The Citrus Flavonoid Naringenin Protects the Myocardium from Ageing-Dependent Dysfunction: Potential Role of SIRT1

The Citrus flavanone naringenin prolongs the lifespan in C. elegans and slows signs of brain aging in mice

Aging is one of the main risk factors for neurodegenerative disorders, which represent a global burden on healthcare systems. Therefore, identifying new strategies to slow the progression of brain aging is a compelling challenge. In this article, we first assessed the potential anti-aging effects of the Citrus flavanone naringenin (NAR), an activator of the enzyme sirtuin-1 (SIRT1), in a 3R-compliant and short-lived aging model (i.e., the nematode C. elegans). Then, we investigated the preventive effects of a 6-month treatment with NAR (100 mg/kg, orally) against brain aging and studied its mechanism of action in middle-aged mice. We demonstrated that NAR (100 μM) extends lifespan and improves healthspan in C. elegans. In the brain of middle-aged mice, NAR promotes the activity of metabolic enzymes (citrate synthase, cytochrome C oxidase) and increases the expression of the SIRT1 enzyme. Consistently, NAR up-regulates the expression of downstream antioxidant (Foxo3, Nrf2, Ho-1), anti-senescence (p16), and anti-inflammatory (Il-6, Il-18) markers. Our findings support NAR supplementation to slow the signs of brain aging.

Intermittent Fasting: Myths, Fakes and Truth on This Dietary Regimen Approach

Intermittent fasting (IF) has been indicated as a valuable alternative to the classical caloric restriction dietary regimen for lowering body weight and preventing obesity-related complications, such as metabolic syndrome and type II diabetes. However, is it effective? In this review article, we analyzed over 50 clinical studies in which IF, conducted by alternate day fasting (ADF) or time-restricted feeding (TRF), was compared with the caloric restriction approach. We evaluated the different roles of IF in treating and preventing human disorders such as metabolic syndrome, type II diabetes, and some types of cancer, as well as the usefulness of IF in reducing body weight and cardiovascular risk factors such as hypertension. Furthermore, we explored the cellular pathways targeted by IF to exert their beneficial effects by activating effector proteins that modulate cell functions and resistance to oxidative stress. In contrast, we investigated concerns regarding human health related to the adoption of IF dietary regimens, highlighting the profound debate surrounding weight loss regimens. We examined and compared several clinical trials to formulate an updated concept regarding IF and its therapeutic potential.

Research status of pathogenesis of anxiety or depression after percutaneous coronary intervention and Traditional Chinese Medicine intervention

ETHNIC PHARMACOLOGICAL RELEVANCE

Anxiety or depression after percutaneous coronary intervention (PCI) is a common clinical disease. Currently, conventional pharmacotherapy primarily involves the administration of anxiolytic or antidepressant medications in conjunction with anticoagulants, antiplatelet agents, and other cardiovascular drugs. However, challenges such as drug dependence, adverse reactions and related concerns persist in the treatment of this disease. Numerous pertinent studies have demonstrated that Traditional Chinese Medicine (TCM) exhibits significant therapeutic efficacy and distinctive advantages in managing post-PCI anxiety or depression.

AIM OF THIS REVIEW

This review attempted to summarize the characteristics of TCM for treating anxiety or depression after PCI, including single Chinese herbs, Chinese medicine monomers, compound TCM prescriptions, TCM patented drugs, and other TCM-related treatment methods, focusing on the analysis of the relevant mechanism of TCM treatment of this disease.

METHODS

By searching the literature on treating anxiety or depression after PCI with TCM in PubMed, Web of Science, CNKI, and other relevant databases, this review focuses on the latest research progress of TCM treatment of this disease.

RESULTS

In the treatment of anxiety or depression after PCI, TCM exerts significant pharmacological effects such as anti-inflammatory, antioxidant, anti-anxiety or anti-depression, cardiovascular and cerebrovascular protection, and neuroprotection, mainly by regulating the levels of related inflammatory factors, oxidative stress markers, neurotransmitter levels, and related signaling pathways. TCM has a good clinical effect in treating anxiety or depression after PCI with individualized treatment.

CONCLUSIONS

TCM has terrific potential and good prospects in the treatment of anxiety or depression after PCI. The main direction of future exploration is the study of the mechanism related to Chinese medicine monomers and the large sample clinical study related to compound TCM prescriptions.

Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.

Sirtuins as Players in the Signal Transduction of Citrus Flavonoids

Sirtuins (SIRTs) belong to the family of nicotine adenine dinucleotide (NAD+)-dependent class III histone deacetylases, which come into play in the regulation of epigenetic processes through the deacetylation of histones and other substrates. The human genome encodes for seven homologs (SIRT1-7), which are localized into the nucleus, cytoplasm, and mitochondria, with different enzymatic activities and regulatory mechanisms. Indeed, SIRTs are involved in different physio-pathological processes responsible for the onset of several human illnesses, such as cardiovascular and neurodegenerative diseases, obesity and diabetes, age-related disorders, and cancer. Nowadays, it is well-known that Citrus fruits, typical of the Mediterranean diet, are an important source of bioactive compounds, such as polyphenols. Among these, flavonoids are recognized as potential agents endowed with a wide range of beneficial properties, including antioxidant, anti-inflammatory, hypolipidemic, and antitumoral ones. On these bases, we offer a comprehensive overview on biological effects exerted by Citrus flavonoids via targeting SIRTs, which acted as modulator of several signaling pathways. According to the reported studies, Citrus flavonoids appear to be promising SIRT modulators in many different pathologies, a role which might be potentially evaluated in future therapies, along with encouraging the study of those SIRT members which still lack proper evidence on their support.

The potential of herbal drugs to treat heart failure: The roles of Sirt1/AMPK

Heart failure (HF) is a highly morbid syndrome that seriously affects the physical and mental health of patients and generates an enormous socio-economic burden. In addition to cardiac myocyte oxidative stress and apoptosis, which are considered mechanisms for the development of HF, alterations in cardiac energy metabolism and pathological autophagy also contribute to cardiac abnormalities and ultimately HF. Silent information regulator 1 (Sirt1) and adenosine monophosphate-activated protein kinase (AMPK) are nicotinamide adenine dinucleotide (NAD+)-dependent deacetylases and phosphorylated kinases, respectively. They play similar roles in regulating some pathological processes of the heart through regulating targets such as peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), protein 38 mitogen-activated protein kinase (p38 MAPK), peroxisome proliferator-activated receptors (PPARs), and mammalian target of rapamycin (mTOR). We summarized the synergistic effects of Sirt1 and AMPK in the heart, and listed the traditional Chinese medicine (TCM) that exhibit cardioprotective properties by modulating the Sirt1/AMPK pathway, to provide a basis for the development of Sirt1/AMPK activators or inhibitors for the treatment of HF and other cardiovascular diseases (CVDs).

Sirtuin 1-activating derivatives belonging to the anilinopyridine class displaying in vivo cardioprotective activities

Sirtuin 1 (SIRT1) is an enzyme that relies on NAD+ cofactor and functions as a deacetylase. It has been associated with various biological and pathological processes, including cancer, diabetes, and cardiovascular diseases. Recent studies have shown that compounds that activate SIRT1 exhibit protective effects on the heart. Consequently, targeting SIRT1 has emerged as a viable approach to treat cardiovascular diseases, leading to the identification of several SIRT1 activators derived from natural or synthetic sources. In this study, we developed anilinopyridine-based SIRT1 activators that displayed significantly greater potency in activating SIRT1 compared to the reference compound resveratrol, as demonstrated in enzymatic assays. In particular, compounds 8 and 10, representative 6-aryl-2-anilinopyridine derivatives from this series, were further investigated pharmacologically and found to reduce myocardial damage caused by occlusion and subsequent reperfusion in vivo, confirming their cardioprotective properties. Notably, the cardioprotective effects of 8 and 10 were significantly superior to that of resveratrol. Significantly, compound 10 emerged as the most potent among the tested compounds, demonstrating the ability to substantially decrease the size of the ischemic area at a dosage one hundred times lower (0.1 mg kg-1) than that of resveratrol/compound 1. These promising findings open avenues for expanding and optimizing this chemical class of potent SIRT1 activators as potential agents for cardioprotection.

Understanding cellular senescence: pathways involved, therapeutics and longevity aiding

A normal somatic cell undergoes cycles of finite cellular divisions. The presence of surveillance checkpoints arrests cell division in response to stress inducers: oxidative stress from excess free radicals, oncogene-induced abnormalities, genotoxic stress, and telomere attrition. When facing such stress when undergoing these damages, there is a brief pause in the cell cycle to enable repair mechanisms. Also, the nature of stress determines whether the cell goes for repair or permanent arrest. As the cells experience transient or permanent stress, they subsequently choose the quiescence or senescence stage, respectively. Quiescence is an essential stage that allows the arrested/damaged cells to go through appropriate repair mechanisms and then revert to the mainstream cell cycle. However, senescent cells are irreversible and accumulate with age, resulting in inflammation and various age-related disorders. In this review, we focus on senescence-associated pathways and therapeutics understanding cellular senescence as a cascade that leads to aging, while discussing the recent details on the molecular pathways involved in regulating senescence and the benefits of therapeutic strategies against accumulated senescent cells and their secretions.

Flavonoids: Overview of Biosynthesis, Biological Activity, and Current Extraction Techniques

Recently, increased attention has been paid to natural sources as raw materials for the development of new added-value products. Flavonoids are a large family of polyphenols which include several classes based on their basic structure: flavanones, flavones, isoflavones, flavonols, flavanols, and anthocyanins. They have a multitude of biological properties, such as anti-inflammatory, antioxidant, antiviral, antimicrobial, anticancer, cardioprotective, and neuroprotective effects. Current trends of research and development on flavonoids relate to identification, extraction, isolation, physico-chemical characterization, and their applications to health benefits. This review presents an up-to-date survey of the most recent developments in the natural flavonoid classes, the biological activity of representative flavonoids, current extraction techniques, and perspectives.

A Review of Classification, Biosynthesis, Biological Activities and Potential Applications of Flavonoids

Flavonoids represent the main class of plant secondary metabolites and occur in the tissues and organs of various plant species. In plants, flavonoids are involved in many biological processes and in response to various environmental stresses. The consumption of flavonoids has been known to reduce the risk of many chronic diseases due to their antioxidant and free radical scavenging properties. In the present review, we summarize the classification, distribution, biosynthesis pathways, and regulatory mechanisms of flavonoids. Moreover, we investigated their biological activities and discuss their applications in food processing and cosmetics, as well as their pharmaceutical and medical uses. Current trends in flavonoid research are also briefly described, including the mining of new functional genes and metabolites through omics research and the engineering of flavonoids using nanotechnology. This review provides a reference for basic and applied research on flavonoid compounds.

The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases

The endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.

Influence of Polyphenols on Adipose Tissue: Sirtuins as Pivotal Players in the Browning Process

Adipose tissue (AT) can be classified into two different types: (i) white adipose tissue (WAT), which represents the largest amount of total AT, and has the main function of storing fatty acids for energy needs and (ii) brown adipose tissue (BAT), rich in mitochondria and specialized in thermogenesis. Many exogenous stimuli, e.g., cold, exercise or pharmacological/nutraceutical tools, promote the phenotypic change of WAT to a beige phenotype (BeAT), with intermediate characteristics between BAT and WAT; this process is called "browning". The modulation of AT differentiation towards WAT or BAT, and the phenotypic switch to BeAT, seem to be crucial steps to limit weight gain. Polyphenols are emerging as compounds able to induce browning and thermogenesis processes, potentially via activation of sirtuins. SIRT1 (the most investigated sirtuin) activates a factor involved in mitochondrial biogenesis, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), which, through peroxisome proliferator-activated receptor γ (PPAR-γ) modulation, induces typical genes of BAT and inhibits genes of WAT during the transdifferentiation process in white adipocytes. This review article aims to summarize the current evidence, from pre-clinical studies to clinical trials, on the ability of polyphenols to promote the browning process, with a specific focus on the potential role of sirtuins in the pharmacological/nutraceutical effects of natural compounds.

Possible Side Effects of Polyphenols and Their Interactions with Medicines

Polyphenols are an important component of plant-derived food with a wide spectrum of beneficial effects on human health. For many years, they have aroused great interest, especially due to their antioxidant properties, which are used in the prevention and treatment of many diseases. Unfortunately, as with any chemical substance, depending on the conditions, dose, and interactions with the environment, it is possible for polyphenols to also exert harmful effects. This review presents a comprehensive current state of the knowledge on the negative impact of polyphenols on human health, describing the possible side effects of polyphenol intake, especially in the form of supplements. The review begins with a brief overview of the physiological role of polyphenols and their potential use in disease prevention, followed by the harmful effects of polyphenols which are exerted in particular situations. The individual chapters discuss the consequences of polyphenols’ ability to block iron uptake, which in some subpopulations can be harmful, as well as the possible inhibition of digestive enzymes, inhibition of intestinal microbiota, interactions of polyphenolic compounds with drugs, and impact on hormonal balance. Finally, the prooxidative activity of polyphenols as well as their mutagenic, carcinogenic, and genotoxic effects are presented. According to the authors, there is a need to raise public awareness about the possible side effects of polyphenols supplementation, especially in the case of vulnerable subpopulations.

Naringenin attenuates cerebral ischemia/reperfusion injury by inhibiting oxidative stress and inflammatory response via the activation of SIRT1/FOXO1 signaling pathway in vitro

PURPOSE

To explore the protection of naringenin against oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cell injury, a cell model of cerebral ischemia/reperfusion (I/R) injury in vitro, focusing on SIRT1/FOXO1 signaling pathway.

METHODS

Cytotoxicity, apoptosis, reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, 4-hydroxynonenoic acid (4-HNE) level, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured by commercial kits. Inflammatory cytokines levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein expressions were monitored by Western blot analysis.

RESULTS

Naringenin significantly ameliorated OGD/R-induced cytotoxicity and apoptosis in HT22 cells. Meanwhile, naringenin promoted SIRT1 and FOXO1 protein expressions in OGD/R-subjected HT22 cells. In addition, naringenin attenuated OGD/R-induced cytotoxicity, apoptosis, oxidative stress (the increased ROS, MDA and 4-HNE levels, and the decreased SOD, GSH-Px and CAT activities) and inflammatory response (the increased tumor necrosis factor-α, interleukin [IL]-1β, and IL-6 levels and the decreased IL-10 level), which were blocked by the inhibition of the SIRT1/FOXO1 signaling pathway induced by SIRT1-siRNA transfection.

CONCLUSIONS

Naringenin protected HT22 cells against OGD/R injury depending on its antioxidant and anti-inflammatory activities via promoting the SIRT1/FOXO1 signaling pathway.

Resveratrol-like Compounds as SIRT1 Activators

The sirtuin 1 (SIRT1) activator resveratrol has emerged as a promising candidate for the prevention of vascular oxidative stress, which is a trigger for endothelial dysfunction. However, its clinical use is limited by low oral bioavailability. In this work, we have applied a previously developed computational protocol to identify the most promising derivatives from our in-house chemical library of resveratrol derivatives. The most promising compounds in terms of SIRT1 activation and oral bioavailability, predicted in silico, were evaluated for their ability to activate the isolated SIRT1 enzyme. Then, we assessed the antioxidant effects of the most effective derivative, compound 3d, in human umbilical vein endothelial cells (HUVECs) injured with H₂O₂ 100 µM. The SIRT1 activator 3d significantly preserved cell viability and prevented an intracellular reactive oxygen species increase in HUVECs exposed to the oxidative stimulus. Such effects were partially reduced in the presence of a sirtuin inhibitor, sirtinol, confirming the potential role of sirtuins in the activity of resveratrol and its derivatives. Although 3d appeared less effective than resveratrol in activating the isolated enzyme, the effects exhibited by both compounds in HUVECs were almost superimposable, suggesting a higher ability of 3d to cross cell membranes and activate the intracellular target SIRT1.

Network pharmacology-based and experimental identification of the effects of Renshen Yangrong decoction on myocardial infarction

Objective: Myocardial infarction (MI) is one of the leading causes of death worldwide. Currently, the drugs used to treat MI have various side effects. Emerging evidence supports the protective effects of Renshen Yangrong Decoction (RSYRD) in cardiovascular diseases (CVDs) treatments, with few side effect reports. However, the role of RSYRD in MI remains unclear. In this study, network pharmacological analysis was combined with experiments in vivo and in vitro to validate the effects of RSYRD in the treatment during the early stage of MI.

Methods: Firstly, network pharmacology analysis was performed to search for the potential targets and signaling pathways of RSYRD in the early stage of MI. Then, the protein-protein interaction (PPI) network was constructed to identify the core genes of RSYRD that may play a key role in MI. At last, the treatment effectiveness of RSYRD on MI was verified via experiments in vitro and in vivo.

Results: RSYRD contained fifty-six bioactive components. Eighty-eight intersections between RSYRD and MI targets and thirteen core genes were screened. KEGG and GO functional enrichment analyses predicted that RSYRD might play a therapeutic role in MI through oxidative stress, apoptosis, and immune-inflammatory signaling pathways. In vivo and in vitro experiment results revealed that significant apoptosis occurred in myocardial tissue in the early stage of MI. Moreover, the levels of reactive oxide species (ROS), TNF-α, and IL-6 increased markedly. After RSYRD administration, they significantly decreased. At the mechanistic level, RSYRD could reduce ROS production to alleviate cell apoptosis.

Conclusion: RSYRD could reduce neonatal mouse cardiomyocytes (NMCMs) apoptosis by lowering ROS production induced by hypoxia and improve the cardiac function of mice 3 days post-MI. RSYRD could also reduce the levels of TNF-α and IL-6 in the serum of mice.

Sirtuin 1-Activating Compounds: Discovery of a Class of Thiazole-Based Derivatives

Sirtuin 1 (SIRT1) is a NAD⁺-dependent deacetylase implicated in various biological and pathological processes, including cancer, diabetes, and cardiovascular diseases. In recent years, SIRT1-activating compounds have been demonstrated to exert cardioprotective effects. Therefore, this enzyme has become a feasible target to treat cardiovascular diseases, and many SIRT1 activators, of a natural or synthetic origin, have been identified. In the present work, we developed thiazole-based SIRT1 activators, which showed remarkably higher SIRT1 activation potencies compared with those of the reference compound resveratrol when tested in enzymatic assays. Thiazole 8, a representative compound of this series, was also subjected to further pharmacological investigations, where it was proven to reduce myocardial damage induced by an in vivo occlusion/reperfusion event, thus confirming its cardioprotective properties. In addition, the cardioprotective effect of compound 8 was significantly higher than that of resveratrol. Molecular modeling studies suggest the binding mode of these derivatives within SIRT1 in the presence of the p53-AMC peptide. These promising results could pave the way to further expand and optimize this chemical class of new and potent SIRT1 activators as potential cardioprotective agents.

Cardioprotective Effects of Grapefruit IntegroPectin Extracted via Hydrodynamic Cavitation from By-Products of Citrus Fruits Industry: Role of Mitochondrial Potassium Channels

Citrus flavonoids are well-known for their beneficial effects at the cardiovascular and cardio-metabolic level, but often the encouraging in vitro results are not confirmed by in vivo approaches; in addition, the clinical trials are also inconsistent. Their limited bioavailability can be, at least in part, the reason for these discrepancies. Therefore, many efforts have been made towards the improvement of their bioavailability. Hydrodynamic cavitation methods were successfully applied to the extraction of byproducts of the Citrus fruits industry, showing high process yields and affording stable phytocomplexes, known as IntegroPectin, endowed with great amounts of bioactive compounds and high water solubility. The cardioprotective effects of grapefruit IntegroPectin were evaluated by an ex vivo ischemia/reperfusion protocol. Further pharmacological characterization was carried out to assess the involvement of mitochondrial potassium channels. Grapefruit IntegroPectin, where naringin represented 98% of the flavonoids, showed anti-ischemic cardioprotective activity, which was better than pure naringenin (the bioactive aglycone of naringin). On cardiac-isolated mitochondria, this extract confirmed that naringenin/naringin were involved in the activation of mitochondrial potassium channels. The hydrodynamic cavitation-based extraction confirmed a valuable opportunity for the exploitation of Citrus fruits waste, with the end product presenting high levels of Citrus flavonoids and improved bioaccessibility that enhances its nutraceutical and economic value.

Role of resveratrol in inhibiting pathological cardiac remodeling

Cardiovascular disease is a group of diseases with high mortality in clinic, including hypertension, coronary heart disease, cardiomyopathy, heart valve disease, heart failure, to name a few. In the development of cardiovascular diseases, pathological cardiac remodeling is the most common cardiac pathological change, which often becomes a domino to accelerate the deterioration of the disease. Therefore, inhibiting pathological cardiac remodeling may delay the occurrence and development of cardiovascular diseases and provide patients with greater long-term benefits. Resveratrol is a non-flavonoid polyphenol compound. It mainly exists in grapes, berries, peanuts and red wine, and has cardiovascular protective effects, such as anti-oxidation, inhibiting inflammatory reaction, antithrombotic, dilating blood vessels, inhibiting apoptosis and delaying atherosclerosis. At present, the research of resveratrol has made rich progress. This review aims to summarize the possible mechanism of resveratrol against pathological cardiac remodeling, in order to provide some help for the in-depth exploration of the mechanism of inhibiting pathological cardiac remodeling and the development and research of drug targets.

Long-term oral administration of naringenin counteracts aging-related retinal degeneration via regulation of mitochondrial dynamics and autophagy

Aging-related retinal degeneration can manifest as decreased visual function due to damage to retinal structures and dysfunction in retinal homeostasis. Naringenin, a flavonoid, has beneficial effects in preventing cellular aging, preserving the functionality of photoreceptors, and slowing down visual function loss. However, the role and potential mechanism of naringenin in the aging mouse retina require further investigation. In this study, we evaluated the effects of naringenin on the aging eye using electroretinogram (ERG) and hematoxylin and eosin staining and explored its potential mechanism by western blotting. ERG showed that naringenin increased the amplitude of the a- and b-waves of scotopic 3.0, 10.0, and the a-wave amplitude of photopic 3.0 in the aging mouse retina. Furthermore, administration of naringenin prevented aging-induced retinal degeneration in the total retina, ganglion cell, inner plexiform layer, inner nuclear layer, and outer nuclear layer. The expression of mitochondrial fusion protein two was increased, OPA1 protein expression and the ratio of L-OPA1/S-OPA1 were unchanged, and dynamin-related protein one was decreased in the 12-month-old mice treated with naringenin compared with the 12-month-old mice treated with vehicle. Furthermore, the downregulation of age-related alterations in autophagy was significantly rescued in the aging mice by treatment with naringenin. Taken together, these results suggest that the oral administration of naringenin improves visual function, retinal structure, mitochondrial dynamics, and autophagy in the aging mouse retinas. Naringenin may be a potential dietary supplement for the prevention or treatment of aging-related retinal degeneration.

The Role of Antioxidants in the Interplay between Oxidative Stress and Senescence

Cellular senescence is an irreversible state of cell cycle arrest occurring in response to stressful stimuli, such as telomere attrition, DNA damage, reactive oxygen species, and oncogenic proteins. Although beneficial and protective in several physiological processes, an excessive senescent cell burden has been involved in various pathological conditions including aging, tissue dysfunction and chronic diseases. Oxidative stress (OS) can drive senescence due to a loss of balance between pro-oxidant stimuli and antioxidant defences. Therefore, the identification and characterization of antioxidant compounds capable of preventing or counteracting the senescent phenotype is of major interest. However, despite the considerable number of studies, a comprehensive overview of the main antioxidant molecules capable of counteracting OS-induced senescence is still lacking. Here, besides a brief description of the molecular mechanisms implicated in OS-mediated aging, we review and discuss the role of enzymes, mitochondria-targeting compounds, vitamins, carotenoids, organosulfur compounds, nitrogen non-protein molecules, minerals, flavonoids, and non-flavonoids as antioxidant compounds with an anti-aging potential, therefore offering insights into innovative lifespan-extending approaches.

Inhibitors of Mitochondrial Human Carbonic Anhydrases VA and VB as a Therapeutic Strategy against Paclitaxel-Induced Neuropathic Pain in Mice

Neuropathy development is a major dose-limiting side effect of anticancer treatments that significantly reduces patient's quality of life. The inadequate pharmacological approaches for neuropathic pain management warrant the identification of novel therapeutic targets. Mitochondrial dysfunctions that lead to reactive oxygen species (ROS) increase, cytosolic Ca²⁺ imbalance, and lactate acidosis are implicated in neuropathic pain pathogenesis. It has been observed that in these deregulations, a pivotal role is played by the mitochondrial carbonic anhydrases (CA) VA and VB isoforms. Hence, preclinical studies should be conducted to assess the efficacy of two novel selenides bearing benzenesulfonamide moieties, named 5b and 5d, and able to inhibit CA VA and VB against paclitaxel-induced neurotoxicity in mice. Acute treatment with 5b and 5d (30-100 mg/kg, per os - p.o.) determined a dose-dependent and long-lasting anti-hyperalgesic effect in the Cold plate test. Further, repeated daily treatment for 15 days with 100 mg/kg of both compounds (starting the first day of paclitaxel injection) significantly prevented neuropathic pain development without the onset of tolerance to the anti-hyperalgesic effect. In both experiments, acetazolamide (AAZ, 100 mg/kg, p.o.) used as the reference drug was partially active. Moreover, ex vivo analysis demonstrated the efficacy of 5b and 5d repeated treatments in reducing the maladaptive plasticity that occurs to glia cells in the lumbar portion of the spinal cord and in improving mitochondrial functions in the brain and spinal cord that were strongly impaired by paclitaxel-repeated treatment. In this regard, 5b and 5d ameliorated the metabolic activity, as observed by the increase in citrate synthase activity, and preserved an optimal mitochondrial membrane potential (ΔΨ) value, which appeared depolarized in brains from paclitaxel-treated animals. In conclusion, 5b and 5d have therapeutic and protective effects against paclitaxel-induced neuropathy without tolerance development. Moreover, 5b and 5d reduced glial cell activation and mitochondrial dysfunction in the central nervous system, being a promising candidate for the management of neuropathic pain and neurotoxicity evoked by chemotherapeutic drugs.

MiR-34a-5p/Sirt1 axis: A novel pathway for puerarin-mediated hepatoprotection against benzo(a)pyrene

Benzo[a]pyrene (BaP) as a carcinogen induces oxidative stress and inflammation, causing health problems including liver damage. Puerarin (a natural flavonoid) is traditionally used to provide hepatoprotective effects. This research was established to meet the rising demand for effective therapies/treatments against hepatic diseases and investigate the mechanism underlying the protective actions of puerarin against BaP-induced liver damage. In mice, puerarin combated effectively the detrimental changes in liver weight, color and function indices caused by BaP. In HepG2 cells, puerarin alleviated BaP-induced cell death, oxidative stress and inflammation, and such effects were positively correlated with puerarin's concentration (12.5-50 μM). Mechanistic studies revealed that BaP induced low Sirt1 expression and high miR-34a-5p expression, and puerarin treatment alleviated these changes. Oxidative stress and inflammation induced by BaP were almost eliminated when miR-34a-5p was silenced. Inhibiting miR-34a-5p or overexpressing Sirt1 had a similar effect to puerain treatment. Overexpression of miR-34a-5p and inhibition of Sirt1 reduced the protective effect of puerarin. Collectively, miR-34a-5p participates in the regulation of puerarin's protective function against BaP-induced injury through targeting Sirt1. There is a novel pathway for suppressing oxidative stress and inflammation via miR-34a-5p/Sirt1 axis in puerarin-mediated hepatoprotection, which opens up a new avenue for alternative therapies.

Ameliorative Effect of Citrus junos Tanaka Waste (By-Product) Water Extract on Particulate Matter 10-Induced Lung Damage

Citrus junos Tanaka (CJ)-related products are well-accepted by consumers worldwide; thus, they generate huge amounts of waste (peel, pulp, and seed) through CJ processing. Although some CJ by-products (CJBs) are recycled, their use is limited owing to the limited understanding of their nutritional and economic value. The exposure to particulate matter (PM) increases the risk of respiratory diseases. In this study, we investigated the ameliorative effects of CJB extracts (100, 200 mg/kg/day, 7 days) on PM10-induced (10 mg/kg, intranasal, 6 h) lung damage in BALB/c mice. Cell type-specific signaling pathways are examined using the A549 (PM10, 200 μg/mL, 6 h) and RAW264.7 (LPS, 100 ng/mL, 6 h) cell lines. The CJB extracts significantly attenuated PM10-induced pulmonary damage and inflammatory cell infiltration in a mouse model. The essential protein markers in inflammatory signaling pathways, such as AKT, ERK, JNK, and NF-κB for PM10-induced phosphorylation, were dramatically reduced by CJB extract treatment in both the mouse and cell models. Furthermore, the CJB extracts reduced the production of reactive oxygen species and nitric oxide in a dose-dependent manner in the cells. Comprehensively, the CJB extracts were effective in reducing PM10-induced lung injuries by suppressing pulmonary inflammation, potentially due to their anti-inflammatory and antioxidant properties.

In Silico Analysis of Peptide-Based Derivatives Containing Bifunctional Warheads Engaging Prime and Non-Prime Subsites to Covalent Binding SARS-CoV-2 Main Protease (Mpro)

Despite the progress of therapeutic approaches for treating COVID-19 infection, the interest in developing effective antiviral agents is still high, due to the possibility of the insurgence of viable SARS-CoV-2-resistant strains. Accordingly, in this article, we describe a computational protocol for identifying possible SARS-CoV-2 Mpro covalent inhibitors. Combining several in silico techniques, we evaluated the potential of the peptide-based scaffold with different warheads as a significant alternative to nitriles and aldehyde electrophilic groups. We rationally designed four potential inhibitors containing difluorstatone and a Michael acceptor as warheads. In silico analysis, based on molecular docking, covalent docking, molecular dynamics simulation, and FEP, indicated that the conceived compounds could act as covalent inhibitors of Mpro and that the investigated warheads can be used for designing covalent inhibitors against serine or cysteine proteases such as SARS-CoV-2 Mpro. Our work enriches the knowledge on SARS-CoV-2 Mpro, providing a novel potential strategy for its inhibition, paving the way for the development of effective antivirals.

Compendium of naringenin: potential sources, analytical aspects, chemistry, nutraceutical potentials and pharmacological profile

Naringenin is flavorless, water insoluble active principle belonging to flavanone subclass. It exhibits a diverse pharmacological profile as well as divine nutraceutical values. Although several researchers have explored this phytoconstituent to evaluate its promising properties, still it has not gained recognition at therapeutic levels and more clinical investigations are still required. Also the neutraceutical potential has limited marketed formulations. This compilation includes the description of reported therapeutic potentials of naringenin in variety of pathological conditions alongwith the underlying mechanisms. Details of various analytical investigations carried on this molecule have been provided along with brief description of chemistry and structural activity relationship. In the end, various patents filed and clinical trial data has been provided. Naringenin has revealed promising pharmacological activities including cardiovascular diseases, neuroprotection, anti-diabetic, anticancer, antimicrobial, antiviral, antioxidant, anti-inflammatory and anti-platelet activity. It has been marketed in the form of nanoformulations, co-crystals, solid dispersions, tablets, capsules and inclusion complexes. It is also available in various herbal formulations as nutraceutical supplement. There are some pharmacokinetic issue with naringenin like poor absorption and low dissolution rate. Although these issues have been sorted out upto certain extent still further research to investigate the bioavailability of naringenin from herbal supplements and its clinical efficacy is essential.

New Synthetic Analogues of Natural Polyphenols as Sirtuin 1-Activating Compounds

NAD⁺-dependent deacetylase SIRT1 regulates many different biological processes, thus being involved in pathogenic conditions such as metabolic diseases, neurogenerative disorders and cancer. Notably, experimental evidence underlined that the activation of SIRT1 had promising cardioprotective effects. Consequently, many efforts have been so far devoted to finding new SIRT1 activators, both derived from natural sources or prepared by synthetic procedures. Herein, we discovered new SIRT1-activating derivatives, characterized by phenolic rings spaced by sulfur, nitrogen or oxygen-based central linkers. The newly synthesized derivatives were analyzed in enzymatic assays to determine their ability to activate SIRT1, as compared with that of resveratrol. Among the tested molecules, bisarylaniline compound 10 proved to be the most efficient SIRT1 activator. An evaluation of the effects caused by focused structural variations revealed that its para-hydroxy-substituted diphenyl moiety of 10 was the fundamental structural requirement for achieving good SIRT1 activation. Compound 10 was further investigated in ex vivo studies in isolated and perfused rat hearts submitted to ischemia/reperfusion (I/R), where it showed significant protection of the myocardium against I/R injury. Molecular modeling studies suggest the binding mode of 10 within SIRT1 in the presence of the p53-AMC peptide. Our findings reveal that this chemical scaffold may be used as the starting point to develop a new class of more potent SIRT1 activators as cardioprotective agents.

Supplementation with a Cocoa-Carob Blend, Alone or in Combination with Metformin, Attenuates Diabetic Cardiomyopathy, Cardiac Oxidative Stress and Inflammation in Zucker Diabetic Rats

Diabetic cardiomyopathy (DCM) is one of the main causes of mortality among diabetic patients, with oxidative stress and inflammation major contributors to its development. Dietary flavonoids show strong antioxidant and anti-inflammatory activities, although their potential additive outcomes in combination with antidiabetic drugs have been scarcely explored. The present study investigates the cardioprotective effects of a cocoa–carob blend (CCB) diet, rich in flavonoids, alone or in combination with metformin, in the development of DCM. Zucker diabetic fatty rats (ZDF) were fed with a CCB rich-diet or a control diet, with or without metformin for 12 weeks. Glucose homeostasis, cardiac structure and function, and oxidative and inflammatory biomarkers were analysed. CCB improved glucose homeostasis, and mitigated cardiac dysfunction, hypertrophy, and fibrosis in ZDF rats. Mechanistically, CCB counteracted oxidative stress in diabetic hearts by down-regulating NADPH oxidases, reducing reactive oxygen species (ROS) generation and modulating the sirtuin-1 (SIRT1)/ nuclear factor E2-related factor 2 (Nrf2) signalling pathway, overall improving antioxidant defence. Moreover, CCB suppressed inflammatory and fibrotic reactions by inhibiting nuclear factor kappa B (NFκB) and pro-inflammatory and pro-fibrotic cytokines. Noteworthy, several of these effects were further improved in combination with metformin. Our results demonstrate that CCB strongly prevents the cardiac remodelling and dysfunction observed in diabetic animals, highlighting its potential, alone or in adjuvant therapy, for treating DCM.

Virtual Combinatorial Library Screening of Quinadoline B Derivatives against SARS-CoV-2 RNA-Dependent RNA Polymerase

The unprecedented global health threat of SARS-CoV-2 has sparked a continued interest in discovering novel anti-COVID-19 agents. To this end, we present here a computer-based protocol for identifying potential compounds targeting RNA-dependent RNA polymerase (RdRp). Starting from our previous study wherein, using a virtual screening campaign, we identified a fumiquinazolinone alkaloid quinadoline B (Q3), an antiviral fungal metabolite with significant activity against SARS-CoV-2 RdRp, we applied in silico combinatorial methodologies for generating and screening a library of anti-SARS-CoV-2 candidates with strong in silico affinity for RdRp. For this study, the quinadoline pharmacophore was subjected to structural iteration, obtaining a Q3-focused library of over 900,000 unique structures. This chemical library was explored to identify binders of RdRp with greater affinity with respect to the starting compound Q3. Coupling this approach with the evaluation of physchem profile, we found 26 compounds with significant affinities for the RdRp binding site. Moreover, top-ranked compounds were submitted to molecular dynamics to evaluate the stability of the systems during a selected time, and to deeply investigate the binding mode of the most promising derivatives. Among the generated structures, five compounds, obtained by inserting nucleotide-like scaffolds (1, 2, and 5), heterocyclic thiazolyl benzamide moiety (compound 3), and a peptide residue (compound 4), exhibited enhanced binding affinity for SARS-CoV-2 RdRp, deserving further investigation as possible antiviral agents. Remarkably, the presented in silico procedure provides a useful computational procedure for hit-to-lead optimization, having implications in anti-SARS-CoV-2 drug discovery and in general in the drug optimization process.

Comparative Transcriptome Analyses of Geriatric Rats Associate Age-Related Erectile Dysfunction With a lncRNA-miRNA-mRNA Regulatory Network

BACKGROUND

The key regulatory roles of long non-coding RNAs (lncRNAs) in age-related erectile dysfunction (A-ED) are unknown.

AIM

This study aimed to identify putative lncRNAs that regulate age-related erectile dysfunction via transcriptome analyses, and to predict their specific regulatory routes via bioinformatics methods.

METHODS

22 geriatric male SD rats were divided into age-related erectile dysfunction (A-ED) and negative control (NC) groups after evaluations of intracavernous pressure (ICP). By comparative analysis of transcriptomes of cavernosal tissues from both groups, we identified differentially expressed lncRNAs, miRNAs, and mRNAs. Seven differentially expressed lncRNAs were selected and further verified by quantitative real-time polymerase chain reactions (RT-qPCR). The construction of the lncRNA-miRNA-mRNA network, the Gene Ontology (GO) term enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed in Cytoscape.

RESULTS

From comparative transcriptome analyses of A-ED and NC groups, 69, 29, and 364 differentially expressed lncRNAs, miRNAs, and mRNAs were identified respectively. Differentially expressed lncRNAs were culled to seven, which were all verified by qPCR. Three of these lncRNAs (ENSRNOT00000090050, ENSRNOT00000076482, and ENSRNOT00000029245) were used to build regulatory networks, of which only ENSRNOT00000029245 was successful. Moreover, GO and KEGG analyses demonstrated that these lncRNAs possibly regulated muscle myosin complex, muscle cell cellular homeostasis, and ultimately erectile function in rats through PI3K-Akt, fluid shear stress, and atherosclerosis pathways.

CONCLUSION

Our study identified differentially expressed lncRNAs, miRNAs, and mRNAs through comparisons of transcriptomes of geriatric rats. An identified lncRNA verified by qPCR, was used to construct a lncRNA-miRNA-mRNA regulatory network. LncRNA ENSRNOT00000029245 possibly regulated downstream mRNAs through this regulatory network, leading to apoptosis in the cavernous tissue, fibrosis, and endothelial dysfunction, which ultimately caused ED. These findings provide seminal insights into the molecular biology of aging-related ED, which could spur the development of effective therapeutics.

Identification of novel SIRT1 activators endowed with cardioprotective profile

Drugs targeting epigenetic mechanisms are attracting the attention of scientists since it was observed that the modulation of this post-translational apparatus, could help to identify innovative therapeutic strategies. Among the epigenetic druggable targets, the positive modulation of SIRT1 has also been related to significant cardioprotective effects. Unfortunately, actual SIRT1 activators (natural products and synthetic molecules) suffer from several drawbacks, particularly poor pharmacokinetic profiles. Accordingly, in this article we present the development of an integrated screening platform aimed at identifying novel SIRT1 activators with favorable drug-like features as cardioprotective agents. Encompassing several competencies (in silico, medicinal chemistry, and pharmacology), we describe a multidisciplinary approach for rapidly identifying SIRT1 activators and their preliminary pharmacological characterization. In the first step, we virtually screened an in-house chemical library comprising synthetic molecules inspired by nature, against SIRT1 enzyme. To this end, we combined molecular docking-based approach with the estimation of relative ligand binding energy, using the crystal structure of SIRT1 enzyme in complex with resveratrol. Eleven computational hits were identified, synthesized and tested against the isolated enzyme for validating the in silico strategy. Among the tested molecules, five of them behave as SIRT1 enzyme activators. Due to the superior response in activating the enzyme and its favorable calculated physico-chemical properties, compound 8 was further characterized in ex vivo studies on isolated and perfused rat hearts submitted to ischemia/reperfusion (I/R) period. The pharmacological profile of compound 8, suggests that this molecule represents a prototypic SIRT1 activator with satisfactory drug-like profile, paving the way for developing novel epigenetic cardioprotective agents.

Anticancer potential of Naringenin, Biosynthesis, Molecular target, and structural perspectives

Numerous novel medicinal agents isolated from plant sources were used as indigenous remedies for the management and treatment of various types of cancer diseases. Naringenin is a naturally occurring flavanone glycoside and aglycone (genin) moiety of naringin, predominantly found in citrus and grapefruits, has emerged as a potential therapeutic agent for the management of a variety of diseases. A huge number of scientific papers have been published on naringenin describing its detailed studies and its therapeutic application in different diseases. The current study highlights, a comprehensive study on naringenin concerning its biosynthesis, molecular targets/pathways involved in carcinogenesis, mechanism of actions (MOAs), and structure-activity relationships (SARs), and patents granted have been highlighted. Naringenin and its derivatives has remarkable anti-cancer activity due to their inhibitory potential against diverse targets namely ABCG2/P-gp/BCRP, 5a-reductase, 17-bhydroxysteroid dehydrogenase, aromatase, proteasome, HDAC/Situin-1, VEGF, VEGFR-2 kinase, MMP-2/9, JAK/STAT signaling pathways, CDC25B, tubulin, topoisomerase-II, cathepsin-K, Wnt, NF-kB, B-Raf and mTOR, etc. With the huge knowledge of molecular targets, structural intuition, and SARs, the current study may be beneficial to design more potent, safe, effective, and economic anti-cancer naringenin. This is concluded that naringenin is a promising natural product for the management and therapy of cancer. Further evolution for pharmacological importance, clinical research, and trials are required to manifest its therapeutic action on metabolic syndrome in the human community.

Targeting Sirtuin1 to treat aging-related tissue fibrosis: From prevention to therapy

Fibrosis, which is characterized by excessive extracellular matrix (ECM) deposition, is a wound-healing response to organ injury and may promote cancer and failure in various organs, such as the heart, liver, lung, and kidney. Aging associated with oxidative stress and inflammation exacerbates cellular dysfunction, tissue failure, and body function disorders, all of which are closely related to fibrosis. Sirtuin-1 (SIRT1) is a class III histone deacetylase that regulates growth, transcription, aging, and metabolism in various organs. This protein is downregulated in organ injury and fibrosis associated with aging. Its expression and distribution change with age in different organs and play critical roles in tissue oxidative stress and inflammation. This review first described the background on fibrosis and regulatory functions of SIRT1. Second, we summarized the relationships of SIRT1 with other proteins and its protective action during fibrosis in the heart, liver, lung and kidney. Third, the activation of SIRT1 in therapies of tissue fibrosis, especially in liver fibrosis and aging-related tissue injury, was analyzed. In conclusion, SIRT1 targeting may be a new therapeutic strategy in fibrosis.

Cardiac senescence is alleviated by the natural flavone acacetin via enhancing mitophagy

Cardiac senescence is associated with cardiomyopathy which is a degenerative disease in the aging process of the elderly. The present study investigates using multiple experimental approaches whether the natural flavone acacetin could attenuate myocardial senescence in C57/BL6 mice and H9C2 rat cardiac cells induced by D-galactose. We found that the impaired heart function in D-galactose-induced accelerated aging mice was improved by oral acacetin treatment in a dose-dependent manner. Acacetin significantly countered the increased serum advanced glycation end products, the myocardial telomere length shortening, the increased cellular senescence marker proteins p21 and p53, and the reduced mitophagy signaling proteins PINK1/Parkin and Sirt6 expression in aging mice. In H9C2 rat cardiac cells, acacetin alleviated cell senescence induced by D-galactose in a concentration-dependent manner. Acacetin decreased p21 and p53 expression, up-regulated PINK1/Parkin, LC3II/LC3I ratio, pLKB1, pAMPK and Sirt6, and reversed the depolarized mitochondrial membrane potential in aging cardiac cells. Mitophagy inhibition with 3-methyladenine or silencing Sirt6 abolished the protective effects of acacetin against cardiac senescence. Further analysis revealed that acacetin effect on Sirt6 was mediated by Sirt1 activation and increase of NAD+/NADH ratio. These results demonstrate that acacetin significantly inhibits in vivo and in vitro cardiac senescence induced by D-galactose via Sirt1-mediated activation of Sirt6/AMPK signaling pathway, thereby enhancing mitophagy and preserving mitochondrial function, which suggests that acacetin may be a drug candidate for treating cardiovascular disorders related to aging.

Predictive Value of Sirtuins in Acute Myocardial Infarction - Bridging the Bench to the Clinical Practice

Acute myocardial infarction (AMI) is a non-transmissible condition with high prevalence, morbidity, and mortality. Different strategies for the management of AMI are employed worldwide, but its early diagnosis remains a major challenge. Many molecules have been proposed in recent years as predictive agents in the early detection of AMI, including troponin (C, T, and I), creatine kinase MB isoenzyme, myoglobin, heart-type fatty acid-binding protein, and a family of histone deacetylases with enzymatic activities named sirtuins. Sirtuins may be used as predictive or complementary treatment strategies and the results of recent preclinical studies are promising. However, human clinical trials and data are scarce, and many issues have been raised regarding the predictive values of sirtuins. The present review summarizes research on the predictive value of sirtuins in AMI. We also briefly summarize relevant clinical trials and discuss future perspectives and possible clinical applications.

Bioactive Compounds from Germinated Brown Rice Protect Cardiomyocytes Against Simulated Ischemic/Reperfusion Injury by Ameliorating Mitochondrial Dysfunction

Purpose

Ischemic/reperfusion (I/R) injury is the principal mechanism during Ischemic Heart Disease (IHD). The key modulator of I/R injury is dysregulation of mitochondria function. Germinated Brown Rice (GBR) has been recommended as a bio-functional food and has clarified the potential properties in several effects. However, the effect of GBR mediated cardioprotective properties, focusing on mitochondrial function’s role, remains unexplored. Thus, this study aims to investigate the cardioprotective effects of GBR pretreatment against simulated I/R injury.

Methods

H9c2 cardiomyocytes were incubated with GBR at a five ƞg/mL concentration for 24 hours and simulated I/R (sI/R) for 40 minutes. Cell viability and cell apoptosis were assessed by 7-AAD staining and Annexin V/PI staining, respectively. The mitochondrial membrane potential was determined by JC-1 staining and mitochondrial respiration represented by oxygen consumption rate (OCR) using Seahorse Flux analyzer.

Results

The results revealed that the administration of GBR before sI/R significantly decreased the percentage of cell death and total cell apoptosis in H9c2 during stimulation of ischemic/reperfusion. Besides, pretreatment of cardiomyocytes with GBR remarkably stabilized mitochondrial membrane potential and improved impaired mitochondrial respiration in simulated-H9c2 injury.

Conclusion

The present research is the first study to report the effective cardioprotection of GBR. Pretreatment of GBR potentially protects H9c2 cardiomyocytes against sI/R injury through mitochondrial function. The underlying therapeutic activities are possibly associated with its bio-functional compounds. However, the underlying mechanism on the cardioprotective effects of GBR needs further studies.

Sirtuins and the circadian clock interplay in cardioprotection: focus on sirtuin 1

Chronic disruption of circadian rhythms which include intricate molecular transcription-translation feedback loops of evolutionarily conserved clock genes has serious health consequences and negatively affects cardiovascular physiology. Sirtuins (SIRTs) are nuclear, cytoplasmic and mitochondrial histone deacetylases that influence the circadian clock with clock-controlled oscillatory protein, NAMPT, and its metabolite NAD+. Sirtuins are linked to the multi-organ protective role of melatonin, particularly in acute kidney injury and in cardiovascular diseases, where melatonin, via upregulation of SIRT1 expression, inhibits the apoptotic pathway. This review focuses on SIRT1, an NAD+-dependent class III histone deacetylase which counterbalances the intrinsic histone acetyltransferase activity of one of the clock genes, CLOCK. SIRT1 is involved in the development of cardiomyocytes, regulation of voltage-gated cardiac sodium ion channels via deacetylation, prevention of atherosclerotic plaque formation in the cardiovascular system, protection against oxidative damage and anti-thrombotic actions. Overall, SIRT1 has a see-saw effect on cardioprotection, with low levels being cardioprotective and higher levels leading to cardiac hypertrophy.

Retinal Neurodegeneration: Correlation between Nutraceutical Treatment and Animal Model

Retinal diseases can be induced by a variety of factors, including gene mutations, environmental stresses and dysmetabolic processes. The result is a progressive deterioration of visual function, which sometimes leads to blindness. Many treatments are under investigation, though results are still mostly unsatisfactory and restricted to specific pathologies, particularly in the case of gene therapy. The majority of treatments have been tested in animal models, but very few have progressed to human clinical trials. A relevant approach is to study the relation between the type of treatments and the degenerative characteristics of the animal model to better understand the effectiveness of each therapy. Here we compare the results obtained from different animal models treated with natural compounds (saffron and naringenin) to anticipate the potentiality of a single treatment in different pathologies.

Promotion of Momordica Charantia polysaccharides on neural stem cell proliferation by increasing SIRT1 activity after cerebral ischemia/reperfusion in rats

The deacetylase SIRT1 has been reported to play a critical role in regulating neurogenesis, which may be an adaptive processes contributing to recovery after stroke. Our previous work showed that the antioxidant capacity of Momordica charantia polysaccharides (MCPs) could protect against cerebral ischemia/reperfusion (I/R) after stroke. However, whether the protective effect of MCPs on I/R injury is related to neural stem cell (NSC) proliferation remains unclear. In the present study, we designed invivo and invitro experiments to elucidate the underlying mechanisms by which MCPs promote endogenous NSC proliferation during cerebral I/R. Invivo results showed that MCPs rescued the memory and learning abilities of rats after I/R damage and enhanced NSC proliferation in the rat subventricular zone (SVZ) and subgrannular zone (SGZ) during I/R. Invitro experiments demonstrated that MCPs could stimulate the proliferation of C17.2 cells under oxygen-glucose deprivation (OGD) conditions. Further studies revealed that the proliferation-promoting mechanism of MCPs relied on increasing the activity of SIRT1, decreasing the level of acetylation of β-catenin in the cytoplasm, and then triggering the translocation of β-catenin into the nucleus. These data provide experimental evidence that the up-regulation of SIRT1 activity by MCPs led to an increased cytoplasmic deacetylation of β-catenin, which promoted translocation of β-catenin to the nucleus to participate in the signaling pathway involved in NSC proliferation. The present study reveals that MCPs function as a therapeutic drug to promote stroke recovery by increasing the activity of SIRT1, decreasing the level of acetylated β-catenin, promoting the nuclear translocation of β-catenin and thereby increasing endogenous NSC proliferation.

Naringenin Ameliorates Chronic Sleep Deprivation-Induced Pain via Sirtuin1 Inhibition

Growing experimental evidences have suggested the reciprocal correlation between sleep deprivation and pain. Inflammation and oxidative stress are among the key pathways underlying this correlation. Therefore, the present study was aimed to assess the effect of antioxidant and anti-inflammatory compound naringenin (NGN) against chronic sleep deprivation (CSD)-induced mechanical and thermal hyperalgesia in female Swiss albino mice. In this study, mice were chronically sleep-deprived for 8 h a day for five days a week with the weekend as a free sleep period and continued for nine weeks using a modified multiple platform method. The pain behavioral tests were conducted at the end of the fourth week to assess the development of hyperalgesia followed by the administration of NGN and a combination of NGN with Sirtinol (SIR, a sirtuin1 inhibitor) till the end of the study. After nine weeks, pain behavioral tests, along with oxidative stress and inflammatory parameters in cortex and striatum, were assessed. Results indicated that CSD-induced hyperalgesia in mice accompanied by increased oxidative stress and inflammatory markers in cortex and striatum of the brain. NGN combatted the hyperalgesic response and also decreased levels of oxidative stress and inflammatory markers. Furthermore, the pharmacological effect of NGN was mitigated with SIR. Thus, the findings of the present study reveal that NGN is acting via sirtuin1 to exert its antinociceptive activity against CSD-induced hyperalgesia.

Naringenin alleviates nonalcoholic steatohepatitis in middle-aged Apoe-/-mice: role of SIRT1

BACKGROUND

Naringenin is naturally isolated from citrus fruits possessing many pharmacological activities. However, little is known about the effect of naringenin on nonalcoholic steatohepatitis (NASH) in the model of metabolic syndrome.

PURPOSE

The present study is aimed to investigate the effect of naringenin on NASH in 12-mo-old male ApoE-/- mice and its possible underlying mechanism.

METHODS

In vivo, 12-mo-old male ApoE-/- mice were administrated with naringenin by intragastric gavage for 12 weeks. At the end of experiment, the blood samples and liver tissues were collected. Metabolic parameters in serum, levels of triglyceride, cholesterol and hydroxyproline, activities of antioxidant enzymes, and content of inflammatory cytokines (TNF-α and IL-6) in liver were examined by corresponding assay kits. Pathological changes in liver were observed by hematoxylin-eosin, oil red O, masson's trichrome, picro-sirius red and senescence β-galactosidase staining. Dihydroethidium was used for detection of reactive oxygen species (ROS). In vitro, AML-12 cells were treated with oleic acid in the presence or absence of naringenin for 24 h. Transfection of SIRT1 siRNA was also conducted in vitro. Lipid accumulation, cellular ROS generation, malondialdehyde content, antioxidant enzyme activities and secretion levels of TNF-α and IL-6 were examined. Both in vivo and in vitro, gene expressions were detected by real-time PCR or western blot.

RESULTS

Naringenin administration improved metabolic parameters, suppressed hepatic steatosis, regulated expression of genes involved in lipid metabolism (FASN, SCD1, PPARα and CPT1α), reduced hepatic fibrosis and cell senescence, inhibited hepatic inflammation as evidenced by the decreased macrophage recruitment and content of TNF-α and IL-6, and reduced hepatic oxidative stress by suppressing ROS generation and normalizing activities of antioxidant enzymes. Notably, naringenin administration increased hepatic SIRT1 protein expression and activity along with the increased deacetylation of liver kinase B1 (LKB1), PGC1α and NF-κB. In vitro study, the benefits of naringenin on lipid accumulation, oxidative stress and inflammation were diminished by SIRT1 siRNA transfection.

CONCLUSIONS

These results indicate that naringenin administration may be a potential curative therapy for NASH treatment and the activation of hepatic SIRT1-mediated signaling cascades is involved in its beneficial effects.

Naringenin protects RPE cells from NaIO3-induced oxidative damage in vivo and in vitro through up-regulation of SIRT1

BACKGROUND

Dry age-related macular degeneration (dAMD) leads to serious burden of visual impairment and there is no definitive treatment. Previous studies have showed that naringenin (NAR) significantly increased electroretinography (ERG) c-wave in sodium iodate (NaIO₃)-treated rats and viability of NaIO₃-treated ARPE-19 cells. But the underlying mechanism is still unknown.

PURPOSE

We tested the hypothesis that anti-oxidation mediated by Sirtuin 1 (SIRT1) was important to the protective effect of NAR on dAMD.

STUDY DESIGN/METHODS

NaIO₃-induced mice retinopathy and ARPE-19 cells injury models were established. In vivo, the protective effect of NAR eye drops on retina was evaluated by flash ERG (FERG) recording and histopathological examination. In vitro, viability of ARPE-19 cells, and the levels of lactic dehydrogenase (LDH), reactive oxygen species (ROS) and carbonyl protein were detected. Protein expression of SIRT1 was analyzed by immunochemical staining, immunofluorescence and western blotting.

RESULTS

NAR eye drops improved retinal function and morphology and normalized the protein expression of SIRT1 in mice exposed to NaIO₃. NAR promoted the survival of ARPE-19 cells in a concentration-dependent manner. NAR up-regulated SIRT1 protein expression, and decreased levels of ROS and carbonyl protein. Moreover, EX527, a selective inhibitor of SIRT1, abolished the effects of NAR on the cell viability and ROS. In addition, SRT1720, a selective agonist of SIRT1, improved the viability of cells and suppressed the production of ROS.

CONCLUSION

Our findings indicate that SIRT1-mediated anti-oxidation contributes to the protective effect of NAR eye drops on dAMD.

Ayahuasca Beverages: Phytochemical Analysis and Biological Properties

Ayahuasca is a psychoactive beverage, originally consumed by indigenous Amazon tribes, of which consumption has been increasing worldwide. The aim of this study was to evaluate the phytochemical profile, as well as the antioxidant, anti-inflammatory and antimicrobial properties of decoctions of four individual plants, a commercial mixture and four mixtures of two individual plants used in the Ayahuasca preparation. For this purpose, a phytochemical characterization was performed, determining the content of flavonoids, total phenolic compounds, and analyzing the phenolic profile. Besides, 48 secondary metabolites were investigated by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) and their concentration estimated with real standards when present. The antioxidant activity was evaluated by both the β-carotene bleaching test and DPPH free radical scavenging assay, and the anti-inflammatory activity was determined by a protein denaturation method. Finally, the antimicrobial properties were evaluated using the disc diffusion assay, resazurin microtiter method, anti-quorum sensing and anti-biofilm activity assays. The obtained results showed that, in general, the samples have a high content of phenolic compounds and flavonoids with noticeable differences, reflecting on remarkable antioxidant and anti-inflammatory activities. Significant antimicrobial properties were also observed, with emphasis on the effect of B. caapi and P. harmala on planktonic and biofilm cells of A. baumannii, inhibiting both the biofilm formation and the production of violacein pigment.

Ameliorative effects and mechanism of crocetin in arsenic trioxide‑induced cardiotoxicity in rats

Arsenic trioxide (ATO) is commonly used to treat patients with acute promyelocytic leukemia since it was authorized by the U.S. Food and Drug Administration in the 1970s, but its applicability has been limited by its cardiotoxic effects. Therefore, the aim of the present study was to investigate the cardioprotective effects and underlying mechanism of crocetin (CRT), the critical ingredient of saffron. Sprague-Dawley rats were then randomly divided into four groups (n=10/group): i) Control group; ii) ATO group, iii) CRT-low (20 mg/kg) group; and iv) CRT-high (40 mg/kg) group. Rats in the Control and ATO groups were intraperitoneally injected with equal volumes of 0.9% sodium chloride solution, and CRT groups were administered with either 20 and 40 mg/kg CRT. Following 6 h, all groups except the Control group were intraperitoneally injected with 5 mg/kg ATO over 10 days. Cardiotoxicity was indicated by changes in electrocardiographic (ECG) patterns, morphology and marker enzymes. Histomorphological changes in the heart tissue were observed by pathological staining. The levels of superoxide dismutase, glutathione peroxidase, malondialdehyde and catalase in the serum were analyzed using colometric commercial assay kits, and the levels of reactive oxygen species in the heart tissue were detected using the fluorescent probe dihydroethidium. The expression levels of inflammatory factors and activities of apoptosis-related proteins were analyzed using immunohistochemistry. The protein expression levels of silent information regulator of transcription 1 were measured using western blotting. Cardiotoxicity was induced in male Sprague-Dawley rats with ATO (5 mg/kg). CRT (20 and 40 mg/kg) and ATO were co-administered to evaluate possible cardioprotective effects. CRT significantly reduced the heart rate and J-point elevation induced by ATO in rats. Histological changes were evaluated via hematoxylin and eosin staining. CRT decreased the levels of creatine kinase and lactate dehydrogenase, increased the activities of superoxide dismutase, glutathione-peroxidase and catalase, and decreased the levels of malondialdehyde and reactive oxygen species. Moreover, CRT downregulated the expression levels of the pro-inflammatory factors IL-1, TNF-α, IL-6, Bax and p65, as well as increased the expression of Bcl-2. It was also identified that CRT enhanced silent information regulator of transcription 1 protein expression. Thus, the present study demonstrated that CRT treatment effectively ameliorated ATO-induced cardiotoxicity. The protective effects of CRT can be attributed to the inhibition of oxidative stress, inflammation and apoptosis. Therefore, CRT represents a promising therapeutic method for improving the cardiotoxic side effects caused by ATO treatment, and additional clinical applications are possible, but warrant further investigation.

Oxidative Stress and New Pathogenetic Mechanisms in Endothelial Dysfunction: Potential Diagnostic Biomarkers and Therapeutic Targets

Cardiovascular diseases (CVD), including heart and pathological circulatory conditions, are the world's leading cause of mortality and morbidity. Endothelial dysfunction involved in CVD pathogenesis is a trigger, or consequence, of oxidative stress and inflammation. Endothelial dysfunction is defined as a diminished production/availability of nitric oxide, with or without an imbalance between endothelium-derived contracting, and relaxing factors associated with a pro-inflammatory and prothrombotic status. Endothelial dysfunction-induced phenotypic changes include up-regulated expression of adhesion molecules and increased chemokine secretion, leukocyte adherence, cell permeability, low-density lipoprotein oxidation, platelet activation, and vascular smooth muscle cell proliferation and migration. Inflammation-induced oxidative stress results in an increased accumulation of reactive oxygen species (ROS), mainly derived from mitochondria. Excessive ROS production causes oxidation of macromolecules inducing cell apoptosis mediated by cytochrome-c release. Oxidation of mitochondrial cardiolipin loosens cytochrome-c binding, thus, favoring its cytosolic release and activation of the apoptotic cascade. Oxidative stress increases vascular permeability, promotes leukocyte adhesion, and induces alterations in endothelial signal transduction and redox-regulated transcription factors. Identification of new endothelial dysfunction-related oxidative stress markers represents a research goal for better prevention and therapy of CVD. New-generation therapeutic approaches based on carriers, gene therapy, cardiolipin stabilizer, and enzyme inhibitors have proved useful in clinical practice to counteract endothelial dysfunction. Experimental studies are in continuous development to discover new personalized treatments. Gene regulatory mechanisms, implicated in endothelial dysfunction, represent potential new targets for developing drugs able to prevent and counteract CVD-related endothelial dysfunction. Nevertheless, many challenges remain to overcome before these technologies and personalized therapeutic strategies can be used in CVD management.

Development of Fortified Citrus Olive Oils: From Their Production to Their Nutraceutical Properties on the Cardiovascular System

: Recently the use of food by-products as natural sources of biologically active substances has been extensively investigated especially for the development of functional foods fortified with natural antioxidants. Due to their content of bioactive compounds, such as carotenoids, flavonoids and limonoids, citrus peels could be suitable to formulate enriched olive oils able to boost healthy nutrition. The aim of this study was: (i) to determine the compositional and sensory profiles of citrus olive oil; and (ii) to evaluate its nutraceutical properties in rats with high fat diet-induced metabolic syndrome and oxidative stress. The results obtained show the potential of using citrus peels as a source of bioactive compounds to improve the sensory profile as well as the phytochemical composition of olive oil. We demonstrated that the production system of Citrus x aurantium olive oil and Citrus limon olive oil improves its organoleptic properties without altering its beneficial effects, which, like control extra virgin olive oil, showed protective effects relating to glucose and serum lipid levels, metabolic activity of adipocytes, myocardial tissue functionality, oxidative stress markers and endothelial function at blood vessel level.

Phenolic Compounds Exerting Lipid-Regulatory, Anti-Inflammatory and Epigenetic Effects as Complementary Treatments in Cardiovascular Diseases

Atherosclerosis is the main process behind cardiovascular diseases (CVD), maladies which continue to be responsible for up to 70% of death worldwide. Despite the ongoing development of new and potent drugs, their incomplete efficacy, partial intolerance and numerous side effects make the search for new alternatives worthwhile. The focus of the scientific world turned to the potential of natural active compounds to prevent and treat CVD. Essential for effective prevention or treatment based on phytochemicals is to know their mechanisms of action according to their bioavailability and dosage. The present review is focused on the latest data about phenolic compounds and aims to collect and correlate the reliable existing knowledge concerning their molecular mechanisms of action to counteract important risk factors that contribute to the initiation and development of atherosclerosis: dyslipidemia, and oxidative and inflammatory-stress. The selection of phenolic compounds was made to prove their multiple benefic effects and endorse them as CVD remedies, complementary to allopathic drugs. The review also highlights some aspects that still need clear scientific explanations and draws up some new molecular approaches to validate phenolic compounds for CVD complementary therapy in the near future.