Effect Of Rosmarinic Acid On Calcium Oxalate Renal Stone Formation In Rats

Objective To investigate rosmarinic acid's impact on calcium oxalate renal stone formation in rats and study the pharmacological actions and mechanisms of rosmarinic acid too.Methods The model rats with renal calcium oxalate stone formation were induced by ig 1% ethylene glycol[V/V] and 2% ammonium chloride[W/V] for 28 days, and application of different dose of rosmarinic acid as the interference factor, renal stone kernels as positive control drug. Use automatic biochemical analyzer to detect the urinalysis biochemistry of rats in each group in different periods and High Performance Liquid Chromatography(HPLC) to determine the content of ethanedioicacid and citric acid in urine of rats. Examine the blood biochemistry after 28d. Dissect the rats and study their kidney, use HPLC to determinethe content of ethanedioic acid and citric acid in the kidney tissue. Use atomic absorption spectroscopy to determine the content of calcium in kidney. Hematoxylin-eosin staining to observe the renal pathological changes and Von-Kossa's staining to observe renal calcium oxalate crystal morphology distribution. Use immunohistochemical methods to observe the expression ofinter-trypsin inhibitor (IαI) in kidney tissues.Results Compare the creatinine, uric acid, oxalic acid, Ca2+ content inurine; BUN, Cr, Ca2+ content in serum, Ca2+ content in kidney tissue of both rosmarinic acid middle-dose(0.05g·Kg-1) and high-dose group(0.1g·Kg-1) to the renal stone group, there are significant difference (P <0.05); rosmarinic acid low-dose group and the renal stone model group showed no significant difference (P> 0.05). Rosmarinic acid middle-dose and high-dose group had significant difference (P <0.05) in BUN, Cr, Ca2+ content of serum, and they both had difference in renal pathological changes, calcium oxalate crystal morphology and the expression of IαI in kidney tubules epithelial cell compared to renal stone group.Conclusion Rosmarinic acid can inhibit renal calcium oxalate stone formation in rats, and that's a dose-response relationship.