Quercetin, a dietary-derived flavonoid, possesses antiangiogenic potential

Selected Plant-Derived Polyphenols as Potential Therapeutic Agents for Peripheral Artery Disease: Molecular Mechanisms, Efficacy and Safety

Vascular diseases, such as peripheral artery disease (PAD), are associated with diabetes mellitus and a higher risk of cardiovascular disease and even death. Surgical revascularization and pharmacological treatments (mainly antiplatelet, lipid-lowering drugs, and antidiabetic agents) have some effectiveness, but the response and efficacy of therapy are overly dependent on the patient’s conditions. Thus, the demand for new cures exists. In this regard, new studies on natural polyphenols that act on key points involved in the pathogenesis of vascular diseases and, thus, on PAD are of great urgency. The purpose of this review is to take into account the mechanisms that lead to endothelium dysfunction, such as the glycoxidation process and the production of advanced glycation end-products (AGEs) that result in protein misfolding, and to suggest plant-derived polyphenols that could be useful in PAD. Thus, five polyphenols are considered, baicalein, curcumin, mangiferin, quercetin and resveratrol, reviewing the literature in PubMed. The key molecular mechanisms and preclinical and clinical studies of each selected compound are examined. Furthermore, the safety profiles of the polyphenols are outlined, together with the unwanted effects reported in humans, also by searching the WHO database (VigiBase).

A Comprehensive Analysis and Anti-Cancer Activities of Quercetin in ROS-Mediated Cancer and Cancer Stem Cells

Reactive oxygen species (ROS) induce carcinogenesis by causing genetic mutations, activating oncogenes, and increasing oxidative stress, all of which affect cell proliferation, survival, and apoptosis. When compared to normal cells, cancer cells have higher levels of ROS, and they are responsible for the maintenance of the cancer phenotype; this unique feature in cancer cells may, therefore, be exploited for targeted therapy. Quercetin (QC), a plant-derived bioflavonoid, is known for its ROS scavenging properties and was recently discovered to have various antitumor properties in a variety of solid tumors. Adaptive stress responses may be induced by persistent ROS stress, allowing cancer cells to survive with high levels of ROS while maintaining cellular viability. However, large amounts of ROS make cancer cells extremely susceptible to quercetin, one of the most available dietary flavonoids. Because of the molecular and metabolic distinctions between malignant and normal cells, targeting ROS metabolism might help overcome medication resistance and achieve therapeutic selectivity while having little or no effect on normal cells. The powerful bioactivity and modulatory role of quercetin has prompted extensive research into the chemical, which has identified a number of pathways that potentially work together to prevent cancer, alongside, QC has a great number of evidences to use as a therapeutic agent in cancer stem cells. This current study has broadly demonstrated the function-mechanistic relationship of quercetin and how it regulates ROS generation to kill cancer and cancer stem cells. Here, we have revealed the regulation and production of ROS in normal cells and cancer cells with a certain signaling mechanism. We demonstrated the specific molecular mechanisms of quercetin including MAPK/ERK1/2, p53, JAK/STAT and TRAIL, AMPKα1/ASK1/p38, RAGE/PI3K/AKT/mTOR axis, HMGB1 and NF-κB, Nrf2-induced signaling pathways and certain cell cycle arrest in cancer cell death, and how they regulate the specific cancer signaling pathways as long-searched cancer therapeutics.

Therapeutic Potential of Standardized Extract of Melilotus indicus (L.) All. and Its Phytochemicals against Skin Cancer in Animal Model: In Vitro, In Vivo, and In Silico Studies

Melilotus indicus (L.) All. is known to have anti-inflammatory and anticancer properties. The present study explored the in vivo skin carcinogenesis attenuating potential of ethanolic extract of M. indicus (L.) All. (Miet) in a 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer model. The ethanolic extract of the plant was prepared by a maceration method. HPLC analysis indicated the presence of quercetin in abundance and also various other phytoconstituents. DPPH radical scavenging assay results showed moderate antioxidant potential (IC50 = 93.55 ± 5.59 μg/mL). A topical acute skin irritation study showed the nonirritant nature of Miet. Data for the skin carcinogenic model showed marked improvement in skin architecture in Miet and its primary phytochemicals (quercetin and coumarin) treated groups. Miet 50% showed comparable effects with 5-fluorouracil. Significant (p < 0.05) anticancerous effects were seen in coumarin-quercetin combination-treated animals than in single agent (coumarin and quercetin alone)-treated animals. Chorioallantoic membrane (CAM) assay results showed the antiangiogenic potential of Miet. Treatment with Miet significantly down-regulated the serum levels of CEA (carcinoembryonic antigen) and TNF-α (Tumor necrosis factor-α). Data for the docking study indicated the binding potential of quercetin and coumarin with TNF-α, EGFR, VEGF, and BCL2 proteins. Thus, it is concluded that Miet has skin cancer attenuating potential that is proposed to be due to the synergistic actions of its bioactive molecules. Further studies to explore the effects of Miet and its bioactive molecules as an adjuvant therapy with low dose anticancer drugs are warranted, which may lead to a new area of research.

Dietary Flavonoid Intake and Chronic Sensory Conditions: A Scoping Review

Dietary flavonoids have antioxidant, anti-inflammatory, and vascular health benefits, which align with the proposed pathophysiology of age-related eye conditions and hearing problems (hearing loss and tinnitus). This scoping review is based on Arksey and O’Malley’s six-stage framework and aims to summarise current evidence on the association between the dietary flavonoid intake and chronic sensory conditions in adults, and to identify the research gaps in this area. Eligible studies were identified by searching MEDLINE, EMBASE PsycINFO via the OVID platform, and Google Scholar, as well as manually searching the reference lists of the eligible articles. The inclusion criteria included: articles with full-text access, written in the English language, and focused on chronic sensory conditions and dietary flavonoid intake in an adult population. Studies focused on flavonoid supplements were excluded. Ten studies were included in this review. The evidence suggests that the flavonoid subclass, flavonols, are protective against eye conditions, including age-related macular degeneration, cataract, and glaucoma. There is insufficient evidence to support an association with hearing loss or tinnitus. Overall, dietary flavonol intake appears to be protective against some chronic eye conditions. However, for most eye and hearing-related conditions, only one study was identified. Thus, there is a need for more recent high-quality research to be conducted to confirm any significant associations.

Antiangiogenic Phytochemicals Constituent of Diet as Promising Candidates for Chemoprevention of Cancer

Despite the extensive knowledge on cancer nature acquired over the last years, the high incidence of this disease evidences a need for new approaches that complement the clinical intervention of tumors. Interestingly, many types of cancer are closely related to dietary habits associated with the Western lifestyle, such as low fruit and vegetable intake. Recent advances around the old-conceived term of chemoprevention highlight the important role of phytochemicals as good candidates for the prevention or treatment of cancer. The potential to inhibit angiogenesis exhibited by many natural compounds constituent of plant foods makes them especially interesting for their use as chemopreventive agents. Here, we review the antitumoral potential, with a focus on the antiangiogenic effects, of phenolic and polyphenolic compounds, such as quercetin or myricetin; terpenoids, such as ursolic acid or kahweol; and anthraquinones from Aloe vera, in different in vitro and in vivo assays, and the available clinical data. Although clinical trials have failed to assess the preventive role of many of these compounds, encouraging preclinical data support the efficacy of phytochemicals constituent of diet in the prevention and treatment of cancer, but a deeper understanding of their mechanisms of action and better designed clinical trials are urgently needed.

Angioprevention of Urologic Cancers by Plant-Derived Foods

The number of cancer cases worldwide keeps growing unstoppably, despite the undeniable advances achieved by basic research and clinical practice. Urologic tumors, including some as prevalent as prostate, bladder or kidney tumors, are no exceptions to this rule. Moreover, the fact that many of these tumors are detected in early stages lengthens the duration of their treatment, with a significant increase in health care costs. In this scenario, prevention offers the most cost-effective long-term strategy for the global control of these diseases. Although specialized diets are not the only way to decrease the chances to develop cancer, epidemiological evidence support the role of certain plant-derived foods in the prevention of urologic cancer. In many cases, these plants are rich in antiangiogenic phytochemicals, which could be responsible for their protective or angiopreventive properties. Angiogenesis inhibition may contribute to slow down the progression of the tumor at very different stages and, for this reason, angiopreventive strategies could be implemented at different levels of chemoprevention, depending on the targeted population. In this review, epidemiological evidence supporting the role of certain plant-derived foods in urologic cancer prevention are presented, with particular emphasis on their content in bioactive phytochemicals that could be used in the angioprevention of cancer.

Protective Effect of Nigella sativa and Onion Extract against 5-Fluorouracil-Induced Hepatic Toxicity

Aim: The present study intended to compare the antioxidant, anti-lipid peroxidation, and anti-inflammatory potentials of Nigella Sativa (NS) and onion extract on 5-FU-induced liver damage in rats. Material and methods: 48 rats were divided into control, control group of the onion extract, control group of the NS extract, 5-FU-treated, concomitant NS-treated, and concomitant onion extract-treated. Liver sections were processed for histological analysis (light and electron microscopic examination). Liver enzymes (ALT, AST, and ALP), inflammatory markers (TNF-α and IL-1), antioxidant markers (SOD, GSH, and GSH/GSSG ratio), 4-HNE, NF-κB, and Nrf2 were evaluated. Results: The 5-FU-treated group exhibited inflammation, congested hepatic sinusoid, and steatosis. Improvement with few pathological residues was seen in the concomitant extract-treated groups. The 5-FU-treated group showed higher liver enzymes. The enzymes decreased in the concomitantly treated groups. 5-FU induced liver damage through oxidative stress, inflammation, and lipid peroxidation. Concomitantly using NS and onion extracts resulted in a reduction in oxidative stress, lipid peroxidation, and inflammation. Conclusion: NS and onion extracts attenuated 5-FU-induced liver damage via antioxidative, anti-lipid peroxidative, and anti-inflammatory mechanisms. NS's role was exceptional when compared with onion extract.

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.

Natural Products as a Promising Therapeutic Strategy to Target Cancer Stem Cells

Cancer is still a deadly disease, and its treatment desperately needs to be managed in a very sophisticated way through fast-developing novel strategies. Most of the cancer cases eventually develop into recurrencies, for which cancer stem cells (CSCs) are thought to be responsible. They are considered as a subpopulation of all cancer cells of tumor tissue with aberrant regulation of self-renewal, unbalanced proliferation, and cell death properties. Moreover, CSCs show a serious degree of resistance to chemotherapy or radiotherapy and immune surveillance as well. Therefore, new classes of drugs are rushing into the market each year, which makes the cost of therapy increase dramatically. Natural products are also becoming a new research area as a diverse chemical library to suppress CSCs. Some of the products even show promise in this regard. So, the near future could witness the introduction of natural products as a source of new chemotherapy modalities, which may result in the development of novel anticancer drugs. They could also be a reasonably-priced alternative to highly expensive current treatments. Nowadays, considering the effects of natural compounds on targeting surface markers, signaling pathways, apoptosis, and escape from immunosurveillance have been a highly intriguing area in preclinical and clinical research. In this review, we present scientific advances regarding their potential use in the inhibition of CSCs and the mechanisms by which they kill the CSCs.

Electrochemical determination of anticancer drug Bendamustine and its interaction with double strand DNA in the absence and presence of quercetin

Studies based on drug-DNA interactions, especially anticancer drug-DNA interactions, are of great importance for the method development. It is thought that single-use electrodes, which give fast, cheap and reproducible results, will make a great contribution to the chip technology for the development of individual patient analysis in the future. It is known that antioxidants reduce carcinogenesis caused by oxidative stress with their radical scavenging effects. Literature shows that quercetin (QRCT) exhibits anticancer activity by preventing oxidative cell damage as an effective radical scavenger. In this study, Bendamustine (BND), an anticancer drug, which is used in different blood cancer types, was electrochemically determined and the toxicity degree was calculated by examining the interaction of the drug with DNA in the absence and presence of QRCT, which is the first examination in the literature. Limit of detection and quantification for BND was calculated as 6.0 and 20.0 μg/mL respectively by using the equation I = 0.029 × C_BND+ 1.197, (R² = 0.997). We found that QRCT prevents the interaction between BND and DNA because of its strong interaction with DNA.

Dietary flavonoids are associated with longitudinal treatment outcomes in neovascular age-related macular degeneration

PURPOSE

To assess whether dietary intake of flavonoids are associated with longitudinal treatment outcomes of patients with neovascular age-related macular degeneration (nAMD).

METHODS

547 participants with nAMD were recruited at baseline, 494 were followed-up after receiving 12 months of anti-vascular endothelial growth factor (anti-VEGF) therapy. Baseline dietary intake of flavonoids was determined using a validated food frequency questionnaire. At follow-up, presence of intra-retinal and sub-retinal fluid (IRF and SRF), retinal pigment epithelium detachment and measurements of central macular thickness (CMT) were recorded from optical coherence tomography scans. Visual acuity (VA) was documented using LogMAR charts.

RESULTS

Participants in the first tertile of intake of the flavonol quercetin, and the flavan-3-ols epigallocatechin-3-gallate and epigallocatechin had significantly worse vision than participants in the third tertile-multivariable-adjusted least square (LS) mean VA: 14.68 vs. 19.53 (p = 0.04); 14.06 vs. 18.89 (p = 0.04); 13.86 vs. 18.86 (p = 0.03), respectively. Participants in the first compared to the third tertile of flavan-3-ol, epigallocatechin-3-gallate and epigallocatechin intake all had a twofold higher risk of IRF, multivariable-adjusted p trend of: 0.03, 0.01 and 0.02, respectively. The first vs. the third tertile of tea intake had significantly worse vision (LS mean VA: 13.49 vs. 19.04, p = 0.02), increased risk of IRF (OR 2.13, 95% CI 1.18-3.85) and greater mean CMT (279.59 μm vs. 256.52 μm, p = 0.04).

CONCLUSIONS

Higher intakes of dietary flavonoids, specifically flavonols and flavan-3-ols, could be associated with better long-term treatment outcomes in nAMD patients receiving anti-VEGF therapy. Confirmation of these associations in interventional studies could result in promising new therapeutic approaches to the treatment of nAMD.

The Use of Bio-Active Compounds of Citrus Fruits as Chemopreventive Agents and Inhibitor of Cancer Cells Viability

Common therapy of cancer, such as chemotherapy, has various side effects for the patients. In recent studies, new therapeutic approaches in cancer treatment are adjuvant therapy, along with a reduction in side effects of chemotherapy drugs. Treatment by herbal medicines may have some advantages over treatment with single purified chemicals, also in terms of side effects, the use of plants in cancer treatment is a more secure method. Citrus fruits are one of the most consumed natural products in the world due to the presence of various metabolites and bioactive compounds, such as phenols, flavonoids and, carotenoids. Bioactive compounds of citrus modulate signaling pathways and interact with signaling molecules such as apoptotic and cell cycle (P53, P21, etc.) and thus have a wide range of pharmacological activities, including anti-inflammatory, anti-cancer and oxidative stress. The findings discussed in this review strongly support their potential as anti-cancer agents. Therefore, the purpose of this review was to examine the effects of active compounds in citrus as a therapy agent in cancer treatment.

Recent Advances in Liposomal Drug Delivery System of Quercetin for Cancer Targeting: A Mechanistic Approach

Quercetin (QT, 3,3',4',5,7-pentahydroxyflavone), is a natural flavonoid with nutritional value and acts as a potential free-radical scavenger (antioxidant). QT has also been explored for its anti-cancer as well as anti-proliferative activities against numerous cancerous cells. Moreover, QT exhibits significant pro-apoptotic activity against tumor cells and is well established to control the growth of different carcinoma cells at various phases of the cell cycle. Hence, it can reduce the burden of human solid cancer and metastasis. Both these activities have been established in a diverse class of human cell lines in-vitro as well as in animal models (in-vivo). Apart from the promising therapeutic activities of QT molecule, their applications have been limited due to some major concerns, including low oral bioavailability and poor aqueous solubility. Also, rapid gastrointestinal digestion of QT seems to be a key barrier for its clinical translations for oral drug delivery in conventional dosage form. Henceforth, to overcome these drawbacks, QT is loaded with liposomal systems, which exhibit promising outcomes in the upregulation of QT by the epithelial system and also improved its targeting at the site of action. Furthermore, Liposomes based Drug Delivery Systems (LDDS) have showed significant therapeutic activity with conjugated drug moiety and exhibit safety, biocompatibility, biodegradability, and mitigated toxicity despite having certain limitations associated with physiological and biological barriers. Herein, in this review, we have focused on the mechanism related with the chemotherapeutic activity of QT and also discussed the promising activity of QT-loaded LDDS as a potent chemotherapeutic agent for cancer therapy.

Antiangiogenic Activity of Flavonoids: A Systematic Review and Meta-Analysis

Abstract: An imbalance of angiogenesis contributes to many pathologies such as cancer, arthritis and retinopathy, hence molecules that can modulate angiogenesis are of considerable therapeutic importance. Despite many reports on the promising antiangiogenic properties of naturally occurring flavonoids, no flavonoids have progressed to the clinic for this application. This systematic review and meta-analysis therefore evaluates the antiangiogenic activities of a wide range of flavonoids and is presented in two sections. The first part of the study (Systematic overview) included 402 articles identified by searching articles published before May 2020 using ScienceDirect, PubMed and Web of Science databases. From this initial search, different classes of flavonoids with antiangiogenic activities, related pathologies and use of in vitro and/or in/ex vivo angiogenesis assays were identified. In the second part (Meta-analysis), 25 studies concerning the antiangiogenic evaluation of flavonoids using the in vivo chick chorioallantoic membrane (CAM) assay were included, following a targeted search on articles published prior to June 2020. Meta-analysis of 15 out of the 25 eligible studies showed concentration dependent antiangiogenic activity of six compared subclasses of flavonoids with isoflavones, flavonols and flavones being the most active (64 to 80% reduction of blood vessels at 100 µM). Furthermore, the key structural features required for the antiangiogenic activity of flavonoids were derived from the pooled data in a structure activity relationship (SAR) study. All in all, flavonoids are promising candidates for the development of antiangiogenic agents, however further investigations are needed to determine the key structural features responsible for their activity.

Quercetin suppresses migration and invasion by targeting miR-146a/GATA6 axis in fibroblast-like synoviocytes of rheumatoid arthritis

Background: Rheumatoid arthritis (RA) is a systematic autoimmune disease which may lead to joint dysfunction and disability. Aberrant migration and invasion of fibroblast-like synoviocytes (FLSs) is one of the most predominant etiopathogenesis of RA. Quercetin is a bioflavonoid which is implicated in the development of RA, yet its role in regulating the migration and invasion of FLSs is still elusive. The aim of this study is to investigate the impact of quercetin treatment on migration and invasion of FLSs and the underlying mechanism.Methods: Capacity of migration and invasion of FLSs were assessed using transwell assay. Immunofluorescence assay was used to determine the expression of F-actin. The RNA levels of miR-146a and GATA transcription factor 6 (GATA6) were measured using quantitative real-time PCR. Western blot was used to examine the protein level of GATA6. The correlation between miR-146a and GATA6 was validated using luciferase reporter assay.Results: Transwell assay revealed that the migration and invasion of FLSs were significantly inhibited after quercetin treatment, which was also proved by decreased expression of F-actin. The RNA level of miR-146a was decreased in RA tissues and was negatively related to the expression of GATA transcription factor 6 (GATA6). Quercetin treatment elevated the RNA level of miR-146a, but suppressed the expression of GATA6 in FLSs. Further luciferase reporter assay validated that GATA6 is a downstream target of miR-146a. Besides, miR-146a inhibited the migration and invasion of FLSs, and further GATA6 over-expression abrogated the miR-146a-induced inhibition. In addition, specific anti-miR-146a inhibitor abolished quercetin-mediated suppression of migration and invasion of FLSs.Conclusion: Our study suggested that quercetin suppresses the migration and invasion of FLSs via regulating the miR-146a/GATA6 axis.

cRGDfK-Grafted Small-Size Quercetin Micelles For Enhancing Therapy Efficacy Of Active Ingredient From The Chinese Medicinal Herb

Background

As an active ingredient of Chinese herbal medicine, quercetin (QU) can significantly induce apoptosis of tumor cells and give play to other effect such as decreasing both fibroblast population and collagen in cancer cell nest. However, the antitumor efficacy of quercetin was mostly evaluated at cellular level and rarely developed in vivo by intravenous injection, which may be ascribed to its inferior physicochemical properties including water insolubility, short plasma half-time, and insufficient enrichment in the tumor tissues.

Methods

The DSPE-PEG was used to construct quercetin-loaded micelles, and the integrin ligand cRGDfK was grafted to modify the nanocarrier for enhancing its cancer-specific homing. The MALDI-TOF-MS, DLS, TEM, and UV were orderly operated to characterize guidance molecules and micelles by morphology, size distribution, Zeta potential, and drug encapsulation efficiency. In addition, the surface plasmon resonance study and real-time confocal analysis were employed to demonstrate α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake. After further pharmacodynamics studies in vitro and in vivo, we also evaluate systemic toxicity about cRGDfK-PM-QU.

Results

The cRGDfK was successfully stitched with DSPE-PEG and modified on the surface of micelles. The ligand modification enhanced the negative charges of the micelles, but it did not induce significant changes in particle size. The quercetin micelles were about 15 nm in size and negatively charged, and had spherical morphology and high drug encapsulation efficiency. In vitro, the cRGDfK-modified micelles (cRGDfK-PM) showed α_vβ₃ integrin-overexpressing B16 cells-specific binding and uptake, and cRGDfK-PM-QU (QU loaded in cRGDfK-PM) induced more significant cell apoptosis and cytotoxic effects against B16 tumor cells than counterpart micelles (PM-QU). In vivo, the cRDGfK modification enhanced enrichment in B16 tumor tissue, improved the therapeutic efficacy of the quercetin-loaded micelles against B16 tumor, and exhibited lower systemic and pulmonary toxicity compared with counterpart micelles in the mouse mode.

Conclusion

Quercetin as a natural product has triggered increasing interest in the antitumor field. In this study, cRGDfK-modified DSPE-PEG micelles significantly optimized quercetin therapeutic efficacy and pulmonary toxicity as well as lowered systemic toxicity.

Accelerated cancer aggressiveness by viral oncomodulation: New targets and newer natural treatments for cancer control and treatment

An infectious etiology for a number of cancers has been entertained for over 100 years and modern studies have confirmed that a number of viruses are linked to cancer induction. While a large number of viruses have been demonstrated in a number of types of cancers, most such findings have been dismissed in the past as opportunistic infections, especially with persistent viruses with high rates of infectivity of the world’s populations. More recent studies have clearly shown that while not definitely causing these cancers, these viruses appear capable of affecting the biology of these tumors in such a way as to make them more aggressive and more resistant to conventional treatments. The term oncomodulatory viruses has been used to describe this phenomenon. A number of recent studies have shown a growing number of ways these oncomodulatory viruses can alter the pathology of these tumors by affecting cell-signaling, cell metabolism, apoptosis mechanisms, cell-cell communication, inflammation, antitumor immunity suppression, and angiogenesis. We are also learning that much of the behavior of tumors depends on cancer stem cells and stromal cells within the tumor microenvironment, which participate in extensive, dynamic crosstalk known to affect tumor behavior. Cancer stem cells have been found to be particularly susceptible to infection by human cytomegalovirus. In a number of studies, it has been shown that while only a select number of cells are actually infected with the virus, numerous viral proteins are released into cancer and stromal cells in the microenvironment and these viral proteins are known to affect tumor behavior and aggressiveness.

Onion bulb extract reduces colitis severity in mice via modulation of colonic inflammatory pathways and the apoptotic machinery

ETHNOPHARMACOLOGICAL RELEVANCE

The use of nutraceutical-based products has increased in recent years due to their demonstrated efficacy and their good safety profile. Onion is one of the most commonly used plants in the traditional medicine for the management of various conditions including inflammatory and gastrointestinal diseases. However, little is known regarding the molecular mechanism of the anti-inflammatory effects of onion particularly in inflammatory bowel disease (IBD).

AIM OF THE STUDY

To test the anti-inflammatory effects of onion bulb extract (OBE) in an IBD mouse model and the molecular mechanisms responsible for these effects such as modulation of the expression and/or the activity profile of various pro-inflammatory molecules.

MATERIALS AND METHODS

Colitis was induced in mice by dextran sulfate sodium (DSS) daily administration for 5 days. Animals were sacrificed, colons were removed and the severity of the inflammation was determined by the gross and histological assessments. The colonic level/activity of various cytokines and chemokines were measured using proteome profiling-based assay, western blotting, and immunofluorescence techniques.

RESULTS

DSS-induced colitis was significantly reduced by the daily OBE treatment and 5-aminosalicylic acid (5-ASA, positive control), particularly at 100-200 mg/kg doses, at both the gross and histological levels. OBE was also shown to reduce colonic expression and activity of several pro-inflammatory molecules and signaling pathways, such as mitogen activated protein kinase family, mammalian target of rapamycin, cyclooxygenase-2, and tissue inhibitors of metalloproteinases. In addition, OBE reduced the expression of interferon-γ, various C-C and C-X-C chemokines, and molecules involved in the apoptotic machinery such as cytochrome c, caspase-3 and -8, B-cell lymphoma-extra-large and -2.

CONCLUSIONS

OBE showed anti-inflammatory actions in IBD mouse model, which is attributed, in part, to the modulation of the expression and the activity of important pro-inflammatory molecules and signaling pathways involved in the inflammatory response. These data suggest that OBE may be a promising lead in the therapeutic management of IBD.

Quercetin Inhibits the Proliferation of Glycolysis-Addicted HCC Cells by Reducing Hexokinase 2 and Akt-mTOR Pathway

Increased glycolysis in tumor cells is associated with increased risk of tumor progression and mortality. Therefore, disruption of glycolysis, one of the main sources of cellular energy supply, can serve as a target for suppressing tumor growth and progression. Of note, hexokinase-2 (HK2) plays vital roles in glucose metabolism. Moreover, the expression of HK2 alters the metabolic phenotype and supports the continuous growth of tumor cells, making it an attractive target for cancer therapy. Quercetin (QUE), a bioactive flavonoid, has a profound anti-tumor effect on hepatocellular carcinoma (HCC), but the precise underlying mechanism of this effect is unclear. In the present study, we reported that QUE inhibited the proliferation of HCC cells that relied on aerobic glycolysis. We further found that QUE could decrease the protein levels of HK2 and suppress the AKT/mTOR pathway in HCC cells. In addition, QUE significantly restrained the growth of HCC xenografts and decreased HK-2 expression in vivo. Taken together, we have revealed that QUE suppresses the progression of HCC by inhibiting HK2-dependentglycolysis, which may have a promising potential to be an effective treatments for HCC, especially for those patients with high HK2 expression.

Fisetin and Quercetin: Promising Flavonoids with Chemopreventive Potential

Despite advancements in healthcare facilities for diagnosis and treatment, cancer remains the leading cause of death worldwide. As prevention is always better than cure, efficient strategies are needed in order to deal with the menace of cancer. The use of phytochemicals as adjuvant chemotherapeutic agents in heterogeneous human carcinomas like breast, colon, lung, ovary, and prostate cancers has shown an upward trend during the last decade or so. Flavonoids are well-known products of plant derivatives that are reportedly documented to be therapeutically active phytochemicals against many diseases encompassing malignancies, inflammatory disorders (cardiovascular disease, neurodegenerative disorder), and oxidative stress. The current review focuses on two key flavonols, fisetin and quercetin, known for their potential pharmacological relevance. Also, efforts have been made to bring together most of the concrete studies pertaining to the bioactive potential of fisetin and quercetin, especially in the modulation of a range of cancer signaling pathways. Further emphasis has also been made to highlight the molecular action of quercetin and fisetin so that one could explore cancer initiation pathways and progression, which could be helpful in designing effective treatment strategies.

Enzymatic synthesis of novel quercetin sialyllactoside derivatives

Quercetin and its derivatives are important flavonols that show diverse biological activity, such as antioxidant, anticarcinogenic, anti-inflammatory, and antiviral activities. Adding different substituents to quercetin may change the biochemical activity and bioavailability of molecules, when compared to the aglycone. Here, we have synthesised two novel derivatives of quercetin, quercetin-3-O-β-d-glucopyranosyl, 4''-O-d-galactopyranosyl 3'''-O-α-N-acetyl neuraminic acid i.e. 3'-sialyllactosyl quercetin (3'SL-Q) and quercetin-3-O-β-d-glucopyranosyl, 4''-O-β-d-galactopyranosyl 6'''-O-α-N-acetyl neuraminic acid i.e. 6'-sialyllactosyl quercetin (6'SL-Q) with the use of glycosyltransferases and sialyltransferases enzymes. These derivatives of quercetin were characterised by high-resolution quadrupole-time-of-flight electrospray ionisation mass spectrometry (HR-QTOF-ESI/MS) and ¹H and ¹³C nuclear magnetic resonance (NMR) analyses.

Phenolic Compounds as Nutraceuticals or Functional Food Ingredients

BACKGROUND

Nowadays, the functional foods represent one the most promising, interesting and innovative areas in the food industry. Various components are being added to foods in order to render them functional.

METHODS

One example of these components are plant naturally occurring phenolic compounds, which are associated with a high antioxidant capacity and thus with benefits in relation to human health.

RESULTS

However, despite the huge number of scientific studies and patents on this topic and their natural presence in foods, namely in the ones from plant origin, there are still few marketable products enriched with these compounds. The commercialization of this type of functional products needs to go through various regulations, proving that they are safe and present the ascribed health benefits, conquering the target audience. In this review the growing interest of industry and consumers' appetence for functional foods and nutraceuticals is highlighted, focusing especially on phenolic compounds.

CONCLUSION

Although several published works show the multitude of bioactive properties of these compounds, ensuring their use as bioactive ingredients in food, they present inherent stability issues needing to be solved. However, considerable research is presently ongoing to overcome this problem, making viable the development of new products to be launched in the market.

Development of copolymeric nanoparticles of hypocrellin B: Enhanced phototoxic effect and ocular distribution

In the present work, we have developed a photosensitizer hypocrellin B (HB) and nano silver loaded PLGA-TPGS nanoparticles with improved singlet oxygen production for enhanced photodynamic effect for the efficient treatment of age related macular degeneration. Random copolymer (PLGA-TPGS) synthesized by ring opening and bulk polymerization was characterized by IR, ¹H NMR and TGA analysis. HBS-CP-NPs prepared by nanoprecipitation techniques were spherical shaped 89.6-753.6nm size particles with negative zeta potential. The average encapsulation efficiency was 84.06±11.43% and HB release from the HBS-CP-NPs was found to be biphasic with a slow release of 1.41% in the first 8h and 48.91% during 3days as measured by RP-HPLC. DSC thermograms indicate that HB was dispersed as amorphous form in HBS-CP-NPs. The ROS generation level of HBS-CP-NPs was significantly higher than that of HB/HB-CP-NPs. The production of ¹O₂ of HBS-CP-NPs has been assessed using EPR spectrometer. The ¹O₂ generating efficiency follows the order of nano silver>HB-CP-NPs>HBS-CP-NPs>pure HB drug solution. The superior phototoxic effect of HBS-CP-NPs (85.5% at 50μM) was attained at 2h irradiation in A549 cells. Significant anti angiogenic effect of HBS-CP-NPs was observed in treated CAM embryos. Following intravenous injection of HBS-CP-NPs to rabbits, the maximum amount of HB was found in retina (3h), iris (9h), aqueous humour (9h) and vitreous humour (9h).

Quercetin: A functional dietary flavonoid with potential chemo-preventive properties in colorectal cancer

Recently, an intense attention has been paid to the application of natural compounds as a novel therapeutic strategy for cancer treatment. Quercetin, a natural flavonol present in many commonly consumed food items, is widely demonstrated to exert inhibitory effects on cancer progression through various mechanisms. Since there is a strong association with diets containing abundant vegetables, fruits, and grains, and significant decline in the risk of colon cancer, accumulation studies have focused on the anticancer potential of quercetin in colorectal cancer. Cell cycle arrest, increase in apoptosis, antioxidant replication, modulation of estrogen receptors, regulation of signaling pathways, inhibition of and metastasis and angiogenesis are among various mechanisms underlying the chemo-preventive effects of quercetin in colorectal cancer. This review covers various therapeutic interactions of Quercetin as to how targets cellular involved in cancer treatment.

Clitoria ternatea flower petals: Effect on TNFR1 neutralization via downregulation of synovial matrix metalloproteases

ETHNOPHARMACOLOGICAL RELEVANCE

Clitoria ternatea Linn. (C. ternatea) is a traditionally used herb in arthritis, and its anti-arthritic activity has been attributed to polyphenols (e.g. quercetins) from its flower petal.

AIM OF THE STUDY

The present study was designed to investigate whether C. ternatea or quercetin-3ß-D-glucoside (QG) support the antibody mediated TNFα-receptor 1 (TNFR1) neutralization to ameliorate arthritis in mice.

MATERIALS AND METHODS

Development of collagen-induced arthritis (CIA) in male Swiss mice (20-22g, 3-4 weeks of age) was followed by estimation of synovial polymorphonuclear cell (PMN) accumulation (in terms of myeloperoxidase activity), synovial and systemic release of cytokines, chemokines and C-reactive protein (CRP) by enzyme-linked immunosorbent assay (ELISA), biochemical estimation of synovial free radical generation and antioxidant status, as well as immunoblot assessment of synovial TNFR1, toll-like receptor 2(TLR2), cyclooxygenase-2(COX-2) and inducible nitric oxide synthase (iNOS) expression; and zymographic analysis of synovial matrix-metalloprotease-2 (MMP-2) activity.

RESULTS

CIA was induced from day 2 post-secondary immunizations as evidenced from arthritic scores and joint swelling in parallel to increased inflammatory and oxidative stress parameters in synovial joints. Long term supplementation with extract from Clitoria ternatea flower petals CTE (50mg/kg) and QG (2.5mg/kg) upto 24 days post booster immunization augmented anti-arthritic potential of TNFR1 neutralization with anti-TNFR1 antibody (10μg per mice) in terms of reduced MPO activity, decrease in release of pro-inflammatory cytokines, chemokines, reactive oxygen species (ROS)/ reactive nitrogen species (RNS) production in parallel to significant (p<0.05) reduction in TNFR1, TLR2, iNOS, COX-2 and MMP-2 expression.

CONCLUSION

CTE and QG possess potential anti-arthritic activity which targets synovial MMP-2 in arthritic joints and TNFR1 targeting followed by CTE or QG treatment might become a combinatorial approach in future therapeutic research in treatment of arthritis.

Paclitaxel and quercetin nanoparticles co-loaded in microspheres to prolong retention time for pulmonary drug delivery

High drug resistance, poor water solubility, short half-life, and low local drug concentration are obstacles for successful delivery of chemotherapeutic drugs for lung cancer. A new method involving the use of nanoparticles (NPs) for pulmonary delivery is proposed. However, use of NPs is limited by the particle size range for pulmonary drug delivery considering that NPs cannot be deposited directly into the lungs. NPs polymerized into microspheres (polymeric microspheres, PMs) will result in suitable particle sizes and retain the advantages of nanodrugs after redispersion when applied in pulmonary delivery. We report the development of novel NPs in the form of PMs loaded with paclitaxel (PTX) and quercetin (QUE) double drugs based on the synthesis of oleic acid-conjugated chitosan (OA-CTS) for pulmonary delivery. This approach is aimed toward prolonging PTX retention time in the presence of QUE and bypassing P-glycoprotein drug efflux pumps. NPs loaded with PTX or QUE were prepared with 11% substitution degree using OA-CTS as the carrier by ionic cross-linking method, which NPs loaded with PTX or QUE were used in the preparation of PMs by spray-drying. The diameters of the PMs ranged from 1 to 5 μm which had uniform size range. Scanning electron microscopy showed that PMs were polymers formed by a large number of NPs and readily redispersed (after redispersion, size of NPs ranged between 250 and 350 nm) in water within 1 h. PMs displayed slow-release characteristics at pH 4.5 and 7.4. The in vivo pharmacokinetic and biodistribution studies suggested that PMs exhibit prolonged circulation time and a markedly high accumulation in the lung. The obtained results indicate that PMs can serve as a promising pulmonary delivery system for combined pharmacotherapy using hydrophobic anticancer drugs.

Anti-angiogenic effect of chebulagic acid involves inhibition of the VEGFR2- and GSK-3β-dependent signaling pathways

Inhibition of angiogenesis is a useful strategy to prevent cancer growth by targeting new vessels that grow to nourish actively proliferating tumor cells. Endothelial cells can use a number of different pathways to cause angiogenesis, and each step in these pathways can be targeted. The use of multi-targeted drugs is gaining much importance in this scenario. Our previous results have shown that chebulagic acid (a benzopyran tannin present in the fruits of Terminalia chebula) has anti-angiogenic properties. Thus, this study was designed to examine the molecular mechanism for the anti-angiogenic effects of chebulagic acid. Results from our investigations using molecular docking studies and human umbilical vein endothelial cells in culture suggested that chebulagic acid inhibits both GSK-3β-dependent β-catenin phosphorylation (an important mediator of VE-cadherin–β-catenin signaling) and VEGFR2 phosphorylation, which is an important step in VEGF signaling. Chebulagic acid inhibits angiogenesis by blocking both the VEGF–VEGFR2 complex and cell–cell contact dependent downstream signaling pathways.

Therapeutic effect of quercetin in collagen-induced arthritis

Quercetin, a bioactive flavonoid with anti-inflammatory, immunosuppressive, and protective properties, is a potential agent for the treatment of rheumatoid arthritis (RA). Collagen-induced arthritis (CIA) is the most commonly used animal model for studying the pathogenesis of RA. This study analysed the therapeutic role of quercetin in collagen-induced arthritis in C57BL/6 mice. The animals were allocated into five groups that were subjected to the following treatments: negative (untreated) control, positive control (arthritis-induced), arthritis+methotrexate, arthritis+quercetin, and arthritis+methotrexate+quercetin. Assessments of weight, oedema, joint damage, and cytokine production were used to determine the therapeutic effect of quercetin. This study demonstrated for the first time the anti-inflammatory and protective effects of quercetin in vivo in CIA. The results also showed that the concurrent administration of quercetin and methotrexate did not offer greater protection than the administration of a single agent. The use of quercetin as a monotherapeutic agent resulted in the lowest degree of joint inflammation and the highest protection. The reduced severity of the disease in animals treated with quercetin was associated with decreased levels of TNF-α, IL-1β, IL-17, and MCP-1. In conclusion, this study determined that quercetin, which was non-toxic, produced better results than methotrexate for the protection of joints from arthritic inflammation in mice. Quercetin may be an alternative treatment for RA because it modulates the main pathogenic pathways of RA.

Quercetin and the ocular surface: What we know and where we are going

Flavonoids are a class of plant and fungus secondary metabolites that serve functional roles in protecting against UV-induced oxidative stress, mediating auxin signaling, and promoting microbial defense. Flavonoids are extremely abundant in nature where their potent antioxidant capacity and very low toxicity makes them highly attractive as potential therapeutic agents. In terms of clinical applications, neither the Food and Drug Administration (FDA) nor the European Food Safety Authority (EFSA) has approved any health claims or drugs related to the use of flavonoids for therapeutic purposes. Quercetin is a common flavonol that has been shown to have potent antioxidant, anti-inflammatory, and anti-fibrotic activities both in vitro and in vivo in various tissues. Recently, the application of quercetin as a therapeutic has been gaining attention in the ocular surface scientific community in the study of dry eye, keratoconus, inflammation, and neovascularization of the cornea. This review will discuss the latest findings and the use of quercetin for the treatment of dystrophies of the ocular surface. Impact statement The eye represents a small portion of the human body, accounting for one decimal fraction of the anterior body surface. The cornea is an avascular, transparent tissue that acts as a primary barrier against mechanical and infectious damaging agents, protecting the internal structures of the eye. Corneal survival and function are affected by a number of factors including but not limited to injury, trauma, infection, genetics, and environment. Corneal injury, or trauma, often leads to loss of corneal transparency and even blindness. The concept of "curing" corneal opacity has been discussed in published form for over 200 years. Currently, full corneal transplant is the only treatment option. There is a strong interest in developing natural therapeutic products that come with minimum side effects. A novel antioxidant flavonoid, quercetin, has been gaining traction as a potential therapeutic to prevent the injured cornea. This review discusses the potential of this antioxidant.

Granulocyte-macrophage colony-stimulating factor increases tumor growth and angiogenesis directly by promoting endothelial cell function and indirectly by enhancing the mobilization and recruitment of proangiogenic granulocytes

Granulocyte-macrophage colony-stimulating factor has been widely used as an adjuvant therapy for cancer patients exhibiting myelosuppression induced by chemotherapy or radiotherapy. However, the effects of granulocyte-macrophage colony-stimulating factor on tumor growth, as well as its precise mechanism, are still controversial due to inconsistent evidence. This study investigated the effect of exogenous granulocyte-macrophage colony-stimulating factor on the growth of B16 melanoma, S180 sarcoma, and U14 cervical carcinoma in mice. The angiogenesis and recruitment of bone-marrow-derived cells were analyzed in tumor tissues. Interactions among granulocyte-macrophage colony-stimulating factor, bone-marrow-derived cells, and B16 tumor cells were investigated in vitro. Proangiogenic types of bone-marrow-derived cells in blood were assessed both in vivo and in vitro. The results showed that granulocyte-macrophage colony-stimulating factor markedly facilitated the growth of B16 and S180 tumors, but not U14 tumors. Granulocyte-macrophage colony-stimulating factor increased the densities of blood vessels and the number of bone-marrow-derived cells in B16 tumor tissues. The granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor cell proliferation was mediated by bone-marrow-derived cells in vitro. Meanwhile, a distinct synergistic effect on endothelial cell function between granulocyte-macrophage colony-stimulating factor and bone-marrow-derived cells was observed. After separating two types of bone-marrow-derived cells, granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor growth and angiogenesis in vivo was mediated by proangiogenic cells in granulocytes, but not monocytes, with CD11b+, vascular endothelial growth factor receptor 2, and C-X-C chemokine receptor 4 granulocytes possibly involved. These data suggest that granulocyte-macrophage colony-stimulating factor contributes to the growth and angiogenesis of certain types of tumor, and these mechanisms are probably mediated by proangiogenic cells in granulocytes. Applying granulocyte-macrophage colony-stimulating factor may attenuate the antitumor effects of chemotherapy and radiotherapy in certain types of tumor.

Antihypertensive effects of Tartary buckwheat flavonoids by improvement of vascular insulin sensitivity in spontaneously hypertensive rats

Tartary buckwheat flavonoids alleviate hypertension through attenuating vascular insulin resistance and oxidative stress.

Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?

Fruits and vegetables have long been recognized as potentially important in the prevention of cancer risk. Thus, scientific interest in nutrition and cancer has grown over time, as shown by increasing number of experimental studies about the relationship between diet and cancer development. This review attempts to provide an insight into the anti-cancer effects of Citrus fruits, with a focus on their bioactive compounds, elucidating the main cellular and molecular mechanisms through which they may protect against cancer. Scientific literature was selected for this review with the aim of collecting the relevant experimental evidence for the anti-cancer effects of Citrus fruits and their flavonoids. The findings discussed in this review strongly support their potential as anti-cancer agents, and may represent a scientific basis to develop nutraceuticals, food supplements, or complementary and alternative drugs in a context of a multi-target pharmacological strategy in the oncology.

Natural products against cancer angiogenesis

The process of angiogenesis is quite well-known nowadays. Some medicines and extracts affecting this process are already used routinely in supporting the conventional treatment of many diseases that are considered angiogenic such as cancer. However, we must be aware that the area of currently used drugs of this type is much narrower than the theoretical possibilities existing in therapeutic angiogenesis. Plant substances are a large and diverse group of compounds that are found naturally in fruits, vegetables, spices, and medicinal plants. They also have different anticancer properties. The aim of this literature review article is to present the current state of knowledge concerning the molecular targets of tumor angiogenesis and the active substances (polyphenols, alkaloids, phytohormones, carbohydrates, and terpenes) derived from natural sources, whose activity against cancer angiogenesis has been confirmed.

Quercetin-induced apoptosis of HT-29 colon cancer cells via inhibition of the Akt-CSN6-Myc signaling axis

Constitutive photomorphogenesis 9 signalosome (CSN) consists of a total of eight subunits (CSN1-CSN8) in mammalian cells. CSN6 may promote carcinogenesis by positively regulating v-myc avian myelocytomatosis viral oncogene homolog (Myc) and MDM2 proto-oncogene stability, and is regarded as a potential target for cancer therapy. Quercetin has a substantial anticancer effect on various human cancer cells. The present study investigated the effects of quercetin on HT-29 human colorectal cancer cell viability, apoptosis and cell cycle arrest using an MTT assay, flow cytometry, transmission electron microscopy and western blotting. It was determined that quercetin inhibited HT-29 cell viability in a dose-dependent manner. Cell shrinkage, chromatin condensation and nuclear collapse were observed in the 50, 100 and 200 µM quercetin groups. The exposure of HT-29 cells to quercetin led to significant cell cycle arrest in the S-phase. Western blot analysis revealed that quercetin reduced the protein expression levels of phosphorylated-Akt and increased CSN6 protein degradation; therefore, affecting the expression levels of Myc, p53, B-cell lymphoma 2 (Bcl-2) and Bcl-2 associated X protein. The overexpression of CSN6 reduced the effect of quercetin treatment on HT-29 cells, suggesting that quercetin-induced apoptosis may involve the Akt-CSN6-Myc signaling axis in HT-29 cells.

Molecular mechanisms of action of quercetin in cancer: recent advances

In the last few decades, the scientific community has discovered an immense potential of natural compounds in the treatment of dreadful diseases such as cancer. Besides the availability of a variety of natural bioactive molecules, efficacious cancer therapy still needs to be developed. So, to design an efficacious cancer treatment strategy, it is essential to understand the interactions of natural molecules with their respective cellular targets. Quercetin (Quer) is a naturally occurring flavonol present in many commonly consumed food items. It governs numerous intracellular targets, including the proteins involved in apoptosis, cell cycle, detoxification, antioxidant replication, and angiogenesis. The weight of available synergistic studies vigorously fortifies the utilization of Quer as a chemoprevention drug. This extensive review covers various therapeutic interactions of Quer with their recognized cellular targets involved in cancer treatment.

Polyphenol-based nutraceuticals for the control of angiogenesis: Analysis of the critical issues for human use

Angiogenesis, the formation of new blood-vessel, is crucial in the pathogenesis of several diseases, and thus represents a druggable target for the prevention and treatment of different disorders. It is nowadays well kwon how diet can control cancer development and progression, and how the use of certain diet components can prevent cancer development. Several studies, also from our lab, now indicate that natural plant products including nutraceuticals modulate tumor angiogenesis. In this review, it is reported how phytochemicals, comprising hydroxytyrosol, resveratrol, genistein, curcumin, and the green tea component epigallocatechin-3-gallate among the others, negatively regulate angiogenesis. A single plant-derived compound may affect both endothelial and tumor cells, with the common denominator of anti-inflammatory and radical scavenger activities. Beside these positive features, documented in cellular and animal models, a series of critical issues should be considered from a pharmacological point of view as: what is the best source of bioactive compounds: food and beverages, extracted phytocomplexes, isolated nutraceuticals or synthetic analogues? How is the bioavailability of the compounds of interest in relation to the above source? Is there any biological activity by circulating metabolic derivatives? What is the best formulation, administration route and posology? How safe are in humans? How strong and reliable are the clinical trials designed for their use alone or in combination with conventional chemotherapy? After a dissertation of these critical points, the conclusion can be drawn that novel and effective strategies should be optimized to improve their bioavailability and efficacy, considering their exploitation as chemopreventive and/or curative approaches.

Novel self-assembled pH-responsive biomimetic nanocarriers for drug delivery

Novel pH-responsive biodegradable biomimetic nanocarriers were prepared by the self-assembly of N-acetyl-l-histidine-phosphorylcholine-chitosan conjugate (NAcHis-PCCs), which was synthesized via Atherton-Todd reaction to couple biomembrane-like phosphorylcholine (PC) groups, and N,N'-carbonyldiimidazole (CDI) coupling reaction to link pH-responsive N-acetyl-l-histidine (NAcHis) moieties to chitosan. In vitro biological assay revealed that NAcHis-PCCs nanoparticles had excellent biocompatibility to avoid adverse biological response mainly owing to their biomimetic PC shell, and DLS results confirmed their pH-responsive behavior in acidic aqueous solution (pH≤6.0). Quercetin (QUE), an anti-inflammatory, antioxidant and potential anti-tumor hydrophobic drug, was effectively loaded in NAcHis-PCCs nanocarriers and showed a pH-triggered release behavior with the enhanced QUE release at acidic pH5.5 compared to neutral pH7.4. The results indicated that pH-responsive biomimetic NAcHis-PCCs nanocarriers might have great potential for site-specific delivery to pathological acidic microenvironment avoiding unfavorable biological response.

Biologically Active Compounds from Hops and Prospects for Their Use

Although female cones of the hop plant (Humulus lupulus) are known primarily as raw material supplying characteristic bitterness and aroma to beer, their equally significant health-promoting effects have been known to mankind for several thousand years and hop is a plant traditionally utilized in folk medicine. This paper summarizes the scientific knowledge on the effects of all 3 major groups of secondary metabolites of hops; polyphenols, essential oils, and resins. Because of their chemical diversity, it is no coincidence that these compounds exhibit a wide range of pharmacologically important properties. In addition to antioxidant, anti-inflammatory, and anticancer-related properties, particular attention is being paid to prenylflavonoids that occur almost exclusively in hops and are considered to be some of the most active phytoestrogens known. Hop oils and resins are well known for their sedative and other neuropharmacological properties, but in addition, these compounds exhibit antibacterial and antifungal effects. Recently, alpha bitter acids have been shown to block the development of a number of complex lifestyle diseases that are referred to by the collective name "metabolic syndrome." Information presented in this review confirms the significant potential for the use of hops in the pharmaceutical industry and provides an understanding of beer as a natural drink that, although moderately consumed, may become a source of many health-promoting compounds.

Tumor-targeted docetaxel-loaded hyaluronic acid-quercetin polymeric micelles with p-gp inhibitory property for hepatic cancer therapy

Herein, a novel targeted drug delivery nanosystem based on hyaluronic acid (HA) and quercetin (QU) was designed to improve the in vivo therapeutic efficacy of DTX on HC through HA-CD44 mediated targeting and QU-based p-gp efflux inhibition.

Frequency Modulated Translocational Oscillations of Nrf2 Mediate the Antioxidant Response Element Cytoprotective Transcriptional Response

AIMS

Stress responsive signaling coordinated by nuclear factor erythroid 2-related factor 2 (Nrf2) provides an adaptive response for protection of cells against toxic insults, oxidative stress and metabolic dysfunction. Nrf2 regulates a battery of protective genes by binding to regulatory antioxidant response elements (AREs). The aim of this study was to examine how Nrf2 signals cell stress status and regulates transcription to maintain homeostasis.

RESULTS

In live cell microscopy we observed that Nrf2 undergoes autonomous translocational frequency-modulated oscillations between cytoplasm and nucleus. Oscillations occurred in quiescence and when cells were stimulated at physiological levels of activators, they decrease in period and amplitude and then evoke a cytoprotective transcriptional response. We propose a mechanism whereby oscillations are produced by negative feedback involving successive de-phosphorylation and phosphorylation steps. Nrf2 was inactivated in the nucleus and reactivated on return to the cytoplasm. Increased frequency of Nrf2 on return to the cytoplasm with increased reactivation or refresh-rate under stress conditions activated the transcriptional response mediating cytoprotective effects. The serine/threonine-protein phosphatase PGAM5, member of the Nrf2 interactome, was a key regulatory component.

INNOVATION

We found that Nrf2 is activated in cells without change in total cellular Nrf2 protein concentration. Regulation of ARE-linked protective gene transcription occurs rather through translocational oscillations of Nrf2. We discovered cytoplasmic refresh rate of Nrf2 is important in maintaining and regulating the transcriptional response and links stress challenge to increased cytoplasmic surveillance. We found silencing and inhibition of PGAM5 provides potent activation of Nrf2.

CONCLUSION

Frequency modulated translocational oscillations of Nrf2 mediate the ARE-linked cytoprotective transcriptional response.

Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy

The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.

Qualitative and nutraceutical aspects of lemon fruits grown on the mountainsides of the Mount Etna: A first step for a protected designation of origin or protected geographical indication application of the brand name 'Limone dell'Etna'

The cultivation of lemon (Citrus limon (L.) Burm f.) has occurred for centuries at the mountainsides of the Mount Etna the largest active volcano in Europe (Sicily, Italy). The peculiar geographical, soil and climatic conditions that characterize this area have recently prompted citrus growers to launch the brand name 'Limone dell'Etna' for the lemon fruits produced in that area. The present research focused on evaluating the quality and nutraceutical properties of the 'Limone dell'Etna' fruit juice ('Primofiore', 'Bianchetto', and 'Verdello' blooming) to enhance the value of a product that, due to its peculiar qualities, could be awarded with one of the European certified labels protecting the lemon geographical origin. Qualitative parameters, health-promoting components (such as ascorbic acid, flavonoids, and hydroxycinnamic acids) and the in-vitro total antioxidant capacity (ORAC, FCR) of fruit juice of two different varieties ('Femminello zagara bianca' and 'Monachello') were determined at fruit maturity. The results showed that the Bianchetto and Verdello lemon fruit exhibited higher levels of ascorbic acid than those recorded for the Primofiore production. The amount of flavonoids in Verdello fruits of both cultivars was the highest, as was reflected in the highest antioxidant activity. Thus, the 'Limone dell'Etna' production, with particular reference to the Verdello fruit, must be considered as a new, valuable and original source of natural antioxidants to be valorized and even exploited in the processing industry.