Safety assessment of So-cheong-ryong-tang: subchronic toxicity study in Crl:CD Sprague Dawley rats.

So-cheong-ryong-tang, an oriental herbal formula, is used in Korea for treating pulmonary disorders, including asthma, bronchitis and allergic diseases. The objective of the present study was to investigate the potential adverse effects, if any, of subchronic administration of So-cheong-ryong-tang aqueous extract (SCRT) in male and female rats. In the present study, 0, 1,000, 2,000 and 5,000 mg/kg/day of SCRT was administered to Crl:CD Sprague Dawley rats (10/gender/group) for 13 weeks via oral gavage. Administration of the SCRT did not result in any mortality. There were no clinical or ophthalmological signs, changes in urinalysis, body weight, food consumption, gross findings, hematology, serum biochemistry, organ weight or histopathology attributable to the administration of SCRT. Any alterations noted were incidental and consistent with those historically observed in the age and strain of rats used in the present study. Based on the results of the present study, the no observed adverse effect level for SCRT under the present experimental conditions was determined to be 5,000 mg/kg/day, the highest dose assessed, for both genders.