Abstract: Objective To explore the acute toxicity of anti-hypertensive drug proline-Danshensu borneol ester-in mice, and to evaluate its safety. Methods Twenty-four mice were randomly divided into the test group and control group. The maximum tolerated dose (MTD) was determined via single intragastrical administration of the maximal concentration of proline Danshensu borneol ester (150 mg·mL^-1). Toxic reactions, body weight and intakes of foods and water were observed for seven consecutive days until the mice were sacrificed. Visceral changes were observed and index of the heart, liver, kidney and lung were recorded. Pathological histology was observed via HE staining. Results There was no death of mice after intragastrical administration of different concentrations of proline Danshensu borneol ester. Compared with the control group, the daily activities, body weight and intakes of foods and water in the test group of mice were not significantly different (P>0.05), so were the indexes of the liver, kidney or lung (P>0.05). The heart indexes of male mice in the test group were not significantly different from those of the control group (P>0.05), but the heart indexes of female mice were significantly decreased (P<0.05) and myocardial cells were disorderly. Conclusion The MTD of proline Danshensu borneol ester in mice is orally 3 000 mg·kg^-1, which leads to low toxicity in mice.

Key words: proline Danshensu borneol ester, hypertension, acute toxicity, median lethal dose, maximum tolerated dose, safety, mice, intragastric administration