Abstract: AIM:To investigate the analgesic effect of Yatongling Spray and to provide an experimental basis for its clinical use. METHODS:Experimental pain models of mice were established to investigate the analgesic effect of Yatongling Spray. (1)Writhing test: Fifty Kunming mice were divided into 5 groups(n =10 in each group, 5 male and 5 female). The mice were gavaged with physiological saline 10 mL/kg in control group, with Yatongling Spray 0. 36, 1. 08, 3. 24 g/kg in Yatongling Spray groups, and with aspirin 0. 4 g/kg in aspirin group(positive control group). Drugs were given once a day for 10 d. After the last administration, the writhing response times of mice were recorded during 5-20 min after intraperitoneal injection of acetic acid. (2) Hot plate test: A hot plate with a temperature of (55 ±1) ℃was used to test the pain threshold of mice. The time from putting on the hot plate to licking postpedes was defined as pain threshold time of mice. Fifty female mice with pain threshold times from 5 to 30 s were divided into 5 groups as described above. The pain threshold time was recorded after drug administration for 10 d. RESULTS:(1) Compared with control group, the writhing response times of mice were significantly decreased with inhibition rates of 25. 6%, 30. 6% and 43. 5% after gavaged with Yatongling Spray 0. 36, 1. 08 and 3. 24 g/kg for 10 d(P < 0. 05, P <0. 01), respectively. (2) The pain thresholds were not significantly different among the groups before drug administration(P >0. 05). After gavaged with Yatongling Spray 0. 36, 1. 08 and 3. 24 g/kg for 10 d, the pain thresholds were significantly prolonged compared with that of control group(P <0. 05, P < 0. 01). CONCLUSION:Yatongling Spray has an analgesic effect on experimental pain of mice.

Key words: Yatongling Spray, mice, analgesic effect, writhing response, hot plate test