Simiao pill ameliorates renal glomerular injury via increasing Sirt1 expression and suppressing NF-κB/NLRP3 inflammasome activation in high fructose-fed rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Simiao pill is one of the most frequently prescriptions in traditional Chinese medicine to treat hyperuricemia and gout. This study was to investigate the protective effects of Simiao pill on renal glomerular injury in a rat model of high fructose intake.

MATERIALS AND METHODS: Sprague-Dawley male rats were given 10% fructose in drinking water and standard laboratory chow for 4 weeks to induce hyperuricemia and metabolic syndrome. Then fructose-fed animals were randomly divided into four groups receiving water, Simiao pill (78.87 and 157.74 mg/kg) and allopurinol (5mg/kg) daily for next 6 weeks, respectively. Serum levels of uric acid, creatinine, triglyceride, total cholesterol, low density lipoprotein, blood urea nitrogen, insulin, as well as urinary albumin were measured. Oral glucose tolerance test (OGTT) was carried out. Kidney pathological changes were detected using periodic-acid schiff-stained (PAS) staining and transmission electron microscopy (TEM) analysis. Glomerular protein levels of nephrin, podocin, CD2-associated protein (CD2AP), interleukin (IL)-1β, sirtuin 1 (Sirt1), nuclear factor kappaB (NF-κB) and pyrin domain containing 3 (NLRP3) inflammasome were measured by Western blot.

RESULTS: Simiao pill effectively restored high fructose-induced hyperuricemia and metabolic syndrome in rats. Simiao pill significantly increased protein levels of nephrin, podocin and CD2AP in renal glomeruli, improved renal inflammatory cell infiltration into interstitium and glomerular injury in high fructose-fed rats with reduction of urine albumin levels. Furthermore, Simiao pill up-regulated Sirt1 protein levels and suppressed NF-κB/NLRP3 inflammasome activation to reduce IL-1β in renal glomeruli of high fructose-fed rats.

CONCLUSIONS: The renal protective effects of Simiao pill may be associated with up-regulation of Sirt1 expression and suppression of NF-κB/NLRP3 inflammasome activation to reduce renal glomerular injury in high fructose-fed rats with metabolic syndrome.