Marine Fish Protein Peptide Regulating Potassium Oxonate-Induced Intestinal Dysfunction in Hyperuricemia Rats Helps Alleviate Kidney Inflammation

Antihyperuricemia Bioactive Substances Derived from Marine Organisms

Hyperuricemia is a metabolic disorder attributed to dysregulated purine metabolism or insufficient uric acid excretion. With a high incidence rate and comorbidities burden, hyperuricemia brings enormous pressure to society and attracts much attention nowadays. Though several urate-lowering drugs (including xanthine oxidase inhibitors, uricosuric drugs, and recombinant uricase) are available in clinical practice, their use is often limited due to serious side effects or contraindications. The development of novel urate-lowering drugs and functional foods is in the spotlight. Regarded as an important source of bioactive substances, marine organisms, including seaweeds, animals, and microorganisms, have yielded a large number of bioactive substances with novel structures and unique pharmacological activities. Up to the present, numerous marine organisms-derived bioactive substances have shown potential in combating hyperuricemia. Thus, this review discusses the antihyperuricemia substances derived from marine organisms and summarizes their antihyperuricemia pharmacological properties, with the aim of providing new insights for the development of antihyperuricemia drugs or functional foods from marine organism resources.

Galangin Protects against Hyperuricemia via Ameliorating Gut-Kidney Axis Dysfunction in Mice

Hyperuricemia (HUA) is often associated with renal injury and intestinal flora disturbance. Galangin, a polyphenolic compound found in Alpinia officinarum and propolis, has demonstrated the capacity to inhibit xanthine oxidase (XO) activity both in vitro and in silico; however, the precise mechanisms underlying its effects in vivo remain unclear. This study aims to investigate the effect of galangin on uric acid (UA) metabolism as a prospective strategy for lowering UA and further explore the underlying mechanisms. Galangin mitigates kidney tissue injury and fibrosis, reduces the serum UA level via inhibiting UA synthesis in the liver, and promotes UA excretion in the kidney. Molecular docking results also uncovered the structure-activity relationship of galangin and the UA transporters GLUT9, URAT1, ABCG2, and OAT1, implying a potential interaction. Also, galangin mitigated the HUA-activated NF-κB/MAPK signaling pathway in the kidney, as well as colon tissue damage and barrier dysfunction, which are closely linked to deteriorated intestinal permeability. Moreover, galangin remedied the alterations in intestinal microecology caused by HUA, encompassing changes in the structure and composition of gut microbial species as well as the metabolism of SCFAs. Collectively, this study demonstrates that galangin exerted an improvement on HUA by ameliorating gut-kidney axis dysfunction.

Gut microbiota and NLRP3 inflammasome activation in hemodialysis patients: exploring the link with systemic inflammation

BACKGROUND

The Nod-Like Receptor Pyrin domain-containing 3 (NLRP3) inflammasome is a critical sensor of bacterial signals and metabolites, initiating an inflammatory response. Chronic kidney disease (CKD) is often accompanied by systemic inflammation, which can be involved with gut dysbiosis. Considering this interplay, we aimed to explore the potential association between NLRP3 inflammasome expression and gut microbiota in CKD patients undergoing hemodialysis (HD).

METHODS AND RESULTS

This research comprises a cross-sectional pilot study involving twelve HD patients [59.2 ± 13.4 years, six women, BMI 26.6 ± 3.5 kg/m2, 48.6 (20.1-77.2) months] on dialysis. The gut microbiota was evaluated by the 16 S ribosomal RNA gene. The mRNA expression of NLRP3 was assessed using real-time quantitative polymerase chain reaction (qPCR). Plasma levels of IL-1β were measured by ELISA. Fusobacteria and Fusobacterium negatively correlated with the mRNA expression levels of NLRP3 and IL-1β (p < 0.05). A positive correlation was observed between mRNA expression of NLRP3 and Lentisphaerae, Erysipelaloclostrium and Victivallis (p < 0.05). The relative abundances of Lentisphaerae, Spirochaetes, Abscicoccus, Colidextribacter, Desulfovibrio, Fournierella, Lawsonibacter, Ruminococcus, and Victivallis were positively correlated with IL-1β mRNA expression (p < 0.05). Regarding Archaea, IL-1β mRNA expression was positively correlated with Methanobrevibacter (p < 0.05).

CONCLUSION

In CKD patients undergoing hemodialysis, gut microbiota may be involved in NLRP3 activation and IL-1β expression, contributing to inflammation.

Evaluation of anti-hyperuricemic and nephroprotective activities and discovery of new XOD inhibitors of Morus alba L. root bark

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, Morus alba L. root bark (MAR) has diuretic and detumescent effects, which is used in prescriptions like Niaoduqing granules for hyperuricemia treatment. However, the anti-hyperuricemic and nephroprotective activities, underlying mechanism and material basis of MAR have not been reported.

AIM OF THE STUDY

This research aimed to explore the anti-hyperuricemic and nephroprotective activity and mechanism of MAR, along with the pursuit of potential xanthine oxidase (XOD) inhibitors within MAR.

MATERIALS AND METHODS

XOD inhibitory assay and hyperuricemic mice model were employed to screen and estimate the active fraction of MAR. Then, active compositions were isolated and elucidated by diverse separation and spectroscopic techniques. The enzyme inhibition mechanism of the active compositions was investigated by enzyme kinetic and molecular docking.

RESULTS

The ethyl acetate fraction (MAR-EA) showed the strongest inhibitory activity against XOD. In hyperuricemic mice, MAR-EA decreased serum uric acid levels by suppressing XOD activity and modulating renal uric acid transporters (URAT1, GLUT9, ABCG2). Moreover, it alleviated hyperuricemia-induced kidney damage, which may be related to inhibiting the production of inflammatory factors. Noticeably, the combination of MAR-EA with allopurinol showed a synergistic effect. Meanwhile, a Diels-Alder adduct, albanol A (1) was isolated from MAR-EA with excellent XOD inhibition activity (IC50 = 0.116 mg/mL), which was categorized as a mixed-type XOD inhibitor. The molecular docking outcomes demonstrated that albanol A (1) exhibited a desirable interaction with XOD.

CONCLUSION

This research supports MAR and albanol A as anti-hyperuricemic drug candidates, laying a foundation for further exploration.

Oleanolic Acid Alleviates Hyperuricemia via Gut Microbiota Control the Integrity of Gut Barrier and the Expressions of Urate Transporter in Mice

Hyperuricemia (HUA) is a globally prevalent metabolic disorder characterized by an imbalance in uric acid (UA) production and excretion. In this study, we found that oleanolic acid (OA), a natural pentacyclic triterpene, effectively reduced HUA and associated kidney injury in C57BL/6J mice. A 12-week OA treatment significantly and dose-dependently reduced UA and creatinine levels in serum and urine while suppressing hepatic xanthine oxidase activity in HUA mice. Mechanistic analysis revealed that OA modulates the expression of urate transporters including ABCG2, GLUT9, and URAT1 in the kidney and small intestine. Furthermore, OA restored gut microbiota imbalances, increased short-chain fatty acid production, and enhanced the expressions of intestinal tight junction proteins in HUA mice, thereby improving gut barrier integrity in HUA mice. Consequently, fecal microbiota transplantation (FMT) was employed to illustrate the major mediating role of gut microbiota in OA's alleviation of HUA in mice. Recipient HUA mice transplanted with feces from OA-treated HUA mice exhibited significantly lower blood and urinary UA levels, reduced kidney inflammation, and improved gut microbiota balance compared to those receiving feces from untreated HUA mice (p < 0.05). Additionally, FMT normalized urate transporter expression and reinforced intestinal tight junctions in recipient mice. These findings underscore that OA mitigates HUA primarily by modulating gut microbiota, regulating urate transporter expression, and reinforcing gut barrier integrity, offering novel insights into its preventive potential for managing HUA and related complications.

Exploring the structures and molecular mechanisms of bioactive compounds from marine foods for hyperuricemia prevention: a systematic review

Hyperuricemia, characterized by an elevation in serum uric acid (UA) levels, stands as a significant metabolic ailment threatening human well-being. Presently, dietary adjustments have become a crucial strategy in managing serum UA levels among individuals grappling with hyperuricemia and gout. Given its unique ecosystem, the ocean hosts a plethora of organisms boasting distinct structures and active components. The marine bioactive substances, such as bioactive peptides, polysaccharides, lipids, and small molecules, have garnered attention in the research and development of modern functional foods and biomedicine due to their profound efficacy and distinctive compositions. Notably, the functional components of marine foods have been studied for their potential in preventing hyperuricemia. However, the precise molecular mechanism underlying their actions remain incompletely elucidated. This review article highlights the diversity of marine active compounds and the latest progress in understanding urate-lowering mechanism. Principal mechanisms primarily encompass the regulation of UA metabolism, maintenance of intestinal homeostasis, mitigation of inflammatory responses, and alleviation of oxidative stress. Furthermore, we scrutinized the constraints of prior studies and provided recommendations. In sum, this article furnished a valuable resource concerning the intervention of bioactive compounds sourced from marine foods in the context of hyperuricemia.

ENTPD8 overexpression enhances anti-PD-L1 therapy in hepatocellular carcinoma via miR-214-5p inhibition

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths globally, with poor prognosis due to late diagnosis and limited treatment options. In this study, we evaluated the expression of ectonucleoside triphosphate diphosphohydrolase 8 (ENTPD8) in HCC tissues and its clinical significance. Immunohistochemistry, The Cancer Genome Atlas (TCGA) data, and single-cell expression analysis revealed reduced ENTPD8 levels in liver cancer compared to adjacent tissues, with ENTPD8 primarily expressed in tumor cells within the tumor tissue. In vitro assays demonstrated that ENTPD8 inhibits HCC cell proliferation, invasion, and migration. Mechanistically, ENTPD8 regulates programmed death-ligand 1 (PD-L1) expression through miR-214-5p modulation. In vivo, ENTPD8 overexpression combined with anti-PD-L1 treatment enhanced therapeutic efficacy in HCC mouse models. These findings suggest that ENTPD8 may serve as a prognostic marker and therapeutic target for HCC, offering potential strategies for improving treatment outcomes.

Mechanisms Associated With Renal Injury in Hyperuricemia and Strategies for the Development of Natural Active Substances

Hyperuricemia (HUA) is a metabolic condition resulting from an abnormality in the process of purine metabolism. Its occurrence has been on the rise globally. The results of relevant studies show that 5% to 12% of HUA patients will eventually develop gout, and one-third of these patients may involve the kidneys and develop kidney disease. Although the severe renal health hazards associated with excessive uric acid levels are well known, the specific molecular mechanisms remain unknown. Therefore, this paper provides insights into the mechanisms and related chain reactions of HUA leading to renal injury from three perspectives: imbalance of intestinal homeostasis, oxidative stress response, and NLRP3 inflammasome. In addition, standing against the background of the strong side effects and high tolerability disadvantages of commercially available uric acid-lowering drugs such as allopurinol, benzbromarone, and febuxostat, the development of a new active anti-hyperuricemic drug with fewer side effects is justified. This article reviews the progress of research on natural actives (probiotics, dietary polyphenols, peptides) with a high safety profile, multi-targeting, and integrative modulatory effects, in an attempt to provide some ideas for drug developers.

Uricase from Alkalihalobacillus clausii, a Candidate for Industrial Application of Reducing Uric Acid Content of Bean Products

Microbial uricase is an essential enzyme in purine degradation and the development of low-purine food. High enzyme activity and an appropriate optimum pH must be established for low-purine food. Uricases from Neurospora crassa, Streptomyces coelicolor, Alkalihalobacillus clausii, Bacillus subtilis, and Brevibacterium casei were heterologously expressed in Escherichia coli. Uricase from Alkalihalobacillus clausii (AC-PUCL) showed the most potent enzyme activity (249.19 IU/mL) at 37 °C and pH 7.0. This is close to the pH of plant-based food. The Km and Km/Kcat values of AC-PUCL were 30.12 μM and 1.46 s-1 μM-1, respectively. Furthermore, the crystal structures of uricases from different sources revealed that hydrogen bonds could enhance substrate affinity and strong enzyme activity. In addition, the high enzyme activity may be contributed by the active pockets with an appropriate size. Finally, AC-PUCL helped reduce the purine substances in soybean, pea, and kidney bean, with residual uric acid can not be detected at pH 8.6, suggesting a promising industrial application.

Transcriptomic Analysis Reveals the Potential Mechanism of Cardamine circaeoides Hook.f. & Thomson in Lowering Serum Uric Acid by Reducing Inflammatory State Through CCR7 Target

Cardamine circaeoides Hook.f. & Thomson (CC) is a traditional medicinal herb with multiple biological activities. In previous studies, we have identified its serum uric acid (SUA) lowering effects and speculated that Cardamine circaeoides water extract (CCE) may exert anti-hyperuricemia effects related to its anti-inflammatory activity. This study aims to further investigate the molecular mechanism underlying these effects at the mRNA level through transcriptomic analysis, quantitative reverse transcription polymerase chain reaction (RT-qPCR), molecular docking, and Western blotting. CCE effectively reduced SUA and improved renal function in a dose-dependent manner in hyperuricemia rats. Cytokine-cytokine receptor interaction pathway was significantly altered by CCE. An additional study identified a number of genes (IL27, Inhbe, CCR7, CXCR3, IL12RB1, CXCR5, Mstn, and GDF5) as regulators of the inflammatory response. Meanwhile, three key targets (IL27, Inhbe, and CCR7) were found to be significantly expressed at the mRNA level and have strong binding affinity with 22 components, among which Kaempferol 3-sophoroside 7-glucoside, Kaempferol-3-O-sophoroside, and Quercetin 3-sophoroside 7-glucoside have strong binding activities. Following this, Western blotting showed a significant increase in CCR7 expression. Our findings indicated that CCE regulated the cytokine-cytokine receptor interaction pathway through CCR7 to reduce the inflammatory state and exert an SUA-lowering effect.

Food-derived bioactive peptides with anti-hyperuricemic activity: A comprehensive review

Hyperuricemia (HU) is a metabolic disorder caused by the overproduction or underexcretion of uric acid (UA) in the human body. Several approved drugs for the treatment of HU are available in the market; however, all these allopathic drugs exhibit multiple side effects. Therefore, the development of safe and effective anti-HU drugs is an urgent need. Natural compounds derived from foods and plants have the potential to decrease UA levels. Recently, food-derived bioactive peptides (FBPs) have gained attention as a functional ingredient owing to their biological activities. In the current review, we aim to explore the urate-lowering potential and the underlying mechanisms of FBPs. We found that FBPs mitigate HU by reducing blood UA levels through inhibiting key enzymes such as xanthine oxidase, increasing renal UA excretion, inhibiting renal UA reabsorption, increasing anti-oxidant activities, regulating inflammatory mediators, and addressing gut microbiota dysbiosis. In conclusion, FBPs exhibit strong potential to ameliorate HU.

Harnessing Protein Hydrolysates and Peptides for Hyperuricemia Management: Insights into Sources, Mechanisms, Techniques, and Future Directions

Hyperuricemia (HUA) is a metabolic disorder characterized by an imbalance in uric acid production and excretion, frequently leading to gout and various chronic conditions. Novel bioactive compounds offer effective alternatives for managing HUA, reducing side effects of traditional medications. Recent studies have highlighted the therapeutic potential of protein hydrolysates and peptides in managing HUA. This review focuses on preparing and applying protein hydrolysates to treat HUA and explores peptides for xanthine oxidase inhibition. Particularly, we discuss their origins, enzymatic approaches, and mechanisms of action in detail. The review provides an updated understanding of HUA pathogenesis, current pharmacological interventions, and methodologies for the preparation, purification, identification, and assessment of these compounds. Furthermore, to explore the application of protein hydrolysates and peptides in the food industry, we also address challenges and propose solutions related to the safety, bitterness, oral delivery, and the integration of artificial intelligence in peptide discovery. Bridging traditional pharmacological approaches and innovative dietary interventions, this study paves the way for future research and development in HUA management, contributing to the utilization of proteins from different food sources. In conclusion, protein hydrolysates and peptides show significant promise as safe agents and dietary interventions for preventing and treating HUA.

Gut microecology: effective targets for natural products to modulate uric acid metabolism

Gut microecology,the complex community consisting of microorganisms and their microenvironments in the gastrointestinal tract, plays a vital role in maintaining overall health and regulating various physiological and pathological processes. Recent studies have highlighted the significant impact of gut microecology on the regulation of uric acid metabolism. Natural products, including monomers, extracts, and traditional Chinese medicine formulations derived from natural sources such as plants, animals, and microorganisms, have also been investigated for their potential role in modulating uric acid metabolism. According to research, The stability of gut microecology is a crucial link for natural products to maintain healthy uric acid metabolism and reduce hyperuricemia-related diseases. Herein, we review the recent advanced evidence revealing the bidirectional regulation between gut microecology and uric acid metabolism. And separately summarize the key evidence of natural extracts and herbal formulations in regulating both aspects. In addition,we elucidated the important mechanisms of natural products in regulating uric acid metabolism and secondary diseases through gut microecology, especially by modulating the composition of gut microbiota, gut mucosal barrier, inflammatory response, purine catalyzation, and associated transporters. This review may offer a novel insight into uric acid and its associated disorders management and highlight a perspective for exploring its potential therapeutic drugs from natural products.

Capsaicin Modulates Hepatic and Intestinal Inflammation and Oxidative Stress by Regulating the Colon Microbiota

We aimed to investigate the role of capsaicin (CAP) in modulating lipopolysaccharide (LPS)-induced hepatic and intestinal inflammation, oxidative stress, and its colonic microflora in mice. Thirty healthy male Kunming mice with similar body weights were randomly assigned to three groups: the control group (CON), the LPS group, and the CAP group, with ten mice in each group. The CON and the LPS groups received a daily dose of normal saline, respectively, while the CAP group received an equivalent dose of CAP. On the 28th day of the experiment, the LPS and the CAP groups were intraperitoneally injected with LPS, while the CON group was injected with an equal volume of normal saline. The results lead to the following conclusions. Compared to the LPS group, CAP improved the loss of hepatic lobular structure and significantly increased the duodenal villus length and ratio of villus length to crypt depth. CAP increased hepatic and colon interleukin-10 (IL-10) and decreased IL-6, IL-1β, and tumor necrosis factor (TNF-α) levels. CAP also increased hepatic catalase (CAT), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) expression, and decreased malondialdehyde (MDA) levels. CAP significantly increased the relative abundances of Mucispirillum, Helicobacter, Prevotellaceae-UCG-001, Colidextribacter, unclassified-f-Oscillospiraceae, and Odoribacter, some of which were closely related to hepatic and colonic immune and oxidative markers. CAP also decreased the overall content of short-chain fatty acids, except for propionic acid. Overall, CAP can regulate the colon microbiota and exert anti-inflammatory and antioxidant effects. Whether CAP exerts its anti-inflammatory and antioxidant effects by modulating the colonic microflora, mainly Mucispirillum spp. and Helicobacter spp., requires further investigation.

Anti-hyperuricemia bioactive peptides: a review on obtaining, activity, and mechanism of action

Hyperuricemia, a disorder of uric acid metabolism, serves as a significant risk factor for conditions such as hypertension, diabetes mellitus, renal failure, and various metabolic syndromes. The main contributors to hyperuricemia include overproduction of uric acid in the liver or impaired excretion in the kidneys. Despite traditional clinical drugs being employed for its treatment, significant health concerns persist. Recently, there has been growing interest in utilizing protein peptides sourced from diverse food origins to mitigate hyperuricemia. This article provides a comprehensive review of bioactive peptides with anti-hyperuricemia properties derived from animals, plants, and their products. We specifically outline the methods for preparing these peptides from food proteins and elucidate their efficacy and mechanisms in combating hyperuricemia, supported by in vitro and in vivo evidence. Uric acid-lowering peptides offer promising prospects due to their safer profile, enhanced efficacy, and improved bioavailability. Therefore, this review underscores significant advancements and contributions in identifying peptides capable of metabolizing purine and/or uric acid, thereby alleviating hyperuricemia. Moreover, it offers a theoretical foundation for the development of functional foods incorporating uric acid-lowering peptides.

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.

The synergism of Lactobacillaceae, inulin, polyglucose, and aerobic exercise ameliorates hyperglycemia by modulating the gut microbiota community and the metabolic profiles in db/db mice

This study aimed to assess the impact of Lactobacillaceae (L or H represents a low or high dose), inulin (I), and polydextrose (P) combined with aerobic exercise (A) on the composition of the gut microbiota and metabolic profiles in db/db mice. After a 12-week intervention, LIP, LIPA, and HIPA groups exhibited significant improvements in hyperglycemia, glucose tolerance, insulin resistance, inflammatory response, and short-chain fatty acid (SCFA) and blood lipid levels compared to type 2 diabetes mice (MC). After treatment, the gut microbiota composition shifted favorably in the treatment groups which significantly increased the abundance of beneficial bacteria, such as Bacteroides, Blautia, Akkermansia, and Faecalibaculum, and significantly decreased the abundance of Proteus. Metabolomics analysis showed that compared to the MC group, the contents of 5-hydroxyindoleacetic acid, 3-hydroxysebacic acid, adenosine monophosphate (AMP), xanthine and hypoxanthine were significantly decreased, while 3-ketosphinganine, sphinganine, and sphingosine were significantly increased in the LIP and LIPA groups, respectively. Additionally, LIP and LIPA not only improved sphingolipid metabolism and purine metabolism pathways but also activated AMP-activated protein kinase to promote β-oxidation by increasing the levels of SCFAs. Faecalibaculum, Blautia, Bacteroides, and Akkermansia exhibited positive correlations with sphingosine, 3-ketosphinganine, and sphinganine, and exhibited negative correlations with hypoxanthine, xanthine and AMP. Faecalibaculum, Blautia, Bacteroides, and Akkermansia may have the potential to improve sphingolipid metabolism and purine metabolism pathways. These findings suggest that the synergism of Lactobacillaceae, inulin, polydextrose, and aerobic exercise provides a promising strategy for the prevention and management of type 2 diabetes.

Soybean-derived antihypertensive hydrolysates attenuate Ang II-induced renal damage by modulating MAPK and NF-κB signaling pathways

Hypertension-induced kidney injury is considered a vital consequence of long-term and uncontrolled hypertension, which is commonly associated with an excessive accumulation of angiotensin II (Ang II) from hyperactivated RAS. Antihypertensive peptides have a significant effect on blood pressure regulation, but few studies have focused on the ameliorative function of antihypertensive peptides on renal injury. This study explored the effects of soybean protein-derived hydrolysate (SPH) on SHR and Ang II-induced HK-2 cells. SPH significantly attenuated blood pressure and alleviated renal pathological injury in SHRs after oral gavage administration. According to the pathological results, the kidneys of SHRs showed inflammation and SPH attenuated inflammatory cell infiltration in the kidneys of SHRs. Immunohistochemical analysis further revealed that SPH inhibited MCP-1 expression and increased Nrf2 expression in the kidneys. An in vitro HK-2 cell model demonstrated that SPH exhibited optimal activity for reducing Ang II-induced inflammatory cytokines and ROS overproduction. Mechanistically, SPH was observed to regulate MAPK/JNK and NF-κB signaling pathways. These findings indicate that potent antihypertensive SPH significantly ameliorates hypertension-induced kidney damage.

The alleviative effect of C-phycocyanin peptides against TNBS-induced inflammatory bowel disease in zebrafish via the MAPK/Nrf2 signaling pathways

INTRODUCTION

Ulcerative colitis (UC) is an incurable and highly complex chronic inflammatory bowel disease (IBD) affecting millions of people worldwide. C-phycocyanin (C-PC) has been reported to possess outstanding anti-inflammatory activities and can effectively inhibit various inflammation-related diseases. Whether C-PC-derived bioactive peptides can inhibit intestinal inflammation is worth research and consideration.

METHODS

The inhibition activities of three anti-neuroinflammatory peptides were evaluated using 2-4-6-trinitrobenzen sulfonic acid (TNBS)-induced zebrafish colitis model. Subsequently, the abilities of peptides to promote gastrointestinal motility were also examined. The changes in the intestinal pathological symptoms and ultrastructure of intestinal, reactive oxygen species (ROS) levels, and antioxidant enzymes were then determined after co-treatment with peptides and TNBS. Transcriptome analysis was used to investigate the underlying ameliorating TNBS-induced colitis effects molecular mechanisms of better activity peptide. Furthermore, quantitative reverse-transcription polymerase chain reaction and molecular docking techniques verified the mRNA sequencing results.

RESULTS

Three peptides, MHLWAAK, MAQAAEYYR and MDYYFEER, which significantly inhibit macrophage migration, were synthesized. The results showed that these peptides could effectively alleviate the inflammatory responses in the TNBS-induced zebrafish model of colitis. In addition, co-treatment with TNBS and C-PC peptides could decrease ROS production and increase antioxidant enzyme activities in zebrafish larvae. Moreover, MHLWAAK had the most significantly therapeutic effects on colitis in zebrafish. The transcriptome analysis suggests that the effect of MHLWAAK on TNBS-induced colitis may be associated with the modulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinase (MAPK) signaling pathway associated genes. In addition, molecular docking was conducted to study the prospective interaction between peptides and the key proteins that streamline the Nrf2 and MAPK signaling pathways. IL-6, JNK3, TNF-α, KEAP1-NRF2 complex and MAPK may be the core targets of MHLWAAK in treating colitis.

CONCLUSION

The results suggested that the three C-PC-derived peptides could ameliorate TNBS-induced colitis in zebrafish, and these peptides might be a promising therapeutic candidate for UC treatment.

Causal relationship of gut microbiota with diabetic nephropathy: a Mendelian randomization analysis

Background

Patients with DN (diabetic nephropathy) show remarkable variations in their gut microbiota composition. However, to date, no study has shown whether a causal relationship exists between gut microbiota composition and DN.

Methods

Here, we performed a two-sample Mendelian randomization (MR) investigation for identifying causal associations of gut microbiota with DN. Gut microbiota genetic data were gathered from the recent genome-wide association study pooled data of the MiBioGen consortium, which included 24 cohorts and 18,340 individuals.

Results

IVW(Inverse variance weighting) revealed that Verrucomicrobia [odds ratio (OR) = 1.390; 95% confidence interval (CI) = 1.10-1.75; p = 0.005], Peptostreptococcaceae (OR = 1.284; 95% CI = 1.03-1.59; p = 0.012), Verrucomicrobiaceae (OR = 1.390; 95% CI = 1.10-1.75; p = 0.005), Akkermansia (OR = 1.390; 95% CI = 1.10-1.75; p = 0.005), Butyricimonas (OR = 1.261; 95% CI = 1.02-1.55; p = 0.031), Catenibacterium (OR = 1.278; 95% CI = 1.02-1.59; p = 0.030).

Conclusion

Two-sample MR analysis identified 12 microbial taxa in gut microbiota (one of which is yet to be officially named) that showed significant causal associations with DN; 8 of these taxa significantly increased the risk of DN, while the remaining 4 taxa (including the one without an official name) reduced the risk of DN. The precise mechanisms influencing the interactions of gut microbiota with DN occurrence remain unclear; hence, additional investigations should be conducted to clarify these mechanisms.

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.

Coffee Leaf Tea Extracts Improve Hyperuricemia Nephropathy and Its Associated Negative Effect in Gut Microbiota and Amino Acid Metabolism in Rats

Hyperuricemia nephropathy (HN) is a metabolic disease characterized by tubular damage, tubulointerstitial fibrosis, and uric acid kidney stones and has been demonstrated to be associated with hyperuricemia. Coffee leaf tea is drunk as a functional beverage. However, its prevention effects on HN remain to be explored. This study showed that coffee leaf tea extracts (TE) contain 19 polyphenols, with a total content of 550.15 ± 27.58 mg GAE/g. TE decreased serum uric acid levels via inhibiting XOD activities and modulating the expression of urate transporters (GLUT9, OAT3, and ABCG2) in HN rats. TE prevented HN-induced liver and kidney damage and attenuated renal fibrosis. Moreover, it upregulated the abundance of SCFA-producing bacteria (Phascolarctobacterium, Alloprevotella, and Butyricicoccus) in the gut and reversed the amino acid-related metabolism disorder caused by HN. TE also decreased the circulating LPS and d-lactate levels and increased the fecal SCFA levels. This study supported the preliminary and indicative effect of coffee leaf tea in the prevention of hyperuricemia and HN.

Ameliorative Effect of Mannuronate Oligosaccharides on Hyperuricemic Mice via Promoting Uric Acid Excretion and Modulating Gut Microbiota

Mannuronate oligosaccharide (MOS) is α-D-mannuronic acid polymer with 1,4-glycosidic linkages that possesses beneficial biological properties. The aim of this study was to investigate the hypouricemic effect of MOS in hyperuricemic mice and demonstrate the possible protective mechanisms involved. In this research, 200 mg/kg/day of MOS was orally administered to hyperuricemic mice for four weeks. The results showed that the MOS treatment significantly reduced the serum uric acid (SUA) level from 176.4 ± 7.9 μmol/L to 135.7 ± 10.9 μmol/L (p < 0.05). MOS alleviated the inflammatory response in the kidney. Moreover, MOS promoted uric acid excretion by regulating the protein levels of renal GLUT9, URAT1 and intestinal GLUT9, ABCG2. MOS modulated the gut microbiota in hyperuricemic mice and decreased the levels of Tyzzerella. In addition, research using antibiotic-induced pseudo-sterile mice demonstrated that the gut microbiota played a crucial role in reducing elevated serum uric acid of MOS in mice. In conclusion, MOS may be a potential candidate for alleviating HUA symptoms and regulating gut microbiota.