Epicatechin Gallate as Xanthine Oxidase Inhibitor: Inhibitory Kinetics, Binding Characteristics, Synergistic Inhibition, and Action Mechanism

Epicatechin gallate (ECG) is one of the main components of catechins and has multiple bioactivities. In this work, the inhibitory ability and molecular mechanism of ECG on XO were investigated systematically. ECG was determined as a mixed xanthine oxidase (XO) inhibitor with an IC50 value of 19.33 ± 0.45 μM. The promotion of reduced XO and the inhibition of the formation of uric acid by ECG led to a decrease in O2− radical. The stable ECG–XO complex was formed by hydrogen bonds and van der Waals forces, with the binding constant of the magnitude of 104 L mol−1, and ECG influenced the stability of the polypeptide skeleton and resulted in a more compact conformation of XO. Computational simulations further characterized the binding characteristics and revealed that the inhibitory mechanism of ECG on XO was likely that ECG bound to the vicinity of flavin adenine dinucleotide (FAD) and altered the conformation of XO, hindering the entry of substrate and the diffusion of catalytic products. ECG and allopurinol bound to different active sites of XO and exerted a synergistic inhibitory effect through enhancing their binding stability with XO and changing the target amino acid residues of XO. These findings may provide a theoretical basis for the further application of ECG in the fields of food nutrition and functional foods.

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Natural Xanthine Oxidase Inhibitor 5-O-Caffeoylshikimic Acid Ameliorates Kidney Injury Caused by Hyperuricemia in Mice

Molecules ◽

10.3390/molecules26237307 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7307

Author(s):

Dong Zhang ◽

Mojiao Zhao ◽

Yumei Li ◽

Dafang Zhang ◽

Yong Yang ◽

...

Keyword(s):

Xanthine Oxidase ◽

In Silico ◽

Active Sites ◽

Kidney Injury ◽

Oxidase Inhibitor ◽

Mice Model ◽

Xanthine Oxidase Inhibitor ◽

Sgr A

Xanthine oxidase (XOD) inhibition has long been considered an effective anti-hyperuricemia strategy. To identify effective natural XOD inhibitors with little side effects, we performed a XOD inhibitory assay-coupled isolation of compounds from Smilacis Glabrae Rhizoma (SGR), a traditional Chinese medicine frequently prescribed as anti-hyperuricemia agent for centuries. Through the in vitro XOD inhibitory assay, we obtained a novel XOD inhibitor, 5-O-caffeoylshikimic acid (#1, 5OCSA) with IC50 of 13.96 μM, as well as two known XOD inhibitors, quercetin (#3) and astilbin (#6). Meanwhile, we performed in silico molecular docking and found 5OCSA could interact with the active sites of XOD (PDB ID: 3NVY) with a binding energy of −8.6 kcal/mol, suggesting 5OCSA inhibits XOD by binding with its active site. To evaluate the in vivo effects on XOD, we generated a hyperuricemia mice model by intraperitoneal injection of potassium oxonate (300 mg/kg) and oral gavage of hypoxanthine (500 mg/kg) for 7 days. 5OCSA could inhibit both hepatic and serum XOD in vivo, together with an improvement of histological and multiple serological parameters in kidney injury and HUA. Collectively, our results suggested that 5OCSA may be developed into a safe and effective XOD inhibitor based on in vitro, in silico and in vivo evidence.

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Beneficial Effects of Xanthine Oxidase Inhibitor, Topiloxostat, on Experimental Diabetic Neuropathy in Mice

Diabetes ◽

10.2337/db18-549-p ◽

2018 ◽

Vol 67 (Supplement 1) ◽

pp. 549-P

Author(s):

HIROKI MIZUKAMI ◽

REMINA KOYAMA ◽

KAZUHISA TAKAHASHI ◽

SHO OSONOI ◽

SAORI OGASAWARA ◽

...

Keyword(s):

Diabetic Neuropathy ◽

Xanthine Oxidase ◽

Oxidase Inhibitor ◽

Xanthine Oxidase Inhibitor ◽

Beneficial Effects ◽

Experimental Diabetic Neuropathy

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Faculty Opinions recommendation of Xanthine oxidase inhibitor tungsten prevents the development of atherosclerosis in ApoE knockout mice fed a Western-type diet.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1046725.496732 ◽

2006 ◽

Author(s):

Klaus Ley

Keyword(s):

Xanthine Oxidase ◽

Knockout Mice ◽

Oxidase Inhibitor ◽

Xanthine Oxidase Inhibitor ◽

Apoe Knockout Mice

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Allopurinol and Loss of Consciousness in a 78-old Year Man Suffering from Gout

Infectious Disorders - Drug Targets ◽

10.2174/1871526519666190128102039 ◽

2020 ◽

Vol 20 (2) ◽

pp. 253-256 ◽

Cited By ~ 1

Author(s):

Mahnaz Arian ◽

Mina AkbariRad ◽

Ahmad Bagheri Moghaddam ◽

Abdollah Firoozi ◽

Mohammad Jami

Keyword(s):

Uric Acid ◽

Xanthine Oxidase ◽

Kidney Stones ◽

Oxidase Inhibitor ◽

Loss Of Consciousness ◽

Drug Induced ◽

Xanthine Oxidase Inhibitor ◽

Case Presentation ◽

Maculopapular Rashes ◽

Reduced State

: Allopurinol is an FDA -Approved xanthine oxidase inhibitor, which is effective in the treatment of gout, hyperuricemia and uremic kidney stones in patients with an increased level of uric acid excretion. Xanthine oxidase acts by converting hypoxanthine and xanthine into uric acid, and therefore its inhibition results in decreased production of uric acid. The most common side effects of this medication are as follows: maculopapular rashes, hives, itching, headache, dizziness, abnormal hair loss, fever and hypersensitivity reaction. Case Presentation: This report represents a case of drug-induced meningitis of a senile man who ended up in the ICU due to the remarkably reduced state of consciousness.

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Xanthine oxidase inhibitors are associated with reduced risk of cardiovascular disease

Scientific Reports ◽

10.1038/s41598-020-80835-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hirotaka Saito ◽

Kenichi Tanaka ◽

Tsuyoshi Iwasaki ◽

Akira Oda ◽

Shuhei Watanabe ◽

...

Keyword(s):

Cardiovascular Disease ◽

Chronic Kidney Disease ◽

Xanthine Oxidase ◽

Cardiovascular Events ◽

Oxidase Inhibitor ◽

Cardiovascular Risks ◽

Diabetic Mellitus ◽

Xanthine Oxidase Inhibitor ◽

Xanthine Oxidase Inhibitors ◽

Reduced Risk

AbstractAs previous studies have reported finding an association between hyperuricemia and the development of cardiovascular and chronic kidney disease, hyperuricemia is thought to be an independent risk factor for hypertension and diabetic mellitus. However, we have not been able to determine whether the use of xanthine oxidase inhibitors can reduce cardiovascular disease. The present study used the longitudinal data of the Fukushima Cohort Study to investigate the relationship between the use of xanthine oxidase inhibitors and cardiovascular events in patients with cardiovascular risks. During the 3-year period between 2012 and 2014, a total of 2724 subjects were enrolled in the study and followed. A total of 2501 subjects had hypertension, diabetic mellitus, dyslipidemia, or chronic kidney disease, and were identified as having cardiovascular risks. The effects of xanthine oxidase inhibitor use on the development of cardiovascular events was evaluated in these patients using a time to event analysis. During the observational periods (median 2.7 years), the incidence of cardiovascular events was 20.7 in subjects with xanthine oxidase inhibitor and 11.2 (/1000 person-years, respectively) in those without. Although a univariate Cox regression analysis showed that the risk of cardiovascular events was significantly higher in subjects administered xanthine oxidase inhibitors (HR = 1.87, 95% CI 1.19–2.94, p = 0.007), the risk was significantly lower in subjects administered a xanthine oxidase inhibitor after adjustment for covariates (HR = 0.48, 95% CI 0.26–0.91; p = 0.024) compared to those without. Xanthine oxidase inhibitor use was associated with reduced risk of cardiovascular disease in patients with cardiovascular risk factors.

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Effects of 6-formylpterin, a xanthine oxidase inhibitor and a superoxide scavenger, on production of nitric oxide in RAW 264.7 macrophages

Biochimica et Biophysica Acta (BBA) - General Subjects ◽

10.1016/s0304-4165(99)00210-x ◽

2000 ◽

Vol 1474 (1) ◽

pp. 93-99 ◽

Cited By ~ 7

Author(s):

H Mori

Keyword(s):

Nitric Oxide ◽

Xanthine Oxidase ◽

Oxidase Inhibitor ◽

Raw 264.7 ◽

Xanthine Oxidase Inhibitor ◽

Raw 264.7 Macrophages ◽

Superoxide Scavenger

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The xanthine oxidase inhibitor oxypurinol does not limit infarct size in a canine model of 40 minutes of ischemia with reperfusion

Journal of the American College of Cardiology ◽

10.1016/0735-1097(88)90376-2 ◽

1988 ◽

Vol 12 (1) ◽

pp. 209-217 ◽

Cited By ~ 21

Author(s):

James M Kinsman ◽

Charles E Murry ◽

Vincent J Richard ◽

Robert B Jennings ◽

Keith A Reimer

Keyword(s):

Infarct Size ◽

Xanthine Oxidase ◽

Canine Model ◽

Oxidase Inhibitor ◽

Xanthine Oxidase Inhibitor

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Fluorometric determination of uric acid in bovine milk

Journal of Dairy Research ◽

10.1017/s0022029910000580 ◽

2010 ◽

Vol 77 (4) ◽

pp. 438-444 ◽

Cited By ~ 17

Author(s):

Torben Larsen ◽

Kasey M Moyes

Keyword(s):

Heat Treatment ◽

Uric Acid ◽

Xanthine Oxidase ◽

Bovine Milk ◽

Oxidase Inhibitor ◽

Enzymatic Oxidation ◽

Fast Method ◽

Xanthine Oxidase Inhibitor ◽

Milk Samples

The primary objective of this study is to validate a new fast method for determination of uric acid in milk. The method is based on an enzymatic-fluorometric technique that requires minimal pre-treatment of milk samples. The present determination of uric acid is based on the enzymatic oxidation of uric acid to 5-hydroxyisourate via uricase where the liberated hydrogen peroxide reacts with 10-acetyl-3,7-dihydroxyphenoxazine via peroxidase and the fluorescent product, resorufin, is measured fluorometrically. Fresh composite milk samples (n=1,072) were collected from both Jersey (n=38) and Danish Holstein (n=106) cows from one local herd. The average inter- and intra-assay variations were 7·1% and 3·0%, respectively. Percent recovery averaged 103·4, 107·0 and 107·5% for samples spiked with 20, 40 or 60 μmof standard, respectively, with a correlation (r=0·98;P<0·001) observed between the observed and expected uric acid concentrations. A positive correlation (r=0·96;P<0·001) was observed between uric acid concentrations using the present method and a reference assay. Storage at 4°C for 24 h resulted in lower (P<0·01) uric acid concentrations in milk when compared with no storage or samples stored at −18°C for 24 h. Addition of either allopurinol (a xanthine oxidase inhibitor) or dimethylsulfoxide (a solvent for allopurinol) did not affect milk uric acid concentrations (P=0·96) and may indicate that heat treatment before storage and analysis was sufficient to degrade xanthine oxidase activity in milk. No relationship was observed between milk uric acid and milk yield and milk components. Authors recommend a single heat treatment (82°C for 10 min) followed by either an immediate analysis of fresh milk samples or storage at −18°C until further analysis.

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