Introduction: Considering the evidence which show the effect of herbal medicine on nephrolithiasis treatment, the aim of this study was to evaluate the efficacy of ethanolic extract of Smyrnium cordifolium Boiss root on prevention of calcium oxalate nephrolithiasis in rats.

Materials & methods:  Thirty-two female Wistar albino rats were randomly divided into 4 groups. Normal control received water and other three groups received ethylene glycol (EG) (1% v/v) in distilled water for 28 days. Extract was given 200 mg/kg and 400 mg/kg orally in distilled water for 28 days in groups III and IV. The urea, uric acid and creatinine were measured on 28th day. 24 hr urinary volume and oxalate were measured on day 0 and 28.

Findings: EG significantly had increased serum creatinine, urea and uric acid in comparison to the normal control. Whereas serum creatinine, urea and uric acid were reduced non-significantly in groups III and IV in comparison to EG group. Smyrnium cordifolium extract significantly increased urinary volume but decreased urine oxalate level compared to EG group (P<0.05).

Discussion & Conclusions: This study showed that Smyrnium cordifolium extract was able to reduce urine oxalate in the rat. Therefore, the beneficial action of extract on human kidney stones may be suggested. However, further studies must clarify the mechanism.