Endothelium-dependent vasodilator effect of extract prepared from the seeds ofAreca catechuon isolated rat aorta

Arecae semen extract relaxed aortic ring preparations of isolated rat aorta that contained endothelium from 3×10−7 g/mL, reaching a maximum of 86% at 10−5 g/mL. Its relaxation did not occur in specimens without endothelium, and was inhibited by pretreatment with 10−4 MNG-nitro-1-arginine methylester. One of the active components was arecoline which is a muscarinic receptor agonist. Another active component was condensed tannin contained in Arecae semen.