Quercetin is a plant-derived flavonoid found in fruits or vegetables that has antioxidant properties and acts as a free radical scavenger. We investigated the effects of quercetin on porcine oocyte nuclear maturation and embryonic development after parthenogenetic activation. We then evaluated the antioxidant activities of quercetin by measuring reactive oxygen species (ROS) levels in matured oocytes. Immature oocytes were untreated or treated with 1, 10, and 50 microg/mL quercetin during in vitro maturation (IVM). Quercetin treatment did not improve oocyte nuclear maturation, but significantly higher blastocyst rates (p < 0.05) of parthenogenetically activated oocytes were achieved when the IVM medium was supplemented with an adequate concentration of quercetin (1 microg/mL). However, cleavage rates and blastocyst cell numbers were not affected. Oocytes treated with 1 or 10 microg/mL quercetin had significantly lower (p < 0.05) levels of ROS than the control and group treated with the highest concentration of quercetin (50 microg/mL). Moreover, this highest concentration was detrimental to oocyte nuclear maturation and blastocyst formation. Based on our findings, we concluded that exogenous quercetin reduces ROS levels during oocyte maturation and is beneficial for subsequent embryo development.
Animals ; Antioxidants/administration & dosage/*pharmacology ; Dose-Response Relationship, Drug ; In Vitro Oocyte Maturation Techniques/*veterinary ; Oocytes/cytology/*drug effects/physiology ; Quercetin/administration & dosage/*pharmacology ; Reactive Oxygen Species/*metabolism ; *Swine

Quercetin is a plant-derived flavonoid found in fruits or vegetables that has antioxidant properties and acts as a free radical scavenger. We investigated the effects of quercetin on porcine oocyte nuclear maturation and embryonic development after parthenogenetic activation. We then evaluated the antioxidant activities of quercetin by measuring reactive oxygen species (ROS) levels in matured oocytes. Immature oocytes were untreated or treated with 1, 10, and 50 microg/mL quercetin during in vitro maturation (IVM). Quercetin treatment did not improve oocyte nuclear maturation, but significantly higher blastocyst rates (p < 0.05) of parthenogenetically activated oocytes were achieved when the IVM medium was supplemented with an adequate concentration of quercetin (1 microg/mL). However, cleavage rates and blastocyst cell numbers were not affected. Oocytes treated with 1 or 10 microg/mL quercetin had significantly lower (p < 0.05) levels of ROS than the control and group treated with the highest concentration of quercetin (50 microg/mL). Moreover, this highest concentration was detrimental to oocyte nuclear maturation and blastocyst formation. Based on our findings, we concluded that exogenous quercetin reduces ROS levels during oocyte maturation and is beneficial for subsequent embryo development.
Animals ; Antioxidants/administration & dosage/*pharmacology ; Dose-Response Relationship, Drug ; In Vitro Oocyte Maturation Techniques/*veterinary ; Oocytes/cytology/*drug effects/physiology ; Quercetin/administration & dosage/*pharmacology ; Reactive Oxygen Species/*metabolism ; *Swine

The objective of this study was to investigate the hypoglycemic effects of quercetin (QE) in animal models of diabetes mellitus (DM). A starch solution (1 g/kg) with and without QE (100 mg/kg) or acarbose (40 mg/kg) was orally administered to streptozotocin (STZ)-induced diabetic rats after an overnight fast. Postprandial plasma glucose levels were measured and incremental areas under the response curve were calculated. To study the effects of chronic feeding of QE, five-week-old db/db mice were fed an AIN-93G diet, a diet containing QE at 0.08%, or a diet containing acarbose at 0.03% for 7 weeks after 1 week of adaptation. Plasma glucose and insulin, blood glycated hemoglobin, and maltase activity of the small intestine were measured. Oral administration of QE (100 mg/kg) or acarbose (40 mg/kg) to STZ-treated rats significantly decreased incremental plasma glucose levels 30-180 min after a single oral dose of starch and the area under the postprandial glucose response, compared with the control group. QE (0.08% of diet) or acarbose (0.03% of diet) offered to db/db mice significantly reduced both plasma glucose and blood glycated hemoglobin compared to controls without significant influence on plasma insulin. Small intestine maltase activities were significantly reduced by consumption of QE or acarbose. Thus, QE could be effective in controlling fasting and postprandial blood glucose levels in animal models of DM.
Acarbose ; Administration, Oral ; Animals ; Blood Glucose ; Diabetes Mellitus ; Diet ; Fasting ; Glucose ; Hemoglobins ; Hyperglycemia ; Hypoglycemic Agents ; Insulin ; Intestine, Small ; Mice ; Models, Animal ; Plasma ; Quercetin ; Rats ; Starch ; Streptozocin

In this study, we investigated that anti-inflammatory effect of quercetin on picryl chloride(PCL)-induced contact dermatitis in BALB/c Mice. Experimental animals were divided into three groups and comprising five animals. All groups of oral administration was begun on the first day of PCL treatment and ceased on day 5. For the induction of contact dermatitis, BALB/c mice were sensitized with 40 microliter of 1.5% picryl choloride (PCL) to the left and right ear, respectively. Ear swelling responses were much weaker in high-dose group (100 mg/kg) than control group (0 mg/kg). Total serum IgE levels and histamine levels were measured by sandwich ELISA method using mouse IgE, histamine measuring Kit. Both total serum IgE and histamine levels were significantly decreased in high-dose group (100 mg/kg) than other groups. Degranulation of mast cells were also confirmed by Toluidine Blue (TB) staining method. In high-dose group (100 mg/kg), the number of mast cells were significantly decreased and there are many mast cells were shown degranulation in control group (0 mg/kg). All of these results demonstrate that the pharmacological actions of quercetin indicate their potential activity for allergic inflammatory diseases through the down-regulation of mast cell activation.
Administration, Oral ; Animals ; Dermatitis, Contact ; Down-Regulation ; Ear ; Enzyme-Linked Immunosorbent Assay ; Histamine ; Immunoglobulin E ; Mast Cells ; Mice ; Picryl Chloride ; Quercetin ; Tolonium Chloride

Onion (Allium cepa L.) contains high levels of dietary fibers and antioxidants, including vitamin C, D, and folates. Onion is also known as a quercetin-rich vegetable with high flavonoid content. Onion peel contains over 20 times more quercetin than onion flesh. The aim of this study was to examine the question of whether onion peel extract supplementation has an effect on maximal exercise performance in rat. Onion peel extracts were extracted with hot water. Thirty male Sprague Dawley rats were maintained on a pellet diet for one week, and then randomly divided into five groups: Normal control, Positive control (quercetin 20 mg/kg), Onion peel 4 mg/kg, Onion peel 20 mg/kg, and Onion peel 100 mg/kg. Oral administration was performed daily. The experimental period was four weeks. Thereafter, animals were then forced to swim in water and the maximal exercise performance period from the swimming start time to the exhausted time, in which they failed to rise to the surface of the water to breathe within a 7 second period, was measured. After necropsy, weights of gastrocnemius muscles were measured. Lactate dehydrogenase concentration in serum was measured using an enzymatic method, using a commercial kit. The maximal exercise performance period was significantly longer in the onion peel extracts fed groups, compared with the control group. The lactate dehydrogenase concentration of the onion peel extracts fed groups was significantly lower, compared with the control group. Based on these results, we suggest that onion peel water extract supplementation can enhance exercise capacity caused by the mechanism of decreasing lactate dehydrogenase concentration.
Administration, Oral ; Animals ; Antioxidants ; Ascorbic Acid ; Diet ; Dietary Fiber ; Humans ; L-Lactate Dehydrogenase ; Male ; Muscles ; Onions* ; Polyenes ; Quercetin ; Rats* ; Rats, Sprague-Dawley ; Swimming* ; Vegetables ; Water* ; Weights and Measures

OBJECTIVETo establish a RP-HPLC method for simultaneous determination of total quercetin, kaempferol and isorhamnetin in rat plasma after oral administration of Folium Mori extract (FME).

METHODSAfter a single dose of FME (110 mg/kg) was taken, rat plasma samples were collected. The samples were hydrolyzed with hydrochloric acid (c=3.0 mol/L), the mixed solution was extracted with ether acetone mixture. The total quercetin, kaempferol and isorhamnetin in plasma samples were determined by HPLC, pharmacokinetic parameters were calculated by DAS 3.0 software.

RESULTSThe method was linear over the concentration ranges of 0.0545-8.70, 0.0954-14.7 and 0.0545-8.55 μg/ml for quercetin, kaempferol and isorhamnetin, respectively (r=0.9979, 0.9993, 0.9981). The absolute recoveries were 85.3%-86.1%, 79.4%-86.7% and 62.8%-89.7%, respectively and the assay recoveries were all from 94.7% to 107%. The relative standard deviation (RSD) of intra-and inter-day were less than 9.5% and 9.8%, respectively. The main pharmacokinetic parameters were as follows: T(1/2z) was 92.7, 67.9 and 54.2 h; Tmax was 0.400, 0.400 and 3.87 h; AUC(0-∞) was 68.0, 67.5 and 32.8 mg/h/L; MRT(0-∞) was 128, 85.2 and 72.0 h for quercetin, kaempferol and isorhamnetin, respectively.

CONCLUSIONThe method established in this study is accurate, reliable and reproducible, and can be applied for determination of total quercetin, kaempferol and isorhamnetin in rat plasma after oral administration of FME; the pharmacokinetic studies showed that the distribution of drugs is rapid and elimination is very slow.

Administration, Oral ; Animals ; Chromatography, High Pressure Liquid ; methods ; Flavonols ; blood ; pharmacokinetics ; Kaempferols ; blood ; pharmacokinetics ; Male ; Plant Extracts ; pharmacokinetics ; Quercetin ; blood ; pharmacokinetics ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo establish the quality control standard of Xindi soft capsule.

METHODQuercetin, kaempferol and isorhamnetin were isolated by TLC with chloroform-ethyl formate-formic acid (5:4:1). The chromatographic separation was performed on a Diamonsil C18 column (4.6 mm x 250 mm, 5 microm). Acetonitrile-water-phosphoric (30:70:0.1) as mobile phase. The flow rate was 1 mL x min(-1) and column temperature was set at 40 degrees C. The UV detection wavelength was set at 254 nm.

RESULTQuercetin, Kaempferol and Isorhamnetin could be identified by TLC. Quercetin showed a good linear relationship at a range of 0.412-1.648 microg, r = 0.999 9, the average recovery was 96.8%, and RSD was 0.9% (n = 6). Kaempferol showed a good linear relationship at a range of 0.021-0.083 microg, r = 0.999 8, the average recovery was 96.9%, and RSD was 2.0% (n = 6). Isorhamnetin showed a good linear relationship at a range of 0.183-0.732 microg, r = 0.999 9, the average recovery was 97.1%, and RSD was 1.6% (n = 6).

CONCLUSIONThe method is accurate with the good reproducibility and can be used for the quality control of Xindi soft capsule.

Capsules ; Chromatography, Thin Layer ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; isolation & purification ; standards ; Flavonols ; analysis ; Hippophae ; chemistry ; Kaempferols ; analysis ; Plants, Medicinal ; chemistry ; Quality Control ; Quercetin ; analysis ; Reproducibility of Results

Ultraperformance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and the Metabolynx™ software, combined with mass defect filtering, were applied to identity the metabolites of quercetin-3-O-β-D-gluco-pyranosyl-(4→1)-α-L-rhamnoside (QGR) in rats after intravenous administration. MS(E) was used for simultaneous acquisition of precursor ion information and fragment ion data at high and low collision energy in one analytical run, which facilitated the rapid structural characterization of eight metabolites in rat plasma, urine and bile. The results indicated that methylation and glucuronidation were the major metabolic pathways of QGR in vivo. The present study provided important information about the metabolism of QGR which will be useful for fully understanding the mechanism of action of this compound. Furthermore, this work demonstrated the potential of the UPLC-Q-TOF/MS approach using Metabolynx for rapid and automated research of the metabolites of natural products.
Administration, Intravenous ; Animals ; Chromatography, High Pressure Liquid ; Ginkgo biloba ; chemistry ; Male ; Mass Spectrometry ; methods ; Plant Extracts ; metabolism ; Quercetin ; analogs & derivatives ; metabolism ; Rats, Sprague-Dawley

We investigated inhibitory effects of extract containing quercetin-3-O-beta-D-glucuronopyranoside (ECQ) extracted from Rumex Aquaticus Herba on indomethacin-induced gastric damage in Rats. Gastritis was induced in male Sprague-Dawley rats (200~220 g) by oral administration of indomethacin at a dose of 40 mg/kg. One hour before administration of indomethacin, animals were orally pretreated with ECQ at doses of 0.3, 1, 3 or 10 mg/kg. Six hours after indomethacin administration, the rats were sacrificed and the stomach was excised and opened along the greater curvature, and the surface area of gastric lesion was measured using optical microscope. Superoxide dismutase (SOD), catalase (CAT), myeloperoxidase (MPO) activities and malondialdehyde (MDA) levels were measured by ELISA. Western blot analysis was performed to detect protein expression of SOD-2. Linear hemorrhagic mucosal lesions were observed in the stomach 6 hours after oral administration of indomethacin. Pretreatment with ECQ significantly reduced the severity of the lesions in a dose-dependent manner. It also inhibited the reductions in SOD and CAT activities and SOD expression by the indomethacin-induced gastric damage. In addition, the pretreatment with ECQ significantly suppressed the elevation of the MPO activity and the MDA levels induced by indomethacin. These results suggest that ECQ has the inhibitory effects via antioxidative action against indomethacin-induced gastritis in rats.
Administration, Oral ; Animals ; Blotting, Western ; Catalase ; Cats ; Enzyme-Linked Immunosorbent Assay ; Gastritis ; Humans ; Indomethacin ; Male ; Malondialdehyde ; Peroxidase ; Quercetin ; Rats ; Rats, Sprague-Dawley ; Rumex ; Stomach ; Superoxide Dismutase

OBJECTIVETo establish the quality control standard for Xueyakang capsule.

METHODRadix Rehmanniae, Cacumen Platycladi, Folium Artemisiae Argyi, Folium Nelumbinis were identified by TLC, and the content of quercitrin was determined by HPLC.

RESULTThe TLC sports developed was fairly clear, the HPLC method showed good repeatability, and the average recovery of quercitrin was 100.7% with RSD 2.0%.

CONCLUSIONThe method is simple, accurate and can effectively control quality of Xueyakang capsule.

Antihypertensive Agents ; administration & dosage ; chemistry ; isolation & purification ; Artemisia ; chemistry ; Capsules ; Chromatography, High Pressure Liquid ; Chromatography, Thin Layer ; Cupressaceae ; chemistry ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; isolation & purification ; Nelumbo ; chemistry ; Plants, Medicinal ; chemistry ; Quality Control ; Quercetin ; analysis ; Rehmannia ; chemistry