Quercetin suppresses cyclooxygenase-2 expression and angiogenesis through inactivation of P300 signaling

Screening and identification of Euphorbiae pekinensis Rupr. anti-angiogenic multi-components with UPLC-QTOF-MS in zebrafish

Euphorbia pekinensis Rupr. (EP) (Euphorbiaceae), as Traditional Chinese Medicine (TCM), exhibits therapeutic effects on tumors in clinical practice. Anti-angiogenesis may be an underlying molecular mechanism of EP's actions. However, the anti-angiogenic active ingredients of EP remain unclear. The screening and analysis of anti-angiogenic agents were essential for the sufficient utilization and development of EP. Thus, we established a UPLC-QTOF-MS method based on a transgenic zebrafish model to screen anti-angiogenesis activity components in EP. UPLC-QTOF-MS was used to characterize compounds from EP and in vivo compounds in Tg (flk1: mCherry) zebrafish larvae treated with EP. Based on the identification results, five components were selected, and their anti-angiogenesis activity were investigated via assessment of intersegmental blood vessels during the development of the transgenic zebrafish. Three of these components (3,3'-O-dimethoxy ellagic acid, quercetin, and ingenol) are active components of EP with anti-angiogenic effects. Among them, 3, 3'-O-dimethoxy ellagic acid and ingenol were first demonstrated with anti-angiogenesis effects. UPLC-PDA analysis was performed on EP water extracts to determine anti-angiogenesis active ingredients quantitatively. In the concentration range of 100-200 μg/mL, EP and the active ingredient compositions, mixed according to the content of EP, had equivalent anti-angiogenesis activities. These experimental results indicate that the UPLC-QTOF-MS method, combined with a transgenic zebrafish model, is rapid, sensitive and reliable. The combination in TCM offers the potential to achieve certain effect levels with lower concentrations of the individual compound.

Molecular Targets of Natural Compounds with Anti-Cancer Properties

Cancer is the second leading cause of death in humans. Despite rapid developments in diagnostic methods and therapies, metastasis and resistance to administrated drugs are the main obstacles to successful treatment. Therefore, the main challenge should be the diagnosis and design of optimal therapeutic strategies for patients to increase their chances of responding positively to treatment and increase their life expectancy. In many types of cancer, a deregulation of multiple pathways has been found. This includes disturbances in cellular metabolism, cell cycle, apoptosis, angiogenesis, or epigenetic modifications. Additionally, signals received from the microenvironment may significantly contribute to cancer development. Chemical agents obtained from natural sources seem to be very attractive alternatives to synthetic compounds. They can exhibit similar anti-cancer potential, usually with reduced side effects. It was reported that natural compounds obtained from fruits and vegetables, e.g., polyphenols, flavonoids, stilbenes, carotenoids and acetogenins, might be effective against cancer cells in vitro and in vivo. Several published results indicate the activity of natural compounds on protein expression by its influence on transcription factors. They could also be involved in alterations in cellular response, cell signaling and epigenetic modifications. Such natural components could be used in our diet for anti-cancer protection. In this review, the activities of natural compounds, including anti-cancer properties, are described. The influence of natural agents on cancer cell metabolism, proliferation, signal transduction and epigenetic modifications is highlighted.

Quercetin Preserves Oral Cavity Health by Mitigating Inflammation and Microbial Dysbiosis

Failure to attenuate inflammation coupled with consequent microbiota changes drives the development of bone-destructive periodontitis. Quercetin, a plant-derived polyphenolic flavonoid, has been linked with health benefits in both humans and animals. Using a systematic approach, we investigated the effect of orally delivered Quercetin on host inflammatory response, oral microbial composition and periodontal disease phenotype. In vivo, quercetin supplementation diminished gingival cytokine expression, inflammatory cell infiltrate and alveolar bone loss. Microbiome analyses revealed a healthier oral microbial composition in Quercetin-treated versus vehicle-treated group characterized by reduction in the number of pathogenic species including Enterococcus, Neisseria and Pseudomonas and increase in the number of non-pathogenic Streptococcus sp. and bacterial diversity. In vitro, Quercetin diminished inflammatory cytokine production through modulating NF-κB:A20 axis in human macrophages following challenge with oral bacteria and TLR agonists. Collectively, our findings reveal that Quercetin supplement instigates a balanced periodontal tissue homeostasis through limiting inflammation and fostering an oral cavity microenvironment conducive of symbiotic microbiota associated with health. This proof of concept study provides key evidence for translational studies to improve overall health.

Quercetin Prevents LPS-Induced Oxidative Stress and Inflammation by Modulating NOX2/ROS/NF-kB in Lung Epithelial Cells

Oxidative stress caused by the production of reactive oxygen species (ROS) plays a major role in inflammatory processes. We hypothesized that modulation of ROS via quercetin may protect against oxidative stress and inflammation. Thus, this study aimed to investigate the effects of quercetin on oxidative stress and inflammation in lung epithelial A549 cells. The lipopolysaccharide (LPS)-induced elevation of intracellular ROS levels was reduced after quercetin treatment, which also almost completely abolished the mRNA and protein expression of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) induced by LPS stimulation. In addition, quercetin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and reduced levels of inflammatory cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6, which had increased significantly after LPS exposure. Our data demonstrated that quercetin decreased ROS-induced oxidative stress and inflammation by suppressing NOX2 production.

Nutraceuticals and their role in tumor angiogenesis

Angiogenesis plays a pivotal role in cancer initiation, maintenance, and progression. Diet may inhibit, retard or reverse these processes affecting angiogenesis (angioprevention). Nutraceuticals, such as omega-3 fatty acids, amino acids, proteins, vitamins, minerals, fibers, and phenolic compounds, improve health benefits as they are a source of bioactive compounds that, among other effects, can regulate angiogenesis. The literature concerning the pro-angiogenic and/or anti-angiogenic nutraceuticals and the possible activated pathways in cancer and other non-neoplastic diseases by in vivo and in vitro experiments are reviewed.

Network Pharmacology-Based Dissection of the Comprehensive Molecular Mechanisms of the Herbal Prescription FDY003 Against Estrogen Receptor-Positive Breast Cancer

Estrogen receptor-positive breast cancer (ERPBC) is the commonest subtype of breast cancer, with a high prevalence, incidence, and mortality. Herbal drugs are increasingly being used to treat ERPBC, although their mechanisms of action are not fully understood. Therefore, in this study, we aimed to analyze the therapeutic properties of FDY003, a herbal anti-ERPBC prescription, using a network pharmacology approach. FDY003 decreased the viability of human ERPBC cells and sensitized them to tamoxifen, an endocrine drug that is widely used in the treatment of ERPBC. The network pharmacology analysis revealed 18 pharmacologically active components in FDY003 that may interact with and regulate 66 therapeutic targets. The enriched gene ontology terms for the FDY003 targets were associated with the modulation of cell survival and death, cell proliferation and growth arrest, and estrogen-associated cellular processes. Analysis of the pathway enrichment of the targets showed that FDY003 may target a variety of ERPBC-associated pathways, including the PIK3-Akt, focal adhesion, MAPK, and estrogen pathways. Overall, these data provide a comprehensive mechanistic insight into the anti-ERPBC activity of FDY003.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Anti-Inflammatory, Antioxidant, Chemical Characterization, and Safety Assessment of Argania spinosa Fruit Shell Extract from South-Western Morocco

Argania spinosa (L.) plays an important role in the Moroccan agroeconomy, providing both employment and export revenue. Argan oil production generates different by-products with functionalities that are not yet investigated, in particular, the shell fruit. The present study aims, for the first time, at evaluating the acute and subacute toxicity, anti-inflammatory, and antioxidant effects of argan fruit shell ethanol extract (AFSEE). The LD₅₀ of AFSEE was determined to be greater than the 5000 mg/kg body weight of mice. No significant variation in the body and organ weights was observed after 28 days of AFSEE treatment compared to that of the control group. Biochemical parameters and histopathological examination revealed no toxic effects of AFSEE. The AFSEE produced a significant inhibition of xylene-induced ear edema in mice. AFSEE reduced significantly the paw edema in mice after carrageenan injection. The chemical characterization showed that AFSEE contains a high level of total phenol content, flavonoids, condensed tannins, and flavanols. The obtained IC₅₀ of DPPH, ABTS, reducing power, and β-carotene demonstrates that AFSEE has a potential antioxidant effect. The results indicate that AFSEE was safe and nontoxic to mice even at higher doses. Furthermore, the present findings demonstrate that AFSEE has potential anti-inflammatory and antioxidant activities.

Topical onion juice mitigates the morphological alterations of the cornea in the aged male rats

Aging is associated with structural and functional changes of the cornea. Fresh onion juice contains phenolic compounds and flavonoids that may provide an anti-aging effect. The aim of this study was to assess the ability of the onion juice to ameliorate these aging changes. Rats were grouped as adult and aged groups. Rats of both groups received eye drops of diluted onion juice in their right eyes every 8 hours for 12 weeks, while the left ones were served as control eyes. The corneas of both eyes underwent histopathological, immunohistochemical and morphometric assessments, in addition to measuring their intraocular pressure (IOP). The aged group exhibited a significantly elevated IOP, decreased tear secretion, degenerated corneal epithelium and endothelium, surface erosions and stromal edema with irregular collagen fibers. Administration of onion juice led to lowering of IOP, significant increase in tearing, restoration of most of epithelial, endothelial and stromal integrity, and increased epithelial, keratocystic and endothelial cell densities. Immunohistochemically, the epithelium and endothelium revealed positive immune reactions for both epidermal growth factor receptor (EGFR) and paired box protein-6 (PAX6) in the control and onion-treated corneas of the adult group, while these immune reactions were negative in the untreated aged ones. Onion drops in aged corneas showed a positive immune reaction for EFGR and PAX6 involving the epithelial and endothelial layers. In conclusion, topical onion juice improves corneal aging changes through its direct effect, and indirectly through lowering IOP and enhancing tear secretion.

Emerging Therapeutic Potential of SIRT6 Modulators

Sirtuin 6 (SIRT6) is an NAD⁺-dependent protein deacylase and mono-ADP-ribosyltransferase of the sirtuin family with a wide substrate specificity. In vitro and in vivo studies have indicated that SIRT6 overexpression or activation has beneficial effects for cellular processes such as DNA repair, metabolic regulation, and aging. On the other hand, SIRT6 has contrasting roles in cancer, acting either as a tumor suppressor or promoter in a context-specific manner. Given its central role in cellular homeostasis, SIRT6 has emerged as a promising target for the development of small-molecule activators and inhibitors possessing a therapeutic potential in diseases ranging from cancer to age-related disorders. Moreover, specific modulators allow the molecular details of SIRT6 activity to be scrutinized and further validate the enzyme as a pharmacological target. In this Perspective, we summarize the current knowledge about SIRT6 pharmacology and medicinal chemistry and describe the features of the activators and inhibitors identified so far.

Quercetin Inhibits Colorectal Cancer Cells Induced-Angiogenesis in Both Colorectal Cancer Cell and Endothelial Cell through Downregulation of VEGF-A/VEGFR2

Colorectal cancer (CRC) aggressiveness is caused by cancer angiogenesis which promotes the cancer growth and metastasis associated with poor prognosis and poor survival. The vascular endothelial growth factor-A (VEGF-A) and its receptor (VEGFR-2) form the major signaling pathway in cancer angiogenesis. This study aimed to investigate the anti-angiogenesis activity of quercetin in both colorectal cancer cells and endothelial cells. The tube formation of human vein endothelial cells (HUVECs) was determined by using conditioned media of HT-29 cells treated with quercetin co-cultured with HUVECs. The VEGF-A and NF-κB p65 protein expressions in the quercetin-treated HT-29 cells were determined by fluorescence assay and Western blot analysis. The VEGFR-2 protein expression in HUVECs was determined after they were co-cultured with the quercetin-treated HT-29 cells. Quercetin markedly decreased the HT-29 cell-induced angiogenesis in HUVECs. NF-κB p65 and VEGF-A protein expression were also inhibited by quercetin. Moreover, quercetin significantly inhibited VEGFR-2 expression and translocation in HUVECs after they were co-cultured with high dose quercetin-treated HT-29 cells. Taken together, quercetin had an anti-angiogenesis effect on VEGF-A inhibition related to the NF-κB signaling pathway in the HT-29 cells and reduced VEGFR-2 expression and translocation in HUVECs.

Viability of Quercetin-Induced Dental Pulp Stem Cells in Forming Living Cellular Constructs for Soft Tissue Augmentation

Autogenous gingival grafts used for root coverage or gingival augmentation procedures often result in donor site morbidity. Living cellular constructs as an exogenous alternative have been proven to be associated with lower morbidity. With the available background information, the present study aims to assess if quercetin-induced living cell constructs, derived from dental pulp stem cells, have the potential to be applied as a tool for soft tissue augmentation. The characterized dental pulp stem cells (positive for CD73, CD90, and negative for CD34, HLA-DR) were expanded in Dulbecco's Modified Eagle's medium (DMEM) supplemented with 10 mM quercetin. The handling properties of the quercetin-induced dental pulp stem cell constructs were assessed by visual, and tactile sensation. A microscopic characterization using hematoxylin and eosin staining, and qRT-PCR-based analysis for stemness-associated genes (OCT4, NANOG, SOX2, and cMyc) was also performed. Dental pulp stem cells without quercetin administration were used as the control. Dental pulp stem cell constructs induced by quercetin easily detached from the surface of the plate, whereas there was no formation in the control cells. It was also simple to transfer the induced cellular construct on the flattened surface. Microscopic characterization of the constructs showed cells embedded in a tissue matrix. Quercetin also increased the expression of stemness-related genes. The use of quercetin-induced DPSC living constructs for soft tissue augmentation could provide an alternative to autogenous soft tissue grafts to lower patient morbidity and improve esthetic outcomes.

Effectiveness of supplementation with quercetin-type flavonols for treatment of viral lower respiratory tract infections: Systematic review and meta-analysis of preclinical studies

Viral infections of the lower respiratory tract are considered a public health problem. They affect millions of people worldwide, causing thousands of deaths, and are treated with expensive medicines, such as antivirals or palliative measures. In this study, we conducted a systematic review to describe the use of quercetin‐type flavonols against lower respiratory tract viruses and discussed the preclinical impact of this approach on different signs and clinical mechanisms of infection. The systematic review was performed in PubMed/MEDLINE, Scopus, Scielo, and Biblioteca Virtual de Saúde (BVS). After the database search, 11 relevant studies were identified as eligible. The analysis of these studies showed evidence of antiviral activity of quercetin‐type flavonols with significantly reduced mortality rate (M‐H = 0.19, 95% CI: 0.05 to 0.65, p‐value = 0.008) of infected animals and a reduction in the average viral load (IV = −1.93, 95% CI: −3.54 to −0.31, p‐value = 0.02). Additionally, quercetin and its derivatives reduced the amount of proinflammatory cytokines, chemokines, reactive oxygen species, mucus production, and airway resistance in animals infected with a respiratory virus. Overall, supplementation with quercetin‐type flavonols is a promising strategy for treating viral‐induced lower respiratory tract infections.

Dietary Nutrients and Prevention of Alzheimer's disease

Alzheimer's disease is an irrevocable, progressive brain disorder that gradually destroys memory and cognitive skills. One of the extensively studied method of preventing Alzheimer's disease (AD) disease progression is by providing nutritional diet. Several reports have shown that intake of nutritional elements as huperzine A, ursolic acid, vitamins etc. can directly influence pathogenesis of AD. Surprisingly, occurrence of metabolic disorders due to unhealthy diet has been known to be a major environmental causes for AD. It has been noted that AD disease severity can be controlled by supplementing dietary supplements containing huge amounts of health-promoting ingredients. These elements promote cell health, regeneration, and the anti-aging process that specifically interrupt the pathogenic pathways in AD development. Fortunately, incorporating changes in the nutritional content is inexpensive, easy, acceptable, safe, effective, and in most cases free from major adverse events. Many nutritional phytoconstituents such as flavonoids, alkaloids, and terpenoids are still being evaluated in the hope of identifying a successful therapy for AD. This review discusses the therapeutical potential of several key nutrients that have been researched for treating AD treatment and the method of their neuroprotective intervention.

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.

Potential Therapeutic Targets of Quercetin, a Plant Flavonol, and Its Role in the Therapy of Various Types of Cancer through the Modulation of Various Cell Signaling Pathways

Polyphenolic flavonoids are considered natural, non-toxic chemopreventers, which are most commonly derived from plants, fruits, and vegetables. Most of these polyphenolics exhibit remarkable antioxidant, anti-inflammatory, and anticancer properties. Quercetin (Qu) is a chief representative of these polyphenolic compounds, which exhibits excellent antioxidant and anticancer potential, and has attracted the attention of researchers working in the area of cancer biology. Qu can regulate numerous tumor-related activities, such as oxidative stress, angiogenesis, cell cycle, tumor necrosis factor, proliferation, apoptosis, and metastasis. The anticancer properties of Qu mainly occur through the modulation of vascular endothelial growth factor (VEGF), apoptosis, phosphatidyl inositol-3-kinase (P13K)/Akt (proteinase-kinase B)/mTOR (mammalian target of rapamycin), MAPK (mitogen activated protein kinase)/ERK1/2 (extracellular signal-regulated kinase 1/2), and Wnt/β-catenin signaling pathways. The anticancer potential of Qu is documented in numerous in vivo and in vitro studies, involving several animal models and cell lines. Remarkably, this phytochemical possesses toxic activities against cancerous cells only, with limited toxic effects on normal cells. In this review, we present extensive research investigations aimed to discuss the therapeutic potential of Qu in the management of different types of cancers. The anticancer potential of Qu is specifically discussed by focusing its ability to target specific molecular signaling, such as p53, epidermal growth factor receptor (EGFR), VEGF, signal transducer and activator of transcription (STAT), PI3K/Akt, and nuclear factor kappa B (NF-κB) pathways. The anticancer potential of Qu has gained remarkable interest, but the exact mechanism of its action remains unclear. However, this natural compound has great pharmacological potential; it is now believed to be a complementary—or alternative—medicine for the prevention and treatment of different cancers.

Natural products in the reprogramming of cancer epigenetics

Owing to the technological advancements, including next generation sequencing, the significance of deregulated epigenetic mechanisms in cancer initiation, progression and treatment has become evident. The accumulating knowledge relating to the epigenetic markers viz. DNA methylation, Histone modifications and non-coding RNAs make them one of the most interesting candidates for developing anti-cancer therapies. The reversibility of deregulated epigenetic mechanisms through environmental and dietary factors opens numerous avenues in the field of chemoprevention and drug development. Recent studies have proven that plant-derived natural products encompass a great potential in targeting epigenetic signatures in cancer and numerous natural products are being explored for their possibility to be considered as "epi-drug". This review intends to highlight the major aberrant epigenetic mechanisms and summarizes the essential functions of natural products like Resveratrol, Quercetin, Genistein, EGCG, Curcumin, Sulforaphane, Apigenin, Parthenolide and Berberine in modulating these aberrations. This knowledge along with the challenges and limitations in this field has potential and wider implications in developing novel and successful therapeutic strategies. The increased focus in the area will possibly provide a better understanding for the development of dietary supplements and/or drugs either alone or in combination. The interaction of epigenetics with different hallmarks of cancer and how natural products can be utilized to target them will also be interesting in the future therapeutic approaches.

Effects of different combined regimens of cisplatin, metformin, and quercetin on nasopharyngeal carcinoma cells and subcutaneous xenografts

Cisplatin, metformin, and quercetin are all reliable anticancer drugs. However, it is unclear how effective their different combination regimens are on the growth of nasopharyngeal carcinoma cell line Sune-1 and subcutaneous xenograft in nude mice. This study evaluated the effects of single-drug, two-drug, and three-drug simultaneous or sequential combined application of these drugs on the growth of Sune-1 cells and subcutaneous xenograft tumors in nude mice. The results showed that the different combination regimens of cisplatin, metformin and quercetin all had significant inhibitory effects on the proliferation of Sune-1 cells and the growth of subcutaneous xenografts in nude mice (P < 0.01), and the inhibition rate of the three drugs simultaneous combined application was significant Higher than the two-drug combination or single-drug application (P < 0.05), the contribution level of each drug in the three-drug combination application from high to low were cisplatin > metformin > quercetin. In summary, our results indicate that the simultaneous combination of cisplatin, metformin, and quercetin may synergistically inhibit the growth of Sune-1 cells and subcutaneous xenografts in nude mice through their different anticancer mechanisms, which may be clinically refractory and provide reference for chemotherapy of patients with recurrent nasopharyngeal carcinoma.

Antioxidant, Anti-Inflammatory and Anti-Angiogenic Properties of Citrus lumia Juice

Citrus juices are a rich source of bioactive compounds with various and well-known health benefits. The aim of this study was to investigate the polyphenols and ascorbic acid content as well as to investigate the antioxidant, anti-inflammatory and anti-angiogenic properties of the juice of an ancient Mediterranean species, Citrus lumia Risso (CLJ). The antioxidant and anti-inflammatory activities were evaluated by several in vitro cell-free and cell-based assays, whereas two different in vivo models, the chick chorioallantoic membrane (CAM) and the zebrafish embryos, were used to characterize the anti-angiogenic properties. Twenty-eight polyphenols were identified by RP-LC-DAD-ESI-MS analysis (flavonoids 68.82% and phenolic acids 31.18%) with 1-caffeoyl-5-feruloylquinic acid and kaempferol 3′-rhamnoside, which represent the most abundant compounds (25.70 and 23.12%, respectively). HPLC-DAD analysis showed a high ascorbic acid content (352 mg/kg of CLJ), which contributes with polyphenols to the marked and dose-dependent antioxidant and anti-inflammatory properties observed. CLJ showed strong and dose-dependent anti-angiogenic activity as highlighted by the inhibition of blood vessel formation on CAMs and the decrease of endogenous alkaline phosphatase on zebrafish embryos. Moreover, within the concentration range tested, no dead or malformed embryos were recorded. Certainly, further studies are needed to investigate the molecular mechanisms underlying these promising biological effects, but considering the evidence of the present study, the use of CLJ as a ready-to drink safe prevention strategy for inflammatory-based diseases correlated to angiogenesis could be justified.

Quercetin-Based Nanocomposites as a Tool to Improve Dental Disease Management

The restoration and prosthetic rehabilitation of missing teeth are commonly performed using dental implants, which are extremely effective and long-lasting techniques due to their osteointegration ability with the preimplant tissues. Quercetin is a phytoestrogen-like flavonoid well known for its several positive effects on human health, mostly linked to the anti-inflammatory, antioxidant, and antibacterial activities against both Gram-positive and Gram-negative bacteria. Moreover, many studies in dentistry and the maxillofacial fields have highlighted the positive effects of quercetin on osteogenesis, acting on osteoblast activity and angiogenetic process, and promoting soft and hard tissue regeneration. This review focuses on the role of quercetin on the healing and restoration of bony defects, considering the experimental findings of its application both in vitro and in vivo as a mere compound or in association with scaffolds and dental implants having functionalized surfaces.

Molecular and Biological Functions of Quercetin as a Natural Solution for Cardiovascular Disease Prevention and Treatment

Cardiovascular disease (CVD) is a worldwide health problem with growing up rates of mortality and morbidity. Many risk factors, including high blood pressure, cigarette smoking, diabetes, obesity, and dyslipidemia are responsible for CVD. CVD can be prevented by some simple and cost-effective steps such as smoking cessation, normalizing body weight, regular physical activity, and dietary changes, including decreasing saturated fats, increasing the intake of vegetables and fruits, and reducing sugar intake. In the last decades, growing up number of studies were performed to explain the possible function of non-nutrient substances from the diet which might prevent CVD. One of these natural compounds is quercetin which is widely present in vegetables, tea, fruits and wine. Many in vitro, in vivo and clinical studies have indicated the cardioprotective functions of quercetin. They can be explained by quercetin's reducing blood pressure, antioxidant potential and some other activities. This review evaluates the experimental and clinical studies that have studied the effect of quercetin in CVD and summarizes the molecular mechanisms of action as well as clinical effects of quercetin in CVD.

Quercetin Downregulates Cyclooxygenase-2 Expression and HIF-1α/VEGF Signaling-Related Angiogenesis in a Mouse Model of Abdominal Aortic Aneurysm

Objective

Abdominal aortic aneurysm (AAA) development has been characterized by increased expression of vascular endothelial growth factor (VEGF), which contributes to angiogenesis via cyclooxygenase-2 (COX-2). Quercetin, one of the most common and well-researched flavonoids and abundant in vegetables and fruits, has beneficial effects in inhibiting angiogenesis. This study investigated the antiangiogenic effects of quercetin on experimental aneurysms.

Methods

We utilized the in vivo AAA mouse model induced by the periaortic application of CaCl₂ to examine the effectiveness of quercetin in blocking angiogenesis. Quercetin was administered at 60 mg/kg once daily on the day of the AAA induction and then continued for 6 weeks. Celecoxib, a selective COX-2 inhibitor, was used as the positive control.

Results

Our results demonstrated that quercetin significantly attenuated aneurysm growth in AAA mice and medial neovascularization. Accordingly, quercetin decreased the expression of proangiogenic mediators, including VEGF-A, intercellular adhesion molecule-1, vascular cell adhesion molecule 1, and vascular endothelial cadherin. Quercetin treatment also inhibited the expression of COX-2 and hypoxia-inducible factor 1α (HIF-1α). It was also found that quercetin-3-glucuronide, a major quercetin metabolite, downregulated the expression of COX-2, HIF-1α, VEGF-A, and matrix metalloproteinase activities in aortic vascular smooth muscle cells isolated from AAA mice.

Conclusion

Quercetin attenuates neovascularization during AAA growth, and this effect is mediated via the inhibition of COX-2, which decreases HIF-1α/VEGF signaling-related angiogenesis.

The Physiologic Activity and Mechanism of Quercetin-Like Natural Plant Flavonoids

The term "vitamin P" is an old but interesting concept. Most substances in this category belong to the family of flavonoids. "Vitamin P" has also been used to define the activity of some flavonoids, including quercetin, myricetin, and rutin. According to experimental studies, the "quercetin-like natural plant flavonoids" are beneficial to the body due to their various physiological and pharmacological activities in large doses (5 μM in vitro, 50 mg/kg in mice and 100 mg/kg in rats). The physiologically achievable concentration is 10 to 100 nM, which is quite high and hard to achieve from a normal diet. Thus, the physiologic activity and mechanism of "vitamin P" are still not clear. It should be noted that the quercetin-like natural plant flavonoids are physiological co-factors of cyclooxygenases (COXs), which are the rate-limiting key enzymes of prostaglandins. These quercetin-like natural plant flavonoids can strongly stimulate prostaglandin levels at lower doses (10 nM in vitro and in 0.1 mg/kg in vivo in rats). Although these "vitamin P" substances are not original substances in the body, their physiological functions affect the body. This review is focused on the most compelling evidence regarding the physiologic role and mechanism of quercetin-like natural plant flavonoids, which may be useful in understanding the physiological functions of "vitamin P", with the goal of focusing on the role of flavonoids in human physiological health.

The Role of Dietary Phenolic Compounds in Epigenetic Modulation Involved in Inflammatory Processes

A better understanding of the interactions between dietary phenolic compounds and the epigenetics of inflammation may impact pathological conditions and their treatment. Phenolic compounds are well-known for their antioxidant, anti-inflammatory, anti-angiogenic, and anti-cancer properties, with potential benefits in the treatment of various human diseases. Emerging studies bring evidence that nutrition may play an essential role in immune system modulation also by altering gene expression. This review discusses epigenetic mechanisms such as DNA methylation, post-translational histone modification, and non-coding microRNA activity that regulate the gene expression of molecules involved in inflammatory processes. Special attention is paid to the molecular basis of NF-κB modulation by dietary phenolic compounds. The regulation of histone acetyltransferase and histone deacetylase activity, which all influence NF-κB signaling, seems to be a crucial mechanism of the epigenetic control of inflammation by phenolic compounds. Moreover, chronic inflammatory processes are reported to be closely connected to the major stages of carcinogenesis and other non-communicable diseases. Therefore, dietary phenolic compounds-targeted epigenetics is becoming an attractive approach for disease prevention and intervention.

Therapeutic Potential of Polyphenols-Loaded Polymeric Nanoparticles in Cardiovascular System

Numerous studies document an increased production of reactive oxygen species (ROS) with a subsequent decrease in nitric oxide (NO) bioavailability in different cardiovascular diseases, including hypertension, atherosclerosis, and heart failure. Many natural polyphenols have been demonstrated to decrease ROS generation and/or to induce the endogenous antioxidant enzymatic defense system. Moreover, different polyphenolic compounds have the ability to increase the activity/expression of endothelial nitric oxide synthase (eNOS) with a subsequent enhancement of NO generation. However, as a result of low absorption and bioavailability of natural polyphenols, the beneficial effects of these substances are very limited. Recent progress in delivering polyphenols to the targeted tissues revealed new possibilities for the use of polymeric nanoparticles in increasing the efficiency and reducing the degradability of natural polyphenols. This review focuses on the effects of different natural polyphenolic substances, especially resveratrol, quercetin, curcumin, and cherry extracts, and their ability to bind to polymeric nanoparticles, and summarizes the effects of polyphenol-loaded nanoparticles, mainly in the cardiovascular system.

CANCER EPIGENETICS AND THE ROLE OF DIETARY ELEMENTS

Cancer has been a fatal disease since many decades. Over the time, it is presented in multiple ways and is a matter of consideration as accounts for the high rate of mortality. The aim of the current review was to focus on the genetics, epigenetics factors and role of medicinal plants for the cure of this inimical disease. Related articles available in English language (2002-2018) were reviewed with help of different database, including PubMed, Springer Link, Medline, Google Scholar and ScienceDirect. In order to ensure credibility and accuracy of data only those articles were considered which are published in indexed journals i.e. Web of Science and Scopus. This project was conducted at the Department of Pharmacy, Government College University, Faisalabad, Pakistan from 02-01-2019 to 28-02-2019. The genetic machinery is vibrantly involved in the interpretation of the signals and is observed to be affected by various dietary factors. A sequence of modified activities is observed with use of these dietary elements. However, the modification is reviewed through the histone acetyltransferase (HAT), histone deacetylase (HDAC) and DNA methyl transferase (DNMTs), effecting the expression of gene. These modified genes, in turn then express the signals in multiple reformed ways. Different dietary elements that are used such as polyphenol, alkaloid and flavonoids are effective against cancer. The progression of disease involves genetics and epigenetics due to amplification, translocation and mutation during gene expression. Though, many studies have been conducted elaborating the role of plants and their ingredients which play a part in inhibition of cancerous cells by blockade of cell cycle and apoptosis; more in-depth investigations are still required to identify the new drug target and novel therapeutic modalities.

Overview of biological effects of Quercetin on ovary

Over the last few decades, using natural products has been increased to treat different diseases. Today, great attention has been pointed toward the usage of natural products such as flavonoids, especially Quercetin (QUR), in the treatment of diseases. QUR as a natural antioxidant has been traditionally used to prevent or treat a variety of diseases such as cancer, cardiovascular disease, polycystic ovary syndrome (PCOS), obesity, chronic inflammation, and reproductive system dysfunction. Several studies demonstrated that QUR acts as an anti-inflammatory, anti-apoptotic, antioxidant, and anticancer agent. With this in view, in this study, we intended to describe an overview of the biological effects of QUR on the ovary. QUR improves the quality of oocytes and embryos. It affects the proliferation and apoptosis and decreases the oxidative stress in granulosa cells (GCs). Furthermore, QUR can be used as a complementary and alternative therapy in ovarian cancer and it has beneficial effects in the treatment of PCOS patients. It seems that QUR as a supplementary factor has different activities for the treatment of different disorders and it also has bidirectional activities. However, further investigations are needed for understanding the efficacy of QUR in the treatment and improvement of gynecological patients.

Understanding the Composition, Biosynthesis, Accumulation and Transport of Flavonoids in Crops for the Promotion of Crops as Healthy Sources of Flavonoids for Human Consumption

Flavonoids are a class of polyphenolic compounds that naturally occur in plants. Sub-groups of flavonoids include flavone, flavonol, flavanone, flavanonol, anthocyanidin, flavanol and isoflavone. The various modifications on flavonoid molecules further increase the diversity of flavonoids. Certain crops are famous for being enriched in specific flavonoids. For example, anthocyanins, which give rise to a purplish color, are the characteristic compounds in berries; flavanols are enriched in teas; and isoflavones are uniquely found in several legumes. It is widely accepted that the antioxidative properties of flavonoids are beneficial for human health. In this review, we summarize the classification of the different sub-groups of flavonoids based on their molecular structures. The health benefits of flavonoids are addressed from the perspective of their molecular structures. The flavonoid biosynthesis pathways are compared among different crops to highlight the mechanisms that lead to the differential accumulation of different sub-groups of flavonoids. In addition, the mechanisms and genes involved in the transport and accumulation of flavonoids in crops are discussed. We hope the understanding of flavonoid accumulation in crops will guide the proper balance in their consumption to improve human health.

Evaluation of in vivo anti-inflammatory and anti-angiogenic attributes of methanolic extract of Launaea spinosa

Launaea spinosa is used as an anti-inflammatory agent traditionally. This study was conducted to evaluate anti-inflammatory and anti-angiogenic activities of methanol extract of Launaea spinosa. Extraction was performed by maceration and the resultant green coloured extract was labelled as Ls.Me. Solubility analysis showed that Ls.Me was miscible with distilled water, normal saline, ethanol and methanol. Metal analysis following acid digestion method exhibited the presence of copper, magnesium, manganese, iron, zinc and calcium. Phytochemical analysis confirmed the presence of different classes of secondary metabolites in Ls.Me. HPLC analysis showed the presence of quercetin, gallic acid, caffeic acid, benzoic acid and sinapic acid in Ls.Me. Data of in vitro antioxidant assays showed moderate antioxidant potential of Ls.Me which was also confirmed by data of in vivo enzymes (SOD, CAT, and TSP) assays. Antimicrobial assays data showed that Ls.Me was active against S.aureus and S.epidermidis (bacterial) as well as C.albicans and A.niger (fungal) strains. Data of acute physio-pathological studies showed no abnormalities in Albino rats up to the dose of 2000 mg/kg of Ls.Me. Acute and chronic inflammatory models were used to evaluate anti-inflammatory effects of Ls.Me. Data of acute studies showed that Ls.Me has the potential to arrest inflammation produced by different mediators in a dose-dependent manner. 200 mg/kg of Ls.Me was found to produce significantly (p < 0.05) better anti-inflammatory effects than 100 mg/kg of Ls.Me. Ls.Me also significantly (p < 0.05) inhibited ear edema induced by xylene. Ls.Me showed profound anti-inflammatory responses in paw edema induced by formalin and also inhibited granuloma development in cotton pellet-induced granuloma model. Histopathological and biochemical investigations showed marked reduction in the number of inflammatory cells. TNF-α and IL-6 ELSIA kits were used to study effects of Ls.Me treatment on serum levels of TNF-α and IL-6. Data obtained showed significant (p < 0.05) reduction in TNF-α and IL-6 levels in serum of animals treated with Ls.Me. Data of in vivo angiogenesis assay showed that 200 µg/ml of Ls.Me significantly halted vasculature development indicating its potent anti-angiogenic potential. On the basis of findings of the current study, it is concluded that multiple phytochemicals present in Ls.Me act synergistically to produce anti-inflammatory and anti-angiogenic effects. Further studies are required to standardize the plant extract and explore its safety profile.

Quercetin and cancer: new insights into its therapeutic effects on ovarian cancer cells

Ovarian cancer is known as a serious malignancy that affects women's reproductive tract and can considerably threat their health. A wide range of molecular mechanisms and genetic modifications have been involved in ovarian cancer pathogenesis making it difficult to develop effective therapeutic platforms. Hence, discovery and developing new therapeutic approaches are required. Medicinal plants, as a new source of drugs, could potentially be used alone or in combination with other medicines in the treatment of various cancers such as ovarian cancer. Among various natural compounds, quercetin has shown great anti-cancer and anti-inflammatory properties. In vitro and in vivo experiments have revealed that quercetin possesses a cytotoxic impact on ovarian cancer cells. Despite obtaining good results both in vitro and in vivo, few clinical studies have assessed the anti-cancer effects of quercetin particularly in the ovarian cancer. Therefore, it seems that further clinical studies may introduce quercetin as therapeutic agent alone or in combination with other chemotherapy drugs to the clinical setting. Here, we not only summarize the anti-cancer effects of quercetin but also highlight the therapeutic effects of quercetin in the ovarian cancer.

Healthy Effects of Plant Polyphenols: Molecular Mechanisms

The increasing extension in life expectancy of human beings in developed countries is accompanied by a progressively greater rate of degenerative diseases associated with lifestyle and aging, most of which are still waiting for effective, not merely symptomatic, therapies. Accordingly, at present, the recommendations aimed at reducing the prevalence of these conditions in the population are limited to a safer lifestyle including physical/mental exercise, a reduced caloric intake, and a proper diet in a convivial environment. The claimed health benefits of the Mediterranean and Asian diets have been confirmed in many clinical trials and epidemiological surveys. These diets are characterized by several features, including low meat consumption, the intake of oils instead of fats as lipid sources, moderate amounts of red wine, and significant amounts of fresh fruit and vegetables. In particular, the latter have attracted popular and scientific attention for their content, though in reduced amounts, of a number of molecules increasingly investigated for their healthy properties. Among the latter, plant polyphenols have raised remarkable interest in the scientific community; in fact, several clinical trials have confirmed that many health benefits of the Mediterranean/Asian diets can be traced back to the presence of significant amounts of these molecules, even though, in some cases, contradictory results have been reported, which highlights the need for further investigation. In light of the results of these trials, recent research has sought to provide information on the biochemical, molecular, epigenetic, and cell biology modifications by plant polyphenols in cell, organismal, animal, and human models of cancer, metabolic, and neurodegenerative pathologies, notably Alzheimer's and Parkinson disease. The findings reported in the last decade are starting to help to decipher the complex relations between plant polyphenols and cell homeostatic systems including metabolic and redox equilibrium, proteostasis, and the inflammatory response, establishing an increasingly solid molecular basis for the healthy effects of these molecules. Taken together, the data currently available, though still incomplete, are providing a rationale for the possible use of natural polyphenols, or their molecular scaffolds, as nutraceuticals to contrast aging and to combat many associated pathologies.

Molecular mechanisms linking environmental toxicants to cancer development: Significance for protective interventions with polyphenols

Human exposure to environmental toxicants with diverse mechanisms of action is a growing concern. In addition to well-recognized carcinogens, various chemicals in environmental and occupational settings have been suggested to impact health, increasing susceptibility to cancer by inducing genetic and epigenetic changes. Accordingly, in this review, we have discussed recent insights into the pathological mechanisms of these chemicals, namely their effects on cell redox and calcium homeostasis, mitochondria and inflammatory signaling, with a focus on the possible implications for multi-stage carcinogenesis and its reversal by polyphenols. Plant-derived polyphenols, such as epigallocatechin-gallate, resveratrol, curcumin and anthocyanins reduce the incidence of cancer and can be useful nutraceuticals for alleviating the detrimental outcomes of harmful pollutants. However, development of therapies based on polyphenol administration requires further studies to validate the biological efficacy, identifying effective doses, mode of action and new delivery forms. Innovative microphysiological testing models are presented and specific proposals for future trials are given. Merging the current knowledge of multifactorial actions of specific polyphenols and chief environmental toxicants, this work aims to potentiate the delivery of phytochemical-based protective treatments to individuals at high-risk due to environmental exposure.

Influence of quercetin on the global DNA methylation pattern in pigs

The plant flavonol quercetin causes multiple health-promoting effects in human and animals.

Synergy Between Low Dose Metronomic Chemotherapy and the pH-centered Approach Against Cancer

Low dose metronomic chemotherapy (MC) is becoming a mainstream treatment for cancer in veterinary medicine. Its mechanism of action is anti-angiogenesis by lowering vascular endothelial growth factor (VEGF) and increasing trombospondin-1 (TSP1). It has also been adopted as a compassionate treatment in very advanced human cancer. However, one of the main limitations of this therapy is its short-term effectiveness: 6 to 12 months, after which resistance develops. pH-centered cancer treatment (pHT) has been proposed as a complementary therapy in cancer, but it has not been adopted or tested as a mainstream protocol, in spite of existing evidence of its advantages and benefits. Many of the factors directly or indirectly involved in MC and anti-angiogenic treatment resistance are appropriately antagonized by pHT. This led to the testing of an association between these two treatments. Preliminary evidence indicates that the association of MC and pHT has the ability to reduce anti-angiogenic treatment limitations and develop synergistic anti-cancer effects. This review will describe each of these treatments and will analyze the fundamentals of their synergy.

Ethanol Extract of Ligularia fischeri Inhibits the Lipopolysaccharide-Induced Inflammatory Response by Exerting Anti-Histone Acetyltransferase Activity to Negatively Regulate p65

Histone acetyltransferase (HAT) activity is well established to regulate inflammatory responses. In contrast, the mechanisms by which natural nutritional extracts influence epigenetic mechanisms to regulate inflammation have not yet been thoroughly investigated. Thus, in the present study, we observed that the anti-HAT activity exerted by an ethanol extract of Ligularia fischeri (ELF) inhibited inflammation. Specifically, we used a cell-free system to show that ELF attenuates HAT activity. We also demonstrated that ELF decreases lipopolysaccharide (LPS)-induced HAT mRNA and protein expression levels in Raw 264.7 cells, and thereby attenuates inflammation-induced patterns of hyperacetylation at nonhistone and histone-H4 proteins. Interestingly, we found that ELF blocked p65 translocation in LPS-stimulated Raw 264.7 cells by attenuating acetylation at lysine residue 310 of p65. Finally, we investigated whether ELF reduces the inflammatory cytokines, IL-6, IL-1β, and TNFα, using its HAT inhibitor activity. Taken together, these results suggest that ELF negatively regulates inflammatory responses by inhibiting HATs and HAT activity.

Epigenetics: The master control of endothelial cell fate in cancer

The development of new blood vessels from pre-existing vasculature is called angiogenesis. The growth of tumors depends on a network of supplying vessels that provide them with oxygen and nutrients. Pro-angiogenic factors that are secreted by tumors will trigger the sprouting of nearby existing blood vessels towards themselves and therefore researchers have developed targeted therapy towards these pro-angiogenic proteins to inhibit angiogenesis. However, certain pro-angiogenic proteins tend to bypass the inhibition. Thus, instead of targeting these expressed proteins, research towards angiogenesis inhibition had been focused on a deeper scale, epigenetic modifications. Epigenetic regulatory mechanisms are a heritable change in a sequence of stable but reversible gene function modification yet do not affect the DNA primary sequence directly. Methylation of DNA, modification of histone and silencing of micro-RNA (miRNA)-associated gene are currently considered to initiate and sustain epigenetic changes. Recent findings on the subject matter have provided an insight into the mechanism of epigenetic modifications, thus this review aims to present an update on the latest studies.

Slowing Down Ageing: The Role of Nutrients and Microbiota in Modulation of the Epigenome

The human population is getting ageing. Both ageing and age-related diseases are correlated with an increased number of senescent cells in the organism. Senescent cells do not divide but are metabolically active and influence their environment by secreting many proteins due to a phenomenon known as senescence associated secretory phenotype (SASP). Senescent cells differ from young cells by several features. They possess more damaged DNA, more impaired mitochondria and an increased level of free radicals that cause the oxidation of macromolecules. However, not only biochemical and structural changes are related to senescence. Senescent cells have an altered chromatin structure, and in consequence, altered gene expression. With age, the level of heterochromatin decreases, and less condensed chromatin is more prone to DNA damage. On the one hand, some gene promoters are easily available for the transcriptional machinery; on the other hand, some genes are more protected (locally increased level of heterochromatin). The structure of chromatin is precisely regulated by the epigenetic modification of DNA and posttranslational modification of histones. The methylation of DNA inhibits transcription, histone methylation mostly leads to a more condensed chromatin structure (with some exceptions) and acetylation plays an opposing role. The modification of both DNA and histones is regulated by factors present in the diet. This means that compounds contained in daily food can alter gene expression and protect cells from senescence, and therefore protect the organism from ageing. An opinion prevailed for some time that compounds from the diet do not act through direct regulation of the processes in the organism but through modification of the physiology of the microbiome. In this review we try to explain the role of some food compounds, which by acting on the epigenetic level might protect the organism from age-related diseases and slow down ageing. We also try to shed some light on the role of microbiome in this process.

A critical review on anti-angiogenic property of phytochemicals

Angiogenesis, a process involved in neovascularization, has been found to be associated with several metabolic diseases like cancer, retinopathy etc. Thus, currently, the focus on anti-angiogenic therapy for treatment and prevention of diseases has gained significant attention. Currently available Food and Drug Administration (FDA) approved drugs are targeting either vascular endothelial growth factor or it's receptor, but in the long term, these approaches were shown to cause several side effects and the chances of developing resistance to these drugs is also high. Therefore, identification of safe and cost-effective anti-angiogenic molecules is highly imperative. Over the past decades, dietary based natural compounds have been studied for their anti-angiogenic potential which provided avenues in improving the angiogenesis based therapy. In this review, major emphasis is given to the molecular mechanism behind anti-angiogenic effect of natural compounds from dietary sources.

Quercetin and its derivative Q2 modulate chromatin dynamics in adipogenesis and Q2 prevents obesity and metabolic disorders in rats

Recently the attention of the scientific community has focused on the ability of polyphenols to counteract adverse epigenetic regulation involved in the development of complex conditions such as obesity. The aim of this study was to investigate the epigenetic mechanisms underlying the anti-adiposity effect of Quercetin (3,3',4',5,7-pentahydroxyflavone) and of one of its derivatives, Q2 in which the OH groups have been replaced by acetyl groups. In 3 T3-L1 preadipocytes, Quercetin and Q2 treatment induce chromatin remodeling and histone modifications at the 5' regulatory region of the two main adipogenic genes, c/EBPα and PPARγ. Chromatin immunoprecipitation assays revealed a concomitant increase of histone H3 di-methylation at Lys9, a typical mark of repressed gene promoters, and a decrease of histone H3 di-methylation at Lys 4, a mark of active transcription. At the same time, both compounds inhibited histone demethylase LSD1 recruitment to the 5' region of c/EBPα and PPARγ genes, a necessary step for adipogenesis. The final effect is a significant reduction in c/EBPα and PPARγ gene expression and attenuated adipogenesis. Q2 supplementation in rats reduced the gain in body weight and in white adipose tissue, as well as the increase in adipocyte size determined by high fat diet. Moreover, Q2 improved dyslipidemia, glucose tolerance and decreased the hepatic lipid accumulation by activating the expression of beta-oxidation related genes. Our data suggest that Q2, as well as Quercetin, has the potential to revert the unfavorable epigenomic profiles associated with obesity onset. This opens the possibility to use these compounds in targeted prevention strategies against obesity.

Quercetin enhances the antitumor activity of trichostatin A through up-regulation of p300 protein expression in p53 null cancer cells

In the present study, we investigated the p53-independent mechanism by which quercetin (Q) increased apoptosis in human lung cancer H1299 cells exposed to trichostatin A (TSA), a histone deacetylase inhibitor. We also investigated the role of Q in increasing the acetylation of histones H3 and H4 and the possible mechanism. Q at 5 μM significantly increased apoptosis by 88% in H1299 cells induced by TSA at 72 h. Q also significantly increased TSA-induced death receptor 5 (DR5) mRNA and protein expression as well as caspase-10/3 activities in H1299 cells. Transfection of DR5 siRNA into H1299 cells significantly diminished the enhancing effects of Q on TSA-induced apoptosis. Furthermore, TSA in combination with Q rather than TSA alone significantly increased p300 expression. Transfection of p300 siRNA in H1299 cells significantly diminished the increase of histone H3/H4 acetylation, DR5 protein expression, caspase-10/3 activity and apoptosis induced by Q. In addition, similar effects of Q were observed when Q was combined with vorinostat, another FDA-approved histone deacetylase inhibitor. These data suggest that the up-regulation of p300 expression, which in turn increases histone acetylation and DR5 expression, plays an important role in the enhancing effect of Q on TSA/vorinostat- induced apoptosis in H1299 cells.

Dietary Compounds as Epigenetic Modulating Agents in Cancer

Epigenetic mechanisms control gene expression during normal development and their aberrant regulation may lead to human diseases including cancer. Natural phytochemicals can largely modulate mammalian epigenome through regulation of mechanisms and proteins responsible for chromatin remodeling. Phytochemicals are mainly contained in fruits, seeds, and vegetables as well as in foods supplements. These compounds act as powerful cellular antioxidants and anti-carcinogens agents. Several dietary compounds such as catechins, curcumin, genistein, quercetin and resveratrol, among others, exhibit potent anti-tumor activities through the reversion of epigenetic alterations associated to oncogenes activation and inactivation of tumor suppressor genes. In this review, we summarized the actual knowledge about the role of dietary phytochemicals in the restoration of aberrant epigenetic alterations found in cancer cells with a particular focus on DNA methylation and histone modifications. Furthermore, we discussed the mechanisms by which these natural compounds modulate gene expression at epigenetic level and described their molecular targets in diverse types of cancer. Modulation of epigenetic activities by phytochemicals will allow the discovery of novel biomarkers for cancer prevention, and highlights its potential as an alternative therapeutic approach in cancer.

A Polyphenol-Enriched Supplement Exerts Potent Epigenetic-Protective Activity in a Cell-Based Model of Brain Ischemia

Bioactive components, due in part to their epigenetic properties, are beneficial for preventing several human diseases including cerebrovascular pathologies. However, no clear demonstration supports the idea that these molecules still conserve their epigenetic effects when acting at very low concentrations reproducing the brain levels achieved after oral administration of a micronutrient supplement. In the present study, we used a cellular model of brain ischemia to investigate the neuroprotective and epigenetic activities of a commercially available micronutrient mixture (polyphenol-enriched micronutrient mixture, PMM) enriched in polyphenols ((-)-epigallocatechin-3-gallate, quercetin, resveratrol), α-lipoic acid, vitamins, amino acids and other micronutrients. Mimicking the suggested dietary supplementation, primary cultures of mouse cortical neurons were pre-treated with PMM and then subjected to oxygen glucose deprivation (OGD). Pre-treatment with PMM amounts to provide bioactive components in the medium in the nanomolar range potently prevented neuronal cell death. The protection was associated with the deacetylation of the lysin 310 (K310) on NF-κB/RelA as well as the deacetylation of H3 histones at the promoter of Bim, a pro-apoptotic target of ac-RelA(K310) in brain ischemia. Epigenetic regulators known to shape the acetylation state of ac-RelA(K310) moiety are the histone acetyl transferase CBP/p300 and the class III histone deacetylase sirtuin-1. In view of that evidence, the protection we here report unveils the efficacy of bioactive components endowed with either inhibitory activity on CBP/p300 or stimulating activity on the AMP-activated protein kinase–sirtuin 1 pathway. Our results support a potential synergistic effect of micronutrients in the PMM, suggesting that the intake of a polyphenol-based micronutrient mixture can reduce neuronal vulnerability to stressful conditions at concentrations compatible with the predicted brain levels reached by a single constituent after an oral dose of PMM.

Preventive effects of a novel herbal mixture on atopic dermatitis-like skin lesions in BALB/C mice

BACKGROUND

A combination of parts of Cornus officinalis, Rosa multiflora, Lespedeza bicolor, Platycladus orientalis, and Castanea crenata is commonly used for alleviating inflammatory skin disorders. Therefore, this study was carried out to evaluate the in vitro and in vivo preventive effects of a novel herbal formula made from the five plants (C2RLP) against atopic dermatitis in BALB/C mice.

METHODS

Mice were allocated into five groups (n = 8) including, control (Normal, petrolatum, and betamethasone treated) and treatment groups (treated with 2.5 and 5% C2RLP ointment). Atopic lesion was induced by applying 1-Chloro-2, 4-dinitrobenzene to the dorsal thoracic area of mice. Macroscopical and histological evaluations were performed to determine the effects of treatment on the progress of the skin lesions. The effects of treatment on the production and release of interleukins, interferon -ϒ, nitrite, prostaglandin E2, thymus and activation-receptor chemokine, and β-hexosaminidase were evaluated and comparisons were made between groups. In addition, the chemical compounds present in C2RLP were identified by Liquid Chromatography-Mass Spectrometry.

RESULTS

Topical application of C2RLP reduced the dermatitis score and suppressed histopathological changes in mice. Treatment significantly reduced (P < 0.05) plasma IL-4 level, the production of nitrite, prostaglandin E2, and thymus and activation-receptor chemokine production. The lipopolysaccharide-induced iNOS-mRNA expression in RAW 264.7 cells was also suppressed by high concentrations of C2RLP. In addition, C2RLP showed an inhibitory effect against DPPH free radical (IC50 = 147.5 μg/ml) and β-hexosaminidase release (IC50 = 179.5 μg/ml). Liquid Chromatography-Mass Spectrometry analysis revealed the presence of various compounds, including loganin, ellagic acid, and kaempferol 3-glucoside.

CONCLUSION

Down-regulation of T- helper 2 cellular responses and suppression of inflammatory mediators contributed to the protective effects of C2RLP from atopic dermatitis in BALB/C mice.

Melaleuca styphelioides Sm. Polyphenols Modulate Interferon Gamma/Histamine-Induced Inflammation in Human NCTC 2544 Keratinocytes

Melaleuca styphelioides, known as the prickly-leaf tea tree, contains a variety of bioactive compounds. The purposes of this study were to characterize the polyphenols extracted from Melaleuca styphelioides leaves and assess their potential antioxidant and anti-inflammatory effects. The polyphenol extracts were prepared by maceration with solvents of increasing polarity. The LC/MS-MS technique was used to identify and quantify the phenolic compounds. An assessment of the radical scavenging activity of all extracts was performed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS⁺), and ferric reducing antioxidant power (FRAP) assays. The anti-inflammatory activity was determined on interferon gamma (IFN-γ)/histamine (H)-stimulated human NCTC 2544 keratinocytes by Western blot and RT-PCR. Compared to other solvents, methanolic extract presented the highest level of phenolic contents. The most frequent phenolic compounds were quercetin, followed by gallic acid and ellagic acid. DPPH, ABTS⁺, and FRAP assays showed that methanolic extract exhibits strong concentration-dependent antioxidant activity. IFN-γ/H treatment of human NCTC 2544 keratinocytes induced the secretion of high levels of the pro-inflammatory mediator inter-cellular adhesion molecule-1 (ICAM-1), nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor kappa B (NF-κB), which were inhibited by extract. In conclusion, the extract of Melaleuca styphelioides leaves is rich in flavonoids, and presents antioxidant and anti-inflammatory proprieties. It can be proposed as a useful compound to treat inflammatory skin diseases.

pH-sensitive and biocompatible quercetin-loaded GO-PEA-HA carrier improved antitumour efficiency and specificity

A novel drug carrier was designed based on a new biomaterial, that is, graphene oxide (GO), to improve the efficiency and specificity of anticancer drug. In this study, GO was successively modified with polyetheramine (PEA) and hyaluronic acid (HA). The carrier was utilized to load an antitumor component, that is, quercetin (Que), which was derived from traditional Chinese medicine, namely the pagoda tree flower bud. This drug delivery system (DDS) exhibited pH sensibility under subacid condition and good biocompatibility even when GO concentration reached 350 μg/mL. Moreover, the antitumor efficacy was doubly improved and more long-acting compared with Que alone. Results show that the GO-based material has potential clinical applications for antitumor drug delivery.

Influence of Sourdough Fermentation on Amino Acids Composition, Phenolic Profile, and Antioxidant Properties of Sorghum Biscuits

Biscuits were produced from sorghum with and without the addition of sourdough. The influence of sourdough fermentation on the amino acids composition, phenolic profile, and antioxidant properties of the biscuits were evaluated. Phenolic compounds of the biscuits were identified and quantified using gas chromatography/mass spectrometer. The total phenol contents (TPC), total flavonoid contents (TFC), ferric reducing antioxidant properties (FRAP), 2,2'-azinobis( 3-ethylbenzothiazoline-6-sulphonic) (ABTS) scavenging ability, 1,1-diphenyl-2-picryl-hydrazy (DPPH) scavenging ability, and nitric oxide (NO) scavenging ability of the biscuits were determined. Addition of sourdough increased the total essential amino acids, total non essential amino acids, hydrophobic, and aromatic amino acids contents of the biscuits. Essential amino acid index, biological value, and predicted protein efficiency were higher in biscuits with sourdough than in biscuits without sourdough. Six phenolic compounds were identified and quantified in the biscuits. Ferulic acid was the most prominent phenolic compound, followed by chlorogenic acid. TPC, TFC, FRAP, ABTS, DPPH, and NO scavenging abilities increased significantly with the addition of sourdough. Sorghum biscuits with sourdough could be useful in dietary interventions to prevent protein-energy malnutrition. Similarly, the presence of bioactive phenolic compounds and their antioxidant efficacy suggest health benefits in the management of oxidative stress and degenerative diseases.

High Throughput Screening for Natural Host Defense Peptide-Inducing Compounds as Novel Alternatives to Antibiotics

A rise in antimicrobial resistance demands novel alternatives to antimicrobials for disease control and prevention. As an important component of innate immunity, host defense peptides (HDPs) are capable of killing a broad spectrum of pathogens and modulating a range of host immune responses. Enhancing the synthesis of endogenous HDPs has emerged as a novel host-directed antimicrobial therapeutic strategy. To facilitate the identification of natural products with a strong capacity to induce HDP synthesis, a stable macrophage cell line expressing a luciferase reporter gene driven by a 2-Kb avian β-defensin 9 (AvBD9) gene promoter was constructed through lentiviral transduction and puromycin selection. A high throughput screening assay was subsequently developed using the stable reporter cell line to screen a library of 584 natural products. A total of 21 compounds with a minimum Z-score of 2.0 were identified. Secondary screening in chicken HTC macrophages and jejunal explants further validated most compounds with a potent HDP-inducing activity in a dose-dependent manner. A follow-up oral administration of a lead natural compound, wortmannin, confirmed its capacity to enhance the AvBD9 gene expression in the duodenum of chickens. Besides AvBD9, most other chicken HDP genes were also induced by wortmannin. Additionally, butyrate was also found to synergize with wortmannin and several other newly-identified compounds in AvBD9 induction in HTC cells. Furthermore, wortmannin acted synergistically with butyrate in augmenting the antibacterial activity of chicken monocytes. Therefore, these natural HDP-inducing products may have the potential to be developed individually or in combinations as novel antibiotic alternatives for disease control and prevention in poultry and possibly other animal species including humans.