Evaluation of safety of the herbal formula Ojeok-san: acute and sub-chronic toxicity studies in rats.

Aim Of The Study: Ojeok-san (OJS; wuji powder in China and goshaku-san in Japan), a widely used herbal formula in traditional Korean medicine and Japanese herbal medicine (Kampo medicine), has been used to treat common cold and illnesses including fatigue and gastrointestinal disorders, but there is very little information on its safety. To provide information on the safety of OJS, we evaluated its acute and sub-chronic toxicity in rats.

Materials And Methods: The single and sub-chronic toxicity of OJS was examined using male and female Sprague-Dawley rats. The rats were treated with the OJS extract orally at the highest dose level of 2000 mg/kg/day body weight. After single administration, signs of toxicity were observed every hour for the first 6h and every day for two weeks. In the sub-chronic toxicity study, OJS was administered for 13 weeks. Mortality, clinical signs, body weight changes, food and water consumption, ophthalmologic findings, urinalysis, hematological and biochemical parameters, gross findings, organ weights and histological markers were monitored during the study period.

Results: We found no mortality and no abnormality in clinical signs, body weight, and necropsy findings for any of the animals in the acute and sub-chronic toxicity study following oral administration of OJS.

Conclusion: OJS may not have any single dose toxicity. The lethal dose with a 50% mortality rate (LD(50)) was over 2000 mg/kg. The no-observed adverse effects level (NOAEL) was considered to be 2000 and 1000 mg/kg/day for male and female rats, respectively.