The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A inhibit enteric cholinergic transmission in the guinea-pig ileum.
Neurogastroenterology and motility January 1, 2006 R Capasso, F Borrelli, F Capasso et al. 56 citations
An extract from the hallucinogenic herb Salvia divinorum reduces nerve-induced muscle contractions in guinea-pig ileum by acting on kappa-opioid receptors. The extract lowered electrically evoked contractions without affecting responses to added acetylcholine, indicating a prejunctional site of action. This effect was blocked by the opioid antagonist naloxone and the kappa-opioid antagonist nor-binaltorphimine, but not by antagonists for delta- or mu-opioid receptors or other receptors. Salvinorin A, the main active ingredient, similarly inhibited contractions. The findings suggest that kappa-opioid receptor activation underlies the herb's traditional antidiarrhoeal use.