Analgesic activity of DaChuanXiongFang after intranasal administration and its potential active components in vivo

Abstract

Ethnopharmacological relevanceDaChuanXiongFang was a well-known formula originated from Jin Dynasty, China. It has been used in both China and Japan to treat migraine. In the present study, the analgesic and sedative efficacy of DaChuanXiongFang ethanol extract (DCXFEE) after intranasal administration was tested and compared with that by intragastric route. Materials and methodsThree mice experimental models: acetic acid-induced writhing response test, hot-plate latent pain response test and pentobarbital-induced sleep model were used to evaluate DCXFEE activity. To further explore the in vivo potential active components of DCXFEE that contribute to the difference of activity induced by different administration route, ultra performance liquid chromatography–mass spectrometer (UPLC–MS) was utilized to analyze components in rat brain after given DCXFEE (60mg/kg). ResultsDCXFEE showed analgesic efficacy after intranasal administration (15, 30 and 60mg/kg) in acetic acid-induced writhing response in mice. While after intragastric administration, DCXFEE only showed analgesic efficacy at high dose (60mg/kg). Moreover, the analgesic potency was weaker after intragastric administration compared with that after intranasal administration at the same dose (60mg/kg). Similar results were obtained in hot-plate latent pain response test in mice. DCXFEE (60mg/kg) had no sedative effect after intranasal and intragastric administration. No components originated from DCXFEE were identified in rat brain 15min after oral administration. One major parent component ligustilide was detected in rat brain after intranasal administration. ConclusionThese data demonstrate that DCXFEE had faster onset of action as well as better analgesic efficacy after intranasal administration than that after intragastric administration. DCXFEE has no sedative activity on potentiation of pentobarbital-induced sleep in mice given by both routes. Ligustilide might represents the potential major bioactive component of DCXFEE after intranasal administration and contribute to its analgesic activity in vivo.