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The hallucinogenic herb Salvia divinorum and its active ingredient salvinorin A inhibit enteric cholinergic transmission in the guinea‐pig ileum
Author(s) -
Capasso R.,
Borrelli F.,
Capasso F.,
Siebert D. J.,
Stewart D. J.,
Zjawiony J. K.,
Izzo A. A.
Publication year - 2006
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/j.1365-2982.2005.00725.x
Subject(s) - pharmacology , naltrindole , (+) naloxone , chemistry , receptor antagonist , antagonist , nalorphine , opioid receptor , opioid , agonist , medicine , receptor
Salvia divinorum is a widespread hallucinogenic herb traditionally employed for divination, as well as a medicament for several disorders including disturbances of gastrointestinal motility. In the present study we evaluated the effect of a standardized extract from the leaves of S. divinorum (SDE) on enteric cholinergic transmission in the guinea‐pig ileum. SDE reduced electrically evoked contractions without modifying the contractions elicited by exogenous acetylcholine, thus suggesting a prejunctional site of action. The inhibitory effect of SDE on twitch response was abolished by the opioid receptor antagonist naloxone and by the κ ‐opioid antagonist nor‐binaltorphimine, but not by naltrindole (a δ ‐opioid receptor antagonist), CTOP (a μ ‐opioid receptor antagonist), thioperamide (a H 3 receptor antagonist), yohimbine (an α 2 ‐receptor antagonist), methysergide (a 5‐hydroxytryptamine receptor antagonist), N G ‐nitro‐ l ‐ arginine methyl ester (an inhibitor of NO synthase) or apamin (a blocker of Ca 2+ ‐activated K + channels). Salvinorin A, the main active ingredient of S. divinorum , inhibited in a nor‐binaltorphimine‐ and naloxone‐sensitive manner electrically induced contractions. It is concluded that SDE depressed enteric cholinergic transmission likely through activation of κ ‐opioid receptors and this may provide the pharmacological basis underlying its traditional antidiarrhoeal use. Salvinorin A might be the chemical ingredient responsible for this activity.