Effect of ethanol on metabolism of purine bases (hypoxanthine, xanthine, and uric acid)

Microbial functional pathways based on metatranscriptomic profiling enable effective saliva-based health assessments for precision wellness

It is increasingly recognized that an important step towards improving overall health is to accurately measure biomarkers of health from the molecular activities prevalent in the oral cavity. We present a general methodology for computationally quantifying the activity of microbial functional pathways using metatranscriptomic data. We describe their implementation as a collection of eight oral pathway scores using a large salivary sample dataset (n = 9350), and we evaluate score associations with oropharyngeal disease phenotypes within an unseen independent cohort (n = 14,129). Through this validation, we show that the relevant oral pathway scores are significantly worse in individuals with periodontal disease, acid reflux, and nicotine addiction, compared with controls. Given these associations, we make the case to use these oral pathway scores to provide molecular health insights from simple, non-invasive saliva samples, and as molecular endpoints for actionable interventions to address the associated conditions.

Spermidine attenuates monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting purine metabolism and polyamine synthesis-associated vascular remodeling

Ensuring the homeostatic integrity of pulmonary artery endothelial cells (PAECs) is essential for combatting pulmonary arterial hypertension (PAH), as it equips the cells to withstand microenvironmental challenges. Spermidine (SPD), a potent facilitator of autophagy, has been identified as a significant contributor to PAECs function and survival. Despite SPD's observed benefits, a comprehensive understanding of its protective mechanisms has remained elusive. Through an integrated approach combining metabolomics and molecular biology, this study uncovers the molecular pathways employed by SPD in mitigating PAH induced by monocrotaline (MCT) in a Sprague-Dawley rat model. The study demonstrates that SPD administration (5 mg/kg/day) significantly corrects right ventricular impairment and pathological changes in pulmonary tissues following MCT exposure (60 mg/kg). Metabolomic profiling identified a purine metabolism disorder in MCT-treated rats, which SPD effectively normalized, conferring a protective effect against PAH progression. Subsequent in vitro analysis showed that SPD (0.8 mM) reduces oxidative stress and apoptosis in PAECs challenged with Dehydromonocrotaline (MCTP, 50 μM), likely by downregulating purine nucleoside phosphorylase (PNP) and modulating polyamine biosynthesis through alterations in S-adenosylmethionine decarboxylase (AMD1) expression and the subsequent production of decarboxylated S-adenosylmethionine (dcSAM). These findings advocate SPD's dual inhibitory effect on PNP and AMD1 as a novel strategy to conserve cellular ATP and alleviate oxidative injuries, thus providing a foundation for SPD's potential therapeutic application in PAH treatment.

Impact of alcohol consumption on metabolic dysfunction-associated fatty liver disease development and remission: A longitudinal cohort study

BACKGROUND

The influence of alcohol intake on metabolic dysfunction-associated fatty liver disease (MAFLD) development and remission remains unclear; thus, we aimed to investigate their longitudinal associations.

METHODS

This observational cohort study included 6349 patients who underwent more than two health check-ups over >2 years between April 2013 and March 2021. Generalized estimation equations were used to analyse the longitudinal associations between changes in alcohol intake and MAFLD according to repeated measures at baseline and the most recent stage.

RESULTS

The MAFLD development and remission rates were 20.4 and 5.1 and 9.1 and 4.7% in men and women, respectively. Although alcohol consumption was not a significant factor for MAFLD development, consuming 0.1-69.9 g/week (odds ratio [OR]: 0.672, 95% confidence interval [CI]: 0.469-0.964, p < .05) and ≥280 g/week were significant factors for MAFLD development in males (OR: 1.796, 95% CI: 1.009-3.196, p < .05) and females (OR: 16.74, 95% CI: 3.877-72.24, p < .001). Regardless of quantity and frequency, alcohol consumption was not a significant factor for MAFLD remission. Several noninvasive liver fibrosis scores were significantly associated with alcohol intake quantity and frequency in males with MAFLD development and remission (p < .05). The nonalcoholic fatty liver disease fibrosis score differed significantly between males with and without reduced alcohol intake (p < .05) who showed MAFLD remission.

CONCLUSIONS

Although the influence of alcohol intake on MAFLD development and remission differed, alcohol consumption was not beneficial for MAFLD remission in either sex. Alcohol intake reduction or cessation is recommended to prevent liver fibrosis, even in those who achieve MAFLD remission.

The role of body mass index on the association between the energy-adjusted dietary inflammatory index and hyperuricemia: a mediation analysis based on NHANES (2007-2016)

BACKGROUND

The Energy-Adjusted Dietary Inflammatory Index (E-DII) is related to both body mass index (BMI) and hyperuricemia. However, the association among BMI, hyperuricemia and DII is yet to be fully elucidated. The purpose of this study is to explore the role of BMI in the relationship between E-DII and hyperuricemia in the American population.

METHODS

A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2016, with a sample size of 10,571 participants. The study used a weighted logistic regression model and a generalized additive model (GAM) to explore the associations among BMI, hyperuricemia and E-DII. Furthermore, mediation analysis was utilized to illustrate the mediating relationships among these variables.

RESULTS

The results of the study indicated that a higher E-DII was related to an increased risk of hyperuricemia. The association between E-DII and hyperuricemia was partially mediated by BMI.

CONCLUSIONS

E-DII is associated with hyperuricemia. BMI mediates the relationship between E-DII and hyperuricemia among Americans, which provides crucial information for the prevention of hyperuricemia.

Chronic alcohol and nicotine consumption as catalyst for systemic inflammatory storm and bone destruction in apical periodontitis

AIM

To assess the periapical alveolar bone pattern and the serum levels of proinflammatory cytokines, biochemical markers and metabolites in rats subjected to chronic alcohol and nicotine consumption and induced apical periodontitis.

METHODOLOGY

Twenty-eight male Wistar rats were divided into four groups: Control, Alcohol, Nicotine and Alcohol+Nicotine. The alcohol groups were exposed to self-administration of a 25% alcohol solution, while the other groups were given only filtered water. The nicotine groups received daily intraperitoneal injections of a nicotine solution (0.19 μL of nicotine/mL), whereas the other groups received saline solution. Periapical lesions were induced by exposing the pulps of the left mandibular first molars for 28 days. After euthanasia, the mandibles were removed and the percentage bone volume, bone mineral density, trabecular thickness, trabecular separation and trabecular number of the periapical bone were measured using micro-computed tomography images. Serum samples were collected for analysis of proinflammatory cytokines (IL-1β, IL-4, IL-6 and TNF-α), biochemical and metabolomic analysis. Statistical analysis was performed with a significance level of 5%. Nonparametric data were analysed using the Kruskal-Wallis test followed by Dunn's test, while one-way anova followed by Tukey's test was performed for parametric data.

RESULTS

The groups exposed to alcohol or nicotine consumption exhibited an altered bone pattern indicating lower bone density and higher levels of IL-1β, IL-6 and TNF-α compared to the Control group (p < .05). Significant differences were observed among the groups in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, cholesterol, triglycerides, urea, creatinine, albumin, uric acid, bilirubin and calcium. Metabolomic analysis revealed significant differences in glycine, phosphocholine, lysine, lactate, valine, pyruvate and lipids (CH2 CH2 CO), n(CH2 ) and n(CH3 ). Most of these parameters were even more altered in the simultaneous consumption of both substances compared to single consumption.

CONCLUSION

Alcohol and nicotine chronic consumption altered several metabolic markers, impaired liver and kidney function, increased the production of systemic proinflammatory mediators and harmed the periapical bone microarchitecture in the presence of apical periodontitis. The simultaneous consumption of alcohol and nicotine intensified these detrimental effects.

Seasonal variations for newly prescribed urate-lowering drugs for asymptomatic hyperuricemia and gout in Japan

Background: Urate-lowering drugs (ULDs) have been approved for treatment of asymptomatic hyperuricemia and gout in Japan. Although serum urate levels and rates of gout onset are known to have seasonal variations, no survey results regarding the seasonality of ULD prescriptions for asymptomatic hyperuricemia and gout have been reported. Methods: A large-scale database of medical claims in Japan filed between January 2019 and December 2022 was accessed. In addition to total size of the recorded population for each month examined, the numbers of patients every month with newly prescribed ULDs for asymptomatic hyperuricemia and gout were noted, based on the International Classification of Diseases, 10th Revision, codes E79.0 and M10. Results: The results identified 201,008 patients with newly prescribed ULDs (median age 49.0 years, male 95.6%). Of those, 64.0% were prescribed ULDs for asymptomatic hyperuricemia and 36.0% for gout. The proportion of new ULD prescriptions was seasonal, with that significantly (p < 0.001) higher in summer (June-August) [risk ratio (RR) 1.322, 95% CI 1.218 to 1.436] and autumn (September-November) (RR 1.227, 95% CI 1.129-1.335) than in winter (December-February), whereas the proportion in spring (March-May) was not significantly different from winter. There was no significant difference after stratification by drug type (uric acid production inhibitor/uricosuric agent) or size of the medical institution, nor subgrouping by age or sex (p for interaction = 0.739, 0.727, 0.886, and 0.978, respectively). On the other hand, the proportions of new ULD prescriptions for asymptomatic hyperuricemia were significantly lower and for gout significantly higher in spring than winter, while those were similar in summer and autumn for both groups (p for interaction<0.001). Conclusion: The present findings indicate that new prescriptions for ULDs to treat asymptomatic hyperuricemia or gout in Japan show seasonal differences, with higher rates noted in summer and autumn as compared to winter.

Estimated excretion and clearance of uric acid as optimal surrogate indices for daily urinary uric acid excretion

OBJECTIVES

Daily uric acid excretion (Eua) is an essential index for patients with gout/hyperuricaemia. We identified alternative indices most correlated with 24-hour uric acid clearance (Cua 24 h) and 24-hour Eua (Eua 24 h) using data from the reference interval of urinary clearance and excretion of urate study.

METHODS

The subjects were indoor workers aged 20-65 years who met the Clinical and Laboratory Standards Institute Guidelines C28-A3c. Alternative indices using spot urine were urine uric acid creatinine ratio, Cua-creatinine clearance ratio (Cua/Ccr), Eua-CCr ratio (Eua/Ccr), estimated Cua (eCua), and estimated Eua (eEua). eCua and eEua are the values obtained by multiplying Cua/Ccr and Eua/Ccr with the estimated glomerular filtration rate.

RESULTS

The final number of subjects analysed was 739. Among the indices using spot urine, eCua and eEua showed the highest correlation with Cua 24 h and Eua 24 h, respectively. Compared with Cua 60 min and Eua 60 min obtained from 60-min urine collection, eCua and eEua showed lower root means squared error, lower bias, and significantly higher accuracy of within 30% and within 15%.

CONCLUSIONS

The newly proposed eCua and eEua may be appropriate from a practical perspective.

Luxembourg Parkinson's study -comprehensive baseline analysis of Parkinson's disease and atypical parkinsonism

Background

Deep phenotyping of Parkinson's disease (PD) is essential to investigate this fastest-growing neurodegenerative disorder. Since 2015, over 800 individuals with PD and atypical parkinsonism along with more than 800 control subjects have been recruited in the frame of the observational, monocentric, nation-wide, longitudinal-prospective Luxembourg Parkinson's study.

Objective

To profile the baseline dataset and to explore risk factors, comorbidities and clinical profiles associated with PD, atypical parkinsonism and controls.

Methods

Epidemiological and clinical characteristics of all 1,648 participants divided in disease and control groups were investigated. Then, a cross-sectional group comparison was performed between the three largest groups: PD, progressive supranuclear palsy (PSP) and controls. Subsequently, multiple linear and logistic regression models were fitted adjusting for confounders.

Results

The mean (SD) age at onset (AAO) of PD was 62.3 (11.8) years with 15% early onset (AAO < 50 years), mean disease duration 4.90 (5.16) years, male sex 66.5% and mean MDS-UPDRS III 35.2 (16.3). For PSP, the respective values were: 67.6 (8.2) years, all PSP with AAO > 50 years, 2.80 (2.62) years, 62.7% and 53.3 (19.5). The highest frequency of hyposmia was detected in PD followed by PSP and controls (72.9%; 53.2%; 14.7%), challenging the use of hyposmia as discriminating feature in PD vs. PSP. Alcohol abstinence was significantly higher in PD than controls (17.6 vs. 12.9%, p = 0.003).

Conclusion

Luxembourg Parkinson's study constitutes a valuable resource to strengthen the understanding of complex traits in the aforementioned neurodegenerative disorders. It corroborated several previously observed clinical profiles, and provided insight on frequency of hyposmia in PSP and dietary habits, such as alcohol abstinence in PD.Clinical trial registration: clinicaltrials.gov, NCT05266872.

Study on the acute toxicity of trichlorfon and its breakdown product dichlorvos to goldfish (Carassius auratus) based on 1H NMR metabonomics

Trichlorfon, one of the most widely used organophosphate insecticides, is commonly employed in aquaculture and agriculture to combat parasitic infestations. However, its inherent instability leads to rapid decomposition into dichlorvos (DDVP), increasing its toxicity by eightfold. Therefore, the environmental effects of trichlorfon in real-world scenarios involve the combined effects of trichlorfon and its degradation product, DDVP. In this study, we systematically investigated the degradation of trichlorfon in tap water over time using HPLC and LC-MS/MS analysis. Subsequently, an experiment was conducted to assess the acute toxicity of trichlorfon and DDVP on goldfish (Carassius auratus), employing a 1H NMR-based metabolic approach in conjunction with serum biochemistry, histopathological inspection, and correlation network analysis. Exposure to trichlorfon and its degradation product DDVP leads to increased lipid peroxidation, reduced antioxidant activity, and severe hepatotoxicity and nephrotoxicity in goldfish. Based on the observed pathological changes and metabolite alterations, short-term exposure to trichlorfon significantly affected the liver and kidney functions of goldfish, while exerting minimal influence on the brain, potentially due to the presence of the blood-brain barrier. The changes in the metabolic profile indicated that trichlorfon and DDVP influenced several pathways, including oxidative stress, protein synthesis, energy metabolism, and nucleic acid metabolism. This study demonstrated the applicability and potential of 1H NMR-based metabonomics in pesticide environmental risk assessment, providing a feasible method for the comprehensive study of pesticide toxicity in water environments.

Screening and application of purine degrading Limosilactobacillus fermentum LF-1 from Huangjiu fermentation broth

BACKGROUND

As the important building blocks of nucleic acids, purines are alkaloids and responsible for hyperuricemia and gout. The purine content in Huangjiu is higher, and mainly exists in the form of free bases, which is easier to be absorbed by human body. However, the currently available reports on purine in Huangjiu mainly focus on detection methods and content survey. No studies on the regulation of the purine content in Huangjiu have been reported.

RESULTS

Eighty-four strains, with the degradation capacity of purine, were screened from the fermentation broth of Huangjiu. In detail, the isolated lactic acid bacteria (LAB) strain 75 # showed the strongest degradation ability of guanosine, inosine and four purines, which reduce their levels by 83.4% (guanosine), 97.4% (inosine), 95.1% (adenine), 95.0% (guanine), 94.9% (hypoxanthine) and 65.9% (xanthine), respectively. Subsequently, the LAB strain 75# was identified to be Limosilactobacillus fermentum by 16S rRNA gene sequencing, which was named as Limosilactobacillus fermentum LF-1 and applied to the fermentation of Huangjiu in the laboratory. Compared with the fermentation broth of Huangjiu without adding L. fermentum LF-1, the content of purine compounds in the fermentation broth inoculated with L. fermentum LF-1 was reduced by 64.7%. In addition, the fermented Huangjiu had richer flavor compounds, and the physicochemical indices were in accordance with the national standard of Chinese Huangjiu.

CONCLUSION

The screened strain L. fermentum LF-1 may be a promising probiotic for the development of a novel that can efficiently degrade purine in Huangjiu. © 2023 Society of Chemical Industry.

Metabolomics Assessment of Volume Overload-Induced Heart Failure and Oxidative Stress in the Kidney

The incidence of heart failure (HF) is increasing and is associated with a poor prognosis. Moreover, HF often coexists with renal dysfunction and is associated with a worsened outcome. In many experimental studies on cardiac dysfunction, the function of other organs was either not addressed or did not show any decline. Until now, the exact mechanisms for initiating and sustaining this interaction are still unknown. The objective of this study is to use volume overload to induce cardiac hypertrophy and HF in aortocaval fistula (ACF) rat models, and to elucidate how volume overload affects metabolic changes in the kidney, even with normal renal function, in HF. The results showed the metabolic changes between control and ACF rats, including taurine metabolism; purine metabolism; glycine, serine, and threonine metabolism; glycerophospholipid metabolism; and histidine metabolism. Increasing the downstream purine metabolism from inosine to uric acid in the kidneys of ACF rats induced oxidative stress through xanthine oxidase. This result was consistent with HK-2 cells treated with xanthine and xanthine oxidase. Under oxidative stress, taurine accumulation was observed in ACF rats, indicating increased activity of the hypotaurine-taurine pathway as a defense mechanism against oxidative stress in the kidney. Another antioxidant, ascorbic acid 2-sulfate, showed lower levels in ACF rats, indicating that the kidneys experience elevated oxidative stress due to volume overload and HF. In summary, metabolic profiles are more sensitive than clinical parameters in reacting to damage to the kidney in HF.

Theoretical aspects of the adsorption of normal and modified base pairs of DNA on graphene models toward DNA sequencing

A theoretical understanding of the adsorption of DNA base pairs (GC, AT, CAF-T and CAF-C) on the graphene models (Gr, SiGr and SiGr-COOH) is investigated. Among the complexes, SiGr-COOH_AT is found to have the highest adsorption energies of -202.83 kcal/mol. The strong adsorption between DNA base pairs and the SiGr-COOH model leads to concomitant charge transfer responsible for the stability of the corresponding models and is verified with NBO analysis. AIM analysis discloses the high orbital overlap that signifies the strong interaction. Closed-shell interactions are observed through the positive values of total electron density, and it is also observed that Si-O(N) interaction has both covalent and electrostatic characteristics. This is the first theoretical attempt to investigate the adsorption of DNA base pairs on SiGr-COOH, which is more favourable than other models and may call for further experimental studies, which is crucial in developing new bio-sensors.Communicated by Ramaswamy H. Sarma.

Risk Factors for Hyperuricemia or Gout in Men and Women: The Circulatory Risk in Communities Study (CIRCS)

AIM

We aimed to examine sex-specific risk factors for hyperuricemia or gout in Japanese cohorts.

METHODS

We followed up 3,188 men (mean age, 55.6 years) and 6,346 women (mean age, 54.1 years) without hyperuricemia, gout, or elevated liver enzymes at baseline from 1986 to 1990 for a median of 14.6 years. The participants were considered as having hyperuricemia or gout if their serum uric acid levels were ≥ 7.0 mg/dL or they were receiving treatment for hyperuricemia or gout during annual health checkups. The sex-specific multivariable hazard ratios (HRs) of hyperuricemia or gout incidence were calculated after adjustment for smoking and drinking status, body mass index, hypertension, diabetes, hypercholesterolemia, and hypertriglyceridemia using the Cox proportional-hazard model.

RESULTS

During follow-up, 733 men and 355 women had hyperuricemia or gout. Among men, the multivariable HRs (95% confidence intervals) of hyperuricemia or gout were 1.23 (1.00-1.52) and 1.41 (1.13-1.75) for drinkers of ＜46 and ≥ 46 g ethanol/day, respectively, compared with non-drinkers; 1.00 (0.81-1.24) and 1.18 (0.93-1.50) for smokers of 1-19 and ≥ 20 cigarettes/day, respectively, compared with never smokers; and 1.41 (1.20-1.65) for hypertensive compared with non-hypertensive participants. The HRs for women were 1.02 (0.70-1.48), 1.66 (1.05-2.63), and 1.12 (0.88-1.42) for current drinkers, current smokers, and hypertensive participants, respectively. For both men and women, body mass index, diabetes, hypercholesterolemia, and hypertriglyceridemia were not associated with hyperuricemia or gout incidence.

CONCLUSIONS

Hypertension and alcohol drinking are risk factors for hyperuricemia or gout among men and smoking among women.

Poly(para toluene sulphonic acid) and gold nanoparticles modified glassy carbon electrode for simultaneous voltammetric sensing of xanthine and hypoxanthine

A voltammetric sensor has been developed for the individual as well as simultaneous determination of xanthine (XA) and hypoxanthine (HX) based on an electroactive-polymerised layer of para toluene sulphonic acid and gold nanoparticles composite modified glassy carbon electrode ([p(PTSA)]/AuNPs/GCE)]. Under optimized conditions, an enhancement in the oxidation currents with well-separated and well-resolved peak position and a lower shift in the peak potentials were observed. By square wave voltammetry, the simultaneous determinations of XA and HX were achieved in the linear ranges 6.00 × 10-4 M to 3.00 × 10-6 M and 5.00 × 10-4 M to 1.00 × 10-5 M with detection limits of 4.09 × 10-7 M and 4.10 × 10-7 M, respectively. The mechanistic aspects were unveiled from linear sweep voltammetric studies and found that the electrode processes were diffusion-controlled. Finally, the sensor was successfully employed for the simultaneous determination of spiked amount of XA and HX in synthetic urine and serum samples.

Gut Microbiome-Host Metabolome Homeostasis upon Exposure to PFOS and GenX in Male Mice

Alterations of the normal gut microbiota can cause various human health concerns. Environmental chemicals are one of the drivers of such disturbances. The aim of our study was to examine the effects of exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS)-specifically, perfluorooctane sulfonate (PFOS) and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX)-on the microbiome of the small intestine and colon, as well as on liver metabolism. Male CD-1 mice were exposed to PFOS and GenX in different concentrations and compared to controls. GenX and PFOS were found to have different effects on the bacterial community in both the small intestine and colon based on 16S rRNA profiles. High GenX doses predominantly led to increases in the abundance of Clostridium sensu stricto, Alistipes, and Ruminococcus, while PFOS generally altered Lactobacillus, Limosilactobacillus, Parabacteroides, Staphylococcus, and Ligilactobacillus. These treatments were associated with alterations in several important microbial metabolic pathways in both the small intestine and colon. Untargeted LC-MS/MS metabolomic analysis of the liver, small intestine, and colon yielded a set of compounds significantly altered by PFOS and GenX. In the liver, these metabolites were associated with the important host metabolic pathways implicated in the synthesis of lipids, steroidogenesis, and in the metabolism of amino acids, nitrogen, and bile acids. Collectively, our results suggest that PFOS and GenX exposure can cause major perturbations in the gastrointestinal tract, aggravating microbiome toxicity, hepatotoxicity, and metabolic disorders.

Xanthine oxidase inhibitory potentials of flavonoid aglycones of Tribulus terrestris: in vivo, in silico and in vitro studies

Background

Despite the ongoing safety-driven spate of flavonoid xanthine oxidase (XOD) inhibition investigations, there is a lack of flavonoid-based uricostatic antihyperuricemic agents in clinical medicine. The poor pharmacokinetic profiles of glycosides (the natural form of existence of most flavonoids) relative to their aglycones could be largely responsible for this paradox. This investigation was aimed at providing both functional and molecular bases for the possible discovery of XOD inhibitory (or uricostatic) anti-hyperuricemic flavonoid aglycones from the leaves of a flavonoid-rich medicinal plant, Tribulus terrestris. To this end, the flavonoid aglycone fraction of T. terrestris leaf extract (FATT) was evaluated in vivo for antihyperuricemic activity in ethanol-induced hyperuricemic mice, monitoring serum and liver uric acid levels. Molecular docking and molecular dynamics simulation studies were carried out on the three major flavonoid aglycones of T. terrestris (isorhamnetin, quercetin and kaempferol) against an inhibitor conformation XOD model. The three flavonoids were also subjected to in vitro XOD activity assay, comparing their IC50 to that of allopurinol, a standard uricostatic antihyperuricemic drug.

Results

FATT significantly lowered serum uric acid (p < 0.0001) and liver uric acid (p < 0.05) levels of the experimental animals, implying anti-hyperuricemic activity with uricostatic action mechanism allusions. Molecular docking studies revealed high binding affinity values (− 7.8, − 8.1, − 8.2 kcal/mol) for the aglycones (isorhamnetin, quercetin and kaempferol, respectively). Radius of gyration and RMSD analyses of the molecular dynamics simulation trajectories of the three aglycone–XOD complexes revealed substantial stability, the highest stability being demonstrated by the kaempferol–XOD complex. In vitro XOD activity assay showed kaempferol (IC50: 8.2 ± 0.9 μg/ml), quercetin (IC50: 20.4 ± 1.3 μg/ml) and isorhamnetin (IC50: 22.2 ± 2.1 μg/ml) to be more potent than allopurinol (IC50: 30.1 ± 3.0 μg/ml).

Conclusion

This work provides a scientific basis for the use of T. terrestris in the treatment of hyperuricemia-related (e.g. kidney stone and gout) disorders. It also provides the molecular basis for a focussed screening of the flavonoid aglycones chemical space for the possible discovery of flavonoid-based uricostatic anti-hyperuricemic drugs or drug templates.

Update to the Treatment of Parkinson's Disease Based on the Gut-Brain Axis Mechanism

Gastrointestinal (GI) symptoms represented by constipation were significant non-motor symptoms of Parkinson’s disease (PD) and were considered early manifestations and aggravating factors of the disease. This paper reviewed the research progress of the mechanism of the gut-brain axis (GBA) in PD and discussed the roles of α-synuclein, gut microbiota, immune inflammation, neuroendocrine, mitochondrial autophagy, and environmental toxins in the mechanism of the GBA in PD. Treatment of PD based on the GBA theory has also been discussed, including (1) dietary therapy, such as probiotics, vitamin therapy, Mediterranean diet, and low-calorie diet, (2) exercise therapy, (3) drug therapy, including antibiotics; GI peptides; GI motility agents, and (4) fecal flora transplantation can improve the flora. (5) Vagotomy and appendectomy were associated but not recommended.

Modifiable Factors and Incident Gout Across Ethnicity Within a Large Multiethnic Cohort of Older Adults

OBJECTIVE

Gout disproportionately affects older Pacific Islander and Black populations relative to White populations. However, the ethnic-specific determinants remain understudied within these groups, as well as within other ethnicities. We examined gout incidence and associations with behavioral factors, including diet, alcohol, and smoking, within a large multiethnic population of older adults from the Multiethnic Cohort Study, which linked prospective cohort data to Medicare gout claims between 1999-2016.

METHODS

Using samples of Black (n = 12,370), Native Hawaiian (n = 6459), Japanese (n = 29,830), Latino (n = 17,538), and White (n = 26,067) participants, we conducted multiple Cox regressions, producing hazard ratios (HRs) and 95% CIs.

RESULTS

Relative to White individuals, Native Hawaiians had the highest risk of gout (HR 2.21, 95% CI 2.06-2.38), followed successively by Black and Japanese participants, whereas Latino individuals had a lower risk of gout (HR 0.78, 95% CI 0.73-0.83). Alcohol use was associated with an increased risk, with significantly greater effects observed among Japanese participants drinking ≥ 3 drinks per day (HR 1.46, 95% CI 1.27-1.66), or > 5 beers per week (HR 1.29, 95% CI 1.17-1.43), compared to White individuals (P_interaction < 0.001). Former smokers with ≥ 20 pack-years had an increased risk (HR 1.14, 95% CI 1.06-1.22). Higher dietary quality was associated with a decreased gout risk, with the largest effect observed among White participants (HR_Q5vsQ1 0.84, 95% CI 0.79-0.90), whereas vitamin C was weakly associated with a decreased risk of gout only among Japanese individuals (HR 0.91, 95% CI 0.85-0.98).

CONCLUSION

Overall, notable ethnic differences were observed in both gout risk and associations with modifiable behavioral factors. Our findings offer crucial insights that may improve precision in preventing and managing gout.

Metal Centers and Organic Ligands Determine Electrochemistry of Metal-Organic Frameworks

The properties and applications of metal-organic frameworks (MOFs) can be tuned by their metal centers and organic ligands. To reveal experimentally and theoretically the influence of metal centers and ligands on electrochemical performance of MOFs, three MOFs with copper or zinc centers and organic ligands of 2-methylimidazole (2MI) or 1,3,5-benzenetricarboxylic acid (H₃ BTC) are synthesized and characterized in this study. 2D and porous Cu-2MI exhibits a larger active area, faster electron transfer capability, and stronger adsorption capacity than bulk Cu-BTC and dodecahedron Zn-2MI. Density functional theory calculations of adsorption ability of three MOFs toward xanthine (XA), hypoxanthine (HXA), and malachite green (MG) prove that 2D Cu-2MI has the strongest adsorption energies to three targets. Rotating disk electrode measurements reveal that 2D Cu-2MI features the biggest intrinsic heterogeneous rate constant toward three analytes. On 2D Cu-2MI sensitive and selective monitoring of XA, HXA, and MG is then achieved using differential pulse voltammetry. Their monitoring in real samples on 2D Cu-2MI is accurate and comparable with that using high-performance liquid chromatography. In summary, regulation of electrochemical sensing features of MOFs is realized through defining selected metal centers and organic ligands.

NMR-based metabolomics approach to evaluate the toxicological risks of Tibetan medicine 'Ershiwuwei Shanhu' pill in rats

ETHNOPHARMACOLOGICAL RELEVANCE

'Ershiwuwei Shanhu' Pill (ESP) is a classic Tibetan medicine to treat neurological disorders in nervous system, especially for neurological pains and epilepsy. It contains many Tibet-specific mineral medicines, among which Halloysite (Halloysitum rubrum, HR) was regarded as the main active one. As mineral medicines contain heavy metals with poor solubility, the doubts about its safety restricted its clinical application and further development.

AIM OF THE STUDY

A 7-day acute toxicity of ESP and its main active mineral medicine HR was systematically studied for investigating the safety of ESP and exploring the role of HR in ESP's potential toxicity.

MATERIALS AND METHODS

In this study, the acute oral toxicity assessment of formula-ESP and HR were performed on rats for 7 days at doses equivalent to 10 (1 g/kg) and 40 times (4 g/kg) the typical clinical dose (0.1 g/kg). ¹H NMR based metabolomics profiling, aided with biochemical analysis and histopathology, was conducted to explore the global metabolic changes in the livers and kidneys of the administrated rats.

RESULTS

High-dose HR caused oxidative stress, energy metabolism disorders, purine metabolism impairments and amino acid metabolism imbalance in rats, resulting in hepatotoxicity and nephrotoxicity, which in accordance with the increased biochemical index in blood (ALT, AST, BUN and CRE). ESP (low-dose) induced metabolites changes were far more less than HR in livers, showcasing the distinct advantage of formula in reducing toxicity. Furthermore, low-dose ESP disturbed renal metabolism in a way similar to high-dose HR, which implies that HR might be the major source of the potential nephrotoxicity of ESP.

CONCLUSION

HR exhibited potential hepatoxicity and nephrotoxicity, but the formula- 'Ershiwuwei Shanhu' Pill which contains HR is considered relatively safe.

Child serum metabolome and traffic-related air pollution exposure in pregnancy

BACKGROUND

Maternal exposure to traffic-related air pollution during pregnancy has been shown to increase the risk of adverse birth outcomes and childhood disorders. High-resolution metabolomics (HRM) has previously been employed to identify metabolic responses to traffic-related air pollution in adults, including pregnant women. Thus far, no studies have examined metabolic effects of air pollution exposure in utero on neonates.

METHODS

We retrieved stored neonatal blood spots for 241 children born in California between 1998 and 2007. These children were randomly selected from all California birth rolls to serve as birth-year matched controls for children with retinoblastoma identified from the California cancer registry for a case control study of childhood cancer. We estimated prenatal traffic-related air pollution exposure (particulate matter less than 2.5 μm (PM_2.5)) during the third-trimester using the California Line Source Dispersion Model, version 4 (CALINE4) based on residential addresses recorded at birth. We employed untargeted HRM to obtain metabolic profiles, and metabolites associated with air pollution exposure were identified using partial least squares (PLS) regression and linear regressions. Biological effects were characterized using pathway enrichment analyses adjusting for potential confounders including maternal age, race/ethnicity, and education.

RESULTS

In total we extracted 4038 and 4957 metabolite features from neonatal blood spots in hydrophilic interaction (HILIC) chromatography (positive ion mode) and C18 reverse phase columns (negative ion mode), respectively. After controlling for confounding factors, partial least square regression (Variable Importance in Projection (VIP) ≥ 2) selected 402 HILIC positive and 182 C18 negative features as statistically significantly associated with increasing third trimester PM_2.5 exposure. Using pathway enrichment analysis, we identified metabolites in oxidative stress and inflammation pathways as being altered, primarily involving lipid metabolism.

CONCLUSION

The metabolite features and pathways associated with air pollution exposure in neonates suggest that maternal exposure during late pregnancy contributes to oxidative stress and inflammation in newborn children.

Urinary metabolomic signatures as indicators of injury severity following traumatic brain injury: A pilot study

BACKGROUND

Analysis of fluid metabolites has the potential to provide insight into the neuropathophysiology of injury in patients with traumatic brain injury (TBI).

OBJECTIVE

Using a 1H nuclear magnetic resonance (NMR)-based quantitative metabolic profiling approach, this study determined (1) if urinary metabolites change during recovery in patients with mild to severe TBI; (2) whether changes in urinary metabolites correlate to injury severity; (3) whether biological pathway analysis reflects mechanisms that mediate neural damage/repair throughout TBI recovery.

METHODS

Urine samples were collected within 7 days and at 6-months post-injury in male participants (n = 8) with mild-severe TBI. Samples were analyzed with NMR-based quantitative spectroscopy for metabolomic profiles and analyzed with multivariate statistical and machine learning-based analyses.

RESULTS

Lower levels of homovanillate (R = -0.74, p ≤ 0.001), L-methionine (R = -0.78, p < 0.001), and thymine (R = -0.85, p < 0.001) negatively correlated to injury severity. Pathway analysis revealed purine metabolism to be a primary pathway (p < 0.01) impacted by TBI.

CONCLUSION

This study provides pilot data to support the use of urinary metabolites in clinical practice to better interpret biochemical changes underlying TBI severity and recovery. The discovery of urinary metabolites as biomarkers may assist in objective and rapid identification of TBI severity and prognosis. Thus, 1H NMR metabolomics has the potential to facilitate the adaptation of treatment programs that are personalized to the patient's needs.

The prognostic impact of uric acid in acute heart failure according to coexistence of diabetes mellitus

BACKGROUND AND AIMS

Increased uric acid levels predict higher mortality in heart failure (HF) patients. Patients with diabetes mellitus (DM) appear to have increased xanthine oxidase activity. We aimed to study if the association between uric acid and mortality in acute HF was different according to the coexistence of DM.

METHODS AND RESULTS

We studied a cohort of patients hospitalized due to acute HF in 2009-2010. Patients with no uric acid measurement upon admission were excluded from the analysis.

FOLLOW-UP

2 years; endpoint: all-cause mortality. Patients with elevated uric acid (>80.0 mg/L) were compared with those with lower values. We used a multivariate Cox-regression analysis to assess the prognostic impact of uric acid (both continuous and categorical variable: cut-off 80.0 mg/L). The analysis was stratified according to coexistence of DM. We studied 569 acute HF patients, 44.6%male, mean age 76 years, 290 were diabetic. Median admission uric acid: 81.2 mg/L and 52.2%had uric acid >80.0 mg/L. Elevated uric acid predicted all-cause mortality in acute HF only in patients with DM. The multivariate-adjusted HR of 2-year mortality was 1.68 (95 % CI: 1.15-2.46) for diabetic HF patients with uric acid>80.0 mg/L compared to those with lower levels (p = 0.008) and 1.10 (95 % CI: 1.03-1.18) per each 10 mg/L increase in uric acid (p = 0.007). In non-diabetic HF patients, uric acid was not associated with mortality.

CONCLUSIONS

Increased uric acid predicts ominous outcome in acute HF patients with diabetes, however, it is not prognostic associated in non-diabetics. Uric acid may play a different role in acute HF depending on DM status.

The role of thrifty genes in the origin of alcoholism: A narrative review and hypothesis

In this narrative review, we present the hypothesis that key mutations in two genes, occurring 15 and 10 million years ago (MYA), were individually and then collectively adaptive for ancestral humans during periods of starvation, but are maladaptive in modern civilization (i.e., "thrifty genes"), with the consequence that these genes not only increase our risk today for obesity, but also for alcoholism. Both mutations occurred when ancestral apes were experiencing loss of fruit availability during periods of profound climate change or environmental upheaval. The silencing of uricase (urate oxidase) activity 15 MYA enhanced survival by increasing the ability for fructose present in dwindling fruit to be stored as fat, a consequence of enhanced uric acid production during fructose metabolism that stimulated lipogenesis and blocked fatty acid oxidation. Likewise, a mutation in class IV alcohol dehydrogenase ~10 MYA resulted in a remarkable 40-fold increase in the capacity to oxidize ethanol (EtOH), which allowed our ancestors to ingest fallen, fermenting fruit. In turn, the EtOH ingested could activate aldose reductase that stimulates the conversion of glucose to fructose, while uric acid produced during EtOH metabolism could further enhance fructose production and metabolism. By aiding survival, these mutations would have allowed our ancestors to generate more fat, primarily from fructose, to survive changing habitats due to the Middle Miocene disruption and also during the late-Miocene aridification of East Africa. Unfortunately, the enhanced ability to metabolize and utilize EtOH may now be acting to increase our risk for alcoholism, which may be yet another consequence of once-adaptive thrifty genes.

Risk of gout among Taiwanese adults with ALDH-2 rs671 polymorphism according to BMI and alcohol intake

BACKGROUND

Gout stems from both modifiable and genetic sources. We evaluated the risk of gout among Taiwanese adults with aldehyde dehydrogenase-2 (ALDH2) rs671 single nucleotide polymorphism (SNP) according to body mass index (BMI) and alcohol drinking.

METHODS

We obtained information of 9253 individuals having no personal history of cancer from the Taiwan Biobank (2008-2016) and estimated the association between gout and independent variables (e.g., rs671, BMI, and alcohol drinking) using multiple logistic regression.

RESULTS

Alcohol drinking and abnormal BMI were associated with a higher risk of gout whereas the rs671 GA+AA genotype was associated with a lower risk. The odds ratios (ORs) and 95% confidence intervals (CIs) were 1.297 and 1.098-1.532 for alcohol drinking, 1.550 and 1.368-1.755 for abnormal BMI, and 0.887 and 0.800-0.984 for GA+AA. The interaction between BMI and alcohol on gout was significant for GG (p-value = 0.0102) and GA+AA (p-value = 0.0175). When we stratified genotypes by BMI, alcohol drinking was significantly associated with gout only among individuals with a normal BMI (OR; 95% CI = 1.533; 1.036-2.269 for GG and 2.109; 1.202-3.699 for GA+AA). Concerning the combination of BMI and alcohol drinking among participants stratified by genotypes (reference, GG genotype, normal BMI, and no alcohol drinking), the risk of gout was significantly higher in the following categories: GG, normal BMI, and alcohol drinking (OR, 95% CI = 1.929, 1.385-2.688); GG, abnormal BMI, and no alcohol drinking (OR, 95% CI, = 1.721, 1.442-2.052); GG, abnormal BMI, and alcohol drinking (OR, 95% CI = 1.941, 1.501-2.511); GA+AA, normal BMI, and alcohol drinking (OR, 95% CI = 1.971, 1.167-3.327); GA+AA, abnormal BMI, and no alcohol drinking (OR, 95% CI = 1.498, 1.256-1.586); and GA+AA, abnormal BMI, and alcohol drinking (OR, 95% CI = 1.545, 1.088-2.194).

CONCLUSIONS

Alcohol and abnormal BMI were associated with a higher risk of gout, whereas the rs671 GA+AA genotype was associated with a lower risk. Noteworthy, BMI and alcohol had a significant interaction on gout risk. Stratified analyses revealed that alcohol drinking especially among normal-weight individuals might elevate the risk of gout irrespective of the genotype.

Acute effect of green tea catechins on uric acid metabolism after alcohol ingestion in Japanese men

INTRODUCTION/OBJECTIVES

Alcohol consumption is associated with hyperuricemia and gout. Previous studies have indicated a role for green tea catechins in uric acid (UA) metabolism. This study aimed to elucidate the acute effect of green tea catechins in terms of enhancing urinary excretion of UA and xanthine/hypoxanthine (Xa/HX; UA precursors) after alcohol ingestion.

METHODS

In a randomized crossover study, ten healthy Japanese subjects consumed test meals, including a Japanese distilled spirit (Shōchū) with water (SW) or Shōchū with catechin-rich green tea (SC), each containing 20 g of alcohol. The SC contained 617 mg of catechin in total. Serum and urine UA and Xa/HX concentrations were measured. Blood samples were collected after 2.5 h, and urine samples were collected between 0 and 5 h after consuming the test meal.

RESULTS

Urine UA and Xa/HX excretions were significantly higher in the SC group than in the SW group (UA: SW, 0.45 ± 0.08; SC, 0.52 ± 0.09; Xa/HX: SW, 0.08 ± 0.04; SC, 0.16 ± 0.05 mg/kg/h). UA clearance (C_UA) and fractional UA excretion (FE_UA) tended to increase more in the SC group than in the SW group (C_UA: SW, 7.76 ± 2.14; SC, 8.75 ± 2.23 mL/min/1.73 m²; FE_UA: SW, 6.08 ± 1.36; SC, 6.64 ± 1.42%). No significant differences in serum UA and Xa/HX concentrations were observed between two groups.

CONCLUSIONS

It was concluded that green tea catechins can enhance the excretion of UA and Xa/HX, even though alcohol is ingested.

TRIAL REGISTRATION NUMBER

UMIN000040076. Retrospectively registered 7 April 2020. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045687 Key Points • Green tea catechins enhance the excretion of uric acid and xanthine/hypoxanthine, even when alcohol is ingested simultaneously. • In case of non-adherence of limiting alcohol intake, catechin-rich green tea may be an effective dietary component to continue dietary therapy.

Association of hyperuricemia and gamma glutamyl transferase as a marker of metabolic risk in alcohol use disorder

Excessive alcohol consumption leads to overproduction of urates and renal function plays a critical role in serum uric acid levels. We aimed to assess associations of hyperuricemia in patients with alcohol use disorder (AUD) and comparable Glomerular Filtration Rate (GFR). A total of 686 patients undergoing treatment for AUD between 2013 and 2017 were eligible (77% men); age at admission was 47 years [interquartile range (IQR), 40-53 years], age of onset of alcohol consumption was 16 years [IQR, 16-18 years] and the amount of alcohol consumed was 160 g/day [IQR, 120-240 g/day]. Body Mass Index was 24.7 kg/m² [IQR, 21.9-28.4 kg/m²], eGFR was 105 mL/min/1.73 m² [IQR, 95.7-113.0 mL], 9.7% had metabolic syndrome and 23% had advanced liver fibrosis (FIB-4 > 3.25). Prevalence of hyperuricemia was 12.5%. The eGFR-adjusted multivariate analysis showed that relative to patients with GGT ≤ 50, those with GGT between 51 and 300 U/L and those with GGT > 300 U/L were 4.31 (95% CI 1.62-11.46) and 10.3 (95% CI 3.50-29.90) times more likely to have hyperuricemia, respectively. Our data shows that hyperuricemia in the context of AUD is strongly associated with serum GGT levels and suggest an increased cardio-metabolic risk in this population.

Metabolic Phenotyping Study of Mouse Brains Following Acute or Chronic Exposures to Ethanol

The chronic and acute effect of ethanol administration on the metabolic phenotype of mouse brain was studied in a C57BL/6 mouse model of ethanol abuse using both untargeted and targeted ultra performance liquid chromatography-tandem mass spectrometry. Two experiments based on either chronic (8 week) exposure to ethanol of both male and female mice or acute exposure of male mice for 11 days, plus 2 oral gavage doses of 25% ethanol, were undertaken. Marked differences were found in amino acids, nucleotides, nucleosides, and related metabolites as well as a number of different lipids. Using untargeted metabolite profiling, acute ethanol exposure found significant decreases in several metabolites including nucleosides, fatty acids, glycerophosphocholine, and a number of phospholipids, while chronic exposure resulted in increases in several amino acids with notable decreases in adenosine, acetylcarnitine, and galactosylceramides. Similarly, targeted metabolite analysis, focusing on the hydrophilic fraction of the brain tissue extract, identified significant decreases in the metabolism of amino acids and derivatives, as well as purine degradation especially after chronic exposure to ethanol.

Gut Microbiome and Metabolome Response of Pu-erh Tea on Metabolism Disorder Induced by Chronic Alcohol Consumption

This study investigated the protective effects of pu-erh tea extract (PTE) on alcohol-induced microbiomic and metabolomic disorders. In chronic alcohol-exposed mice, PTE ameliorated chronic alcoholic consumption-induced oxidative stress, inflammation, lipid accumulation, and liver and colon damage through modulating microbiomic and metabolomic responses. PTE restored the alcohol-induced fecal microbiota dysbiosis by elevating the relative abundance of potentially beneficial bacteria, for example, Bifidobacterium and Allobaculum, and decreasing the relative abundance of potentially harmful bacteria, for example, Helicobacter and Bacteroides. The alcohol-induced metabolomic disorder was modulated by PTE, which was characterized by regulations of lipid metabolism (sphingolipid, glycerophospholipid, and linoleic acid metabolism), amino acid metabolism (phenylalanine and tryptophan metabolism), and purine metabolism. Besides, the bacterial metabolites of phytochemicals in PTE might contribute to the protective effects of PTE. Overall, PTE could be a functional beverage to treat chronic alcohol consumption-induced microbiomic and metabolomic disorders.

Uridine Metabolism and Its Role in Glucose, Lipid, and Amino Acid Homeostasis

Pyrimidine nucleoside uridine plays a critical role in maintaining cellular function and energy metabolism. In addition to its role in nucleoside synthesis, uridine and its derivatives contribute to reduction of cytotoxicity and suppression of drug-induced hepatic steatosis. Uridine is mostly present in blood and cerebrospinal fluid, where it contributes to the maintenance of basic cellular functions affected by UPase enzyme activity, feeding habits, and ATP depletion. Uridine metabolism depends on three stages: de novo synthesis, salvage synthesis pathway and catabolism, and homeostasis, which is tightly relating to glucose homeostasis and lipid and amino acid metabolism. This review is devoted to uridine metabolism and its role in glucose, lipid, and amino acid homeostasis.

Anemia and the risk of Parkinson's disease in Korean older adults: A nationwide population-based study

Evidence of the association between anemia and risk of PD (Parkinson’s disease) have been accumulating. This study aimed to examine the relationship between anemia and risk of PD in Korean older adults. Korean adults aged 50 years or older who participated in the Korean National Screening Program (n = 12,342,278) between 2009 and 2013 were followed until 2015. Cox proportional hazards regression models were used to calculate the hazard ratio (HR) of PD, and participants were followed for a mean period of 5.0 years. At the end of follow-up, 3,844 adults were diagnosed with PD. After adjusting for potential confounders, participants with anemia had decreased risk of PD compared to adults without anemia (adjusted HR (aHR) 0.894, 95% CI: 0.809–0.989). Furthermore, aHR of PD was 0.698 (95% CI: 0.546–0.891) in moderate to severe anemia and 0.938 (95% CI: 0.843–1.044) in mild anemia. The protective effect of anemia was also more profound in men (aHR 0.888, 95% CI: 0.774–1.02) than in women (aHR 0.905, 95% CI: 0.782–1.048). In conclusion, anemia was associated with lower risk of PD, particularly for patients with moderate to severe anemia. Our study suggests that further studies may be needed to clarify the relationship between anemia and PD.

What and How Can Physical Activity Prevention Function on Parkinson's Disease?

Aim

This study was aimed at investigating the effects and molecular mechanisms of physical activity intervention on Parkinson's disease (PD) and providing theoretical guidance for the prevention and treatment of PD.

Methods

Four electronic databases up to December 2019 were searched (PubMed, Springer, Elsevier, and Wiley database), 176 articles were selected. Literature data were analyzed by the logic analysis method.

Results

(1) Risk factors of PD include dairy products, pesticides, traumatic brain injury, and obesity. Protective factors include alcohol, tobacco, coffee, black tea, and physical activity. (2) Physical activity can reduce the risk and improve symptoms of PD and the beneficial forms of physical activity, including running, dancing, traditional Chinese martial arts, yoga, and weight training. (3) Different forms of physical activity alleviate the symptoms of PD through different mechanisms, including reducing the accumulation of α-syn protein, inflammation, and oxidative stress, while enhancing BDNF activity, nerve regeneration, and mitochondrial function.

Conclusion

Physical activity has a positive impact on the prevention and treatment of PD. Illustrating the molecular mechanism of physical activity-induced protective effect on PD is an urgent need for improving the efficacy of PD therapy regimens in the future.

Relationship between coffee consumption and serum uric acid level in the general Korean population: A nationwide cross-sectional study

OBJECTIVE

Coffee is one of the world's most consumed beverages, and its consumption is increasing. Serum uric acid levels are affected by dietary factors, and increased levels can cause a variety of diseases, including gout. This study aimed to investigate the relationship between coffee consumption and serum uric acid levels in the general Korean population.

METHODS

A nationwide cross-sectional study was conducted using data from the Korean National Health and Nutrition Examination Survey in 2016. A total of 3005 participants who checked serum uric acid levels and a completed coffee consumption survey were included (1146 men and 1859 women). The amount of coffee consumption was examined via self-reporting and categorized as none, <1 cup, 1-2 cups, 2-5 cups, and ≥5 cups of coffee consumed daily.

RESULTS

The mean serum uric acid level of the men was 5.91 ± 1.24 mg/dL and that of women was 4.29 ± 0.97 mg/dL. In the multiple linear regression analysis, there were no significant differences in the serum uric acid levels between the non-coffee-drinking group and the coffee-drinking group (<1 cup, 1-2 cups, 2-5 cups, and ≥5 cups of coffee) in both men and women (P = .569, .258, .466, and .751, respectively, in men; .185, .520, .116, and .302, respectively, in women).

CONCLUSIONS

There was no significant relationship between coffee consumption and serum uric acid levels in the general Korean population.

Study of Fecal and Urinary Metabolite Perturbations Induced by Chronic Ethanol Treatment in Mice by UHPLC-MS/MS Targeted Profiling

Alcoholic liver disease (ALD) as a consequence of ethanol chronic consumption could lead to hepatic cirrhosis that is linked to high morbidity and mortality. Disease diagnosis is still very challenging and usually clear findings are obtained in the later stage of ALD. The profound effect of ethanol on metabolism can be depicted using metabolomics; thus, the discovery of novel biomarkers could shed light on the initiation and the progression of the ALD, serving diagnostic purposes. In the present study, Hydrophilic Interaction Liquid Chromatography tandem Mass Spectrometry HILIC-MS/MS based metabolomics analyisis of urine and fecal samples of C57BL/6 mice of both sexes at two sampling time points was performed, monitoring the effect of eight-week ethanol consumption. The altered hepatic metabolism caused by ethanol consumption induces extensive biochemical perturbations and changes in gut microbiota population on a great scale. Fecal samples were proven to be a suitable specimen for studying ALD since it was more vulnerable to the metabolic changes in comparison to urine samples. The metabolome of male mice was affected on a greater scale than the female metabolome due to ethanol exposure. Precursor small molecules of essential pathways of energy production responded to ethanol exposure. A meaningful correlation between the two studied specimens demonstrated the impact of ethanol in endogenous and symbiome metabolism.

Gouty Tophi Manifesting as a Pancreatic Foci

Gout is a common disorder of uric acid metabolism highly prevalent in our population. The majority of patients with gout present with acute monoarticular arthritis, but a significant proportion of patients also go on to develop chronic tophaceous gout. Musculoskeletal sites are the usual sites of tophus formation and, very rarely, tophi may form in a visceral organ. We present a case of pancreatic gout of which only 3 cases have been reported. Our case is unique and challenging, as it initially masqueraded as a pancreatic neoplasm creating many diagnostic dilemmas.

Different-shaped curves for serum uric acid with and without diabetes: Results from China Health and Retirement Longitudinal Study

BACKGROUND

Several studies have revealed conflicting results regarding the relationship between serum uric acid (SUA) and blood glucose concentrations. The aim of this study was to identify the shape of the curve between SUA and either fasting plasma glucose (FPG) or HbA1c in diabetic and non-diabetic participants.

METHODS

This cross-sectional study of the relationship between SUA and diabetes and non-diabetes was conducted in 10 266 participants. Data from the national baseline survey of the China Health and Retirement Longitudinal Study (CHARLS; 2011-12) were used. Restrictive cubic spline regression and two piecewise linear regression models were used to detect non-linear trends and calculate the slope of each segment.

RESULTS

After adjusting for all confounding factors in all subjects, an L-shaped relationship was found between FPG and SUA in males (β₂  = 3.47, P < 0.01) and females (β₂  = 5.84, P < 0.01), as well as between HbA1c and SUA in males (β₂  = 0.10, P = 0.03) and females (β₂  = 0.12, P = 0.02). In non-diabetic individuals, there was a positive linear correlation between FPG and SUA in females (β = 0.62, P = 0.02). After a diagnosis of diabetes, a negative linear relationship was found between SUA and blood glucose in males, and a nearly L-shaped curve was found in females.

CONCLUSIONS

An L-shaped association was found between SUA and blood glucose in both genders. Stratified analysis revealed an L-shaped curve only in diabetic females. Further studies are warranted to investigate the mechanisms of the association between uric acid and blood glucose levels.

Xanthine oxidase activity in type 2 diabetic Nigerians

AIM

This study evaluated the activity of xanthine oxidase in Nigerians with type 2 diabetic mellitus as well as its relationship with lipid peroxidation, inflammatory bio markers and glycemic control indices.

METHODS

Two hundred and thirty seven (237) subjects, comprising of one hundred and fifty seven (157) DM subjects and eighty (80) aged matched controls participated in this study. Blood samples were collected from the participants for the estimations of xanthine oxidase activity, uric acid, malon diadehyde (MDA), erythrocyte sedimentation rate (ESR), high sensitive c - reactive protein (hs CRP), glucose, fructosamine and glycosylated hemoglobin by standard methods.

RESULTS

The results of this study showed a significantly increased activity of xanthine oxidase in DM (0.044 ± 0.05μ/mg) compared with apparently healthy controls (0.028 ± 0.00 μ/mg). The mean plasma levels of MDA (42.40 ± 2.50μmol/l) and uric acid (7.22 ± 0.20 mg/dl) in DM were significantly higher (p ≤ 0.05) than healthy non DM group. The mean levels of hs CRP in DM (4.09 ± 0.91μg/ml) was significantly higher than controls (1.30 ± 0.50μg/ml, p = 0.009). While no association of xanthine oxidase was observed with glycemic control indices and hs CRP, a negative association of xanthine oxidase was observed with MDA (r = -0.514, p = 0.000).

CONCLUSION

Increased activity of xanthine oxidase in DM was associated with increased lipid peroxidation and could be a salient entity towards the onset on complications.

Metabolomic analysis of male combat veterans with post traumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with impaired major domains of psychology and behavior. Individuals with PTSD also have increased co-morbidity with several serious medical conditions, including autoimmune diseases, cardiovascular disease, and diabetes, raising the possibility that systemic pathology associated with PTSD might be identified by metabolomic analysis of blood. We sought to identify metabolites that are altered in male combat veterans with PTSD. In this case-control study, we compared metabolomic profiles from age-matched male combat trauma-exposed veterans from the Iraq and Afghanistan conflicts with PTSD (n = 52) and without PTSD (n = 51) (‘Discovery group’). An additional group of 31 PTSD-positive and 31 PTSD-negative male combat-exposed veterans was used for validation of these findings (‘Test group’). Plasma metabolite profiles were measured in all subjects using ultrahigh performance liquid chromatography/tandem mass spectrometry and gas chromatography/mass spectrometry. We identified key differences between PTSD subjects and controls in pathways related to glycolysis and fatty acid uptake and metabolism in the initial ‘Discovery group’, consistent with mitochondrial alterations or dysfunction, which were also confirmed in the ‘Test group’. Other pathways related to urea cycle and amino acid metabolism were different between PTSD subjects and controls in the ‘Discovery’ but not in the smaller ‘Test’ group. These metabolic differences were not explained by comorbid major depression, body mass index, blood glucose, hemoglobin A1c, smoking, or use of analgesics, antidepressants, statins, or anti-inflammatories. These data show replicable, wide-ranging changes in the metabolic profile of combat-exposed males with PTSD, with a suggestion of mitochondrial alterations or dysfunction, that may contribute to the behavioral and somatic phenotypes associated with this disease.

Rhubarb Protect Against Tubulointerstitial Fibrosis by Inhibiting TGF-β/Smad Pathway and Improving Abnormal Metabolome in Chronic Kidney Disease

Tubulointerstitial fibrosis is the final common pathway for all kidney diseases leading to chronic kidney disease (CKD). TGF-β/Smad signaling pathway plays a key role in renal fibrosis. Previous studies have revealed that rhubarb extracts attenuated the increase of transforming growth factor-β 1 (TGF-β1) in CKD rats. To gain an in-depth insight into the mechanism of the anti-fibrotic activities of the rhubarb extracts, we investigated the influence of rhubarb extracts on TGF-β/Smad signaling pathway and the influence on metabolome in a rat model of CKD with adenine-induced chronic tubulointerstitial nephropathy. Male Sprague-Dawley rats were divided into four groups, including control, CKD, CKD + petroleum ether extract, CKD + ethyl acetate extract, and CKD + n-butanol extract groups. Kidneys harvested on the week three were evaluated for renal fibrosis, the expression of proteins in TGF-β/Smad signaling pathway and metabolomic study. We found rhubarb extracts suppressed TGF-β/Smad3-mediated renal fibrosis by reducing the TGF-β1, transforming growth factor-β receptor I (TGF-β RI), transforming growth factor-β receptor II (TGF-β RII), Smad2, p-Smad2, Smad3, p-Smad3, and Smad4, meanwhile increased Smad7. In addition, rhubarb extracts mitigated renal injury and dysfunction, and either fully or partially reversed the abnormalities of tissue metabolites. Thus, rebalancing the disorder of TGF-β/Smad signaling and metabolic dysfunction by treatment with rhubarb extracts may represent as an effective therapy for CKD associated with fibrosis.

Activity of xanthine oxidase in plasma correlates with indices of insulin resistance and liver dysfunction in patients with type 2 diabetes mellitus and metabolic syndrome: A pilot exploratory study

Aims/Introduction

There is controversy as to whether hyperuricemia is an independent risk factor for cardiometabolic diseases. The serum level of uric acid is affected by a wide variety of factors involved in its production and excretion. In contrast, evidence has accumulated that locally‐ and systemically‐activated xanthine oxidase (XO), a rate‐limiting enzyme for production of uric acid, is linked to metabolic derangement in humans and rodents. We therefore explored the clinical implication of plasma XO activity in patients with type 2 diabetes mellitus and metabolic syndrome (MetS).

Materials and Methods

We enrolled 60 patients with type 2 diabetes mellitus and MetS. MetS was defined according to the 2005 International Diabetes Federation guidelines. Plasma XO activity was measured by highly‐sensitive fluorometric assay measuring the conversion of pterin to isoxanthopterin, and explored associations between the value of plasma XO activity and metabolic parameters.

Results

The value of plasma XO activity was correlated with indices of insulin resistance and the level of circulating liver transaminases. In contrast, the level of serum uric acid was not correlated with indices of insulin resistance. The value of plasma XO activity was not correlated with the serum uric acid level.

Conclusions

Plasma XO activity correlates with indices of insulin resistance and liver dysfunction in Japanese patients with type 2 diabetes mellitus and MetS. Through assessing the plasma XO activity, patients showing normal levels of serum uric acid with higher activity of XO can be screened, thereby possibly providing a clue to uncovering metabolic risks in type 2 diabetes mellitus and MetS patients.

Habitual exercise decreases plasma xanthine oxidoreductase activity in middle-aged and older women

The aim of present study was to investigate the association between plasma xanthine oxidoreductase activity, which has gained attention as a novel preventive target of cardiovascular disease, and various physiological parameters and was to determine the effects of habitual exercise on plasma xanthine oxidoreductase activity in middle-aged and older women. In the cross-sectional study, we investigated the association between plasma xanthine oxidoreductase activity and various physiological parameters in 94 middle-aged and older women. In the interventional study, subjects (n = 22) were divided into two groups: exercise (n = 12) or the control group (n = 10), whereby we examined the effect of 12-week aerobic exercise training on plasma xanthine oxidoreductase activity in middle-aged and older women. The cross-sectional study demonstrated that plasma xanthine oxidoreductase activity was significantly associated with various physiological parameters, including visceral fat and daily step counts. In the interventional study, the plasma xanthine oxidoreductase activity significantly decreased after the 12-week aerobic exercise training, its changes were inversely associated with the changes in daily step counts. Our results revealed that the plasma xanthine oxidoreductase activity was associated with visceral fat accumulation and lack of exercise, and it was decreased by the aerobic exercise training.

The 1H-NMR-based metabolite profile of acute alcohol consumption: A metabolomics intervention study

Metabolomics studies of disease conditions related to chronic alcohol consumption provide compelling evidence of several perturbed metabolic pathways underlying the pathophysiology of alcoholism. The objective of the present study was to utilize proton nuclear magnetic resonance (1H-NMR) spectroscopy metabolomics to study the holistic metabolic consequences of acute alcohol consumption in humans. The experimental design was a cross-over intervention study which included a number of substances to be consumed-alcohol, a nicotinamide adenine dinucleotide (NAD) supplement, and a benzoic acid-containing flavoured water vehicle. The experimental subjects-24 healthy, moderate-drinking young men-each provided six hourly-collected urine samples for analysis. Complete data sets were obtained from 20 of the subjects and used for data generation, analysis and interpretation. The results from the NMR approach produced complex spectral data, which could be resolved sufficiently through the application of a combination of univariate and multivariate methods of statistical analysis. The metabolite profiles resulting from acute alcohol consumption indicated that alcohol-induced NAD+ depletion, and the production of an excessive amount of reducing equivalents, greatly perturbed the hepatocyte redox homeostasis, resulting in essentially three major metabolic disturbances-up-regulated lactic acid metabolism, down-regulated purine catabolism and osmoregulation. Of these, the urinary excretion of the osmolyte sorbitol proved to be novel, and suggests hepatocyte swelling due to ethanol influx following acute alcohol consumption. Time-dependent metabolomics investigations, using designed interventions, provide a way of interpreting the variation induced by the different factors of a designed experiment, thereby also giving methodological significance to this study. The outcomes of this approach have the potential to significantly advance our understanding of the serious impact of the pathophysiological perturbations which arise from the consumption of a single, large dose of alcohol-a simulation of a widespread, and mostly naive, social practice.

Hyper-Uricemia and Gouty Access in the Adult Population of the Southeast of Gabon: Biochemical Aspects

Gout is caused by a chronic hyperuricemia whose complications are not currently well evaluated in Africa. The aim of this study was to determine the prevalence and risk factors of hyperuricemia and gout in 85 patients recruited. A total of 26 cases of hyperuricemia, i.e., 30.6% of the study population, with 12 cases of gout and seven cases of gouty access. In this population, hyperuricemia was proportional to age (p-value < 10^-4, OR = 2.6), but it was more prevalent in men, 23.5% versus 7.1% for women (p-value = 0.0047). In addition, none of these women showed signs of a gouty affection. Consumption of alcohol (OR = 13) and nucleoprotein-rich foods, obesity (BMI 30 kg/m²; OR = 6), family history of gout (OR = 6.8), as well as diseases such as high blood pressure (associated with taking diuretics; OR = 1.7), renal insufficiency (OR = 4.4) and diabetes (p < 0.049) were the main factors of the diseases associated with gout and hyperuricemia in this population. The biochemical role of these factors may increase and/or decrease the processes of synthesis and/or elimination of uric acid by acting on metabolites involved in the regulation of urate production.

The polymorphism rs671 at ALDH2 associated with serum uric acid levels in Chinese Han males: A genome-wide association study

Serum uric acid (SUA) levels are highly heritable and an increased SUA level is one of important risk factors for gout, diabetes, metabolic syndrome, and cardiovascular diseases. The genetic variants underlying SUA remains largely unexplored. The aim was to explore new genetic variants underlying SUA in Chinese Han. We performed a genome-wide association study of SUA levels in Han Chinese. The discovery set contained 1634 samples and subsequent replication was comprised of 1649 females and 1169 males. 2620 subjects were recruited in the detailed analysis of rs671, alcohol drinking and SUA. We found a genome-wide significant association between SUA level and the SNP rs671 at ALDH2 (P = 1.2 × 10^-10) in the merged data. In addition, we also replicated the signal from rs3733590 at SLC2A9 (P = 1.0 × 10^-10). In males, about 0.21% to 1.95% of the total variance for SUA can be explained by rs671 using linear regression models in four independent cohorts. Of those, 56.75% to 93.51% might be explained by altering alcohol consumption due to rs671. No statistical association of rs671 and SUA was observed in females (P = 0.409). Furthermore, we observed a causal relationship between alcohol consumption and SUA in males using rs671 as an instrumental variable (P = 5.1 × 10^-4). We replicated the previous findings in SLC2A9. Our evidence supported that rs671 was associated with SUA by affecting alcohol consumption in males. This finding strongly suggests a role for alcohol consumption in the development of hyperuricaemia and uric acid related traits.