Background: Longan is a fruit tree known to contain many phenolic components, which are capable of protecting people from oxidative damage through an anti-inflammatory mechanism. It may be also worthwhile to study the effect on lowering uric acid activity.
Materials And Methods: This study investigates the lowering of uric acid using longan extracts, including flowers, pericarps, seeds, leaves, and twigs, on potassium-oxonate-induced hyperuricemia mice and its inhibitory actions against xanthine oxidase (XO) activities.
Results: The findings revealed that ethyl acetate fraction of longan extracts exhibited strong XO-inhibitory activity, and the flower extracts (IC50 = 115.8 μg/mL) revealed more potent XO-inhibitory activity to those of pericarps (118.9 μg/mL), twigs (125.3 μg/mL), seeds (262.5 μg/mL), and leaves (331.1 μg/mL) in vitro. In addition, different dosages of longan extract (50-100 mg/kg) were administered to hyperuricemic mice. The lowering effect of longan extracts on uric acid at 75 mg/kg markedly reduced plasma uric acid levels in decreasing order: Flowers (80%) > seeds (72%) > pericarps (64%) > twigs (59%) > leaves (41%), compared with allopurinol (89%). Finally, 10 isolated phytochemicals from longan flowers were then examined in vitro. The results indicated that proanthocyanidin A2 and acetonylgeraniin A significantly inhibited XO activity in vitro. This is the first report providing new insights into the urate-reducing effect of phenolic dimer and hydrolyzable tannin, which can be developed to potential hypouricemic agents.
Summary: Longan flower extracts possess more potent XO-inhibitory activity than pericarps, twigs, seeds, and leaves in vitroThe lowering effect of longan flowers and seeds extracts markedly reduced plasma uric acid levels as compared to allopurinol in vivoThe extract proanthocyanidin A2 and acetonylgeraniin A were demonstrated potent XO inhibitory activity in vitro Abbreviations used: PO: Potassium-oxonate, XO: xanthine oxidase, HE: n-hexane, EA: ethyl acetate, i.p.: intraperitoneal, PBS: phosphate-buffered saline, AP: allopurinol, PUA: plasma uric acid.
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http://dx.doi.org/10.4103/0973-1296.182176 | DOI Listing |
BMC Musculoskelet Disord
January 2025
Department of Internal Medicine, Division of Rheumatology, Soonchunhyang University Seoul Hospital, Soonchunhyang University School of Medicine, Seoul, South Korea.
Background: Obstructive sleep apnea (OSA) is linked to various health conditions, including cardiovascular diseases and metabolic disorders. Hyperuricemia and gout may be associated with OSA, but large-scale studies on this are limited. This study aimed to investigate the association between hyperuricemia/gout and OSA using data from the Korea National Health and Nutrition Survey (KNHANES).
View Article and Find Full Text PDFJ Med Internet Res
December 2024
Department of Medical Informatics, School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing, China.
Background: Primary hypertension (PH) poses significant risks to children and adolescents. Few prediction models for the risk of PH in children and adolescents currently exist, posing a challenge for doctors in making informed clinical decisions.
Objective: This study aimed to investigate the incidence and risk factors of PH in Chinese children and adolescents.
Bioorg Chem
December 2024
Good Clinical Practice Development, Guangdong Provincial Key Laboratory of Bone and Joint Degeneration Diseases, The Third Affiliated Hospital, Southern Medical University, Guangzhou, China. Electronic address:
Inhibition of human concentrative nucleoside transporter 2 (CNT2) could suppress increases in serum urate levels derived from dietary purines. However, the structural basis for substrate recognition of CNT2 is still unknown and only a few inhibitors have been reported. In this study, a homology model of CNT2 was constructed and residues T315, E316, N426, N491, E492, F536 and N538 were identified as binding sites for adenosine through site-directed mutagenesis and a H-adenosine uptake assay.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Saint James School of Medicine, Park Ridge, IL, USA.
Background: Oxidative stress is formed by a perturbation of redox homeostasis and linked to the development of Alzheimer's disease (AD) [1]. This imbalance results in an abundance of free radicals that exceeds the antioxidant capacity. Xanthine oxidase (XO) is an enzyme responsible for producing uric acid through the metabolism of purine nucleotides, specifically hypoxanthine and xanthine to uric acid [2].
View Article and Find Full Text PDFCNS Neurosci Ther
January 2025
Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Aims: To analyze the effect of APOE ε4 on fluid biomarkers and the correlations between blood molecules and CSF biomarkers in AD patients.
Methods: This study enrolled 575 AD patients, 131 patients with non-AD dementia, and 112 cognitively normal (CN) participants, and AD patients were divided into APOE ε4 carriers and non-carriers. Cerebrospinal fluid (CSF) biomarkers and blood-derived biomolecules were compared between AD and CN groups, between non-AD dementia and CN groups, as well as within APOE ε4 subgroups of AD patients.
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