DKB114, A Mixture of Chrysanthemum Indicum Linne Flower and Cinnamomum Cassia (L.) J. Presl Bark Extracts, Improves Hyperuricemia through Inhibition of Xanthine Oxidase Activity and Increasing Urine Excretion

Inhibitory interaction of flavonoids with organic cation transporter 2 and their structure-activity relationships for predicting nephroprotective effects

Organic cation transporter 2 (OCT2) is mainly responsible for the renal secretion of various cationic drugs, closely associated with drug-induced acute kidney injury (AKI). Screening and identifying potent OCT2 inhibitors with little toxicity in natural products in reducing OCT2-mediated AKI is of great value. Flavonoids are enriched in various vegetables, fruits, and herbal products, and some were reported to produce transporter-mediated drug-drug interactions. This study aimed to screen potential inhibitors of OCT2 from 96 flavonoids, assess the nephroprotective effects on cisplatin-induced kidney injury, and clarify the structure-activity relationships of flavonoids with OCT2. Ten flavonoids exhibited significant inhibition (>50%) on OCT2 in OCT2-HEK293 cells. Among them, the six most potent flavonoid inhibitors, including pectolinarigenin, biochanin A, luteolin, chrysin, 6-hydroxyflavone, and 6-methylflavone markedly decreased cisplatin-induced cytotoxicity. Moreover, in cisplatin-induced renal injury models, they also reduced serum blood urea nitrogen (BUN) and creatinine levels to different degrees, the best of which was 6-methylflavone. The pharmacophore model clarified that the aromatic ring, hydrogen bond acceptors, and hydrogen bond donors might play a vital role in the inhibitory effect of flavonoids on OCT2. Thus, our findings would pave the way to predicting the potential risks of flavonoid-containing food/herb-drug interactions in humans and optimizing flavonoid structure to alleviate OCT2-related AKI.

Research progress on the prevention and treatment of hyperuricemia by medicinal and edible plants and its bioactive components

Hyperuricemia is another common metabolic disease, which is considered to be closely related to the development of many chronic diseases, in addition to the "three highs." Currently, although drugs show positive therapeutic effects, they have been shown to produce side effects that can damage the body. There is growing evidence that medicinal and edible plants and their bioactive components have a significant effect on hyperuricemia. In this paper, we review common medicinal and edible plants with uric acid-lowering effects and summarize the uric acid-lowering mechanisms of different bioactive components. Specifically, the bioactive components are divided into five categories: flavonoids, phenolic acids, alkaloids, polysaccharides, and saponins. These active substances exhibit positive uric acid-lowering effects by inhibiting uric acid production, promoting uric acid excretion, and improving inflammation. Overall, this review examines the potential role of medicinal and edible plants and their bioactive components as a means of combating hyperuricemia, with the hope of providing some reference value for the treatment of hyperuricemia.

Corn Silk Flavonoids Ameliorate Hyperuricemia via PI3K/AKT/NF-κB Pathway

Hyperuricemia (HUA) is a widespread metabolic disease marked by an elevated level of uric acid, and is a risk factor for premature death. The protective effect of corn silk flavonoids (CSF) against HUA and its potential mechanisms were explored. Five important apoptosis and inflammation-related signaling pathways were identified by network pharmacological analysis. The CSF exhibited significant uric acid (UA)-lowering activity in vitro by decreasing xanthine oxidase (XOD) and increasing hypoxanthine-guanine phosphoribosyl transferase levels. In a potassium oxonate-induced HUA in vivo, CSF treatment effectively inhibited XOD activity and promoted UA excretion. Furthermore, it decreased the levels of TNF-α and IL-6 and restored pathological damage. In summary, CSF is a functional food component to improve HUA by reducing inflammation and apoptosis through the down-regulating PI3K/AKT/NF-κB pathway.

Purine-Induced IFN-γ Promotes Uric Acid Production by Upregulating Xanthine Oxidoreductase Expression

OBJECTIVE

Limiting purine intake, inhibiting xanthine oxidoreductase (XOR) and inhibiting urate reabsorption in proximal tubule by uricosuric drugs, to reduce serum uric acid (UA) levels, are recognized treatments for gout. However, the mechanism of increased how XOR expression and activity in hyperuricemia and gout remains unclear. This study aims to explore whether exogenous purines are responsible for increased XOR expression and activity.

METHODS

HepG2 and Bel-7402 human hepatoma cells were stimulated with exogenous purine, or were exposed to conditioned growth medium of purine-stimulated Jurkat cells, followed by measurement of XOR expression and UA production to determine the effect of lymphocyte-secreted cytokines on XOR expression in hepatocytes. The expression of STAT1, IRF1 and CBP and their binding on the XDH promoter were detected by western blotting and ChIP-qPCR. The level of DNA methylation was determined by bisulfite sequencing PCR. Blood samples from 117 hyperuricemia patients and 119 healthy individuals were collected to analyze the correlation between purine, UA and IFN-γ concentrations.

RESULTS

Excess of purine was metabolized to UA in hepatocyte metabolism by XOR that was induced by IFN-γ secreted in the conditioned growth medium of Jurkat cells in response to exogenous purine, but it did not directly induce XOR expression. IFN-γ upregulated XOR expression due to the enhanced binding of STAT1 to IRF1 to further recruit CBP to the XDH promoter. Clinical data showed positive correlation of serum IFN-γ with both purine and UA, and associated risk of hyperuricemia.

CONCLUSION

Purine not only acts as a metabolic substrate of XOR for UA production, but it induces inflammation through IFN-γ secretion that stimulates UA production through elevation of XOR expression.

Saengmaeksan, a traditional herbal formulation consisting of Panax ginseng, ameliorates hyperuricemia by inhibiting xanthine oxidase activity and enhancing urate excretion in rats

Background

Saengmaeksan (SMS) is a traditional Korean medicine composed of three herbs, Panax ginseng, Schisandra chinensis, and Liriope platyphylla. SMS is used to treat respiratory and cardiovascular disorders. However, whether SMS exerts antihyperuricemic effects is unknown.

Methods

Effects of the SMS extract in water (SMS-W) and 30% ethanol (SMS-E) were studied in a rat model of potassium oxonate-induced hyperuricemia. Uric acid concentrations and xanthine oxidase (XO) activities were evaluated in the serum, urine, and hepatic tissue. Using renal histopathology to assess kidney function and uric acid excretion, we investigated serum creatinine and blood urea nitrogen concentrations, as well as protein levels of renal urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), and organic anion transporter 1 (OAT1). The effects of SMS on in vitro XO activity and uric acid uptake were also evaluated. The components of SMS were identified using Ultra Performance Liquid Chromatography (UPLC).

Results

SMS-E reduced serum uric acid and creatinine concentrations, and elevated urine uric acid excretion. SMS-E lowered XO activities in both the serum and liver, and downregulated the expression of renal URAT1 and GLUT9 proteins. SMS-E reduced renal inflammation and IL-1β levels in both the serum and kidneys. SMS-E inhibited both in vitro XO activity and urate uptake in URAT1-expressing oocytes. Using UPLC, 25 ginsenosides were identified, all of which were present in higher levels in SMS-E than in SMS-W.

Conclusion

SMS-E exhibited antihyperuricemic effects by regulating XO activity and renal urate transporters, providing the first evidence of its applicability in the treatment of hyperuricemia and gout.

Eggshell Membrane Ameliorates Hyperuricemia by Increasing Urate Excretion in Potassium Oxonate-Injected Rats

Hyperuricemia is the primary cause of gouty arthritis and other metabolic disorders. Eggshell membrane (EM) is an effective and safe supplement for curing pain and stiffness connected with osteoarthritis. However, the effect of EM on hyperuricemia is unclear. This study determines the effects of EM on potassium oxonate-injected hyperuricemia. Uric acid, creatinine, blood urea nitrogen concentrations in the serum, and xanthine oxidase activity in the liver are measured. Protein levels of renal urate transporter 1 (URAT1), organic anion transporters 1 (OAT1), glucose transporter 9 (GLUT9), and ATP-binding cassette transporter G2 (ABCG2) in the kidney are determined with renal histopathology. The results demonstrate that EM reduces serum uric acid levels and increases urine uric acid levels in hyperuricemic rats. Moreover, EM downregulates renal URAT1 protein expression, upregulates OAT1 and ABCG2, but does not change GLUT9 expression. Additionally, EM does not change xanthine oxidase activity in the liver or the serum. EM also decreases uric acid uptake into oocytes expressing hURAT1. Finally, EM markedly reduces renal inflammation and serum interleukin-1β levels. These findings suggest that EM exhibits antihyperuricemic effects by promoting renal urate excretion and regulating renal urate transporters. Therefore, EM may be useful in the prevention and treatment of gout and hyperuricemia.

A 12-Week, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial for Evaluation of the Efficacy and Safety of DKB114 on Reduction of Uric Acid in Serum

This study sought to investigate the antihyperuricemia efficacy and safety of DKB114 (a mixture of Chrysanthemum indicum Linn flower extract and Cinnamomum cassia extract) to evaluate its potential as a dietary supplement ingredient. This clinical trial was a randomized, 12-week, double-blind, placebo-controlled study. A total of 80 subjects (40 subjects with an intake of DKB114 and 40 subjects with that of placebo) who had asymptomatic hyperuricemia (7.0–9.0 mg/dL with serum uric acid) was randomly assigned. No significant difference between the DKB114 and placebo groups was observed in the amount of uric acid in serum after six weeks of intake. However, after 12 weeks of intake, the uric acid level in serum of subjects in the DKB114 group decreased by 0.58 ± 0.86 mg/dL and was 7.37 ± 0.92 mg/dL, whereas that in the placebo group decreased by 0.02 ± 0.93 mg/dL and was 7.67 ± 0.89 mg/dL, a significant difference (p = 0.0229). In the analysis of C-reactive protein (CRP) change, after 12 weeks of administration, the DKB114 group showed an increase of 0.05 ± 0.27 mg/dL (p = 0.3187), while the placebo group showed an increase of 0.10 ± 0.21 mg/dL (p = 0.0324), a statistically significant difference (p = 0.0443). In the analysis of amount of change in apoprotein B, after 12 weeks of administration, the DKB114 group decreased by 4.75 ± 16.69 mg/dL (p = 0.1175), and the placebo group increased by 3.13 ± 12.64 mg/dL (p = 0.2187), a statistically significant difference between the administration groups (p = 0.0189). In the clinical pathology test, vital signs and weight measurement, and electrocardiogram test conducted for safety evaluation, no clinically significant difference was found between the ingestion groups, confirming the safety of DKB114. Therefore, it may have potential as a treatment for hyperuricemia and gout. We suggest that DKB114 as a beneficial and safe food ingredient for individuals with high serum uric acid. Trial registration (CRIS.NIH. go. Kr): KCT0002840.

Total glucosides of herbaceous peony (Paeonia lactiflora Pall.) flower attenuate adenine- and ethambutol-induced hyperuricaemia in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Herbaceous peony (Paeonia lactiflora Pall.) flower has been used widely in dietotherapy in China and other countries. It has good ethnopharmacological value in the treatment of various metabolic diseases. However, the molecular mechanisms by which it lowers serum uric acid are unknown. The development of pharmaceutical resources is very important. Here, we sought to elucidate the mode of action of herbaceous peony in terms of reducing uric acid levels.

AIM OF THE STUDY

In the present research, the effects of the total glucosides of herbaceous peony flower were investigated in a rat hyperuricaemia model. Another aim of the study was to clarify the mechanism by which herbaceous peony flower (TGPF) lowers serum uric acid levels.

MATERIALS AND METHODS

A hyperuricaemic rat model was induced via intragastric administration of 100 mg/kg adenine and 250 mg/kg ethambutol hydrochloride (EH) for 23 d. Then TongFengShu 600 mg/kg, allopurinol 42 mg/kg, or TGPF (50 mg/kg, 100 mg/kg, or 200 mg/kg) was administered 1 h after the adenine and EH treatments.

RESULTS

TGPF improved weight loss and decreased serum UA, XOD, MCP-1, TNF-α, Cr, and BUN in the rats with hyperuricaemic nephropathy. TGPF downregulated renal URAT1 and GLUT9, upregulated renal OAT1, and ameliorated histopathological changes in the thymus, spleen, and kidney.

CONCLUSION

TGPF is promising as a therapeutic agent against hyperuricaemia. It regulates the uric acid transporters and diminished serum uric acid levels, and alleviates renal pathology associated with hyperuricaemia.

Chrysanthemum indicum L.: A Comprehensive Review of its Botany, Phytochemistry and Pharmacology

Chrysanthemum indicum L. (C. indicum L.), a member of the Compositae family, is a perennial plant that has been used as a traditional medicine for more than 2000 years in China and is widely used for the treatment of Pemphigus, swelling, pain, and scrofula. To date, more than 190 chemical constituents have been isolated and identified from this plant, including flavonoids, terpenoids, phenylpropanoids, and phenolic acids. Numerous modern studies have shown that extracts or monomeric compounds from C. indicum L. have several pharmacological activities, such as anti-inflammatory anti-oxidation, antipathogenic microorganism, anticancer, immune regulation, and hepatoprotective effects. However, resource availability, the research on the mechanism, and quality control are still insufficient, which deserves further efforts. In this paper, the advances in botany, phytochemistry, and pharmacology of C. indicum L were reviewed. We hope that this review can provide important information for traditional Chinese medicine, phytochemistry, synthetic and medicinal chemistry researchers for making full use of C. indicum L. resource.

Uricostatic and uricosuric effect of grapefruit juice in potassium oxonate-induced hyperuricemic mice

The aim of this study was to examine the preventive action of grapefruit juice (GFJ) against potassium oxonate-induced hyperuricemic mice. The results showed that GFJ significantly (p < .05) inhibit the serum and hepatic xanthine oxidase enzyme, lower uric acid level, serum creatinine, uromodulin, and blood urea nitrogen levels to normal and lower inflammation related genes IL-1β, caspase-1, NLRP3, and ASC. Furthermore, histopathology analysis revealed that GFJ markedly improve the renal and intestinal morphology. The mRNA expression of urate transporter 1, glucose transporter 9 were downregulated, whereas ATP-binding cassette transporter (ABCG2) was upregulated in the GFJ-treated group. The results of immunohistochemistry revealed that the ABCG2 protein expression in the small and large intestine was significantly upregulated after the GFJ administration. These results suggested that GFJ can be used as a urate lowering agent and future mechanistic studies should be conducted. PRACTICAL APPLICATIONS: The results of current study indicated that utilization of GFJ as an anti-hyperuricemic agent for the treatment of hyperuricemia. This article will be very valuable for all those peoples which are directly or indirectly linked with this disease.

Anti-hyperuricemic effect of Alpinia oxyphylla seed extract by enhancing uric acid excretion in the kidney

BACKGROUND

Alpinia oxyphylla is a well-known traditional medicine used in China and Korea to treat intestinal disorders, urosis, diuresis, and chronic glomerulonephritis.

PURPOSE

We investigated the anti-hyperuricemic effects of Alpinia oxyphylla seed extract (AE), and the underlying mechanisms of action through in vitro and in vivo studies.

METHODS

We evaluated levels of uric acid in the serum and urine, the expression of renal urate transport proteins, and levels of inflammatory cytokines in potassium oxonate (PO)-induced hyperuricemic rats. Xanthine oxidase activity was analyzed in vitro, while cellular uric acid uptake was assessed in oocytes expressing the human urate transporter 1 (hURAT1). Moreover, the main components of AE were analyzed using UPLC.

RESULTS

In PO-induced hyperuricemic rats, 200 and 400 mg/kg of AE significantly decreased levels of uric acid in serum, while 400 mg/kg of AE increased uric acid levels in urine. AE did not inhibit xanthine oxidase in vitro; however, 1, 10, and 100 μg/ml of AE significantly decreased uric acid uptake into oocytes expressing hURAT1. Furthermore, 400 mg/kg of AE increased levels of organic anion transporter (OAT) 1 protein, while 200 and 400 mg/kg of AE decreased the protein content of urate transporter, URAT1 and inflammatory cytokines in the kidneys. Nootkatone was identified as one the main chemical components in AE from UPLC analysis.

CONCLUSIONS

These findings suggest that AE exerts anti-hyperuricemic and uricosuric effects, which are related to the promotion of uric acid excretion via enhanced secretion and inhibition of uric acid reabsorption in the kidneys. Thus, AE may be a potential treatment for hyperuricemia and gout.

Antihyperuricemic and anti-gouty arthritis activities of Aurantii fructus immaturus carbonisata-derived carbon dots

Aim: To explore the antihyperuricemia and anti-gouty arthritis activities of Aurantii fructus immaturus carbonisata-derived carbon dots (AFIC-CDs). Materials & methods: The AFIC-CDs were characterized using transmission electron microscopy; high-resolution transmission electron microscopy; ultraviolet, fluorescence, Fourier-transform infrared and x-ray photoelectron spectroscopy; high-performance liquid chromatography; and x-ray diffraction. Antihyperuricemia and anti-gouty arthritis activities of AFIC-CDs were explored in vivo and in vitro. Results: The AFIC-CDs diameter ranged from 1.1 to 4.4 nm, with a yield of 7.2%. AFIC-CDs reduced serum uric acid by inhibiting xanthine oxidase activity in hyperuricemia rats and inhibited xanthine oxidase activity in vitro. AFIC-CDs improved gouty arthritis induced by monosodium urate crystals in vivo and in vitro. Conclusion: AFIC-CDs may be a potential treatment for gout.