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.
An extract from the hallucinogenic plant Salvia divinorum and its active ingredient salvinorin A reduce gut motility in mice, but only during intestinal inflammation. In healthy mice, salvinorin A slowed motility only at high doses, and this effect did not involve kappa-opioid receptors (KOR). Inflammation made salvinorin A more potent at lower doses, and this effect was blocked by KOR antagonists, indicating a switch to KOR-mediated action. A standard KOR agonist did not share this enhanced potency, suggesting salvinorin A may act through additional targets in the inflamed gut.
Mindfulness-based stress reduction (MBSR) is associated with reduced gastrointestinal symptoms and improved quality of life in people with irritable bowel syndrome. In this single-arm intervention study, changes in specific aspects of mindfulness were linked to clinical outcomes, suggesting that cultivating particular mindfulness skills may drive the benefits of MBSR for IBS.