Abstract: OBJECTIVE: To evaluate the safety of Oroxylumindicum(L.) Vent extract administered for 26 weeks in Wistar rats.METHODS: Oroxylumindicum(L.) Vent extract was administrated to male and female rats by gavage once daily at doses of 54, 225, and450 mg·kg-1·d-1.The rats were sacrificed after administration for13 weeks and 26 weeks. Part of the rats in each group were allowed to recover for 4 weeks after 26-week administration. Systematic examinations including haematology, urology, blood biochemistry and histomorphology were performed at the end of13, 26 weeks of administration and 4 weeks of recovery.RESULTS: No treatment related adverse effect shappened on rats' general status, body weight, food consumption, urinary index and histomorphologyexamination. Although during the administration,in some rats of extract's groups, the value of Red blood cell count(RBC), white blood cell counts(WBC), hemoglobin(HGB), haematocrit(HCT) and K iron were decreased, and biochemistry index,such as glucose(GLU), triglyceride(TG), alanine transaminase(ALT) and blood urea nitrogen(BUN)were increased, the above parameters were within the normal ranges and all returned to baseline after the drug stopping for 4 weeks.CONCLUSION: The administration of Oroxylumindicum(L.) Vent extractat levers up to 450 mg/kg(equals to 75 times of clinical dose) is well toleratedfor both genders without significant toxicity within the administration duration in this study.

Key words: Oroxylumindicum(L.) Vent, Safety, Chronic toxicity, Rats