Toxicity assessment of Leonuri Herba aqueous extract orally administered to rats for 13 consecutive weeks.

Ethnopharmacological Relevance: The Leonuri Herba has been traditionally used for women's disease in Asian countries.

Aim Of The Study: The objective of the present study was to evaluate the subchronic toxicity of Leonuri Herba aqueous extract in male and female F344 rats.

Material And Methods: Leonuri Herba aqueous extract was administered orally once daily at dose levels of 0, 125, 250, 500, 1000 and 2000 mg/kg/day for 13 weeks. Toxicological assessment was performed including mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination.

Results: There were no treatment related differences in clinical signs, urinalysis, hematology and serum chemistry, except for a histopathologic examination. The squamous cell hyperplasia in the forestomach was observed in both sexes of rats given 2000 mg/kg/day of Leonuri Herba aqueous extract.

Conclusion: In conclusion, the NOAEL (No Observed Adverse Effect Level) for Leonuri Herba aqueous extract was determined as 1000 mg/kg/day in both sexes of rats under the present experimental conditions. And the acceptable daily intake value for Leonuri Herba aqueous extract was calculated to be 10mg/kg body weight per day using a safety factor of 100 to the NOAEL.