Quercetin Supplementation Research Articles

Hemato-Biochemical Alterations Mediated by Carbendazim Exposure and Protective Effect of Quercetin in Male Rats

The main objective of study was to investigate the effect of Carbendazim (CBZ) a most popular agriculture fungicide on hemato-biochemical alterations in male rats and possible ameliorative effect of quercetin. Sprague Dawley male rats were administered CBZ @100, 200 and 400 mg/kg body weight, PO and quercetin (25mg/kg body weight, PO ) alone and concomitant in corn oil for the period of 28 days. At the end of exposure period, blood was collected and hemato-biochemical parameters were evaluated in blood and plasma samples. Sub-acute exposure of carbendazim resulted in non-significant decrease (p > 0.05) in haemoglobin, PVC and TEC and increase in MCV, MCH and platelets count in CBZ treated groups. Moreover, administration of CBZ significantly increased (p < 0.05) the plasma ALT, AST, ALP, cholesterol and triglyceride while, significantly decreased (p < 0.05) the plasma protein and globulin level was noticed. Non-significant change in calcium, chloride and phosphorous was observed in CBZ alone treated groups. However, quercetin supplementation concomitant in CBZ treated animals prevented and restored the alterations caused by exposure of CBZ. This study concluded that quercetin has ability to ameliorate the toxic effect caused by CBZ on hemato-biochemical biomarkers in living beings.

Quercetin and Epigallocatechin Gallate in the Prevention and Treatment of Obesity: From Molecular to Clinical Studies.

Obesity is a worldwide epidemic, which is characterized by the excess accumulation of adipose tissue and to an extent that impairs both the physical and psychosocial health and well-being. There are several weight-loss strategies available, including dietary modification, pharmacotherapy, and bariatric surgery, but many are ineffective or not a long-term solution. Bioactive compounds present in medicinal plants and plant extracts, like polyphenols, constitute the oldest and most extensive form of alternative treatments for the prevention and management of obesity. Their consumption is currently increasing in the population due to the high cost, potential adverse effects, and limited benefits of the currently available pharmaceutical drugs. A great number of studies has explored how dietary polyphenols can interfere with the different mechanisms associated with obesity development. They suggest that these compounds can decrease energy and food intake, lipogenesis, and preadipocyte differentiation and proliferation, while increasing energy expenditure, lipolysis, and fat oxidation. Both quercetin, one of the most common dietary flavonols in the western diet, and epigallocatechin gallate (EGCG), the most abundant polyphenol in green tea, exhibit antiobesity effects in adipocyte cultures and animal models. However, the extrapolation of these potential benefits to obese humans remains unclear. Although quercetin supplementation does not seem to exert any beneficial effects on body weight, this polyphenol could prevent the obesity-associated mortality by reducing cardiovascular disease risk. An important consideration for the design of further trials is the occurrence of gene polymorphisms in key enzymes involved in flavanol metabolism, which determines a subject's sensitivity to catechins and seems, therefore, crucial for the success of the antiobesity intervention. Although the evidence supporting antiobesity effects is more consistent in EGCG than with quercetin studies, they could still be beneficial by reducing the cardiovascular risk of obese subjects, rather than inducing body weight loss.

ZNACZENIE KWERCETYNY JAKO ZWIĄZKU WSPOMAGAJĄCEGO WYDOLNOŚĆ W DIECIE SPORTOWCA

Kwercetyna (3,3’,4’,5,7-pentahydroksyflawon) naturalnie występująca w wielu surowcach oraz produktach spożywczych pochodzenia roślinnego, stanowi stały składnik diety człowieka. Udowodniono jej wielokierunkowe działanie prozdrowotne oraz przeciwutleniające, istotne z punktu widzenia dietetycznego. Wyniki wykonanych badań nad znaczeniem kwercetyny w diecie osób aktywnych fizycznie, jako związku o działaniu wspomagającym adaptację organizmu do obciążeń treningowych są jednak niejednoznaczne. Celem usystematyzowania wiedzy z tego zakresu, dokonano kierunkowego przeglądu aktualnych (nie starszych niż 10 lat) badań naukowych sklasyfikowanych w międzynarodowych bazach, m. in. Web od Science, Science Direct, PubMed, który dotyczył kwercetyny, flawonoidów i przeciwutleniaczy oraz stresu oksydacyjnego, aktywności fizycznej i VO2max.Obiecujące wyniki badań nad związkiem suplementacji kwercetyną ze zwiększeniem biogenezy mitochondrialnej, wykonanych na modelu zwierzęcym, nie zostały potwierdzone u ludzi. Nie wykazano również działania ochronnego przed stresem oksydacyjnym, stanem zapalnym organizmu oraz uszkodzeniami mięśni szkieletowych indukowanymi intensywnym wysiłkiem fizycznym. Jednakże wpływ suplementacji na zdolności wytrzymałościowe organizmu został częściowo potwierdzony wśród niewytrenowanych, lub o umiarkowanym poziomie wytrenowania zawodników.Opublikowane jak dotąd wyniki badań nie umożliwiają wysunięcia wniosku dotyczącego zasadności stosowania suplementacji kwercetyną w sporcie. Niewątpliwie, temat ten wciąż jest niedostatecznie poznany i stanowi potencjał dla dalszych badań, których ważnym aspektem jest także określenie dokładnej dawki suplementu, wykazującej pożądane działanie i określenie potencjalnych działań niepożądanych nadmiernego spożycia kwercetyny oraz interakcji z innymi suplementami.

Endogenous and Exogenous Modulation of Nrf2 Mediated Oxidative Stress Response in Bovine Granulosa Cells: Potential Implication for Ovarian Function.

Nrf2 is a redox sensitive transcription factor regulating the expression of antioxidant genes as defense mechanism against various stressors. The aim of this study is to investigate the potential role of noncoding miRNAs as endogenous and quercetin as exogenous regulators of Nrf2 pathway in bovine granulosa cells. For this cultured granulosa cells were used for modulation of miRNAs (miR-28, 153 and miR-708) targeting the bovine Nrf2 and supplementation of quercentin to investigate the regulatory mechanisms of the Nrf2 antioxidant system. Moreover, cultured cells were treated with hydrogen peroxide to induce oxidative stress in those cells. Our results showed that, oxidative stress activated the expression of Nrf2 as a defense mechanism, while suppressing the expression of those miRNAs. Overexpression of those miRNAs resulted in downregulation of Nrf2 expression resulted in higher ROS accumulation, reduced mitochondrial activity and cellular proliferation. Quercetin supplementation showed its protective role against oxidative stress induced by H2O2 by inducing the expression of antioxidant enzymes. In conclusion, this study highlighted the involvement of miR-153, miR-28 and miR-708 in regulatory network of Nrf2 mediated antioxidant system in bovine granulosa cells function. Furthermore, quercetin at a low dose played a protective role in bovine granulosa cells against oxidative stress damage.

Clinical effectiveness of quercetin supplementation in the management of weight loss: a pooled analysis of randomized controlled trials.

Purpose: The previous investigations which considered the possible effect of the quercetin supplementation for overweight and obesity have led to inconsistent results. Here, we aimed to evaluate the effects of quercetin on weight loss using a meta-analysis of randomized controlled clinical trials (RCTs).Methods: Relevant studies were systematically searched from the MEDLINE, EMBASE, Google Scholar, and Scopus databases. RCTs that investigated the effects of quercetin on weight loss in humans were included for quality assessment, meta-analyses, sensitivity analysis, subgroup analyses, and publication bias assessment. Effect size was expressed as weighted mean difference (WMD) and 95% CI by using a random-effects model. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to rate the level of evidence.Results: Nine RCTs (11 treatment arms) with 525 participants were finally included for data pooling. Our meta-analysis revealed that daily quercetin supplementation did not significantly affect the body weight (WMD: −0.35 kg, 95% CI: −2.03, 1.33; P=0.68), body mass index (WMD: −0.04 kg/m2, 95% CI: −0.54, 0.45; P=0.87), waist circumference (WMD: −0.37 cm, 95% CI: −1.81, 1.06; P=0.61), and waist to hip ratio (WMD: −0.01, 95% CI: −0.03, 0.01; P=0.48). Subgroup analysis could not identify factors significantly influencing these parameters. These results were robust in sensitivity analysis, and no significant publication bias was found.Conclusion: The current evidence suggests that quercetin intake did not show a notably favorable effect on weight loss. Future well-designed and long-term clinical trials are required to confirm these results.

Quercetin mitigates anxiety-like behavior and normalizes hypothalamus-pituitary-adrenal axis function in a mouse model of mild traumatic brain injury.

Mild traumatic brain injury (mTBI) is a major public health risk for developing anxiety-related disorders and hypothalamus-pituitary-adrenal (HPA) axis dysregulation in humans. Extensive research has shown that dietary intake or supplementation of the natural flavonoid quercetin might be useful for treating anxiety-related symptoms. The objectives of this study were to determine whether quercetin treatment can attenuate anxiogenic-like behaviors and normalize HPA axis function in mice with mTBI. Animals subjected to mTBI were treated daily with quercetin (50 mg/kg) or diazepam (positive control, 3 mg/kg) for 14 days. Four behavioral tests (open field, plus maze, light-dark box, and zero maze) were used to assess anxiety-related behaviors in mice. To evaluate HPA axis function, adrenocorticotropic hormone and corticosterone were measured in the serum of mice after the anxiety tests. Quercetin treatment was found to significantly reduce anxiety-like behaviors in mTBI-induced mice. A strength of this study is the consistency of results among anxiety tests. The dysregulation of the HPA axis in mTBI-induced mice treated with quercetin was also attenuated, with decreased levels of adrenocorticotropic hormone and corticosterone. The effects of quercetin were comparable with those of diazepam treatment. Taken together, these results suggest that quercetin might be useful for treating anxiety-related symptoms and HPA axis hyperreactivity in patients with mTBI.

Effects of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials.

This systematic review and meta-analysis of randomized controlled trials was performed to determine the effect of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders. Databases including PubMed, MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials were searched until August 30, 2018. Nine studies with 10 effect sizes out of 357 selected reports were identified eligible to be included in current meta-analysis. The pooled findings indicated that quercetin supplementation did not affect fasting plasma glucose (FPG), homeostasis model of assessment-estimated insulin resistance, and hemoglobin A1c levels. In subgroup analysis, quercetin supplementation significantly reduced FPG in studies with a duration of ≥8weeks (weighted mean difference [WMD]: -0.94; 95% confidence interval [CI; -1.81, -0.07]) and used quercetin in dosages of ≥500mg/day (WMD: -1.08; 95% CI [-2.08, -0.07]). In addition, subgroup analysis revealed a significant reduction in insulin concentrations following supplementation with quercetin in studies that enrolled individuals aged <45years (WMD: -1.36; 95% CI [-1.76, -0.97]) and that used quercetin in dosages of ≥500mg/day (WMD: -1.57; 95% CI [-1.98, -1.16]). In summary, subgroup analysis based on duration of ≥8weeks and used quercetin in dosages of ≥500mg/day significantly reduced FPG levels.

Dietary Supplementation of Quercetin and the Reproductive Functions in Hypertensive Male Rats

AbstractBackground: Hypertension is considered one of the com-monest medical problems and affects more than 25% of the general population, with its prevalence increases with age. It is associated with a wide variety of health challenges like stroke, heart failure, renal failure and reproductive disorders.Aim of Study: The prevention of hypertension induced reproductive impairment remains unclear. Hence, the aim of the present study was to investigate the possible protective effects of quercetin on male reproductive functions in L-NAME- induced hypertensive rats.Material and Methods: 50 Male Wister Albino rats (200- 220g) were divided into 5 groups 10 per each. G1: The control group was placed on the basal diet (received saline with the same volume used to dissolve L-NAME and quercetin by gavage) for 4 weeks. G 2: The Quercetin group was adminis-tered with Quercetin 50mg/Kg b.w. by gavage for 4 weeks. G 3: The L-NAME group (hypertensive induced group received L-NAME (40mg/Kg/day by gavage) for 4 weeks. G 4: The L-NAME plus atenolol received L-NAME plus atenolol (10 mg/kg/day) by gavage for 4 weeks. G 5: The L-NAME plus Quercetin received L-NAME (40mg/Kg/day) plus quercetin 50mg/Kg b.w. by gavage for 4 weeks.Results: Quercetin abrogated the mean blood pressure elevation induced by L-NAME. Administration of quercetin increased the antioxidant enzyme activities and glutathione, whereas it suppressed the oxidative stress biomarkers and the arginase activity. Quercetin significantly restored hypertension induced impairment of luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone hormone. Quer-cetin improves the sperm motility and viability. Histopatho-logical findings supported our results.In Conclusion: Quercetin supplementation may be con-sidered a beneficial approach targeting reproductive deficits in male hypertensive patients.

Effects of Treatment with Quercetin on the Quality of Cryopreserved Bovine Semen

Background: Semen cryopreservation is one of the most common biotechnologies in the reproduction of animals of agricultural interest, especially bulls. However, cryopreservation can be harmful to sperm cells, with susceptibility to oxidative stress being one of the causes. The addition of antioxidants such as quercetin may inhibit and/or reduce such damage, reducing fertility. Quercetin can increasing sperm motility and interaction capacity between spermatozoa-oocyte, to increase cellular metabolism and reduced DNA fragmentation and oxidation following thawing. Therefore, the objective of this study was to evaluate the protective effect of quercetin on the metabolism of bovine semen following thawing.Material, Methods &amp; Results: Three Brahman bulls in reproduction age and previously considered fit for reproduction were used. The semen samples were collected via the electroejaculation method, and the samples were homogenized to form pooled semen from three ejaculates, which was diluted in Tris-yolk egg-glicerol diluent medium. Quercetin was added to diluent, to final concentrations of 0, 5, 10, 15 and 20 μg.mL-1 in each group. The samples were kept frozen in straws of 500 μL, with concentration of 40,000,000 spermatozoid / mL for 15 days and were thawed in water at 36°C for 30 s. All the tests was performed in five replicates. The cell metabolism status was evaluated by quantification of superoxide radical production with a nitroblue tetrazolium test (NBT) and scanning spectrophotometry. By spermatic evaluation, the following parameters were evaluated via the computerized system of sperm analysis (CASA): total motility (TM, %), progressive motility (PM, %), velocity curved line (VCL, mm/s), velocity straight line (VSL, mm/s), velocity average path (VAP, mm/s), distance curved line (DCL, mm), distance straight line (DSL, mm), distance average path (DAP, mm), amplitude of lateral head displacement (ALH, mm), beat cross frequency (BCF, Hz), wobble (WOB = VAP/VCL), linearity (LIN, VSL:VCL) and straightness (STR, VSL:VAP). And by surface analysis through scanning electron microscopy (SEM). The NBT test demonstrated an increase in cell metabolism of approximately 40% up to the limit of 15 µg.mL-1 quercetin. The parameters of CASA pertaining to velocity (VCL, VSL, VAP) and as a consequence, wobble and linearity increased as a function of the quercetin concentration until 20 µg.mL-1, which was shown to be statistically significant. No significant morphological changes between groups were observed by the SEM technique.Discussion: The reduction of NBT indicates oxidative metabolism, being an indirect measure of the oxygen dependent activity of the cells, therefore the results demonstrate that quercetin supplementation increased the number of cells with high metabolic activity. Regarding the evaluation of CASA, according to the literature, some parameters are reliable estimates of the fertilization capacity of the human spermatozoon, among them, the VCL. In this study, all speeds were increased with Quercetin, including LCV, demonstrating its importance in supplementation in bovine seminal diluent. Scanning electron microscopy evaluates the structural morphology of the cell surface. As with previous results, in this study, all cells lost the acrosome. However, this type of damage was already expected in thawed spermatozoa. In addition, no other significant changes were observed in the morphology of the membrane or other parts of the sperm. In general, the results presented here suggest that the addition of quercetin to the seminal diluent before freezing improve spermatic quality, which manifests itself as faster spermatozoa and may higher fertilization rates.

Neuro-protective potential of quercetin during chlorpyrifos induced neurotoxicity in rats

Chlorpyrifos (CPF) has been considered as one of the most potent organophosphates and is linked to several neurological disorders. On the other hand, Quercetin is a vital plant flavanoid and has been reported to regulate a number of physiological processes in the central nervous system. The present study was conducted to investigate the protective potential of quercetin during chlorpyrifos induced neurotoxicity. Female Wistar rats weighing 150–200 g were divided into four different groups viz: Normal control, CPF treated (13.5 mg/kg.b.wt. every alternate day), Quercetin treated (50 mg/kg.b.wt./day) and combined CPF and quercetin-treated. All the treatments were carried out for a total duration of eight weeks. Chlorpyrifos treatment showed significant alterations in the cognitive behavior and motor activities of rats, which were appreciably improved upon simultaneous supplementation with quercetin. Further, CPF treatment caused a significant inhibition in the enzyme activities of acetylcholinesterase and choline acetyltransferase, but caused an increase in the levels of acetylcholine in the brain. Further, chlorpyrifos exposure significantly elevated the levels of lipid peroxidation and protein carbonyl contents as well as the activities of catalase, superoxide dismutase, which were interestingly found to be decreased following co-treatment with quercetin. In contrast, CPF treatment decreased the activities of glutathione reductase, transferase, as well as levels of reduced and total glutathione in both the cerebrum and cerebellum but co-administration of quercetin, increased these levels. Chlorpyrifos treatment altered the neuro-histoarchitecture, which showed improvement upon quercetin supplementation. Hence, this study suggests that quercetin can be used as a prophylactic intervention to prevent CPF induced neurotoxicity.

In vitro bioaccessibility and bioavailability of quercetin from the quercetin-fortified bread products with reduced glycemic potential

Quercetin, a plant-extracted flavonol, is a potent inhibitor of carbohydrate digestive enzymes. This study aimed to examine: (1) the extent to which quercetin altered the starch digestion and the glycemic potential of the fortified western baked bread as well as oriental steamed bread, (2) the matrix effects of bread on the potential bioaccessibility and bioavailability of quercetin. The starch digestion of bread was quantitatively evaluated by determination of starch digestion rate (k) via a developed mathematical model. Results showed a significant reduction of k for the 1.5, 3, and 6% quercetin-fortified baked and steamed bread compared to the controls by up to 18.3%. The predicted GIs of the baked bread samples with quercetin were significantly reduced in comparison to control bread. Moreover, the potential bioaccessibility of quercetin incorporated in bread products was significantly higher than that of quercetin supplement probably as a result of the protective effects from food matrix.

Effect of quercetin supplementation on the growth, feed efficiency and serum hormone levels of New Zealand White rabbits

Meat rabbits could provide a new avenue for agricultural development in South Africa, and flavonoids may be able to improve their live performance. This study investigated the effects of quercetin dihydrate (0 and 2 g/kg feed) on the growth parameters and serum-free triiodothyronine (fT3), free thyroxine, somatotropin, and cortisol levels of growing rabbits. It also provides the first growth and feed conversion ratio (FCR) data for South African New Zealand Whites. Control (Ctrl) and quercetin-supplemented (Qrc) diets were provided to 34 (16 male, 18 female) and 32 (15 male, 17 female) rabbits, respectively, from 5 to 12 weeks old. Live performance was measured weekly, and serum hormone levels were determined at 11 weeks old. Overall, the rabbits performed well for live weight and growth rate, growing from 1052 ± 13.4 g to 3192 ± 45.3 g (5-12 weeks). Females had higher cortisol levels than males, as found for other species (female = 10.9 ng/mL, male = 3.89 ng/mL). Qrc rabbits tended to have a higher overall FCR than Ctrl rabbits (Ctrl = 3.83, Qrc = 4.01), possibly due to lower feed digestibility, and had smaller sex differences in growth and FCR than Ctrl rabbits, possibly owing to xenoestrogenic activity. They also tended to have higher fT3 levels than Ctrl rabbits (Ctrl = 3.62 ng/mL, Qrc = 4.98 ng/mL), possibly owing to the inhibition of binding to transthyretin. However, it does not seem that the provision of quercetin is commercially justified for improving the live performance of rabbits.

Protective effects of quercetin supplementation against short-term toxicity of cadmium-induced hematological impairment, hypothyroidism, and testicular disturbances in albino rats.

The aim of this study was to evaluate the probable protective effect of quercetin (QUE) against cadmium (Cd)-induced sub-chronic toxicity in rats. Adult male rats were given either Cd (as cadmium chloride; 5mg/kg) alone or in combination with QUE (50mg/kg) daily for 4weeks by oral gavage. At the end of the experimental period, Cd accumulation, and selected hematological, thyroid, and reproductive markers were assessed. Results revealed that Cd treatment significantly increased Cd concentrations in blood, thyroid gland, and testicular tissue of rats. Cd also caused a decline in hemoglobin content, hematocrit value, and total erythrocyte and leucocyte counts. Further, significant suppressions in the blood levels of hormones related to thyroid gland function, and male reproductive hormones (i.e., testosterone, luteinizing hormone and follicle-stimulating hormone), were observed in Cd-treated rats compared to the control. In parallel, low sperm count and sperm motility, increased sperm abnormalities, and marked pathology occurred in testis. Combination with QUE recorded amelioration of the deleterious effects of Cd, involving regulation of hematological toxicity and thyroid hormonal levels and subsequently modulation of testicular function. In conclusion, it appears that dietary QUE can rescue from Cd-induced hematological dysfunctions and testicular damage by reversing the hypothyroid state.

The Effects of Quercetin Supplementation on Eccentric Exercise-Induced Muscle Damage.

The aim of the present investigation was to test the hypothesis that quercetin (Q) may prevent the strength loss and neuromuscular impairment associated with eccentric exercise-induced muscle damage (EEIMD). Twelve young men (26.1 ± 3.1 years) ingested either Q (1000 mg/day) or placebo (PLA) for 14 days using a randomized, double-blind, crossover study design. Participants completed a comprehensive neuromuscular (NM) evaluation before, during and after an eccentric protocol able to induce a severe muscle damage (10 sets of 10 maximal lengthening contractions). The NM evaluation comprised maximal voluntary isometric contraction (MVIC) and force–velocity relationship assessments with simultaneous recording of electromyographic signals (EMG) from the elbow flexor muscles. Soreness, resting arm angle, arm circumference, plasma creatine kinase (CK) and lactate dehydrogenase (LDH) were also assessed. Q supplementation significantly increased the isometric strength recorded during MVIC compared to baseline (+4.7%, p < 0.05). Moreover, the torque and muscle fiber conduction velocity (MFCV) decay recorded during the eccentric exercise was significant lower in Q compared to PLA. Immediately after the EEIMD, isometric strength, the force–velocity relationship and MFCV were significantly lower when participants were given PLA rather than Q. Fourteen days of Q supplementation seems able to attenuate the severity of muscle weakness caused by eccentric-induced myofibrillar disruption and sarcolemmal action potential propagation impairment.

Effect of quercetin on oxidative stress and liver function in beta-thalassemia major patients receiving desferrioxamine: A double-blind randomized clinical trial.

Background:Blood transfusion therapy is lifesaving for beta-thalassemia major patients, yet it indirectly causes complications such as oxidative stress and liver dysfunction. In the present study, we investigated the effect of quercetin supplementation on oxidative stress and liver function in beta-thalassemia major patients.Materials and Methods:In this double-blind clinical trial, 84 beta-thalassemia patients who received desferrioxamine (DFO) were randomly assigned to two groups; the treatment group received 500 mg quercetin tablet daily for 12 weeks, and the control group received placebo. In addition to demographic and anthropometric assessment, malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were biochemically assessed to detect the effect of quercetin on oxidative stress and liver function, respectively. The data were analyzed using SPSS 21. P < 0.05 was considered statistically significant.Results:Before adjusting for confounding variables, within-group comparison showed that quercetin supplementation reduced ALT (P < 0.001) and TAC (P < 0.001) significantly. Between-group comparison using analysis of covariance analysis though showed that quercetin could significantly reduce ALT (P = 0.002), but there was an insignificant increase in SOD and TAC, and insignificant decrease in GPx, MDA, AST, and ALP (P > 0.05).Conclusion:According to our results, consumption of 500 mg quercetin supplement daily for 3 months along with DFO treatment might be able to alter liver function, but not the oxidative stress in beta-thalassemia major patients.

Influence of Dietary Inclusion of Oil and Quercetin Supplementation on Carcass Characters and Meat Quality Attributes of Broiler Chickens

Influence of Dietary Inclusion of Oil and Quercetin Supplementation on Carcass Characters and Meat Quality Attributes of Broiler Chickens

Glyphosate disrupts redox status and up-regulates metallothionein I and II genes expression in the liver of adult rats. Alleviation by quercetin.

The present work evaluated the possible protective effects of quercetin against glyphosate-induced hepatotoxicity in adult rats. Rats were randomly divided into three groups: a control group (C), a glyphosate-treated group (Gly) and a group treated with both glyphosate and quercetin (Gly+QE). During the experimental period (15 days), glyphosate (50 mg/kg b.w.) was administered every two days by intraperitoneal way while quercetin (20 mg/kg b.w./day) was administered daily by gavage. Glyphosate-induced hepatic oxidative stress was evidenced by the increased levels of malondialdehyde, hydrogen peroxide, advanced oxidation protein products and protein carbonyls with a significant decrease in enzymatic (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (non-protein thiols, glutathione, vitamin C) antioxidants. Plasma biomarkers of hepatotoxicity (AST, ALT, ALP, γ-GT, albumin) were also altered. Moreover, glyphosate induced DNA damage, up-regulated metallothionein (MT I and MT II) genes expression and provoked histopathological changes in rats' liver. Quercetin supplementation to glyphosate-treated rats markedly ameliorated all the parameters indicated above as well as the liver histoarchitecture. Therefore, quercetin might have beneficial effects against glyphosate-induced hepatotoxicity in rats.

60 Quercetin protects bovine pre-implantation embryos against oxidative stress via activation of Nrf2 signaling pathway

High atmospheric oxygen level during in vitro embryo culture system is reported to induce oxidative stress, leading to an increased intracellular reactive oxygen species (ROS) accumulation and lower the quality and development of the embryos. The Nrf2 is a redox sensitive transcription factor, which regulates the antioxidant machinery against oxidative stress in bovine pre-implantation embryos (Amin et al. 2014Mol. Reprod. Dev. 81, 497-513). Quercetin is a plant-derived flavonoid found in fruits and vegetables with antioxidant, anti-inflammatory, and anti-apoptotic properties. The effect of these antioxidants on the development and quality of bovine pre-implantation embryos with respect to the activation of the Nrf2 signalling pathways is not yet discovered. Here, we aimed to investigate the effect of quercetin supplementation on the activation of the Nrf2 signalling pathway and the subsequent impact on the quality of bovine embryos. For this, presumptive bovine zygotes were cultured in SOFaa embryo culture media supplemented with or without 10 µM quercetin (482 and 485 zygotes, respectively) and incubated under high oxygen level (20%) conditions. Day 7 and Day 8 blastocysts were analysed for the accumulation intracellular ROS and mitochondrial activity using H2DCFDA and MitoTracker® Red, respectively. Thereafter, blastocysts from both groups were subjected to total RNA isolation using Norgen total RNA purification plus kit (BioTek, Winooski, VT, USA). The relative abundance of Nrf2 and its downstream antioxidant genes (NQO1, PRDX1, SOD1, and CAT) was quantified using quantitative PCR. Moreover, the protein level of Nrf2 was detected using immunofluorescence staining. Data from 4 independent biological replicates were statistically analysed using a 2-tailed Student’s t-test. A significant difference in the mean value among treatments was determined at P=0.05. Results showed that quercetin supplementation in embryo culture medium significantly increased the blastocyst total cell number both at Day 7 (125±7.98 v. 100±3.74; P=0.007) and Day 8 (128±4.49 v. 95±3.15; P&amp;lt;0.0001). However, no difference was observed in the quercetin-treated group compared with control with respect to the cleavage rate (85.89±1.11v. 83.86±1.27; P=0.2) as well as the blastocyst rate at Day 7 (24.57±4.94 v. 27.23±1.68; P=0.64) and Day 8 (41.17±3.70 v. 38.87±0.85; P=0.58). Interestingly, quercetin-supplemented blastocysts showed a significant reduction in intracellular ROS level and increment in the mitochondrial activity compared with untreated counterparts. Supplementation of quercetin activated the Nrf2 transcriptional factor both at the mRNA and protein level, which subsequently activated the transcription of the aforementioned downstream antioxidant genes. In conclusion, supplementation of quercetin to embryo culture media protects embryos against oxidative stress by activating the Nrf2-mediated oxidative stress response mechanism, which leads to reduced accumulation of ROS and elevated mitochondrial activity.

146 Quercetin supplementation during boar semen thawing and incubation improves the in vitro production of pig embryos

Elevated levels of reactive oxygen species in the in vitro environment cause oxidative stress, which leads to membrane damage, decreased fertility, and morphological deformities of spermatozoa. Antioxidants, such as quercetin (a polyphenol flavonoid), are often supplemented to reduce the effects of oxidative stress on spermatozoa. Supplementing frozen-thawed boar semen with quercetin improves sperm forward progressive motility, viability and lipid peroxidation up to 10h after thawing. However, the effects of fertilizing with quercetin-supplemented sperm are unknown. Therefore, the objective of this study was to determine the effects of supplementing quercetin (0.25, 0.50, 0.75mM) during the thawing and incubation of frozen-thawed boar semen on oocyte fertilization characteristics (n=400) and subsequent embryonic development (n=1340) at 48 and 144h for cleavage and blastocyst formation, respectively. Oocytes from aspired aspirated mature follicles (3-6mm diameter) were obtained from a local abattoir and matured in medium 199 for 40 to 44h at 38.5°C in an atmosphere of 5% CO2. Fertilization was performed using pooled frozen-thawed semen from 3 different boars, and co-incubation of the sperm (2×105 sperm mL−1) and oocytes (30 oocytes/well) lasted for 6 to 8h at 38.5°C in an atmosphere of 5% CO2. Data were analysed using ANOVA with the main effects including treatment, well and replicate. Chi-squared analysis was used to determine percentages of embryos reaching the different developmental stages for each treatment. There were no differences in penetration rates and male pronuclear formation between treatment groups; however, supplementation of 0.25 (18.18±10.63%), 0.50 (20.93±9.89%) and 0.75mM (18.07±12.02%) quercetin significantly decreased (P&amp;lt;0.05) polyspermic penetration rates compared with no supplementation (40.00±11.34%). Embryos produced from frozen-thawed boar sperm supplemented with 0.25 and 0.50mM quercetin had a significantly higher percentage (P&amp;lt;0.05) of embryos reaching the 2-cell stage of development by 48h after IVF (75.00±7.89%, 68.75±2.23%, respectively) compared with 0.75mM quercetin supplementation (64.62±3.88%) and no supplementation (62.97±4.11%). Supplementation of 0.25 (44.12±6.23%), 0.50 (43.75±7.02%) and 0.75mM (43.08±2.98%) quercetin to the sperm significantly increased (P&amp;lt;0.05) the percentage of embryos reaching the blastocyst stage of development by 144h after IVF compared with no supplementation (28.27±8.07%). These results indicate that supplementing frozen-thawed boar semen with quercetin decreases the incidence of polyspermic penetration and improves early embryonic development in pigs.

Impact of quercetin on tight junctional proteins and BDNF signaling molecules in hippocampus of PCBs-exposed rats.

Polychlorinated biphenyls (PCBs) consist of a range of toxic substances which are directly proportional to carcinogenesis and tumor-promoting factors as well as having neurotoxic properties. Reactive oxygen species, which are produced from PCBs, alter blood–brain barrier (BBB) integrity, which is paralleled by cytoskeletal rearrangements and redistribution and disappearance of tight junction proteins (TJPs) like claudin-5 and occludin. Brain-derived neurotrophic factor (BDNF), plays an important role in the maintenance, survival of neurons and synaptic plasticity. It is predominant in the hippocampal areas vital to learning, memory and higher thinking. Quercetin, a flavonoid, had drawn attention to its neurodefensive property. The study is to assess the role of quercetin on serum PCB, estradiol and testosterone levels and mRNA expressions of estrogen receptor α and β, TJPs and BDNF signaling molecules on the hippocampus of PCBs-exposed rats. Rats were divided into 4 groups of 6 each. Group I rats were intraperitoneally (i.p.) administered corn oil (vehicle). Group II received quercetin 50 mg/kg/bwt (gavage). Group III received PCBs (Aroclor 1254) at 2 mg/kg bwt (i.p). Group IV received quercetin 50 mg/kg bwt (gavage) simultaneously with PCBs 2 mg/kg bwt (i.p.). The treatment was given daily for 30 days. The rats were euthanized 24 h after the experimental period. Blood was collected for quantification of serum PCBs estradiol and testosterone. The hippocampus was dissected and processed for PCR and Western blot; serum PCB was observed in PCB treated animals, simultaneously quercetin treated animals showed PCB metabolites. Serum testosterone and estradiol were decreased after PCB exposure. Quercetin supplementation brought back normal levels. mRNA expressions of estrogen α and β were decreased in the hippocampus of PCB treated rats. TJPS and BDNF signalling molecules were decreased in hippocampus of PCB treated rats. Quercetin supplementation retrieved all the parameters. Quercetin alone treated animals showed no alteration. Thus in PCB caused neurotoxicity, quercetin protects and prevents neuronal damage in the hippocampus.