Keywords: 
• imperatorin /
• acute toxicity /
• safety pharmacology

Abstract: Objective To determine the acute toxicity of imperatorin on rats and mice, and the influence of imperatorin on the nervous system of mice and the cardiovascular and respiratory systems of beagle dogs. Methods intraperitoneal injection (ip) and intragastric administration (ig) were performed to mice and ig to rats to determine the acute toxicity of imperatorin. In safety pharmacology experiments, ip of imperatorin was performed to mice in single doses of 50, 100, and 200 mg/kg to observe its influence on the nervous system of mice (including locomotor activity, pole climbing ability, and collaborative hyposis experiment of threshold dose of sodium pentobarbital, etc.). Oral administration (po) of imperatorin was also performed in single doses of 25, 50, 100 mg/kg to beagle dogs to observe its influence on the cardiovascular and respiratory systems of dogs (including ECG, blood pressure, heart rate, and breathing indexes, etc.). Results The LD₅₀ of imperatorin to mice is 988.5 mg/kg by ig and 603.3 mg/kg by ip, and to rats is 3188.7 mg/kg by ig. No significant effects on the nervous system of mice were observed by single ip of imperatorin. And no significant effects on the cardiovascular and respiratory systems of beagle dogs were observed by single po of imperatorin. Conclusion Imperatorin had a wide range of safety application, and its toxicity was relatively easy to control. The antihypertensive effects of imperatorin on normal animals (including mice, rats and dogs) were not significant, therefore it had a great possibility in clinical application.