Quercetin Supplementation Research Articles

Dietary Flavonoid Quercetin Supplement Promotes Antiviral Innate Responses Against Vesicular Stomatitis Virus Infection by Reshaping the Bacteriome and Host Metabolome in Mice.

Active ingredients in functional foods exhibit broad-spectrum antiviral activity. The objective of this study is to investigate the protective effect of quercetin derived from bee propolis, a natural product with antiviral activity and modulating effects on the gut microbiota, against vesicular stomatitis virus (VSV) infection. Through a cellular-based study, this study demonstrates that quercetin can modulate the activity of interferon-regulating factor 3 (IRF3). In vivo, it shows that quercetin protects mice from VSV infection by enhancing interferon production and inhibiting the production of proinflammatory cytokines. The study conducts 16S rRNA-based gut microbiota and nontargets metabolomics analyses to elucidate the mechanisms underlying quercetin-mediated bidirectional communication between the gut microbiome and host metabolome during viral infection. Quercetin not only ameliorates VSV-induced dysbiosis of the intestinal flora but also alters serum metabolites related to lipid metabolism. Cross-correlations between the gut bacteriome and the serum metabolome indicate that quercetin can modulate phosphatidylcholine (16:0/0:0) and 5-acetylamino-6-formylamino-3-methyluracil to prevent VSV infection. This study systematically elucidates the anti-VSV mechanism of quercetin through gut bacteriome and host metabolome assays, offering new insights into VSV treatment and revealing the mechanisms behind a novel disease management strategy using dietary flavonoid supplements.

Quercetin in semen extender improves frozen-thawed spermatozoa quality and in-vivo fertility in crossbred Kamori goats.

This study investigated the antioxidant effect of quercetin-treated semen on frozen-thawed spermatozoa quality and in-vivo fertility in crossbred Kamori goats. In total, 32 ejaculates from four fertile bucks were diluted in Tris-based egg yolk extender with varying levels of quercetin (0, 1, 5, 10, and 15 μM). Qualified semen samples were pooled and frozen in French straws. The results revealed that the addition of quercetin in the semen extender increased (p < 0.05) frozen-thawed sperm total motility (TM), progressive motility (PM), rapid velocity (RV), average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), and amplitude of lateral head (ALH) displacement in contrast to the control group. Quercetin supplementation had no effect on beat cross frequency (BCF), straightness (STR), and linearity (LIN) (p > 0.05). Quercetin showed significantly higher (p < 0.05) plasma membrane and acrosome integrity and viability (p < 0.05) of spermatozoa in contrast to the control group. Quercetin in the semen extender significantly increased (p < 0.05) superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and total antioxidant capacity (TAC) levels while reduced (p < 0.05) the contents of total oxidant status (TOS) and malondialdehyde (MDA), which were in contrast to the control group. Ultrasound results revealed that 24 out of 30 (80%) goats were found pregnant when semen was treated with 5 μM quercetin while the control group showed 18 out of 30 (60%) animals were pregnant. Thus, the study concluded that 5 μM quercetin-treated semen was found to be efficient, showed increased antioxidant status, and reduced oxidant production, leading to improved spermatozoa quality and in-vivo fertility in goats.

Quercetin decreases fructose drinking in model of fructose-induced insulin resistance. Unexpected uric acid and TBARS lowering effect of methyl cellulose vehicle and fructose combination.

The aim of this study was to improve insulin sensitivity in fructose-treated animals by ingestion of flavonoid quercetin. Several signs of insulin resistance have been developed in rats by drinking 10% fructose solution for 9 weeks. The effect of 6-week-gavage-administrated quercetin (20 mg/kg/day in 1% methyl cellulose solution) was monitored. Rats of the control groups received methyl cellulose vehicle as well. The most striking result of the quercetin treatment was the normalization of the fructose solution drinking to the level of drinking water intake. In addition, quercetin supplementation considerably decreased the plasma glucose and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) index in rats consuming fructose. Surprisingly, fructose ingestion did not elevate plasma uric acid, thiobarbituric acid reactive substances, nitrotyrosine, or advanced glycation end products fluorescence. Instead, a reduction of the above parameters was observed. In summary, these results indicate that quercetin supplementation reduces fructose drinking and decreases plasma glucose and the HOMA-IR index. Furthermore, methyl cellulose, in combination with fructose, causes uric acid - lowering, antioxidant and anti-glycation effects. Thus, methyl cellulose possibly shifts fructose metabolism in favor of the utilization of antioxidant features of fructose. Our results call for using methyl cellulose in sweetened beverages and other sweetened food.

Quercetin: Exploring Its Unique Flavonol Properties, Bioavailability, Safety Profile, and Therapeutic Potential in High-Impact Medical Conditions

Quercetin, an abundant flavonoid in various foods and plants, exhibits diverse therapeutic potential due to its antioxidant, anti-inflammatory, and anticancer properties. This review explores its biological and pharmacological activities, mechanisms of action, formulations, absorption, bioavailability, adverse effects, and potential therapeutic applications.Initially isolated in the 1800s as a dye and in 1936 as a polyphenol, quercetin has garnered attention for its antioxidant capabilities, particularly in preventing oxidative damage from low-density lipoprotein (LDL) cholesterol, reducing the risk of cardiovascular disease (CVD). Studies also suggest its efficacy in lowering blood glucose levels, improving insulin sensitivity, and inhibiting viral infections, including COVID-19.Despite its promising benefits, quercetin’s bioavailability is limited by factors such as poor water solubility and rapid metabolism. Researchers have explored various formulations and delivery systems, including quercetin glycosides, nano-formulations, and phytosomes, to enhance quercetin’s absorption and effectiveness.While generally considered safe, high doses of quercetin supplements may lead to gastrointestinal disturbances, headache, and tingling sensation. Furthermore, its interaction with other medications warrants further investigation.Quercetin has therapeutic advantages in CVDs, metabolic syndrome, neurodegenerative disorders, respiratory conditions, skeletal conditions, bacterial and fungal infections, cancer, diabetes, iron-induced toxicity, oxidative stress, and viral infections. However, research in humans is limited, and optimal dosage and formulations remain to be established.Quercetin’s diverse pharmacological activities make it a promising therapeutic agent for various conditions, disorders, and diseases. Future research should focus on standardizing formulations, investigating long-term safety, elucidating mechanisms of action, and clarifying interactions with other medications to optimize quercetin’s therapeutic use.

Dietary supplementation with calcitriol or quercetin improved eggshell and bone quality by modulating calcium metabolism

This study was aimed to investigate the effects of dietary calcitriol or quercetin supplementation on eggshell and bone quality of laying hens. In trial 1, 72 Hy-Line Brown layers (80-week-old) with weak-shelled strength (25 to 30 N) were assigned into 4 dietary treatments with 6 replicates of 3 birds and fed a basal diet (4% calcium level) or basal diets supplemented with 0.5% calcium, 5 μg/kg calcitriol or 500 mg/kg quercetin for 4 weeks. In trial 2, 360 Hy-Line Brown layers (60-week-old) were divided into 3 groups with 8 replicates of 15 birds: control group (basal diet), calcitriol group (basal diet + 5 μg/kg calcitriol), and quercetin group (basal diet + 500 mg/kg quercetin). This trial lasted for 12 weeks. The results showed that dietary calcitriol or quercetin improved eggshell quality in both trials (P < 0.05). In trial 2, compared with the control group, both calcitriol and quercetin supplementations improved femoral bone quality, calcium retention of hens and calcium content in uterine fluid at 18.5 h post-oviposition (PO) (P < 0.05), along with enhancing uterine morphology. Compared to the control group, supplemental calcitriol or quercetin up-regulated the relative mRNA expression levels of uterine transient receptor potential cation channel, subfamily V, member 6 (TRPV6) at 8.5 h PO and plasma membrane calcium-ATPase (PMCA), vitamin D receptor (VDR), estrogen receptor alpha (ERα) at 18.5 h PO (P < 0.05), but down-regulated the uterine caspase 3 (CASP3) relative mRNA expression level at 8.5 h PO (P < 0.05). Meanwhile, the femoral relative mRNA expression levels of tartrate-resistant acid phosphatase (TRAP) (up-regulated at 8.5 and 18.5 h PO) and alkaline phosphatase (ALP) (up-regulated at 8.5 h PO but down-regulated at 18.5 h PO) were also affected by calcitriol or quercetin supplementation (P < 0.05). Compared to the calcitriol, quercetin increased hen-day egg production and femoral medullary bone volume/bone tissue volume but reduced femoral stiffness (P < 0.05), which were accompanied by increased relative mRNA expression levels of uterine TRPV6, estrogen receptor beta (ERβ) at 18.5 h PO (P < 0.05). Overall, both dietary calcitriol and quercetin could improve eggshell and bone quality by modulating calcium metabolism of aged layers. Compared to calcitriol, dietary quercetin up-regulated the expression of uterine calcium transporters, without affecting eggshell quality.

Increased Sperm DNA Damage in Sprague-Dawley Rats Exposed to Dextromethorphan as an Antitussive

Introduction: Male reproductive functions have been observed to be negatively impacted by the antitussive dextromethorphan (DM). It was also discovered that DM has an impact on micronutrients (such as zinc, calcium, and selenium) which are crucial for both capacitation and the acrosome reaction, which can result in infertility. Using Sprague-Dawley rats as models, we investigated the effects of quercetin and rutin on DM-induced toxicity in males in relation to apoptotic protein markers. Methodology: For a period of 16 weeks, 80 male rats, weighing 150 ± 30 g, were utilized and split into four groups. Twenty animals were employed in each group. For a period of 16 weeks, Group B received 20 mg/kg, Group C received 40 mg/kg, and Group D received 80 mg/kg of DM. Group A acted as the control group and received 1 ml of distilled water (DW). Five randomly chosen animals from each group were put to sleep at the end of the DM treatment period, and their testes were taken out to measure DNA fragmentation using comet assay. To ascertain the pace of recovery, the animals were then split into three groups, E–G, and kept for a total of 16 weeks. Group G received 1 ml of DW, Group F was given rutin (25 mg/kg), and Group E was given quercetin (50 mg/kg). Results: Comparing DM-treated groups to control revealed a significant dose-dependent decrease in DNA fragmentation. When DM-treated and recovery-alone groups were contrasted with rutin and quercetin groups, an improvement in DNA was seen. Conclusion: Significant improvements in the parameters were observed when rutin and quercetin supplements were used, which may lessen the harmful effects of DM and enhance male fertility.

Ethanol-Induced Hepatic Ferroptosis Is Mediated by PERK-Dependent MAMs Formation: Preventive Role of Quercetin.

Iron deposition is frequently observed in alcoholic liver disease (ALD), which indicates a potential role of ferroptosis in its development. This study aims to explore the effects of quercetin on ferroptosis in ALD and elucidates the underlying mechanism involving the formation of mitochondria-associated endoplasmic reticulum membranes (MAMs) mediated by protein kinase RNA-like endoplasmic reticulum kinase (PERK). C57BL/6J mice are fed either a regular or an ethanol-containing liquid diet (with 28% energy form ethanol) with or without quercetin supplementation (100mgkg-1 BW) for 12 weeks. Ethanol feeding or treatment induced ferroptosis in mice and AML12 cells, which is associated with increased MAMs formation and PERK expression within MAMs. Quercetin attenuates these changes and protects against ethanol-induced liver injury. The antiferroptotic effect of quercetin is abolished by ferroptosis inducers, but mimicked by ferroptosis inhibitors and PERK knockdown. The study demonstrates that PERK structure, rather than its kinase activity (transfected with the K618A site mutation that inhibits kinase activity-ΔK plasmid or protein C terminal knockout-ΔC plasmid of PERK), mediates the enhanced MAMs formation and ferroptosis during the ethanol exposure. Quercetin ameliorates ethanol-induced liver injury by inhibiting ferroptosis via modulating PERK-dependent MAMs formation.

YÜKSEK FRUKTOZLA BESLENEN SIÇANLARDA QUERCETİN’İN PERİRENAL YAĞ DOKUSUNDAKİ ADİPONEKTİN VE REZİSTİN DÜZEYLERİNE ETKİSİ

Obesity is defined as the accumulation of adipose tissue to excess and to an extent that impairs both physical and psychosocial health and well-being. The increase in adipose tissue observed in obesity causes proinflammatory and anti-inflammatory cytokine imbalance. Accumulating evidence on quercetin, one of the antioxidants frequently used in obesity treatment, suggests that quercetin has significant anti-obesity and lipid-lowering effects simultaneously. We hypothesized that quercetin supplementation could improve obesity parameters and restore adipokine balance in obese mice. Sprague Dawley rats, 8-10 weeks of age, were divided into 4 groups, including a control group (C), high fructose (HF) group, quercetine (Q) group, and high fructose+quercetin (HF+Q) group. Fructose was administered to HF groups as a 20% solution in drinking water for 6 weeks. The rats in the Q groups were given 50 mg quercetin per kg BW by gavage for the next 4 weeks. The body weight, lee index, TG, HDL, fasting insülin, fasting glucose, and HOMA-IR were determined in rats. ADP and resistin levels were determined by ELISA assay from perirenal adipose tissue homogenates. We showed that quercetin acts to improve TG, fasting glucose and insulin resistance in high fructose-fed rats. In this study, we found no effect of quercetin on perirenal adipose tissue ADP and resistin levels. These results showed that high fructose could induce obesity in rats, while quercetin could favorably affect these parameters.

Maternal quercetin supplementation improved lipopolysaccharide-induced cognitive deficits and inflammatory response in a rat model of maternal immune activation

BackgroundThere is strong evidence that prenatal infection during a specific period of brain development increases the risk of neurodevelopmental disorders, partly through immune-inflammatory pathways. This suggests that anti-inflammatory agents could prevent these disorders by targeting the maternal inflammatory response. In the present study, we used a rat model of maternal immune activation (MIA) to examine whether maternal quercetin (QE) supplementation can alleviate behavioral deficits and inflammatory mediators in the prefrontal cortex (PFC) and hippocampus of adult male offspring. MethodsPregnant rats were supplemented with QE (50 mg/kg) or vehicle throughout pregnancy and injected with either lipopolysaccharide (0.5 mg/kg) or saline on gestational days 15/16. At postnatal day 60, we evaluated the offspring's behavior, hippocampal and prefrontal cortex glial density, pro-inflammatory gene expression, and neuronal survival. ResultsOur data showed that maternal QE supplementation can prevent working and recognition memory impairments in adult MIA offspring. This behavioral improvement correlates with the decrease in MIA-induced expression of pro-inflammatory genes, microglia, and astrocyte densities, without affecting neuronal survival, in both PFC and CA1 hippocampus areas. ConclusionTherefore, our study supports the potential preventive effect of QE on MIA-induced behavioral dysfunctions, at least in part, by suppressing the glial-mediated inflammatory response.

Retracted: Dietary Quercetin Supplementation Attenuates Diarrhea and Intestinal Damage by Regulating Gut Microbiota in Weanling Piglets.

[This retracts the article DOI: 10.1155/2021/6221012.].

Effects of quercetin and hydroxytyrosol supplementation in a high-fat diet on growth, lipid metabolism, and mitochondrial function in spotted seabass (Lateolabrax maculatus)

Endoplasmic reticulum (ER) stress and mitochondrial impairment commonly occur during the progression of fatty liver disease. There is a close connection and crosstalk between mitochondria and ER. The potential positive influence of mitigating ER stress (ERS) and mitochondrial damage in the context of preventing and treating fatty liver was explored in spotted seabass (Lateolabrax maculatus) as a susceptible model to fatty liver. A normal-fat diet (11% fat, NFD) and a high-fat diet (17% fat, HFD) were formulated and three additional diets were prepared by supplementation of quercetin (QUE) (0.1%), hydroxytyrosol (HT) (0.02%) or their combination (0.1% QUE + 0.02% HT) to the HFD (HFD + QUE HFD + HT and HFD + QUE + HT diets).Three replicate groups of fish (25 ± 0.02 g) were fed the test diets to visual satiety for 8 weeks. The results revealed the deterioration of growth, feed intake and feed utilization in HFD group compared to the NFD group whereas QUE and HT application improved their values and the optimum results were achieved for the HFD + QUE + HT group. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, and both serum and hepatic triglyceride (TG), total cholesterol (T-CHO) and non-esterified free fatty acids (NEFA) concentrations were enhanced in HFD group, and their values decreased by QUE and HT, particularly their combined supplementation. The results of oil red O staining exhibited a remarkable reduction in number of lipid droplets in the liver of fish from HFD + QUE + HT group compared to the HFD group. Whole-body and muscle fat contents and abdominal fat index decreased by QUE and HT application. Expression of lipid metabolism related genes (srebp-1c, fas, acc) were down-regulated by QUE and HT treatment. Co-supplementation of QUE and HT down-regulated the expression of ERS-related genes (grp78, chop, perk, atf6, ire1), improved ER ultrastructure, and enhanced the coupling between mitochondria and ER. Moreover, expression of genes associated with hepatic mitochondrial biogenesis (pgc1-α, pgc1-β, nrf1) and mitophagy (pink1, atg5, mul1) was up-regulated in HFD + QUE, HFD + HT and HFD + QUE + HT groups. These data suggest that combined supplementation of QUE and HT in HFD for spotted seabass can improve growth and feed utilization, reduce hepatic damage and fat accumulation, and alleviate HFD induced ERS and mitochondrial dysfunction.

Quercetin Supplementation has no Synergetic Effect with High-Intensity Interval Training in Ameliorate Lipid Profile in Male Diabetic Rats

Background: In diabetic patients, lipid profile (LP) management is crucial. Quercetin (QUE), as an antioxidant supplement, has received a great deal of attention in improving the LP. Objectives: The current study aimed to investigate the simultaneous effect of high-intensity interval training (HIIT) and QUE on LP in male diabetic rats. Methods: Fifty Wistar male rats were randomly assigned to healthy control (HC; n = 10), diabetic control (DC; n = 10), high-intensity interval training (HIIT; n = 10), quercetin supplement (QS; n = 10), high-intensity interval training and quercetin (HIIQ; n = 10). QUE was given (20 mg/kg/d) to the animals daily for six weeks. HIIT has performed five sessions per week for six weeks in 8-10 sets with 85 - 65% of the maximum oxygen consumption (VO2max) on the treadmill. Blood samples were taken directly from the animal’s heart 48 hours after the last training session, and high-density lipoprotein (HDL-C), low-density lipoproteins (LDL-C), triglycerides (TG) cholesterol (CHOL), and fasting blood glucose (FBS) were measured in the serum. To analyze the data, two-way analysis of variance (ANOVA) and Tukey's post hoc test were used. Results: There was no significant difference between HIIQ with HIIT, QS in LDH-C and LDL-C (P &gt; 0.05). Also, no significant difference was seen between HIIT, QS, and HIIQ in TG concentration after intervention (P &gt; 0.05). CHOL was significantly lower in HIIT than QS (P = 0.001), while there was no significant difference between the HIIQ with QS (P &gt; 0.05). Also, there was no significant difference between QS and HIIQ in FBS (P &gt; 0.05). Conclusions: It seems that high-intensity interval training and quercetin alone can be effective in improving lipid profile. However, quercetin does not have a synergetic effect with high-intensity interval training in ameliorating lipid profile in diabetic male rats.

Evaluation of the Effect of Zinc, Quercetin, Bromelain and Vitamin C on COVID-19 Patients

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a new strain of coronavirus. There are three phases of COVID-19: early infection stage, pulmonary stage and hyper-inflammation stage respectively. It is important to prevent lung or other organs injuries by preventing phase-II and phase-III via pharmacological or non-pharmacological treatments. This was a case series study done on twenty-two patients confirmed to be infected with SARS-CoV-2 and diagnosed with COVID-19. Patients in this study have been used quercetin 800 mg, bromelain 165 mg, zinc acetate 50 mg and ascorbic acid 1 g once daily as supplements for 3 to 5 days during SARS-CoV-2 infection. The aim of this study is to evaluate the safety and efficacy of quercetin, bromelain, zinc and ascorbic acid combination supplements on patients with COVID-19. The mean levels of WBC, ANC, ALC, AMC and AST were normal among all included patients before and after taking quercetin, bromelain, zinc and ascorbic acid supplements (P-value &gt;0.05). Quercetin 800 mg, bromelain 165 mg, zinc acetate 50 mg and ascorbic acid 1 g once daily supplements were safe for patients infected with SARS-CoV-2 and may prevent poor prognosis. Randomized clinical trials needed in the future to ensure the efficacy of quercetin, bromelain, zinc and vitamin C combination.

Quercetin Supplementation Alleviates Cadmium Induced Genotoxicity-Mediated Apoptosis in Caprine Testicular Cells.

Being a common environmental pollutant, cadmium causes detrimental health effects, including testicular injury. Herein, we document the ameliorative potential of quercetin, a potent antioxidant, against cadmium-induced geno-cytotoxicity and steroidogenic toxicity in goat testicular tissue. Cadmium induced different comet types (Type 0 - Type 4), indicating the varying degree of DNA-damage in testicular cells. The quantitative analysis at 50 and 100 µM cadmium concentration revealed the DNA damage with per cent tail DNA as 75.78 ± 1.49 and 94.65 ± 0.95, respectively, in comparison to the control group (8.87 ± 0.48) post 8h exposure duration. Cadmium caused a substantial decrease in the activity of key steroidogenic enzymes' (3β-HSD and 17β-HSD) along with reduction of testosterone level in testicular tissue. Furthermore, cadmium treatment induced various types of deformities in sperm, altered the Bax/Bcl-2 expression ratio in testicular tissue and thus suggesting the apoptosis-mediated death of testicular cells. Simultaneous quercetin supplementation, however, significantly (p < 0.05) averted the aforementioned cadmium-mediated damage in testicular tissue. Conclusively, the cadmium-induced DNA-damage and decrease in steroidogenic potential results in death of testicular cells via apoptosis, which was significantly counteracted by quercetin co-supplementation, and thus preventing the cadmium-mediated cytotoxicity of testicular cells.

150 The protective role of quercetin supplementation in bovine granulosa cells against thermal stress

150 The protective role of quercetin supplementation in bovine granulosa cells against thermal stress

The Effect of Aerobic Exercise and Quercetin Supplementation on Myostatin and Follistatin Levels in the Heart Tissue of Rats with Type 2 Diabetes

The Effect of Aerobic Exercise and Quercetin Supplementation on Myostatin and Follistatin Levels in the Heart Tissue of Rats with Type 2 Diabetes

Quercetin counteracts monosodium glutamate to mitigate immunosuppression in the thymus and spleen via redox-guided cellular signaling

BackgroundChronic inflammation brought on by oxidative stress can result in several immunopathologies. Natural compounds with antioxidant characteristics, like quercetin, have shown effectiveness in reducing oxidative damage and regulating the immune response. PurposeThe commonly used food additive monosodium glutamate (M) causes immunosuppression by disrupting redox equilibrium and inducing oxidative stress. The goal of this work is to examine the therapeutic potential of quercetin against immunotoxicity brought on by M, revealing the molecular route implicated in such immunopathology by targeting the thymus and spleen, to support the development of future anti-inflammatory and antioxidant therapies. Study Design and MethodsM-fed rats were employed as an immunotoxicity model and were supplemented with quercetin for four weeks. Hematological and biochemical parameters were measured; H&E staining, immunohistochemistry, flow cytometry, real-time quantitative PCR, and western blotting were performed. ResultsBased on the findings, TLR4 was activated by M to cause oxidative stress-mediated inflammation, which was alleviated by the supplementation of quercetin by modulating redox homeostasis to neutralize free radicals and suppress the inflammatory response. To prevent M-induced inflammation, quercetin demonstrated anti-inflammatory functions by blocking NF-kB activation, lowering the production of pro-inflammatory cytokines, and increasing the release of anti-inflammatory cytokines. By normalizing lipid profiles and lowering the potential risk of immunological deficiency caused by M, quercetin also improves lipid metabolism. Additionally, it has shown potential for modifying insulin levels, suggesting a possible function in controlling M-induced alteration in glucose metabolism. The addition of quercetin to M enhanced the immune response by improving immunoglobulin levels and CD4/CD8 expression in the thymus and spleen. Additionally, quercetin inhibited apoptosis by controlling mitochondrial caspase-mediated cellular signaling, suggesting that it may be able to halt cell death in M-fed rats. ConclusionThe results of this study first indicate that quercetin, via modulating redox-guided cellular signaling, has a promising role in reducing immune disturbances. This study illuminates the potential of quercetin as a safe, natural remedy for immunopathology caused by M, including thymic hypoplasia and/or splenomegaly, and paves the way for future anti-inflammatory and antioxidant supplements.

The potential synergistic action of quercetin and/or Pediococcus acidilactici on Nile tilapia, Oreochromis niloticus performance

An 84-day experimental trial was conducted to investigate the effects of dietary quercetin, Pediococcus acidilactici or combined on growth performance, intestinal digestive enzymes, feed utilization, bacterial counts, intestinal histo-morphometric indices, hemato-biochemical indices, and antioxidant responses in Nile tilapia, Oreochromis niloticus. Four isonitrogenous (30.34 g kg−1 of crude protein) and isocaloric (19.21 MJ kg−1 gross energy) diets were formulated from practical ingredients. The first diet was the control diet. The other three formulated diets were supplemented with 5 g quercetin (quer) kg−1 diet or P. acidilacticiat 2 × 109 CFU kg− 1 (probiotic; pro), and their mixture 5 g quercetin kg−1 + 2 × 109P. acidilactici (CFU kg− 1) (pro-quer). A total number of 300 healthy fingerlings (Initial average weight 4.51 ± 0.01 g) were randomly allocated into four groups (25 fish for each group in triplicates). The results showed that the best values of growth, feed efficiency, and feed conversion ratio (FCR) were recorded in fish fed diet containing pro-quer. The activity of endogenous enzymes including; amylase, lipase, trypsin, and chymotrypsin was substantially boosted (P < 0.05) by supplemental diets with quercetin, probiotic, and pro-quer. Furthermore, fish fed diet supplemented with pro-quer had greater villi width, villi height, goblet cells, absorption area, muscularis mucosa, and muscularis. The highest total intestinal and gut bacterial counts were detected in fish fed diet supplemental with probiotic. Diets supplemented with quercetin, probiotic, and pro-quer substantially improved hematological markers including hematocrit (Htc), hemoglobin (Hb), red blood cell (RBC), and white blood cell (WBC) counts. The fish given a pro-quer diet had the lowest significant (P < 0.05) ALT value, whereas that fed quercetin had the lowest AST value. Serum total protein, globulin, and albumin levels were higher (P < 0.05) in fish fed diets containing quercetin, probiotic, and pro-quer compared to the control diet, with the greatest levels found in those fed diet supplemented with quercetin. However, supplementation of quercetin, probiotic, and pro-quer, lowered the levels of cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride. The supplemental diets with quercetin, probiotic, and pro-quer improved the activities of catalase (CAT), glutathione peroxidase (Gpx), superoxide dismutase (SOD), and total antioxidant capacity (TAC) compared with the control diet. In conclusion, the synergetic effect between quercetin and probiotic ameliorated the growth, feed efficiency, intestinal digestive enzymes, intestinal histological morphometric, hemato-biochemical indices, and antioxidant responses of Nile tilapia.

Quercetin improved hepatic circadian rhythm dysfunction in middle-aged mice fed with vitamin D-deficient diet.

We aimed to determine whether quercetin is capable of improving circadian rhythm and metabolism disorder under vitamin D-deficient condition. Middle-aged mice were randomly divided into four groups, namely, control (CON), vitamin D-deficient diet (VDD), quercetin (Q), and quercetin intervention in vitamin D-deficient diet (VDQ), with a total of 12 weeks' intervention. Mice were sacrificed at zeitgeber time1 (ZT1) and ZT13 time points. At ZT1, circadian locomotor output cycle kaput (CLOCK) protein expression from VDD, Q, and VDQ groups; CRY1 from Q group; and CRY2 from VDD group were significantly lower compared to CON group. The mRNA expression of Sirt1, Bmal1, Clock, Cry1, and Cry2 in VDQ groups, also Bmal1, Clock, and Cry1 from Q group, were significantly decreased compared to CON group. At ZT13, compared to CON group, fasting insulin and homeostasis model assessment-insulin resistance (HOMA-IR) were higher in VDD group; BMAL1 was significantly increased, while CLOCK and CRY1 protein were significantly decreased from VDD group; CLOCK protein from VDQ group was significantly higher compared to CON, VDD, and Q groups, and also, BMAL1 protein expression from VDQ group was elevated compared to CON group. The mRNA expression of Bmal1, Clock, Per2, Cry1, and Cry2 in VDQ groups were significantly increased compared to CON groups. The mRNA expression of Bmal1 from VDQ group was decreased compared to both VDD and Q group. In conclusion, vitamin D-deficient diet resulted in a disordered liver circadian rhythm, and quercetin improved the hepatic circadian desynchronization. Quercetin supplementation might be effective for balancing circadian rhythm under vitamin D-deficient condition.

Abstract 13683: Deciphering the Effects of Quercetin on Blood Pressure: A Systematic Review and Meta-Analysis

Introduction: Hypertension, a key driver of global cardiovascular diseases, has prompted interest in nutritional solutions like dietary supplements for managing blood pressure. The flavonoid quercetin, found in fruits and vegetables, has garnered attention for potential antihypertensive effects, although research on quercetin supplementation's impact on blood pressure has yielded varied outcomes. Hypothesis: This study aims to assess Quercetin supplementation's effects on blood pressure to comprehend its potential role in hypertension management. Methods: A systematic search was conducted across PubMed, Cochrane Library, Embase, and Scopus databases until December 2022 to include studies on the effects of Quercetin supplementation on blood pressure. The Mean Difference in Blood Pressure was used as the pooled effect size to compare the impact of Quercetin on patients, calculated with a random-effects model in R (version 4.0.3) using the metafor and meta packages. The I2 statistic was employed to evaluate heterogeneity. Results: The meta-analysis included ten studies with 743 participants, with 372 and 371 in the Quercetin and placebo/control groups, respectively. Quercetin supplementation in patients diagnosed with hypertension led to a statistically significant reduction in systolic blood pressure (MD: -3.19 mmHg; 95% CI: -4.41 to -1.99, P&lt;0.01, I2=73%). However, the reduction in diastolic blood pressure was not statistically significant (MD: -2.65 mmHg; 95% CI: -6.79 to 1.51, P=0.21, I2=98%). In individuals with normal blood pressure, quercetin supplementation resulted in a significant reduction in systolic blood pressure (MD: -2.97 mmHg; 95% CI: -4.72 to -1.22, P&lt;0.01, I2=74%), while its effect on diastolic blood pressure was not significant (MD: -2.99 mmHg; 95% CI: -10.18 to 4.21, P=0.42, I2=99%). Conclusions: The results indicate that quercetin supplementation notably lowers systolic blood pressure in hypertensive and normotensive individuals, but its impact on diastolic blood pressure is insignificant. These findings hint at Quercetin's potential as an auxiliary treatment for systolic hypertension, with a need for more high-quality, randomized controlled trials to determine its optimal dosage and duration.