Effect of beta-cyclodextrin encapsulated gallic acid from Polygonum equisetiforme L. on kidney stones produced by ethylene glycol and ammonium chloride in rats

Abstract

In this study, we examined the effects of encapsulated ellagic acid from Polygonum equisetiforme (PE) on kidney stones. Rats in this study randomly divided into 4 groups: Group I (control), Group II (disease group), Group III (low dose-100 mg/kg) and Group IV (high dose- 400 mg/kg). Kidney stones induced by adding 0.75% Ethylene Glycol (EG) + 2% Ammonium Chloride (AC) to drinking water and treatment groups received PE extract by gavage for 14 days. Exposure to EG/AC resulted in a significant decrease in SOD and GPx and an increase in creatinine levels. The treatment reversed the decreased GPx, SOD and the increased the creatinine levels. Histopathological findings are compatible with the ELISA results. There was no pathologic findings were detected in Group I. In Group II, the presence of calcium oxalate crystalloids in the kidney tissues as well as tubular dilatation and interstitial inflammation confirmed the formation of kidney stones. These histopathological findings in the kidneys were reversed by the PE extract. On the other hand, the histopathological results of liver tissues were different from kidney tissues. While no pathological findings were found in group I, a trace amount of damage was observed in the disease group. In addition, while a mild portal inflammation occurred in the low-dose treatment group, moderate portal inflammation and mild interface hepatitis occurred in the high-dose treatment group. This finding may restrict usability of the phenolic extract of PE in the treatment of kidney stone except of low doses of the PE extract.