Inhibition of the mechanical activity of mouse ileum by cactus pear (Opuntia Ficus Indica, L, Mill.) fruit extract and its pigment indicaxanthin.

We investigated, using an organ bath technique, the effects of a hydrophilic extract from Opuntiaficus indica fruit pulp (cactus fruit extract, CFE) on the motility of mouse ileum, and researched theextract component(s) responsible for the observed responses. CFE (10-320 mg of fresh fruit pulpequivalents/mL of organ bath) reduced dose-dependently the spontaneous contractions. This effectwas unaffected by tetrodotoxin, a neuronal blocker, Nω-nitro-L-arginine methyl ester, a nitric oxidesynthase blocker, tetraethylammonium, a potassium channel blocker, or atropine, a muscarinicreceptor antagonist. CFE also reduced the contractions evoked by carbachol, without affecting thecontractions evoked by high extracellular potassium. Indicaxanthin, but not ascorbic acid, assayedat concentrations comparable with their content in CFE, mimicked the CFE effects. The data showthat CFE is able to exert direct antispasmodic effects on the intestinal motility. The CFE inhibitoryeffects do not involve potassium channels or voltage-dependent calcium channels but ratherpathways of calcium intracellular release. The fruit pigment indicaxanthin appears to be the maincomponent responsible for the CFE-induced effects.