Acute and sub-acute oral toxicity studies of standardized extract of Nasturtium officinale in Wistar rats.

Nasturtium officinale (watercress) is a perennial dicotyledonous plant, rich in vitamins, minerals and chemical compounds. The leaves of this plant, which contain glucosinolate, are used for its diuretic and hypoglycemic effects. The purpose of the study was to investigate the safety of the standardized extract of Nasturtium officinale (SENO) with phenylethyl glucosinolate 5.0 mg/ml-1, using acute and sub-acute oral dosage in Wistar rats. High-Performance Liquid Chromatography (HPLC) analyzed the chemical composition, from aerial parts of watercress. In the acute toxicity study, dose estimated was LD50 in the range of 2000-5000 mg/kg, signs of mortality and toxicity on female rats were observed for 14 days, after single doses of 2000 and 5000 mg/kg. In the sub-acute study, female and male rats, age 10 weeks, were supplemented at doses of 250, 500 and 1000 mg/kg for 28 days. On the 29th day, rats were fasted, anesthetized, euthanized, then their blood used for hematological and biochemical evaluation. No significant changes in general behavior were reported regarding the acute study, while the sub-acute study demonstrated no toxicity of the hematopoietic and biochemical systems. The results showed that SENO at dosage up to 5000 mg/kg in acute study was safe, and NOAEL (no-observed-adverse-effect levels) in the sub-acute, was up to 1000 mg/kg.