scholarly journals Inhibition of Xanthine Oxidase-Catalyzed Xanthine and 6-Mercaptopurine Oxidation by Flavonoid Aglycones and Some of Their Conjugates

2020 ◽  
Vol 21 (9) ◽  
pp. 3256
Author(s):  
Violetta Mohos ◽  
Eszter Fliszár-Nyúl ◽  
Miklós Poór
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Positive Control ◽  
Acid Formation ◽  
Limited Information ◽  
Inhibitory Effects ◽  
Flavonoid Aglycones ◽  
Natural Phenolic Compounds ◽  
The Impact

Flavonoids are natural phenolic compounds, which are the active ingredients in several dietary supplements. It is well-known that some flavonoid aglycones are potent inhibitors of the xanthine oxidase (XO)-catalyzed uric acid formation in vitro. However, the effects of conjugated flavonoid metabolites are poorly characterized. Furthermore, the inhibition of XO-catalyzed 6-mercaptopurine oxidation is an important reaction in the pharmacokinetics of this antitumor drug. The inhibitory effects of some compounds on xanthine vs. 6-mercaptopurine oxidation showed large differences. Nevertheless, we have only limited information regarding the impact of flavonoids on 6-mercaptopurine oxidation. In this study, we examined the interactions of flavonoid aglycones and some of their conjugates with XO-catalyzed xanthine and 6-mercaptopurine oxidation in vitro. Diosmetin was the strongest inhibitor of uric acid formation, while apigenin showed the highest effect on 6-thiouric acid production. Kaempferol, fisetin, geraldol, luteolin, diosmetin, and chrysoeriol proved to be similarly strong inhibitors of xanthine and 6-mercaptopurine oxidation. While apigenin, chrysin, and chrysin-7-sulfate were more potent inhibitors of 6-mercaptopurine than xanthine oxidation. Many flavonoids showed similar or stronger (even 5- to 40-fold) inhibition of XO than the positive control allopurinol. Based on these observations, the extremely high intake of flavonoids may interfere with the elimination of 6-mercaptopurine.

scholarly journals Interactions of 7,8-Dihydroxyflavone with Serum Albumin as well as with CYP2C9, CYP2C19, CYP3A4, and Xanthine Oxidase Biotransformation Enzymes

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 655 ◽  
Author(s):  
Fliszár-Nyúl ◽  
Mohos ◽  
Bencsik ◽  
Lemli ◽  
Kunsági-Máté ◽  
...  
Keyword(s):  
Serum Albumin ◽  
Xanthine Oxidase ◽  
In Vitro Models ◽  
Stable Complex ◽  
Limited Information ◽  
Inhibitory Effects ◽  
Beneficial Effects ◽  
Biotransformation Enzymes ◽  
Pharmacokinetic Properties

7,8-dihydroxyflavone (DHF) is a flavone aglycone which has beneficial effects in several central nervous system diseases. Most of the pharmacokinetic properties of DHF have been characterized, while only limited information is available regarding its interactions with serum albumin and biotransformation enzymes. In this study, the interactions of DHF with albumin was examined employing fluorescence spectroscopy and ultrafiltration. Furthermore, the inhibitory effects of DHF on cytochrome P450 (CYP2C9, CYP2C19, and CYP3A4) and xanthine oxidase (XO) enzymes were also tested using in vitro models. Our results demonstrate that DHF forms a stable complex with albumin (K = 4.9 × 105 L/mol) and that it is able to displace both Site I and Site II ligands. Moreover, DHF proved to be a potent inhibitor of each enzyme tested, showing similar or slightly weaker effects than the positive controls used. Considering the above-listed observations, the coadministration of DHF with drugs may interfere with the drug therapy due to the development of pharmacokinetic interactions.

scholarly journals In vitro Xanthine Oxidase Inhibitory Studies of Lippia nodiflora and Isolated Flavonoids and Phenylethanoid Glycosides as Potential Uric Acid-lowering Agents

2015 ◽  
Vol 10 (6) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Lee-Chuen Cheng ◽  
Vikneswaran Murugaiyah ◽  
Kit-Lam Chan
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Metabolic Disorders ◽  
Methanolic Extract ◽  
Chemical Constituents ◽  
Positive Control ◽  
Phenylethanoid Glycosides ◽  
Whole Plant ◽  
Effective Use

Lippia nodiflora has been traditionally used for treatment of knee joint pain. Hitherto, no studies have been reported on the effective use of L. nodiflora against hyperuricemia, gout or other metabolic disorders. In this present study, L. nodiflora was examined for its ability to lower uric acid levels using an in vitro xanthine oxidase inhibitory assay. The whole plant methanolic extract was subjected to bioactivity-guided fractionation to yield 4 fractions (F1–F4). F3 displayed the highest potency and was further purified by column chromatography to afford two phenylethanoid glycosides, arenarioside (1) and verbascoside (2), and three flavonoids, 6-hydroxyluteolin (3), 6-hydroxyluteolin-7- O-glycoside (4), and nodifloretin (5). These compounds inhibited xanthine oxidase activity, with IC50 values between 7.52 ± 0.01 and 130.00 ± 2.25 μM, of which 3 was the most potent. In contrast, allopurinol, serving as a positive control, was 0.22 ± 0.00 μM. Thus, L. nodiflora, and its chemical constituents are worthy of further studies as potential anti-hyperuricemic agents.

Inhibitory effects of bioaccessible anthocyanins and procyanidins from apple, red grape, cinnamon on α-amylase, α-glucosidase and lipase

2020 ◽  
pp. 1-9
Author(s):  
Pınar Ercan ◽  
Sedef Nehir El
Keyword(s):  
Inhibitory Activity ◽  
Digestive Enzymes ◽  
Positive Control ◽  
Anthocyanin Content ◽  
Inhibitory Effects ◽  
Total Anthocyanin ◽  
Total Anthocyanin Content ◽  
Before And After ◽  
Red Grape

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.

scholarly journals Aktivitas Penghambatan Xantin Oksidase pada Ekstrak Daun Sirih Hitam (Piper sp)

2016 ◽  
Vol 3 ◽  
pp. 160-163
Author(s):  
Muhammad Amir Masruhim ◽  
Wisnu Cahyo Prabowo ◽  
Dita Paramitha
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Inhibitory Activity ◽  
Ethanol Extract ◽  
Betel Leaf ◽  
Activity Test ◽  
Ic50 Values ◽  
One Way Anova

Hyperuricemia is a condition in which increased levels of uric acid in the blood. Xanthine oxidase role in the oxidation of hypoxanthine and xanthine to uric acid. One treatment of hyperuricemia is inhibiting xanthine oxidase in the process of formation of uric acid. The purpose of this study to determine the inhibitory activity of xanthine oxidase in the ethanol extract of black betel leaf (Piper sp). Xanthine oxidase inhibitory activity test using UV-Vis spectrophotometry in vitro with a concentration of 5 ppm, 10 ppm and 20 ppm. The data obtained were analyzed using one-way ANOVA. The result is the ethanol extract of black betel leaf has a different activity significantly and IC50 values obtained is 65.96 ppm.

The Impact of Two Embryo Culture Media, SOF and Commercial BO, on Pre- and Post-Implantation Development of Cloned Sannen Goat Embryos

2020 ◽  
Author(s):  
Mehdi Hajian ◽  
Farnoosh Jafarpour ◽  
Sayed Morteza Aghamiri ◽  
Shiva Rouhollahi Varnosfaderani ◽  
Mohsen Rahimi ◽  
...  
Keyword(s):  
Embryo Culture ◽  
Culture Media ◽  
Specific Gene ◽  
Limited Information ◽  
Major Drawback ◽  
Animal Cloning ◽  
The Impact ◽  
Post Implantation

Abstract Background: The ingredients of embryo culture media developed by different companies are disclosed. Thus, it is impossible to determine which ingredients might be responsible for differences in pre-and post-implantation embryo development. To address this gap, we performed an experiment to compare two embryo culture media, namely, SOF and commercial BO, on pre- and post-implantation development of cloned Sannen goat embryos. Cumulus oocyte complexes derived from slaughterhouse ovaries were used for in vitro embryo production . In vitro development of IVF, parthenogenetic and SCNT embryos were assessed in both BO and SOF media. The expression of 16 genes, including AKT , OCT4 , SOX2 , BMPR1 , FGFR4 , CDC25 , CDX2 , GCN5 , PCAF , FOXD3 , SMAD5 , FZD , LIFR1 , CTNNB , ERK1 , and IFNT , belonging to 7 important pathways, i.e. pluripotency, FGF, TGFβ, cell cycle and proliferation, histone transferase, trophectoderm, and WNT, were examined in the goat SCNT and IVF blastocysts from both BO and SOF media. Results: The blastocyst rate in BO medium was significantly higher than that of the SOF medium in SCNT embryos ( P < 0.05). All of the genes examined showed increased expression levels in SCNT embryos compared to IVF embryos. In the IVF group, OCT4 , BMPR1 , and GCN5 showed significantly higher expression in the SOF medium compared to the BO medium. In this group, AKT , FGFR4 , SOX2 showed significantly lower expression in the SOF medium compared to the BO medium. In the SCNT group, FGFR4 , GCN5 , FZD , CTNNB , BMPR1 , and FGFR4 showed significantly higher expression in SOF medium compared to BO medium. In vivo development did not differ significantly between the two groups. Conclusions: Based on these results, we concluded that the limited information available on the allocations of ICM and TE cells in SCNT embryos and embryo-specific gene expression may be the major drawback IVC medium and an impediment to successful animal cloning.

scholarly journals Xanthine oxidase inhibition protects against Western diet-induced aortic stiffness and impaired vasorelaxation in female mice

2017 ◽  
Vol 313 (2) ◽  
pp. R67-R77 ◽  
Author(s):  
Guido Lastra ◽  
Camila Manrique ◽  
Guanghong Jia ◽  
Annayya R. Aroor ◽  
Melvin R. Hayden ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Arterial Stiffness ◽  
Xanthine Oxidase ◽  
Aortic Stiffness ◽  
Plasma Concentrations ◽  
Western Diet ◽  
Vascular Stiffness ◽  
High Fructose ◽  
The Impact

Consumption of a high-fat, high-fructose diet [Western diet (WD)] promotes vascular stiffness, a critical factor in the development of cardiovascular disease (CVD). Obese and diabetic women exhibit greater arterial stiffness than men, which contributes to the increased incidence of CVD in these women. Furthermore, high-fructose diets result in elevated plasma concentrations of uric acid via xanthine oxidase (XO) activation, and uric acid elevation is also associated with increased vascular stiffness. However, the mechanisms by which increased xanthine oxidase activity and uric acid contribute to vascular stiffness in obese females remain to be fully uncovered. Accordingly, we examined the impact of XO inhibition on endothelial function and vascular stiffness in female C57BL/6J mice fed a WD or regular chow for 16 wk. WD feeding resulted in increased arterial stiffness, measured by atomic force microscopy in aortic explants (16.19 ± 1.72 vs. 5.21 ± 0.54 kPa, P < 0.05), as well as abnormal aortic endothelium-dependent and -independent vasorelaxation. XO inhibition with allopurinol (widely utilized in the clinical setting) substantially improved vascular relaxation and attenuated stiffness (16.9 ± 0.50 vs. 3.44 ± 0.50 kPa, P < 0.05) while simultaneously lowering serum uric acid levels (0.55 ± 0.98 vs. 0.21 ± 0.04 mg/dL, P < 0.05). In addition, allopurinol improved WD-induced markers of fibrosis and oxidative stress in aortic tissue, as analyzed by immunohistochemistry and transmission electronic microscopy. Collectively, these results demonstrate that XO inhibition protects against WD-induced vascular oxidative stress, fibrosis, impaired vasorelaxation, and aortic stiffness in females. Furthermore, excessive oxidative stress resulting from XO activation appears to play a key role in mediating vascular dysfunction induced by chronic exposure to WD consumption in females.

scholarly journals LOWERING URIC ACID EFFICACY TEST OF THE COMBINED EXTRACT OF UNCARIA GAMBIR (HUNTER) ROXB. AND CAESALPINIA SAPPAN L. IN VIVO AND IN VITRO

2018 ◽  
Vol 11 (8) ◽  
pp. 166
Author(s):  
Sri Ningsih ◽  
Fahri Fahrudin
Keyword(s):  
Antioxidant Activity ◽  
Uric Acid ◽  
Inhibitory Activity ◽  
Positive Control ◽  
Polyphenol Content ◽  
Caesalpinia Sappan ◽  
In Vivo Experiments ◽  
A Value

 Objective: Hyperuricemia (high uric acid levels) prevalence increased year by year. This study was aimed to elaborate the in vitro xanthine oxidase (XO) inhibitory activity and in vivo lowering hyperuricemic effect of Uncaria gambir (Hunter) Roxb) (gambir), Caesalpinia sappan L. (secang) and the combined extract of secang and gambir (formulae extract [FE]).Methods: Gambir and secang extracts were prepared by maceration with ethanol and FE was the proportioned combination of these two extracts. XO inhibitory activity was determined by measuring the formation of uric acid in the xanthine/XO system in vitro using allopurinol as a positive control at 100 ug/mL. Antioxidant activity was by 1,1-diphenyl-2-picrylhydrazyl radical reducing methods. The in vivo experiments were conducted in the oxonate-induced hyperuricemia rat model, in which FE was gavaged p.o. at the arrange dose of 75, 150, and 300 mg/kg bw for 2 weeks. Polyphenol content was measured using Folin–Ciocalteu reagent spectrophotometrically.Results: The XO inhibitory activity of FE was 80% of allopurinol, while secang and gambir were 98% and 50%, respectively. The strength was appropriate to the total polyphenol content, in which it decreased in the order of secang (99%) > FE (86%) > gambir (46%). Furthermore, FE at all tested doses was able to decrease uric acid levels. FE also demonstrated antioxidant activity with a value of 74% relative to Vitamin C at 4 ug/mL.Conclusion: These studies could be concluded that FE exhibited the ability to decrease uric acid level so that it was potential to be developed further as a uric acid-lowering agent.

scholarly journals Inhibitory Effects of Quercetin and Its Human and Microbial Metabolites on Xanthine Oxidase Enzyme

2019 ◽  
Vol 20 (11) ◽  
pp. 2681 ◽  
Author(s):  
Violetta Mohos ◽  
Attila Pánovics ◽  
Eszter Fliszár-Nyúl ◽  
Gabriella Schilli ◽  
Csaba Hetényi ◽  
...  
Keyword(s):  
Drug Interactions ◽  
Xanthine Oxidase ◽  
Parent Compound ◽  
Inhibitory Effect ◽  
Positive Control ◽  
Microbial Metabolites ◽  
Inhibitory Effects ◽  
Potent Inhibition ◽  
Oxidase Enzyme ◽  
Few Data

Quercetin is an abundant flavonoid in nature and is used in several dietary supplements. Although quercetin is extensively metabolized by human enzymes and the colonic microflora, we have only few data regarding the pharmacokinetic interactions of its metabolites. Therefore, we investigated the interaction of human and microbial metabolites of quercetin with the xanthine oxidase enzyme. Inhibitory effects of five conjugates and 23 microbial metabolites were examined with 6-mercaptopurine and xanthine substrates (both at 5 μM), employing allopurinol as a positive control. Quercetin-3′-sulfate, isorhamnetin, tamarixetin, and pyrogallol proved to be strong inhibitors of xanthine oxidase. Sulfate and methyl conjugates were similarly strong inhibitors of both 6-mercaptopurine and xanthine oxidations (IC50 = 0.2–0.7 μM); however, pyrogallol inhibited xanthine oxidation (IC50 = 1.8 μM) with higher potency vs. 6-MP oxidation (IC50 = 10.1 μM). Sulfate and methyl conjugates were approximately ten-fold stronger inhibitors (IC50 = 0.2–0.6 μM) of 6-mercaptopurine oxidation than allopurinol (IC50 = 7.0 μM), and induced more potent inhibition compared to quercetin (IC50 = 1.4 μM). These observations highlight that some quercetin metabolites can exert similar or even a stronger inhibitory effect on xanthine oxidase than the parent compound, which may lead to the development of quercetin–drug interactions (e.g., with 6-mercaptopurin or azathioprine).

Sign in / Sign up

Export Citation Format

Share Document