Abstract: Objective To observe the toxicity of arctigenin in SD rats for 28 days by oral administration, and provide reference for clinical medication. Methods 120 healthy SD rats, half male and half female, were randomly divided into 4 groups: solvent control (0.5% sodium carboxymethylcellulose solution) group, arctigenin low-, mid-, and high-dose (12, 36, and 120 mg·kg-1) groups, 30 in each group. Dose volume was 10 mL·kg^-1, with oral administration 1 time per day for 28 days, and observed for 4 weeks after the last administration. During the experiment, the general state of animals was observed daily, and food consumption was weighed weekly. Body mass was weighed twice per week in administration period and 1 time per week in recovery period. At the end of the administration period and 4 weeks after drug withdrawal, the related indexes including urine routine, blood routine, blood coagulation index, blood biochemistry and serum electrolyte were detected, then the rats were dissected and histopathologic examination was carried out. Results Oral administration for 28 days and 4 weeks after drug withdrawal, general state of the rats in arctigenin 12, 36, and 120 mg·kg^-1 groups were normal, and no abnormal change in food consumption, urine routine, blood routine, blood coagulation index, or serum electrolyte (P>0.05) was found. In the first week of administration, the body mass of the female rats in 120 mg·kg^-1 group increased slowly compared with the solvent control group (P<0.05); at the end of the recovery period, the value of CREA slightly elevated in 12 mg·kg^-1 group, and the weight of brain of the male rats in 12 mg·kg^-1 group increased (P<0.05). At the end of the administration and recovery period, a small number of mild pathological changes in heart, liver and other organs or tissues were observed in each group under an optical microscope, and there were no differences in the number or severity of lesions among the groups (P>0.05). Conclusion In this study, we haven’t found any abnormal changes related to the toxicity of arctigenin. So arctigenin by oral administration doesn’t have any obvious toxicity to SD rats.

Key words: arctigenin, rat, repeated dose toxicity