Xanthine Oxidase Inhibitory Activity Research Articles

Protective Effect of Ferulic Acid on Acetylcholinesterase and Amyloid Beta Peptide Plaque Formation in Alzheimer's Disease: An In Vitro Study.

Aim This study aims to comprehensively evaluate the effects of ferulic acid (FA) on acetylcholinesterase (AChE) enzyme activity and amyloid beta (Aβ) peptide plaque formation in an in vitro model of Alzheimer's disease (AD). Background ADis a progressive neurological condition marked by disrupted cholinergic signaling, accumulation of Aβ peptide, and tau protein hyperphosphorylation. Currently, no direct anti-Alzheimer drug that effectively prevents the cognitive decline from AD has been reported. To combat this, a multi-target drug addressing several molecular aspects would be ideal for AD. Natural compounds are preferred over synthetic drugs due to their accessibility, cost-efficiency, and lower toxicity The proven association between polyphenolconsumption and the prevention of AD has led to the investigation of the effect of FA, a polyphenolic compound, on acetylcholinesterase enzyme activity and Aβ peptide formation, the key targets of AD. Materials and method The free radical scavenging ability of FA was assessed by xanthine oxidase inhibitory activity. Furthermore, FA was also evaluated for its inhibitory activity against AChE enzyme and amyloid beta peptide formation to evaluate the neuroprotective potential of FA. Results The results showed that FA has the potential to be an AChE inhibitor, thus helping in blocking the activity of AChE and also reducing the incidence of amyloid beta plaque formation. Furthermore, the compound also exhibited a significant antioxidant property which was demonstrated by the xanthine oxidase enzyme inhibitory effect. Conclusion From the observed results, FA has significant antioxidant and neuroprotective effects which are compared with those of their respective standards. More research is required to determine the efficacy and safety of this compound as a treatment for neurodegenerative diseases like AD because the precise mechanism and degree of its AChE inhibitory effects in the brain are still elusive. A potent, selective, and effective drug is desperately needed to treat patients with AD and those at risk of developing the disease.

Anti-Hyperuricemic Effects of Extracts from Chaenomeles speciosa (Sweet) Nakai Fruits on Hyperuricemic Rats.

Chaenomeles speciosa (Sweet) Nakai (C. speciosa) fruit has medicinal and food applications and exhibits beneficial pharmacological properties. This study aimed to explore the hypouricemic effect of C. speciosa fruit extracts on hyperuricemic rats and uncover potential protective mechanisms. The rats were given hypoxanthine (HX, 100 mg/kg) and potassium oxonate (PO, 300 mg/kg) for 14 days to induce hyperuricemia. Subsequently, the rats were orally administered C. speciosa fruits total extract (CSFTE, 250, 500, and 1000 mg/kg) and allopurinol (AP, 10 mg/kg) one hour after exposure to HX and PO. The results showed that CSFTE had significant xanthine oxidase (XOD) inhibitory activity in vitro (IC50 value of 334.2 μg/mL) and exhibited hypouricemic effects in vivo, reducing uric acid (UA), creatinine (CRE), and blood urea nitrogen (BUN) levels in serum. CSFTE increased UA excretion through the regulation of URAT1, GLUT9, OAT1, and OAT3 protein expression in the kidneys of hyperuricemic rats. Additionally, CSFTE (500 and 1000 mg/kg) was more effective than AP in improving renal injury and protecting kidney function in hyperuricemic rats. Our study demonstrated that CSFTE effectively reduced UA levels and protected the kidneys by inhibiting XOD expression in vitro and regulating UA, CRE, BUN, URAT1, GLUT9, OAT1, and OAT3 proteins in vivo.

Metabolomics Profiles of Solid State and Submerge Fermentation of Corn Silk using Mixed Microbes

Corn silk is a waste product when harvesting corn, but it contains many bioactive compounds. This research characterized and assessed the antioxidant bioactivity of compounds isolated from corn silk. Two different biological fermentation processes were compared: Solid-state fermentation (SSF) and submerged fermentation (SmF). Fresh corn silk (Zea mays L.) from both sweet corn and feed corn were fermented separately with various microorganisms (Bacillus subtilis, Lactobacillus sp. and Saccharomyces cerevisiae). Biological compounds were identified using LC-MS/MS. The extract was then tested for total phenolic content (TPC) and total flavonoid content (TFC). Next, the extract was tested for xanthine oxidase inhibition and antioxidant inhibition using the ABTS method. Potential contamination with the heavy metals As, Pb, and Hg was checked. The results show that fermented corn silk extract contains numerous bioactive compounds and amino acids. Among the different extract process variations, the highest TPC and TFC were 6.1 ± 0.7 µg GAE/g dry wt. and 68.3 ± 1.1 µg QE/g dry wt., respectively, and the highest xanthine oxidase inhibition was 76.5 ± 6.4 %. The above highest results were obtained using SmF of sweet corn for 60 days. In contrast, the highest antioxidant activity of 66.9 % was found using SSF of sweet corn for 20 days. Neither sweet corn nor feed corn were found to contain heavy metal ions. In summary, fermented corn silk extract samples contain numerous bioactive compounds, including both flavonoid and phenolic compounds, and the extract demonstrates antioxidant activity. Corn silk extracts from fermentation thus have potential for utilization in health products. HIGHLIGHTS Feed corn silk and sweet corn silk underwent solid-state fermentation (SSF) or submerged fermentation (SmF) for extraction using heterofermentative microbes of Bacillus subtilis, Lactobacillus and Saccharomyces cerevisiae to produce the high bioactive compounds, amino acids, and organic acids Metabolomic analysis of the fermentation extracts was carried out by LC-ESI-QTOF-MS/MS (Liquid Chromatography-Mass Spectrometry) using the heatmaps generated metabolites profiles The main amino acids found in the extractions were phenylalanine, leucine, and their derivatives SmF of sweet corn silk yielded the highest xanthine oxidase inhibitory activity (76 %) SSF of feed corn silk and sweet corn silk displayed the high antioxidant activity GRAPHICAL ABSTRACT

Comparative Assessment of In Vitro Xanthine Oxidase and α-Glucosidase Inhibitory Activities of Cultured Cambial Meristematic Cells, Adventitious Roots, and Field-Cultivated Ginseng.

Panax ginseng, a traditional Chinese medicine with a history spanning thousands of years, faces overexploitation and challenges related to extended growth periods. Tissue-cultured adventitious roots and stem cells are alternatives to wild and field-cultivated ginseng. In this study, we assessed the in vitro xanthine oxidase and α-glucosidase inhibitory activities of saponin extracts among cultured cambial meristematic cells (CMC), adventitious ginseng roots (AGR), and field-cultivated ginseng roots (CGR). The xanthine oxidase (XO) and α-glucosidase inhibitory activities were determined by uric acid estimation and the p-NPG method, respectively. Spectrophotometry and the Folin-Ciocalteu, aluminum nitrate, and Bradford methods were employed to ascertain the total saponins and phenolic, flavonoid, and protein contents. The calculated IC50 values for total saponin extracts against XO and α-glucosidase were 0.665, 0.844, and >1.6 mg/mL and 0.332, 0.745, and 0.042 mg/mL for AGR, CMC, CGR, respectively. Comparing the total saponin, crude protein, and total phenolic contents revealed that AGR > CMC > CGR. To the best of our knowledge, this study presents the first report on the in vitro comparison of xanthine oxidase and α-glucosidase inhibitory activities among AGR, CMC, and CGR. The findings offer valuable insights into the development of hypoglycemic and antihyperuricemic medicinal, nutraceutical, and functional products utilizing AGR and CMC.

Improving the thermostability of Pseudoalteromonas Porphyrae κ-carrageenase by rational design and MD simulation

The industrial applications of the κ-carrageenases have been restricted by their poor thermostability. In this study, based on the folding free energy change (ΔΔG) and the flexibility analysis using molecular dynamics (MD) simulation for the alkaline κ-carrageenase KCgCD from Pseudoalteromonas porphyrae (WT), the mutant S190R was identified with improved thermostability. After incubation at 50 °C for 30 min, the residual activity of S190R was 63.7%, 25.7% higher than that of WT. The Tm values determined by differential scanning calorimetry were 66.2 °C and 64.4 °C for S190R and WT, respectively. The optimal temperature of S190R was 10 °C higher than that of WT. The κ-carrageenan hydrolysates produced by S190R showed higher xanthine oxidase inhibitory activity compared with the untreated κ-carrageenan. MD simulation analysis of S190R showed that the residues (V186–M194 and P196–G197) in F5 and the key residue R150 in F3 displayed the decreased flexibility, and residues of T169–N173 near the catalytic center displayed the increased flexibility. These changed flexibilities might be the reasons for the improved thermostability of mutant S190R. This study provides a useful rational design strategy of combination of ΔΔG calculation and MD simulation to improve the κ-carrageenase’s thermostability for its better industrial applications.

Synthesis, structural characterizations, in vitro biological evaluation and computational investigations of pyrazole derivatives as potential antidiabetic and antioxidant agents

In this study, a two pyrazole derivatives; 2-(5-methyl-1H-pyrazole-3-carbonyl)-N-phenylhydrazine-1-carboxamide (Pyz-1) and 4-amino-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol (Pyz-2) were synthesized and characterized by 13C-NMR, 1H-NMR, FT-IR, and mass spectrometry. A complete molecular structures optimization, electronic and thermodynamic properties of Pyz-1 and Pyz-2 in gas phase and aqueous solution were predicted by using hybrid B3LYP method with the 6-311++G** basis sets. Pyz-1 and Pyz-2 were evaluated in vitro for their anti-diabetic, antioxidant and xanthine oxidase inhibition activities. For anti-diabetic activity, Pyz-1 and Pyz-2 showed a potent α-glucosidase and α-amylase inhibition with IC50 values of 75.62 ± 0.56, 95.85 ± 0.92 and 119.3 ± 0.75, 120.2 ± 0.68 µM, respectively, compared to Acarbose (IC50(α-glucosidase) = 72.58 ± 0.68 µM, IC50(α-amylase) = 115.6 ± 0.574 µM). In xanthine oxidase assay, Pyz-1 and Pyz-2 exhibited remarkable inhibitory ability with IC50 values 24.32 ± 0.78 and 10.75 ± 0.54 µM, respectively. The result of antioxidant activities showed that the title compounds have considerable antioxidant and radical scavenger abilities. In addition, molecular docking simulation was used to determine the binding modes and energies between the title compounds and α-glucosidase and α-amylase enzymes.

A strategy to boost xanthine oxidase and angiotensin converting enzyme inhibitory activities of peptides via molecular docking and module substitution

Molecular docking and activity evaluation screened the dipeptide module GP with low xanthine oxidase (XOD) inhibitory activity and modules KE and KN with high activity, and identified them as low- and high-contribution modules, respectively. We hypothesized the substitution of low-contribution modules in peptides with high contributions would boost their XOD inhibitory activity. In the XOD inhibitory peptide GPAGPR, substitution of GP with both KE and KN led to enhanced affinity between the peptides and XOD. They also increased XOD inhibitory activity (26.4% and 10.3%) and decreased cellular uric acid concentrations (28.0% and 10.4%). RNA sequencing indicated that these improvements were attributable to the inhibition of uric acid biosynthesis. In addition, module substitution increased the angiotensin-converting enzyme inhibitory activity of GILRP and GAAGGAF by 84.8% and 76.5%. This study revealed that module substitution is a feasible strategy to boost peptide activity, and provided information for the optimization of hydrolysate preparation conditions.

Parang Romang (Boehmeria virgata (Frost.) Guill.): Correlation of Phytochemistry with Antioxidant and Xanthine Oxidase Inhibitory Activities

Secondary metabolites such as phenolic and flavonoid from the plant are essential in their activity, especially activities related to the prevention of oxidation and the inhibition of xanthine oxidase. One plant that is believed to have prevention of oxidation and XOI and correlates with secondary metabolites is parang romang. The purpose of this study is to assess the antioxidant capacity and xanthine oxidase inhibitory activities of parang romang, and to examine their relationship with the TPC and TFC. Total phenolic and flavonoid were measured for all parts, and the DPPH, FRAP, and CUPRAC methods determined antioxidant capacity. The activity of xanthine oxidase inhibition was also assessed. Flavonoids, alkaloids, and coumarin were found in parang romang. The steroid/triterpenoid was found in the stem, leaves, and flower; saponin was in the roots and flower; quinone and tannin were only in the roots. The root gave the highest of TPC, while the flower had the highest TFC. The highest antioxidant capacity was found in roots, leaves, flowers, and stems. The highest xanthine oxidase inhibitory was given by leaves (9.74±0.14 µg/ml), followed by flower, steam, and rood. The correlation was shown between the phenolic and flavonoid quantities and the actions of antioxidants and xanthine oxidase inhibitors.

Debittering of Emblica (Phyllanthus emblica L.) fruit powder: Preparation and biological activity

Emblica, also known as Phyllanthus emblica L., is a drug homologous food that is rich in polyphenols with various biological activities. However, its bitterness and astringency pose a significant challenge to its utilization in food products. In this study, we aimed to identify the optimal conditions for debittering Emblica. Our findings revealed that the best debittering conditions were: temperature = 50 °C, pH = 4, α-l-rhamnosidase concentration 200 U/g, and time = 5 h. High-performance liquid chromatography (HPLC) and molecular docking analysis revealed that enzymatic hydrolysis partially removed bitterness compounds. The results of antioxidant activity, xanthine oxidase, and α-glucosidase inhibitory activity assays confirmed that the Emblica fruit powder still exhibited good biological activity after enzymatic debitterization. Moreover, gastric fluids treatment might contribute to the above enhancing effect of enzymatic hydrolysates of Emblica. This study provided a theoretical basis for promoting the processing and utilization of Emblica fruit powder, as well as understanding its biological activity.

Secondary metabolites from Scabiosa atropurpurea and their antioxidant and xanthine oxidase inhibitory activities

Secondary metabolites from Scabiosa atropurpurea and their antioxidant and xanthine oxidase inhibitory activities

The review on medicinal herbs in the treatment of gout through xanthine oxidase inhibitory activity: Call for more research strategy in the future

The review on medicinal herbs in the treatment of gout through xanthine oxidase inhibitory activity: Call for more research strategy in the future

In vitro assessment of probiotic potential and safety of two Lactobacillus gasseri strains isolated from mother's breast milk and infant's feces in Vietnam

Probiotics have multiple beneficial effects on human health, including modulation of the immune system, inhibition of enteric pathogens, and prevention of metabolic disorders. Lactic acid bacteria (LAB) are the most common bacterial strains used for probiotic production. Among those, species belonging to the Lactobacillus acidophilus complex, especially L. gasseri, were well characterized and reported for probiotics. This study evaluated the potential probiotic characteristics of two L. gasseri strains (designed as VTCC 12791 and VTCC 12792) isolated from a pair of mother's breast milk and infant's feces. Both strains completely survived in the simulated gastric juice, highly tolerated the simulated intestinal juice (81-84%), strongly adhered to the HT-29 cell (23.5% for VTCC 12791 strain and 5.5% for VTCC 12792 strain), and had antagonistic activity against food-borne pathogens of Aeromonas dhakensis, Vibrio vulnificus, and Listeria monocytogenes, which demonstrated better beneficial properties than those of the commercial reference Lacticaseibacillus casei Shirota (LcS) strain. Additionally, both strains exhibited xanthine oxidase inhibitory activity (approximately 24%), which can lead to reducing serum uric acid. Regarding the safety aspect, the strains were sensitive to several antibiotics of ampicillin, vancomycin, tetracycline, chloramphenicol, erythromycin, and possessed alpha-hemolytic activity, which were similar to those of LcS strain. Our results suggested that L. gasseri VTCC 12791 and VTCC 12792 are potential candidates for producing probiotics and functional foods. Further in vivo studies are needed to prove their potential health benefits, especially in the treatment of hyperuricemia.

Syntheses, Characterization, Crystal Structures and Xanthine Oxidase Inhibitory Activity of Hydrazones.

Four new fluoro-containing hydrazones were synthesized from 4-fluorobenzaldehyde with chloro- and nitro-substituted benzohydrazides. They are 3-chloro-N'-(4-fluorobenzylidene)benzohydrazide (1), 2-chloro-N'-(4-fluorobenzylidene)benzohydrazide (2), N'-(4-fluorobenzylidene)-4-nitrobenzohydrazide (3), and N'-(4-fluorobenzylidene)-3-nitrobenzohydrazide (4). The compounds have been characterized by IR and 1H NMR spectra, as well as X-ray single crystal determination. Xanthine oxidase (XO) inhibitory activity indicated that the nitro substituted compounds 3 and 4 have effective activity. Docking simulation was performed to insert the compounds into the crystal structure of xanthine oxidase at the active site to investigate the probable binding modes.

Data mining-guided alleviation of hyperuricemia by Paeonia veitchii Lynch through inhibition of xanthine oxidase and regulation of renal urate transporters

BackgroundHyperuricemia (HUA) is a metabolic disease characterized by a high level of uric acid (UA). The extensive historical application of traditional Chinese medicine (TCM) offers a range of herbs and prescriptions used for the treatment of HUA-related disorders. However, the core herbs in the prescriptions and their mechanisms have not been sufficiently explained. PurposeOur current investigation aimed to estimate the anti-HUA effect and mechanisms of Paeonia veitchii Lynch, an herb with high use frequency identified from data mining of TCM prescriptions. MethodsPrescriptions for HUA/gout treatment were statistically analyzed through a data mining approach to determine the common nature and use frequency of their composition herbs. The chemical constituents of Paeonia veitchii extract (PVE) were analyzed by UPLC-QTOF-MS/MS, while its UA-lowering effect was further evaluated in adenosine-induced liver cells and potassium oxonate (PO) and hypoxanthine (HX)-induced HUA mice. ResultsA total of 225 prescriptions involving 246 herbs were sorted out. The properties, flavors and meridians of the appearing herbs were mainly cold, bitter and liver, respectively, while their efficacy was primarily concentrated on clearing heat and dispelling wind. Further usage frequency analysis yielded the top 20 most commonly used herbs, in which PVE presented significant inhibitory activity (IC50 = 131.33 µg/ml) against xanthine oxidase (XOD), and its constituents showed strong binding with XOD in a molecular docking study and further were experimentally validated through XOD enzymatic inhibition and surface plasmon resonance (SPR). PVE (50 to 200 μg/ml) dose-dependently decreased UA levels by inhibiting XOD expression and activity in BRL 3A liver cells. In HUA mice, oral administration of PVE exhibited a significant UA-lowering effect, which was attributed to the reduction of UA production by inhibiting XOD activity and expression, as well as the enhancement of UA excretion by regulating renal urate transporters (URAT1, GLUT9, OAT1 and ABCG2). Noticeably, all doses of PVE treatment did not cause any liver injury, and displayed a renal protective effect. ConclusionsOur results first comprehensively clarified the therapeutic effect and mechanisms of PVE against HUA through suppressing UA production and promoting UA excretion with hepatic and renal protection, suggesting that PVE could be a promising UA-lowering candidate with a desirable safety profile for the treatment of HUA and prevention of gout.

SCREENING FOR ANTI-HYPERURICEMIA POTENTIAL OF SOME INDONESIAN MEDICINAL PLANTS THROUGH XANTHINE OXIDASE INHIBITION IN VITRO ASSAY

Objective: This study aimed to examine the in vitro xanthine oxidase inhibitory activity of 12 plants commonly used as gout medicines by the Indonesian people.
 Methods: The measurement of xanthine oxidase enzyme inhibitory activity was using UV spectrophotometry. The in vitro assessment of xanthine oxidase inhibition activity was tested on extracts from Eleutherine bulbosa (Mill.) Urb. Bulbs, Pandanus amaryllifolius Roxb. leaves, Alyxia reinwardtii Blume stem barks, Ruta angustifolia Pers aerial parts, Dioscorea hispida Dennst tubers, Plantago major L. leaves, Symphytum officinale L. roots, Euphorbia hirta L. aerial parts, Chromolaena odorata L. leaves, Solanum torvum Sw fruits, Peperomia pellucida L. Kunth. aerial parts and Strobilanthes crispa L. Blume leaves.
 Results: The results of this study showed that all tested plant extracts can inhibit xanthine oxidase activity with IC50 values varying from 27.80 µg/ml to 47.14 µg/ml. The IC50 value of allopurinol, used as positive control, was 1.24 µg/ml. Among all the tested plant extracts, Strobilanthes crispa L. Blume leaves extract has the best inhibitory activity against xanthine oxidase enzyme with IC50 value of 27.80 µg/ml.
 Conclusion: Strobilanthes crispa L. Blume leaves extract has the best inhibitory activity against xanthine oxidase, so It has the potential to be developed into herbal medicine to treat hyperuricemia. This study provides scientific support for the anti-hyperuricemia activity of these herbs, which are empirically used to treat gout.

Chemical Comparison and Identification of Xanthine Oxidase Inhibitors of Dioscoreae Hypoglaucae Rhizoma and Dioscoreae Spongiosae Rhizoma by Chemometric Analysis and Spectrum-Effect Relationship.

Dioscoreae hypoglaucae Rhizoma (DH) and Dioscoreae spongiosae Rhizoma (DS) are two similar Chinese herbal medicines derived from the Dioscorea family. DH and DS have been used as medicines in China and other Asian countries for a long time, but study on their phytochemicals and bioactive composition is limited. This present study aimed to compare the chemical compositions of DH and DS, and explore the anti-xanthine oxidase components based on chemometric analysis and spectrum-effect relationship. Firstly, an HPLC method was used to establish the chemical fingerprints of DH and DS samples, and nine common peaks were selected. Then, hierarchical clustering analysis, principal component analysis and orthogonal partial least squares discriminant analysis were employed to compare and discriminate DH and DS samples based on the fingerprints data, and four steroidal saponins compounds (protodioscin, protogracillin, dioscin, gracillin) could be chemical markers responsible for the differences between DH and DS. Meanwhile, the anti-xanthine oxidase activities of these two herbal medicines were evaluated by xanthine oxidase inhibitory assay in vitro. Pearson correlation analysis and partial least squares regression analysis were subsequently used to investigate the spectrum-effect relationship between chemical fingerprints and xanthine oxidase inhibitory activities. The results showed that four steroidal saponins, including protodioscin, protogracillin, methyl protodioscin and pseudoprogracillin could be potential anti-xanthine oxidase compounds in DH and DS. Furthermore, the xanthine oxidase inhibitory activities of the four selected inhibitors were validated by anti-xanthine oxidase inhibitory assessment and molecular docking experiments. The present work provided evidence for understanding of the chemical differences and the discovery of the anti-xanthine oxidase constituent of DH and DS, which could be useful for quality evaluation and bioactive components screening of these two herbal medicines.

Phytochemical screening and biological evaluation of Greek sage (Salvia fruticosa Mill.) extracts

This study explores the influence of extraction solvents on the composition and bioactivity of Salvia fruticosa extracts. Ultrasound-assisted extraction with water, ethanol and their mixtures in variable proportions was used to produce four different extracts. An untargeted UPLC/MS‑based metabolomics was performed to discover metabolites profile variation between the extracts. In the analyzed samples, 2704 features had been detected, of which 95 were tentatively identified. The concentrations of the important metabolites, namely, caffeic acid, carnosic acid, carnosol, rosmarinic acid, salvianolic acid B and scutellarin, were determined, using UPLC-PDA methods. Rosmarinic acid was the dominant metabolite and antioxidant in all tested extracts, except the aqueous extract, in which scutellarin was the most abundant compound. The extracts and standards were examined for antioxidant activity and xanthine oxidase (XO) inhibitory activity. The most diverse in terms of chemical composition and rich in antioxidant compounds was 70% ethanolic extract and the strongest antioxidant was caffeic acid. All analyzed extracts showed the ability to inhibit XO activity, but the highest value was recorded for 30% ethanolic extract. Among tested standards, the most potent XO inhibitor was caffeic acid. The results suggest that the leaves of Greek sage are a source of natural XO inhibitors and may be an alternative to drugs produced by chemical synthesis.

Understanding Hyperuricemia: Pathogenesis, Potential Therapeutic Role of Bioactive Peptides, and Assessing Bioactive Peptide Advantages and Challenges.

Hyperuricemia is a medical condition characterized by an elevated level of serum uric acid, closely associated with other metabolic disorders, and its global incidence rate is increasing. Increased synthesis or decreased excretion of uric acid can lead to hyperuricemia. Protein peptides from various food sources have demonstrated potential in treating hyperuricemia, including marine organisms, ovalbumin, milk, nuts, rice, legumes, mushrooms, and protein-rich processing by-products. Through in vitro experiments and the establishment of cell or animal models, it has been proven that these peptides exhibit anti-hyperuricemia biological activities by inhibiting xanthine oxidase activity, downregulating key enzymes in purine metabolism, regulating the expression level of uric acid transporters, and restoring the composition of the intestinal flora. Protein peptides derived from food offer advantages such as a wide range of sources, significant therapeutic benefits, and minimal adverse effects. However, they also face challenges in terms of commercialization. The findings of this review contribute to a better understanding of hyperuricemia and peptides with hyperuricemia-alleviating activity. Furthermore, they provide a theoretical reference for developing new functional foods suitable for individuals with hyperuricemia.

Four new constituents from the fruits of Cyclocodon lancifolius (Roxburgh) Kurz

Phytochemical analysis of the fruits of Cyclocodon lancifolius led to the isolation of two new phenylpropanoid-derived glycosides (1−2), two new geranyl glucosides (3−4), and nine known compounds (5–13). Their chemical structures were elucidated by extensive spectroscopic data. The absolute configuration of the sugar moiety was determined by hydrolysis and derivatization. All compounds were evaluated for their xanthine oxidase (XO) and α-glucosidase inhibitory activities, and four compounds showed weak inhibitory activity towards XO.

Polyphenol Composition, Antioxidant Capacity and Xanthine Oxidase Inhibition Mechanism of Furong Plum Fruits at Different Maturity Stages.

An experiment was conducted on the polyphenol content, flavonoid content, anthocyanin content, and antioxidant capacity of Furong plum (Prunus salicina Lindl. cv. "furong") at different maturity stages to determine the most suitable maturity stage. The inhibition of plum polyphenols on xanthine oxidase (XOD) was measured, and its kinetics were studied to reveal the inhibitory mechanism. The experimental results showed that the polyphenol, flavonoid and anthocyanin contents of plums at the ripe stage were the highest, reaching 320.46 mg GAE/100 g FW, 204.21 mg/100 g FW, and 66.24 mg/100 g FW, respectively, in comparison those of the plums at the immature and mid-ripe stages. The antioxidant capacity of the ripe plums was stronger than it was during the other stages of the plums growth. Among them, the total polyphenols of the ripe plums exhibited the strongest antioxidant capacity (IC50 values against DPPH and hydroxyl radicals were 28.19 ± 0.67 μg/mL and 198.16 ± 7.55 μg/mL, respectively), which was between the antioxidant capacity of the free polyphenols and bound polyphenols. The major phenolic monomer compounds of plum polyphenols were flavan-3-ols (epicatechin, catechin, proanthocyanidin, and procyanidin B2), flavonols (myricetin), and phenolic acids (chlorogenic acid, ferulic acid, and protocatechuic acid). Additionally, plum polyphenols exhibited a strong inhibitory effect on XOD, with an IC50 value of 77.64 μg/mL. The inhibition kinetics showed that plum polyphenols are mixed-type inhibitors that inhibit XOD activity and that the inhibition process is reversible. The calculated values of Ki and α were 16.53 mmol/L and 0.26, respectively.