Urate-lowering and renal-protective effects of sugarcane polyphenols in hyperuricemia: mechanisms and key components

Abstract

Hyperuricemia (HUA) is a metabolic disorder characterized by abnormally elevated levels of uric acid (UA) in the blood, often accompanied by renal damage. The continuous rise in HUA incidence necessitates the development of safe, efficient natural urate-lowering pathways. This study combined network pharmacology prediction with rat model experiments to systematically evaluate the urate-lowering potential of sugarcane polyphenols (SP), a byproduct of the sugarcane sugar industry. The results showed that the intake of low, medium, and high doses of SP significantly reduced the serum UA levels in HUA rats to 19.77%, 27.42%, and 45.54%, respectively. Moreover, SP significantly improved liver and kidney function damage, as evidenced by reduced levels of blood urea nitrogen (BUN), creatinine (CRE), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Mechanistic studies revealed that SP regulates UA metabolism through two distinct mechanisms: reducing production and promoting excretion. Specifically, SP inhibited hepatic xanthine oxidase (XOR) activity, thereby reducing UA synthesis. Concurrently, SP enhanced UA excretion by upregulating the expression of ATP-binding cassette subfamily G member 2(ABCG2) and downregulating the expression of urate transporter 1(URAT1) and glucose transporter 9(GLUT9). When the total phenolic content was equivalent to SP, the chlorogenic acid (CGA) group showed urate-lowering activity similar to that of SP. This suggests that CGA may play an essential role in the ability of SP to reduce UA. Additionally, SP inhibited inflammation-related molecule expression and improved histopathological changes in the kidneys of HUA rats by affecting the PI3K/AKT/NF-κB signaling pathway, further substantiating the renal protective effects of SP in HUA conditions. The results of this study provide a theoretical basis for the in vivo urate-lowering activity of SP rich in CGA and its alleviation of renal damage. This may offer theoretical references for the comprehensive utilization of SP, a byproduct of the sugarcane sugar industry, laying the foundation for the high-value utilization of sugarcane byproducts and the development of polyphenol functional activity products.

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1. Introduction

Sugarcane is an important economic crop widely cultivated around the world, including in countries such as Brazil, India, and China. It serves as the primary global source of edible sugar (approximately 70%). It is estimated that global sugarcane production exceeds 1.7 billion metric tons annually, of which approximately 20%–30% of the byproducts remain underutilized, thereby awaiting the development of high-value-added products.¹ Traditional sugar-making processes involve crushing sugarcane stalks to obtain sugarcane juice, which is sterilized and clarified to produce a thin liquid. This thin juice is subsequently concentrated through repeated evaporation to form sugarcane massecuite. Crystallization seeds are added to the massecuite to induce sugar crystallization, after which the crystals are separated via centrifugation to obtain a high-purity precursor of refined sugar. The supernatant after centrifugation, known as sugarcane molasses, is rich in bioactive substances such as polyphenols and amino acids, indicating significant potential for further development and utilization.^2–4 Sugarcane polyphenols (SP) are obtained via the solvent extraction, filtration, vacuum concentration, and ion exchange of sugarcane molasses, representing an effective approach for the high-value utilization of sugarcane byproducts.⁵ The various physiological functions of SP have been verified through in vitro and animal experiments. For example, molasses polyphenol extract significantly reduces the levels of oxidative stress marker malondialdehyde and pro-inflammatory factors IL-6 and TNF-α by scavenging DPPH and ABTS free radicals (EC₅₀ = 0.12 mg mL⁻¹) and simultaneously inhibiting the NF-κB inflammatory signaling pathway.⁵

Hyperuricemia (HUA) is a metabolic disorder characterized by abnormally elevated serum uric acid (SUA) levels due to the excessive production or impaired excretion of uric acid (UA) (typically defined as serum UA ≥ 420 μmol L⁻¹ on two separate occasions). The global HUA incidence rate is rising and is often accompanied by joint and kidney damage. Excessively high urate concentrations promote sodium urate crystal deposition in joints, soft tissues, and kidneys, triggering acute inflammation and severe pain, known as gout. As the condition progresses, UA deposition in the kidneys can lead to urate nephropathy and urolithiasis and may result in renal failure and death in severe cases.⁶ Additionally, HUA is a potential risk factor for various metabolic diseases, including gout, hypertension, diabetes, and coronary heart disease.^7,8 HUA and renal inflammation exhibit a close, complex bidirectional relationship, manifesting as a vicious cycle of mutual exacerbation: elevated UA levels lead to urate crystal deposition, which activates local renal inflammatory responses, releases inflammatory factors, and intensifies tissue damage. The pathological changes caused by renal inflammation impair the ability of the kidneys to excrete UA, further increasing serum UA levels, which in turn exacerbate the renal inflammatory response.^9–11 Therefore, it is crucial for intervention strategies to simultaneously focus on regulating UA metabolism and inflammatory pathways. The rising incidence of HUA necessitates effective prevention and control approaches to enhance global health.^12,13 Drugs that inhibit UA production (such as allopurinol and febuxostat) or promote UA excretion (such as benzbromarone) are commonly used in clinical practice to manage serum UA levels.⁶ However, the long-term use of these medications can increase the risk of liver and kidney damage as well as cause hypersensitivity reactions. Additionally, surveys indicate that a low proportion of gout patients receive standardized UA-lowering treatment, and adherence to such treatments is poor.¹⁴ These issues have intensified the need to explore safe, effective natural substances for reducing UA.

Previous studies have analyzed SP using HPLC-MS/MS to identify their polyphenolic composition, revealing that chlorogenic acid (CGA) is a characteristic component with a content of 146.38 μg g⁻¹. Investigations into the antiglycation activity of SP have shown that CGA contributes significantly to this activity.¹⁵ CGA, a phenolic acid derived from caffeic and quinic acid, exhibits antioxidant, anti-inflammatory, and neuroprotective biological activities, offering broad application prospects and health benefits.^16,17 Previous studies have demonstrated that CGA displays potential for reducing UA levels: CGA has shown UA-lowering activity in rat and mouse models.^18,19 Additionally, research has confirmed that CGA can alleviate the inflammation symptoms induced by sodium urate crystals.²⁰ Nuclear magnetic resonance spectroscopy (NMR) has identified CGA and its isomers in Cichorium intybus L. extracts, which have also exhibited good UA-lowering activity in mouse models, with CGA being the substance basis for the activity of the extract.²¹ Similarly, this provides a basis for speculating that SP, characterized by CGA, may lower UA levels.

Therefore, this study utilizes a HUA rat model to systematically investigate the urate-lowering effect and potential mechanisms of SP, using CGA as a control group. This research focuses on UA production, UA excretion, and HUA-induced damage to the body while aiming to confirm the impact of SP on SUA levels in HUA conditions. It also examines the ability of SP to improve liver and kidney function and renal inflammation. Furthermore, this study explores the impact of SP regulation on the expression of the key enzymes involved in UA production and UA transport proteins in renal tissues. It aims to provide a theoretical basis for intervention with SP, promote the reuse of byproducts during sugar production from sugarcane, and enhance the development potential of SP-related functional products.

2. Materials and methods

2.1 Materials

The Product Makers Co., Ltd (Shanghai, China) provided the SP (Phytolin®), a bioactive natural substance extracted from sugarcane molasses, a byproduct of sugar production from sugarcane. The SP exhibited a total phenolic content of 18 mg gallic acid equivalents per mL and a total flavonoid level of 4.2 mg catechin equivalents per mL. Previous studies employed HPLC-MS/MS analysis to identify the polyphenol composition of SP, which mainly consisted of 32 polyphenolic compounds, including CGA, p-coumaric acid, vanillin, syringic acid, and caffeic acid. CGA represented the characteristic component, with a content of 146.38 μg g⁻¹.¹⁵

The hypoxanthine (HX) (≥99%, reagent grade), RIPA lysis buffer, phenylmethanesulfonyl fluoride, TBST, ECL hypersensitive chemiluminescent substrate, PI3 kinase p85α, phospho-PI3K P85α/β/P55γ, and phospho-NF-κB p65 (Ser536) polyclonal antibody were purchased from Beyotime Biotechnology Co. Ltd (Shanghai, China), while the potassium oxonate (PO) (BR, 98%) was supplied by Yuanye Bio-Technology Co. Ltd (Shanghai, China). The carboxymethylcellulose sodium (CMC-Na), CGA (≥98%), and SDS-PAGE loading buffer were obtained from Beijing Solarbio Technology Co. Ltd (Beijing, China). The polyvinylidene fluoride (PVDF) membranes (0.45 μm) were purchased from Merck. The URAT1, GLUT9, ABCG2, and NFκB p65 polyclonal antibodies were supplied by Proteintech (Wuhan, China), while the AKT and phospho-AKT (Ser473) polyclonal antibodies were purchased from Zenbio (Chengdu, China).

2.2 The potential SP targets and specific HUA disease targets

Previous studies identified 32 SP components, including CGA, p-coumaric acid, vanillin, syringic acid, caffeic acid, homoorientin, vitexin, swertisin, diosmin, naringenin, quercetin, rutin, isorhamnetin, catechin gallate, tricin, biochanin A, umbelliferone, 5,4′-dihydroxy-3,3′-dimethoxy-6,7-methylenedioxyflavone 4′-O-glucuronide, apigenin 7-O-glucuronide, hispidulin, isoquercetin, psoralen, (−)-Epigallocatechin, rriodictyol, procyanidin trimer C1, 7,3′,4′-trihydroxyflavone, 6′′-O-malonylglycitin, theaflavin 3′-O-gallate, myricetin, pinocembrin, peonidin, and delphinidin 3-O-(6′′-acetyl-galactoside). The potential action targets of the 32 SP components were searched using the SwissTargetPrediction platform (https://www.swisstargetprediction.ch/). The results were consolidated to eliminate duplicates and identify the potential SP action targets. Then, “hyperuricemia” was utilized as the keyword to conduct searches in the GeneCards database (https://www.genecards.org/) and OMIM database (https://omim.org/). The results were standardized, and duplicates were removed using Uniprot (https://www.uniprot.org/) to obtain the HUA disease-specific targets, which were intersected with the potential SP action targets using an online Venn diagram tool (https://bioinformatics.psb.ugent.be/webtools/Venn/) to identify the intersection targets.

2.3 Construction of the protein–protein interaction (PPI) network and selection of the core targets

The intersection targets were entered into the STRING database (https://cn.string-db.org/) to construct a PPI network, selecting “Homo sapiens” as the species. The PPI network was imported into Cytoscape 3.7.2 software (https://cytoscape.org/) for visualization analysis, allowing for the construction of a compound-target–disease network diagram. The Centiscape 2.2 plugin was utilized to filter the core targets using the “Betweenness unDir”, “Closeness unDir”, and “Degree unDir” functions.

2.4 Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis

The DAVID platform (https://david.ncifcrf.gov/) was employed for GO analysis of the intersection targets, focusing on the enrichment of the biological processes (BP), molecular function (MF), and cellular components (CC). Additionally, KEGG enrichment analysis was performed. Results with P-values and false discovery rates (FDR) below 0.05 were selected for the graphic representation of the highly enriched outcomes.

2.5 Animal and experimental design

Six-to-eight-week-old male SPF-grade Sprague Dawley rats weighing 200 ± 20 g were purchased from Vital River Laboratories (Beijing, China), with the license number SCXK (Jing) 2021-0006. All rats were accommodated in standardized environmental conditions at a temperature of 22–24 °C, a relative humidity of 50–60%, and a 12 h light–dark cycle, and had free access to standard chow and water. The rats were acclimatized for one week and randomly divided into seven groups (n = 8): Normal group (Normal), Sample Control group, Model group (Model), Low-Dose Sugarcane Polyphenol group (SPL), Medium-Dose Sugarcane Polyphenol group (SPM), High-Dose Sugarcane Polyphenol group (SPH), and Chlorogenic Acid group (CGA group). All the rats were weighed at 3-day intervals.

2.6 Intervention with SP and the establishment of the HUA model

The rats were subjected to a two-week intervention with SP using a method delineated by Wang et al.¹⁵ The recommended daily SP intake level (10 g per day, https://www.nhc.gov.cn/sps/s7892/202205/7777634cb5994c308e12cf3a3255c622.shtml) was converted into a feeding quantity for rats. The SP gavage doses for the sample treatment groups were 0.257 mg SP per g BW per day for the SPL group, 0.514 mg SP per g BW per day for the SPM group, and 1.028 mg SP per g BW per day for the SPH group. The Sample Control group received 1.028 mg SP per g BW per day. The total phenol content of the CGA group was the same as the SPH group (same phenolic level), which is 20.272 μg g⁻¹ BW per day. All other groups were given an equal volume of ultrapure water daily.

After a two-week pre-gavage period, HUA model induction was initiated by orally administering a combination of 500 mg kg⁻¹ PO and 300 mg kg⁻¹ HX. The model-inducing agents were dissolved in 0.5% CMC-Na and administered orally 2 h after daily intervention. The Normal and Sample Control groups were gavaged with an equivalent volume of 0.5% CMC-Na.

At the end of the experiment, feces and urine were collected from the rats for subsequent analysis. After the final gavage of the model-inducing drugs and SP, the rats were fasted for 10 h and then euthanized. Blood was collected from the abdominal aorta, and the liver, kidneys, and small intestine were harvested. The plasma was allowed to stand at room temperature for 1 h and then centrifuged at 3500 rpm for 10 min to obtain the serum. One kidney and the ileum were placed in formalin for fixation to prepare the histological sections. The remaining organs were quickly frozen in liquid nitrogen and stored at −80 °C for subsequent biochemical analysis.

This experimental protocol complies with animal welfare and ethical requirements and was approved by the Animal Ethics Committee of Pony Testing International Group Co. Ltd (PONY-2023-FL-22).

2.7 Measurement of the physiological and biochemical parameters materials

Commercial kits (Nanjing Jiancheng, China) were used to measure the UA, BUN, CRE, ALT, and AST levels in the rat serum, as well as the UA levels in the urine and feces. Based on the CRE results, the estimated glomerular filtration rate (eGFR) was calculated by referring to the CKD-EPI equation.²² A portion of the rat liver was homogenized in nine volumes of 0.01 M PBS. The homogenate was centrifuged at 4 °C and 12 000 rpm for 10 min to obtain the supernatant, which was used for xanthine oxidase activity determination after protein concentration correction in each sample. The rat kidneys were used to prepare tissue homogenates, and the supernatant was collected after centrifugation. The interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels in the kidney tissue were measured using enzyme-linked immunosorbent assays (Lianke, Hangzhou).

2.8 Histopathological analysis

The rat kidneys and ileal tissues were fixed in paraformaldehyde for 48 h, dehydrated, permeabilized, and embedded in paraffin blocks. The paraffin sections were subjected to hematoxylin–eosin (H&E) staining, after which the slides were sealed. The tissue structures were observed using an inverted microscope.

2.9 Western blot (WB)

Appropriate quantities of the rat tissue were collected, washed with PBS, and homogenized in five volumes of RIPA lysis buffer containing PMSF and phosphatase inhibitors to prepare the tissue homogenates. The homogenates were lysed on ice for 30 min and centrifuged at 4 °C and 12 000 rpm for 10 min to obtain the supernatant. After determining and normalizing the protein concentration, 5× loading buffer was added, and the samples were denatured. The proteins in the samples were separated via 10% SDS-PAGE electrophoresis and transferred to a PVDF membrane. The membrane was blocked with 5% skim milk at room temperature for 2 h, followed by incubation with polyclonal antibodies against URAT1 (1 : 1500), ABCG2 (1 : 1000), GLUT9 (1 : 1000), PI3K (1 : 1000), p-PI3K (1 : 1000), AKT (1 : 1000), p-AKT (1 : 1000), NF-κB (1 : 3000), p-NF-κB (1 : 1000), and GAPDH (1 : 1000). After incubation with the secondary antibodies, the protein bands were detected using an ECL luminescent solution. The grayscale values were measured using the Image J software to quantify the protein expression.

2.10 Data analysis

All data were presented as mean ± standard error. The data were analyzed using one-way analysis of variance (ANOVA) followed by Duncan's multiple range test (SPSS 23.0). Graphing software was used to plot the results, with a significance set as P < 0.05.

3. Results

3.1 Prediction of the SP targets

A predictive analysis of the urate-lowering SP targets was performed based on the principles of systems biology. The potential targets of the 32 SP components were searched in the SwissTargetPrediction database, yielding a total of 307 potential targets after merging and removing duplicates. Disease-specific targets were identified by searching the GeneCards and OMIM databases using the keyword “hyperuricemia”, resulting in 1219 disease targets after merging and removing duplicates. Sixty-three proteins were identified in the intersection of the potential SP targets and HUA disease-specific targets, indicating that SP might exhibit HUA therapeutic potential (Fig. 1A).

Fig. 1 The predicted Targets of SP on Hyperuricemia (HUA). (A) The Venn diagram of the intersection targets between the SP and HUA. (B) The PPI network of the intersecting targets and the selection of core targets. (C) The PPI network of the core targets. A larger area and darker color of a target indicate a higher degree value, indicating more direct interactions with other targets and a greater influence within the PPI network, showing a more critical role in the SP modulation of HUA. (D) The compound–target–pathway network. The two exterior blue ellipses represent the 63 intersecting targets derived from SP and HUA, with the 16 interior blue ellipses signifying the core targets. The green polygons represent the 32 polyphenolic components identified in SP, with larger areas indicating higher degree values, signifying more direct interactions with the intersecting targets and a more critical role in the SP regulatory effect on HUA.

The PPI network diagram (Fig. 1B) shows the interaction between the 63 potential targets, consisting of 63 nodes and 776 edges. To identify key regulatory targets, the network was analyzed using the Centiscape 2.2 plugin in Cytoscape. Topological parameters were calculated, and the degree value—representing the number of direct interactions each node has—was used as the primary criterion for hub gene selection. The top 16 targets with the highest degree values were defined as core targets, forming a subnetwork of 16 nodes and 172 edges (Fig. 1C). These hub proteins are considered functionally significant in the SP-mediated regulation of hyperuricemia due to their central positions within the network.

These core targets collectively participate in multiple critical biological pathways, with particularly prominent roles in uric acid metabolism and inflammatory responses. AKR1B1, XDH, ABCG2, MAOA, and MAOB are implicated in metabolic regulation, where XDH and ABCG2 specifically regulate uric acid production and excretion. TLR4, PTGS2, NFKB1, and TNF primarily mediate inflammatory cascades. Additional targets—including BCL2, CDK4, PPARG, SIRT1, ESR1, NFE2L2, and SERPINE1—are involved in pathological processes that are triggered or aggravated by hyperuricemia, including oxidative stress, apoptosis, renal fibrosis, hormonal dysregulation, and metabolic imbalance. Specifically, these processes are mediated through oxidative stress regulation (NFE2L2, SIRT1), apoptosis (BCL2), fibrosis and endothelial dysfunction (SERPINE1), hormonal modulation of urate transport (ESR1), and metabolic or cell cycle dysregulation (PPARG, CDK4).

The SP components and their targets were visualized in a compound–target–pathway network diagram (Fig. 1D), illustrating the multi-component, multi-target characteristics of SP.

3.2 Enrichment analysis of the related pathways and the biological process

The 63 intersecting targets were subjected to GO enrichment analysis, yielding 78 BPs, 11 CCs, and 20 MFs. Fig. 2A displays bubble charts of the top ten terms in each of the three categories. SP may improve HUA by modulating a variety of BPs, including transcriptional regulation, signal transduction, cell proliferation, and immune responses. The SP improvement targets in HUA primarily included CCs such as cytosol, the cytoplasm, and the cell membrane. The most likely MFs involved in the SP improvement of HUA included identical protein binding, ATP binding, protein homodimerization, and enzyme binding.

Fig. 2 Enrichment analysis of the potential SP targets in HUA. (A) A bubble chart of the GO enrichment for BP, CC, and MF. (B) A bar chart of the KEGG pathway enrichment.

Fig. 2B shows the KEGG pathway analysis results. “Metabolic pathways” showed the highest degree of enrichment (n = 20), indicating that the regulation of HUA by SP likely involved the expression of proteins related to metabolism. Furthermore, the KEGG results revealed that several pathways were associated with the improvement of HUA, including the PI3K-Akt, AMPK, NF-κB, and HIF-1 signaling pathways. The PI3K-Akt signaling pathway displayed the highest degree of enrichment (n = 13), suggesting its significance in the SP amelioration of HUA, warranting further research into this signaling pathway. The enrichment of pathways related to human diseases (in purple) indicated that the improvement of HUA by SP might be associated with cancer development and the enhancement of related metabolic diseases.

3.3 The effect of SP and CGA on the basic indicators and UA levels in HUA rats

Fig. 3A shows the animal experimental procedure. Fig. 3B illustrates the body weight changes of the rats in each group throughout the experiment. No significant differences were evident in the weight gain of the rats during the intervention period, while weight gain slowed during the modeling period. The organ index, a direct indicator of the physiological damage in the rats (Fig. 3C), showed no significant differences between the kidney indices of the Sample Control and Normal groups, indicating that SP ingestion alone caused no harm to the rats. The kidney index of the Model group was significantly higher than that of the Normal group (P < 0.05), indicating pathological changes in the rat kidneys in HUA conditions induced by HX + PO. However, the kidney index declined after SP or CGA intervention.

Fig. 3 The effect of SP and CGA on the basic indicators and UA levels in HUA rats. (A) The experimental design for the rats. (B) The changes in the body weights of the rats. (C) Kidney index. (D) Serum UA. (E) Urine UA. (F) Fecal UA. The data are presented as mean ± SD (n = 8). Different letters between the groups indicate statistically significant differences (P < 0.05).

Fig. 3D shows the serum UA levels of the rats in each group. After 16 days of modeling with HX + PO, the SUA level of the Model group was 4.91-fold higher than in the Normal group (P < 0.01), indicating the successful establishment of the HUA model. Compared with the Model group, the UA levels in the SP intervention groups (0.257, 0.514, and 1.028 mg SP per g BW per d) and the CGA treatment group reduced by 54.46% (77.80 ± 19.37 μmol L⁻¹), 72.58% (46.84 ± 15.97 μmol L⁻¹), 80.23% (33.78 ± 9.83 μmol L⁻¹), and 69.34% (52.37 ± 13.57 μmol L⁻¹), respectively, with statistically significant differences (P < 0.05). The SUA levels of the SPM and SPH groups returned to levels similar to the Normal group, indicating that supplementation with SP effectively alleviated HUA. The main component, CGA, reduced the urate activity, which was consistent with the findings of Zhou et al.¹⁸ Notably, at the same phenolic level, the serum UA of the rats in the SPH group was significantly lower than those in the CGA group (P < 0.05), suggesting that the urate-lowering activity of the SP mixture exceeded that of CGA.

UA was detected in the rat urine and feces since two-thirds of UA was excreted by the kidneys and one-third by the intestines (Fig. 3E and F). The urine UA level was significantly higher in the Model group (P < 0.05) than in the Normal group. The urine UA levels of the CGA group and SP intervention groups (SPL, SPM, and SPH) showed no significant differences from the Model group (P < 0.05), indicating that SP intervention increased the UA excretion in the kidneys. The fecal UA level was considerably higher in the Model group than in the Normal group (P < 0.05). However, no significant differences were evident between the fecal UA levels of the treatment and Normal groups.

3.4 SP and CGA alleviate liver and kidney function damage in HUA rats

Since the kidneys are crucial for UA excretion, a decline in renal function can impact this ability in the body. CRE and BUN are important indicators for assessing renal function. As shown in Fig. 4A and B, the Model group displayed significantly elevated CRE and BUN levels, which were 2.09-fold (67.47 ± 5.15 μmol L⁻¹) and 1.67-fold (11.12 ± 0.92 μmol L⁻¹), respectively, higher than in the Normal group. However, both CGA and various SP doses significantly reduced the CRE and BUN levels (P < 0.05), with SP showing a clear dose-dependent response. This indicates that SP and CGA can alleviate HUA-induced renal damage. The glomeruli are essential components for the excretory functionality of the kidneys. The eGFR can be calculated based on the CRE levels, directly reflecting the filtration and excretory capabilities of the body (Fig. 4C). The eGFR of the HUA rats decreased significantly, which was restored after intervention with various treatments, with the SPH group showing an eGFR level close to that of the Normal group.

Fig. 4 The effect of SP and CGA on the liver and kidney function of the HUA rats. (A) Blood urea nitrogen (BUN). (B) Serum creatinine (CRE). (C) Estimated glomerular filtration rate (eGFR). (D) Alanine aminotransferase (ALT). (E) Aspartate aminotransferase (AST). Data are presented as mean ± SD (n = 8). Different letters between the groups indicate statistically significant differences (P < 0.05).

HUA affects all the organs in the body. Therefore, the ALT and aspartate aminotransferase (AST) levels in the rat serum were measured to assess liver function (Fig. 4D and E). The ALT and AST levels in the Model group rats with HX + PO-induced HUA were significantly higher (P < 0.05) than in the Normal group, indicating severe liver damage. Under the intervention of SP and CGA, ALT and AST exhibited a downward trend numerically. Among them, the SPH group observed a significant difference (p < 0.05), showing 20.26% and 18.14% lower ALT and AST levels, respectively, than in the Model group. No significant differences were evident between the ALT and AST levels of the Sample Control and Normal groups, indicating that SP did not cause liver damage in the rats.

3.5 SP and CGA can regulate the UA metabolic pathway in HUA rats

HX is converted to UA in the liver, with XOR serving as the key enzyme during this process. The XOR expression level in the Model group increased significantly by 77.66% (14.05 ± 1.21 μmol L⁻¹), compared to the Normal group (Fig. 5A). XOR catalyzed xanthine conversion to UA, which elevated the serum UA levels in the Model group rats. The SP intervention groups demonstrated dose-dependent XOR inhibition. The XOR levels in the intervention groups decreased by 13.84% (12.10 ± 1.29 μmol L⁻¹), 21.40% (11.04 ± 0.56 μmol L⁻¹), and 25.93% (10.40 ± 0.98 μmol L⁻¹), respectively, compared to the Model group, representing significant differences. The CGA group also showed lower liver XOR levels, with a decrease of 30.27% (9.80 ± 1.13 μmol L⁻¹) compared to the Model group.

Fig. 5 The effect of SP and CGA on UA metabolism-related targets in the HUA rats. (A) XOR activity in the liver. (B) WB analysis of the URAT1 expression in the kidneys. (C) WB analysis of the ABCG2 expression in the kidneys. (D) WB analysis of the GLUT9 expression in the kidneys. Different letters between the groups indicate statistically significant differences (P < 0.05).

Excretion by the kidneys crucially affected the serum UA levels. Therefore, the UA transporter expression in the rat kidneys was examined (Fig. 5B–D). In HUA conditions, the URAT1 reabsorption transporter was substantially upregulated in the Model group rats, compared to the Normal group (P < 0.05). However, nutritional intervention with SP mitigated the expression of UA reabsorption proteins, reducing UA reabsorption from urine back into the serum. SP intervention enhanced the expression of the ABCG2 secretion transporter, exhibiting significant differences between the levels in the SPM and SPH groups and that of the Model group, which promoted UA secretion from the cells to the lumen. Although the GLUT9 reabsorption transporter was significantly upregulated in HUA conditions, SP intervention substantially downregulated its high expression in the HUA rats, displaying a clear dose-dependent response. Compared to the CGA group, the SPH group with the same phenolic content significantly downregulated GLUT9 expression (P < 0.05), suggesting that SP was more successful in regulating GLUT9, a possible target for its urate-lowering activity. The Sample Control group, which was not subjected to modeling treatment, showed no significant differences from the Normal group regarding the regulation of the three transporters.

3.6 SP and CGA improve renal histopathological changes in HUA rats

The significant reduction in serum UA and improvement in renal functional markers (BUN, CRE, eGFR) following SP intervention were further corroborated by the amelioration of histopathological damage in the kidneys of HUA rats. As shown in Fig. 6, the renal units of the rats in the Normal and Sample Control groups were structurally intact and tightly packed, with neatly arranged renal tubules, complete lumens, and no signs of glomerular hyperplasia or degeneration. Contrarily, the kidneys of the rats in the Model group showed significant morphological damage, with considerable renal tubular epithelial cell atrophy and shedding. The brush border disappeared while the tubular lumens were irregularly shaped with substantial dilation. The glomeruli showed signs of sclerosis, atrophy, and even necrosis while the renal tissue exhibited inflammatory cell infiltration. This indicated that the rats in the Model group displayed acute tubular necrosis after 16 days of modeling with HX + PO to induce HUA, leading to renal inflammation. Compared to the Model group, intervention with SP and CGA reduced renal tubular epithelial cell necrosis, tubular lumen dilation, the degree of glomerular lesions, and inflammatory cell infiltration. The kidney histopathological sections of the SPH and CGA groups were almost identical to those of the Normal group.

Fig. 6 The representative H&E staining images of the rat kidneys (40× and 100×). The black arrows indicate glomerular lesions, the red triangles denote tubular dilation, and the yellow arrows represent inflammatory cells.

3.7 SP and CGA reduce renal inflammatory cytokine levels in HUA Rats via the PI3K/AKT/NF-κB signaling pathway

The observed reduction in renal inflammatory cell infiltration (Fig. 6) prompted us to investigate the underlying molecular mechanisms, particularly focusing on the PI3K/AKT/NF-κB signaling pathway predicted by network pharmacology and implicated in HUA-associated inflammation. Furthermore, we assessed the levels of key pro-inflammatory cytokines downstream of this pathway. Fig. 7A–C show the expression of the representative pro-inflammatory factors (IL-1β, IL-6, and TNF-α) in the rat kidneys. No significant differences were evident between the pro-inflammatory factors of the Sample Control and Normal groups. However, compared to the Normal group, the IL-1β, IL-6, and TNF-α levels in the kidneys of the HUA rats in the Model group increased significantly by 164.16%, 72.47%, and 66.64%, respectively (P < 0.05), indicating that HUA induced a renal inflammatory response. SP and CGA intervention reduced the expression levels of these inflammatory factors. The SPM, SPH, and CGA groups all exhibited good inflammatory factor clearance, with no significant differences from the Normal group.

Fig. 7 The effect of SP and CGA on the renal inflammatory cytokines and related pathway proteins in the HUA rats. (A) IL-1β. (B) IL-6. (C) TNF-α. (D) WB analysis of phospho-PI3K/PI3K. (E) WB analysis of phospho-AKT (Ser473)/AKT1. (F) WB analysis of phospho-NF-κB/NF-κB. Different letters between the groups indicate statistically significant differences (P < 0.05).

Concomitant with the reduction in renal pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), SP and CGA intervention significantly suppressed the phosphorylation of key proteins in the PI3K/AKT/NF-κB signaling pathway (Fig. 7D–F). For NF-κB protein, the phosphorylation ratio in the SPM group was the lowest, but there was no significant difference compared with the SPH group. This suppression is mechanistically linked to the decreased cytokine production, as the transcription factor NF-κB, upon activation, is a master regulator that directly binds to the promoter regions of genes encoding pro-inflammatory cytokines, including IL1B, IL6, and TNF. Thus, the inhibition of the PI3K/AKT/NF-κB cascade by SP effectively dampens the transcriptional activation of these inflammatory mediators in the kidneys of HUA rats.

4. Discussion

This study used an HUA rat model to systematically evaluate the urate-lowering and renal protective effects of SP, a byproduct of sugarcane sugar production. The results showed that SP significantly reduced the SUA levels and demonstrated a dose-dependent urate-lowering effect. Additionally, SP improved liver and kidney function, biochemical indicators, and histological lesions in HUA conditions via multiple pathways. Moreover, the integration of network pharmacological analysis and experimental validation indicated that the SP action mechanism involved key metabolic and inflammatory pathways, including the inhibition of XOR enzyme activity and the regulation of the PI3K/AKT/NF-κB signaling pathway, consequently alleviating renal inflammation and damage in HUA conditions. These findings establish a scientific foundation for the application of SP as a natural urate-lowering and renal protective agent.

Sugarcane, a commercially significant crop used for sugar production, is extensively cultivated worldwide. Sugarcane molasses is a byproduct of sugar production that shows significant potential for other applications. Previous studies have confirmed its strong biological activity. Sara E. Ali et al. used multiple analytical techniques, including NMR, GC/MS, and UPLC/MS, to identify amino acids, organic acids, sugars, phenolic acids, flavonoids, and fatty acids in sugarcane molasses. The results showed that the identified polyphenolic compounds displayed antioxidant properties and the ability to inhibit α-glucosidase and α-amylase.²³ Similarly, the polyphenolic substances identified in sugarcane molasses have shown anti-inflammatory, anti-glycation, and anti-DNA oxidative damage activities.^24–26 However, minimal systematic studies are available on the urate-lowering effect of SP.

4.1 Prediction of therapeutic targets of SP for HUA and establishment of the HUA model

Network pharmacology analysis and prediction showed that the SP extracted from the sugarcane molasses displayed multi-component, multi-target characteristics for HUA. The main identified targets suggest that SP is closely related to UA metabolism and inflammatory responses, indicating their significant involvement in the pathological HUA process. Luo et al. predicted ABCG2 as a key regulatory target during HUA, which was consistent with the enrichment results of this study.²⁷ Subsequent enrichment analysis emphasized the importance of inflammatory processes during SP regulation of HUA and identified the PI3K/AKT signaling pathway as a potential avenue for further research. The PI3K/AKT and NF-κB pathways are connected. AKT can directly phosphorylate the IκB kinase complex, activating the NF-κB pathway, which is crucial in UA-related inflammatory responses.²⁸ Therefore, this study investigated the specific mechanisms of the PI3K-Akt/NF-κB signaling pathway in HUA to verify the related regulatory effect of SP on UA levels and renal inflammation.

Previous research has identified the major polyphenol types and levels in SP, with CGA determined as the most abundant at a concentration of 146.38 μg g⁻¹.¹⁵ Myrna A. Deseo and Bertrand Payet identified CGA as a characteristic component in sugarcane molasses,^5,29 which was used as a reference component to evaluate the urate-lowering activity of SP. The maximum SP dose of 10 g day⁻¹ recommended for human consumption (https://www.nhc.gov.cn/sps/s7892/202205/7777634cb5994c308e12cf3a3255c622.shtml) was converted to an equivalent amount for rats to explore the efficacy of a smaller dose.

XOR converts HX to UA in the liver after ingestion, while PO inhibits uricase to prevent UA deterioration. Therefore, this study combined HX and PO to induce HUA in rats. The SUA levels in the Model group were 4.91-fold higher than in the Normal group, indicating the efficacy of this modeling method. This study showed that SP intervention significantly reduced the SUA levels in HUA rats. Its urate-lowering effect was positively correlated with the dose, suggesting that higher SP consumption reduced the SUA levels. No significant differences were evident between the SUA levels of the SPH and Normal groups, indicating that a high SP dose (1.028 mg SP per g BW per d, equivalent to a human intake of 10 g per 60 kg) effectively decreased the SUA levels. This demonstrated the considerable potential of SP as a natural urate-lowering bioactive substance. Additionally, the Sample Control and Normal groups displayed no substantial SUA content differences, indicating that the residual sugars in SP did not increase these levels. At equivalent phenolic levels, the SUA content in the SPH group was lower than in the CGA group, with a statistically significant difference. This indicated that the urate-lowering activity of SP exceeded that of CGA. CGA contributed to the SP urate-lowering efficacy, which was possibly enhanced further by the polyphenolic component diversity.

4.2 SP reduces UA production and promotes UA excretion

The urine UA levels in the SPL, SPM, SPH, and CGA groups displayed no significant differences from those in the Model group after SP intervention, while the fecal UA content was considerably lower. This disparity may be attributed to the distinct functions of the kidneys and intestines during UA excretion. In healthy individuals, approximately 70% of UA is excreted by the kidneys, representing the main pathway for UA elimination. Nutritional intervention may improve renal function or increase the eGFR of UA, resulting in increased UA excretion via the kidneys. The quantity of UA eliminated by the intestines is minimal. The gut microbiota exhibits certain ability to degrade UA by secreting active enzymes that promote purine and UA deterioration.³⁰ SP may affect the gut microbiota, promoting the UA degradation, resulting in lower fecal UA content in the SP-treated groups compared to the Model group. Studies have shown that mulberry extract regulates the abundance of bacteria related to purine metabolism in the Lactobacillaceae family, consequently reducing UA levels.³¹ Resveratrol increases Lactobacillaceae, Lactobacillus, and Lactobacillus_sp._ESL0791 abundance, which enhances metabolic UA deterioration in the gut and reduces the fecal UA content, consequently decreasing the SUA levels in HUA mice.³²

UA is the final product of purine metabolism, with XOR representing the key rate-limiting enzyme in this metabolic pathway. XOR catalyzes the conversion of HX to xanthine and ultimately to UA. HUA development is often associated with XOR overexpression in the liver. The results of this study indicated that SP intervention significantly inhibited hepatic XOR activity, displaying a good dose–response relationship and reducing UA production in rats, which is one mechanism by which SP lowers UA levels. XOR has three active sites: the iron–sulfur cluster (2Fe/S) cofactor domain, the FAD cofactor domain, and the molybdopterin (MOCO) cofactor domain. The substrate xanthine binds to the molybdenum center, where it undergoes oxidative hydroxylation to form UA, reducing Mo(VI) to Mo(IV), with electrons flowing through the iron–sulfur cluster to the FAD center for reduction. Studies have shown that CGA can effectively and non-competitively inhibit XOR by binding to the XOR-substrate complex, which alters the secondary enzyme structure and reduces UA production.^33,34 Additionally, research has indicated that CGA enhances the stability of the XOR-polyphenol complex, synergistically inhibiting XOR with quercetin, kaempferol, and other compounds.³⁵

HUA is caused by excessive UA production in 20% of cases and by impaired excretion in 80% of cases. The UA excretion level plays a crucial role in HUA. This study demonstrated that SP and CGA reduced the expression of the URAT1 and GLUT9 reabsorption transporters in the kidneys of HUA rats while increasing that of the ABCG2 secretion transporter. Zhang et al. found that oral ferulic acid downregulated the expression of reabsorption transporters and upregulated that of secretion transporters in HUA rats, consequently reducing SUA levels.³⁶ Jiang et al. reached similar conclusions regarding the urate-lowering activity of gallic acid, which were consistent with the observations in the present study.³⁷ This revealed another mechanism by which SP decreased UA levels. SP inhibited the reabsorption of UA during excretion and promoted secretion, increasing UA elimination, which was consistent with the urinary UA results. However, further investigation is needed to clarify the SP regulation of UA transporter expression, and whether it can directly interact with transporters to inhibit UA passage through their channels.³⁸

4.3 SP protects against hepatorenal functional damage under HUA conditions

High UA concentrations can damage various organs in the body. ALT and AST are commonly used to assess liver function, both of which are present in the cytoplasm. Damaged liver cells display significant leakage of these substances, resulting in abnormally elevated levels in the serum. This study found that HUA substantially increased the ALT and AST levels in rats, indicating that this condition caused liver cell damage, the degree of which was mitigated by oral SP and CGA administration. Zhou et al. found that CGA consumption alleviated HUA-induced liver damage in mice.¹⁹ The oxidative stress induced by high UA levels may be a key factor leading to liver damage. In an HUA state, liver cells produce excessive reactive oxygen species (ROS) due to XOR-catalyzed reactions, causing oxidative stress, lipid peroxidation, and endogenous antioxidant defense depletion, consequently mediating tissue damage.³⁹

HUA is often accompanied by the development of kidney disease, while the metabolism of high UA concentrations can cause renal dysfunction. BUN and CRE are commonly used to assess renal function since both are filtered by the glomeruli and excreted by the renal tubules. Higher BUN and CRE levels in the serum indicate more severe renal impairment. The results showed that the UA excretion in the kidneys caused renal damage, while SP and CGA ingestion effectively downregulated the BUN and CRE levels, alleviating the renal dysfunction caused by HUA. H&E staining of the kidney sections of HUA rats showed pathological changes and improvements, confirming the results of the renal function indicators. High UA concentrations can also stimulate the immune cells in the kidneys to produce pro-inflammatory factors, which increase renal inflammation and damage.

4.4 SP exerts anti-inflammatory effects through the activation of the PI3K/AKT/NF-κB signaling pathway

The renal damage caused by inflammation can affect the excretion of uric acid by the kidneys, further elevating serum UA levels and exacerbating the inflammatory response in the kidneys.^9,11 The results showed significantly elevated levels of the typical IL-1β, IL-6, and TNF-α pro-inflammatory factors in the kidneys of the HUA rats, while SP and CGA intervention reduced their content, alleviating renal inflammation. The H&E-stained kidney sections showed pathological changes in the rat kidneys after 16 days of modeling with HX + PO, primarily in three areas: tubular dilation, glomerular atrophy, and inflammatory cell infiltration. These findings were consistent with previous studies regarding the renal pathology observed after HUA modeling.^21,40,41

The eGFR and renal UA transporters were analyzed to determine the mechanism behind HUA-induced renal damage. After filtration by the glomeruli, the UA concentrations exceeded the excretion capacity of the renal tubules and remained in the tubular lumen. The urate precipitation caused by further urine concentration resulted in renal tubular epithelial cell damage and inflammatory cell infiltration. This reduced UA excretion into the urine, creating a vicious cycle that caused glomerular dysfunction, decreased the eGFR, and exacerbated the damage.⁴² SP and CGA intervention enhanced UA transporter expression in the renal tubular epithelial cells, which improved the renal tubule excretion capacity by “unblocking the obstruction”, consequently reducing HUA-induced renal lesions and inflammation, and alleviating renal function decline.

In the preliminary predictions, the significance of the PI3K/AKT signaling pathway in the action of SP on HUA was highlighted, and subsequent experiments confirmed the activation of this pathway under HUA conditions. PI3K/AKT signaling pathway activation is associated with various cellular processes. Wang et al. activated the PI3K/AKT signaling pathway and its downstream NF-κB in HUA conditions, resulting in the release of inflammatory factors and caused pathological kidney damage, which was consistent with the results of the current study.⁴³ NF-κB is a key transcription factor that can induce the expression of various inflammatory factors, such as IL-1β, IL-6, and TNF-α. Its upstream Akt can activate the IKK complex, promoting IκB degradation and NF-κB release into the nucleus, which regulates gene expression and affects cellular inflammatory responses.⁴⁴ Although there was no statistically significant difference between the SPM and SPH groups in the quantification of p-NF-κB expression, as noted in the Results section, the phosphorylation level of NF-κB appeared lowest in the SPM group. This apparent nonlinear trend raises the hypothesis that moderate doses of SP may optimize anti-inflammatory signaling, whereas higher doses could activate compensatory responses that attenuate this effect. Given the multiple feedback loops and crosstalk mechanisms within the NF-κB pathway, medium-dose SP might maintain signaling balance within an optimal regulatory range.⁴⁵ In contrast, higher doses may interfere with normal signaling dynamics or trigger compensatory pathways (such as NIK/IKK1or TRAF6/IRAK1), thereby weakening the inhibitory effect on NF-κB.^46,47

Moreover, PI3K/AKT signaling pathway activation may influence the UA metabolic pathways. Yang et al. found that naringenin inhibited GLUT9 expression by participating in the PI3K/AKT signaling pathway and increased ABCG2 expression by altering that of PDZK1.⁴⁸ In urate nephropathy, the PI3K/AKT signaling pathway activation is associated with renal inflammation and fibrosis. Modulating this signaling pathway may help alleviate renal inflammation and improve UA metabolism, showing a therapeutic effect on HUA.

4.5 Contribution of the characteristic component CGA in SP

CGA is the most abundant polyphenol in SP, significantly exceeding the content of other monophenols. The preliminary network pharmacology analysis showed a high degree of CGA enrichment, indicating a potentially substantial role in the ability of SP to alleviate HUA. This study calibrated the CGA gavage quantity based on the polyphenol content in the SPH group to evaluate the urate-lowering activity of SP. A comprehensive analysis of the experimental results (Fig. 3D) showed that the SUA content was significantly higher in the SPH group than in the CGA group, indicating that the urate-lowering activity of SP exceeded that of the CGA. Furthermore, compared to the CGA, SP was more successful in regulating specific targets such as GLUT9 and AKT. This may be due to the synergistic effect among the polyphenolic components of SP, exhibiting a higher capacity for controlling certain signaling pathways and protein expression. Iwata et al. found that the characteristic polyphenols of sugarcane tip (3CQA, 5CQA, ISO) had limited effects when used alone, but when combined, they significantly enhanced neural differentiation and mitochondrial activity through a synergistic mechanism: CQAs activates the p38 pathway to induce cell cycle arrest, while ISO inhibits the regulation of transcription factors by GSK3β. Together, they up-regulate PGC-1α, driving the maturation and morphological complexity of astrocytes, demonstrating a multi-component and multi-target synergistic effect.⁴⁹ Therefore, future research could explore the structural and functional relationships between the synergistic mechanisms of the SP components.

5. Conclusions

In summary, SP can dose-dependently reduce the SUA levels in HUA rats, with the SPH group (1.028 mg SP per g BW per d) showing the best intervention effect. SP reduces urate via two pathways. It inhibits the activity of XOR, the key enzyme during UA production, consequently reducing excessive UA generation. SP also regulates UA transporter expression in the kidneys (URAT1, ABCG2, and GLUT9), promoting excretion from the blood of rats. The mechanism is illustrated in Fig. 8. SP also decreases inflammatory factor expression via the PI3K/AKT/NF-κB signaling pathway to alleviate HUA-induced renal inflammation and associated tissue damage. Moreover, SP or CGA intervention restore liver and kidney function in HUA rats, with the histopathological sections revealing the same results.

Fig. 8 The therapeutic mechanisms of SP and CGA in HUA rats. Red flat arrows represent inhibitory effects, while green flat arrows denote promotional effects.

CGA plays a crucial role in the ability of SP to reduce urate activity in vivo. However, at the same phenolic level, CGA is less effective than SP in reducing the SUA levels in the HUA rats. This study confirms the urate-lowering and anti-inflammatory activity of sugarcane byproducts in vivo via network pharmacology prediction and experimental validation, highlighting the potential therapeutic value of SP in treating HUA. Future research can focus on oral bioavailability, post-ingestion metabolism or the synergistic effect of polyphenols to enable sugarcane byproduct valorization and guide the development of urate-lowering functional foods.

Author contributions

Kexin Li: conceptualization, investigation, data curation, writing – original draft. Yu Han: investigation, formal analysis, visualization. Yumei Wang: validation, methodology. Chengfeng Zhang: validation, resources, project administration. Wanlu Liu: methodology, validation. Yu Xi: conceptualization, supervision, writing – reviewing & editing. Yanv Zhou: resources, project administration. Lu Li: project administration, supervision. He Li: conceptualization, supervision, writing – reviewing & editing.

Conflicts of interest

There are no conflicts to declare.

Data availability

The data supporting this article have been included as part of the Supplementary Information.

Supplementary information is available. See DOI: https://doi.org/10.1039/d5fo00508f.

Acknowledgements

This work was supported by the Research Foundation for Youth Scholars of Beijing Technology and Business University (RFYS2025) and the National Key Research and Development Program of China (No. 2021YFD2100400).

References

1. K. O. Iwuozor, E. C. Emenike, J. O. Ighalo, S. Eshiemogie, P. E. Omuku and A. G. Adeniyi, Valorization of Sugar Industry's By-products: A Perspective, Sugar Tech, 2022, 24, 1052–1078.
2. F. Santos, P. Eichler, G. Machado, J. De Mattia and G. De Souza, in Sugarcane Biorefinery, Technology and Perspectives, ed. F. Santos, S. C. Rabelo, M. De Matos and P. Eichler, Academic Press, 2020, pp. 21–48,  DOI:10.1016/B978-0-12-814236-3.00002-0.
3. O. El Asri and M. A. Farag, The potential of molasses from different dietary sources in industrial applications: A source of functional compounds and health attributes, a comprehensive review, Food Biosci., 2023, 56, 103263.
4. U. Hewawansa, M. J. Houghton, E. Barber, R. J. S. Costa, B. Kitchen and G. Williamson, Flavonoids and phenolic acids from sugarcane: Distribution in the plant, changes during processing, and potential benefits to industry and health, Compr. Rev. Food Sci. Food Saf., 2024, 23, e13307.
5. M. A. Deseo, A. Elkins, S. Rochfort and B. Kitchen, Antioxidant activity and polyphenol composition of sugarcane molasses extract, Food Chem., 2020, 314, 126180.
6. N. Dalbeth, A. L. Gosling, A. Gaffo and A. Abhishek, Gout, Lancet, 2021, 397, 1843–1855.
7. H. Nishizawa, N. Maeda and I. Shimomura, Impact of hyperuricemia on chronic kidney disease and atherosclerotic cardiovascular disease, Hypertens. Res., 2022, 45, 635–640.
8. R. J. Johnson, L. G. S. Lozada, M. A. Lanaspa, F. Piani and C. Borghi, Uric Acid and Chronic Kidney Disease: Still More to Do, Kidney Int. Rep., 2023, 8, 229–239.
9. V. Andrade-Oliveira, O. Foresto-Neto, I. K. M. Watanabe, R. Zatz and N. O. S. Camara, Inflammation in Renal Diseases: New and Old Players, Front. Pharmacol., 2019, 10, 1192.
10. S. W. Jung, S.-M. Kim, Y. G. Kim, S.-H. Lee and J.-Y. Moon, Uric acid and inflammation in kidney disease, Am. J. Physiol. Renal Physiol., 2020, 318, F1327–F1340.
11. H. Y. Su, C. Yang, D. Liang and H. F. Liu, Research Advances in the Mechanisms of Hyperuricemia-Induced Renal Injury, Biomed Res. Int., 2020, 2020, 5817348.
12. H. L. Pisaniello, S. Lester, D. Gonzalez-Chica, N. Stocks, M. Longo, G. R. Sharplin, E. Dal Grande, T. K. Gill, S. L. Whittle and C. L. Hill, Gout prevalence and predictors of urate-lowering therapy use: results from a population-based study, Arthritis Res. Ther., 2018, 20, 143.
13. M. Chen-Xu, C. Yokose, S. K. Rai, M. H. Pillinger and H. K. Choi, Contemporary Prevalence of Gout and Hyperuricemia in the United States and Decadal Trends: The National Health and Nutrition Examination Survey, 2007-2016, Arthritis Rheumatol., 2019, 71, 991–999.
14. M. Dehlin, L. Jacobsson and E. Roddy, Global epidemiology of gout: prevalence, incidence, treatment patterns and risk factors, Nat. Rev. Rheumatol., 2020, 16, 380–390.
15. J. Wang, M. Wang, C. Zhang, W. Li, T. Zhang, Y. Zhou, M. Flavel, Y. Xi, H. Li and X. Liu, Protective effects of sugarcane polyphenol against UV-B-induced photoaging in Balb/c mouse skin: Antioxidant, anti-inflammatory, and anti-glycosylation Effects, J. Food Sci., 2024, 89, 3048–3063.
16. J. Santana-Gálvez, L. Cisneros-Zevallos and D. A. Jacobo-Velázquez, Chlorogenic Acid: Recent Advances on Its Dual Role as a Food Additive and a Nutraceutical against Metabolic Syndrome, Molecules, 2017, 22, 358.
17. L. Wang, X. Q. Pan, L. S. Jiang, Y. Chu, S. Gao, X. Y. Jiang, Y. H. Zhang, Y. Chen, S. J. Luo and C. Peng, The Biological Activity Mechanism of Chlorogenic Acid and Its Applications in Food Industry: A Review, Front. Nutr., 2022, 9, 943911.
18. X. F. Zhou, B. W. Zhang, X. L. Zhao, Y. X. Lin, Y. Zhuang, J. T. Guo and S. Wang, Chlorogenic Acid Prevents Hyperuricemia Nephropathy via Regulating TMAO-Related Gut Microbes and Inhibiting the PI3K/AKT/mTOR Pathway, J. Agric. Food Chem., 2022, 70, 10182–10193.
19. X. Zhou, B. Zhang, X. Zhao, Y. Lin, J. Wang, X. Wang, N. Hu and S. Wang, Chlorogenic acid supplementation ameliorates hyperuricemia, relieves renal inflammation, and modulates intestinal homeostasis, Food Funct., 2021, 12, 5637–5649.
20. Z. Q. Meng, Z. H. Tang, Y. X. Yan, C. R. Guo, L. Cao, G. Ding, W. Z. Huang, Z. Z. Wang, K. D. Wang, W. Xiao and Z. L. Yang, Study on the anti-gout activity of chlorogenic acid: improvement on hyperuricemia and gouty inflammation, Am. J. Chin. Med., 2014, 42, 1471–1483.
21. W. Hu and D. Xu, Identification of anti-hyperuricemic components from Cichorium intybus L. taproots, Food Biosci., 2023, 56, 103145.
22. L. A. Inker, H. Tighiouart, O. M. Adingwupu, M. G. Shlipak, A. Doria, M. M. Estrella, M. Froissart, V. Gudnason, A. Grubb, R. Kalil, M. Mauer, P. Rossing, J. Seegmiller, J. Coresh and A. S. Levey, CKD-EPI and EKFC GFR Estimating Equations: Performance and Other Considerations for Selecting Equations for Implementation in Adults, J. Am. Soc. Nephrol., 2023, 34, 1953–1964.
23. S. E. Ali, R. A. El Gedaily, A. Mocan, M. A. Farag and H. R. El-Seedi, Profiling Metabolites and Biological Activities of Sugarcane (Saccharum officinarum Linn.) Juice and its Product Molasses via a Multiplex Metabolomics Approach, Molecules, 2019, 24, 934.
24. J. Ji, M. Flavel, X. Yang, O. C. Y. Chen, L. Downey, C. Stough and B. Kitchen, A polyphenol rich sugarcane extract as a modulator for inflammation and neurological disorders, PharmaNutrition, 2020, 12, 100187.
25. P. Yu, X. B. Xu and S. J. Yu, Inhibitory effect of sugarcane molasses extract on the formation of N(epsilon)-(carboxymethyl)lysine and N(epsilon)-(carboxyethyl)lysine, Food Chem., 2017, 221, 1145–1150.
26. Y. Asikin, M. Takahashi, M. Mizu, K. Takara, H. Oku and K. Wada, DNA damage protection against free radicals of two antioxidant neolignan glucosides from sugarcane molasses, J. Sci. Food Agric., 2016, 96, 1209–1215.
27. J. Luo, X. Chen, P. Liang, Z. Zhao, T. Wu, Z. Li, S. Wan, J. Luo, J. Pang, J. Zhang and Y. Tian, Mechanism of anti-hyperuricemia of isobavachin based on network pharmacology and molecular docking, Comput. Biol. Med., 2023, 155, 106637.
28. Y. Zhou, L. Fang, L. Jiang, P. Wen, H. D. Cao, W. C. He, C. S. Dai and J. W. Yang, Uric Acid Induces Renal Inflammation via Activating Tubular NF-κB Signaling Pathway, PLoS One, 2012, 7, e39738.
29. B. Payet, A. S. C. Sing and J. Smadja, Comparison of the concentrations of phenolic constituents in cane sugar manufacturing products with their antioxidant activities, J. Agric. Food Chem., 2006, 54, 7270–7276.
30. E. H. Ezenabor, A. A. Adeyemi and O. S. Adeyemi, Gut Microbiota and Metabolic Syndrome: Relationships and Opportunities for New Therapeutic Strategies, Scientifica, 2024, 2024, 4222083.
31. B. Fang, L. Lu, M. Zhao, X. Luo, F. Jia, F. Feng and J. Wang, Mulberry (Fructus mori) extract alleviates hyperuricemia by regulating urate transporters and modulating the gut microbiota, Food Funct., 2024, 15, 12169–12179.
32. Y. Zhou, Y. Zeng, R. Wang, J. Pang, X. Wang, Z. Pan, Y. Jin, Y. Chen, Y. Yang and W. Ling, Resveratrol Improves Hyperuricemia and Ameliorates Renal Injury by Modulating the Gut Microbiota, Nutrients, 2024, 16, 1086.
33. A. Mehmood, J. Li, A. U. Rehman, R. Kobun, I. U. Llah, I. Khan, F. Althobaiti, S. Albogami, M. Usman, F. Alharthi, M. M. Soliman, S. Yaqoob, K. A. Awan, L. Zhao and L. Zhao, Xanthine oxidase inhibitory study of eight structurally diverse phenolic compounds, Front. Nutr., 2022, 9, 966557.
34. X. Li, W. Jin, W. Zhang and G. Zheng, The inhibitory kinetics and mechanism of quercetin-3-O-rhamnoside and chlorogenic acid derived from Smilax china L. EtOAc fraction on xanthine oxidase, Int. J. Biol. Macromol., 2022, 213, 447–455.
35. J. Li, Y. Ni, J. Li and L. Fan, Unveiling the synergistic inhibition mechanism of polyphenols in Flos Sophorae Immaturus tea on xanthine oxidase by multi-spectroscopy, molecular docking and dynamic simulation methods, J. Mol. Liq., 2024, 398, 124245.
36. N. Zhang, J. Zhou, L. Zhao, Z. Zhao, S. Wang, L. Zhang and F. Zhou, Ferulic acid supplementation alleviates hyperuricemia in high-fructose/fat diet-fed rats via promoting uric acid excretion and mediating the gut microbiota, Food Funct., 2023, 14, 1710–1725.
37. L. Jiang, Y. Wu, C. Qu, Y. Lin, X. Yi, C. Gao, J. Cai, Z. Su and H. Zeng, Hypouricemic effect of gallic acid, a bioactive compound from Sonneratia apetala leaves and branches, on hyperuricemic mice, Food Funct., 2022, 13, 10275–10290.
38. Z. Shen, L. Xu, T. Wu, H. Wang, Q. Wang, X. Ge, F. Kong, G. Huang and X. Pan, Structural basis for urate recognition and apigenin inhibition of human GLUT9, Nat. Commun., 2024, 15, 5039.
39. A. Mehmood, L. Zhao, M. Ishaq, W. Xin, L. Zhao, C. Wang, I. Hossen, H. Zhang, Y. Lian and M. Xu, Anti-hyperuricemic potential of stevia (Stevia rebaudiana Bertoni) residue extract in hyperuricemic mice, Food Funct., 2020, 11, 6387–6406.
40. Y. Li, Z. Zhao, J. Luo, Y. Jiang, L. Li, Y. Chen, L. Zhang, Q. Huang, Y. Cao, P. Zhou, T. Wu and J. Pang, Apigenin ameliorates hyperuricemic nephropathy by inhibiting URAT1 and GLUT9 and relieving renal fibrosis via the Wnt/beta-catenin pathway, Phytomedicine, 2021, 87, 153585.
41. P. Wang, X. Zhang, X. Zheng, J. Gao, M. Shang, J. Xu and H. Liang, Folic Acid Protects against Hyperuricemia in C57BL/6J Mice via Ameliorating Gut-Kidney Axis Dysfunction, J. Agric. Food Chem., 2022, 70, 15787–15803.
42. M. E. Gherghina, I. Peride, M. Tiglis, T. P. Neagu, A. Niculae and I. A. Checherita, Uric Acid and Oxidative Stress—Relationship with Cardiovascular, Metabolic, and Renal Impairment, Int. J. Mol. Sci., 2022, 23, 3188.
43. X. Wang, L. Dong, Y. Dong, Z. Bao and S. Lin, Corn Silk Flavonoids Ameliorate Hyperuricemia via PI3K/AKT/NF-κB Pathway, J. Agric. Food Chem., 2023, 71, 9429–9440.
44. Q. Guo, Y. Jin, X. Chen, X. Ye, X. Shen, M. Lin, C. Zeng, T. Zhou and J. Zhang, NF-κB in biology and targeted therapy: new insights and translational implications, Signal Transduction Targeted Ther., 2024, 9, 53.
45. F. Christian, E. Smith and R. Carmody, The Regulation of NF-κB Subunits by Phosphorylation, Cells, 2016, 5, 12.
46. D. E. Nelson, A. E. C. Ihekwaba, M. Elliott, J. R. Johnson, C. A. Gibney, B. E. Foreman, G. Nelson, V. See, C. A. Horton, D. G. Spiller, S. W. Edwards, H. P. McDowell, J. F. Unitt, E. Sullivan, R. Grimley, N. Benson, D. Broomhead, D. B. Kell and M. R. H. White, Oscillations in NF-κB Signaling Control the Dynamics of Gene Expression, Science, 2004, 306, 704–708.
47. G. van Loo and R. Beyaert, Negative regulation of NF-κB and its involvement in rheumatoid arthritis, Arthritis Res. Ther., 2011, 13, 221.
48. B. Yang, M. Xin, S. Liang, Y. Huang, J. Li, C. Wang, C. Liu, X. Song, J. Sun and W. Sun, Naringenin Ameliorates Hyperuricemia by Regulating Renal Uric Acid Excretion via the PI3K/AKT Signaling Pathway and Renal Inflammation through the NF-κB Signaling Pathway, J. Agric. Food Chem., 2022, 71, 1434–1446.
49. K. Iwata, F. Ferdousi, Y. Arai and H. Isoda, Interactions between Major Bioactive Polyphenols of Sugarcane Top: Effects on Human Neural Stem Cell Differentiation and Astrocytic Maturation, Int. J. Mol. Sci., 2022, 23, 15120.

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