Evaluation of Analgesic Activity of Eremostachys laciniata in Mice

Eremostachys laciniata (L.) Bunge (family: Lamiaceae) is one of the fifteen endemic Iranian herbs of the genus Eremostachys, and also grows in other central and western Asian countries. In the Iranian traditional medicine, this plant has been used as a local analgesic and as an anti-inflammatory remedy. In the present study, the methanol (MeOH) extract of the rhizomes of E. laciniata as well as the solid-phase extraction (SPE) fractions have been evaluated for their analgesic property in mice using the hot-plate test. All doses of the SPE 20% aq. MeOH fraction (P < 0.01) and the MeOH extract at the doses of 0.5 mg/kg (P < 0.01) and 1 mg/kg (P<0.05) displayed considerable analgesic effects. The analgesic effect of the SPE 20% aq. MeOH fraction (2.5 mg/kg) was more potent than that of the positive control, morphine (9 mg/kg) at 45 min after injection (P<0.001). However, SPE 40% aq. MeOH fraction did not show any analgesic effects at test doses.