Analgesic properties of some ethiopian medicinal plants in different models of nociception in mice.

Many people use analgesic plants to relieve pain and inflammation though most of them have not yet been proved to possess such properties. The objective of the present study was to screen the aqueous and ethanol extracts of four Ethiopian traditionally used medicinal plants for analgesic properties. Aqueous and ethanol extracts of the plant materials were screened for their analgesic properties in mice using tail-flick, hot-plate and tail-pinch tests at three dose levels. Normal saline and standard analgesics were employed as negative and positive controls, respectively. The plants subject for the present screening were Ocimum suave, Ocimum lamiifolium, Lippia adoensis, and Ajuga remota. All extracts were observed to possess analgesic properties with varying potencies in tail-flick and hot-plate tests. Analgesic activity, however was not observed with tail-pinch test. The analgesic potencies also varied with concentrations and time after administration. From the present findings, it can be concluded that the extracts of all the plant materials have got analgesic properties with fast onset of action whose mechanisms need to be investigated further. Copyright 2003 John Wiley & Sons, Ltd.