Neuropharmacological actions of Portulaca oleraceae L v. sativa (Hawk)

Portulaca oleracea L v. sativa (family: Portulacaceae) is a warm-climate annual, cultivated in the Arabian peninsula and used traditionally for alleviating pain and swelling. It was observed that a 10% ethanolic extract of this plant produced restriction of movement in animals during the routine screening studies. Therefore the effects of the extract on the locomotor activity, threshold to noxious stimulus, anti-convulsant activity and relaxant effects on the skeletal muscle were studied. The extract, on intraperitoneal administration, showed a significant reduction in the locomotor activity in mice, anti-nociceptive activity in rats using Tail Flick Method, an increase in the onset time of pentylenetetrazole-induced convulsions in mice and muscle relaxant activity in in vitro (rat hemidiaphragm) and in vivo (grip strength) experiments. The anti-nociceptive activity of the extract in rats was attenuated by naloxone pre-treatment indicating the involvement of opioid receptors in its anti-nociceptive effects. It is indicated from the results of the present study that P. oleracea v. sativa possesses varied effects on both the central and peripheral nervous system and the plant should be exhaustively studied for other neuropharmacological effects.