Animals and treatments

Adult Wistar rats (15 males and 15 females, body weight of 200–250 g) were purchased from the Laboratory Animal Center at the Southern Medical University (Guangzhou, China). The rats were housed in a 12-h light-dark cycle and given water and food ad libitum. All experiments were conducted under the guidance of the care and use of laboratory animals issued by the Ministry of Science and Technology of the China (10). A modified version of the NTG model described by Lai (11) was used. The rats were randomly divided into three groups (n=10/group): control, migraine (model), and migraine + ligustrazine (TMP). The rats were treated for 7 consecutive days with the daily doses of ligustrazine hydrochloride injections (group TMP, 16 mL/kg/d, 10 mL sterile saline, 40 mg ligustrazine hydrochloride) or normal saline (control and model groups). At 10 min after administration of the last injection, 15 mg/kg body weight of NTG was subcutaneously administered into rat buttocks to establish an experimental migraine model (11) in the model group and TMP group.

All drug solutions were freshly prepared on the day of use. All rats were weighed before behavioral observation throughout the study. No significant differences were found in weight gain between rats treated with ligustrazine. Experiments were performed under a project license (No.: 20170301006) granted by the Laboratory Animal Ethics Committee Jinan University, in compliance with the guidance of the care and use of laboratory animals issued by the Ministry of Science and Technology of the China. A protocol was prepared before the study without registration.