Subchronic toxicity study of Coptidis rhizoma in rats.

ETHNOPHARMACOLOGICAL RELEVANCE:Coptidis Rhizoma (CR) is a medical herb from the family Ranunculacease that has been used to treat gastroenteritis, dysentery, diabetes mellitus, and severe skin diseases. AIM OF THE STUDY:To evaluate the no-observed-adverse-effect level (NOAEL) and the toxicity of CR, following repeat oral administration to rats for 13 weeks. MATERIALS AND METHODS:CR was administered by oral gavage to groups of rats (n=10/group, each sex) at dose levels of 0 (control), 25, 74, 222, 667 or 2000 mg/kg/day 5 times per week for 13 weeks. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, urinalysis, vaginal cytology and sperm morphology, organ weights, gross and histopathological findings were compared between control and CR groups. RESULTS:Urinalysis showed a significant increase in N-acety1-β-glucosaminidase in males in the 2000 mg/kg/day group (P<0.01). However, no mortality or remarkable clinical signs were observed during this 13-week study. No adverse effects on body weight, food consumption, hematology, serum chemistry, organ weights, gross lesion, histopathology, vaginal cytology, sperm motility, or deformity were observed in the males or female rats treated with CR. CONCLUSIONS:On the basis of these results, the NOAEL of CR is determined to be 667 mg/kg/day for males and 2000 mg/kg/day for females.