Effect of rosuvastatin on hyperuricemic rats and the protective effect on endothelial dysfunction

The Effect of Statin Therapy on Serum Uric Acid Levels: A Systematic Review and Meta-analysis

BACKGROUND

Elevated concentrations of serum uric acid (SUA) are associated with several conditions, including cardiovascular disease. The present study aimed to estimate the impact of statin therapy on SUA levels through a systematic review and meta-analysis of clinical trials.

METHODS

PubMed, Embase, Web of Science, and Scopus were searched on January 14, 2022, to identify eligible clinical trials. The intervention group received statins as monotherapy or in combination with other drugs, and the control group received non-statins or placebo. Studies reporting SUA levels before and after treatment were selected for further analysis. Finally, the data were pooled, and the mean changes in SUA, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides were reported.

RESULTS

Out of 1269 identified studies, 23 were included in the review. A total of 3928 participants received statin therapy, and 1294 were included in control groups. We found a significant reduction in SUA levels following statin therapy (mean difference (MD) = -26.67 μmol/L with 95% confidence interval (CI) [-44.75, -8.60] (P =0.004)). Atorvastatin (MD = -37.93 μmol/L [-67.71, -8.15]; P < 0.0001), pravastatin (MD = -12.64 μmol/L [-18.64, -6.65]; P < 0.0001), and simvastatin (MD = -5.95 μmol/L [-6.14, -5.80]; P < 0.0001), but not rosuvastatin, were significantly associated with a reduction in SUA levels. An analysis comparing different types of statins showed that pravastatin 20-40 mg/day could significantly reduce SUA when compared to simvastatin 10-20 mg/day (-21.86 μmol/L [-36.33,-7.39]; P =0.003).

CONCLUSION

Statins were significantly associated with a decrease in SUA levels, particularly atorvastatin, which was found to be most effective in lowering SUA. Atorvastatin may be the most appropriate cholesterol-lowering agent for patients with or at risk of hyperuricemia.

Effects of rosuvastatin on serum glucose and insulin in hyperuricemic rats

Background

Hyperuricemia is a state in which the serum levels of uric acid (UA) are elevated. This study was to determine the roles of rosuvastatin in fasting blood glucose (FGB) and insulin levels in hyperuricemic rats.

Methods

Thirty-six Sprague-Dawley (SD) rats were randomized divided into the control, model and rosuvastatin groups: the control was given no intervention, the model group was established by administrating yeast extract powder and oxonic acid potassium salt, and the rosuvastatin group was given intravenous administration of rosuvastatin for 28 days in hyperuricemic rats. Serum uric acid (SUA), fasting blood glucose (FBG), fasting blood insulin (FBI), glutamic acid decarboxylase antibody (GADA), oral glucose tolerance test (OGTT) levels, and the ultrastructure of pancreatic β-cells were measured. Also, homeostasis model assessment of insulin resistance (HOMA-IR) scores was computed in three groups.

Results

Compared to the model group, SUA were decreased, while the FBG, GADA, OGTT and HOMA-IR at week 4 were significantly increased in rosuvastatin group. However, FBI was not significantly changed between three groups. It was also showed that the structure of pancreatic β-cells was damaged and the number of β-cells was changed in hyperuricemic rats while they were aggravated in rosuvastatin group.

Conclusion

Rosuvastatin has roles in inducing FGB, GADA, OGTT and pancreatic β-cells damage in hyperuricemic rats.

Harnessing hyperuricemia to atherosclerosis and understanding its mechanistic dependence

Atherosclerosis is regarded as the disease of the arterial vasculature. The main characteristics of atherosclerosis are the abnormal accumulation of lipids, increased inflammatory cells, matrix deposits, and proliferation of smooth muscle cells. Diabetes mellitus, obesity, and hyperlipidemia are the most studied risk factors of atherosclerosis. One least studied risk factor is the uric acid (UA), a high UA in circulation is interlinked with many pathological processes. Several epidemiological studies suggest elevated UA levels as an essential biomarker in the forecast of several cardiovascular diseases. Available evidence claims that UA upholds the atherosclerosis process via disturbing lipid metabolism, reducing the nitric oxide synthesis in endothelial cells, promoting the proliferation of vascular smooth muscle cells, and overwhelms inflammation. In endothelial dysfunction and coronary artery lesions, UA is considered as an independent predictor. The updated studies on the involvement of hyperuricemia in atherosclerosis prove that treatment with xanthine oxidase (XO) inhibitors not just benefits the treatment of hyperuricemia but also reduces the burden of atherosclerosis to a greater extent. In this review, we highlight how the hyperuricemia affects vascular integrity, causes atherosclerosis, and the mechanism of action of XO inhibitors on atherosclerosis.

Tu-Teng-Cao Extract Alleviates Monosodium Urate-Induced Acute Gouty Arthritis in Rats by Inhibiting Uric Acid and Inflammation

Gouty arthritis is an inflammatory joint disease closely related to hyperuricemia. It is characterized by deposition of monosodium urate crystals in the joints, resulting in an intense inflammatory process and pain. Control of hyperuricemia and anti-inflammation treatments are the main therapeutic approaches. However, the commonly used drugs for inhibiting uric acid and acute gouty arthritis have obvious gastrointestinal and renal toxicity; thus, there is an urgency to develop new alternative therapeutic drugs. An extract of Tu-Teng-Cao (TTC), a compound drug used in traditional Chinese medicine, has been widely applied to the clinical treatment of arthritis. In this study, we investigated the therapeutic effects of TTC on gouty arthritis. In this study, an animal model of acute gouty arthritis with hyperuricemia was established using potassium oxonate and monosodium urate crystals. After treatment with TTC, the results showed obvious therapeutic effects on the rat model of acute gouty arthritis. The treatment significantly attenuated the degree of ankle swelling, inflammation, and dysfunction index, and the levels of proinflammatory cytokines. In addition, TTC has significant antihyperuricemia activity in rats with hyperuricemia induced by potassium oxonate. Histological evaluation showed that TTC relieved pathological damage in rats with acute gouty arthritis induced by monosodium urate crystals. All the groups treated with TTC showed improvement in cartilage degeneration, cell degeneration, synovial hyperplasia, and inflammatory cell invasion in the ankle joint of rats. TTC significantly alleviated swelling, inflammation, and bleeding of the renal corpuscle and convoluted tubules of rats. The results of this study suggest that TTC is capable of treating gouty arthritis and decreasing ankle injury through the control of uric acid and inflammation.

Construction and expression of recombinant uricase‑expressing genetically engineered bacteria and its application in rat model of hyperuricemia

At present, the treatment of hyperuricemia is designed primarily to decrease the production of uric acid using xanthine oxidase inhibitors; however, the therapeutic effect is not satisfactory. Therefore, the key to the successful treatment of hyperuricemia is to increase the excretion of uric acid. The aim of present study was to construct uricase-expressing genetically engineered bacteria and analyze the effects of these engineered bacteria on the lowering of uric acid levels in a rat model of hyperuricemia. The uricase expression vector was constructed by gene recombination technology and transfected into Escherichia coli. The expression and activity of uricase were analyzed by SDS-PAGE analysis and Bradford assay. The water consumption, food intake, body weight, eosinophil count and intestinal histology, in addition to the levels of serum uric acid (SUA) and allantoin in the feces of the rats, were assessed. The intestinal contents of the rats were analyzed by 16S rDNA sequencing technology. The results demonstrated that uricase-expressing genetically engineered bacteria secreted active uricase. All rats exhibited a natural growth trend during the entire experiment, and the SUA of hyperuricemic rats treated with uricase-expressing engineered bacteria was significantly decreased. In conclusion, these results indicate that uricase secreted by recombinant uricase-expressing genetically engineered bacteria served an important role in decreasing SUA levels in a rat model of hyperuricemia.

Telmisartan Attenuates Uric Acid-Induced Epithelial-Mesenchymal Transition in Renal Tubular Cells

We examined whether and how uric acid induces epithelial to mesenchymal transition (EMT) in renal tubular cells, along with the mechanism by which telmisartan acts on uric acid-induced renal injury. Rat renal proximal tubular epithelial cells (NRK-52E) were exposed to various concentrations of uric acid in the presence or absence of telmisartan. Treatment with uric acid increased the expression of α-SMA, decreased the expression of E-cadherin, and promoted EMT in NRK-52E cells. Uric acid treatment also led to increased endothelin-1 (ET-1) production, activation of extracellular-regulated protein kinase 1/2 (ERK1/2), and the upregulation of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4). Use of ET-1 receptor inhibitor (BQ123 or BQ788) could inhibit uric acid-induced EMT in NRK-52E cells. Pretreatment with the ERK inhibitor (U0126 or PD98059) suppressed the release of ET-1 and EMT induced by uric acid. Additionally, pretreatment with a traditional antioxidant (diphenylene iodonium or apocynin) inhibited the activation of ERK1/2, release of ET-1, and uric acid-induced EMT in NRK-52E cells. These findings suggested that uric acid-induced EMT in renal tubular epithelial cells occurs through NADPH oxidase-mediated ERK1/2 activation and the subsequent release of ET-1. Furthermore, telmisartan (10² nmol/L to 10⁴ nmol/L) inhibited the expression of NOX4, intracellular reactive oxygen species (ROS), activation of ERK1/2, and the release of ET-1 in a dose-dependent manner, thereby preventing uric acid-induced EMT in NRK-52E. In conclusion, telmisartan could ameliorate uric acid-induced EMT in NRK-52E cells likely through inhibition of the NADPH oxidase/ERK1/2/ET-1 pathway.

Effects of Chicory on Serum Uric Acid, Renal Function, and GLUT9 Expression in Hyperuricaemic Rats with Renal Injury and In Vitro Verification with Cells

Hyperuricaemia (HUA) is an independent risk factor for chronic kidney disease. Urate crystals are deposited in the kidney and can cause renal tubular interstitial fibrosis, leading to renal dysfunction. Chicory extract (hereafter referred to as chicory) clearly reduced serum uric acid levels in rats with HUA induced by 10% fructose. This is the first study to observe the effect of chicory on serum uric acid levels and renal function in rats with HUA and renal injury. In vivo studies using hyperuricaemic rats with renal injury induced by yeast and adenine demonstrated that chicory decreased serum uric acid level, and its effect of delaying the progression of kidney injury was better than that of benzbromarone. In vitro cell experiments showed that this effect is related to the inhibition of GLUT9 protein expression in renal tubules and that lowering blood uric acid concentrations is one of the factors that alleviates renal damage. The results of this study indicate that chicory can be used as an alternative for alleviating renal dysfunction in hyperuricaemia.

Effect and Mechanism of ShiZhiFang on Uric Acid Metabolism in Hyperuricemic Rats

Objective

To explore the effect and mechanism of ShiZhiFang on uric acid metabolism.

Methods

40 rats were divided into normal group, model group, ShiZhiFang group, and benzbromarone group. The hyperuricemic rat model was induced by yeast gavage at 15 g/kg and potassium oxonate intraperitoneal injection at 600 mg/kg for two weeks. During the next two weeks, ShiZhiFang group rats were given ShiZhiFang by gavage, and benzbromarone group rats were given benzbromarone by gavage. The serum uric acid, creatinine, blood urea nitrogen, XOD activity, urinary uric acid, urinary β₂-MG, and histopathological changes were observed in the rats of each group after treatment.

Results

The hyperuricemic model was established successfully and did not show the increase of serum creatinine and blood urea nitrogen. Compared with the model group, the serum uric acid, serum XOD activity, and urinary β₂-MG were significantly decreased (p < 0.05), and 24 h urinary uric acid excretion was significantly decreased (p < 0.01) in ShiZhiFang group, whereas the two treatment groups were of no statistical significant in above indicators (p > 0.05); renal histopathology showed that the lesions in two treatment groups were reduced compared to the model groups. The gene and protein expression of uric acid anion transporters rOAT1 and rOAT3 in the kidney was significantly higher than that in model group (p < 0.01).

Conclusion

The model is suitable for the study of primary hyperuricemia. The mechanisms of ShiZhiFang on uric acid metabolism in hyperuricemic rats may be involved in reducing the activity of serum XOD and promoting the transcription and expression of rOAT1 and rOAT3 in the kidney.