Studies on the use of Zizyphus spina-christi against pain in rats and mice

Zizyphus spina-christi (Rhamnaceae) grows wild in tropical Africa and Asia and can be domesticated. It has folkloric usage in pain related ailments throughout these regions. In view of the claimed therapeutic potentials, investigation of the plant’s root bark was initiated in our laboratory. The plant material was first sequentially extracted with hexane, chloroform, ethylacetate and methanol, and in this report, a fraction (numbered) ZS-4D from the methanol extract eluted with 70:30% (chloroform : methanol) using flash column chromatography was apparently traced to be responsible for its main analgesic, and in addition, anti-inflammatory activities. The fraction (25, 50 and 100 mg/kg, i.p.) was tested on chemical (acetic acid-induced writhing, formalin), mechanical (analgesy-meter) and thermal (tail-flick) analgesic tests with the aim of elucidating both central and peripherally mediated action in rats and mice. Its antiinflammatory action against egg albumin-induced hind paw oedema was also tested in rats. Results show that the fraction has some levels of dose related effect on all the models except the tail-flick test in which the activity was not statistically significant.