Signaling pathways in uric acid homeostasis and gout: From pathogenesis to therapeutic interventions.

Uric acid is a product of purine degradation, and uric acid may have multiple physiologic roles, including the beneficial effects as an antioxidant and neuroprotector, maintenance of blood pressure during low salt ingestion, and modulation of immunity. However, overproduction of metabolic uric acid, and/or imbalance of renal uric acid secretion and reabsorption, and/or underexcretion of extrarenal uric acid, e.g. gut, will contribute to hyperuricemia, which is a common metabolic disease. Long-lasting hyperuricemia can induce the formation and deposition of monosodium urate (MSU) crystals within the joints and periarticular structures. MSU crystals further induce an acute, intensely painful, and sterile inflammation conditions named as gout by NLRP3 inflammasome-mediated cleavage of pro-IL-1ß to bioactive IL-1ß. Moreover, hyperuricemia and gout are associated with multiple cardiovascular and renal disorders, e.g., hypertension, myocardial infarction, stroke, obesity, hyperlipidemia, type 2 diabetes mellitus and chronic kidney disease. Although great efforts have been made by scientists of modern medicine, however, modern therapeutic strategies with a single target are difficult to exert long-term positive effects, and even some of these agents have severe adverse effects. The Chinese have used the ancient classic prescriptions of traditional Chinese medicine (TCM) to treat metabolic diseases, including gout, by multiple targets, for more than 2200 years. In this review, we discuss the current understanding of urate homeostasis, the pathogenesis of hyperuricemia and gout, and both modern medicine and TCM strategies for this commonly metabolic disorder. We hope these will provide the good references for treating hyperuricemia and gout.

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

BACKGROUND: Hyperuricemia (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. PURPOSE: Our 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. METHODS: Prescriptions 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. RESULTS: A 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. CONCLUSIONS: Our 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.

Whey Protein Peptide Pro-Glu-Trp Ameliorates Hyperuricemia by Enhancing Intestinal Uric Acid Excretion, Modulating the Gut Microbiota, and Protecting the Intestinal Barrier in Rats.

Hyperuricemia (HUA) is a metabolic disorder characterized by an increase in the concentrations of uric acid (UA) in the bloodstream, intricately linked to the onset and progression of numerous chronic diseases. The tripeptide Pro-Glu-Trp (PEW) was identified as a xanthine oxidase (XOD) inhibitory peptide derived from whey protein, which was previously shown to mitigate HUA by suppressing UA synthesis and enhancing renal UA excretion. However, the effects of PEW on the intestinal UA excretion pathway remain unclear. This study investigated the impact of PEW on alleviating HUA in rats from the perspective of intestinal UA transport, gut microbiota, and intestinal barrier. The results indicated that PEW inhibited the XOD activity in the serum, jejunum, and ileum, ameliorated intestinal morphology changes and oxidative stress, and upregulated the expression of ABCG2 and GLUT9 in the small intestine. PEW reversed gut microbiota dysbiosis by decreasing the abundance of harmful bacteria (e.g., Bacteroides, Alloprevotella, and Desulfovibrio) and increasing the abundance of beneficial microbes (e.g., Muribaculaceae, Lactobacillus, and Ruminococcus) and elevated the concentration of short-chain fatty acids. PEW upregulated the expression of occludin and ZO-1 and decreased serum IL-1ß, IL-6, and TNF-α levels. Our findings suggested that PEW supplementation ameliorated HUA by enhancing intestinal UA excretion, modulating the gut microbiota, and restoring the intestinal barrier function.

Antioxidant and Protective Effect of Ocimum basilicum Seeds Extract on Renal Toxicity Induced by Carbon Tetrachloride in Rats.

Basil (Ocimum basilicum L.) is distributed worldwide and used in the food, pharmaceutical, and cosmetic industries. Most applications are for the herb basil, recently the basil seeds have also been used commercially; however, little is known about the nutritional and functional properties of the seeds. The present study aimed to investigate a possible protective effect of the methanol extract of O. basilicum seeds (MEOB), based on its phytochemical content, against kidney toxicity induced by CCl4 in adult rats. A single dose of CCl4 was used to induce oxidative stress in rats, which was demonstrated by a significant rise of serum enzyme markers. MEOB was administrated for 15 consecutive days (200 mg/kg body weight) to Wistar rats before CCl4 treatment and the effects on serum urea, creatinine, and uric acid, as well as the kidney superoxide dismutase, catalase, glutathione peroxidase, and glutathione activity and thiobarbituric acid reactive substances and protein carbonyl (PCO) levels were evaluated. In addition, histopathological examinations of kidneys were performed. In the positive control group, CCl4 induced an increase in serum biochemical parameters and triggered oxidative stress in the kidney. MEOB (200 mg/kg BW) resulted in significant reduction of CCl4-elevated levels of kidney markers, urea and creatinine, and a significant increase of uric acid compared with the CCl4-only group. In addition, MEOB pretreatment resulted in a significant reduction in lipid peroxidation and PCO levels in renal tissue compared with CCl4-exposed group. MEOB definitely could prevent the development of pathological changes in the kidneys. Overall, we conclude that MEOB is effective in protecting renal function from CCl4 toxicity.

Possible role of pomegranate fruit in reversing renal damage in rats exposed to Phenylhydrazine.

Background: Pomegranate granatum (molasses and peels) and its constituents showed protective effects against natural toxins such as phenylhydrazine (PHZ) as well as chemical toxicants such as arsenic, diazinon, and carbon tetrachloride. Aim: The current study aimed to assess the effect of pomegranate molasses (PM), white peel extract, and red peel extract on nephrotoxicity induced by PHZ. Methods: 80 male rats were divided into eight equal groups; a control group, PM pure group, white peel pomegranate pure group, red peel pomegranate pure group, PHZ group, PM + PHZ group, white peel pomegranate + PHZ group and red peel pomegranate + PHZ group. Kidney function, inflammation markers, antioxidant activities, and renal tissue histopathology were investigated. Results: The results revealed that PHZ group showed a significant increase in lactate Dehydrogenase (LDH), malondialdehyde (MDA), creatinine, uric acid, BUNBUN, C - reactive protein (CRP), tumor necrosis factor, thiobarbituric acid reactive substances (TBARSs), and total antioxidant capacity (TAC) with a significant decrease of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) as compared with a control group. Other pomegranate-treated and PHZ co-treated groups with pomegranate showed a significant decrease of LDH, MDA, creatinine, uric acid, BUN, tumor necrosis factor, TBARSs, and TAC with a significant increase of CAT, GPx, and SOD as compared with PHZ group. Conclusion: Collectively, our data suggest that red, white peels, and molasses have anti-toxic and anti-inflammatory effects on renal function and tissues.

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.

Analysis of Correlation Between Serum Hypoxia-Inducible Factor-1α, Uric Acid, and Inflammatory Factor Levels and Lung Function in Patients with AECOPD.

Objective: To investigate the correlation between the serum hypoxia-inducible factor-1α, uric acid, inflammatory factor levels, and lung function in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods: The clinical data of patients with chronic obstructive pulmonary disease (40 cases) from March 2020 to March 2021 were retrospectively analyzed. According to the disease condition in patients with chronic obstructive pulmonary disease, they were divided into acute exacerbation stage (observation group, 20 cases) and stable stage (control group, 20 cases). All patients' basic data such as age, sex, and course of disease were collected and sorted out, and the serum hypoxia-inducible factor-1α, uric acid, inflammatory factor levels (procalcitonin, interleukin-6, and high-sensitivity C-reactive protein), and the index of their pulmonary function were measured. The profiles of serum hypoxia-inducible factor-1 alpha and uric acid, levels of inflammatory factors, and pulmonary function indices were measured and compared between the observation and control groups. The correlation between patients' serum hypoxia-inducible factor-1α, uric acid, and inflammatory factors and lung function was analyzed. Results: There was no difference in basic data between the observation group and the control group, P > .05. Serum hypoxia-inducible factor-1α, uric acid, and levels of inflammatory factors were all higher in the observation group than the control group, and the differences are significant (P < .05). There was significant difference in lung function indexes between the observation group and the control group (P < .05). Serum hypoxia-inducible factor-1α, uric acid, and inflammatory factor levels were negatively associated with pulmonary function indices. Conclusion: The more serious the condition of AECOPD patients is, the levels of serum hypoxia inducible factor -1α, uric acid and inflammatory factors gradually increase, and the lung function tends to decline.

Study on the mechanism of Orthosiphon aristatus (Blume) Miq. in the treatment of hyperuricemia by microbiome combined with metabonomics.

ETHNOPHARMACOLOGICAL RELEVANCE: Growing evidence indicates that hyperuricemia is closely associated with gut microbiota dysbiosis. Orthosiphon aristatus (Blume) Miq. (O. aristatus), as a traditional Chinese medicine, has been widely used to treat hyperuricemia in China. However, the mechanism by which O. aristatus treats hyperuricemia has not been clarified. AIM OF THE STUDY: In this study, we investigated whether the molecular mechanism underlying the anti-hyperuricemia effect of O. aristatus is related to the regulation of gut microbiota by 16S rDNA gene sequencing combined with widely targeted metabolomics. MATERIALS AND METHODS: Hyperuricemia was induced in rats by administration of 10% fructose and 20% yeast, and the uricosuric effect was assessed by measuring the uric acid (UA) levels in serum and cecal contents. Intestinal morphology was observed by hematoxylin and eosin (HE) staining. To explore the effects of O. aristatus on the gut microbiota and its metabolites, we utilized 16S rDNA gene sequencing combined with widely targeted metabolomics. Furthermore, metabolic pathway enrichment analysis was performed on the screened differential metabolites. The real time quantitative polymerase chain reaction (RT-PCR) and western blotting (WB) were used to detect the expression of relevant proteins in the key pathway. RESULTS: Our results indicated that O. aristatus intervention decreased serum UA levels and increased the UA levels in cecal contents in hyperuricemic rats. Additionally, O. aristatus improved intestinal morphology and altered the composition of the gut microbiota and its metabolites. Specifically, 16S rDNA revealed that O. aristatus treatment significantly reduced the abundance of unidentified-Ruminococcaceae and Lachnospiraceae-NK4A136-group. Meanwhile, widely targeted metabolomics showed that 17 metabolites, including lactose, 4-oxopentanoate and butyrate, were elevated, while 55 metabolites, such as flavin adenine dinucleotide and xanthine, were reduced. Metabolic pathway enrichment analysis found that O. aristatus was mainly involved in purine metabolism. Moreover, RT-PCR and WB suggested that O. aristatus could significantly up-regulate the expression of UA excretion transporter ATP-binding cassette subfamily G member 2 (ABCG2) in the intestine. CONCLUSION: O. aristatus exerts UA-lowering effect by regulating the gut microbiota and ABCG2 expression, indicating that this herb holds great promise in the treatment of hyperuricemia.

Shizhifang ameliorates pyroptosis of renal tubular epithelial cells in hyperuricemia through inhibiting NLRP3 inflammasome.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese Medicine (TCM) Compound Shizhifang (SZF), consisting of the seeds of four Chinese herbs, has been used in Shanghai Shuguang Hospital in China for more than 20 years and has proven its clinical safety and efficacy in lowering uric acid and protecting kidney function. AIM OF THE STUDY: Hyperuricemia (HUA)-induced pyroptosis of renal tubular epithelial cells serves as a significant cause of tubular damage. SZF proves to be effective in alleviating renal tubular injury and inflammation infiltration of HUA. However, the inhibiting effect of SZF on pyroptosis in HUA still remains elusive. This study aims to verify whether SZF could ameliorate pyroptosis in tubular cells induced by uric acid (UA). MATERIALS AND METHODS: Quality control analysis and chemical and metabolic identification for SZF and SZF drug serum were performed by using UPLC-Q-TOF-MS. In vitro, human renal tubular epithelial cells (HK-2) stimulated by UA were treated with SZF or NLRP3 inhibitor (MCC950). HUA mouse models were induced by intraperitoneal injection of potassium oxonate (PO). Mice were treated with SZF, allopurinol or MCC950. We focused on evaluated the effect of SZF on the NLRP3/Caspase-1/GSDMD pathway, renal function, pathologic structure and inflammation. RESULTS: SZF significantly restrained the activation of the NLRP3/Caspase-1/GSDMD pathway in vitro and in vivo induced by UA. SZF was better than allopurinol and MCC950 in reducing pro-inflammatory cytokine levels, attenuating tubular inflammatory injury, inhibiting interstitial fibrosis and tubular dilation, maintaining tubular epithelial cell function, and protecting kidney. Furthermore, 49 chemical compounds of SZF and 30 metabolites in serum after oral administration were identified. CONCLUSIONS: SZF inhibits UA-induced renal tubular epithelial cell pyroptosis via by targeting NLRP3 to inhibit tubular inflammatory and prevent the progression of HUA-induced renal injury effectively.

Anaerobic purinolytic enzymes enable dietary purine clearance by engineered gut bacteria.

Uric acid, the end product of purine degradation, causes hyperuricemia and gout, afflicting hundreds of millions of people. The debilitating effects of gout are exacerbated by dietary purine intake, and thus a potential therapeutic strategy is to enhance purine degradation in the gut microbiome. Aerobic purine degradation involves oxidative dearomatization of uric acid catalyzed by the O2-dependent uricase. The enzymes involved in purine degradation in strictly anaerobic bacteria remain unknown. Here we report the identification and characterization of these enzymes, which include four hydrolases belonging to different enzyme families, and a prenyl-flavin mononucleotide-dependent decarboxylase. Introduction of the first two hydrolases to Escherichia coli Nissle 1917 enabled its anaerobic growth on xanthine as the sole nitrogen source. Oral supplementation of these engineered probiotics ameliorated hyperuricemia in a Drosophila melanogaster model, including the formation of renal uric acid stones and a shortened lifespan, providing a route toward the development of purinolytic probiotics.

In vivo anti-hyperuricemia and anti-gouty arthritis effects of the ethanol extract from Amomumvillosum Lour.

The incidence of hyperuricemia and gout has been increasing year by year, and it is showing a younger trend. However, the first-line drugs currently used for hyperuricemia and gouty arthritis have serious side effects that limit their clinical application. Amomum villosum Lour. has been widely used in China for thousands of years as a traditional medical and edible plant, and previous screening showed that the ethanol extract of Amomum villosum Lour. could effectively inhibit the activity of xanthine oxidase. Based on this discovery, this paper had achieved in-depth mechanism research. The results showed that the ethanol extract of Amomum villosum Lour. could treat hyperuricemia by reducing the production of uric acid via inhibition of xanthine oxidase and increasing the excretion of uric acid via regulation of urate transporters. Meanwhile, the extract also showed a certain protective effect on hepatic and renal damage caused by hyperuricemia. With the formation of extensive uric acid, gouty arthritis will be induced by the deposition of monosodium urate in the joint. The extract could also relieve the inflammation by reducing the expression of inflammatory cytokines. In conclusion, the extract deserves focused research and development as a potential medicine, health care product or supplemented food for the prevention and treatment of hyperuricemia and gouty arthritis.

Lead exposure induced developmental nephrotoxicity in Japanese quail (Coturnix japonica) via oxidative stress-based PI3K/AKT pathway inhibition and NF-κB pathway activation.

Birds are sensitive to environmental pollution and lead (Pb) contamination could negatively affect nearly all avian organs and systems including kidney of excretive system. Thereby, we used a biological model species-Japanese quail (Coturnix japonica) to examine the nephrotoxic effects of Pb exposure and possible toxic mechanism of Pb on birds. Quail chicks of 7-day-old were exposed to 50 ppm Pb of low dose and high dose of 500 ppm and 1000 ppm Pb in drinking water for five weeks. The results showed that Pb exposure induced kidney weight increase while body weight and length reduction. The increase of uric acid (UA), creatinine (CREA) and cystatin c (Cys C) in the plasma suggested renal dysfunction. Moreover, both microstructural and ultrastructural changes demonstrated obvious kidney damages. In particular, renal tubule epithelial cells and glomeruli swelling indicated renal inflammation. Furthermore, changes in the content and activity of oxidative stress markers suggested that Pb caused excessive oxidative stress in the kidney. Pb exposure also induced abnormal apoptosis in the kidney. In addition, RNA sequencing (RNA-Seq) analysis revealed that Pb disturbed molecular pathways and signaling related with renal function. Especially, Pb exposure resulted in an increase in renal uric acid synthesis by disrupting purine metabolism. Pb caused apoptotic increment by inhibiting the phosphatidylinositol-3-kinase (PI3K)/RAC-alpha serine/threonine-protein kinase (AKT) pathway and induced aggravated inflammation by activating Nuclear Factor kappa B (NF-κB) signaling pathway. The study implied that Pb caused nephrotoxicity through structural damages, uric acid metabolism disorder, oxidation imbalance, apoptosis and inflammatory pathway activation.

Therapeutic effects of traditional Chinese medicine on gouty nephropathy: Based on NF-κB signalingpathways.

As the final product of purine metabolism, excess serum uric acid (SUA) aggravates the process of some metabolic diseases. SUA causes renal tubule damage, interstitial fibrosis, and glomerular hardening, leading to gouty nephropathy (GN). A growing number of investigations have shown that NF-κB mediated inflammation and oxidative stress have been directly involved in the pathogenesis of GN. Traditional Chinese medicine's treatment methods of GN have amassed a wealth of treatment experience. In this review, we first describe the mechanism of NF-κB signaling pathways in GN. Subsequently, we highlight traditional Chinese medicine that can treat GN through NF-κB pathways. Finally, commenting on promising candidate targets of herbal medicine for GN treatment via suppressing NF-κB signaling pathways was summarized.

Mechanisms of theaflavins against gout and strategies for improving the bioavailability.

BACKGROUND: Gout is a crystal related arthropathy caused by monosodium urate deposition. At present, the identification of appropriate treatments and new drugs to reduce serum uric acid levels and gout risk is a major research area. PURPOSE: Theaflavins are naturally occurring compounds characterized by a benzodiazepine skeleton. The significant benefits of theaflavins have been well documented. A large number of studies have been carried out and excellent anti-gout results have been achieved in recent years. STUDY DESIGN: A comprehensive analysis of the mechanism of the anti-gout effect of theaflavins is presented through a literature review and network pharmacology prediction, and strategies for increasing the bioavailability of theaflavins are summarized. METHODS: In this review, the active components and pharmacological mechanisms of theaflavins in the treatment of gout were summarized, and the relationship between theaflavins and gout, the relevant components, and the potential mechanisms of anti-gout action were clarified by reviewing the literature on the anti-gout effects of theaflavins and network pharmacology. RESULTS: Theaflavins exert anti-gout effects by down regulating the gene and protein expression of glucose transporter 9 (GLUT9) and uric acid transporter 1 (URAT1), while upregulating the mRNA expression levels of organic anion transporter 1 (OAT1), organic cation transporter N1 (OCTN1), organic cation transporters 1/2 (Oct1/2), and organic anion transporter 2 (OAT2). Network pharmacology prediction indicate that theaflavins can regulate the AGE-RAGE and cancer signaling pathways through ATP-binding cassette subfamily B member 1 (ABCB1), recombinant mitogen activated protein kinase 14 (MAPK14), telomerase reverse tranase (TERT), signal transducer and activator of transcription 1 (STAT1), matrix metalloproteinase 2 (MMP2), B-cell lymphoma-2 (BCL2), and matrix metalloproteinase 14 (MMP14) targets for anti-gout effects. CONCLUSION: This review presents the mechanisms of anti-gout action of theaflavins and strategies for improving the bioavailability of theaflavins, as well as providing research strategies for anti-gout treatment measures and the development of novel anti-gout drugs.

Comparative analysis of biochemical, hormonal, and mineral compositions of preovulatory and cystic ovarian follicles in buffalo during the non-breeding season.

This study is a comparative analysis of the biochemical, hormonal, and mineral compositions of follicular fluid in preovulatory and cystic follicles of water buffalo (Bubalus bubalis). In total, reproductive tracts from 215 buffalo along with intact ovaries were collected randomly from an abattoir. The incidence of cystic conditions found in this study was 3.72% (8/215), involving the right ovary in 62.5% of instances and the left ovary in 37.5% of instances during the non-breeding season. Follicular fluid was aspirated from preovulatory follicles (12-15 mm diameter, oestrogen-active, follicular phase or stage IV corpus luteum on one of the two ovaries, n = 10) and cystic follicles (at least 20 mm diameter, no corpus luteum on any one of the two ovaries, n = 8). The follicular fluid samples were assayed for biochemical components (uric acid, creatinine, blood urea nitrogen, cholesterol, total protein, glucose, ascorbic acid, and alkaline phosphatase), hormones (progesterone, estradiol, and insulin), and minerals (calcium, magnesium, phosphorus, copper, zinc, and cobalt). Cystic follicles had greater (P < 0.05) concentrations of creatinine, blood urea nitrogen, cholesterol, progesterone, copper, zinc, and cobalt, and lesser (P < 0.05) concentrations of uric acid, glucose, ascorbic acid, estradiol, insulin, calcium, magnesium, and phosphorus compared with preovulatory follicles. These results indicated the marked differences in follicular fluid composition between preovulatory and cystic follicles in buffalo. Some of the changes were indicative of oxidative stress and disturbed steroidogenesis, two important mechanisms shown to be associated with cystic ovarian disease in various species. Further studies are warranted to investigate whether these differences are directly or indirectly involved in the formation of cystic follicles or are mere manifestations of the condition.

Diallyl trisulfide inhibits monosodium urate-induced NLRP3 inflammasome activation via NOX3/4-dependent mitochondrial oxidative stress in RAW 264.7 and bone marrow-derived macrophages.

BACKGROUND: Monosodium urate (MSU) crystals are associated with gouty inflammatory diseases. MSU-associated inflammation is majorly triggered by NOD-like receptor protein 3 (NLRP3) inflammasome that promotes interleukin (IL)-1ß secretion. Although diallyl trisulfide (DATS) is well-known polysulfide garlic compounds with anti-inflammatory effects, its action in MSU-induced inflammasome activation has not been known yet. PURPOSE: The objective of the current study was to investigate anti-inflammasome effects and mechanisms of DATS in RAW 264.7 and bone marrow-derived macrophages (BMDM). METHODS: The concentrations of IL-1ß were analyzed with enzyme-linked immunosorbent assay. The MSU-induced mitochondrial damage and reactive oxygen species (ROS) production were detected by fluorescence microscope and flow cytometry. The protein expressions of NLRP3 signaling molecules, NADPH oxidase (NOX) 3/4 were assessed with Western blotting. RESULTS: DATS suppressed MSU-induced IL-1ß and caspase-1 accompanied by decreased inflammasome complex formation in RAW 264.7 and BMDM. In addition, DATS restored mitochondrial damage. DATS downregulated NOX 3/4 that were upregulated by MSU as predicted by gene microarray and confirmed by Western blotting. CONCLUSION: This study first reports mechanistic finding that DATS alleviates MSU-induced NLRP3 inflammasome by mediating NOX3/4-dependent mitochondrial ROS production in macrophages in vitro and ex vivo, suggesting DATS could be effective therapeutic candidate for gouty inflammatory condition.

Naringenin Ameliorates Hyperuricemia by Regulating Renal Uric Acid Excretion via the PI3K/AKT Signaling Pathway and Renal Inflammation through the NF-κB Signaling Pathway.

Hyperuricemia characterized by high serum levels of uric acid (UA, >6.8 mg/dL) is regarded as a common chronic metabolic disease. When used as a food supplement, naringenin might have various pharmacological activities, including antioxidant, free-radical-scavenging, and inflammation-suppressing activities. However, the effects of naringenin on hyperuricemia and renal inflammation and the underlying mechanisms remain to be elucidated. Here, we comprehensively examined the effects of naringenin on hyperuricemia and the attenuation of renal impairment. Mice were injected with 250 mg/kg of potassium oxonate (PO) and given 5% fructose water to induce hyperuricemia. The pharmacological effects of naringenin (10 and 50 mg/kg) and benzbromarone (positive control group, 20 mg/kg) on hyperuricemic mice were evaluated in vivo. The disordered expression of urate transporters in HK-2 cells was stimulated by 8 mg/dL UA, which was used to determine the mechanisms underlying the effects of naringenin in vitro. Naringenin markedly reduced the serum UA level in a dose-dependent manner and improved renal dysfunction. Moreover, the increased elimination of UA in urine showed that the effects of naringenin were associated with the regulation of renal excretion. Further examination indicated that naringenin reduced the expression of GLUT9 by inhibiting the PI3K/AKT signaling pathway and reinforced the expression of ABCG2 by increasing the abundance of PDZK1 in vivo and in vitro. Furthermore, sirius red staining and western blotting indicated that naringenin plays a protective role in renal injury by suppressing increases in the levels of pro-inflammatory cytokines, including IL-6 and TNF-α, which contribute to the inhibition of the TLR4/NF-κB signaling pathway in vivo and in vitro. Naringenin supplementation might be a potential therapeutic strategy to ameliorate hyperuricemia by promoting UA excretion in the kidney and attenuating the inflammatory response by decreasing the release of inflammatory cytokines. This study shows that naringenin could be used as a functional food or dietary supplement for hyperuricemia prevention and treatment.

Anti-urolithiatic Activity of Daidzin in Ethylene Glycol-Induced Urolithiasis in Rats.

Urolithiasis is a common urological disorder, which causes considerable morbidity in both genders at all age groups worldwide. Though treatment options such as diuretics and non-invasive techniques to disintegrate the deposits are available, but often they are found less effective in the clinics. In this work, we planned to investigate the ameliorative effects of daidzin against the ethylene glycol (EG)-induced urolithiasis in rats. The male albino rats were distributed into four groups (n = 6) as control (group I), urolithiasis induced by the administration of 0.75% EG (group II), urolithiasis induced rats treated with 50 mg/kg of daidzin (group III), and urolithiasis rats treated with standard drug 750 mg/kg of cystone (group IV). The urine volume, pH, and total protein in the urine were assessed. The activities of marker enzymes in both plasma and kidney tissues were analyzed using assay kits. The levels of kidney function markers such as calcium, oxalate, urea, creatinine, uric acid, magnesium, BUN, and phosphorous were estimated using assay kits. The status of antioxidants and inflammatory cytokines were also examined using kits. The renal tissues were examined by histopathological analysis. Our results revealed that the daidzin treatment effectively decreased the urine pH and protein level and increased the urine volume in the urolithiasis rats. Daidzin decreased the calcium, oxalate, uric acid, and urea, creatinine, and BUN levels and also improved the magnesium and phosphorus in the urolithiasis rats. The activities of AST, ALT, ALP, GGT, and LDH were effectively reduced by the daidzin in both serum and renal tissue. Daidzin also reduced the inflammatory marker and increased the antioxidant levels. Histopathology results also proved the therapeutic effects of daidzin. Together, our results displayed that daidzin is effective in the amelioration of EG-induced urolithiasis in rats.

Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway: An in vitro Study.

OBJECTIVE: To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino (TSDN) on the arachidonic acid pathway in monosodium urate (MSU) crystal-induced M1-polarized macrophages. METHODS: M1 polarization of RAW264.7 cells were induced by 1 µ g/mL lipopolysaccharide (LPS). The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN. MSU (500 µ g/mL) was used to induce the gouty arthritis model. Afterwards, 10 µ g/L TSDN and 8 µ mol/L celecoxib, which was used as a positive control, were added to the above LPS and MSU-induced cells for 24 h. The mRNA and protein expressions of cyclooxygenase (COX) 2, 5-lipoxygenase (5-LOX), microsomal prostaglandin E synthase derived eicosanoids (mPGES)-1, leukotriene B (LTB)4, cytochrome P450 (CYP) 4A, and prostaglandin E2 (PGE2) were tested by real-time polymerase chain reaction and Western blotting, respectively. The enzyme-linked immunosorbent assay was used to test the contents of M1 markers, including inducible nitric oxid synthase (NOS) 2, CD80, and CD86. RESULTS: TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2, 5-LOX, CYP4A, LTB4, and PGE2 (P<0.01) while increased the mRNA and protein expression of mPGES-1 (P<0.05 or P<0.01). TSDN could also significantly decrease the contents of NOS2, CD80, and CD86 (P<0.01). CONCLUSION: TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Multi-omics analysis reveals therapeutic effects of Bacillus subtilis-fermented Astragalus membranaceus in hyperuricemia via modulation of gut microbiota.

At present, uncovering how to preventandcontrol hyperuricemia has become an important public health issue. Fermented traditionalChinesemedicine has exhibited promising applications in the clinical management of hyperuricemia. In this study, we generated a hyperuricemic mouse model to explore the potent therapeutic ability of Bacillus subtilis-fermented Astragalus membranaceus (BFA) on this condition by multi-omics analysis. We found that the serum uric acid level was decreased in hyperuricemic mice after BFA treatment. BFA effectively attenuated renal inflammation and regulated the expression of urate transporters. Additionally, we found that BFA could increase the abundances of butyrate-producing bacteria, including Butyricimonas synergistica, Odoribacter splanchnicus, and Collinsella tanakaei, and probiotics, including Lactobacillus intestinalis and Bacillus mycoides, in hyperuricemic mice. Therefore, we believe that BFA has the potential to become a novel safe and valid functional food for addressing hyperuricemia.