

METHODS

Cardiac hypertrophy was constructed by the transverse aortic constriction (TAC) model. ROS and NADPH oxidase subunits expression were assessed after β3-AR agonist (BRL) or inhibitor (SR) administration in cardiac hypertrophy. Moreover, the cardiac function, fibrosis, heart size, oxidative stress, and cardiomyocytes apoptosis were also detected.

RESULTS

β3-AR activation significantly alleviated cardiac hypertrophy and remodeling in pressure-overloaded mice. β3-AR stimulation also improved heart function and reduced cardiomyocytes apoptosis, oxidative stress, and fibrosis. Meanwhile, β3-AR stimulation inhibited superoxide anion production and decreased NADPH oxidase activity. Furthermore, BRL treatment increased the neuronal NOS (nNOS) expression in cardiac hypertrophy.

CONCLUSION

β3-AR stimulation alleviated cardiac dysfunction and reduced cardiomyocytes apoptosis, oxidative stress, and fibrosis by inhibiting NADPH oxidases. In addition, the protective effect of β3-AR is largely attributed to nNOS activation in cardiac hypertrophy.

Anti-aging: senolytics or gerostatics (unconventional view)

Senolytics are basically anti-cancer drugs, repurposed to kill senescent cells selectively. It is even more difficult to selectively kill senescent cells than to kill cancer cells. Based on lessons of cancer therapy, here I suggest how to exploit oncogene-addiction and to combine drugs to achieve selectivity. However, even if selective senolytic combinations will be developed, there is little evidence that a few senescent cells are responsible for organismal aging. I also discuss gerostatics, such as rapamycin and other rapalogs, pan-mTOR inhibitors, dual PI3K/mTOR inhibitors, which inhibit growth- and aging-promoting pathways. Unlike senolytics, gerostatics do not kill cells but slow down cellular geroconversion to senescence. Numerous studies demonstrated that inhibition of the mTOR pathways by any means (genetic, pharmacological and dietary) extends lifespan. Currently, only two studies demonstrated that senolytics (fisetin and a combination Dasatinib plus Quercetin) extend lifespan in mice. These senolytics slightly inhibit the mTOR pathway. Thus, life extension by these senolytics can be explained by their slight rapamycin-like (gerostatic) effects.

Wogonin Inhibits Cardiac Hypertrophy by Activating Nrf-2-Mediated Antioxidant Responses

Background

Cardiac hypertrophy is one of the initial disorders of the cardiovascular system and can induce heart failure. Oxidative stress is an important pathophysiological mechanism of cardiac hypertrophy. Wogonin (Wog), an important flavonoid derived from the root of Scutellaria baicalensis Georgi, is known to possess antioxidant properties.

Methods

An in vitro model of cardiac hypertrophy was established by stimulating H9C2 cells and neonatal rat cardiomyocytes (NRCMs) with angiotensin II (AngII). The indices related to myocardial hypertrophy and oxidative stress were detected. An in vivo model of cardiac hypertrophy was induced by transverse aortic constriction (TAC) in C57BL/6 mice. Cardiac function was monitored by chest echocardiography, and the hypertrophy index was measured. The mice were then sacrificed for histological assays, with mRNA and protein detection. To further explore the role of nuclear factor- (erythroid-derived 2-) like 2 (Nrf-2) in regulating the antioxidant effects of Wog in cardiac hypertrophy, siRNA analysis was conducted.

Results

Our results showed that Wog significantly ameliorated AngII-induced cardiomyocyte hypertrophy by inhibiting oxidative stress in H9C2 cells and NRCMs. In addition, Wog treatment prevented oxidative stress and improved cardiac hypertrophy in mice that underwent TAC. Using gene-specific siRNA for Nrf-2, we discovered that these antioxidative effects of Wog are mediated through Nrf-2 induction.

Conclusions

Our results provide further evidence for the potential use of Wog as an antioxidative agent for treatment of cardiac hypertrophy, and Nrf-2 might serve as a therapeutic target in the treatment of cardiac hypertrophy.

Oxidative stress in cardiac hypertrophy: From molecular mechanisms to novel therapeutic targets

When faced with increased workload the heart undergoes remodelling, where it increases its muscle mass in an attempt to preserve normal function. This is referred to as cardiac hypertrophy and if sustained, can lead to impaired contractile function. Experimental evidence supports oxidative stress as a critical inducer of both genetic and acquired forms of cardiac hypertrophy, a finding which is reinforced by elevated levels of circulating oxidative stress markers in patients with cardiac hypertrophy. These observations formed the basis for using antioxidants as a therapeutic means to attenuate cardiac hypertrophy and improve clinical outcomes. However, the use of antioxidant therapies in the clinical setting has been associated with inconsistent results, despite antioxidants having been shown to exert protection in several animal models of cardiac hypertrophy. This has forced us to revaluate the mechanisms, both upstream and downstream of oxidative stress, where recent studies demonstrate that apart from conventional mediators of oxidative stress, metabolic disturbances, mitochondrial dysfunction and inflammation as well as dysregulated autophagy and protein homeostasis contribute to disease pathophysiology through mechanisms involving oxidative stress. Importantly, novel therapeutic targets have been identified to counteract oxidative stress and attenuate cardiac hypertrophy but more interestingly, the repurposing of drugs commonly used to treat metabolic disorders, hypertension, peripheral vascular disease, sleep disorders and arthritis have also been shown to improve cardiac function through suppression of oxidative stress. Here, we review the latest literature on these novel mechanisms and intervention strategies with the aim of better understanding the complexities of oxidative stress for more precise targeted therapeutic approaches to prevent cardiac hypertrophy.

The Anti-Inflammatory Properties of Phytochemicals and Their Effects on Epigenetic Mechanisms Involved in TLR4/NF-κB-Mediated Inflammation

Innate immune response induces positive inflammatory transducers and regulators in order to attack pathogens, while simultaneously negative signaling regulators are transcribed to maintain innate immune homeostasis and to avoid persistent inflammatory immune responses. The gene expression of many of these regulators is controlled by different epigenetic modifications. The remarkable impact of epigenetic changes in inducing or suppressing inflammatory signaling is being increasingly recognized. Several studies have highlighted the interplay of histone modification, DNA methylation, and post-transcriptional miRNA-mediated modifications in inflammatory diseases, and inflammation-mediated tumorigenesis. Targeting these epigenetic alterations affords the opportunity of attenuating different inflammatory dysregulations. In this regard, many studies have identified the significant anti-inflammatory properties of distinct naturally-derived phytochemicals, and revealed their regulatory capacity. In the current review, we demonstrate the signaling cascade during the immune response and the epigenetic modifications that take place during inflammation. Moreover, we also provide an updated overview of phytochemicals that target these mechanisms in macrophages and other experimental models, and go on to illustrate the effects of these phytochemicals in regulating epigenetic mechanisms and attenuating aberrant inflammation.

The Emerging Roles of Antioxidant Enzymes by Dietary Phytochemicals in Vascular Diseases

Vascular diseases are major causes of death worldwide, causing pathologies including diabetes, atherosclerosis, and chronic obstructive pulmonary disease (COPD). Exposure of the vascular system to a variety of stressors and inducers has been implicated in the development of various human diseases, including chronic inflammatory diseases. In the vascular wall, antioxidant enzymes form the first line of defense against oxidative stress. Recently, extensive research into the beneficial effects of phytochemicals has been conducted; phytochemicals are found in commonly used spices, fruits, and herbs, and are used to prevent various pathologic conditions, including vascular diseases. The present review aims to highlight the effects of dietary phytochemicals role on antioxidant enzymes in vascular diseases.

The multi-faceted role of retinoid X receptor in cardiovascular diseases

Retinoid X receptors (RXRs) are members of ligand-dependent transcription factors whose effects on a diversity of cellular processes, including cellular proliferation, the immune response, and lipid and glucose metabolism. Knock out of RXRα causes a hypoplasia of the myocardium which is lethal during fetal life. In addition, the heart maintains a well-orchestrated balances in utilizing fatty acids (FAs) and other substrates to meet the high energy requirements. As the master transcriptional regulators of lipid metabolism, RXRs become particularly important for the energy needs of the heart. Accumulating evidence suggested that RXRs may exert direct beneficial effects in the heart both through heterodimerization with other nuclear receptors (NRs) and homodimerization, thus standing as suitable targets for treating in cardiovascular diseases. Although compounds that target RXRs are promising drugs, their use is limited by toxicity. A better understanding of the structural biology of RXRs in cardiovascular disease should enable the rational design of more selective nuclear receptor modulators to overcome these problems. Here, this review summarizes a brief overview of RXRs structure and versatility of RXR action in the control of cardiovascular diseases. And we also discussed the therapeutic potential of RXR ligand.

Morpho-functional remodelling of the adult zebrafish (Danio rerio) heart in response to waterborne angiotensin II exposure

Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System, is a pluripotent humoral agent whose biological actions include short-term modulations and long-term adaptations. In fish, short-term cardio-tropic effects of AngII are documented, but information on the role of AngII in long-term cardiac remodelling is not fully understood. Here, we describe a direct approach to disclose long-term morpho-functional effects of AngII on the zebrafish heart. Adult fish exposed to waterborne teleost analogue AngII for 8 weeks showed enhanced heart weight and cardio-somatic index, coupled to myocardial structural changes (i.e. augmented compacta thickness and fibrosis), and increased heart rate. These findings were paralleled by an up-regulation of type-1 and type-2 AngII receptors expression, and by changes in the expression of GATA binding protein 4, nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 and superoxide dismutase 1 soluble mRNAs, as well as of cytochrome b-245 beta polypeptide protein, indicative of cardiac remodelling. Our results suggest that waterborne AngII can sustain and robustly affect the cardiac morpho-functional remodelling of adult zebrafish.

Echinacoside reverses myocardial remodeling and improves heart function via regulating SIRT1/FOXO3a/MnSOD axis in HF rats induced by isoproterenol

Myocardial remodelling is important pathological basis of HF, mitochondrial oxidative stress is a promoter to myocardial hypertrophy, fibrosis and apoptosis. ECH is the major active component of a traditional Chinese medicine Cistanches Herba, plenty of studies indicate it possesses a strong antioxidant capacity in nerve cells and tumour, it inhibits mitochondrial oxidative stress, protects mitochondrial function, but the specific mechanism is unclear. SIRT1/FOXO3a/MnSOD is an important antioxidant axis, study finds that ECH binds covalently to SIRT1 as a ligand and up-regulates the expression of SIRT1 in brain cells. We hypothesizes that ECH may reverse myocardial remodelling and improve heart function of HF via regulating SIRT1/FOXO3a/MnSOD signalling axis and inhibit mitochondrial oxidative stress in cardiomyocytes. Here, we firstly induce cellular model of oxidative stress by ISO with AC-16 cells and pre-treat with ECH, the level of mitochondrial ROS, mtDNA oxidative injury, MMP, carbonylated protein, lipid peroxidation, intracellular ROS and apoptosis are detected, confirm the effect of ECH in mitochondrial oxidative stress and function in vitro. Then, we establish a HF rat model induced by ISO and pre-treat with ECH. Indexes of heart function, myocardial remodelling, mitochondrial oxidative stress and function, expression of SIRT1/FOXO3a/MnSOD signalling axis are measured, the data indicate that ECH improves heart function, inhibits myocardial hypertrophy, fibrosis and apoptosis, increases the expression of SIRT1/FOXO3a/MnSOD signalling axis, reduces the mitochondrial oxidative damages, protects mitochondrial function. We conclude that ECH reverses myocardial remodelling and improves cardiac function via up-regulating SIRT1/FOXO3a/MnSOD axis and inhibiting mitochondrial oxidative stress in HF rats.

Fisetin protects against streptozotocin-induced diabetic cardiomyopathy in rats by suppressing fatty acid oxidation and inhibiting protein kinase R

This study examined if the Fisetin against streptozotocin-induced diabetic cardiomyopathy (DC) in rats involves regulating cardiac metabolism and suppressing protein kinase R (PKR). Male rats were divided (12/groups) as control (non-diabetic), control + Fisetin, T1DM, and T1DM + Fisetin. Fisetin was administered orally at a final dose of 2.5 mg/kg for 12 weeks. In T1DM1-induced rats, Fisetin prevented heart and final body weights loss, lowered circulatory levels troponin I and creatinine kinase-MB (CK-MB), increased fasting insulin levels, and improved ventricular systolic and diastolic functions. It also preserved the structure of the cardiomyocytes and reduced oxidative stress, fibrosis, protein levels of transforming growth factor-β1 (TGF-β1), collagenase 1A, caspase-3, and the activation of JNK, p53, and p38 MAPK. In the control and diabetic rats, Fisetin attenuated fasting hyperglycaemia, the increases in glucose levels after the oral and insulin tolerance tests, and HOMA-IR. It also increased cardiac glucose oxidation by increasing the activity of private dehydrogenase (PDH), phosphofructokinase (PFK), protein levels of PPAR-α and suppressed cardiac inflammation by inhibiting NF-κB. These effects were associated with a reduction in the activity of PKR and subsequent increase in the activity of eeukaryotic initiation factor 2 (eIF2) with a parallel increase in protein levels of p67, a cellular inhibitor of PKR. In cultured cardiomyocytes, Fisetin, prevented high glucose (HG)-induced activation of PKR and reduction in p67, in a dose-dependent manner. However, the effect of Fisetin on PKR was diminished in LG and HG-treated cardiomyocytes with p67-siRNA. In conclusion, Fisetin protects against DC in rats by improving cardiac glucose metabolism and suppressing PKR.

Hispidulin Attenuates Cardiac Hypertrophy by Improving Mitochondrial Dysfunction

Cardiac hypertrophy is a pathophysiological response to harmful stimuli. The continued presence of cardiac hypertrophy will ultimately develop into heart failure. The mitochondrion is the primary organelle of energy production, and its dysfunction plays a crucial role in the progressive development of heart failure from cardiac hypertrophy. Hispidulin, a natural flavonoid, has been substantiated to improve energy metabolism and inhibit oxidative stress. However, how hispidulin regulates cardiac hypertrophy and its underlying mechanism remains unknown. We found that hispidulin significantly inhibited pressure overload-induced cardiac hypertrophy and improved cardiac function in vivo and blocked phenylephrine (PE)-induced cardiomyocyte hypertrophy in vitro. We further proved that hispidulin remarkably improved mitochondrial function, manifested by increased electron transport chain (ETC) subunits expression, elevated ATP production, increased oxygen consumption rates (OCR), normalized mitochondrial morphology, and reduced oxidative stress. Furthermore, we discovered that Sirt1, a well-recognized regulator of mitochondrial function, might be a target of hispidulin, as evidenced by its upregulation after hispidulin treatment. Cotreatment with EX527 (a Sirt1-specific inhibitor) and hispidulin nearly completely abolished the antihypertrophic and protective effects of hispidulin on mitochondrial function, providing further evidence that Sirt1 could be the pivotal downstream effector of hispidulin in regulating cardiac hypertrophy.

Current state and future perspective of cardiovascular medicines derived from natural products

The contribution of natural products (NPs) to cardiovascular medicine has been extensively documented, and many have been used for centuries. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Over the past 40 years, approximately 50% of newly developed cardiovascular drugs were based on NPs, suggesting that NPs provide essential skeletal structures for the discovery of novel medicines. After a period of lower productivity since the 1990s, NPs have recently regained scientific and commercial attention, leveraging the wealth of knowledge provided by multi-omics, combinatorial biosynthesis, synthetic biology, integrative pharmacology, analytical and computational technologies. In addition, as a crucial part of complementary and alternative medicine, Traditional Chinese Medicine has increasingly drawn attention as an important source of NPs for cardiovascular drug discovery. Given their structural diversity and biological activity NPs are one of the most valuable sources of drugs and drug leads. In this review, we briefly described the characteristics and classification of NPs in CVDs. Then, we provide an up to date summary on the therapeutic potential and the underlying mechanisms of action of NPs in CVDs, and the current view and future prospect of developing safer and more effective cardiovascular drugs based on NPs.

Peroxiredoxin-1 ameliorates pressure overload-induced cardiac hypertrophy and fibrosis

BACKGROUND

Previous studies have demonstrated that Peroxiredoxin 1 (Prdx1) is a modulator of physiological and pathophysiological cardiovascular events. However, the roles of Prdx1 in cardiac hypertrophy and heart failure (HF) have barely been explored. Thus, this study aimed to investigate whether Prdx1 participates in cardiac hypertrophy and to elucidate the possible associated mechanisms.

METHODS

Mice were subjected to transverse aortic constriction (TAC) for four weeks to induce pathological cardiac hypertrophy. Cardiomyocyte-specific Prdx1 overexpression in mice was achieved using an adeno-associated virus system. Morphological examination; echocardiography; and hemodynamic, biochemical and histological analyses were used to evaluate the roles of Prdx1 in pressure overload-induced cardiac hypertrophy and HF.

RESULTS

First, the results showed that Prdx1 expression was noticeably upregulated in hypertrophic mouse hearts and cardiomyocytes with phenylephrine (PE)-induced hypertrophy in vitro. Prdx1 overexpression exerted protective effects against cardiac hypertrophy and fibrosis and ameliorated cardiac dysfunction in mice subjected to pressure overload. In addition, Prdx1 overexpression decreased pressure overload-induced cardiac inflammation and oxidative stress. Further studies demonstrated that Prdx1 overexpression increased the levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant protein, heme oxygenase-1 (HO-1), in mice. Moreover, Nrf2 knockdown offset the antihypertrophic and anti-oxidative stress effects of Prdx1 overexpression.

CONCLUSIONS

Prdx1 protects against pressure overload-induced cardiac hypertrophy and HF by activating Nrf2/HO-1 signaling. These data indicate that targeting Prdx1 may be an attractive pharmacotherapeutic strategy for the treatment of cardiac hypertrophy and HF.

Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease

Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.

Exploring Molecular Mechanism of Huangqi in Treating Heart Failure Using Network Pharmacology

Heart failure (HF), a clinical syndrome with a high incidence due to various reasons, is the advanced stage of most cardiovascular diseases. Huangqi is an effective treatment for cardiovascular disease, which has multitarget, multipathway functions. Therefore, we used network pharmacology to explore the molecular mechanism of Huangqi in treating HF. In this study, 21 compounds of Huangqi, which involved 407 targets, were obtained and reconfirmed using TCMSP and PubChem databases. Moreover, we used Cytoscape 3.7.1 to construct compound-target network and screened the top 10 compounds. 378 targets related to HF were obtained from CTD and GeneCards databases and HF-target network was constructed by Cytoscape 3.7.1. The 46 overlapping targets of HF and Huangqi were gotten by Draw Venn Diagram. STRING database was used to set up a protein-protein interaction network, and MCODE module and the top 5 targets with the highest degree for overlapping targets were obtained. GO analysis performed by Metascape indicated that the overlapping targets were mainly enriched in blood vessel development, reactive oxygen species metabolic process, response to wounding, blood circulation, and so on. KEGG analysis analyzed by ClueGO revealed that overlapping targets were mainly enriched in AGE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, HIF-1 signaling pathway, c-type lectin receptor signaling pathway, relaxin signaling pathway, and so on. Finally, molecular docking showed that top 10 compounds of Huangqi also had good binding activities to important targets compared with digoxin, which was carried out in CB-Dock molecular docking server. In conclusion, Huangqi has potential effect on regulating overlapping targets and GE-RAGE signaling pathway in diabetic complications, IL-17 signaling pathway, HIF-1 signaling pathway, and so on to be a latent multitarget, multipathway treatment for HF.

Therapeutic potential of polyphenols in cardiovascular diseases: Regulation of mTOR signaling pathway

Cardiovascular diseases comprise of non-communicable disorders that involve the heart and/or blood vessels and have become the leading cause of death worldwide with increased prevalence by age. mTOR is a serine/threonine-specific protein kinase which plays a central role in many physiological processes including cardiovascular diseases, and also integrates various proliferative signals, nutrient and energy abundance and stressful situations. mTOR also acts as central regulator during chronic stress, mitochondrial dysfunction and deregulated autophagy which are associated with senescence. Under oxidative stress, mTOR has been reported to exert protective effects regulating apoptosis and autophagy processes and favoring tissue repair. On the other hand, inhibition of mTOR has been suggested to have beneficial effects against atherosclerosis, cardiac hypertrophy and heart failure, and also in extending the lifespan. In this aspect, the use of drugs or natural compounds, which can target mTOR is an interesting approach in order to reduce the number of deaths caused by cardiovascular disease. In the present review, we intend to shed light on the possible effects and molecular mechanism of natural agents like polyphenols via regulating mTOR.

Oral flavonoid fisetin treatment protects against prolonged high-fat-diet-induced cardiac dysfunction by regulation of multicombined signaling

Excess high-fat diet (HFD) intake predisposes the occurrence of obesity-associated heart injury, but the mechanism is elusive. Fisetin (FIS), as a natural flavonoid, has potential activities to alleviate obesity-induced metabolic syndrome. However, the underlying molecular mechanisms of FIS against HFD-induced cardiac injury remain unclear. The present study was to explore the protective effects of FIS on cardiac dysfunction in HFD-fed mice. We found that FIS alleviated HFD-triggered metabolic disorder by reducing body weight, fasting blood glucose and insulin levels, and insulin resistance. Moreover, FIS supplements significantly alleviated dyslipidemia in both mouse hearts and cardiomyocytes stimulated by metabolic stress. FIS treatment abolished HFD-induced inflammatory response in heart tissues through suppressing TNF receptor-1/TNF receptor-associated factor-2 (Tnfr-1/Traf-2) signaling. Furthermore, FIS induced a strong reduction in the expression of fibrosis-related genes, contributing to the inhibition of fibrosis by inactivating transforming growth factor (Tgf)-β1/Smads/Erk1/2 signaling. Collectively, these results demonstrated that FIS could be a promising therapeutic strategy for the treatment of obesity-associated cardiac injury.

NADPH Oxidase Hyperactivity Contributes to Cardiac Dysfunction and Apoptosis in Rats with Severe Experimental Pancreatitis through ROS-Mediated MAPK Signaling Pathway

NADPH oxidase (Nox) is considered a major source of reactive oxygen species (ROS) in the heart in normal and pathological conditions. However, the role of Nox in severe acute pancreatitis- (SAP-) associated cardiac injury remains unclear. Therefore, we aim to investigate the contribution of Nox to SAP-associated cardiac injury and to explore the underlying molecular mechanisms. Apocynin, a Nox inhibitor, was given at 20 mg/kg for 30 min before SAP induction by a retrograde pancreatic duct injection of 5% sodium taurocholate. Histopathological staining, Nox activity and protein expression, oxidative stress markers, apoptosis and associated proteins, cardiac-related enzyme indexes, and cardiac function were assessed in the myocardium in SAP rats. The redox-sensitive MAPK signaling molecules were also examined by western blotting. SAP rats exhibited significant cardiac impairment along with increased Nox activity and protein expression, ROS production, cell apoptosis, and proapoptotic Bax and cleaved caspase-3 protein levels. Notably, Nox inhibition with apocynin prevented SAP-associated cardiac injury evidenced by a decreased histopathologic score, cardiac-related enzymes, and cardiac function through the reduction of ROS production and cell apoptosis. This protective role was further confirmed by a simulation experiment in vitro. Moreover, we found that SAP-induced activation in MAPK signaling molecules in cardiomyocytes was significantly attenuated by Nox inhibition. Our data provide the first evidence that Nox hyperactivation acts as the main source of ROS production in the myocardium, increases oxidative stress, and promotes cell apoptosis via activating the MAPK pathway, which ultimately results in cardiac injury in SAP.

Fisetin ameliorates oxidative stress, inflammation and apoptosis in diabetic cardiomyopathy

AIMS

Hyperglycemia-mediated oxidative damage has been described as a major mechanism leading to pathologic changes associated with diabetic cardiomyopathy (DCM). Fisetin is a bioactive flavonol molecule found in many plants and possesses various biological activities. The present study investigated the protective effect of fisetin on diabetes-induced cardiac injury.

METHODS

Diabetes was induced by streptozotocin (STZ) and both diabetic and control rats were treated with 2.5 mg/kg fisetin for six weeks.

KEY FINDINGS

Diabetic rats exhibited hyperglycemia, and increased glycosylated hemoglobin and serum lipids accompanied with significant hypoinsulinism. In addition, diabetic rats showed several histological alterations in the myocardium, and significantly increased serum troponin I, creatine kinase-MB and lactate dehydrogenase. Oxidative stress, inflammation and apoptosis markers were increased, whereas antioxidant defenses were significantly reduced in the diabetic heart. Treatment with fisetin alleviated hyperglycemia, hyperlipidemia and heart function markers, and minimized histological alterations in the myocardium. Fisetin suppressed oxidative stress, prevented inflammation and apoptosis, and boosted antioxidant defenses in the heart of diabetic rats.

SIGNIFICANCE

Fisetin attenuated the development of DCM via amelioration of hyperglycemia/hyperlipidemia-mediated oxidative stress, inflammation and apoptosis. Therefore, it might be worth considering the therapeutic potential of fisetin for human DCM.

Inhibitory Effects of Roseoside and Icariside E4 Isolated from a Natural Product Mixture (No-ap) on the Expression of Angiotensin II Receptor 1 and Oxidative Stress in Angiotensin II-Stimulated H9C2 Cells

Hypertension is a major risk factor for the development of cardiovascular diseases. This study aimed to elucidate whether the natural product mixture No-ap (NA) containing Pine densiflora, Annona muricate, and Monordica charantia, or its single components have inhibitory effects on hypertension-related molecules in Angiotensin II (Ang II)-stimulated H9C2 cells. Individual functional components were isolated and purified from NA using various columns and solvents, and then their structures were analyzed using ESI–MS, ¹H-NMR, and ¹³H-NMR spectra. H9C2 cells were stimulated with 300 nM Ang II for 7 h. NA, telmisartan, ginsenoside, roseoside (Roseo), icariside E4 (IE4), or a combination of two components (Roseo and IE4) were administered to the cells 1 h before Ang II stimulation. The expression and activity of hypertension-related molecules or oxidative molecules were determined using RT-PCR, western blot, and ELISA. Ang II stimulation increased the expression of Ang II receptor 1 (AT1), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), tumor growth factor-β (TGF-β) mRNA, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and the levels of hydrogen peroxide (H₂O₂) and superoxide anion (•O₂⁻) and reduced anti-oxidant enzyme activity. NA significantly improved the expression or activities of all hypertension-related molecules altered in Ang II-stimulated cells. Roseo or IE4 pretreatment either decreased or increased the expression or activities of all hypertension-related molecules similar to NA, but to a lesser extent. The pretreatment with a combination of Roseo and IE4 (1:1) either decreased or increased the expression of all hypertension-related molecules, compared to each single component, revealing a synergistic action of the two compounds. Thus, the combination of single components could exert promising anti-hypertensive effects similar to NA, which should be examined in future animal and clinical studies.