Smilax canariensis Brouss. ex Willd. is an endemic plant of the Canary Islands. Its rhizomes, leaves and stems have been traditionally used in Canary folk medicine to treat a wide variety of conditions including pain. Our objective is to investigate the analgesic and anti-inflammatory activities of different extracts of S. canariensis in Swiss mice, using established biological models for pain and inflammation, such as phenylquinone writhing test, formalin test, tail-flick test and mouse paw edema induced by carrageenan. Oral administration of S. canariensis extracts significantly reduce writhing episodes evoked by phenylquinone injection in a dose-dependent manner;and higher doses result in a reduction of pain similar to or higher than that of the reference drug piroxicam (59.56%;p < 0.01). The extracts also cause a marked dose-dependent inhibition of for-malin-induced pain in the second phase but only minimal inhibition of tail-flick behavior, suggesting that S. canariensis is not a centrally acting analgesic. Finally, in the carrageenan-induced hind paw edema model, the extracts show a moderate anti-inflammatory effect, the most active being the ethyl acetate fraction at 200 mg/kg p.o. (33.33%;p < 0.05). Our results suggest that S. canariensis extracts have clear dose-dependent peripheral analgesic effects, which lends support to the traditional use of this medicinal plant to treat pain associated with inflammatory or other processes.
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