Effects of piperazine citrate and of the anti-Ascaris fraction of the ethanolic extract of the bark of Polyadoa umbellata (erin) on mammalian non-vascular smooth muscle.

At 500 micrograms-4 mg/ml piperazine and the anti-Ascaris fraction of the ethanolic extract of the bark of the erin tree (Polyadoa umbelleta) have equipotent inhibitory effects on submaximal contractions induced by equipotent doses of acetylcholine, nicotine and 5-hydroxytryptamine on the guinea-pig ileum and the rabbit duodenum. Similar inhibitory effects were noted on: acetylcholine, adrenaline, histamine, and barium chloride-induced contractions in the guinea-pig vas deferens, oxytocin and acetylcholine-induced contractions in the non-pregnant rat uterus. These actions indicate that piperazine and erin possess definite non-specific smooth muscle depressant properties. The need for the elucidation of the chemical nature of the active constituent in "erin" and for in-vivo anti-Ascaris activity studies in man is stressed.