Fatty acid oxidation-induced HIF-1α activation facilitates hepatic urate synthesis through upregulating NT5C2 and XDH

Study on the synergistical effects of characteristic compounds in Osmanthus black tea against xanthine oxidase based on multispectral analysis combined with in silico studies

With the worldwide prevalence of hyperuricemia (HUA), safe and effective natural xanthine oxidase (XOD) inhibitors are in need. This research was aimed to reveal the promising XOD inhibitors in Osmanthus black tea. Here, the combination index (CI) values for TF3 and acteoside were below 0.9, confirming the synergistic inhibitory effects on XOD. Further research confirmed that TF3-acteoside was stronger in inducing static quenching of XOD fluorescence than TF3 or acteoside. Besides, the secondary structure of XOD was significant changed by TF3-acteoside, specifically a decrease in the content of α-Helix and random coil, accompanied by an increase in β-Sheet and β-Turn contents, ultimately its structural stability and rigidity was enhanced. Molecular docking and molecular dynamics simulation analysis verified that TF3-acteoside stably bound to XOD by multiple hydrogen bonds. This study will lay important theoretical basis for the advancement of novel XOD inhibitors and the application of osmanthus black tea in lowering uric acid (UA).

U-Shaped association between apolipoprotein A1 and serum uric acid levels in patients with osteoporotic fractures: a cross-sectional study

Background

Lipid metabolism is closely linked to uric acid metabolism, with previous studies suggesting associations between lipid profiles to serum uric acid (SUA) levels. Apolipoprotein A1 (ApoA1), a key component in lipid metabolism and transport, may also be associated with SUA levels, though research in this area remains limited. This study aimed to investigate the independent association between ApoA1 levels and SUA in patients with osteoporotic fractures (OPF).

Methods

This cross-sectional study included 2,108 OPF patients admitted to Kunshan Hospital, affiliated with Jiangsu University, from January 2017 to August 2023. Serum ApoA1 concentration was considered the exposure variable, and SUA concentration the outcome variable. Adjusted linear regression models and smooth curve fitting were employed to assess the relationship between ApoA1 and SUA. Nonlinear associations were examined using a generalized additive model (GAM), and a segmented regression method identified the inflection point. Univariate and stratified analyses were also performed.

Results

Following adjustment for confounding covariates, a nonlinear relationship, U-shaped association was identified between serum ApoA1 and SUA concentrations, with an inflection point at 1.52 g/L. Estimated effects and 95% confidence intervals to the left and right of the inflection point were -55.20 (-75.57 to -34.82) and 77.33 (22.48 to 132.19), respectively.

Conclusions

A U-shaped relationship between serum ApoA1 and SUA was identified in OPF patients. Based on these findings, we propose the concept of a "SUA trough" within the OPF population, additional research is required to explore the mechanism behind this association.

Association between mixed venous oxygen saturation and serum uric acid levels in patients with heart failure

Hypoxia leads to increased purine metabolism in tissues, resulting in increased serum uric acid levels, and may also cause impaired uric acid excretion in the kidneys and intestinal tract. However, the relationship between hypoxia and serum uric acid levels in patients with heart failure remains largely unexplored. Because mixed venous oxygen saturation is an acute indicator of systemic oxygenation, in this study, we investigated the relationship between mixed venous oxygen saturation and serum uric acid levels. This retrospective analysis included 386 patients with heart failure who underwent cardiac catheterization at our institution. The relationship between mixed venous oxygen saturation and serum uric acid levels was examined by single regression analysis. Stratified regression analysis, structural equation modeling, and partial correlation analysis were used to examine the effects of eight factors known to influence mixed venous oxygen saturation and serum uric acid levels. The single regression analysis showed a significant negative correlation between mixed venous oxygen saturation and serum uric acid levels (P<0.001). Significant negative correlations were also observed in many subgroups in the stratified analysis, in the path diagram based on structural equation modeling, and in the partial correlation analysis. These results suggest that there may be a direct relationship between mixed venous oxygen saturation and serum uric acid levels that is not mediated by any known factor.

Integrating metabolomics with network pharmacology to reveal the mechanism of Poria cocos in hyperuricemia treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperuricemia is a chronic condition characterized by persistently elevated uric acid levels, often leading to gouty arthritis and renal insufficiency. Poria cocos F.A.Wolf, a traditional Chinese medicinal herb, possesses notable diuretic and anti-inflammatory properties and is widely used to treat edema, inflammation, viral infections, and tumors. Recent studies suggest that Poria cocos has the potential to lower uric acid levels and mitigate kidney damage, making it a promising candidate for hyperuricemia treatment. However, its pharmacological mechanisms require further exploration.

AIM OF THE STUDY

This study aims to elucidate the mechanisms by which Poria cocos alleviates hyperuricemia, using metabolomics and network pharmacology approaches.

MATERIALS AND METHODS

Hyperuricemia was induced in rats via a high-yeast diet combined with potassium oxonate. The effects of Poria cocos were assessed by measuring serum uric acid, creatinine, urea nitrogen levels, hepatic xanthine oxidase activity, and renal tissue morphology. Non-targeted metabolomics was employed to identify differential metabolites and explore the metabolic pathways involved in its therapeutic effects. Network pharmacology was utilized to analyze potential targets and signaling pathways, which were validated through molecular docking and ELISA analysis.

RESULTS

Poria cocos extract significantly reduced serum uric acid, creatinine, and urea nitrogen levels, inhibited xanthine oxidase activity, and attenuated kidney damage. Metabolomics combined with network pharmacology identified xanthine dehydrogenase and fatty acid synthase as key targets, while purine metabolism, fatty acid biosynthesis, and primary bile acid biosynthesis were identified as critical pathways. ELISA confirmed that Poria cocos suppressed xanthine dehydrogenase and fatty acid synthase expression in hyperuricemic rats. Molecular docking further verified strong binding interactions between core compounds and key targets.

CONCLUSIONS

Poria cocos alleviates hyperuricemia by modulating multiple compounds, targets, and pathways. Through network pharmacology and metabolomics, it reveals that Poria cocos selectively regulates xanthine dehydrogenase and fatty acid synthase, influencing purine metabolism, fatty acid biosynthesis, and primary bile acid biosynthesis pathways. These findings provide insights into its therapeutic mechanisms, supporting the clinical application of Poria cocos in treating metabolic disorders and kidney damage associated with hyperuricemia.

Association between Body Mass Index and Serum Uric Acid: mediation analysis involving liver enzymes indicators

BACKGROUND

Numerous studies have indicated a growing prevalence of hyperuricemia. Elevated levels of serum uric acid (SUA) have been established as influential factors in conditions such as obesity, metabolic syndrome, diabetes mellitus, gout, and cardiovascular disease. Overweight and obesity are closely related to an increase in SUA. Our objective is to demonstrate the mediating role of liver enzyme in the correlation between body mass index (BMI) and SUA.

METHODS

A total of 5925 adults aged 18 to 65 were included in this cross-sectional study. Logistic regression and mediation analysis were used to investigate the relationship between BMI and hyperuricemia as well as liver enzyme levels. Standard methods were used to determine the biochemical indexes, including SUA, liver enzymes, and blood lipids in the collected samples.

RESULTS

The study revealed that the prevalence of hyperuricemia was 28.0%. Furthermore, the prevalence of overweight and obesity was as high as 48.5%, with 70.7% of this subgroup presenting with hyperuricemia. There was a positive correlation between BMI and hyperuricemia, and elevated levels of liver enzymes (ALT, AST, GGT) were associated with a higher risk of hyperuricemia. The study also observed a positive correlation between BMI and liver enzymes (ALT, AST, GGT). The study findings suggested that ALT, AST, and GGT played significant mediating roles in the relationship between BMI and SUA. Specifically, the unadjusted model revealed that ALT and GGT accounted for 22.12% and 18.13% of the mediation effects, respectively.

CONCLUSIONS

The study found that BMI is associated with hyperuricemia, where liver enzyme abnormalities may have a mediating role. It is suggested that being overweight or obese may affect liver enzyme levels, leading to increased SUA levels. Controlling weight and liver enzyme levels may help prevent and treat hyperuricemia.