Midori Kashiwagi

Antitumor Activity in Mice of Tentacles of Two Tropical Sea Annelids

Crude extracts of tentacles of two polychaetous annelids completely inhibit growth of Erlich ascites tumor in 60 to 100 percent of treated mice. Dialyzed extracts of one of these annelids, Lanice conchilega, show activity in the retentate after pronase digestion, suggesting that antitumor activity is associated with a nonprotein component of the crude tentacle extract.

A possible mechanism of action of a central stimulant substance isolated from the sea anemone Stoichactis enti

Abstract An active fraction causing central stimulation (evidence as fighting episodes) in mice has been isolated from a sea anemone, most probably Stoichactis kenti . It was found to be a basic polypeptide. The ED 50 of the active fraction was 6.4 mg/kg (i.p.) and LD 50 was 12.2 mg/kg (i.p.). The antagonism of the active fraction-induced stimulant activity by phenobarbital sodium, chlorpromazine and methocarbamol suggests that this activity was probably mediated centrally. Reserpine or tetrabenazine, but not α-methyl-p-tyrosine (α-MPT) pretreatment, decreased the ED 50 of the active fraction. D,L-Dopa treatment also decreased the ED 50 of the active fraction and restored the stimulant action after its abolition by combined treatment with α-MPT and reserpine or α-MPT and disulfiram. These results suggest that a central adrenergic mechanism plays a major role in this stimulant action of the active substance; inhibition by β-adrenoceptor antagonists also support this hypothesis. Interactions with cholinergic and anticholinergic drugs also exist which are not incompatible with this hypothesis.