3-methylquercetin and Inflammation

Diabetes mellitus, especially type 2 (T2DM), is a major public health problem globally. DM is characterized by high levels of glycemia and insulinemia due to impaired insulin secretion and insulin sensitivity of the cells, known as insulin resistance. T2DM causes multiple and severe complications such as nephropathy, neuropathy, and retinopathy causing cell oxidative damages in different internal tissues, particularly the pancreas, heart, adipose tissue, liver, and kidneys. Plant extracts and their bioactive phytochemicals are gaining interest as new therapeutic and preventive alternatives for T2DM and its associated complications. In this regard, isorhamnetin, a plant flavonoid, has long been studied for its potential anti-diabetic effects. This review describes its impact on reducing diabetes-related disorders by decreasing glucose levels, ameliorating the oxidative status, alleviating inflammation, and modulating lipid metabolism and adipocyte differentiation by regulating involved signaling pathways reported in the in vitro and in vivo studies. Additionally, we include a post hoc whole-genome transcriptome analysis of biological activities of isorhamnetin using a stem cell-based tool.

Topics: Animals; Diabetes Mellitus, Type 2; Gene Expression Profiling; Humans; Inflammation; Lipid Metabolism; Oxidative Stress; Quercetin

Inflammation comprises the reaction of the body to injury, in which a series of changes of the terminal vascular bed, blood, and connective tissue tends to eliminate the injurious agent and to repair the damaged tissue. It is a complex process, which involves the release of diverse regulatory mediators. The current anti-inflammatory agents are challenged by multiple side effects and thus, new effective therapies are highly needed. The aim of this review is to summarize the described microsomal prostaglandin E synthase-1 (mPGES-1) inhibitors or transcriptional suppressors from medicinal plants, which could be an ideal approach in the management of inflammatory disorders, but need further clinical trials in order to be ultimately validated.

Topics: Animals; Anti-Inflammatory Agents; Biological Products; Drug Discovery; Enzyme Inhibitors; Humans; Inflammation; Plants, Medicinal; Prostaglandin-E Synthases

Epidemiologic evidence supports that dietary quercetin reduces cardiovascular disease (CVD) risk, but its oral bioavailability is paradoxically low. The aim of this study was to determine whether dietary fat would improve quercetin bioavailability in adults at high risk for CVD and to assess lipid-mediated micellarization of quercetin in vitro.. In a randomized, cross-over study, overweight/obese men and postmenopausal women (n = 4 M/5 F; 55.9 ± 2.1 years; 30.8 ± 1.4 kg/m(2) ) ingested 1095 mg of quercetin aglycone with a standardized breakfast that was fat-free (<0.5 g), low-fat (4.0 g), or high-fat (15.4 g). Plasma was obtained at timed intervals for 24 h to measure quercetin and its methylated metabolites isorhamnetin and tamarixetin. Compared to the fat-free trial, plasma quercetin maximum concentration (Cmax ), and area under curve (AUC0-24 h ) increased (p < 0.05) by 45 and 32%, respectively, during the high-fat trial. During the high-fat trial, isorhamnetin Cmax and AUC0-24 h also increased by 40 and 19%, respectively, whereas Cmax and AUC0-24 h of tamarixetin increased by 46 and 43%, respectively. Dietary fat dose-dependently increased micellarization efficiency of quercetin aglycone in vitro.. Dietary fat improves quercetin bioavailability by increasing its absorption, likely by enhancing its micellarization at the small intestine.

Topics: Area Under Curve; Biological Availability; Biomarkers; Body Mass Index; Chromatography, High Pressure Liquid; Cross-Over Studies; Dietary Fats; Disaccharides; Female; Humans; Inflammation; Linear Models; Male; Middle Aged; Overweight; Oxidative Stress; Quercetin

Our aim was to investigate the effects of an oral supplementation of quercetin at 3 different doses on plasma concentrations of quercetin, parameters of oxidant/antioxidant status, inflammation, and metabolism. To this end, 35 healthy volunteers were randomly assigned to take 50, 100, or 150 mg/d (group Q50-Q150) quercetin for 2 wk. Fasting blood samples were collected at the beginning and end of the supplementation period. Compared with baseline, quercetin supplementation significantly increased plasma concentrations of quercetin by 178% (Q50), 359% (Q100), and 570% (Q150; P < 0.01 for all). High interindividual variation was found for plasma quercetin concentrations (36-57%). Quercetin did not affect concentrations of serum uric acid or plasma alpha- and gamma-tocopherols, oxidized LDL, and tumor necrosis factor-alpha, or plasma antioxidative capacity as assessed by the ferric-reducing antioxidant potential and oxygen radical absorbance capacity assays. In addition, serum lipids and lipoproteins, body composition, and resting energy expenditure did not significantly change during quercetin supplementation. Pharmacokinetics of quercetin were investigated in a subgroup of 15 volunteers. The areas under the plasma concentration-time curves ranged from 76.1 mumol.min.L(-1) to 305.8 mumol.min.L(-1) (50- and 150-mg dosages, respectively). Median maximum plasma concentrations of quercetin (431 nmol/L) were observed 360 min after intake of 150 mg quercetin. In conclusion, daily supplementation of healthy humans with graded concentrations of quercetin for 2 wk dose-dependently increased plasma quercetin concentrations but did not affect antioxidant status, oxidized LDL, inflammation, or metabolism.

Topics: Administration, Oral; Adult; Antioxidants; Dietary Supplements; Disaccharides; Dose-Response Relationship, Drug; Double-Blind Method; Energy Metabolism; Female; Flavonols; Humans; Inflammation; Male; Nutritional Physiological Phenomena; Oxidative Stress; Quercetin

Background: Isorhamnetin is a flavonoid that is found in medical plants. Several studies showed that isorhamnetin has anti-inflammatory and anti-obesity effects. This study aims to investigate the anti-diabetic effects of isorhamnetin in a high-fat diet and Streptozotocin-(HFD/STZ)-induced mice model of type 2 diabetes. Materials and Methods: Mice were fed with HFD followed by two consecutive low doses of STZ (40 mg/kg). HFD/STZ diabetic mice were treated orally with isorhamnetin (10 mg/kg) or (200 mg/kg) metformin for 10 days before sacrificing the mice and collecting plasma and soleus muscle for further analysis. Results: Isorhamnetin reduced the elevated levels of serum glucose compared to the vehicle control group (p < 0.001). Isorhamnetin abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control mice (p < 0.001). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in diabetic mice treated with isorhamnetin compared to the vehicle controls. Fasting glucose level was significantly lower in diabetic mice treated with isorhamnetin during the intraperitoneal glucose tolerance test (IPGTT) (p < 0.001). The skeletal muscle protein contents of GLUT4 and p-AMPK-α were upregulated following treatment with isorhamnetin (p > 0.01). LDL, triglyceride, and cholesterol were reduced in diabetic mice treated with isorhamnetin compared to vehicle control (p < 0.001). Isorhamnetin reduced MDA, and IL-6 levels (p < 0.001), increased GSH levels (p < 0.001), and reduced GSSG levels (p < 0.05) in diabetic mice compared to vehicle control. Conclusions: Isorhamnetin ameliorates insulin resistance, oxidative stress, and inflammation. Isorhamnetin could represent a promising therapeutic agent to treat T2D.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Glucose; Hypoglycemic Agents; Inflammation; Insulin Resistance; Mice; Oxidative Stress; Streptozocin

Isorhamnetin has distinct anti-inflammatory activity and inhibits cell proliferation and migration. These effects are also involved in the pathogenesis of asthma. However, the effect of isorhamnetin on bronchial epithelial cells in patients with asthma has not been examined. Cells of human bronchial epithelial cell line BEAS-2B were cultured with isorhamnetin and tumor necrosis factor (TNF)-α. The effects of isorhamnetin on BEAS-2B cell viability were assessed using CCK8 assay. The EdU (5-ethynyl-2'-deoxyuridine) cell proliferation assay was performed to assess cell proliferation. BEAS-2B cell migration was measured using Transwell and wound healing assays. Real-time PCR and enzyme-linked immunosorbent assay were conducted to measure the expression of pro-inflammatory cytokines. Protein expression levels were determined by western blotting. Immunofluorescence was used to detect nuclear translocation of nuclear factor kappa B (NF-κB). We found that isorhamnetin at 20 and 40 μM reduced the proliferation of BEAS-2B cells induced by TNF-α. Isorhamnetin significantly decreased the expression of interleukin (IL)-1β, IL-6, IL-8, and C-X-C motif chemokine ligand 10 in BEAS-2B cells induced by TNF-α. Additionally, 10 μM isorhamnetin effectively reduced cell migration induced by TNF-α. Treatment with isorhamnetin inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) and NF-κB pathways induced by TNF-α. In summary, isorhamnetin inhibited the inflammation, proliferation, and migration of BEAS-2B cells by regulating the MAPK and NF-κB signaling pathways and is a drug candidate for asthma.

Topics: Bronchi; Cell Line; Cell Movement; Cell Proliferation; Cytokines; Epithelial Cells; Humans; Inflammation; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Quercetin; Signal Transduction; Tumor Necrosis Factor-alpha

Streptococcus suis (S. suis) is one of the most common swine pathogens in the swine industry and leads to great harm to the normal progress of the swine industry. S. suis can also infect humans and cause a variety of fatal diseases, such as meningitis and streptococcal toxic shock syndrome, that pose a major threat to the safety of life and health of both humans and animals. In this paper, we found that isorhamnetin, a natural flavonoid compound without activity against S. suis, could significantly reduce the S. suis-stimulated production of the inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α) and down-regulate the inflammatory response by inhibiting the activation of p38 and ERK in tissues infected with S. suis, thereby exerting protection against S. suis infection. The above findings suggest that isorhamnetin is a potential lead compound for the treatment of S. suis infections, thus laying a preliminary theoretical foundation for the further development of isorhamnetin as a candidate drug.

Topics: Animals; Anti-Bacterial Agents; Blotting, Western; Cell Line; Inflammation; Kinetics; Macrophages; MAP Kinase Signaling System; Mice; p38 Mitogen-Activated Protein Kinases; Quercetin; Streptococcus suis

Topics: Animals; Escherichia coli; Female; Inflammation; Mice; Mice, Inbred BALB C; Quercetin; Sepsis; Surface Plasmon Resonance; Toll-Like Receptor 4

Isorhamnetin, a derivative of quercetin, exerts antioxidant and anti-inflammatory effects in different diseases, and we examined its protective effects against diabetes-related changes in the brain.. A single dose of a freshly prepared solution of streptozotocin (STZ) (60 mg/kg body weight) was intraperitoneally injected to establish STZ-induced diabetic model in male Wistar rats. The animals were randomly divided into four groups: control, control + isorhamnetin, diabetic, diabetic + isorhamnetin. Isorhamnetin at a dose of 10 mg/kg body weight was intraperitoneally administrated once a day for 12 weeks. Formalin and tail immersion tests were performed to evaluate the severity of pain. Astrogliosis markers such as GFAP and APO-E4, DNA fragments, MDA level, and TNFα expressions were evaluated using ELISA assay. Neuronal density in the hippocampus region was evaluated using Nissl staining. The method of Ellman and fluorescent probe 2, 7-dichlorofluorescein diacetate (DCFH-DA) was used to measure brain acetyl-cholinesterase activity and detect reactive nitrogen and oxygen species (RNS and ROS), respectively.. Isorhamnetin reduced pain, blood glucose levels, and increased body weight significantly compared to control. Moreover, isorhamnetin inhibited astroglial activation, acetyl-cholinesterase activity, oxidative stress, apoptosis, and inflammation.. These findings suggested that isorhamnetin has potential effects as neuroprotective agents against diabetes-related changes in the brain.

Topics: Animals; Apoptosis; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; DNA Fragmentation; Inflammation; Male; Malondialdehyde; Neurons; Neuroprotective Agents; Oxidative Stress; Pain; Pain Measurement; Quercetin; Rats; Rats, Wistar; Reactive Nitrogen Species; Reactive Oxygen Species

Periodontitis is a highly prevalent infective and inflammatory disease with an adverse impact on systemic health. Isorhamnetin, a flavonoid mainly isolated from Hippophae fhamnoides L. fruit, has been reported to have anti-inflammatory effect. This study aimed to investigate the anti-inflammatory effects and mechanism of isorhamnetin on lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (HGFs). The production of inflammatory mediators and the expression of proteins were measured by ELISA and western blot analysis. The results demonstrated that isorhamnetin attenuated LPS-induced release of PGE

Topics: Anti-Inflammatory Agents; Cell Survival; Dinoprostone; Fibroblasts; Gingiva; Heme Oxygenase-1; Humans; Inflammation; Interleukin-6; Interleukin-8; Lipopolysaccharides; NF-E2-Related Factor 2; NF-kappa B; Periodontitis; Quercetin; Signal Transduction

Neuroinflammation is a key contributor to neuronal damage in neurodegenerative diseases. In our previous work on natural effective neuroinflammatory inhibitors, Alhagi sparsifolia Shap. (Leguminosae), a folk medicine widely distributed in Xinjiang, attracted our attention because of its significant anti-neuroinflammatory effect. Therefore, further investigation of the bioactive material basis was carried out. As a result, 33 major components were characterized and identified by chromatographic and spectral methods, respectively. Furthermore, the anti-neuroinflammatory effects of the extract and purified constituents were evaluated in LPS-induced N9 cells in vitro. The results displayed that compounds 1, 2, 3, 5, 6, 8, 11, 15, 16, 17, 22, 23, 25, 26, 28, 30, 33 could exhibit significant inhibitory activities without obvious cytotoxicities at their effective concentrations. Especially, isorhamnetin (1) (IC

Topics: Cell Line; Fabaceae; Humans; Inflammation; Lipopolysaccharides; Microglia; Neuroprotective Agents; Plant Extracts

Diets rich in fruits and vegetables (FV), which contain (poly)phenols, protect against age-related inflammation and chronic diseases. T-lymphocytes contribute to systemic cytokine production and are modulated by FV intake. Little is known about the relative potency of different (poly)phenols in modulating cytokine release by lymphocytes. We compared thirty-one (poly)phenols and six (poly)phenol mixtures for effects on pro-inflammatory cytokine release by Jurkat T-lymphocytes. Test compounds were incubated with Jurkat cells for 48 h at 1 and 30 µm, with or without phorbol ester treatment at 24 h to induce cytokine release. Three test compounds that reduced cytokine release were further incubated with primary lymphocytes at 0·2 and 1 µm for 24 h, with lipopolysaccharide added at 5 h. Cytokine release was measured, and generation of H2O2 by test compounds was determined to assess any potential correlations with cytokine release. A number of (poly)phenols significantly altered cytokine release from Jurkat cells (P<0·05), but H2O2 generation did not correlate with cytokine release. Resveratrol, isorhamnetin, curcumin, vanillic acid and specific (poly)phenol mixtures reduced pro-inflammatory cytokine release from T-lymphocytes, and there was evidence for interaction between (poly)phenols to further modulate cytokine release. The release of interferon-γ induced protein 10 by primary lymphocytes was significantly reduced following treatment with 1 µm isorhamnetin (P<0·05). These results suggest that (poly)phenols derived from onions, turmeric, red grapes, green tea and açai berries may help reduce the release of pro-inflammatory mediators in people at risk of chronic inflammation.

Topics: Cell Survival; Chronic Disease; Curcuma; Curcumin; Cytokines; Euterpe; Female; Humans; Hydrogen Peroxide; Inflammation; Jurkat Cells; Lipopolysaccharides; Lymphocytes; Middle Aged; Onions; Polyphenols; Quercetin; Resveratrol; Stilbenes; Tea; Vanillic Acid; Vitis

Isorhamnetin, a flavonoid mainly found in Hippophae fhamnoides L. fruit, has been known for its antioxidant activity and its ability to regulate immune response. In this study, we investigated whether isorhamnetin exerts potent antiinflammatory effects in RAW264.7 cell and mouse model stimulated by LPS. The cytokine (TNF-α, IL-1β, and IL-6) levels were determined. In the mouse model of acute lung injury, the phosphorylation of NF-κB proteins was analyzed and inhibitor of NF-κB signaling (PDTC) was used on mice. Our results showed that isorhamnetin markedly decreased TNF-α, IL-1β, and IL-6 concentrations and suppressed the activation of NF-κB signaling. Meanwhile, isorhamnetin reduced the amount of inflammatory cells, the lung wet-to-dry weight ratio, protein leakage, and myeloperoxidase activity. Interference with specific inhibitor revealed that isorhamnetin-mediated suppression of cytokines and protein was via NF-κB signaling. So, it suggests that isorhamnetin might be a potential therapeutic agent for preventing inflammatory diseases.

Topics: Acute Lung Injury; Animals; Antioxidants; Cytokines; Disease Models, Animal; Down-Regulation; Inflammation; Lipopolysaccharides; Mice; NF-kappa B; Quercetin; RAW 264.7 Cells; Signal Transduction

Little is known about the role of isorhamnetin on endothelial cell apoptosis and inflammation when insulted by TNF-α injury. In our study, HUVECs were treated with TNF-α for 6 hours. HUVECs apoptosis were detected using flow cytometry. The expressions of ICAM-1, VCAM-1, E-selectin, NF-κB, AP-1 and eNOS were determined with western blotting or flow cytometry. The results showed TNF-α increased of apoptosis and the expression of ICAM-1, VCAM-1 and E-selectin in HUVECs, accompanied by significant augmentation of NF-κB and AP-1 expression. Pretreatment with isorhamnetin significantly reduced apoptosis in TNF-α-treated HUVECs. Moreover, isorhamnetin significantly attenuated TNF-α-induced upregulation of ICAM-1, VCAM-1, AP-1, E-selectin and NF-κB expression. Meanwhile, isorhamnetin also increased the expression of eNOS. So, isorhamnetin could suppress TNF-α-induced apoptosis and inflammation by blocking NF-κB and AP-1 signaling in HUVECs, which might be one of the underlying mechanisms for treatment of coronary heart disease.

Topics: Anti-Inflammatory Agents; Apoptosis; Cells, Cultured; Cytoprotection; E-Selectin; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Intercellular Adhesion Molecule-1; NF-kappa B; Nitric Oxide Synthase Type III; Quercetin; Signal Transduction; Time Factors; Transcription Factor AP-1; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Previously, we reported that isorhamnentin, a 3'-O-methylated metabolite of quercetin, reduced inducible nitric oxide synthase (iNOS) expression and NO production. The present study further investigated the underlying mechanism of anti-inflammatory and antioxidant effects of isorhamnentin. Administration of isorhamnetin decreased the number of cyclooxygenase-2 (COX-2) positive cells in rats with carrageenan-induced paw edema. Isorhamnetin also suppressed lipopolysaccharide (LPS)-induced expression of COX-2 in cells. It is well known that LPS-induced reactive oxygen species (ROS) production leads to COX-2 induction. Isorhamnetin decreased LPS-induced ROS production and apoptosis. In addition, the basal expression of heme oxygenase-1 (HO-1) was increased by isorhamnetin treatment in agreement with the increase in nuclear translocation of NF-E2-related factor-2 (Nrf2), an essential transcription factor for the regulation of HO-1 expression. Moreover, pretreatment of tin protoporphyrin IX (SnPP), a chemical inhibitor of HO-1, reversed the ability of isothamnetin to inhibit COX-2 expression. These results demonstrate that induction of HO-1 by isorhamnetin leads to a reduction in ROS production and its antioxidant property might contribute to the inhibition of COX-2 expression in response to inflammation.

Topics: Active Transport, Cell Nucleus; Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Cell Line; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Edema; Heme Oxygenase (Decyclizing); Inflammation; L-Lactate Dehydrogenase; Lipopolysaccharides; Macrophages; Metalloporphyrins; Mice; NF-E2-Related Factor 2; Nitric Oxide; Nitric Oxide Synthase Type II; Protoporphyrins; Quercetin; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species

High mobility group box 1 (HMGB1) protein is a crucial nuclear cytokine that elicits severe vascular inflammatory diseases. Oenanthe javanica (water dropwort) extract has anti-arrhythmic, neuroprotective and anti-diabetic activity. However, isorhamnetin-3-O-galactoside (I3G), an active compound from O. javanica, is not researched well for its biological activity. Here, we investigated the anti-inflammatory activities of I3G by monitoring the effects of I3G on the lipopolysaccharide (LPS) or cecal ligation and puncture (CLP)-mediated release of HMGB1 and HMGB1 or CLP-mediated modulation of inflammatory responses. I3G potently inhibited the release of HMGB1 and down-regulated HMGB1-dependent inflammatory responses in human endothelial cells. I3G also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. Further studies revealed that I3G suppressed the production of tumor necrosis factor-α and activation of nuclear factor-κB by HMGB1. In addition, I3G reduced CLP-induced HMGB1 release and sepsis-related mortality. Given these results, I3G should be viewed as a candidate therapeutic agent for the treatment of severe vascular inflammatory diseases such as sepsis or septic shock via inhibition of the HMGB1 signaling pathway.

Topics: Animals; Cell Movement; Down-Regulation; Galactosides; HMGB1 Protein; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Leukocytes; Lipopolysaccharides; Mice; NF-kappa B; Quercetin; Sepsis; Signal Transduction

In the present study the effect of quercetin and its major metabolites quercetin-3-glucuronide (Q3G) and isorhamnetin on inflammatory gene expression was determined in murine RAW264.7 macrophages stimulated with lipopolysaccharide. Quercetin and isorhamnetin but not Q3G significantly decreased mRNA and protein levels of tumor necrosis factor alpha. Furthermore a significant decrease in mRNA levels of interleukin 1β, interleukin 6, macrophage inflammatory protein 1α and inducible nitric oxide synthase was evident in response to the quercetin treatment. However Q3G did not affect inflammatory gene expression. Anti-inflammatory properties of quercetin and isorhamnetin were accompanied by an increase in heme oxygenase 1 protein levels, a downstream target of the transcription factor Nrf2, known to antagonize chronic inflammation. Furthermore, proinflammatory microRNA-155 was down-regulated by quercetin and isorhamnetin but not by Q3G. Finally, anti-inflammatory properties of quercetin were confirmed in vivo in mice fed quercetin-enriched diets (0.1 mg quercetin/g diet) over 6 weeks.

Topics: Animals; Anti-Inflammatory Agents; Cell Line; Cell Survival; Down-Regulation; Female; Flavonols; Gene Expression; Heme Oxygenase-1; Inflammation; Interleukin-1beta; Interleukin-6; Lipopolysaccharides; Macrophages; Mice; Mice, Inbred C57BL; MicroRNAs; Nitric Oxide Synthase Type II; Quercetin; Tumor Necrosis Factor-alpha