Xanthine Oxidase Inhibitory Activity Research Articles

Identification of Hyperuricemia Alleviating Peptides from Yellow Tuna Thunnus albacares.

The development of food-derived antihyperuricemic substances is important for alleviating hyperuricemia (HUA) and associated inflammation. Here, novel peptides fromThunnus albacares (TAP) with strong antihyperuricemic activity were prepared. TAP was prepared by alkaline protease (molecular weight <1000 Da), with an IC50 value of xanthine oxidase inhibitory activity of 2.498 mg/mL, and 5 mg/mL TAP could reduce uric acid (UA) by 33.62% in human kidney-2 (HK-2) cells (P < 0.01). Mice were fed a high-purine diet and injected with potassium oxonate to induce HUA. Oral administration of TAP (600 mg/kg/d) reduced serum UA significantly by 42.22% and increased urine UA by 79.02% (P < 0.01) via regulating urate transporters GLUT9, organic anion transporter 1, and ATP-binding cassette subfamily G2. Meantime, TAP exhibited hepatoprotective and nephroprotective effects, according to histological analysis. Besides, HUA mice treated with TAP showed anti-inflammatory activity by decreasing the levels of toll-like receptor 4, nuclear factors-κB p65, NLRP3, ASC, and Caspase-1 in the kidneys (P < 0.01). According to serum non-targeted metabolomics, 91 differential metabolites between the MC and TAP groups were identified, and purine metabolism was considered to be the main pathway for TAP alleviating HUA. In a word, TAP exhibited strong antihyperuricemic activity both in vitro and in vivo.

Stilbene derivatives from Gnetum montanum Markgr. with their xanthine oxidase inhibition activity

AbstractPhytochemical study on the methanol extract of the trunks of Gnetum montanum Markgr. led to the isolation of one new stilbene derivative, (E)‐2′‐methoxy‐3,5,5′‐trihydroxystilbene (1) and six known compounds, lehmbachol (2), gnetulin (3), trans‐shegansu B (4), cis‐shegansu B (5), (+)‐hannokinol (6), and gnetol (7). Their chemical structures were determined by spectroscopic analyses including HR‐ESI‐MS, 1D and 2D NMR, and circular dichroism methods in comparison with the reported data. In addition, compounds 1–5 showed xanthine oxidase inhibitory activity with IC50 values of 13.6, 35.2, 38.7, 43.4, and 47.7 µm, respectively, compared to the positive control, allopurinol, which showed IC50 value of 2.9 µm.

Effect of Lacticaseibacillus rhamnosus L08 fermentation on xanthine oxidase inhibitory activity and flavour profile of honeysuckle (Lonicera japonica thunb.)

Xanthine oxidase (XOD) catalyses the oxidation of hypoxanthine and xanthine to uric acid, and inhibition of its activity has become the main strategy to reduce uric acid production. Honeysuckle (HON) which is rich in polyphenols potentially has the capacity to inhibit XOD activity. However, it carries the bitter and astringent flavor as well as many traditional Chinese medicines, along with that most of the polyphenols in HON exist in bound form, the exploitation and application of HON in food is limited. In this study, we investigated the effects of Lacticaseibacillus rhamnosus L08 fermentation on the bioactive components, XOD inhibitory activity and flavour characteristics of HON. The results showed that the XOD inhibitory activity was increased by 2.08 times after 96 h of fermentation. It was demonstrated that the increase in the total flavonoid content and total phenol content was the main reason for the enhancement of the fermentation solution's XOD inhibitory activity and antioxidant activity. Moreover, the fermentation also enriched the composition of volatile components of HON and reduced levels of undesirable flavour substances, which made the usage of fermented HON as functional food or in pharmaceutical use feasible and applicable.

Effects of Smilax China L. extracts on Hyperuricemia chicken Model via inhibiting xanthine oxidase activity

Effects of Smilax China L. extracts on Hyperuricemia chicken Model via inhibiting xanthine oxidase activity

A potential therapeutic agent for the treatment of hyperuricemia and gout: 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide

Uric acid, the metabolic product of purines, relies on xanthine oxidase (XOD) for production. XOD is a target for the development of drugs for hyperuricemia (HUA) and gout. Currently, treatment options remain limited for gout patients. 3, 4-Dihydroxy-5-nitrobenzaldehyde (DHNB) is a derivative of the natural product protocatechualdehyde with good biological activity. In this work, we identify a DHNB thiosemicarbazide class of compounds that targets XOD. 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazone can effectively inhibit XOD activity (IC50 value: 0.0437 μM) and exhibits a mixed inhibitory effect. In a mouse model of acute hyperuricemia, a moderate dose (10 mg/kg.w) of 3,4-dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide effectively controlled the serum uric acid content and significantly inhibited serum XOD activity. In addition, 3,4-Dihydroxy-5-nitrobenzaldehyde phenylthiosemicarbazide showed favorable safety profiles, and mice treated with the target compound did not show any symptoms of general toxicity following a single dose of 500 mg/kg. In the allopurinol group, 50 % of the mice died. These results provide a structural framework and mechanism of XOD inhibition that may facilitate the design of hyperuricemia and gout treatments.

Xanthine oxidase inhibitory constituents from the roots of Ampelopsis japonica

Bioassay-guided purification of the xanthine oxidase (XOD) inhibitory extract of the roots of Ampelopsis japonica resulted in the isolation of two new triterpenoids (1-2), designated Ampejaponoside A and B, along with sixteen known compounds (3-18). The structures of Ampejaposide A and B were elucidated by comprehensive analysis of spectroscopic data with the structures of the known compounds 3-18 confirmed by comparison the spectral data with corresponding values reported in literatures. All the isolates were evaluated for their XOD inhibitory activity in vitro. As a result, compounds 2, 8, and 14-16 displayed significant XOD inhibitory effect, particularly 16 being the most potent with an IC50 value of 0.21 μM, superior to positive substance allopurinol (IC50 1.95 μM). Molecular docking uncovered a unique interaction mode of 16 with the active site of XOD. The current study showed that the triterpenoids and polyphenols from A. japonica could serve as new lead compounds with the potential to speed up the development of novel XOD inhibitors with clinical potential to treat hyperuricaemia and gout.

Ellagitannins from pomegranate (Punica granatum L.) flower with xanthine oxidase and α-glucosidase inhibitory activities

In the course of our research on utilizing edible flower resources to promote health, five ellagitannins (1–5) were isolated from pomegranate (Punica granatum L.) flower by bioassay-guided fractionation. Among them, mallotusinin (1) and tercatain (2) were first isolated from pomegranate flower, and punicatannin D (4) was an unprecedented compound. Compounds 1–3 exhibited significant xanthine oxidase (XO) inhibitory activity compared with allopurinol, and a potent inhibition on α-glucosidase that was superior to acarbose was observed for compounds 1–4. The XO inhibitory activity is positively correlated with the amount of galloyl moiety (3 > 2 > 1). Presenting tetrahydroxydibenzofuranoyl substituent or increasing the number of galloyl group enhanced the inhibition capacity of α-glucosidase (1 > 3 > 2). The inhibitory mechanism was further clarified in terms of kinetic studies and molecular docking. This study revealed that the ellagitannins present in pomegranate flower might be promising functional food ingredients with anti-hyperuricemia and anti-hyperglycemia properties.

Xanthine oxidase and nitric oxide inhibitory activities of compounds isolated from Gomphrena celosioides

AbstractIn this study, the investigation of xanthine oxidase and nitric oxide formation inhibitory activities of three compounds isolated from aerial part of Gomphrena celosioides, a folk medicinal plant for treatment of gout disease, is reported. The isolated compounds were determined based on NMR and ESI‐MS spectra, they are umbellatosides B, 20‐hydroxyecdysone, and 20‐hydroxyecdysone‐20,22‐monoacetonide. Biological activity results indicated that three compounds showed great activities, in which, umbellatosides B has good activity with IC50 value of 33.78 ± 0.49 and 19.55 ± 0.61 µm for xanthine oxidase and nitric oxide inhibitory activities, respectively. This is the report on the xanthine oxidase and nitric oxide inhibitory activities of three compounds that were first time isolated from the G. celosioides.

Enzymatic Hydrolysis Optimization of Yak Whey Protein Concentrates and Bioactivity Evaluation of the Ultrafiltered Peptide Fractions.

Yak whey protein concentrates (YWPCs) have good functional properties, but there is still a gap in the study of their peptides. In this study, peptides were obtained by enzymatic hydrolysis, and the bioactivity of each ultrafiltration fraction was evaluated using an optimal process. YWPCs were isolated and purified from yak milk as the raw material. Alkaline protease, trypsin, and papain were used to hydrolyze YWPCs. The protease with the highest degree of hydrolysis (DH) and peptide concentration was selected as the most suitable enzyme. The effects of pH, temperature, time, and the enzyme-to-substrate ratio (E/S) on the DH and peptide concentration were investigated, and response surface methodology was utilized to optimize the hydrolysis process. The hydrolysate was separated using ultrafiltration membranes with molecular weight cut-offs of 10 kDa, 5 kDa, 3 kDa, and 1 kDa. The bioactivity of each ultrafiltration component was analyzed, including the inhibition rates of α-amylase and xanthine oxidase (XOD) activities and the scavenging rates of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radicals. The results indicated that alkaline protease was the best enzyme for hydrolyzing YWPCs. The peptide concentration in the YWPC hydrolysate was the highest (17.21 mg/mL) at a pH of 8 and a concentration of 7500 U/g, after 2.5 h at 62 °C. The enzymatic hydrolysate was ultrafiltered to yield four peptide fractions, of which the <1 kDa peptides exhibited the highest α-amylase inhibitory activity (22.06%), XOD inhibitory activity (17.15%), and ABTS cationic free radical scavenging rate (69.55%). This demonstrates the potential of YWPC hydrolyzed peptides for hypoglycemic, uric acid-lowering, and antioxidant applications, providing a theoretical basis for the high-value utilization of YWPCs.

In vivo and in vitro insights into the anti-hyperuricemic effects of sacha inchi (plukenetia volubilis l.) leaves extract rich in polyphenols

Sacha inchi (SI, Plukenetia volubilis L.) is a South American oleaginous crop with multiple health benefits and has been traditionally used to treat various ailments due to its bioactive ingredients such as polyphenols and flavonoids. In this study, a variety of compounds including three flavonoids (epigallocatechin, luteolin-3′,7-di-O-glucoside and cosmosiin), two polyphenols (gallic acid and 4-hydroxycoumarin) and three organic acids (malic acid, citric acid and 2-isopropylmalic acid) were firstly identified by UHPLC-QQQ-MS. Subsequently, in vitro results show that SI leaf aqueous extract (SILE) exhibit potential to lower uric acid (UA) by affecting mRNA levels of UA synthases (XO and HGPRT) with neglectable impacts on cell viability of liver cells (L02). In vivo experiments further suggest that SILE can effectively reduce the levels of serum UA and renal inflammatory cytokines (Il-1β, Il-6 and Tnf-α), and improve renal function indicators (serum Cr and BUN), thereby repairing kidney injury in both acute and chronic hyperuricemic (HUA) animal models. In addition, SILE also improve UA metabolism by inhibiting UA biosynthesis and reabsorption and promoting UA excretion. 1H NMR-based metabolomics reveals that SILE effectively regulate the levels of glucose, amino acid, purine and pyrimidine that are involved in UA metabolic pathway in kidney of HUA mice. These findings demonstrate that SILE rich in polyphenols and flavonoids has a great potential for HUA treatment by inhibiting xanthine oxidase activity and improving UA metabolism.

Screening and characterization of potential anti-gout components from Polygonum cuspidatum by integration off-line two-dimensional liquid chromatography-mass spectrometry with affinity ultrafiltration and on-line HPLC-ABTS

Polygonum cuspidatum (P. cuspidatum) is a traditional herbal medicine with a long history and proven efficacy in treating gout. However, due to the complexity of composition and extensive content distribution, the substance basis of its anti-gout effectiveness is still unclear. A strategy was proposed via integrating off-line two-dimensional liquid chromatography (2D-LC) and targeted rapid screening technology based on ultrafiltration-liquid chromatography-mass spectrometry (UF-LC/MS) and on-line high-performance liquid chromatography-2, 2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (HPLC-ABTS) to accomplish high coverage and high throughput screening of anti-gout components from P. cuspidatum. As a result, twenty components were screened from P. cuspidatum extract with both xanthine oxidase (XOD) inhibitory activity and free radical scavenging activity, then were preliminarily identified by high-resolution electrospray ionization-quadrupole-time-of-flight mass spectrometer (ESI-Q-TOF/MS). The screened results were verified by the in vitro assays. Meanwhile, molecular docking further elucidated that the screened bioactive ingredients had favourable binding capabilities with XOD. The performance of this study can achieve high efficiency and high coverage screening of the anti-gout components from P. cuspidatum, which provides methodology and strategy support for the rapid screening of bioactive ingredients from complex medicinal plants.

Study on the chemical composition and in vitro enzyme inhibition of different processed products of Gastrodia elata

Gastrodia elata (GE) has a variety of processed products. However, there are few studies on the comparison of the chemical composition and activity differences of various processed products. In order to further study, the raw materials and different processed products of GE were chemically characterized in detail by UPLC-ESI-Q-TOF-MS/MS, and the content of 7 constituents were determined by HPLC-UV. The activities of different products against α-glucosidase, xanthine oxidase (XO) and acetylcholinesterase (AchE) were evaluated. In total, 170 compounds were identified, primarily including 31 phenolics, 109 parishins, 20 amino acids, 5 nucleotides, and 5 organic acids, and first discovery of 4 potential new compounds. The differences in the chemical composition of GE and its products are mainly in phenolics and parishins. Fresh GE (FGE) extract has the highest content of p-hydroxybenzyl alcohol and p-hydroxybenzaldehyde. The parishins content of dried GE processed products were higher than FGE. And, FGE extract showed the strongest inhibitory activity of α-glucosidase (IC50 was 0.47 mg/mL) and AchE (IC50 was 0.56 mg/mL), and ginger GE extract showed the strongest XO inhibitory activity (IC50 was2.59 mg/mL ), all below corresponding standard inhibitors. And this is the first time that the inhibitory activity of GE against XO has been evaluated.

A Candidate for Health Promotion, Disease Prevention and Treatment, Common Rue (Ruta graveolens L.), an Important Medicinal plant in Traditional Medicine.

Ruta graveolens L. belongs to Rutaceae; it is a semi-wood perennial or a small evergreen sub-shrub, which is native to Southern Europe, West of Asia and Northern Africa. The goal of this manuscript was to outline the most notable traditional and modern advantages and pharmaceutical benefits of common rue. The manuscript covers review articles, randomized control experiments, analytical studies and observations, which have been gathered from different sources such as Google Scholar, Scopus, Science Direct and PubMed. A review of the literature was carried out using the keywords rutin, Ruta graveolens L., rue, common rune, coumarin, natural products and pharmaceutical benefits. Rue contains quinoline alkaloids, such as graveoline and graveolinine, acridone alkaloids, such as furacridone and gravacridone, the furanoquinoline dictamnine, coumaris, such as gravelliferone, isorutarin, rutacultin, rutaretin, and suberenone, and the furanocoumarins 5-methoxypsoralen (bergapten) and 8-methoxypsoralen (xanthotoxine). Most of its aromatic and medicinal properties are from its rutin, and essential oil. It has been used in folk medicines as a stimulant, anti-inflammatory and analgesic properties, anti-androgenic activity, anti-hyperglycemic effects, anti-hyperlipidemic effects, xanthine oxidase inhibition activity, anticancer properties. According to pharmacological and phytochemical advantages, pennyroyal shows its importance as a medicinal plant in both modern medicinal science and traditional medicine.

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.